CN107308667B - A kind of isothermal double-effect concentrating unit and concentrating method thereof - Google Patents

Abstract

The invention discloses an isothermal double-effect concentration unit and a concentration method thereof, wherein the isothermal double-effect concentration unit comprises a double-effect concentration system and a secondary steam recompression system, wherein the double-effect concentration system sequentially comprises a raw material tank, a preheating unit, an isothermal concentration tower body, a same-body double-effect heater and a paste collecting tank from upstream to downstream; a secondary steam collecting cavity is formed between the isothermal concentration tower body and the double-effect heater with the same body; the first effect I tube pass and the first effect II tube pass are falling film concentration modules, and the second effect I tube pass is a forced circulation concentration module. The falling film concentrating module and the forced circulation concentrating module are integrated, the falling film concentrating module and the forced circulation concentrating module are different from a single-function concentrating machine in the prior art, two concentrating machines, namely a falling film concentrating machine and a forced circulation concentrating machine, are not required to be arranged, the investment cost and the occupied space are saved, a separation tank is not required to be arranged, and a conveying pipeline between each effect process is saved; and each module can independently adjust the concentration speed and the concentration amount of each tube pass to adapt to different production requirements, so that the use flexibility is improved.

Description

A kind of isothermal double-effect concentrating unit and concentrating method thereof

technical field

The invention relates to the technical field of concentration and evaporation equipment, in particular to an isothermal double-effect concentration unit and a concentration method thereof.

Background technique

At present, the liquid concentration and evaporation technologies used in medicine and food mainly include falling film concentration and forced circulation concentration. Falling film concentration is to add the feed liquid from the upper tube box of the heating chamber of the falling film evaporator, and evenly distribute it into each heat exchange tube through the liquid distribution and film forming device, under the action of gravity and airflow, form a uniform film from top to bottom. The forced circulation concentration uses a circulating pump to force the liquid to flow in the equipment. Falling film concentration has low energy consumption but is easy to scale, while forced circulation concentration is not easy to scale but consumes a lot of energy. Therefore, in actual production, multiple falling-film evaporators and multiple forced circulation evaporators are often used in combination, but the investment cost is high, and a large number of separation tanks and conveying pipelines need to be set up, which takes up a lot of space and is not suitable for small batch production. . Moreover, since the Chinese herbal medicine extract contains some macromolecular substances (such as polysaccharides, starch, colloid, etc.), particulate dirt and biofouling mixture, etc., the Chinese herbal medicine solution is very easy to coagulate and cause scaling, and it is not suitable to use falling film concentration. The forced circulation concentration with high energy consumption is often used for Chinese herbal medicine extracts.

SUMMARY OF THE INVENTION

The purpose of the present invention is to propose an isothermal double-effect concentrating unit and its concentrating method that integrates falling film concentration and forced circulation concentration, saves input cost and occupied space, and is flexible in use, suitable for the concentration of Chinese herbal medicine extracts.

For this purpose, the present invention adopts the following technical solutions:

An isothermal double-effect concentrating unit includes a double-effect concentrating system and a secondary vapor recompression system, the double-effect concentrating system and the secondary vapor recompressing system are connected, and the double-effect concentrating system sequentially includes a raw material tank from upstream to downstream , preheating unit, isothermal concentration tower body, one-body double-effect heater and ointment collecting tank;

The isothermal concentration tower body is sleeved on the outside of the same-body double-effect heater, and a secondary steam collecting cavity is formed between the isothermal concentration tower body and the same-body double-effect heater;

The one-body double-effect heater includes a main casing, an upper head, an upper tube plate, a lower tube plate and a plurality of heat exchange tubes, the upper tube plate is arranged on the upper end of the main casing, and the The lower end is provided with the lower tube plate, and the upper end of the main shell is sealed with the upper head; the upper tube plate and the lower tube plate are distributed with a plurality of installation holes for heat exchange tubes, and the plurality of heat exchange tubes pass through the The heat pipe mounting holes are vertically installed in an array between the upper tube sheet and the lower tube sheet;

It also includes an upper sealing baffle and a lower sealing baffle, the upper sealing baffle is arranged in the inner cavity of the upper sealing head and divides the inner cavity of the upper sealing head into three upper sealing cavities, and the lower sealing baffle is arranged in the inner cavity of the upper sealing head. The bottom of the isothermal concentration tower body is divided into three concentration pools, and the double-effect heater of the same body is arranged on the top of the lower sealing baffle; Divide the tube process of the same body double effect heater into I effect I tube process, I effect II tube process and II effect I tube process;

The upper sealing chambers of the I effect I tube pass and the I effect II tube pass are all provided with water distributors, the I effect I tube pass and the I effect II tube pass are falling film concentration modules, and the II effect I tube pass Concentrate modules for forced circulation.

Preferably, the upper sealing cavity of the I effect I tube pass is communicated with the preheating unit through a pipeline, and the concentration pool of the I effect I tube pass is communicated with the upper sealing cavity of the I effect II tube pass through a pipeline. The concentration pool of the II tube pass is communicated with the upper sealing cavity of the II effect I tube pass through the pipeline, and the concentration pool of the II effect I tube pass is communicated with the cream collecting tank through the pipeline.

Preferably, the water distributor includes a liquid storage tank and a liquid inlet pipe, the liquid inlet pipe is in communication with the liquid storage tank, and the sealed end of the liquid inlet pipe extends toward the interior of the liquid storage tank, and the liquid inlet pipe A section of the liquid storage tank is provided with a plurality of liquid inlet holes;

The bottom of the liquid storage tank is provided with a plurality of liquid distribution branch pipes, the liquid distribution branch pipes and the heat exchange pipes are aligned one by one, and the liquid distribution branch pipes are inserted into the corresponding heat exchange pipes; The bottom of the liquid distribution branch pipe is sealed, and the side wall of the liquid distribution branch pipe is provided with a plurality of liquid spray holes.

Preferably, the double-effect concentration system further comprises a falling film circulating pump, a falling film regulating valve, a first forced circulating pump, a first forced circulating regulating valve and a liquid outlet pump;

The liquid inlet of the falling film circulating pump is communicated with the concentration tank of the I effect I tube pass through a pipeline, and the liquid outlet of the falling film circulating pump is connected to the liquid inlet pipe of the water distributor located in the I effect II tube pass through the pipeline. The open end of the falling film regulating valve is connected with the concentrating tank of the I effect II tube side through a pipeline, and the liquid outlet of the falling film regulating valve is connected with the liquid inlet of the falling film circulating pump through a pipeline ;

The liquid inlet of the first forced circulation pump is communicated with the concentration pool of the I effect II tube side through the pipeline, and the liquid outlet of the first forced circulation pump is communicated with the upper sealing cavity of the II effect I tube side through the pipeline, so The liquid inlet of the first forced circulation regulating valve is communicated with the concentration pool of the II-effect I tube side through a pipeline, and the liquid outlet of the first forced circulation regulating valve is communicated with the liquid inlet of the first forced circulation pump through a pipeline;

The liquid inlet of the liquid outlet pump is communicated with the concentration tank of the II-effect I tube pass through a pipeline, and the liquid outlet of the liquid outlet pump is communicated with the ointment collection tank through a pipeline.

Preferably, the double-effect concentration system further comprises a falling-film frequency converter and a density meter, the falling-film frequency converter and the falling-film circulating pump are electrically connected, and the falling-film frequency converter controls the rotational speed of the falling-film circulating pump;

The detection end of the density meter is communicated with the concentration pool of the II effect I tube pass.

Preferably, the secondary vapor recompression system further comprises a centrifugal compressor, a heated steam output pipe and a secondary steam input pipe, one end of the secondary steam input pipe is communicated with the input port of the centrifugal compressor, and the two The other end of the secondary steam input pipe is communicated with the isothermal concentration tower body, and one end of the heated steam output pipe is communicated with the output port of the centrifugal compressor;

It also includes a heating outer casing, the heating outer casing is arranged around the outer side of the upper part of the main casing to form a heating and sealing cavity, and the side wall of the main casing corresponding to the heating outer casing is provided with a plurality of two a secondary steam input through hole, and the other end of the heating steam output pipe is communicated with the heating outer shell;

The middle part of the lower sealing baffle is provided with a bearing convex surface, and the one-body double-effect heater is arranged on the bearing convex surface.

Preferably, the preheating unit includes a liquid feed pump, a raw material regulating valve, an output three-way control valve, a primary heat exchanger, a secondary heat exchanger, a condensed water storage tank, a water purification tank, an input three-way control valve and Water purification control valve, the liquid inlet of the raw material regulating valve is connected with the raw material tank through the pipeline, the liquid outlet of the raw material regulating valve is connected with the liquid inlet of the liquid inlet pump through the pipeline, and the liquid outlet of the liquid inlet pump is connected The port is communicated with the liquid inlet of the output three-way control valve, and the first liquid outlet of the output three-way control valve is communicated with the open end of the liquid inlet pipe of the water distributor located in the I effect I pipe side through a pipeline;

The first liquid inlet of the input three-way control valve is communicated with the water purification tank through a pipeline, and the second liquid inlet of the input three-way control valve is communicated with the liquid outlet of the raw material regulating valve through a pipeline. The liquid outlet of the control valve is communicated with the liquid inlet of the liquid inlet pump through a pipeline; the liquid inlet of the water purification control valve is communicated with the concentration pool of the II-effect I tube side through a pipeline, and the outlet of the said purification control valve is connected. The liquid port is communicated with the condensed water storage tank through a pipeline;

The one-body double-effect heater also includes a condensed water output pipe, one end of the condensed water output pipe is communicated with the main shell, and the other end of the condensed water output pipe is communicated with the working medium inlet of the primary heat exchanger, so the The working medium outlet of the primary heat exchanger is communicated with the condensed water storage tank through a pipeline, and the liquid inlet of the primary heat exchanger is communicated with the second liquid outlet of the output three-way control valve through a pipeline. The liquid inlet of the heat exchanger is communicated with the liquid outlet of the primary heat exchanger through a pipeline, and the liquid outlet of the secondary heat exchanger is communicated with the first liquid outlet of the output three-way control valve through a pipeline, The working medium inlet of the secondary heat exchanger is connected to a boiler through a pipeline, and the working medium outlet of the secondary heat exchanger is connected to a steam discharge pipe.

Preferably, the one-body double-effect heater further comprises a non-condensable gas output pipe and a plurality of shutoff plates, and the non-condensable gas output pipe is communicated with the main casing;

A plurality of the blocking plates are arranged inside the main casing, one side of the plurality of blocking plates is connected with the inner wall of the main casing, and the other sides of the plurality of blocking plates are formed between the main casing and the main casing. The gaps are arranged in an S shape.

Preferably, the concentration method of the isothermal double-effect concentration unit includes a solution concentration process and a secondary steam cycle process:

The solution concentration process includes the following steps:

Step A, after the low-temperature solution stored in the raw material tank is heated into a high-temperature solution by a preheating unit, it enters the first-effect I tube process of the same body double-effect heater;

Step B, after the high temperature solution enters the upper sealing cavity of the I effect I tube side, the water distributor of the I effect I tube side evenly distributes the high temperature solution to each heat exchange tube of the I effect I tube side. Under the action of gravity, the high-temperature solution flows to the concentration tank of the I effect I tube side in a film shape for falling film concentration;

Step C, the falling film circulating pump extracts the high temperature solution in the concentration tank of the I effect I tube pass and transports it to the upper sealing cavity of the I effect II tube pass, and the water distributor of the I effect II tube pass evenly distributes the high temperature solution. In each heat exchange tube of the I effect II tube pass, the high temperature solution in the heat exchange tube flows to the concentration pool of the I effect II tube pass in a film form under the action of gravity, and performs falling film concentration;

When the high temperature solution in the concentration tank of the I effect II tube pass does not reach the required concentration of the falling film, the falling film regulating valve is opened, and the falling film circulating pump transports the high temperature solution in the concentration pool of the I effect II tube pass back to the I effect II tube. Falling film concentration is carried out in the upper sealing chamber of the tube process until the high temperature solution in the concentration tank of the I effect II tube process reaches the required concentration of the falling film;

Step D, the first forced circulation pump transports the high temperature solution that reaches the required concentration of falling film to the upper sealing cavity of the II effect I tube side, and then performs forced circulation concentration in the heat exchange tube of the II effect I tube side, and the concentrated high temperature solution is obtained. The liquid is concentrated in the concentration tank of the II effect I tube;

When the high-temperature solution in the concentration tank of the II effect I tube pass does not reach the required concentration, the first forced circulation regulating valve is opened, and the first forced circulation pump transports the high temperature solution in the II effect I tube pass concentration tank back to the II effect The upper sealing chamber of the I tube side is forced to circulate and concentrate until the high temperature solution in the concentration pool of the II effect I tube side reaches the required concentration of the liquid;

Step E, the liquid discharge pump transports the high temperature solution that reaches the required concentration of the liquid to the cream collecting tank for storage;

The secondary steam cycle process includes:

First, the secondary steam in the isothermal concentration tower enters the centrifugal compressor through the secondary steam input pipe for compression and heating, and then enters the main casing through the heating steam output pipe to exchange heat with the heat exchange pipe in the main casing;

Then, the secondary steam after heat exchange is condensed into liquid, which is transported to the condensed water storage tank through the condensed water output pipe, and the non-condensable gas is discharged through the non-condensable gas output pipe.

Preferably, a cleaning process is also included:

When the high-temperature solution is completely transported from the I effect I tube pass to the I effect II tube pass, that is, when there is no high temperature solution in the concentration pool of the I effect I tube pass, the pure water stored in the water purification tank is transported to the upper part of the I effect I tube pass. Sealing cavity, flushing the upper sealing cavity, heat exchange tube and concentration tank of I effect I tube side;

When the high temperature solution is completely transported from the I effect II tube pass to the II effect I tube pass, that is, when there is no high temperature solution in the concentration tank of the I effect II tube pass, the falling film circulating pump will extract the pure water in the concentration pool of the I effect I tube pass. The water is transported to the upper sealing chamber of the I effect II tube side, and the upper sealing chamber, the heat exchange tube and the concentration tank of the I effect II tube side are flushed;

When the high-temperature solution is completely transported from the II effect I tube pass to the cream collecting tank, that is, when there is no high temperature solution in the concentration tank of the II effect I tube pass, the first forced circulating pump will extract the pure water in the concentration tank of the I effect II tube pass It is transported to the upper sealing cavity of the II effect I tube pass, and the upper sealing cavity, the heat exchange tube and the concentration tank of the II effect I tube pass are flushed;

After the second effect I tube pass is flushed, the clean water control valve is opened, and the pure water in the concentration tank of the II effect I tube pass is transported to the condensed water storage tank for storage.

The isothermal double-effect concentrating unit is equipped with the double-effect concentrating system for the concentration of the Chinese herbal medicine solution, and the Chinese herbal medicine stock solution with lower concentration is stored in the raw material tank. It is evaporated and concentrated, and then the high-temperature Chinese herbal medicine stock solution enters the double-effect heater of the same body, and passes through the I-effect I tube process, the I-effect II tube process and the II-effect I tube process in turn. The Chinese herbal medicine slurry with higher concentration is transported to the ointment collection tank for storage. The integrated falling-film concentrating module and forced circulation concentrating module are different from the existing single-function concentrators. There is no need to set up two concentrators, the falling-film concentrator and the forced circulation concentrator, which saves the input cost and occupied space. There is no need to set up a separation tank. It can remove the conveying pipeline between each effect process; and each module can independently adjust the concentration speed and concentration of each tube process to adapt to different production requirements and improve the flexibility of use.

Description of drawings

The accompanying drawings further illustrate the present invention, but the content in the accompanying drawings does not constitute any limitation to the present invention.

Fig. 1 is the structural representation of the isothermal double-effect concentrating unit of one of the embodiments of the present invention;

Fig. 2 is the top view of the isothermal double-effect concentrating unit of one embodiment of the present invention;

Fig. 3 is the front view structure diagram of the double-effect concentrating unit of one of the embodiments of the present invention;

4 is an enlarged view of the top view structure of the double-effect concentrating unit of one embodiment of the present invention;

5 is a half-section structural view of a water distributor according to an embodiment of the present invention;

Fig. 6 is the bottom structural view of the water distributor of one embodiment of the present invention;

Fig. 7 is the use state diagram of the water distributor of one embodiment of the present invention;

8 is a structural diagram of a liquid distribution branch pipe according to an embodiment of the present invention;

FIG. 9 is a structural diagram of a preheating unit according to one embodiment of the present invention.

Among them: one-body double-effect heater 1; raw material tank 2; ointment collecting tank 5; main shell 11; upper sealing head 12; isothermal concentration tower body 13; upper tube plate 14; lower tube plate 15; Sealing baffle 121; lower sealing baffle 132; I effect I tube 81; I effect II tube 82; II effect I tube 83; water distributor 122; liquid storage tank 123; liquid inlet pipe 124; 125; liquid inlet hole 126; liquid injection hole 127; falling film circulating pump 4; falling film regulating valve 41; first forced circulating pump 51; first forced circulating regulating valve 52; liquid outlet pump 53; falling film frequency converter 42; Density meter 54; centrifugal compressor 6; heating steam output pipe 61; secondary steam input pipe 62; heating outer shell 17; secondary steam collecting chamber 131; bearing convex surface 133; ; Output three-way control valve 31; Primary heat exchanger 32; Secondary heat exchanger 33; Condensate storage tank 34; Condensate output pipe 111; 72; non-condensable gas output pipe 112; blocking plate 19.

Detailed ways

The technical solutions of the present invention are further described below with reference to the accompanying drawings and through specific embodiments.

The isothermal double-effect concentrating unit of this embodiment, as shown in Figures 1 and 3, includes a double-effect concentrating system and a secondary vapor recompression system. The double-effect concentrating system is connected to the secondary vapor recompression system. The high-efficiency concentration system includes, from upstream to downstream, a raw material tank 2, a preheating unit, an isothermal concentration tower 13, a single double-effect heater 1 and a cream collecting tank 5;

As shown in FIG. 3 , the isothermal concentration tower body 13 is sleeved on the outside of the same-body double-effect heater 1 , and a secondary steam collecting cavity is formed between the isothermal concentration tower body 13 and the same-body double-effect heater 1 131;

The one-body double-effect heater 1 includes a main casing 11 , an upper head 12 , an upper tube sheet 14 , a lower tube sheet 15 and a plurality of heat exchange tubes 16 . The upper end of the main casing 11 is provided with the upper tube sheet 14. The lower tube plate 15 is provided at the lower end of the main casing 11, and the upper end of the main casing 11 is sealed with the upper head 12; the upper tube plate 14 and the lower tube plate 15 are distributed with multiple a plurality of heat exchange tube installation holes, and a plurality of heat exchange tubes 16 are vertically installed between the upper tube plate 14 and the lower tube plate 15 in an array through the heat exchange tube installation holes;

It also includes an upper sealing baffle 121 and a lower sealing baffle 132. The upper sealing baffle 121 is arranged in the inner cavity of the upper sealing head 12 and divides the inner cavity of the upper sealing head 12 into three upper sealing cavities. The sealing baffle 132 is arranged at the bottom of the isothermal concentration tower body 13 and is divided into three concentration pools, and the one-body double-effect heater 1 is arranged on the top of the lower sealing baffle 132; and the upper sealing baffle 121 and the lower sealing baffle 132 are set up and down opposite to each other, so that the tube side of the double-effect heater 1 is divided into I effect I tube side 81, I effect II pipe side 82 and II effect I pipe side 83, as shown in Figure 2 and Figure 4 shown;

As shown in FIG. 3 , the upper sealing chambers of the I effect I tube 81 and the I effect II tube 82 are provided with a water distributor 122 , and the I effect I tube 81 and the I effect II tube 82 are the lowering Membrane concentration module, the second effect I tube 83 is a forced circulation concentration module.

Preferably, as shown in FIG. 2 , the upper sealing cavity of the I-effect I tube pass 81 is communicated with the preheating unit through a pipeline, and the concentration pool of the I-effect I tube pass 81 is connected to the I effect II tube pass 82 through a pipeline. The upper sealing cavity is connected, the concentration pool of the I effect II tube pass 82 is communicated with the upper sealing cavity of the II effect I tube pass 83 through the pipeline, and the concentration pool of the II effect I tube pass 83 is communicated with the cream collecting tank 5 through the pipeline. .

The isothermal double-effect concentration unit is equipped with the double-effect concentration system for the concentration of the Chinese herbal medicine solution, the Chinese herbal medicine stock solution with lower concentration is stored in the raw material tank 2, and the Chinese herbal medicine stock solution is first heated by the preheating unit during concentration. In order to facilitate evaporation and concentration, the high-temperature Chinese herbal medicine stock solution enters the same body double-effect heater 1, and passes through the I effect I tube process 81, the I effect II tube process 82 and the II effect I tube process 83 in turn. The forced circulation is concentrated to make a high-concentration Chinese herbal medicine slurry and transport it to the ointment collecting tank 5 for storage.

The upper sealing head 12 of the one-body double-effect heater 1 is the input port of the Chinese herbal medicine solution, and the Chinese herbal medicine solution in the upper sealing head 12 flows into each heat exchange tube 16 along the upper tube plate 14 for evaporation and concentration. The Chinese herbal medicine solution is collected in the lower box. The same body double effect heater 1 divides the tube process of the same body dual effect heater 1 into I effect I tube process 81 and I effect II tube process 82 through the upper sealing baffle 121 and the lower sealing baffle 132 arranged up and down oppositely. and II effect I tube pass 83; each tube pass from top to bottom includes an upper sealing cavity, a concentration pool, and a heat exchange tube 16 corresponding to that part of the space between the upper sealing cavity and the concentration pool, so that the interior of the main shell 11 The plurality of heat exchange tubes 16 are divided into three areas, so that the Chinese herbal medicine solution can be evaporated and concentrated in the same body double-effect heater 1 for multiple cycles, and there is no need for multiple single body double-effect heaters 1 to prolong the evaporation and concentration process of the Chinese herbal medicine solution and save costs. and space.

Moreover, since Chinese herbal medicine extracts mostly contain some macromolecular substances (such as polysaccharides, starches, colloids, etc.), particulate dirt and biofouling mixtures, etc., Chinese herbal medicine solutions are very easy to coagulate and cause scaling. Therefore, the isothermal double-effect concentration unit sets the falling film concentration that is easy to scale in the I effect I tube pass 81 and the I effect II tube pass 82, which are used for concentrating the Chinese herbal medicine stock solution with a lower concentration, and the Chinese herbal medicine stock solution with a lower concentration is not easy to Scaling; the water distributor 122 can evenly distribute the Chinese herbal medicine stock solution to each heat exchange tube 16, and the Chinese herbal medicine stock solution in the heat exchange tube 16 flows to the concentration tank in a film shape under the action of gravity. The evaporation rate of the falling film concentrator is slow, in order to reach the standard once the concentration, the heat exchange tube 16 is long; but the evaporation rate of the forced circulation concentrator is fast, and the heat exchange tube 16 is short; The membrane concentration module is set to two tube passes: I effect I tube pass 81 and I effect II tube pass 82, and the forced circulation concentration module only needs one tube pass, which not only shortens the length of the heat exchange tube 16, but also avoids the forced circulation concentration module. The consumption is large, and the concentration quality of the falling film concentration module can be guaranteed.

The forced circulation concentration with strong anti-scaling ability is set in the second effect I tube 83, which is used to concentrate the Chinese herbal medicine solution with high concentration and easy to scale. The full tube of Chinese herbal medicine solution falls freely in the heat exchange tube 16. Part of the Chinese herbal medicine solution is heated and vaporized, so that the Chinese herbal medicine solution is sprayed to the concentration tank at a high speed under the impetus of the expanding saturated gas. The one-body double-effect heater 1 integrates a falling film concentrating module and a forced circulation concentrating module, which is different from the existing single-function concentrator, and does not need to set up two concentrators, a falling film concentrator and a forced circulation concentrator, saving input costs and occupation. Space, there is no need to set up separation tanks, and the conveying pipeline between each effect process is omitted; and each module can independently adjust the concentration speed and concentration of each tube process to adapt to different production requirements and improve the flexibility of use.

Preferably, as shown in FIG. 5 , the water distributor 122 includes a liquid storage tank 123 and a liquid inlet pipe 124, the liquid inlet pipe 124 is communicated with the liquid storage tank 123, and the sealing end of the liquid inlet pipe 124 faces The interior of the liquid storage tank 123 extends, and a section of the liquid inlet pipe 124 located in the liquid storage tank 123 is provided with a plurality of liquid inlet holes 126;

As shown in FIG. 6 , the bottom of the liquid storage tank 123 is provided with a plurality of liquid distribution branch pipes 125 , and the liquid distribution branch pipes 125 and the heat exchange pipes 16 are aligned one by one, and the liquid distribution branch pipes 125 are arranged one by one. 125 is inserted into the corresponding heat exchange pipe 16, as shown in FIG. 7; the bottom of the liquid distribution branch pipe 125 is sealed, and the side wall of the liquid distribution branch pipe 125 is provided with a plurality of liquid injection holes 127, as shown in FIG. 5 Show.

The water distributor 122 is a closed box, and the Chinese herbal medicine solution is input from the liquid inlet pipe 124, and flows into the liquid storage tank 123 through the liquid inlet hole 126, and then flows to each of the liquid distribution branch pipes 125. Heat exchange tubes 16 . The pressure of the Chinese herbal medicine solution in the liquid storage tank 123 can be adjusted by adjusting the liquid inlet amount of the liquid inlet pipe 124, so as to change the liquid spray amount of the liquid distribution branch pipe 125, thereby achieving the control of the wetting of the heat exchange pipe 16. That is, the initial thickness of the liquid film in the heat exchange tube 16 is controlled, and in the process of making the liquid film flow from the top end to the bottom end of the heat exchange tube 16, although the thickness of the liquid film becomes thinner due to evaporation, when the liquid film flows to the bottom end There is still a thin layer that increases the evaporation rate of the liquid film and avoids dry wall phenomena and scaling.

One end of the liquid inlet pipe 124 located in the liquid storage tank 123 is sealed, and a section of the liquid inlet pipe 124 located in the liquid storage tank 123 is provided with a plurality of liquid inlet holes 126, so that the Chinese herbal medicine solution can flow into the entire liquid storage tank 123 evenly, avoiding The uneven distribution of the Chinese herbal medicine solution in the liquid storage tank 123 results in uneven distribution of the Chinese herbal medicine solution flowing to each heat exchange tube 16 , and can play the role of secondary pressurization to expand the spraying range of the Chinese herbal medicine solution. The bottom of the liquid distribution branch pipe 125 is sealed, the side of the liquid distribution branch pipe 125 is provided with a plurality of liquid spray holes 127, and the Chinese herbal medicine solution is sprayed from the side of the liquid distribution branch pipe 125 to the side wall of the heat exchange pipe 16, which is more conducive to A liquid film is formed at the top of the heat exchange tube 16 ; if the Chinese herbal medicine solution is directly sprayed into the heat exchange tube 16 from the bottom of the liquid distribution branch pipe 125 , the position of the film formation will decrease, resulting in a dry wall phenomenon at the top of the heat exchange tube 16 .

Preferably, as shown in FIG. 8 , the side wall of the liquid dispensing branch pipe 125 is vertically provided with a plurality of the liquid spray holes 127 , so that the Chinese herbal medicine solution is sprayed along the tangent of the side wall of the liquid dispensing branch pipe 125 , and is sprayed on the heat exchange pipe 16 The inner wall of the heat exchange tube 16 is spirally confluent to form a film, which not only ensures that the top of the heat exchange tube 16 is completely wet, but also ensures that the thickness of the formed liquid film is uniform, and bubbles are not easily formed inside the liquid film.

Preferably, as shown in FIGS. 2 to 4 , the double-effect concentration system further includes a falling film circulating pump 4 , a falling film regulating valve 41 , a first forced circulating pump 51 , a first forced circulating regulating valve 52 and a liquid outlet pump 53;

The liquid inlet of the falling film circulating pump 4 is communicated with the concentration tank of the I effect I tube pass 81 through the pipeline, and the liquid outlet of the falling film circulating pump 4 is connected to the water distributor located in the I effect II tube pass 82 through the pipeline. The open end of the liquid inlet pipe 124 of 122 is connected to each other, the liquid inlet of the falling film regulating valve 41 is connected to the concentration tank of the I effect II pipe pass 82 through the pipeline, and the liquid outlet of the falling film regulating valve 41 is connected to the pipeline and the concentration tank. The liquid inlet of the falling film circulating pump 4 is connected;

The liquid inlet of the first forced circulation pump 51 is communicated with the concentration tank of the I-effect II tube pass 82 through a pipeline, and the liquid outlet of the first forced circulation pump 51 is connected to the upper seal of the II-effect I tube pass 83 through a pipeline. The liquid inlet of the first forced circulation regulating valve 52 is communicated with the concentration tank of the II effect I tube 83 through the pipeline, and the liquid outlet of the first forced circulation regulating valve 52 is connected with the first forced circulation through the pipeline. The liquid inlet of the pump 51 is communicated;

The liquid inlet of the liquid outlet pump 53 is communicated with the concentration tank of the II effect I tube 83 through a pipeline, and the liquid outlet of the liquid outlet pump 53 is communicated with the cream collecting tank 5 through a pipeline.

The Chinese herbal medicine stock solution is concentrated into the Chinese herbal medicine solution with lower concentration after preliminary falling film concentration in the I effect I tube pass 81. The falling film circulating pump 4 extracts the Chinese herbal medicine solution in the concentration tank of the I effect I tube pass 81 and transports it to the I effect II The upper sealed chamber of tube pass 82 is further concentrated by falling film. Preferably, the concentration tank of the I effect II tube pass 82 is provided with a liquid level gauge, which is used to detect the storage of the Chinese herbal medicine solution in the concentration tank of the I effect II tube pass 82 . When the liquid level of the Chinese herbal medicine solution is at a low level, the falling film regulating valve 41 is in a closed state, and the falling film circulating pump 4 extracts the Chinese herbal medicine solution in the concentration tank of the I effect I tube 81; when the liquid level of the Chinese herbal medicine solution is at a high level , the falling film regulating valve 41 is opened, and the falling film circulating pump 4 draws the Chinese herbal medicine solution from the concentration tank of the I effect II tube pass 82 to the upper sealing cavity of the I effect II tube pass 82 for further falling film concentration, avoiding the I effect II tube pass. When the storage of the Chinese herbal medicine solution in the concentration tank of the process 82 is too large, it will affect the secondary steam discharge, and prevent the Chinese herbal medicine solution from flowing over the lower sealing baffle 132 to other concentrated tanks when it is too full.

The first forced circulation pump 51 extracts the Chinese herbal medicine solution in the concentration tank of the I effect II tube pass 82 and transports it to the upper sealed cavity of the II effect I tube pass 83 for preliminary forced circulation concentration. Preferably, the concentration tank of the II effect I tube pass 83 is provided with a liquid level gauge, which is used to detect the storage of the Chinese herbal medicine solution in the concentration pool of the II effect I tube pass 83 . When the liquid level of the Chinese herbal medicine solution is at a low level, the first forced circulation regulating valve 52 is in a closed state, and the first forced circulation pump 51 extracts the Chinese herbal medicine solution in the concentration tank of the I effect II tube pass 82; the liquid level of the Chinese herbal medicine solution When in the high position, the first forced circulation regulating valve 52 is opened, and the first forced circulation pump 51 simultaneously extracts the Chinese herbal medicine solution from the concentration pool of the II effect I tube 83 to the upper sealing cavity of the II effect I tube 83 for further forced circulation. Concentration, to avoid secondary steam discharge when the Chinese herbal medicine solution in the concentration tank of II effect I tube pass 83 is too large, and to prevent the Chinese herbal medicine solution from flowing into other concentrated tanks over the lower sealing baffle 132 when it is overfilled.

When the Chinese herbal medicine solution in the concentration tank of the II effect I tube 83 reaches the required concentration of the liquid, the liquid outlet pump 53 extracts the Chinese herbal medicine solution in the concentration tank of the II effect I tube 83 to the ointment collection tank 5 for storage.

Preferably, the bottoms of the three concentration tanks are all provided with slag discharge ports for discharging the medicinal residues deposited on the bottoms of the concentration basins to prevent the medicinal residues from clogging the pipeline.

Preferably, as shown in FIG. 3 , the double-effect concentration system further includes a falling-film frequency converter 42 and a density meter 54 , the falling-film frequency converter 42 is electrically connected to the falling-film circulating pump 4 , and the falling-film frequency converter 42 The speed of the falling film circulating pump 4 is controlled; the detection end of the density meter 54 is communicated with the concentration tank of the II effect I tube 83 . The falling film frequency converter 42 controls the rotating speed of the falling film circulating pump 4, so that the flow rate of the falling film circulating pump 4 is controlled within the range of 18-36 t/h, and then the thickness of the film is controlled, so that the wetting amount of the heat exchange tube 16 is controlled. Appropriate to avoid dry wall phenomenon. The density meter 54 is used to detect the density of the Chinese herbal medicine solution in the concentration tank of the II effect I tube pass 83, to determine whether the liquid discharge requirement is met, and to improve the accuracy and reliability of the concentration. If the density of the Chinese herbal medicine solution is lower than the required density of the liquid, the forced circulation concentration will continue in the second effect I tube 83 of the same double-effect heater 1. If the density of the Chinese herbal medicine solution is equal to or higher than the required density of the liquid, it will be sent to the ointment collection tank 5 to store.

Preferably, as shown in FIGS. 1 and 2 , the secondary steam recompression system further includes a centrifugal compressor 6 , a heated steam output pipe 61 and a secondary steam input pipe 62 . One end is communicated with the input port of the centrifugal compressor 6, the other end of the secondary steam input pipe 62 is communicated with the isothermal concentration tower 13, and one end of the heated steam output pipe 61 is communicated with the output port of the centrifugal compressor 6;

As shown in FIG. 3 , the heating outer casing 17 is further included. The heating outer casing 17 is arranged around the outer side of the upper part of the main casing 11 to form a heating and sealing cavity. The side wall corresponding to the body 17 is provided with a plurality of secondary steam input through holes, and the other end of the heating steam output pipe 61 communicates with the heating outer shell 17; the middle part of the lower sealing baffle plate 132 is provided with a bearing convex surface 133 , the same-body double-effect heater 1 is arranged on the bearing convex surface 133 .

The secondary vapor recompression system is used to collect and reuse the secondary vapor produced by the concentration. The centrifugal compressor 6 sends heating steam to the heating steam output pipe 61 by compressing the heating air, and the heating steam enters the heating outer casing 17 along with the heating steam output pipe 61, and enters the main casing through the secondary steam input through hole. Inside the body 11, the Chinese herbal medicine solution in each heat exchange tube 16 is heated, so that part of the Chinese herbal medicine solution in the heat exchange tube 16 is heated and vaporized, and secondary steam is generated in the heat exchange tube 16, which pushes the Chinese herbal medicine solution to fall along the tube wall, and the secondary steam is generated in the heat exchange tube 16. The steam is discharged from the bottom of the heat exchange tube 16 to the secondary steam collection chamber 131 of the isothermal concentration tower body 13 .

The middle part of the lower sealing baffle 132 is provided with a bearing convex surface 133, and the single-body double-effect heater 1 is arranged on the bearing convex surface 133, so that the bottom of the single-body double-effect heater 1 and the Chinese herbal medicine solution in the concentrated pool are formed. It is separated to prevent the bottom of the same-body double-effect heater 1 from being sealed when the Chinese herbal medicine solution in the concentration pool is too full, so that the secondary steam cannot be discharged, which facilitates the diffusion of the secondary steam and the separation between the solution and the secondary steam.

The discharged secondary steam flows to the secondary steam collecting chamber 131 and the secondary steam input pipe 62 in turn, and finally enters the centrifugal compressor 6 for separation, compression and heating, and is then transported to the heating outer shell through the heating steam output pipe 61 17. Participate in the heat exchange cycle. When the secondary steam is sufficient, the centrifugal compressor 6 no longer compresses the air, and the heating steam is replaced by the secondary steam, which reduces the demand for external energy and reduces the operating cost. The secondary steam collected in the isothermal concentration tower body 13 is isothermal steam, which is convenient for compression treatment; and the discharged secondary steam is collected and reused to reduce external discharge and reduce heat energy waste. The top of the lower sealing box is provided with a bearing convex surface 133, and the secondary steam discharged from the heat exchange tube 16 needs to pass through the bearing convex surface 133 to enter the secondary steam collection chamber 131, which is convenient for the diffusion of the secondary steam, as well as the solution and the secondary steam. separation between.

Preferably, as shown in FIG. 2 and FIG. 9 , the preheating unit includes a liquid feed pump 21, a raw material regulating valve 22, an output three-way control valve 31, a primary heat exchanger 32, a secondary heat exchanger 33, a condenser The water storage tank 34, the water purification tank 7, the input three-way control valve 71 and the water purification control valve 72, the liquid inlet of the raw material regulating valve 22 is communicated with the raw material tank 2 through a pipeline, and the liquid outlet of the raw material regulating valve 22 The port is connected with the liquid inlet of the liquid inlet pump 21 through a pipeline, the liquid outlet of the liquid inlet pump 21 is connected with the liquid inlet of the output three-way control valve 31, and the first liquid outlet of the output three-way control valve 31 is connected. The port is communicated with the open end of the liquid inlet pipe 124 of the water distributor 122 located in the I effect I pipe pass 81 through a pipe;

The first liquid inlet of the input three-way control valve 71 is communicated with the water purification tank 7 through a pipeline, and the second liquid inlet of the input three-way control valve 71 is communicated with the liquid outlet of the raw material regulating valve 22 through a pipeline, The liquid outlet of the input three-way control valve 71 is communicated with the liquid inlet of the liquid inlet pump 21 through a pipeline; the liquid inlet of the water purification control valve 72 is communicated with the concentration pool of the II effect I tube 83 through a pipeline, The liquid outlet of the water purification control valve 72 is communicated with the condensed water storage tank 34 through a pipeline;

The one-body double-effect heater 1 further includes a condensate water output pipe 111 , one end of the condensate water output pipe 111 is communicated with the main casing 11 , and the other end of the condensate water output pipe 111 is connected to the primary heat exchanger 32 . The working medium inlet is connected, the working medium outlet of the primary heat exchanger 32 is communicated with the condensed water storage tank 34 through a pipeline, and the liquid inlet of the primary heat exchanger 32 is connected through a pipeline and the first output of the three-way control valve 31. The two liquid outlets are connected, the liquid inlet of the secondary heat exchanger 33 is connected to the liquid outlet of the primary heat exchanger 32 through a pipeline, and the liquid outlet of the secondary heat exchanger 33 is connected to the liquid outlet through a pipeline. The first liquid outlet of the output three-way control valve 31 is connected, the working medium inlet of the secondary heat exchanger 33 is connected to a boiler through a pipeline, and the working medium outlet of the secondary heat exchanger 33 is connected to a steam discharge pipe.

The condensed water output pipe 111 is used for outputting the condensed water of the main casing 11, and the condensed water is formed by the heat exchange and condensation of the secondary steam and the heat exchange pipe 16, and the condensed water is still at a relatively high temperature. Therefore, these high-temperature condensed water can be used as the working medium of the primary heat exchanger 32 to exchange heat with the Chinese herbal medicine stock solution to heat the Chinese herbal medicine stock solution, but the heating effect is not strong. The primary heat exchanger 32 is a plate-and-frame heat exchanger, which is suitable for the utilization of low-temperature heat sources, and the minimum temperature difference between the two heat exchange media can reach 1°C. The secondary heat exchanger 33 is externally connected with boiler steam as a working medium, and exchanges heat with the Chinese herbal medicine stock solution to heat the Chinese herbal medicine stock solution, with a strong heating effect. The secondary heat exchanger 33 is a tubular heat exchanger, which is suitable for the utilization of a high temperature heat source and has a wide heat exchange temperature range.

The liquid inlet pump 21 extracts the Chinese herbal medicine stock solution in the raw material tank 2, and a thermometer can be set at the liquid inlet of the liquid inlet pump 21 and the liquid outlet of the primary heat exchanger 32 to detect the temperature of the Chinese herbal medicine stock liquid to control the output three-way control valve The switch of the two liquid outlets of 31 and the working state of the secondary heat exchanger 33. When the temperature of the Chinese herbal medicine stock solution is higher than 80°C, the first liquid outlet of the output three-way control valve 31 is opened and the second liquid outlet is closed. Falling film concentration is carried out in the cavity; the temperature of the Chinese herbal medicine stock solution is lower than 80°C, the first liquid outlet of the output three-way control valve 31 is closed and the second liquid outlet is opened, first, the primary heat exchanger 32 performs the Chinese herbal medicine stock solution once Preheat, and then judge whether the temperature of the Chinese herbal medicine stock solution after a preheating reaches 80°C: If the temperature of the Chinese herbal medicine stock solution after a preheating reaches 80°C, the secondary heat exchanger 33 does not work, and the Chinese herbal medicine stock solution is directly delivered to the first effect. Ⅰ The upper sealing chamber of the tube pass 81 is subjected to falling film concentration; if the temperature of the Chinese herbal medicine stock solution after the first preheating is still lower than 80°C, the secondary heat exchanger 33 is started to preheat the Chinese herbal medicine stock solution for the second time, and then transported to Ⅰ The upper sealing cavity of the tube side 81 of the effect I. The preheating unit is provided with a primary heat exchanger 32 and a secondary heat exchanger 33, and the preheating method is selected according to the temperature of the Chinese herbal medicine stock solution, which not only makes full use of the waste heat of the condensed water, but also reduces the use of external heat sources and reduces investment costs. The raw material regulating valve 22 is used to control the output amount and output speed of the Chinese herbal medicine stock solution, and then control the evaporation amount and the evaporation rate of the Chinese herbal medicine stock solution, preferably, the evaporation rate is controlled at 10.5t/h.

The liquid inlet volume of the water distributor 122 located in the I effect I tube pass 81 is controlled by the liquid inlet pump 21. The liquid inlet frequency converter can be set to adjust the speed of the liquid inlet pump 21, and the liquid discharge rate of the liquid inlet pump 21 can be controlled. Thus, the liquid film thickness of the I effect I tube pass 81 is controlled. The liquid inlet of the water distributor 122 located in the I-effect II tube pass 82 is controlled by the falling film circulating pump 4, and the falling film frequency converter 42 controls the speed of the falling film circulating pump 4, thereby controlling the liquid flow in the I effect II tube pass 82. film thickness.

The water purification tank 7 stores pure water, which is used for cleaning the same-body double-effect heater 1; the input three-way control valve 71 is used for controlling whether to clean or not. When concentrating, the first liquid inlet of the input three-way control valve 71 is closed and the second liquid inlet is opened, and the Chinese herbal medicine stock solution is sent to the liquid inlet pump 21; when cleaning, the first liquid inlet of the input three-way control valve 71 is opened and The second liquid inlet is closed, and pure water is sent to the liquid inlet pump 21 to clean the same-body double-effect heater 1. After cleaning, the water purification control valve 72 is opened, and the waste water is sent to the condensed water storage tank 34 for storage.

Preferably, as shown in FIG. 3 , the single-body double-effect heater 1 further includes a non-condensable gas output pipe 112 and a plurality of shutoff plates 19, and the non-condensable gas output pipe 112 is communicated with the main casing 11; The blocking plates 19 are arranged inside the main casing 11 , and one side of the plurality of blocking plates 19 is connected to the inner wall of the main casing 11 , and the other side of the plurality of blocking plates 19 is connected to the main casing 11 . The gaps formed between them are arranged in an S shape. The secondary steam in the main casing 11 is partially condensed into water and discharged through the condensed water output pipe 111 , while the secondary steam that is not condensed into water is discharged through the non-condensable gas output pipe 112 . The interior of the main casing 11 is provided with a blocking plate 19 arranged in an S shape, which is used to guide the secondary steam to flow in an S shape from top to bottom in the main casing 11, thereby prolonging the flow of the secondary steam in the main casing. 11 flow time, then prolong the heat exchange time and improve the concentration quality.

Preferably, the concentration method of the isothermal double-effect concentration unit includes a solution concentration process and a secondary steam cycle process:

The solution concentration process includes the following steps:

Step A, after the low-temperature solution stored in the raw material tank 2 is heated into a high-temperature solution by the preheating unit, it enters the first-effect I tube process 81 of the same body double-effect heater 1;

Step B, after the high temperature solution enters the upper sealing cavity of the I effect I tube pass 81, the water distributor 122 of the I effect I tube pass 81 evenly distributes the high temperature solution to each heat exchange tube 16 of the I effect I tube pass 81, Under the action of gravity, the high-temperature solution in the heat exchange tube 16 flows to the concentration tank of the I effect I tube pass 81 in a film shape to perform falling film concentration;

Step C, the falling film circulating pump 4 extracts the high-temperature solution in the concentration tank of the I effect I tube pass 81 and transports it to the upper sealing cavity of the I effect II tube pass 82, and the water distributor 122 of the I effect II tube pass 82 The high temperature solution is evenly distributed to each heat exchange tube 16 of the I effect II tube pass 82, and the high temperature solution in the heat exchange tube 16 flows to the concentration pool of the I effect II tube pass 82 in the form of a film under the action of gravity, and is lowered. membrane concentration;

When the high temperature solution in the concentration tank of the I effect II tube pass 82 does not reach the required concentration of falling film, the falling film regulating valve 41 is opened, and the falling film circulating pump 4 transports the high temperature solution in the concentration pool of the I effect II tube pass 82 back to The upper sealing chamber of the I effect II tube pass 82 performs falling film concentration until the high temperature solution in the concentration pool of the I effect II tube pass 82 reaches the required concentration of the falling film;

In step D, the first forced circulation pump 51 transports the high temperature solution that reaches the required concentration of falling film to the upper sealing chamber of the II effect I tube pass 83, and then is forced to circulate and concentrate in the heat exchange tube 16 of the II effect I tube pass 83, The concentrated high-temperature liquid is gathered in the concentration tank of II effect I tube pass 83;

When the high temperature solution in the concentration tank of the II effect I tube pass 83 does not reach the mandatory concentration, the first forced circulation regulating valve 52 is opened, and the first forced circulation pump 51 will pump the high temperature solution in the concentration pool of the II effect I tube pass 83 It is sent back to the upper sealing cavity of the II effect I tube pass 83 for forced circulation concentration until the high temperature solution in the concentration pool of the II effect I tube pass 83 reaches the required concentration of the liquid;

Step E, the liquid outlet pump 53 transports the high temperature solution that reaches the required concentration of the liquid to the ointment collecting tank 5 for storage;

The secondary steam cycle process includes:

First, the secondary steam in the isothermal concentration tower body 13 enters the centrifugal compressor 6 through the secondary steam input pipe 62 for compression and heating, and then enters the main casing 11 through the heating steam output pipe 61, and is connected with the main casing 11. The heat exchange tube 16 conducts heat exchange;

Then, the heat-exchanged secondary steam is condensed into liquid, which is transported to the condensed water storage tank 34 through the condensed water output pipe 111 , and the non-condensable gas is discharged through the non-condensable gas output pipe 112 .

The solution concentration process firstly performs scaling-prone falling-film concentration in the I effect I tube pass 81 and the I effect II tube pass 82, which are used to concentrate the Chinese herbal medicine stock solution with lower concentration, and the Chinese herbal medicine stock solution with lower concentration is not easy to scale; The water distributor 122 can evenly distribute the Chinese herbal medicine stock solution to each heat exchange tube 16, and the Chinese herbal medicine stock solution in the heat exchange tube 16 flows down under the action of gravity in the form of a film to seal the box; The strong forced circulation concentration is used to concentrate the Chinese herbal medicine solution with high concentration and easy to scale. The full tube of Chinese herbal medicine solution falls freely in the heat exchange tube 16, and part of the Chinese herbal medicine solution is heated and vaporized during the falling process, so that the Chinese herbal medicine solution expands. Saturated gas is driven by high-speed spray to seal the box downward. Moreover, the solution concentration process also enables the Chinese herbal medicine solution to undergo multiple cycles of concentration in each tube pass until it reaches a predetermined value before entering the next stage tube pass, thereby improving the concentration quality. The secondary steam cycle process simultaneously collects the secondary steam discharged from the three tube passes to replace the heating steam to participate in the heat exchange cycle, thereby reducing the demand for external energy and reducing operating costs. The secondary steam is collected and reused to reduce external emissions and waste of heat energy.

Preferably, a cleaning process is also included:

When the high temperature solution is all transported from the I effect I tube pass 81 to the I effect II tube pass 82, that is, when there is no high temperature solution in the concentration pool of the I effect I tube pass 81, the pure water stored in the water purification tank 7 is transported to the I effect I The upper sealing cavity of the tube pass 81, flushes the upper sealing cavity, the heat exchange tube 16 and the concentration tank of the I effect I tube pass 81;

When the high-temperature solution is completely transported from the I-effect II tube pass 82 to the II-effect I tube-pass 83, that is, when there is no high-temperature solution in the concentration pool of the I-effect II tube-pass 82, the falling film circulating pump 4 draws the liquid in the I-effect I tube pass 81. The pure water in the concentration tank is transported to the upper sealing cavity of the I effect II tube pass 82, and the upper sealing cavity of the I effect II tube pass 82, the heat exchange tube 16 and the concentration pool are flushed;

When the high-temperature solution is completely transported from the II-effect I tube pass 83 to the cream collecting tank 5, that is, when there is no high-temperature solution in the concentration tank of the II-effect I tube-pass 83, the first forced circulation pump 51 extracts the concentrated solution in the I-effect II tube pass 82 The pure water in the pool is transported to the upper sealed cavity of the II effect I tube pass 83, and the upper sealed cavity of the II effect I tube pass 83, the heat exchange tube 16 and the concentration tank are flushed;

After the second effect I tube pass 83 is rinsed, the clean water control valve 72 is opened, and the pure water in the concentration tank of the II effect I tube pass 83 is transported to the condensed water storage tank 34 for storage.

The cleaning process adopts the method of cleaning each tube process step by step. While the previous tube process is being cleaned, the subsequent tube process continues to carry out the concentration work without affecting each other. When the liquid is discharged, only II is left. Efficiency I tube 83 needs to be cleaned, which greatly shortens the concentration-cleaning rotation cycle and improves production efficiency. Moreover, cleaning during the concentration process can not only keep the concentrated tube side wet, and prevent dry wall of the heat exchange tubes 16 of the concentrated tube side; but also can generate secondary steam when pure water cleans the heat exchange tubes 16 , to ensure that the secondary steam volume of the isothermal concentration tower body 13 is uniform and stable during the entire concentration process, so that the centrifugal compressor 6 works stably and prevents the compressed secondary steam volume from being unstable and causing damage to the centrifugal compressor 6. damage.

The technical principle of the present invention has been described above with reference to the specific embodiments. These descriptions are only for explaining the principle of the present invention, and should not be construed as limiting the protection scope of the present invention in any way. Based on the explanations herein, those skilled in the art can think of other specific embodiments of the present invention without creative efforts, and these methods will all fall within the protection scope of the present invention.

Claims (10)

1. An isothermal double-effect concentrating unit, comprising a double-effect concentrating system and a secondary vapor recompression system, the double-effect concentrating system and the secondary vapor recompressing system are connected, and the double-effect concentrating system sequentially includes from upstream to downstream The raw material tank, the preheating unit, the isothermal concentration tower body, the one-body double-effect heater and the ointment collecting tank are characterized in that: The isothermal concentration tower body is sleeved on the outside of the same-body double-effect heater, and a secondary steam collecting cavity is formed between the isothermal concentration tower body and the same-body double-effect heater; The one-body double-effect heater includes a main casing, an upper head, an upper tube plate, a lower tube plate and a plurality of heat exchange tubes, the upper tube plate is arranged on the upper end of the main casing, and the The lower end is provided with the lower tube plate, and the upper end of the main shell is sealed with the upper head; the upper tube plate and the lower tube plate are distributed with a plurality of installation holes for heat exchange tubes, and the plurality of heat exchange tubes pass through the The heat pipe mounting holes are vertically installed in an array between the upper tube sheet and the lower tube sheet; It also includes an upper sealing baffle and a lower sealing baffle, the upper sealing baffle is arranged in the inner cavity of the upper sealing head and divides the inner cavity of the upper sealing head into three upper sealing cavities, and the lower sealing baffle is arranged in the inner cavity of the upper sealing head. The bottom of the isothermal concentration tower body is divided into three concentration pools, and the double-effect heater of the same body is arranged on the top of the lower sealing baffle; Divide the tube process of the same body double effect heater into I effect I tube process, I effect II tube process and II effect I tube process; The upper sealing chambers of the I effect I tube pass and the I effect II tube pass are all provided with water distributors, the I effect I tube pass and the I effect II tube pass are falling film concentration modules, and the II effect I tube pass Concentrate modules for forced circulation. 2. The isothermal double-effect concentrating unit according to claim 1 is characterized in that: the upper sealing cavity of the I-effect I tube pass is communicated with the preheating unit through a pipeline, and the concentration pool of the I-effect I tube pass is connected by a pipeline It is communicated with the upper sealing cavity of the I effect II tube pass, the concentration pool of the I effect II tube pass is communicated with the upper sealing cavity of the II effect I tube pass through the pipeline, and the concentration pool of the II effect I tube pass passes through the pipeline and the receiver. Paste tank is connected. 3. The isothermal double-effect concentrating unit according to claim 1, wherein the water distributor comprises a liquid storage tank and a liquid inlet pipe, the liquid inlet pipe is communicated with the liquid storage tank, and the liquid inlet pipe The sealing end of the liquid storage tank extends toward the interior of the liquid storage tank, and a section of the liquid inlet pipe located in the liquid storage tank is provided with a plurality of liquid inlet holes; The bottom of the liquid storage tank is provided with a plurality of liquid distribution branch pipes, the liquid distribution branch pipes and the heat exchange pipes are aligned one by one, and the liquid distribution branch pipes are inserted into the corresponding heat exchange pipes; The bottom of the liquid distribution branch pipe is sealed, and the side wall of the liquid distribution branch pipe is provided with a plurality of liquid spray holes. 4. The isothermal double-effect concentrating unit according to claim 3, wherein the double-effect concentrating system further comprises a falling film circulating pump, a falling film regulating valve, the first forced circulating pump, the first forced circulating regulating valve and the Outlet pump; The liquid inlet of the falling film circulating pump is communicated with the concentration tank of the I effect I tube pass through a pipeline, and the liquid outlet of the falling film circulating pump is connected to the liquid inlet pipe of the water distributor located in the I effect II tube pass through the pipeline. The open end of the falling film regulating valve is connected with the concentrating tank of the I effect II tube side through a pipeline, and the liquid outlet of the falling film regulating valve is connected with the liquid inlet of the falling film circulating pump through a pipeline ; The liquid inlet of the first forced circulation pump is communicated with the concentration pool of the I effect II tube side through the pipeline, and the liquid outlet of the first forced circulation pump is communicated with the upper sealing cavity of the II effect I tube side through the pipeline, so The liquid inlet of the first forced circulation regulating valve is communicated with the concentration pool of the II-effect I tube side through a pipeline, and the liquid outlet of the first forced circulation regulating valve is communicated with the liquid inlet of the first forced circulation pump through a pipeline; The liquid inlet of the liquid outlet pump is communicated with the concentration tank of the II-effect I tube side through a pipeline, and the liquid outlet of the liquid outlet pump is communicated with the ointment collection tank through a pipeline. 5. The isothermal double-effect concentrating unit according to claim 4, wherein the double-effect concentrating system further comprises a falling-film frequency converter and a density meter, the falling-film frequency converter and the falling-film circulating pump are electrically connected, so The falling film frequency converter controls the speed of the falling film circulating pump; The detection end of the density meter is communicated with the concentration pool of the II effect I tube pass. 6. The isothermal double-effect concentrating unit according to claim 4, wherein the secondary steam recompression system further comprises a centrifugal compressor, a heating steam output pipe and a secondary steam input pipe, and the secondary steam One end of the input pipe is communicated with the input port of the centrifugal compressor, the other end of the secondary steam input pipe is communicated with the isothermal concentration tower body, and one end of the heated steam output pipe is communicated with the output port of the centrifugal compressor; It also includes a heating outer casing, the heating outer casing is arranged around the outer side of the upper part of the main casing to form a heating and sealing cavity, and the side wall of the main casing corresponding to the heating outer casing is provided with a plurality of two a secondary steam input through hole, and the other end of the heating steam output pipe is communicated with the heating outer shell; The middle part of the lower sealing baffle is provided with a bearing convex surface, and the one-body double-effect heater is arranged on the bearing convex surface. 7. The isothermal double-effect concentrating unit according to claim 6, wherein the preheating unit comprises a liquid feed pump, a raw material regulating valve, an output three-way control valve, a primary heat exchanger, and a secondary heat exchanger , condensed water storage tank, water purification tank, input three-way control valve and water purification control valve, the liquid inlet of the raw material regulating valve is communicated with the raw material tank through the pipeline, and the liquid outlet of the raw material regulating valve is connected through the pipeline and the inlet. The liquid inlet of the liquid pump is connected, the liquid outlet of the liquid inlet pump is connected with the liquid inlet of the output three-way control valve, and the first liquid outlet of the output three-way control valve passes through the pipeline and is located in the I effect I pipe. The open end of the liquid inlet pipe of the water distributor of the process is connected; The first liquid inlet of the input three-way control valve is communicated with the water purification tank through a pipeline, and the second liquid inlet of the input three-way control valve is communicated with the liquid outlet of the raw material regulating valve through a pipeline. The liquid outlet of the control valve is communicated with the liquid inlet of the liquid inlet pump through a pipeline; the liquid inlet of the water purification control valve is communicated with the concentration pool of the II-effect I tube side through a pipeline, and the outlet of the said purification control valve is connected. The liquid port is communicated with the condensed water storage tank through a pipeline; The one-body double-effect heater also includes a condensed water output pipe, one end of the condensed water output pipe is communicated with the main shell, and the other end of the condensed water output pipe is communicated with the working medium inlet of the primary heat exchanger, so the The working medium outlet of the primary heat exchanger is communicated with the condensed water storage tank through a pipeline, and the liquid inlet of the primary heat exchanger is communicated with the second liquid outlet of the output three-way control valve through a pipeline. The liquid inlet of the heat exchanger is communicated with the liquid outlet of the primary heat exchanger through a pipeline, and the liquid outlet of the secondary heat exchanger is communicated with the first liquid outlet of the output three-way control valve through a pipeline, The working medium inlet of the secondary heat exchanger is connected to a boiler through a pipeline, and the working medium outlet of the secondary heat exchanger is connected to a steam discharge pipe. 8. The isothermal double-effect concentrating unit according to claim 7, characterized in that: the one-body double-effect heater further comprises a non-condensable gas output pipe and a plurality of shut-off plates, the non-condensable gas output pipe and the main casing connected; A plurality of the blocking plates are arranged inside the main casing, and one side of the plurality of blocking plates is connected with the inner wall of the main casing, and the other sides of the plurality of blocking plates are formed between the main casing and the main casing. The gaps are arranged in an S shape. 9. according to the concentration method of the isothermal double-effect concentration unit described in any one of claim 1 to 8, it is characterized in that, comprise solution concentration process and secondary steam circulation process: The solution concentration process includes the following steps: Step A, after the low-temperature solution stored in the raw material tank is heated into a high-temperature solution by a preheating unit, it enters the first-effect I tube process of the same body double-effect heater; Step B, after the high temperature solution enters the upper sealing cavity of the I effect I tube side, the water distributor of the I effect I tube side evenly distributes the high temperature solution to each heat exchange tube of the I effect I tube side. Under the action of gravity, the high-temperature solution flows to the concentration tank of the I effect I tube side in a film shape for falling film concentration; Step C, the falling film circulating pump extracts the high temperature solution in the concentration tank of the I effect I tube pass and transports it to the upper sealing cavity of the I effect II tube pass, and the water distributor of the I effect II tube pass evenly distributes the high temperature solution. In each heat exchange tube of the I effect II tube pass, the high temperature solution in the heat exchange tube flows to the concentration pool of the I effect II tube pass in a film form under the action of gravity, and performs falling film concentration; When the high temperature solution in the concentration pool of the I effect II tube pass does not reach the required concentration of falling film, the falling film regulating valve is opened, and the falling film circulating pump will transport the high temperature solution in the concentration pool of the I effect II tube pass back to the I effect II tube Falling film concentration is carried out in the upper sealing chamber of the tube process until the high temperature solution in the concentration tank of the I effect II tube process reaches the required concentration of the falling film; Step D, the first forced circulation pump transports the high temperature solution that reaches the required concentration of falling film to the upper sealing cavity of the II effect I tube side, and then performs forced circulation concentration in the heat exchange tube of the II effect I tube side, and the concentrated high temperature solution is obtained. The liquid is concentrated in the concentration tank of the II effect I tube; When the high-temperature solution in the concentration tank of the II effect I tube pass does not reach the required concentration, the first forced circulation regulating valve is opened, and the first forced circulation pump transports the high temperature solution in the II effect I tube pass concentration tank back to the II effect The upper sealing chamber of the I tube side is forced to circulate and concentrate until the high temperature solution in the concentration pool of the II effect I tube side reaches the required concentration of the liquid; Step E, the liquid outlet pump transports the high temperature solution that reaches the required concentration of the liquid to the ointment collection tank for storage; The secondary steam cycle process includes: First, the secondary steam in the isothermal concentration tower enters the centrifugal compressor through the secondary steam input pipe for compression and heating, and then enters the main casing through the heating steam output pipe to exchange heat with the heat exchange pipe in the main casing; Then, the secondary steam after heat exchange is condensed into liquid, which is transported to the condensed water storage tank through the condensed water output pipe, and the non-condensable gas is discharged through the non-condensable gas output pipe. 10. concentration method according to claim 9, is characterized in that, also comprises cleaning process: When the high-temperature solution is completely transported from the I effect I tube pass to the I effect II tube pass, that is, when there is no high temperature solution in the concentration pool of the I effect I tube pass, the pure water stored in the water purification tank is transported to the upper part of the I effect I tube pass. Sealing cavity, flushing the upper sealing cavity, heat exchange tube and concentration tank of I effect I tube side; When the high temperature solution is completely transported from the I effect II tube pass to the II effect I tube pass, that is, when there is no high temperature solution in the concentration tank of the I effect II tube pass, the falling film circulating pump will extract the pure water in the concentration pool of the I effect I tube pass. The water is transported to the upper sealing chamber of the I effect II tube side, and the upper sealing chamber, the heat exchange tube and the concentration tank of the I effect II tube side are flushed; When the high-temperature solution is completely transported from the II effect I tube pass to the cream collecting tank, that is, when there is no high temperature solution in the concentration tank of the II effect I tube pass, the first forced circulating pump will extract the pure water in the concentration tank of the I effect II tube pass It is transported to the upper sealing cavity of the II effect I tube pass, and the upper sealing cavity, the heat exchange tube and the concentration tank of the II effect I tube pass are flushed; After the second effect I tube pass is flushed, the clean water control valve is opened, and the pure water in the concentration tank of the II effect I tube pass is transported to the condensed water storage tank for storage.

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