CN104031657B - A kind of Novel rotary gas retort - Google Patents

Abstract

The invention discloses a novel rotary dry distillation furnace, which comprises a medium-temperature flue gas generating device, a furnace (2), a distribution plate (3), a medium-temperature flue gas heating zone (4), a flue gas partition (10), and an upper dynamic sealing ring (13), lower dynamic sealing ring (12), medium temperature flue gas inlet pipe (8), medium temperature flue gas inlet (A), low temperature flue gas discharge pipe (14), low temperature flue gas outlet (B), material inlet, drive The wheel (7), the induced draft fan, and the medium-temperature flue gas generating device can be regenerative type medium-temperature flue gas generating devices. The novel rotary dry distillation furnace provided by the invention has the advantages of uniform heating of materials, low investment cost, high thermal efficiency, good dry distillation effect, simple equipment operation, safe and reliable operation, and the like.

Description

A New Rotary Distillation Furnace

technical field

The invention relates to the field of dry distillation and provides a novel rotary dry distillation furnace.

Background technique

Dry distillation technology is a process in which materials are heated and decomposed under air-isolated conditions to produce coke (or semi-coke), tar, solution, dry distillation gas and other products. Dry distillation technology has been widely used in the utilization and development of conventional resources, waste treatment and the development of new energy, especially bio-energy. There are many methods and types of dry distillation. According to the heating method, there are external heat type, internal heat type and internal and external heat combination type; according to the shape of the material, there are three types: block material, type material and powder material; There are two types of carrier and solid heat carrier; according to the moving state of the material, it is divided into fixed bed, moving bed, fluidized bed, entrained flow bed and rotary retort furnace.

Chinese patent 201110200854.0 discloses a method for pyrolyzing materials using a regenerative rotating bed. Using this method, the material needs to be crushed into particles of 10mm to 100mm. The crushed material is distributed into the rotary bed through the distribution device, and is heated to 400-700°C under the action of the regenerative radiant tube without air, and is pyrolyzed to generate solid products and oil-gas mixture. The whole process takes 30-120 minutes. The solid product is cooled and sent to the finished product silo. After the oil and gas mixture is separated from the oil and gas, the product tar and dry distillation gas are obtained. But this method has the following disadvantages:

The regenerative rotary bed adopts the heating pyrolysis method. In this method, the radiant tube in the regenerative rotary bed goes around the rotary bed and is arranged on the top or bottom of the furnace. The material is pyrolyzed by radiation heating, and the heat transfer effect is poor. The material in the middle and lower layer is difficult to pyrolyze, and the thickness of the cloth is limited, thereby reducing the processing capacity of a single furnace. In order to improve its processing capacity, it is necessary to increase the number of radiant tubes or increase the temperature of radiant tubes. A single furnace needs to be equipped with at least a dozen radiant tubes, and as many as hundreds. The heat generated by the radiant tube is transferred to the surroundings, and the material is located on the lower or upper side of the radiant tube and can only obtain part of the radiant heat. On the other hand, each radiant tube requires an independent control system, which is relatively complex and increases the probability of equipment failure during operation. And because the radiant tube is arranged inside the furnace, once the radiant tube breaks abnormally during operation, the mixed gas in the radiant tube will come into contact with the retort gas in the furnace, which will pose a safety hazard. In order to improve the processing capacity of the rotary bed, a number of high-temperature oil-gas circulation fans are added to the rotary bed in this technology to enhance heat conduction and heat convection and speed up the pyrolysis rate. However, after adding high-temperature oil-gas circulation fans, during the pyrolysis process of materials, some High-temperature oil gas and dust adhere to the high-temperature fan pipes and fan blades. After long-term operation, it is easy to cause pipe blockage and affect the balance of fan blades. In serious cases, regular cleaning is required, which increases the workload and reduces the annual operation time of the equipment. . At the same time, due to the operation of the circulating fan, the turbulence of the air flow is strengthened, and the solid fine particles enter the oil-gas cooling system of the rear stage along with the oil gas, which increases the dust content in the oil gas of the rear stage. Moreover, the high-temperature oil-gas circulation fan has high investment costs and poor on-site application effect. In addition, during the radiation heating process, because the radiant tube is a certain distance from the material, usually between 500mm-1200mm, the heat conduction rate is significantly reduced, the temperature gradient between the material layers is significantly increased, and the pyrolysis uniformity is poor.

Contents of the invention

The technical problem to be solved by the present invention is to aim at the defects of the above-mentioned prior art, and to provide a rotary pyrolysis and retort material that makes the material heated evenly, has low investment cost, high thermal efficiency, good retort effect, simple equipment operation, and safe and reliable operation. The dry distillation furnace is suitable for the medium-temperature flue gas generating device of the rotary dry distillation furnace and the flue gas heating area adopting a labyrinth design. The invention can also reduce the volume in the furnace, shorten the residence time of the oil gas produced in the pyrolysis process in the furnace, and improve the quality of the oil. After adopting the present invention to replace the traditional rotary retort furnace, the high-temperature blower can be eliminated, the solid particles in the oil gas after pyrolysis are greatly reduced, the quality of the obtained oil gas is good, and the particle content in the obtained pyrolysis gas is not higher than 20mg/Nm ³ , thus directly Reduce the emission of solid pollutants in flue gas after combustion.

In order to solve the above-mentioned technical problems, the present invention adopts a medium-temperature flue gas generating device, which replaces the original radiant tube heating method by introducing medium-temperature flue gas from the bottom of the distribution plate for heating. Distribute the prepared materials evenly on the distribution board, heat up, and the materials are gradually pyrolyzed in the closed space. The temperature of the rotary dry distillation furnace is controlled at 500°C-750°C, and the pressure is 0-10kpa (gauge pressure). The residence time of the pyrolysis raw material in the rotary carbonization furnace is controlled within 2 hours. Under the heating of the medium-temperature flue gas inside the heating zone at the bottom of the distribution plate, the material in the lower layer is heated up to reach the pyrolysis temperature first, and then gradually pyrolyzes to produce medium-temperature oil gas. At the same time, under the dual effects of heat transfer, heat conduction and medium-temperature oil and gas release of heat between the materials, the temperature of the upper and middle layers rises rapidly. With the operation of the rotary retort furnace, the material is continuously pyrolyzed to produce a large amount of oil and gas. Under the action of the induced draft fan at the back section of the oil and gas pipeline, the oil and gas are drawn out from the retort furnace and enter the cooling system.

The medium-temperature flue gas generated by the medium-temperature flue gas generator enters the pipeline through the medium-temperature flue gas, enters the heating zone at the bottom of the distribution plate through the medium-temperature flue gas inlet, and the low-temperature flue gas generated after exchanging heat with the material passes through the low-temperature flue gas The discharge pipe enters the medium temperature flue gas generating device. The middle-temperature flue gas inlet and the low-temperature flue gas outlet are separated by a flue gas partition, so that the flue gas entering and leaving the heating zone is completely isolated. The medium-temperature flue gas inlet and low-temperature flue gas outlet can move together with the distribution plate by adopting the upper and lower dynamic sealing rings, while the medium-temperature flue gas inlet pipe and low-temperature flue gas discharge pipe connected to the middle-temperature flue gas inlet and low-temperature flue gas outlet are fixed. . The medium-temperature flue gas inlet pipe, the low-temperature flue gas discharge pipe, and the inner side of the medium-temperature flue gas generating device are all made of insulating materials, so that the medium-temperature flue gas is completely isolated from the outside world and the retort furnace, and reduces heat loss. The inner and outer water seals are used between the distribution plate and the furnace to isolate the entire furnace from the atmosphere. After adopting this heating method, the medium-temperature flue gas provides static heat to the material, the material is heated evenly, the pyrolysis rate is more than 10% higher than the radiation heating rate, and the pyrolysis time is greatly reduced.

As an improvement of the present invention, the bottom of the distribution board can be divided into two or more heating zones, and an appropriate amount of partitions are evenly distributed in each heating zone, so that the distribution board is evenly heated. The baffle can be straight or curved, and the least resistance is the best when the flue gas flows in the heating zone. The fabric board can be made of stainless steel or other materials with high temperature resistance and good thermal conductivity. The cloth plate can be made of steel plate or corrugated plate. All of these can correspondingly solve the technical problems to be solved by the present invention.

The flue gas heating area can also adopt a labyrinth design, so that the cloth plate is evenly heated.

The central rotation axis of the flue gas pipe is defined as the flue gas pipe between the upper and lower dynamic sealing rings. The medium-temperature flue gas can enter the rotary retort furnace from one end of the central rotating shaft of the flue gas pipe, and the low-temperature flue gas leaves from the other end of the central rotating shaft of the flue gas pipe. Rotary retort furnace, through the four-way reversing valve, can control the reversing between the entry of medium-temperature flue gas and the discharge of low-temperature flue gas at a certain frequency, so as to ensure that the materials on the entire distribution plate are heated evenly.

In addition, the medium-temperature flue gas generating device used in the present invention can be a regenerative medium-temperature flue gas generating device, and the entry of medium-temperature flue gas and the discharge of low-temperature flue gas can be reversed along with the reversing of the flue gas of the regenerative medium-temperature flue gas generating device. .

The invention can also reduce the volume in the furnace, shorten the residence time of the oil gas produced in the pyrolysis process in the furnace, and improve the quality of the oil. After adopting the present invention to replace the traditional rotary retort furnace, the high-temperature blower can be eliminated, the solid particles in the oil gas after pyrolysis are greatly reduced, the quality of the obtained oil gas is good, and the particle content in the obtained pyrolysis gas is not higher than 20mg/Nm ³ , thus directly Reduce the emission of solid pollutants in flue gas after combustion.

Description of drawings

The specific embodiment of the present invention will be further described below in conjunction with accompanying drawing:

Figure 1 is a sectional view of a rotary retort furnace.

Among them: 1. furnace top; 2. furnace; 3. distribution board; 4. medium temperature flue gas heating zone; 5. heat insulation layer; 6. sealing groove; 7. driving wheel; 8. medium temperature flue gas pipe; 9. heat preservation layer; 10, flue gas partition; 11, supporting beam; 12, lower dynamic sealing ring; 13, upper dynamic sealing ring; 14, low temperature flue gas pipe; A/B, medium temperature flue gas inlet/low temperature flue gas outlet

Figure 2 is an oblique view of the flow direction of medium-temperature flue gas in the heating zone when the heating zone at the bottom of the distribution plate is divided into four heating zones as an example

Among them: 1. Medium-temperature flue gas inlet in the first heating area of the distribution plate; 2. Low-temperature flue gas outlet in the first heating area of the distribution plate; 3. Low-temperature flue gas outlet in the third heating area of the distribution plate; 4. Inside the distribution plate; 5. Fourth heating of the distribution plate 6. Medium-temperature flue gas inlet in the second area of cloth plate heating; 7. Low-temperature flue gas outlet in the third area of cloth plate heating; 8. Flue gas pipeline; 9. Inlet of middle-temperature gas in the third area of cloth plate heating; 10. Outer side of the distribution board; 11. Low-temperature flue gas outlet of the second heating area of the distribution board;

Figure 3 is a top view of the flow of flue gas in the heating zone

Among them: 1. Inner side of the distribution board; 2. Outer side of the distribution board; 3. Low temperature flue gas outlet; 4. Baffle; 5. Partition; 6. Flue gas flow direction; 7. Medium temperature flue gas inlet;

Detailed ways

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described further:

It can be seen from the preferred specific embodiments of the present invention shown in Fig. 1 to Fig. 3 that before the material enters the carbonization furnace, it needs to be pretreated.

This preprocessing includes one or more of the following:

a) Raw material crushing: crush the above raw materials according to the requirements of pyrolysis until the particle size is less than 100mm.

b) Drying of raw materials: Dry the crushed raw materials according to the pyrolysis requirements, and the drying temperature is 30°C-220°C.

After the material is pretreated, it is fed into the inlet bin of the distribution plate through the upper feed port of the rotary retort furnace. Under the action of the distribution baffle, the material is uniformly distributed on the distribution plate, and the thickness of the material layer is less than 400mm. During the whole operation process, the furnace top wall is fixed, and the material moves in a circular motion together with the distribution plate under the action of the driving wheel at the bottom of the furnace, and the material is stationary relative to the distribution plate. The upper surface of the flue gas heating plate is directly used as a distribution plate to provide heat for the material, and the lower plate is made of heat-insulating material to effectively prevent heat loss. The fabric board is made of stainless steel.

Before the whole system is officially put into operation, a certain amount of nitrogen should be introduced to replace the inside of the whole system 2-3 times, the air in the system should be exhausted, and then the air release valve of the system should be closed to ensure that the whole system has good airtightness. During the whole pyrolysis process, the system is carried out under the condition of oxygen isolation.

Distribute the prepared materials evenly on the distribution board, heat up, and the materials are gradually pyrolyzed in the closed space. The temperature of the rotary dry distillation furnace is controlled at 500°C-750°C, and the pressure is 0-10kpa (gauge pressure). The residence time of the pyrolysis raw material in the rotary carbonization furnace is controlled within 2 hours. Under the heating of the medium-temperature flue gas inside the heating zone at the bottom of the distribution plate, the material in the lower layer is heated up to reach the pyrolysis temperature first, and then gradually pyrolyzes to produce medium-temperature oil gas. At the same time, under the dual effects of heat transfer and heat conduction between materials and the release of medium-temperature oil and gas, the materials in the middle and upper layers heat up rapidly. According to the temperature rise of the material, with the operation of the rotary retort furnace, the material is continuously pyrolyzed to produce a large amount of oil gas. Under the action of the induced draft fan in the rear section of the oil and gas pipeline, the oil gas is drawn out from the retort furnace and enters the cooling system.

The medium-temperature flue gas generated by the medium-temperature flue gas generating device enters the medium-temperature flue gas into the pipeline 8, and then enters the heating zone 4 at the bottom of the distribution plate through the medium-temperature flue gas inlet A. As shown in Figure 2, the heating area at the bottom of the cloth plate is divided into four isolated areas, and each area has a medium-temperature flue gas inlet and a low-temperature flue gas outlet. If it runs for a long time, the temperature of the distribution plate near the entrance of the medium-temperature flue gas will be high, and the temperature of the distribution plate near the outlet of the low-temperature flue gas will be low, resulting in uneven heating of the entire distribution plate. Therefore, after the entry of medium-temperature flue gas and the discharge of low-temperature flue gas are reversed with the direction of the flue gas of the medium-temperature flue gas generating device, the entrance of medium-temperature flue gas is reversed to the outlet of low-temperature flue gas. At the same time, the outlet of low-temperature flue gas is switched to the inlet of medium-temperature flue gas, and the temperature of the distribution board with low temperature will rise, ensuring that the entire distribution board is heated evenly, and the pyrolysis effect of the material on the distribution board is the best. As shown in Figure 1, the medium-temperature flue gas enters the heating zone 4 through the medium-temperature flue gas inlet A, and the low-temperature flue gas that exchanges heat with the material enters the low-temperature flue gas discharge pipe 14 through the low-temperature flue gas outlet B. Enter the medium temperature flue gas generating device. The middle-temperature flue gas inlet A and the low-temperature flue gas outlet B in Fig. 1 are separated by upper and lower middle-temperature flue gas partitions 10, so that the flue gas entering and leaving the heating zone is completely isolated. By adopting the upper and lower dynamic sealing rings, the medium-temperature flue gas inlet A and the low-temperature flue gas outlet B can move together with the distribution plate, and the medium-temperature flue gas connected to the medium-temperature flue gas inlet A and the low-temperature flue gas outlet B pipes enter the pipe 8 and the low-temperature flue gas Gas discharge pipe 14 is fixed. The medium-temperature flue gas inlet pipe 8, the low-temperature flue gas discharge pipe 14 and the inner side of the medium-temperature flue gas generating device adopt thermal insulation materials. An appropriate amount of baffles are evenly distributed on each heating zone at the bottom of the distribution board, so that the distribution board is evenly heated. The inner and outer water seals are used between the distribution plate and the furnace to isolate the entire furnace from the atmosphere.

Fig. 3 shows a top view of the flue gas flow direction in the rotary carbonization furnace. For the sake of simplicity, the flow direction of the flue gas flow in the rotary carbonization furnace is divided into two areas for description. The flue gas enters the rotary carbonization furnace from the medium-temperature flue gas inlet pipe 8, and forms low-temperature flue gas through the rotary carbonization furnace at the bottom of the furnace according to the flue gas flow direction shown in 6, and then exits the rotary carbonization furnace from the low-temperature flue gas discharge pipe 14, and the medium-temperature flue gas enters the rotary carbonization furnace. The pipe 8 is separated from the low-temperature flue gas discharge pipe 14 by a partition 10 . The temperature of medium-temperature flue gas entering the rotary retort furnace is controlled at 200°C to 1000°C, and the temperature of flue gas leaving the rotary retort furnace is controlled at 120°C to 500°C. The entire heating zone is separated by a vertical partition, which can not only make the flue gas flow in a certain direction, but also support the furnace floor. The heating area of the rotary retort furnace is completely isolated from the material pyrolysis area, so that the flue gas is isolated from the pyrolysis gas.

After material dry distillation, the solid dry distillation product is discharged outward along the radial direction of the circular distribution plate under the action of the discharge screw, and the semi-coke or carbon black product is cooled and collected after spray quenching in the latter stage.

The resulting liquid product is stored in oil tanks and exported directly or through further processing. Part of the obtained gas product is used as a heat source for material pyrolysis, and the other part can be supplied externally or used as raw material gas for chemical synthesis.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention. For example: the bottom of the distribution board can be divided into two or more heating zones, each heating zone is evenly distributed with a proper amount of partitions, so that the distribution board is evenly heated. The baffle can be straight or curved, and the least resistance is the best when the flue gas flows in the heating zone. The fabric board can be made of stainless steel or other materials with high temperature resistance and good thermal conductivity. The cloth plate can be made of steel plate or corrugated plate. The flue gas heating area can also adopt a labyrinth design, so that the cloth plate is evenly heated. The central rotation axis of the flue gas pipe is defined as the flue gas pipe between the upper and lower dynamic sealing rings. The medium-temperature flue gas can enter the rotary retort furnace from one end of the central rotating shaft of the flue gas pipe, and the low-temperature flue gas leaves from the other end of the central rotating shaft of the flue gas pipe. Rotary retort furnace, through the four-way reversing valve, can control the reversing between the entry of medium-temperature flue gas and the discharge of low-temperature flue gas at a certain frequency, so as to ensure that the materials on the entire distribution plate are heated evenly. These can also solve the technical problems to be solved by the present invention to varying degrees.

Claims (4)

1. A new type of rotary retort furnace, including a medium-temperature flue gas generating device, a furnace (2), a distribution plate (3), a medium-temperature flue gas heating zone (4), a flue gas partition (10), and an upper dynamic sealing ring (13 ), lower dynamic sealing ring (12), medium temperature flue gas inlet pipe (8), medium temperature flue gas inlet (A), low temperature flue gas discharge pipe (14), low temperature flue gas outlet (B), material inlet, driving wheel ( 7), induced draft fan, four-way reversing valve, wherein the distribution board (3) is a functional material with high temperature resistance and good thermal conductivity, and the medium-temperature flue gas is directly passed into the inside of the distribution board (3), and after pretreatment The material is evenly distributed on the distribution plate (3) through the material inlet, and together with the distribution plate (3) under the action of the drive wheel (7) at the bottom of the furnace, it makes a circular motion together. The material is still relatively to the distribution plate (3), the temperature of the new rotary carbonization furnace is controlled at 500-750°C, and the gauge pressure is 0-10kpa, and the partition of the pretreated material in the rotary carbonization furnace is The oxygen pyrolysis time does not exceed two hours, and the medium-temperature flue gas generated by the medium-temperature flue gas generating device enters the pipeline (8) through the medium-temperature flue gas, and enters the medium-temperature flue gas through the medium-temperature flue gas inlet (A) to be heated In zone (4), the low-temperature flue gas generated after exchanging heat with the pretreated material passes through the low-temperature flue gas outlet (B), and is discharged into the medium-temperature flue gas through the low-temperature flue gas discharge pipe (14). Gas generating device, the middle-temperature flue gas inlet (A) and the low-temperature flue gas outlet (B) are separated by the flue gas partition (10), so that the flue gas entering and leaving the heating zone (4) Completely isolated, by using the movable upper dynamic sealing ring (13) and the lower dynamic sealing ring (12), the medium-temperature flue gas inlet (A) and the low-temperature flue gas outlet (B) follow the The distribution plate (3) moves together, and the medium-temperature flue gas inlet pipe (8) and the low-temperature flue gas discharge pipe ( 14) Fixed, through the four-way reversing valve, the reversing between the entry of medium-temperature flue gas and the discharge of low-temperature flue gas can be controlled at a certain frequency. The gas discharge pipe (14) and the inner side of the medium-temperature flue gas generating device are all made of insulating materials, so that the medium-temperature flue gas is completely isolated from the outside world and the new type of rotary carbonization furnace. Internal and external water seals are used between the furnaces to isolate the entire furnace of the novel rotary retort furnace from the atmosphere. A large amount of oil and gas produced by the pyrolysis of the pretreated material is drawn out under the action of the induced draft fan at the rear section of the oil and gas pipeline. 2. The novel rotary retort furnace according to claim 1, characterized in that: the medium-temperature flue gas generating device is a regenerative type medium-temperature flue gas generating device, the entry of medium-temperature flue gas and the discharge of low-temperature flue gas The flue gas of the gas generating device is reversed and reversed. 3. The novel rotary retort furnace according to any one of claims 1 to 2, characterized in that: the medium-temperature flue gas heating zone (4) adopts a labyrinth design, so that the distribution plate (3) is evenly heated. 4. The novel rotary retort furnace according to any one of claims 1 to 2, characterized in that: the bottom of the distribution plate (3) is divided into two or more medium-temperature flue gas heating zones (4), each A plurality of straight or curved partitions are evenly distributed in the medium-temperature flue gas heating zone (4), so that the distribution plate (3) is evenly heated.