CN202030668U - Waste treatment device for guiding pyrolytic gas of waste into cement decomposing furnace - Google Patents

Abstract

The utility model relates to waste treatment equipment for introducing the thermal decomposition gas of waste into a cement decomposition furnace, which is equipped with a cement firing furnace (30), a clinker cooler (40) for cooling The cement manufacturing equipment ( 200 ) of the calciner and the calciner ( 20 ) in which any one of the clinker coolers flows into the high-temperature exhaust gas is arranged adjacently. Among them, there are: a gasification furnace (1) for generating pyrolysis gas by gasifying waste, and a gas for sending the generated pyrolysis gas to the decomposition furnace (20) while keeping the carbon and ash contained in it. Delivery channel (6). Into the calciner (20), introduce the pyrolysis gas in a form that does not directly interfere with the mainstream of the waste gas flow from the firing furnace (30) or the clinker cooler (40), to prevent it from being scraped, so that It burns well. In this way, the existing cement manufacturing equipment can be effectively used, and the sanitary disposal of waste can be realized at low cost.

Description

Waste treatment equipment that introduces the pyrolysis gas of waste into the cement decomposition furnace

technical field

The utility model relates to a waste treatment equipment which is arranged adjacent to cement manufacturing equipment and utilizes a calciner to process waste hygienically, in particular to the effective utilization of the gas obtained by thermal decomposition of the waste.

Background technique

In recent years, with the improvement of living standards, there is an increasing need for sanitary treatment of garbage, and the increase in the amount of incineration is also predicted. The problem of very long construction period. In addition, it is necessary to evaluate the impact of the incinerator on the surrounding environment and disclose information to nearby residents, so it takes a long time to prepare before the start of construction. Furthermore, in Japan there is still a shortage of landfill sites for burying the ashes generated by incinerators. When establishing new waste disposal sites, installation of ash melting furnaces and establishment of ash recycling methods are necessary conditions.

On the other hand, in the cement industry, there has always been a tendency to use combustible waste as part of the fuel in order to reduce cement manufacturing costs, and proposed a plan to effectively utilize existing cement manufacturing equipment to sanitize waste.

However, in general, the calorific value of garbage is about 1000-3000 kcal/kg, which is lower than that of the fuel usually used in cement kilns (in the case of using coal, the calorific value of low-grade media is 5000-7000 kcal/kg). Therefore, when the pyrolysis gas from waste, for example, is sent to a cement kiln to be mixed and burnt together, the temperature in the kiln is relatively low, which may result in unsatisfactory fuel consumption.

Moreover, the water vapor contained in the pyrolysis gas from garbage may have adverse effects on the properties of cement clinker, and when the pyrolysis gas is burned in a cement kiln, hot spots may occur to form deposits.

In response to this, the inventors of the present application have developed a technique of supplying pyrolysis gas generated in a gasification furnace to a calciner or a firing furnace (kiln) of a cement manufacturing facility together with carbon and ash. Since the temperature of the calciner is lower than that of the kiln, about 900°C, the pyrolysis gas and carbon provided here are effectively used as fuel, and the ash also becomes part of the cement raw material.

In addition, high-temperature waste gas from the kiln flows into the decomposition furnace and blows up the cement raw material as a jet stream, so the pyrolysis gas supplied here is also blown up while burning, and is sent to the preheater together with water vapor and the like. Therefore, there is no need to worry about the deterioration of the properties of cement clinker and the problems of deposits in the kiln.

Utility model content

As mentioned above, the pyrolysis gas of waste has a relatively low calorific value and contains a relatively large amount of water vapor, so it cannot be said to be a fuel with good ignition performance and combustion performance. Therefore, in the case where only the pyrolysis gas is supplied to the calciner, there is a possibility that the pyrolysis gas is exhausted to the preheater without sufficient combustion along with the exhaust gas flow from the kiln.

Moreover, the decomposition furnace not only forms a structure in which high-temperature kiln exhaust gas can flow in, but also can flow in high-temperature exhaust gas (air) from the clinker cooler. In this case, once the pyrolysis gas catches up with the mainstream of cooler exhaust gas, it will Will skim the calciner to discharge without sufficient combustion.

In view of such circumstances, the purpose of this utility model is to improve the method of introducing pyrolysis gas into the decomposition furnace, so that the pyrolysis gas can be fully burned in the decomposition furnace. This enables efficient use of existing cement manufacturing equipment, reduces its operating costs, and enables hygienic disposal of waste.

In order to achieve the above object, the utility model is equipped with a cement firing furnace, a clinker cooler for cooling its fired products, and a decomposition furnace that flows high-temperature waste gas from any one of the firing furnace or the clinker cooler. The waste treatment equipment installed adjacent to the cement manufacturing equipment is the object. Furthermore, the waste treatment facility includes a gasification furnace for gasifying waste to generate pyrolysis gas, and transports the pyrolysis gas generated in the gasification furnace to the The gas conveying channel of the above-mentioned calciner, and the airflow of the thermally decomposed gas does not directly interfere with the main flow of the high-temperature exhaust gas flowing into the calciner from the kiln and the clinker cooler. A gas introduction unit that introduces pyrolysis gas into the decomposition furnace.

In such a structure, when waste is thermally decomposed in a gasifier of a waste treatment facility installed adjacent to a cement manufacturing facility to generate pyrolysis gas, the pyrolysis gas is kept intact while the carbon and ash contained in it are kept intact. Introduction of calciner for cement manufacturing equipment. In the calciner, high-temperature exhaust gas from the cement firing furnace and clinker cooler flows in, and the decarbonation reaction occurs while the cement raw material is being transported. If the pyrolysis gas is introduced downward, the pyrolysis gas will not pass over the calciner along with the waste gas flow. Therefore, the pyrolysis gas and carbon can be fully combusted in the calciner. Wherein, the waste treatment facility is configured such that the pyrolysis gas introduced into the decomposition furnace burns at a temperature of 850° C. or higher for at least 2 seconds or more when it stays in the decomposition furnace.

As an example, it is also possible that the calciner has a cylindrical peripheral wall and is disposed from one end to the other end in the direction of the cylinder axis to form the main flow of the exhaust gas flow from the kiln or the clinker cooler. Next, as a gas introduction unit, an introduction port is provided on the peripheral wall in a circumferential direction so that pyrolysis gas can be introduced rotatably around the cylinder axis. The pyrolysis gas introduced into the calciner in this way revolves around the main flow of the exhaust gas flow from the kiln without directly interfering with the main flow.

Usually, the peripheral wall of the calciner is configured to extend in the vertical direction so that the lower end thereof flows into the exhaust gas from the kiln or the clinker cooler to form a jet flow, which is directed upward. On the contrary, it is also possible to introduce the pyrolysis gas from the gas inlet at a predetermined angle of inclination downward relative to the horizontal plane. The predetermined inclination angle may be greater than 0 degrees and less than 40 degrees. It is not easy to follow the flow of exhaust gas. However, if the downward inclination is too large, the rotational component (horizontal velocity) of the pyrolysis gas flow will be small, so the inclination of the gas inlet with respect to the horizontal plane is at most less than 40 degrees, preferably less than 30 degrees.

And since the gas delivery channel from the gasifier to the side of the cement manufacturing equipment is basically horizontal, it is sufficient to at least incline downward at the gas inlet.

And the high flow velocity of the pyrolysis gas coming from the gas inlet has the effect of preventing the above-mentioned deposits from clogging, if the flow velocity is too high, the pressure loss at the gas inlet will increase, so it can also be 5～30m/ The flow rate of s is introduced into the pyrolysis gas.

However, in the case where the waste treatment equipment is arranged so that the exhaust gas from the burning furnace flows into the lower end of the surrounding wall of the decomposition furnace as in the above-mentioned prior art example, a device for introducing combustion air is usually provided at the lower part of the surrounding wall. The air inlet is used, however, combustion air may be introduced through the air inlet, and the air flow may be introduced so as to rotate in the same direction as the pyrolysis gas. By doing so, the swirling air flow of the pyrolysis gas and the swirling air flow of the combustion air strengthen each other, and the ignition performance and combustion performance of the pyrolysis gas are improved by sufficient mixing.

For this reason, it is preferable that the air inlet is also provided so as to extend downwardly at a predetermined angle with respect to the horizontal plane, and that the gas inlet be provided at a predetermined distance above the air inlet. The angle of inclination of the air inlet is substantially the same as the angle of inclination of the gas inlet, or may be slightly smaller than that.

Therefore, a swirling flow of combustion air is formed at an appropriate interval below the swirling flow of pyrolysis gas, and the exhaust flow flowing upward through the decomposition furnace first interferes with the swirling flow of combustion air. Interference between the main flow of exhaust gas and the swirling flow of pyrolysis gas is thus suppressed. Moreover, the combustion air swirl pushed up by the rising waste gas main flow pushes up the swirl of pyrolysis gas, and the two pass through the decomposition furnace to form a spiral swirl and mix with each other at the same time.

Also, the lower end of the above-mentioned calciner is connected to a pipe for circulating exhaust gas from the firing furnace, but the pipe usually extends downwards and bends in an L-shape to turn to the entrance of the firing furnace. Then, the exhaust gas flow that changes direction upward through the L-shaped duct is deflected toward the firing furnace side by the force from the inner wall surface of the duct, so the gas inlet can also be provided on the opposite side of the firing furnace side. on the wall.

In addition, generally used fuel supply ports such as fine carbon powder and heavy oil may be provided on the peripheral wall of the above-mentioned firing furnace near the gas introduction port. In this way, the fuel which is more ignitable than the pyrolysis gas is ignited first and becomes a kindling seed, and it is expected that the ignitability of the pyrolysis gas can be improved. In this case, it is also possible to reduce the supply of these fuels to avoid consumption of air by fuels such as fine toner and heavy oil.

Also, in the above-mentioned waste treatment equipment, if there are two or more gasification furnaces, two or more gas delivery channels are provided to transport the pyrolysis gas from each gasification furnace, and each gas delivery channel can be connected to Two or more gas introduction ports on the peripheral wall of the above-mentioned calciner communicate with each other. In this case, two or more gas introduction ports may be arranged at intervals in the circumferential direction.

If the view is changed, the utility model is a cement production with a cement firing furnace, a clinker cooler for cooling the fired product, and a calciner into which high-temperature waste gas from either the firing furnace or the clinker cooler flows. The equipment is equipped with a gas conveying passage for conveying the pyrolysis gas of the waste while keeping the carbon and ash contained in it, and introducing the pyrolysis gas into the decomposition furnace through the gas conveying passage, and making the pyrolysis gas A gas introduction unit that does not interfere with the main flow of exhaust gas from the above-mentioned kiln in the calciner. Adoption of such cement manufacturing equipment enables sanitary disposal of waste at low cost.

As described above, according to the present invention, it is possible to prevent the pyrolysis gas transported from the gasification furnace of the waste treatment equipment and introduced into the decomposition furnace of the cement manufacturing equipment from being accompanied by the waste gas flow from the kiln and the clinker cooler. Blown away, able to fully burn in the calciner. Therefore, it is possible to effectively utilize existing cement manufacturing facilities, and it is possible to realize sanitary treatment of waste while reducing running costs.

Description of drawings

Fig. 1 is a system diagram of a waste treatment facility and a cement manufacturing facility according to a first embodiment of the present invention.

Fig. 2A is a front view of a calciner showing a rotary kiln viewed from the right side in the above-mentioned cement manufacturing facility.

Fig. 2B is a right side view of the calciner viewed from the rotary kiln side.

Fig. 3A is an enlarged front view showing the lower portion of the calciner.

Fig. 3B is an enlarged right side view showing the lower part of the calciner.

Fig. 3C is an enlarged left side view showing the lower portion of the calciner.

Fig. 3D is an enlarged plan view showing the lower portion of the calciner, and a part of the calciner is omitted.

Fig. 4A is a CFD simulation diagram showing the kiln exhaust gas flow in the calciner.

Fig. 4B is a diagram corresponding to Fig. 4A showing the air flow for combustion.

FIG. 5A is a diagram corresponding to FIG. 3A showing a modified example in which two gas inlets are provided.

FIG. 5B is a view corresponding to FIG. 3B showing a modified example in which two gas inlets are provided.

FIG. 5C is a diagram corresponding to FIG. 3C showing a modified example in which two gas inlets are provided.

FIG. 5D is a diagram corresponding to FIG. 3D showing a modified example in which two gas inlets are provided.

Fig. 6 is a diagram corresponding to Fig. 1 in a second embodiment in which cooler exhaust gas flows into a decomposition furnace.

Fig. 7 is a graph showing the relationship between the inclination angle of the gas introduction port and the gas flow velocity in the horizontal direction.

8 is a graph showing the transition of the dimensionless standard deviation of the carbon monoxide concentration in the height direction from the pyrolysis gas inlet.

Symbol Description:

100 waste treatment equipment;

1 gasifier;

6 gas delivery pipeline (gas delivery channel);

200 cement manufacturing equipment;

10 hanging preheater;

20 calciner;

21 lower pipe;

23 side wall (cylindrical side wall);

24 inclined part;

25 air supply port;

26 fuel supply port;

27 Gas inlet (gas inlet unit);

30 rotary kiln (firing furnace);

40 Air Quenching Cooler (clinker cooler). the

Detailed ways

The ideal embodiment of the present utility model will be described below with reference to the accompanying drawings. Fig. 1 is an overall system diagram of a waste treatment facility 100 and a cement manufacturing facility 200 provided adjacent thereto according to the first embodiment. The waste treatment facility 100 shown on the left side of the figure thermally decomposes waste in the gasification furnace 1, and the generated gas (pyrolysis gas) is mixed and burned in the cement firing process.

―Waste disposal facilities―

In the waste processing facility 100 , for example, general waste from households, industrial waste including waste plastics, etc., and waste including combustible objects are collected. These wastes are transported by land transportation etc., are thrown into the hopper 2a in the tank 2, and are crushed by the crusher which is not shown in figure. The crushed waste is conveyed by the crane 3, put into the conveying device 4 composed of a hopper, a conveyor belt, etc., and sent to the gasification furnace 1 by the operation of the conveying device 4.

As an example, the illustrated gasification furnace 1 is a fluidized bed type gasification furnace, and a fluidized sand (fluid medium) layer formed in the lower part of the furnace is fluidized by air. The air sent to the fluidized bed is sucked from the waste tank 2 by the blower 5 in the illustration, and supplied to the gasifier 1 by the supply line 5a. Therefore, the inside of the waste tank 2 is maintained at a negative pressure, and abnormal odors are less likely to leak to the outside. The temperature of the fluidized bed is usually around 500-600°C, and the waste is thermally decomposed while being dispersed under the action of the moving sand, and part of the combustion of the waste also promotes thermal decomposition.

Then, the pyrolysis gas of the waste is exhausted from the upper part of the gasification furnace 1 and sent to the cement manufacturing facility 200 through the gas delivery line 6 (gas delivery channel). In this pyrolysis gas, carbon and ash which are unburned components float as small particles, and are transported together with the pyrolysis gas. In addition, an open-close damper is provided in the middle of the gas delivery pipeline, and the damper can be closed when the waste gas treatment equipment 100 stops running.

―Cement Manufacturing Equipment―

The cement manufacturing facility 200 has a general NSP kiln in the illustration. After the cement raw material is preheated in the hanging preheater 10 as a preheater, it is heated to about 900°C in the calciner 20 (calcination), and it is carried out at a high temperature of about 1500°C in the rotary kiln 30 as the firing furnace. burnt. The fired product passed through the rotary kiln 30 is rapidly cooled in the air quenching cooler 40 to become granular cement clinker, and then sent to a refining process not shown in the figure.

The suspended preheater 10 has multi-stage swirlers 11 arranged side by side in the up and down direction in a zigzag shape. The cyclones 11 exchange heat with the high-temperature waste gas blown in from the next stage while conveying the cement raw material by the vortex airflow. The waste gas flow is as follows. High-temperature waste gas from the rotary kiln 30 (hereinafter simply referred to as "kiln waste gas") rises through the calciner 20 and is supplied to the cyclone 11 at the lowest stage. The kiln exhaust gas, as shown by the dotted line in the figure, rises step by step through the cyclone, reaches the uppermost cyclone 11, and flows out to the exhaust gas pipeline 50 from there.

As shown in the figure, a large-capacity induced draft fan 52 for inducing kiln exhaust gas to be sent out to the chimney 51 is installed on the exhaust gas pipeline 50, and a large-capacity induced draft fan 52 is installed on the front side of the induced draft fan 52, that is, the upstream side of the exhaust gas flow. Gas cooler 53 and dust collector 54 . The induced draft fan 52 has the function of guiding a large amount of waste gas from the rotary kiln 30 through the suspended preheater 10 and the decomposition furnace 20 , and also has the function of inducing the pyrolysis gas from the above-mentioned gasification furnace 1 .

On the other hand, in each cyclone 11 of the suspended preheater 10, after the heat exchange between the cement raw material and the high-temperature kiln exhaust gas as described above, as shown by the solid line in the figure, it falls downward, and the next stage of cyclone Flow device 11 moves. In this way, when the uppermost cyclone 11 passes through a plurality of cyclones 11 in sequence, the cement raw material is fully preheated, and is provided to the calciner 20 from the uppermost cyclone 11 of the lowermost stage.

The calciner 20 is arranged at the kiln rear portion of the rotary kiln 30 extending in the vertical direction. The details will be described below with reference to FIGS. 2 and 3 . Flow device 11 provides cement raw material to it. The lower part of the decomposition furnace 20 is supplied with pyrolysis gas and fine carbon powder from the above-mentioned gasification furnace, and high-temperature cooler exhaust gas from the air quenching cooler 40 is supplied as air for combustion.

The lower end of the calciner 20 is connected to an approximately L-shaped lower pipe 21, which is connected to the rotary kiln 30. The lower pipe 21 extends downward from the lower end of the calciner 20 and bends toward the rotary kiln 30 side. Extend roughly horizontally. High-temperature kiln exhaust gas is sent to the lower end of the calciner 20 through the lower duct 21 and is blown upward as a jet flow. The cement raw material is blown upwards with this kiln exhaust gas flow.

When blowing upward in this way and rising through the inside of the calciner 20, the cement raw material is heated to about 900° C., and 80% to 90% of the lime component undergoes a decarbonation reaction. Then through the upper pipe 22 connected to the uppermost part of the calciner 20, it is sent to the lowest stage cyclone of the hanging preheater 10. Here, the kiln exhaust gas is separated from the cement raw material and moves to the upper cyclone 11 , while the cement raw material falls from the lower end of the cyclone 11 and reaches the entrance of the rotary kiln 30 .

The rotary kiln 30 is formed by arranging a horizontally long cylindrical rotary kiln with a length of, for example, 70 to 100 m, inclined slightly downward from the entrance to the exit. The rotary kiln rotates slowly around its axis to convey the cement raw material to the outlet side. A combustion device 31 is arranged on the outlet side, and high-temperature combustion gas generated by combustion of coal, natural gas, heavy oil, etc. is ejected toward the inlet side. The cement raw material surrounded by combustion gas undergoes a chemical reaction (cement firing reaction), and part of it is fired to a semi-molten state.

The burnt cement product is quenched by cold air in the air quenching cooler 40 to form granular cement clinker. Then, after the cement clinker is stored in the clinker warehouse, gypsum is added to adjust the composition, and then it is ground and pulverized into fine powder (finishing process) (illustration and detailed description omitted). On the other hand, the cooler exhaust gas obtained from the burnt product with the heat raised to about 800° C. is supplied to the calciner 20 as combustion air as described above. That is, waste heat is recovered to raise the temperature of the combustion air in the decomposition furnace 20, thereby improving thermal efficiency.

―Structure of calciner―

Next, the structure of the calciner 20 of this embodiment, especially the structure capable of properly introducing pyrolysis gas and combustion air will be described in detail with reference to FIGS. 2A, 2B, and 3A to 3D. FIG. 2A is a front view of the calciner 20 viewed from the right side of the rotary kiln 30 , and FIG. 2B is a right side view of the calciner viewed from the rotary kiln 30 side. 3A to 3C are respectively enlarged front view, right side view, and left side view of the lower part of the calciner 20, and FIG. 3D is an enlarged top view of the lower part of the calciner 20, and a part of the calciner is omitted.

As shown in Figures 2A and 2B, the calciner 20 is a cylindrical shape extending up and down, and most of its upper end to the lower part is a side wall part 23 (cylindrical peripheral wall) with approximately the same diameter, and the lower part is connected to the narrower side wall below it. Inclined wall portion 24 . The upper end of the substantially L-shaped lower duct 21 is connected to the lower end of the inclined wall portion 24 . As described above, high-temperature kiln exhaust gas flows in from the rotary kiln 30 through the lower duct 21 as a jet flow, and is blown upward in the calciner 20 from the lower end thereof.

As shown by the gray arrows in FIG. 3A , the kiln exhaust gas flow circulating in the lower pipe 21 flows from the side (right side) of the rotary kiln 30 into the horizontal part of the roughly L-shaped lower pipe 21, and turns upward at the zigzag part. When the direction of the flow is changed in this way, due to the force received from the inner wall surface of the lower pipe 21, the main flow of the rising kiln exhaust gas passing through the lower part of the calciner 20 is biased towards the rotary kiln 30 (exaggerated in the figure).

Thereafter, the main flow of the kiln exhaust gas passes through the interior of the calciner 20 while gradually approaching the center while ascending, and is affected by the swirling flow of the combustion air to have a swirling component. Such kiln exhaust gas flows to the upper end of the calciner 20 while blowing the cement raw materials upwards, and flows from there to the upper pipe 22. After the upper pipe 22 extends upward, it bends to the opposite side of the lower pipe 21, and reaches the bottom of the lowermost pipe. Cyclone 11 (refer to FIG. 1 ).

The lower portion of the calciner 20 is supplied with fine carbon powder as a fuel and combustion air so that such a kiln exhaust gas flow appropriately interferes with each other and is moderately mixed and heated. That is, as enlargedly shown in FIGS. 3A to 3C , the inlet port 25 for combustion air is provided in a sloped wall portion 24 at the lower end of the calciner 20 in a state inclined downward with respect to the horizontal plane. The high-temperature cooler exhaust gas from the air quench cooler 40 as described above is supplied to the air inlet 25 .

The air inlet 25 is provided on the front side of the side wall portion 23 of the calciner 20 as shown on the front side of FIG. 20a (cylinder axis), but relative to it, it points to the circumferential direction of about 30-45 degrees. Therefore, the flow of combustion air introduced into the calciner 20 from the air inlet 25 rotates around the vertical axis 20 a along the inner periphery of the inclined wall portion 24 as shown by the white arrow in FIG. 3B .

In addition, the cross-sectional shape of the air inlet 25 is a trapezoidal shape in which the upper base is longer than the lower base in the illustration, and the oblique sides are inclined according to the inclinations of the corresponding inclined wall portions 24 . The inflow cross-sectional area of the air inlet 25 is larger than that of the fuel supply port 26 and the gas inlet 27 which will be described later, so the flow rate thereof is also larger. The swirling flow of the combustion air having a large flow rate interferes moderately with the main flow of the kiln exhaust gas from below. Furthermore, as shown in FIG. 4B , the airflow is upward while rotating, while the kiln exhaust gas flow is upwardly rotating as shown in FIG. 4A .

4A and 4B are CFD simulation diagrams. Viewed from the rotary kiln 30 side, the kiln exhaust gas flow and combustion air flow in the calciner 20 are respectively represented by streamline simulation. It can be seen from Fig. 4A that the main flow of kiln exhaust gas flowing into the calciner 20 from the lower end of the kiln exhaust gas presses the fuel air flow (indicated by a white arrow) introduced from the left air inlet 25, making it deflect to the right in the figure. , thereafter slowly hovering and ascending with a rotating component.

On the other hand, as can be seen from FIG. 4B , the combustion air flow from the air inlet 25 rotates on the inclined wall portion 24 at the lower end of the calciner 20 while turning upwards with the help of the kiln exhaust gas flow (shown by the gray arrow) from below. Push to flow upwards. A part of the combustion air flow rises sharply with the main flow of the kiln exhaust gas, but the other part of the air flow spirals upward around the main flow of the kiln exhaust gas.

At the lowermost portion of the side wall portion 23 of the calciner 20, a fuel supply port 26 is provided so as to be able to mix with such an upward air flow while spiraling. The fuel supplied to the fuel supply port 26 is, for example, fine carbon powder, natural gas, or heavy oil. That's it. When natural gas or heavy oil is used as fuel, it may be injected from the fuel supply port 26 at a predetermined pressure.

As shown in FIGS. 3A to 3C , the two fuel supply ports 26 extend substantially horizontally on the front side and the back side of the side wall portion 23 . Also, as can be seen from FIG. 3D , the two fuel supply ports 26 are arranged in parallel on one side of the rotary kiln 30 and on the opposite side thereof. In other words, the two fuel supply ports 26 are provided on the same circumference with a phase shift of about 180 degrees from each other in the tangential direction of the circumference thereof so as to be able to blow fuel along the inner circumference of the side wall portion 23 , respectively.

Of the two fuel supply ports 26, a pyrolysis gas introduction port 27 is provided near the fuel supply port on the front side of the side wall portion 23, and a cement raw material input port 28 is provided above it. The gas introduction port 27 introduces the pyrolysis gas transported from the waste treatment facility 100 through the gas transport line 6 as described above into the decomposition furnace 20 in a predetermined state described below. Further, the cement raw material dropped from the cyclone 11 as described above is charged from the raw material inlet 28 .

As shown in FIGS. 3A to 3C , the gas inlets 27 are provided at predetermined intervals (for example, 2 to 6 m) above the air inlets 25 , and in the illustration, like the air inlets 25 , the pyrolysis gas is introduced downward relative to the horizontal plane. 3D, the gas inlet 27 is provided on the opposite side of the rotary kiln 30 on the side wall portion 23 of the calciner 20, and is directed in the circumferential direction so as to introduce pyrolysis gas along the inner circumference of the peripheral wall portion 23.

The pyrolysis gas introduced from the gas introduction port 27 flows along the inner periphery of the side wall portion 23 of the decomposition furnace 20, as shown by the black arrow in FIG. Rotate around the up and down axis 20a. In other words, the pyrolysis gas introduced from the gas inlet 27 swirls around the main flow of the kiln exhaust gas blown upward through the approximate center of the decomposition furnace 20 without directly interfering with the main flow.

Also, the swirling flow of combustion air with a larger flow rate is formed under the swirling flow of pyrolysis gas to suppress the interference of pyrolysis gas flow and kiln exhaust gas flow. That is to say, referring to Fig. 4A etc., as mentioned above, the main flow of kiln exhaust gas is pushed by the combustion air flow at the lower part of the calciner 20 to the opposite side of the air inlet 25, because the pyrolysis gas can be introduced to the main flow of kiln exhaust gas. The opposite side of the biased side.

And in this embodiment, with reference to Fig. 3A etc., as mentioned above, in the L-shaped lower pipe 21, the kiln exhaust gas main flow bent when passing through the lower part of the calciner 20 is deflected to the side of the rotary kiln 30, and the heat is decomposed. The gas is directed to the side opposite thereto, by means of which interference between the pyrolysis gas flow and the kiln exhaust gas flow can be suppressed.

In doing so, the mutual interference between the pyrolysis airflow and the kiln exhaust gas flow is suppressed. On the other hand, referring to FIG. Push up. When the combustion air flow pushed up in this way is sufficiently mixed with the pyrolysis airflow rotating side by side above it and rises, the pyrolysis gas can be fully combusted.

Also, the direction in which the pyrolysis gas is guided to the decomposition furnace 20 was changed for investigation. For example, as shown in FIG. 3D, taking one side _{of the rotary kiln 30 as a reference, the position and direction in the horizontal plane of the gas inlet 27 are represented by an angle θ 1 ;} The angle at which the horizontal plane slopes downward. Regarding the downward slope angle θ ₂ , since the gas delivery pipeline 6 from the gasifier 1 to the side of the rotary kiln 30 is basically horizontal, at least a downward slope (θ ₂ >0) at the gas inlet 27 is sufficient. Especially no problem. However, as shown in Figure 7, if θ ₂ is too large, the rotational component (horizontal velocity) of the pyrolysis airflow will be small, so θ ₂ can only be below 40 degrees at most, and ideally below 30 degrees.

Also, from the consideration of the mixing of pyrolysis gas and kiln exhaust gas or combustion air, it can be said that the flow velocity of the pyrolysis gas at the gas introduction port 27 is as high as possible, but if the flow velocity is high, the flow rate of the gas introduction port 27 The pressure loss becomes large, and is, for example, about 0.3 to 0.5 kPa when the gas flow velocity is 30 m/s. Therefore, in order not to increase the pressure loss at the gas introduction port 27 too much, the flow velocity of the pyrolysis gas is preferably 30 m/s or less. On the other hand, if the gas flow rate is slow, the rotational force of the gas is small, and the kiln exhaust gas flow is excessively accompanied. Therefore, the gas flow rate is preferably 5 m/s or more at the same level as the kiln exhaust gas flow rate.

Furthermore, FIG. 8 shows the results of a simulation performed to investigate the diffusion state of carbon monoxide in the pyrolysis gas in the calciner 20 . The horizontal axis of Fig. 8 represents the height calculated from the pyrolysis gas inlet, and the vertical axis represents the dimensionless standard deviation of the carbon monoxide concentration, that is to say, the smaller the dimensionless standard deviation of the carbon monoxide concentration, then it is considered that the calciner 20 internal heat The better the decomposition gases are mixed. The combustion of carbon monoxide was not considered in this simulation.

As can be seen from FIG. 8 , the dimensionless standard deviation of the carbon monoxide concentration is large near the pyrolysis gas inlet, and the mixing of the pyrolysis gas is insufficient. It can be seen that the dimensionless standard deviation of the carbon monoxide concentration becomes smaller as one goes upward from the pyrolysis gas inlet, and the mixing of the pyrolysis gas and air is promoted.

In addition, case A, case C1, case C2, case D1, and case D2 in the figure represent five cases in which the direction of introducing the pyrolysis gas into the decomposition furnace 20 is different. Specifically, it is convenient to make the direction in the horizontal plane of the gas inlet 27 as shown in Figure 3D take the rotary kiln 30 side as a reference to represent θ ₁ with three different angles and the gas inlet 27 relative to the horizontal plane as shown in Figure 3C There are 2 different angles for the angle θ ₂ of the inner downward slope. See the table below for more specific representations.

the Case A Case C1 Case C2 Case D1 Case D2 θ ₁ 70 degrees 95 degrees 95 degrees 135 degrees 135 degrees θ ₂ 20 degrees 20 degrees 25 degree 20 degrees 25 degree

If you look carefully at the curve of Fig. 8, it can be seen that in case A, that is, when _θ1 is 70 degrees, as the height from the pyrolysis gas inlet 27 becomes higher, compared with case C1, case C2, case D1, and case D2, the thermal Mixing of decomposition gas with air becomes poor. Then compare the situation C1 and C2, that is, the situation where _θ1 is 95 degrees, with the situation D1 and D2, that is, the situation where _θ1 is 135 degrees, and finally understand the thermal decomposition gas under the situation D1 and D2. Mixes slightly better with air. On the other hand, with regard to the inclination angle of the gas introduction port 27, no significant difference was observed between when _θ2 was 20 degrees and 25 degrees.

In the waste treatment facility 100 of the first embodiment described above, the pyrolysis gas generated from the waste in the gasification furnace 1 is sent to the cement production facility 200 through the transfer line 6 with the carbon and ash contents unchanged. , is introduced into the calciner 20. The high-temperature kiln waste gas from the rotary kiln 30 flows into the calciner 20 and forms a jet flow to blow upwards. However, when the pyrolysis gas is introduced, it does not directly interfere with the main flow of the kiln waste gas, so the pyrolysis gas and carbon are not scraped away. , can be fully burned in the calciner 20.

Especially in this embodiment, the pyrolysis gas is introduced from the gas inlet port 27 provided at the lower part of the peripheral wall portion 23 of the calciner 20 to revolve around the main flow of the kiln exhaust gas, and at the same time, a larger flow rate is formed below it for combustion. The swirling flow of the air, if it first interferes with the kiln exhaust gas flow from below, can reliably prevent the kiln exhaust gas flow from blowing away the pyrolysis gas.

Then, the combustion air whose temperature is raised by kiln exhaust gas is fully mixed with the pyrolysis gas rotating in parallel to improve its ignition performance and combustion performance, and then fuel such as fine carbon powder is supplied from the fuel supply port 26 provided near the gas introduction port 27. , to ignite it to burn it, which is expected to further improve the ignition performance of the pyrolysis gas as a kindling seed.

―Modification―

As described above, in the first embodiment, the pyrolysis gas and the combustion air are introduced into the side opposite to the side of the rotary kiln 30 on the peripheral wall portion 23 of the decomposition furnace 20. limited to one. If more than two gasification furnaces 1 are provided in the waste treatment facility 100 , the pyrolysis gas transported from each gasification furnace 1 can also be introduced into each decomposition furnace 20 by using each gas delivery pipeline 6 .

For example, a modified example in which two gas introduction ports 27 are provided in the calciner 20 is shown in FIGS. 5A to 5D . This modified example differs from the calciner 20 of the first embodiment only in the number and positions of the gas inlets 27, and is otherwise the same. As shown in FIGS. 5A to 5C , in the calciner 20 of the modified example, two gas inlets 27 are provided on the side of the rotary kiln 30 and on the opposite side, respectively, inclined downward with respect to the horizontal plane as in the first embodiment.

In addition, as shown in FIG. 5D , in a plan view, the two gas inlets 27 are directed in the circumferential direction, respectively guide the pyrolysis gas along the inner circumference of the side wall 23 , and are arranged in parallel with a phase difference of 180 degrees. That is to say, the two gas inlets 27 guide the pyrolysis gas on the same circumference to form the same swirl flow. In this way, the rotating component of the swirling flow is strengthened and the pyrolysis gas is guided to the separated parts as much as possible, thereby further improving the combustion performance of the pyrolysis gas.

―Second Embodiment―

Next, a waste treatment facility and a cement manufacturing facility according to a second embodiment of the present invention will be described with reference to FIG. 6 . This figure corresponds to FIG. 1 of the above-mentioned first embodiment. Also, in this embodiment, the structure of the suspension preheater 10 and the calciner 20 of the cement manufacturing equipment 200 is different from that of the first embodiment, but the calciner 20 is the same as the first embodiment except that there is no air inlet 25. The embodiment is the same, so the same symbol 20 is used. Other components having the same configuration are also denoted by the same reference numerals and their descriptions are omitted.

In addition, in the cement production facility 200 of the second embodiment, the hanging preheater 10 is divided into two systems, and each system includes, for example, a five-stage cyclone 11 . In the system on the left side of the figure, the kiln exhaust gas is blown in from the lower stage, and it is the same as the first embodiment except that the calciner 20 is not provided. On the other hand, in the system on the right side of the figure, the calciner 20 is provided, but what flows here is not the kiln exhaust gas but the high-temperature cooler exhaust gas from the air quenching cooler 40 .

As mentioned above, the cooler exhaust gas flows into the lower end of the calciner 20 like the kiln exhaust gas in the first embodiment, and is blown upward as a jet flow (shown by a dotted line in the figure). This cooler exhaust gas is mixed with the pyrolysis gas introduced into the decomposition furnace 20 . While making it burn, the cement raw material is blown upward, from the upper pipe 22 to the cyclone 11 of the lowest stage. And it goes up through the cyclone 11 step by step, and flows out from the uppermost cyclone 11 to the exhaust gas pipeline 50 .

In the lower part of the calciner 20 (detailed illustration is omitted), cement raw material is supplied from the cyclone 11 as in the first embodiment, and a gas inlet 27 for introducing pyrolysis gas from the gasification furnace 1 is provided, but it is not provided. The inlet port 25 for the air used for combustion. That is, because, as described above, the cooler exhaust gas blown upward through the calciner 20 is composed of combustion air containing a large amount of oxygen, unlike the kiln exhaust gas.

Except that the air inlet 25 is not provided, the structure of the calciner 20 is the same as that of the first embodiment, and the pyrolysis gas is guided into the calciner 20 from the gas inlet 27 provided in the circumferential direction at the peripheral wall portion 23, along the peripheral wall portion. 23 inner surface rotates around the upper and lower axis 20a. That is, also in this embodiment, the pyrolysis gas is introduced into the decomposition furnace 20 in a form that does not directly interfere with the main flow of cooler exhaust gas.

Therefore, the pyrolysis gas does not pass over the decomposition furnace 20 along with the main flow of cooler exhaust gas, but slowly mixes while spiraling around the main flow of cooler exhaust gas blowing upwards, and is fully combusted. By means of this combustion, the temperature of the cooler exhaust gas rises above 900°C. With this, the calcination (decarbonation reaction) of the blown cement raw material is promoted.

Also, in the pyrolysis gas from the waste, sometimes containing dioxins, in order to decompose it, it is necessary to maintain an atmosphere of more than 850°C for about 2 seconds or more, but in this embodiment, The temperature of the pyrolysis gas burned in the decomposition furnace 20 is maintained for more than 4 seconds, at a temperature above 900° C., and the dioxin (heterogeneous) can be fully decomposed.

Therefore, as described in the second embodiment, even in the case where the exhaust gas from the cooler is flowed into the decomposition furnace 20, by introducing the pyrolysis gas from the gasification furnace 1 as a swirling flow that rotates relative thereto, the With the exhaust gas flow of the cooler being scraped away, the pyrolysis gas can be fully combusted in the decomposition furnace 20.

―Other Embodiments―

In addition, the description of the said embodiment is an illustration only, and this invention does not intend to limit the thing to which it applies, or its use. For example, in the above-mentioned first embodiment, pyrolysis gas is introduced into the calciner 20 of the cement manufacturing equipment 200, and the air flow is rotated around the main flow of the kiln exhaust gas, and the combustion air is introduced below it to rotate side by side. limited to this.

That is, the combustion air may be introduced into the decomposition furnace 20 above the swirling flow of the pyrolysis gas, or both the combustion air and the pyrolysis gas may be introduced without swirling. In short, it is sufficient to introduce the pyrolysis gas without directly interfering with the main flow of the kiln exhaust gas in the calciner 20. Therefore, for example, when the kiln exhaust gas flows into the calciner 20 as a swirling flow, it may also flow along the swirling flow. The center of rotation of the flow introduces the pyrolysis gas.

Furthermore, the structures of the gasification furnace 1 of the waste processing facility 100 and the kiln (sintering furnace) of the cement manufacturing facility 200 are not limited to the above-mentioned respective embodiments. The gasification furnace 1 is not limited to the fluidized bed type, and the firing furnace is not limited to the rotary kiln 30, for example, a fluidized bed kiln may be used.

In addition, in each of the above-mentioned embodiments, the waste gas provided in the gasification furnace 1 is assumed to be general waste from households, industrial waste including waste plastics, etc., but it is not limited to this, and the gasification furnace may be 1Provide woody waste such as thinned wood and sawdust, or other animal and plant fuel waste such as livestock excrement and sewage sludge.

Industrial applicability

If the utility model is adopted, the pyrolysis gas of the waste generated by the gasification furnace can be transported to the decomposition furnace of the cement manufacturing equipment under the condition of keeping the carbon and ash content intact, so that it can be fully burned. The existing cement manufacturing equipment can be effectively utilized, and the sanitary treatment of waste can be realized at low cost, and the industrial application value is very high.

Claims (9)

1. offal treatment equipment, described offal treatment equipment is configured to and possesses the cement firing furnace, its burned material is carried out the adjacent setting of cement making equipment of the decomposing furnace of refrigerative clinker cooler and any one the inflow high-temp waste gas from this firing furnace and clinker cooler, it is characterized in that described offal treatment equipment possesses

Make the vapourizing furnace of waste gasification generation thermolysis gas;

To keep being transported under institute's carbon containing and the intact situation of ash content the gas delivery channels of described decomposing furnace at the thermolysis gas that described vapourizing furnace takes place; And

In described decomposing furnace, introduce the gas introduction unit of thermolysis gas from described gas delivery channels with the not direct form that interferes with the main flow that flows into the described high-temp waste gas in the described decomposing furnace of the air-flow of thermolysis gas.

2. offal treatment equipment according to claim 1 is characterized in that,

Described decomposing furnace has the tubular perisporium, and is configured to a end from its cylinder axis direction to the other end, forms the main flow from the exhaust flow of described firing furnace or clinker cooler;

Described gas introduction unit is provided with by sensing Zhou Fangxiang on described tubular perisporium, constitutes around the described gas introduction port that imports thermolysis gas on every side rotatably.

3. offal treatment equipment according to claim 2 is characterized in that,

The tubular perisporium of described decomposing furnace is configured to extend upward at upper and lower, constitutes jet flow, points upwards so that flow into the waste gas from described firing furnace or clinker cooler of its lower end;

On the other hand, described gas introduction port is configured to big and at the following angles of inclination importing thermolysis gases of 40 degree with downward-sloping ratio 0 degree with respect to the horizontal plane.

4. offal treatment equipment according to claim 3 is characterized in that, described gas introduction port is configured to import thermolysis gas with the flow velocity of 5～30m/s.

5. offal treatment equipment according to claim 2 is characterized in that,

Described offal treatment equipment is configured to make the lower end that flows into the tubular perisporium of described decomposing furnace from the waste gas of described firing furnace, on the other hand, described offal treatment equipment also possesses the air introducing port of the air of the importing burning usefulness that is arranged on this tubular perisporium bottom, to form swirling eddy on the direction identical with thermolysis gas;

Wherein, described offal treatment equipment is configured to above described air introducing port, with the interval of stipulating described gas introduction port is set.

6. offal treatment equipment according to claim 5 is characterized in that, described air introducing port is configured to introduce with the angle of inclination of downward-sloping regulation with respect to the horizontal plane the air of burning usefulness.

7. offal treatment equipment according to claim 5 is characterized in that,

The pipeline that connects the inlet that extends the described firing furnace of back L font warpage ground arrival downwards in the lower end of described decomposing furnace;

Described gas introduction port is arranged at the opposition side of described firing furnace one side in the tubular perisporium of described decomposing furnace.

8. offal treatment equipment according to claim 2 is characterized in that, the fuel feed mouth is set near the above gas introduction port of tubular perisporium of described decomposing furnace.

9. offal treatment equipment according to claim 2, it is characterized in that, offal treatment equipment possesses the described vapourizing furnace more than two, carries the gas delivery channels more than two of thermolysis gas to be communicated with the plural gas introduction port that the tubular perisporium of described decomposing furnace is provided with respectively from each vapourizing furnace.

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