Tail gas centralized treatment system

Abstract

The utility model relates to the technical field of tail gas treatment, and discloses a tail gas centralized treatment system which comprises a granulator, a primary dryer, a secondary dryer, a first screening machine, a primary cooler, a second screening machine, a secondary cooler, a coating machine, a finished product bin and an automatic bag stacking area which are connected in sequence, the granulator is communicated with a granulation tail gas treatment pipeline, and a venturi scrubber is arranged on the granulation tail gas treatment pipeline; the first-stage dryer and the second-stage dryer are communicated with drying tail gas treatment pipelines, cyclone dust collectors are arranged on the drying tail gas treatment pipelines, and tail gas treated by the cyclone dust collectors is communicated to the settling chamber; the venturi scrubber and the settling chamber are both connected to a scrubbing tower, and the scrubbing tower is connected with a pickling tank. The technical problems that in the existing ammonia-acid method compound fertilizer production process, alkaline substance pollution exists, tail gas multi-point emission exists, and the supervision difficulty is large are solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to tail gas treatment technical field, concretely relates to a tail gas centralized treatment system. BACKGROUND

[0002] In the ammonia acid method compound fertilizer production device, the tail gas composition produced in different links is complex and contains various pollutants. The utility model discloses a kind of tail gas dust removal device for compound fertilizer production, by setting tail gas dust suction point at raw material hopper, raw material crusher, fine powder vibrating screen, secondary drying machine, large particle vibrating screen and finished product rotary vibrating screen, connect bag dust collector to carry out dust removal;Set tail gas dust suction point at granulator, connect settling chamber, venturi scrubber and washing liquid tank and plastic burning plate dust collector to carry out dust removal, plastic burning plate dust collector is equipped with on-line cleaning system, tail gas is discharged after washing in washing tower again, and washing liquid is discharged to settling tank by washing liquid tank;Set tail gas dust suction point at primary drying machine, secondary drying machine and finished product cooling machine, connect cyclone dust collector and bag dust collector to carry out dust removal, realize good dust removal effect, dust removal efficiency is high, reach tail gas emission standard;In addition, cyclone dust collector is added at fine powder vibrating screen, large particle vibrating screen and finished product rotary vibrating screen, and better dust removal effect can be realized, and dust removal efficiency is improved.

[0003] However, the traditional processing mode still has the following problems:

[0004] 1, cannot remove the alkaline harmful substance in tail gas completely, still exist certain environmental pollution risk.

[0005] 2, waste material after drying still needs to carry out tail gas treatment in subsequent screening, cooling, packaging and the like area, but the point-by-point processing mode adopted in prior art, tail gas of each link is separately connected cyclone dust collector, bag dust collector and the like equipment, equipment quantity is much, energy consumption is scattered, maintenance cost is high;And the tail gas after processing is multi-point emission, and supervision difficulty is big. UTILITY MODEL CONTENTS

[0006] The utility model intends to provide a kind of tail gas centralized treatment system to solve the technical problem that there is alkaline substance pollution.

[0007] To achieve the above object, the utility model adopts the following technical scheme:

[0008] A kind of tail gas centralized treatment system, including the granulator, primary dryer, secondary dryer, first screening machine, primary cooler, second screening machine, secondary cooler, film coating machine, finished product bin, automatic packing area that are sequentially arranged;

[0009] The granulator is communicated with granulation tail gas treatment pipeline, fan and venturi scrubber are arranged on the granulation tail gas treatment pipeline;

[0010] The first-stage dryer and the second-stage dryer are connected with a drying tail gas treatment pipeline, and a cyclone dust collector is arranged on the drying tail gas treatment pipeline; the tail gas treated by the cyclone dust collector is connected to a settling chamber;

[0011] The exhaust pipelines of the settling chamber and the Venturi scrubber are connected to a washing tower, and the washing tower is connected with an acid washing pool; the liquid discharge pipeline of the Venturi scrubber is connected to the acid washing pool;

[0012] The first screening machine, the second screening machine, the second-stage cooler, the coating machine, the finished product bin and the automatic bale packing area are each provided with a tail gas branch pipeline, the tail gas branch pipelines are connected to a tail gas main pipeline, the tail gas main pipeline is connected to the air inlet of the first-stage cooler, and the first-stage cooler is provided with a cooling tail gas discharge pipeline, which is sequentially connected to a cyclone dust collector, a bag dust collector and a fan.

[0013] Preferably, as an improvement, a urea-formaldehyde reaction zone is further included, and a urea-formaldehyde reaction tail gas pipeline is arranged at the urea-formaldehyde reaction zone, the urea-formaldehyde reaction tail gas pipeline is connected to the granulation tail gas treatment pipeline, and the connection point is located between the granulator and the Venturi scrubber.

[0014] Preferably, as an improvement, the urea-formaldehyde reaction zone includes a urea-formaldehyde reaction tank and a urea-formaldehyde intermediate tank, and the urea-formaldehyde reaction tail gas pipeline is used to suck tail gas at the urea-formaldehyde reaction tank and the urea-formaldehyde intermediate tank.

[0015] Preferably, as an improvement, a phosphorus-ammonium dissolution zone is further included, and a phosphorus-ammonium dissolution tail gas pipeline is arranged at the phosphorus-ammonium dissolution zone, the phosphorus-ammonium dissolution tail gas pipeline is connected to the granulation tail gas treatment pipeline, and the connection point is located between the granulator and the Venturi scrubber.

[0016] Preferably, as an improvement, the phosphorus-ammonium dissolution zone includes a phosphorus-ammonium dissolution tank and a phosphorus-ammonium intermediate tank, and the phosphorus-ammonium dissolution tail gas pipeline is used to suck tail gas at the phosphorus-ammonium dissolution tank and the phosphorus-ammonium intermediate tank.

[0017] Preferably, as an improvement, the urea-formaldehyde reaction tail gas pipeline and the phosphorus-ammonium dissolution tail gas pipeline are combined into one pipeline before being connected to the granulation tail gas treatment pipeline.

[0018] Preferably, as an improvement, a washing pool is further included, and a water inlet pipeline is arranged on the washing pool; a water outlet is arranged on the washing pool and used to be connected to the washing tower, the Venturi scrubber, the phosphorus-ammonium dissolution tank, the urea-formaldehyde reaction tank and the granulator.

[0019] Preferably, as an improvement, a coarse material crusher is further included and connected to the second screening machine, the crushed material of the coarse material crusher is supplied to the granulator; a crushing tail gas pipeline is arranged at the coarse material crusher and connected to the tail gas main pipeline; and the fine material screened by the first screening machine is returned to the granulator.

[0020] Preferably, as an improvement, the sulfuric acid storage tank, the tubular reactor, the urea-formaldehyde intermediate tank, the ammonium phosphate intermediate tank and the sulfuric acid storage tank are all communicated with the tubular reactor; the tubular reactor is further communicated with an ammonia pipe; and the intermediate product formed in the tubular reactor is put into the granulator.

[0021] Preferably, as an improvement, the washing tank and the pickling tank are separated by a partition wall, and the partition wall is provided with an overflow hole near the upper portion.

[0022] Advantages:

[0023] 1. For the tail gas discharged from the granulation, part of the impurities and particulate matters are removed by the Venturi scrubber, and then the tail gas is sent into the washing tower and the pickling tank for two-stage washing to further remove the alkaline substances and other pollutants, and finally the tail gas is discharged at a high altitude through the chimney. The tail gas discharged from the first drying and the second drying is first subjected to dust removal by the cyclone dust collector and the settling chamber to preliminarily remove the dust with larger particles, and then the tail gas is sent into the washing tower and the pickling tank for two-stage washing, and finally the tail gas is discharged at a high altitude; which can further ensure the removal of alkaline substances.

[0024] 2. The first screening machine and the second screening machine respectively realize coarse screening and fine screening of the fertilizer particles, and the finer and coarser particles are recycled into the granulator, which will not cause waste; and the uniformity of the final product particles can be further ensured. In addition, the tail gas of the first screening machine, the second screening machine, the second cooling machine, the coating machine, the finished product bin and the automatic baling area can be collected on the tail gas main pipe, and then collected into the air inlet of the first cooling machine, and then discharged at a high altitude after being subjected to cyclone dust removal and bag dust removal together with the cold tail gas of the first cooling machine, so that the tail gas of different links is concentrated and treated. The advantages of this are as follows: on the one hand, the tail gas of the first cooling machine has a lower temperature and a moderate humidity, which is more suitable for the operating conditions of the bag dust collector, and can avoid high-temperature bag sticking or low-temperature condensation; for example, if a dryer is selected as the collection point, the high-temperature tail gas may damage the bag dust collector. On the other hand, the composition of the tail gas of the first cooling machine is relatively simple, and the treatment difficulty is lower compared to the treatment of the tail gas mixed with the tail gas of other links.

[0025] 3. The tail gas generated by urea-formaldehyde reaction and ammonium phosphate dissolution is collected and connected to the tail gas treatment pipeline of the granulator. The tail gas collected by urea-formaldehyde reaction and ammonium phosphate dissolution may contain acidic substances, which can be mixed with alkaline substances in the tail gas when entering the tail gas treatment pipeline of the granulator, so as to achieve better tail gas treatment effect. Subsequently, the tail gas is subjected to removal of part of the impurities and particulate matters by the Venturi scrubber, and then sent into the washing tower and the pickling tank for two-stage washing to further remove harmful substances and other pollutants, which can further ensure that the discharged gas meets the standard.

[0026] 4. The design of the washing water tank allows for centralized supply of liquid to the washing tower, Venturi scrubber, phosphate and ammonium dissolution tank, urea-formaldehyde reaction tank, granulator, etc., facilitating monitoring. The pickling tank and washing water tank are separated by a partition wall with an overflow hole near the top. Higher liquid levels will flow from the overflow hole to the other tank, preventing overflow caused by liquid discharged from the Venturi scrubber entering the pickling tank. Furthermore, more liquid can be supplied from the washing water tank.

[0027] In summary, this technology, through a rationally designed centralized exhaust gas treatment system, effectively removes various pollutants from the granulator and exhaust gas, including dust, alkaline and acidic substances, ensuring that the emitted exhaust gas meets environmental standards and reducing atmospheric pollution. This centralized treatment method optimizes the traditional processing flow, reduces redundant equipment setup, the number of equipment and floor space required, and lowers equipment investment and operation and maintenance costs. It also improves the collaborative working ability of the equipment, enhances the stability and reliability of the entire exhaust gas treatment system, and reduces the probability of malfunctions. Moreover, the above design significantly reduces multi-point exhaust gas emissions, especially with the unified emission outlet design after drying, making monitoring more controllable. It is worth noting that the inventors have uniquely chosen the primary cooler as the centralized treatment point, which is less difficult to treat than exhaust gas mixed with other stages. Subsequent treatment by cyclone dust collectors and bag filters is sufficient to achieve the desired effect. More importantly, by centrally collecting the exhaust gases generated from the urea-formaldehyde reaction and ammonium phosphate dissolution into the granulator exhaust gas treatment pipeline for centralized treatment, acidic and alkaline gases can be mixed, further reducing the environmental pollution caused by subsequent acidic and alkaline substances. Therefore, this utility model patent combines a centralized treatment technical solution to solve the exhaust gas treatment problem in compound fertilizer production equipment. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this utility model.

[0029] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of this utility model.

[0030] Figure 3 for Figure 2 A schematic diagram of the structure of the washing tower, washing water tank, and pickling tank. Detailed Implementation

[0031] The following detailed description illustrates the specific implementation method:

[0032] The reference numerals in the accompanying drawings include: washing tower 1, washing water tank 2, pickling tank 3, partition wall 4, and overflow hole 41.

[0033] Example 1

[0034] Basically as shown in the accompanying Figure 1 The tail gas treatment system comprises a granulator, a first dryer, a second dryer, a first screening machine, a first cooler, a second screening machine, a second cooler, a coating machine, a finished product bin, an automatic packaging machine, an automatic baling machine and a finished product warehouse arranged in sequence. In order to treat the tail gas of the granulator and avoid environmental pollution caused by emptying of alkaline substances and other pollutants, a granulation tail gas treatment pipeline is arranged at the granulator, and the specific connection mode can be determined according to the site conditions. For example, the granulation tail gas treatment pipeline is directly connected to the exhaust port of the granulator, or a flared collecting hood is arranged above the granulator in the workshop, and the granulation tail gas treatment pipeline is connected to the collecting hood. A fan, a venturi scrubber and a washing tower are sequentially connected to the granulation tail gas treatment pipeline. The tail gas is removed of part of impurities and particulate matters by the venturi scrubber, then enters the washing tower through the venturi scrubber exhaust port, and is discharged from the top of the washing tower after being washed. The alkaline substances in the gas fall into the washing liquid tank at the bottom of the washing tower. The liquid outlet of the washing tower is connected to an acid washing pool, and the liquid containing alkaline substances enters the acid washing pool. The liquid outlet of the venturi scrubber is also connected to the acid washing pool.

[0035] A drying tail gas treatment pipeline is connected to the first dryer and the second dryer, and a fan and a cyclone dust collector are sequentially arranged on the drying tail gas treatment pipeline. The tail gas treated by the cyclone dust collector is connected to a gravity settling chamber. The gravity settling chamber is also connected to the washing tower connected to the granulation tail gas treatment pipeline, so that the part of the tail gas is also washed by the washing tower. A spray pipe is arranged at the upper part of the washing tower, a gas inlet is arranged at the bottom of the washing tower, and a gas outlet is arranged at the top of the washing tower. The tail gas entering from the bottom is washed by contacting with the washing liquid sprayed downward in the process of rising upward. A demisting layer or a demister is arranged at the top of the washing tower. The gas discharged from the washing tower is demisted and then discharged from a chimney.

[0036] Tail gas branch pipes are arranged at the first screening machine, the second screening machine, the second cooler, the coating machine, the finished product bin and the automatic baling area. The tail gas branch pipes can be connected to the exhaust ports of the above-mentioned devices, or flared air suction hoods are fixed on the devices by supports, and the tail gas branch pipes are connected to the air suction hoods. The tail gas branch pipes are connected to a tail gas main pipe, and the tail gas main pipe is connected to the air inlet of the first cooler. A cooling tail gas discharge pipe is arranged on the first cooler, and the cooling tail gas discharge pipe is sequentially connected to a cyclone dust collector, a bag dust collector and a fan.

[0037] The technology also includes a urea-formaldehyde reaction zone, an ammonium phosphate dissolving zone, the urea-formaldehyde reaction zone includes a urea-formaldehyde reaction tank and a urea-formaldehyde intermediate tank, the upper part of the urea-formaldehyde reaction tank and the urea-formaldehyde intermediate tank is communicated with a urea-formaldehyde reaction tail gas pipe for absorbing the gas at the urea-formaldehyde reaction tank and the urea-formaldehyde intermediate tank. The ammonium phosphate dissolving zone includes an ammonium phosphate dissolving tank and an ammonium phosphate intermediate tank, the upper part of the ammonium phosphate dissolving tank and the ammonium phosphate intermediate tank is communicated with an ammonium phosphate dissolving tail gas pipe for absorbing the tail gas at the ammonium phosphate dissolving tank and the ammonium phosphate intermediate tank. The urea-formaldehyde reaction tail gas pipe and the ammonium phosphate dissolving tail gas pipe are combined into a pipe before being communicated with the granulation tail gas treatment pipe, the pipe is communicated to the granulation tail gas treatment pipe, and the connection point is located between the granulator and the fan. The urea-formaldehyde intermediate tank and the ammonium phosphate intermediate tank are used to store the raw materials after reaction and dissolving.

[0038] The technology also includes a coarse material crusher connected at the second screening machine, the coarse material screened by the second screening machine is put into the coarse material crusher for crushing, and then is put into the granulator; the coarse material crusher is provided with a crushing tail gas pipe which is communicated with the tail gas main pipe. The fine material screened by the first screening machine is returned to the granulator. Specifically, the first screening machine and the second screening machine are both two-layer structures, and the first screening machine is taken as an example for illustration. The first screening machine includes a screening chamber and a screen located in the screening chamber, the lower part of the screening chamber is provided with a vibrator, and the inner wall of the screening chamber is provided with an inward edge for supporting and fixing the screen by screws. The upper part of the screening chamber is provided with an upper outlet located above the screen and a lower outlet located below the screen, and the screen and the bottom surface of the screening chamber are both inclined surfaces inclined toward the outlet direction. In the first screening machine, the coarse material is left at the top of the screen, and the fine material is at the bottom of the screen, which is collected from the lower outlet and then transported to the inlet of the granulator. The structure of the second screening machine is the same as that of the first screening machine, except that the coarse material collected by the second screening machine is put into the crusher for crushing and then transported to the inlet of the granulator.

[0039] The technology also includes a tubular reactor, a sulfuric acid storage tank, a urea-formaldehyde intermediate tank, and an ammonium phosphate intermediate tank which are all communicated with the tubular reactor; the tubular reactor is also communicated with an ammonia pipe and a sulfuric acid pipe; the intermediate product finally formed in the tubular reactor is put into the aforementioned granulator. It is worth mentioning that a pump can be arranged on the liquid pipeline in the technology for conveying liquid, and a fan can be arranged on the gas pipeline for pumping gas. Figure 1 In the embodiment, pumps and fans are shown at some positions, however, the arrangement of pumps and fans is the existing technology in the field, and in practice, pumps and fans can be arranged at appropriate positions as needed, therefore, other liquid / gas pipelines except the pumps / fans shown in the figure can also be arranged as needed, which will not be described here. In other embodiments except the embodiment, a pump is not arranged on the liquid communication pipeline between the washing tower and the pickling tank, but the washing tower is arranged at a high position and the pickling tank is arranged at a low position, so that the liquid at the bottom of the washing tower flows into the pickling tank by the height difference.

[0040] Embodiment 2

[0041] As Figure 2 , 3 shown, the difference between this embodiment and embodiment 1 is that the present technology also includes a washing pool 2, and the water inlet pipe of the washing pool 2 is communicated with a rainwater collection pool and a purified domestic sewage pool; a direct water pipe is also provided on the washing pool 2 for connecting tap water. The rainwater collection pool, the purified domestic sewage pool and the direct water pipe can all be used to supply water to the washing pool 2. The washing pool 2 is communicated with the washing tower 1, the venturi scrubber, the phosphonium ammonium dissolution tank, the urea-formaldehyde reaction tank and the granulator. The pickling pool 3 and the washing pool 2 are separated by a partition wall 4, the partition wall 4 is provided with an overflow hole 41 near the upper part, and a higher liquid level will flow from the overflow hole 41 to the other pool, especially, the liquid outlet of the venturi scrubber will discharge the solution to the pickling pool 3, which may cause the pickling pool 3 to overflow, and the addition of the overflow hole 41 makes the liquid in the pickling pool 3 can enter the washing pool 2, and the washing pool 2 can have more liquid supply. The present technology also provides a sulfuric acid storage tank for supplying sulfuric acid to the pickling pool 3 and the reactor. In Figure 2 , the pumps at some positions in the above-mentioned pipeline are shown, and pumps can also be provided in other liquid pipelines according to the needs of the pumps for pumping liquid, which will not be described here. In other embodiments other than this embodiment, a liquid outlet is provided at the bottom of each of the above-mentioned pools for use in cleaning, and a cover is used to block it in normal times.

[0042] The above is only an embodiment of the present application, and the specific technical solutions and / or common knowledge of the scheme are not described in detail here. It should be noted that for those skilled in the art, without departing from the technical solutions of the present application, a number of modifications and improvements can be made, which should also be considered as the protection scope of the present application, and these will not affect the effect and practicality of the present application. The protection scope of the present application should be subject to the content of its claims, and the specific implementation mode and the like in the specification can be used to explain the content of the claims.

Claims

1. A tail gas centralized treatment system, characterized in that: The granulator, the first-stage dryer, the second-stage dryer, the first screening machine, the first-stage cooler, the second screening machine, the second-stage cooler, the coating machine, the finished product bin and the automatic bale packing area are sequentially arranged. The granulator is connected with a granulation tail gas treatment pipeline, and a fan and a Venturi scrubber are arranged on the granulation tail gas treatment pipeline. The first-stage dryer and the second-stage dryer are connected with a drying tail gas treatment pipeline, and a cyclone dust collector is arranged on the drying tail gas treatment pipeline. The exhaust pipelines of the settling chamber and the Venturi scrubber are connected to a washing tower, and the washing tower is connected with an acid washing tank. The exhaust pipeline of the Venturi scrubber is connected to the acid washing tank.

2. The exhaust gas centralized treatment system according to claim 1, characterized in that: The first screening machine, the second screening machine, the second-stage cooler, the coating machine, the finished product bin and the automatic bale packing area are provided with tail gas branch pipes, the tail gas branch pipes are connected to a tail gas main pipe, the tail gas main pipe is connected to an air inlet of the first-stage cooler, and a cooling tail gas exhaust pipe is arranged on the first-stage cooler.

3. The exhaust gas centralized treatment system according to claim 2, wherein: The cooling tail gas exhaust pipe is sequentially connected to a cyclone dust collector, a bag dust collector and a fan.

4. The exhaust gas centralized treatment system according to claim 3, characterized in that: The urea-formaldehyde reaction zone includes a urea-formaldehyde reaction tank and a urea-formaldehyde intermediate tank, and the urea-formaldehyde reaction tail gas pipe is used to suck tail gas from the urea-formaldehyde reaction tank and the urea-formaldehyde intermediate tank.

5. The exhaust gas centralized treatment system according to claim 4, characterized in that: The phosphammonium dissolution zone includes a phosphammonium dissolution tank and a phosphammonium intermediate tank, and the phosphammonium dissolution tail gas pipe is used to suck tail gas from the phosphammonium dissolution tank and the phosphammonium intermediate tank.

6. The exhaust gas centralized treatment system according to claim 5, characterized in that: The urea-formaldehyde reaction tail gas pipe and the phosphammonium dissolution tail gas pipe are combined into one pipeline before being connected to the granulation tail gas treatment pipeline.

7. The exhaust gas centralized treatment system according to claim 6, characterized in that: The washing water tank is provided with an inlet pipe and an outlet, which are connected to the washing tower, the Venturi scrubber, the phosphammonium dissolution tank, the urea-formaldehyde reaction tank and the granulator.

8. The exhaust gas centralized treatment system according to claim 7, characterized in that: The coarse material crusher is connected to the second screening machine, and the crushed material is returned to the granulator.

9. The exhaust gas centralized treatment system according to claim 8, wherein: The urea-formaldehyde intermediate tank, the phosphammonium intermediate tank and the sulfuric acid storage tank are connected to the tubular reactor, and the tubular reactor is further connected with an ammonia pipe.

10. The exhaust gas centralized treatment system according to claim 9, wherein: The intermediate product formed in the tubular reactor is put into the granulator. The washing water tank and the acid washing tank are separated by a partition wall, and the partition wall is provided with overflow holes near the upper part.

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