CN112404110B - Method and system for treating waste salt containing organic matter using double-cycle thermal purification technology - Google Patents

Abstract

The invention provides a method for treating waste salt containing organic matters by adopting a double-circulation thermal purification technology, which relates to the technical field of solid waste treatment, and comprises the steps that the waste salt containing the organic matters is decomposed into purified industrial waste salt and flue gas after entering a thermal kiln through a feeding bin; after entering the intermediate bin, the purified industrial waste salt is divided into two paths, wherein one path of the purified industrial waste salt enters the feeding bin in a recycling way through a variable-frequency reflux conveying system, and the other path of the purified industrial waste salt is discharged outwards through a finished product bin; the flue gas is divided into two paths after dust removal, combustion and purification, one path is circulated to the thermal kiln, and the other path is discharged outwards. The invention also provides a system adopting the method. The invention adopts a double-circulation mode to reduce TOC content of dried organic waste salt from 800ppm to 20000ppm to below 100ppm so as to meet the requirements of further impurity removal and salt separation, realize recycling of waste salt, simultaneously purify industrial waste salt for recycling, and overcome the phenomenon of melting and caking in the treatment process of the organic waste salt.

Description

Method and system for treating waste salt containing organic matter using double-cycle thermal purification technology

technical field

The invention relates to the technical field of solid waste treatment, in particular to a method and system for treating waste salt containing organic matter by adopting double-cycle thermal purification technology.

Background technique

Waste salt producers mainly include coal chemical industry, pesticide, pharmaceutical, fine chemical industry, printing and dyeing and other national key industries. Chemical waste salt pollution is very serious, directly endangering human health, destroying the ecological environment, and can cause deterioration of surface water and groundwater quality, and salinization of land.

The amount of waste salt is huge, the market for recycled products is limited, the value of raw salt is low, and the cost of purification is high. It may enter the food chain and directly endanger human health. Its harmless management is very difficult. At present, the harmless management measures of waste salt mainly include: emission reduction, production of chemical raw materials, sea discharge and landfill.

With the improvement of environmental protection requirements, the existing disposal methods can no longer meet the requirements of harmless management of waste salt, especially for the three major industries of pesticides, medicine and printing and dyeing, the disposal of waste salt has become a bottleneck restricting the development of the industry.

Due to the large amount of waste salt produced, unsuitable for incineration, and restricted landfill, the resource disposal of waste salt is a feasible and harmless management approach. However, there is no mature resource disposal technology for chemical waste salt at home and abroad. The disposal of salt resources involves various key technologies such as organic matter removal, impurity removal and salt separation, all of which need further breakthroughs.

Among them, the removal of organic matter is a key link in the resource utilization of waste salt. How can the TOC (total organic carbon) in waste salt be reduced to below 100ppm to lay a good foundation for subsequent impurity removal and salt separation processes? Through the application of multi-energy channels, waste salt and flue gas dual cycle technology, to achieve the best energy practice and avoid the occurrence of melting and agglomeration in waste salt treatment has become a technical problem to be solved urgently by those skilled in the art.

Contents of the invention

In view of this, one of the purposes of the present invention is to provide a method for treating waste salt containing organic matter using dual-cycle thermal purification technology to solve the problem of TOC (total organic carbon) content of the dried chemical waste salt in the prior art. It varies from 800ppm to 20000ppm, so it cannot lay a good foundation for the subsequent impurity removal and salt separation process, and there is a technical problem of melting and agglomeration in waste salt treatment.

The second object of the present invention is to provide a system for treating waste salt containing organic matter using double-cycle thermal purification technology.

In order to achieve one of the above objectives, the present invention provides a method for treating waste salt containing organic matter by adopting double-cycle thermal purification technology, the method comprising:

Organic waste salt is decomposed into purified industrial waste salt and flue gas after entering the thermal kiln through the feed bin;

The purified industrial waste salt is divided into two paths after entering the intermediate bin, and one path is recirculated into the feed bin through the frequency conversion return conveying system, and mixed with the untreated organic waste salt in the feed bin, together Enter the thermal kiln again, and discharge outwards through the finished product warehouse all the way;

The flue gas is divided into two paths after dust removal, combustion and purification, one path is circulated to the thermal kiln, and the other path is discharged outward.

According to a preferred embodiment, the organic waste salt needs to be pretreated before entering the feed bin, and then enters the thermal kiln through the feed bin, and stays in the thermal kiln for 30-120min. The organic matter in the organic matter waste salt is thermally decomposed into the flue gas and the purified industrial waste salt.

According to a preferred embodiment, the thermal kiln is a rotary thermal kiln with an inclination angle of 2°-5°, and the thermal kiln rotates 360 degrees.

According to a preferred embodiment, the thermal kiln is driven to rotate by a rotating motor, and the frequency of the rotating motor is changed to adjust the residence time of the organic waste salt in the thermal kiln.

According to a preferred embodiment, the temperature of the thermal kiln is adjustable within the range of 300°C-600°C, and the temperature can be adjusted by changing the power of the heating device of the thermal kiln, the combustion temperature of the flue gas and the circulating flue gas gas flow.

According to a preferred embodiment, the heating device is an electric heater or a burner.

According to a preferred embodiment, the circulating flue gas enters the kiln tail of the thermal kiln tangentially.

According to a preferred embodiment, the kiln hood of the thermal kiln adopts a sinking structure to separate the purified industrial waste salt and the flue gas.

In order to achieve the above-mentioned second objective, the present invention provides a system for treating waste salt containing organic matter by adopting double-cycle thermal purification technology, including a waste organic salt treatment system and a flue gas treatment system, wherein:

The organic waste salt treatment system includes a feed bin, a thermal kiln for decomposing organic waste salt, an intermediate bin, a finished product bin, and a return conveying system. The feed bin, the thermal kiln, the intermediate bin, and the The finished product bins are connected end to end and communicated in sequence. The thermal kiln decomposes the organic waste salt to form purified industrial waste salt and flue gas. The thermal kiln is connected and communicated with the feed bin through the return conveying system at the same time. The purified industrial waste salt flows back to the feed bin through the return conveying system all the way, and discharges outward through the finished product bin all the way;

The flue gas treatment system is connected and communicated with the thermal kiln, and after being discharged from the thermal kiln, the flue gas is processed by the flue gas treatment system, circulated all the way to the thermal kiln, and is discharged all the way to the outside.

According to a preferred embodiment, the flue gas treatment system includes a dust collector, a combustion chamber, a flue gas purification device and a circulating fan, the dust collector is connected and communicated with the thermal kiln, the dust collector, the combustion chamber , the flue gas purification device and the circulating fan are connected end to end in sequence, the flue gas is discharged from the thermal kiln and passes through the dust collector successively for dust removal, after the combustion chamber is burned and the flue gas purification device purifies , circulated to the thermal kiln through a circulating fan.

According to a preferred embodiment, it also includes an induced draft fan and a chimney, the induced draft fan is connected to the chimney and the flue gas purification device at the same time, and the induced draft fan is used to discharge the gas after being purified by the flue gas purification device to the outside standard flue gas.

According to a preferred embodiment, the flue gas purification device includes a semi-dry quenching deacidification tower, an SNCR, a bag filter, a flue gas condenser and a flue gas heat exchanger.

According to a preferred embodiment, the thermal kiln is set as a rotary kiln with an inclination angle of 2°-5°.

According to a preferred embodiment, a rotating motor is installed at the bottom of the thermal kiln, the rotating motor is drivingly connected to the thermal kiln, and the frequency of the rotating motor is variable.

According to a preferred embodiment, an electric heater is installed on the thermal kiln, and the electric heater is divided into three independent circuits for controlling the temperature of the thermal kiln.

According to a preferred embodiment, a burner is installed on the thermal kiln, and the temperature of the thermal kiln is adjusted by controlling the power of the burner.

According to a preferred embodiment, the kiln head of the thermal kiln is provided with a humidifying water atomization spray gun and a water flow control circuit for controlling the water volume of the thermal kiln.

According to a preferred embodiment, the kiln head of the thermal kiln is provided with a nitrogen nozzle and a nitrogen flow control circuit for controlling the nitrogen volume of the thermal kiln.

According to a preferred embodiment, the kiln hood of the thermal kiln is set as a submerged structure.

The method provided by the present invention for treating waste salt containing organic matter by adopting double-cycle thermal purification technology has the following technical effects:

This method is mainly composed of two cycle thermal purification technologies. One is to purify industrial waste salt after entering the intermediate bin, and then enter the feeding bin through the frequency conversion backflow conveying system, and the untreated organic waste salt in the feeding bin The second is that the flue gas is divided into two paths after dust removal, combustion and purification, one path is recirculated to the thermal kiln, and the flue gas in the other path is discharged outside after reaching the standard. This double circulation method can The TOC content of the dried organic waste salt is reduced from 800ppm to 20000ppm to less than 100ppm to meet the needs of further impurity removal and salt separation, realize the resource utilization of waste salt, purify industrial waste salt and recycle, and overcome the problem of organic waste salt Melting agglomeration that occurs during processing.

The system provided by the present invention adopts double-cycle thermal purification technology to treat waste salt containing organic matter, and has the following technical effects:

This system corresponds to the above-mentioned method, that is, it is mainly composed of an organic matter waste salt treatment system and a flue gas treatment system. The organic matter treatment system includes a feed bin, a thermal kiln for decomposing organic matter waste salt, an intermediate bin, a finished product bin, and a return flow Conveyor system, feeding bin, thermal kiln, intermediate bin and finished product bin are connected end-to-end and connected in sequence. The thermal kiln decomposes organic waste salt to form purified industrial waste salt and flue gas. The thermal kiln is connected to the feeding bin through the return conveying system at the same time. And connected to form a cycle, the purified industrial waste salt is returned to the feed bin through the return conveying system; while the other cycle is the flue gas cycle, the flue gas treatment system is connected and communicated with the thermal kiln, and the flue gas is discharged from the thermal kiln and passes through The flue gas treatment system treats and returns to the thermal kiln for circulation. The use of this double circulation system can reduce the TOC content of the dried organic waste salt from 800ppm to 20000ppm to below 100ppm, so as to meet the needs of further impurity removal and salt separation, realize the resource utilization of waste salt, and purify industrial waste salt at the same time. It can also overcome the melting and agglomeration phenomenon in the process of organic waste salt treatment.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a flow chart of a system for treating waste salt containing organic matter using dual-cycle thermal purification technology according to an embodiment of the present invention;

Fig. 2 is the structural representation of thermal kiln among Fig. 1;

Fig. 3 is the sectional view of the kiln tail of thermal kiln in Fig. 2 along A-A direction;

Among them, Figure 1-Figure 3:

1. Organic matter waste salt treatment system; 101, feed bin; 102, thermal kiln; 1021, sinking structure; 1022, rotating motor; 1023, electric heater; 1024, kiln tail; 103, intermediate bin; 104, finished product bin ;

2. Flue gas treatment system; 201, dust collector; 202, combustion chamber; 203, flue gas purification device; 204, circulating fan; 205, induced draft fan; 206, chimney.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Apparently, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other implementations obtained by persons of ordinary skill in the art without making creative efforts fall within the protection scope of the present invention.

The technical solutions of the present invention will be further described below in conjunction with the embodiments.

An embodiment of the present invention provides a method for treating waste salt containing organic matter using a double-cycle thermal purification technology. The method includes: waste organic salt enters a thermal kiln 102 through a feed bin 101 and decomposes into waste salt for purification industry and flue gas; After the waste salt enters the intermediate bin 103, it is divided into two paths. One path is recirculated into the feed bin 101 through the frequency conversion return conveying system, mixed with the untreated organic waste salt in the feed bin 101, and then enters the thermal kiln 102 together. It is discharged through the finished product warehouse 104; the flue gas is divided into two paths after dust removal, combustion and purification, one path is circulated to the thermal kiln 102, and the other path is discharged outward.

The above method can be used for the harmless and resourceful treatment of chemical waste salt. The TOC content of the dried chemical waste salt ranges from 800ppm to 20000ppm. It is decomposed into purified industrial waste salt and flue gas. The purified industrial waste salt enters the intermediate bin 103 and then circulates into the feed bin 101 through the frequency conversion return conveying system to achieve the purpose of recycling treatment, while the flue gas is dedusted, burned and purified. It is also circulated to the thermal kiln 102, so that the TOC content in the waste salt is reduced to below 100ppm, which meets the requirements of further impurity removal and salt separation, and realizes the resource utilization of waste salt.

Further, the organic waste salt needs to be pretreated before entering the feeding bin 101, and then enters the thermal kiln 102 through the feeding bin 101, and stays in the thermal kiln 102 for 30-120 minutes, and the organic matter in the organic waste salt is thermally decomposed into flue gas and purification of industrial waste salt, while the purification of industrial waste salt is discharged to the intermediate bin 103 through the kiln tail 1024 of the thermal kiln 102, and the flue gas is subjected to dust removal, combustion and purification treatment.

Further, the thermal kiln 102 adopts a rotary thermal kiln 102 with an inclination angle of 2°-5°, and the thermal kiln 102 rotates at 360 degrees. Specifically, it is connected to the rotating motor 1022, and the rotation is driven by the rotating motor 1022 to change the rotation of the rotating motor 1022. The frequency can adjust the residence time of the organic waste salt in the thermal kiln 102, that is, the range of the residence time in the thermal kiln 102 is 30-120min.

Further, the temperature of the thermal kiln 102 is adjustable within the range of 300°C-600°C, and the temperature can be adjusted by changing the power of the heating device of the thermal kiln 102, the combustion temperature of the flue gas and the flow rate of the circulating flue gas.

It should be noted that the heating device of the present invention can be an electric heater 1023, a burner, or other types of heating devices, as long as the heating function of the thermal kiln can be realized, all within the protection scope of the present invention , the present invention is not limited thereto.

Further, the circulating flue gas enters the kiln tail 1024 of the thermal kiln 102 tangentially, that is, the circulating flue gas enters tangentially from the kiln tail 1024 of the thermal kiln 102 at 270°, as shown in Figure 2-3, the flue gas flows through the thermal kiln 102 to rotate forward, thereby increasing the contact area with the organic waste salt at the bottom of the thermal kiln 102 to achieve the effect of full contact.

Furthermore, the kiln hood of the thermal kiln 102 adopts a sinking structure 1021 to separate and purify industrial waste salt and flue gas, thereby realizing the separation of purified industrial waste salt and flue gas, and reducing the amount of purified industrial waste carried into the combustion chamber 202 by flue gas. amount of salt.

Another embodiment of the present invention provides a system for treating waste salt containing organic matter using double-cycle thermal purification technology, as shown in Figures 1-3, including a waste organic salt treatment system 1 and a flue gas treatment system 2, the organic matter treatment system Including feeding bin 101, thermal kiln 102 for decomposing organic waste salt, intermediate bin 103, finished product bin 104 and return conveying system, feeding bin 101, thermal kiln 102, intermediate bin 103 and finished product bin 104 are connected end to end in sequence And communicated, the thermal kiln 102 decomposes organic waste salt to form purified industrial waste salt and flue gas, and the thermal kiln 102 is connected and communicated with the feed bin 101 through the return conveying system at the same time, and the purified industrial waste salt flows back to the feed bin through the return conveying system all the way 101, one way is discharged outward through the finished product warehouse 104; the flue gas treatment system 2 is connected and communicated with the thermal kiln 102, and the flue gas is discharged from the thermal kiln 102 and processed by the flue gas treatment system 2, and circulated all the way to the thermal kiln 102, all the way to the outside emission.

The system of this embodiment corresponds to the method of the above-mentioned embodiment, that is, it is mainly composed of a waste organic salt treatment system 1 and a flue gas treatment system 2, and the waste organic salt treatment system 1 includes a feed bin 101, a chamber for decomposing waste organic salt Thermal kiln 102, intermediate warehouse 103, finished product warehouse 104 and return conveying system, feed warehouse 101, thermal kiln 102, intermediate warehouse 103 and finished product warehouse 104 are connected end-to-end and connected in sequence, and thermal kiln 102 decomposes organic waste salt to form a purification industry Waste salt and flue gas, the thermal kiln 102 is connected and communicated with the feed bin 101 through the return conveying system at the same time, forming a cycle, and the purified industrial waste salt is returned to the feed bin 101 through the return conveying system; while the other cycle is flue gas Circulation, the flue gas treatment system 2 is connected and communicated with the thermal kiln 102 , the flue gas is discharged from the thermal kiln 102 and is treated by the flue gas treatment system 2 , and then flows back to the thermal kiln 102 for circulation. The use of this double circulation system can reduce the TOC content of the dried organic waste salt from 800ppm to 20000ppm to below 100ppm, so as to meet the needs of further impurity removal and salt separation, realize the resource utilization of waste salt, and purify industrial waste salt at the same time It can also overcome the melting and agglomeration phenomenon in the process of organic waste salt treatment.

Purified industrial waste salt passes through the kiln tail 1024 of the thermal kiln 102, and then enters the intermediate bin 103. The purified industrial waste salt in the intermediate bin 103 is connected to the feed bin 101 through a frequency conversion backflow conveying system, and the purified industrial waste salt can be passed through the backflow conveying system. It circulates into the feed bin 101, mixes with the untreated industrial waste salt in the feed bin 101, and then enters the thermal kiln 102 together. By changing the frequency of the return conveying system, the amount of recycled industrial waste salt can be adjusted.

With the help of the mixture of purified industrial waste salt and unpurified industrial waste salt, it can play the following roles:

a. It can reduce the cohesion and clogging of industrial waste salt in the feed bin 101;

b, reduce the agglomeration of industrial waste salt in the thermal kiln 102;

c. Strengthen the heat transfer process and recover part of the heat.

Further, the flue gas treatment system 2 includes a dust collector 201, a combustion chamber 202, a flue gas purification device 203, and a circulating fan 204. The dust collector 201 is connected and communicated with the thermal kiln 102. 203 and circulating fan 204 are connected end to end in sequence. The flue gas discharged from thermal kiln 102 is dedusted by dust collector 201 successively.

It also includes an induced draft fan 205 and a chimney 206. The induced draft fan 205 is connected to the chimney 206 and the flue gas purification device 203 at the same time.

Specifically, the flue gas from the thermal kiln 102 enters the dust collector 201 to separate the salt that may be carried in the flue gas.

It should be noted that the combustion chamber 202 of the present invention is a sinking combustion chamber, and the flue gas from the dust collector 201 enters the combustion chamber 202, heats up to 1100°C, and stays in the temperature range of 1100°C for 2s to ensure pyrolysis in the thermal kiln 102 The gas compounds generated are completely harmless and decomposed; the combustion chamber 202 is heated by natural gas, the combustion temperature is controlled by adjusting the flow of natural gas, and the oxygen content in the flue gas is controlled by adjusting the fresh air volume.

The flue gas produced by the combustion chamber 202 enters the flue gas purification device 203, and the flue gas purification device 203 includes: semi-dry quenching deacidification tower, SNCR, bag filter 201, flue gas condenser and flue gas heat exchanger, After heat exchange by the flue gas heat exchanger, the temperature of the flue gas entering the induced draft fan 205 or the circulating fan 204 is 200°C, that is, the flue gas after the flue gas purification device 203 is divided into two paths, one path enters the thermal kiln 102 through the circulating fan 204, Recirculation of the flue gas is realized, and the other path is exhausted through the induced draft fan 205 and the chimney 206 after reaching the standard. The emission index of the flue gas discharged through the chimney 206 meets the requirements of "GB18484 Hazardous Waste Incineration Pollution Control Standard".

Among them, the condenser can reduce the water vapor content in the circulating flue gas.

Further, an electric heater 1023 is installed on the thermal kiln 102, and the electric heater 1023 is divided into three independent circuits, as shown in FIG. The control accuracy is ±5°C.

Further, the kiln head of the thermal kiln 102 is provided with a humidifying water atomization spray gun and a water flow control circuit, which are used to control the water volume of the thermal kiln 102 according to the actual organic matter removal effect in the organic waste salt.

Further, the kiln head of the thermal kiln 102 is provided with a nitrogen nozzle and a nitrogen flow control circuit, which are used to control the amount of nitrogen in the thermal kiln 102 according to the actual organic matter removal effect in the organic waste salt.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (7)

1. A method that adopts double-cycle thermal purification technology to process waste salt containing organic matter, is characterized in that, the method comprises: Organic waste salt is decomposed into purified industrial waste salt and flue gas after entering the thermal kiln through the feed bin; The purified industrial waste salt is divided into two paths after entering the intermediate bin, and one path is recirculated into the feed bin through the frequency conversion return conveying system, and mixed with the untreated organic waste salt in the feed bin, together Enter the thermal kiln again, and discharge outwards through the finished product warehouse all the way; The flue gas is divided into two paths after dust removal, combustion and purification, one path is circulated to the thermal kiln, and the other path is discharged; the organic waste salt needs to be pretreated before entering the feeding bin, and then passed through the The feed bin enters the thermal kiln and stays in the thermal kiln for 30-120 minutes, and the organic matter in the organic waste salt is thermally decomposed into the flue gas and the purified industrial waste salt; The circulating flue gas enters the kiln tail of the thermal kiln tangentially, and the circulating flue gas enters tangentially from the kiln tail of the thermal kiln at 270°. 2. The method for treating waste salt containing organic matter by adopting double-cycle thermal purification technology according to claim 1, characterized in that, the thermal kiln adopts a rotary thermal kiln with an inclination angle of 2°-5°, and the thermal kiln is 360 degrees rotation. 3. The method for treating waste salt containing organic matter by adopting double-cycle thermal purification technology according to claim 2, characterized in that, the thermal kiln is driven to rotate by a rotating motor, and the frequency of the rotating motor is changed to adjust the waste organic matter. Residence time of salt in the thermal kiln. 4. The method for treating waste salt containing organic matter using double-cycle thermal purification technology according to claim 2, characterized in that the temperature of the thermal kiln is adjustable within the range of 300°C-600°C, and the temperature can be adjusted by changing The power of the heating device of the thermal kiln, the combustion temperature of the flue gas and the flow rate of the circulating flue gas. 5. The method for treating waste salt containing organic matter using double-cycle thermal purification technology according to claim 1, characterized in that the kiln hood of the thermal kiln adopts a sinking structure to separate the purified industrial waste salt and the smoke gas. 6. A system for treating waste salt containing organic matter using dual-cycle thermal purification technology, characterized in that it includes a waste organic salt treatment system and a flue gas treatment system, wherein: The organic waste salt treatment system includes a feed bin, a thermal kiln for decomposing organic waste salt, an intermediate bin, a finished product bin, and a return conveying system. The feed bin, the thermal kiln, the intermediate bin, and the The finished product bins are connected end to end and communicated in sequence. The thermal kiln decomposes the organic waste salt to form purified industrial waste salt and flue gas. The thermal kiln is connected and communicated with the feed bin through the return conveying system at the same time. The purified industrial waste salt flows back to the feed bin through the return conveying system all the way, and discharges outward through the finished product bin all the way; The flue gas treatment system is connected and communicated with the thermal kiln, and the flue gas is discharged from the thermal kiln and treated by the flue gas treatment system, then circulates to the thermal kiln all the way, and discharges all the way to the outside; The flue gas treatment system includes a dust collector, a combustion chamber, a flue gas purification device and a circulating fan, the dust collector is connected and communicated with the thermal kiln, the dust collector, the combustion chamber, the flue gas purification device And the circulation fan is connected end to end in sequence, the flue gas is discharged from the thermal kiln and passes through the dust collector successively for dust removal, after the combustion chamber is burned and the flue gas purification device is purified, it is circulated by the circulation fan to the Describe thermal kiln. 7. The system for treating waste salts containing organic matter using dual-cycle thermal purification technology according to claim 6, characterized in that it also includes an induced draft fan and a chimney, and the induced draft fan is simultaneously connected with the chimney and the flue gas purification device Connected, the induced draft fan is used to discharge the up-to-standard flue gas purified by the flue gas purification device.

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