A desulfurized ash recycling device and method

Abstract

The application discloses a desulfurization ash recycling device and method, and relates to the technical field of solid waste resource utilization, which comprises a raw material bin for storing desulfurization ash, a feeding pipeline, a first air flow classifier for primary air separation of the desulfurization ash, a second air flow classifier for secondary air separation of the desulfurization ash and a fifth steel bin, the first air flow classifier is further communicated with a first steel bin, the second air flow classifier is further communicated with a fourth steel bin, the feeding pipeline, the first air flow classifier and the second air flow classifier are all communicated with a hot air pipeline, the desulfurization ash is air separated through the first air flow classifier and the second air flow classifier, different mesh desulfurization ash is fully utilized, the desulfurization ash is blown through hot air, dihydrate gypsum in the desulfurization ash is converted into hemihydrate gypsum, the air-separated desulfurization ash has qualified strength when used for producing putty powder without additional cementing material, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of solid waste resource utilization technology, specifically to a desulfurization ash recycling device and method. Background Technology

[0002] In float glass production, flue gas desulfurization technology has been widely adopted. Semi-dry desulfurization technology, with its advantages of low equipment investment, low operating costs, small footprint, simple maintenance, and low wastewater discharge, has become the future trend of flue gas desulfurization technology in glass factories. This type of process uses powdered calcium-based absorbents to remove SO2 from the flue gas. The desulfurization product is dry powdered desulfurization ash, mainly composed of calcium sulfite hemihydrate (CaSO3·1 / 2H2O), calcium sulfate (CaSO4·2H2O), calcium carbonate (CaCO3), and unreacted calcium hydroxide (Ca(OH)2), etc. The desulfurization ash contains 20-30% calcium carbonate, 30-40% calcium sulfate, 20-30% calcium sulfite, and ≤10% calcium hydroxide. Compared with wet processes, the desulfurization ash produced by semi-dry processes has a much more complex composition, characterized by high sulfur, high calcium, and high alkalinity.

[0003] Because research on the properties, reaction characteristics, and mechanisms of action of semi-dry desulfurization ash is not yet systematic and in-depth, people currently hold a cautious attitude towards its comprehensive utilization, and no effective utilization pathways have been formed. This has led to the large-scale accumulation or simple landfilling of semi-dry desulfurization ash, which not only occupies a large amount of valuable land resources but also increases the burden on enterprises. In addition, long-term stockpiling can easily cause the release of sulfur dioxide (SO2), posing a potential threat to the environment; at the same time, due to the small particle size and light weight of the desulfurization ash, the stockpile site is very prone to dust pollution.

[0004] Therefore, it is necessary to develop and design desulfurization ash recycling devices and methods to fully utilize desulfurization ash and avoid environmental pollution, which is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a desulfurization ash recycling device and method. By performing multi-level grading and sorting of the desulfurization ash, the device and method fully utilize the ash to produce rubber and plastic fillers and building coatings, thereby avoiding environmental pollution.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] A desulfurization ash recycling device includes a raw material silo for storing desulfurization ash, a feed pipe, a No. 1 air classifier for primary air separation of the desulfurization ash, a No. 2 air classifier for secondary air separation of the desulfurization ash, and a No. 5 steel silo, which are connected in sequence. The No. 1 air classifier is also connected to the No. 1 steel silo, and the No. 2 air classifier is also connected to the No. 4 steel silo. The feed pipe, the No. 1 air classifier, and the No. 2 air classifier are all connected to a hot air pipe.

[0008] Preferably, a fan for conveying hot air is installed on the connecting pipes between the hot air duct and the feed duct, the No. 1 air classifier and the No. 2 air classifier.

[0009] Preferably, the No. 1 steel silo is connected to the circulating ash system, or the No. 1 steel silo is connected to the circulating ash system sequentially through a crusher and a No. 2 steel silo.

[0010] Preferably, the No. 5 steel silo is connected to a ton bagging machine for packaging the products stored in the No. 5 steel silo, a bagging machine for packaging the products stored in the No. 5 steel silo, and a canning machine for packaging the products stored in the No. 5 steel silo.

[0011] Preferably, both the No. 1 air classifier and the No. 2 air classifier are equipped with sampling devices for material sampling and analysis on their discharge pipes.

[0012] This invention also discloses a method for recycling desulfurization ash, using the desulfurization ash recycling device described above, comprising the following steps:

[0013] The desulfurization ash enters the feed pipe with hot air from the raw material silo, and the water and crystal water in the desulfurization ash are removed;

[0014] The desulfurization ash is air-separated by the No. 1 air classifier. Coarse particles smaller than 300 mesh enter the No. 1 steel silo, while fine particles of 300 mesh and above enter the No. 2 air classifier for air separation.

[0015] The coarse particles smaller than 1250 mesh separated by the No. 2 air classifier enter the No. 4 steel silo as paper filling material, for the production of building coatings or putty powder, while the fine powder of 1250 mesh and above separated by the No. 2 air classifier enters the No. 5 steel silo as rubber and plastic filling material.

[0016] Preferably, the feed pipe, the first air classifier, and the second air classifier are all purged with hot air, and the temperature of the second air classifier is higher than that of the first air classifier, and the temperature of the first air classifier is higher than that of the feed pipe.

[0017] Preferably, after the desulfurization ash passes through the feed pipe, the No. 1 air classifier, and the No. 2 air classifier, the hot air converts the dihydrate gypsum in the desulfurization ash into hemihydrate gypsum.

[0018] Preferably, the hot air temperature is between 250 degrees Celsius and 300 degrees Celsius.

[0019] Preferably, the mesh size of the output material from the No. 1 air classifier and the No. 2 air classifier can be adjusted by regulating the air volume and speed of the fan.

[0020] The present invention achieves the following technical effects compared to the prior art:

[0021] By using the No. 1 and No. 2 air classifiers to classify desulfurization ash, the desulfurization ash of different mesh sizes can be fully utilized, avoiding the environmental pollution caused by the arbitrary landfilling and discharge of desulfurization ash. Furthermore, by using hot air to purge the desulfurization ash, the dihydrate gypsum in the desulfurization ash is converted into hemihydrate gypsum, so that the air-classified desulfurization ash can be used to produce putty powder without the need for the addition of external cementing materials, thus reducing production costs. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Appendix Figure 1 This is a schematic diagram of the overall structure of the desulfurization ash recycling device disclosed in this invention. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] The purpose of this invention is to provide a device and method for recycling desulfurization ash, which achieves full utilization of desulfurization ash through multi-level grading and sorting to produce rubber and plastic fillers and building coatings, thereby avoiding environmental pollution.

[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] refer to Figure 1 The desulfurization ash recycling device disclosed in this embodiment of the invention includes at least a raw material silo containing desulfurization ash. The raw material silo is connected to a feed pipe via an airlock, a screw feeder, and a collection hopper. The feed pipe is connected to a hot air pipe, which provides hot air to the feed pipe, causing the desulfurization ash to be heated in the feed pipe to remove attached water and some crystal water. The feed pipe is connected to a first air classifier, which is connected to a first steel silo and a second air classifier. The first air classifier separates the desulfurization ash by air separation, conveying coarse particles with a mesh size less than 300 to the first steel silo, while fine particles with a mesh size greater than or equal to 300 enter the second air classifier. Both the first and second air classifiers are connected to the hot air pipe, and the ash is heated by the hot air in the hot air pipe. The blowing of air can prevent the desulfurization ash from sticking to the inner wall of the No. 1 and No. 2 air classifiers (because as the desulfurization ash is conveyed from the feed pipe to the No. 1 and then to the No. 2 air classifiers, the temperature will gradually decrease and the humidity will gradually increase. If the inside of the No. 1 and No. 2 air classifiers is not purged with hot air, the desulfurization ash will inevitably stick to the inside of the No. 1 and No. 2 air classifiers). The No. 2 air classifier continues to be air-separated. The No. 2 air classifier is connected to the No. 4 and No. 5 steel bins respectively. Fine powder with a mesh size of 1250 mesh or greater enters the No. 5 steel bin as a high-quality filler in the plastics and rubber industries, and coarse particles with a mesh size of less than 1250 mesh enter the No. 4 steel bin as a paper filling material or for the production of building coatings and putty powder.

[0028] This embodiment utilizes air classification of desulfurization ash using a No. 1 and No. 2 air classifier to fully utilize desulfurization ash of different particle sizes, avoiding environmental pollution caused by arbitrary landfilling and discharge of desulfurization ash. Furthermore, by purging with hot air, the dihydrate gypsum in the desulfurization ash is converted into hemihydrate gypsum, so that the air-classified desulfurization ash can achieve qualified strength without the addition of external cementing materials when used to produce putty powder, thus reducing production costs.

[0029] It should be noted that the No. 1 air classifier and the No. 1 steel silo are connected by an air lock and a conveying pump to transport materials. In addition, compressed gas is introduced during the conveying process to provide power for the material transport.

[0030] A sampling device is installed on the discharge pipe at the front end of No. 4 steel silo, which can be used to sample and analyze the materials entering No. 4 steel silo.

[0031] refer to Figure 1In one embodiment, a fan for conveying hot air is installed on each of the connecting pipes between the hot air duct and the feed duct, the No. 1 air classifier and the No. 2 air classifier. That is, a fan is installed on each connecting pipe. By adjusting the wind speed and flow rate of each fan, the mesh size of the material output by the No. 1 air classifier and the No. 2 air classifier can be adjusted respectively.

[0032] refer to Figure 1 As a preferred method, the No. 1 steel silo is connected to the circulating ash system, or the No. 1 steel silo is connected to the circulating ash system sequentially through a crusher and the No. 2 steel silo. This is because the No. 1 steel silo stores coarse particles with a mesh size of less than 300 mesh, while the calcium hydroxide (desulfurizing agent) in the desulfurization ash will be enriched in coarse particles with a mesh size of less than 300 mesh (content exceeding 20%). Therefore, the coarse particles in the No. 1 steel silo can be transported to the circulating ash system as desulfurizing agent recycling material, which can save 10% of the desulfurizing agent. Alternatively, the coarse particles in the No. 1 steel silo can be crushed by a crusher and then transported to the No. 2 steel silo, and then transported to the circulating ash system for reuse.

[0033] It should be noted that the circulating ash system uses dry spraying of calcium-based absorbent (such as limestone powder or hydrated lime) to react with SO2 in the flue gas to generate solid desulfurization ash such as calcium sulfate (CaSO4). In other words, the circulating ash system is a device for generating desulfurization ash. The desulfurization ash generated by the circulating ash system is transported to the raw material silo. In this embodiment, desulfurization ash below 300 mesh is reused, which can reduce the use of desulfurizing agent in the circulating ash system.

[0034] A sampling device is installed on the discharge pipe at the front end of the No. 1 steel silo. The particle size of the material entering the No. 1 steel silo is analyzed by the sampling device. If the particle size is small, it can be directly fed into the circulating ash system and used as a desulfurizing agent. If the particle size is large, it is crushed by a crusher and then transported to the No. 2 steel silo and then to the circulating ash system for use as a desulfurizing agent.

[0035] refer to Figure 1In one embodiment, steel silo No. 5 is connected to a ton bagging machine, a packaging machine, and steel silo No. 3. A screw feeder is installed between steel silo No. 5 and the ton bagging machine to transport materials. The ton bagging machine packages the products stored in steel silo No. 5 into ton bags. During the ton bagging process, a bag filter dust collector removes dust. After ton bagging is completed, the packaged products are stored in the warehouse via a belt conveyor. A screw feeder is also installed between steel silo No. 5 and the packaging machine to transport materials. The packaging machine packages the products in steel silo No. 5 into 2-ton bags. The products are packed in 0 kg bags and then transported by a conveyor system. They are then palletized by robots and stored in the warehouse. During the packaging process, dust is removed by a bag filter. An airlock is installed between steel silos No. 5 and No. 3 to ensure continuous material flow. When products from steel silo No. 5 are transported to steel silo No. 3 (which can be connected to a tank truck), they are simultaneously treated by a bag filter and a centrifugal fan. When the products are canned into steel silo No. 3, they are also treated by a fan and a dust collector to prevent dust from being generated in the workshop.

[0036] This invention also discloses a method for recycling desulfurization ash, using the desulfurization ash recycling device described above, comprising the following steps:

[0037] The desulfurization ash enters the feed pipe with hot air from the raw material silo, and the water and crystal water in the desulfurization ash are removed.

[0038] The desulfurization ash is air-separated by the No. 1 air classifier. Coarse particles smaller than 300 mesh enter the No. 1 steel silo, while fine particles of 300 mesh and above enter the No. 2 air classifier for air separation.

[0039] Coarse particles smaller than 1250 mesh, separated by the No. 2 air classifier, enter the No. 4 steel silo as paper filling material, for the production of building coatings or putty powder. Fine powder of 1250 mesh and above, separated by the No. 2 air classifier, enters the No. 5 steel silo as rubber and plastic filling material.

[0040] refer to Figure 1 As a preferred method, the feed pipe, the No. 1 air classifier, and the No. 2 air classifier are all purged with hot air, and the temperature of the No. 2 air classifier is ensured to be higher than that of the No. 1 air classifier, and the temperature of the No. 1 air classifier is higher than that of the feed pipe. By ensuring that the temperature of the desulfurization ash material increases as it is conveyed along the feed pipe, the No. 1 air classifier, and the No. 2 air classifier, the problem of the desulfurization ash sticking to the inner walls of the No. 1 and No. 2 air classifiers due to increased humidity during the conveying process can be effectively avoided, thus ensuring the normal conveying of the desulfurization ash.

[0041] refer to Figure 1As one implementation method, after passing through the feed pipe, the No. 1 air classifier and the No. 2 air classifier, the hot air converts the dihydrate gypsum in the desulfurization ash into hemihydrate gypsum, so that the desulfurization ash from air classification can have qualified strength without the addition of external cementing materials when used to produce putty powder, thus reducing production costs.

[0042] refer to Figure 1 As one implementation method, the hot air temperature is 250 to 300 degrees Celsius. On the one hand, this is to ensure that the desulfurization ash removes the attached water and some of the crystal water in the feed pipe. On the other hand, the temperature range for the conversion of dihydrate gypsum to hemihydrate gypsum is 107 to 170 degrees Celsius. Therefore, setting the hot air temperature to 250 to 300 degrees Celsius is to maximize the conversion of dihydrate gypsum to hemihydrate gypsum. At this temperature, some dihydrate gypsum will be converted into type III anhydrous gypsum, which will be further homogenized in the 150-degree Celsius insulated tank, eventually generating more hemihydrate gypsum.

[0043] refer to Figure 1 As one implementation method, the mesh size of the materials conveyed by the No. 1 and No. 2 air classifiers can be adjusted by regulating the air volume and speed of the fans, so that products of different specifications can be obtained at the same time to meet the needs of different users.

[0044] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A desulfurization ash recycling device, characterized in that, The system includes a raw material silo for storing desulfurization ash, a feed pipeline, a No. 1 air classifier for primary air separation of the desulfurization ash, a No. 2 air classifier for secondary air separation of the desulfurization ash, and a No. 5 steel silo, which are connected in sequence. The No. 1 air classifier is also connected to the No. 1 steel silo, and the No. 2 air classifier is also connected to the No. 4 steel silo. The feed pipeline, the No. 1 air classifier, and the No. 2 air classifier are all connected to a hot air pipeline. The No. 1 steel silo is connected to the circulating ash system, and the desulfurization ash generated by the circulating ash system is transported to the raw material silo. The temperature of the No. 2 air classifier is greater than that of the No. 1 air classifier, and the temperature of the No. 1 air classifier is greater than that of the feed pipe. The No. 2 air classifier is connected to the No. 4 and No. 5 steel bins respectively. Fine powder with a mesh size of 1250 or greater enters the No. 5 steel bin as a high-quality filler for the plastics and rubber industries, while coarse particles with a mesh size of less than 1250 enter the No. 4 steel bin as a papermaking filler or for the production of building coatings and putty powder. After passing through the feed pipe, the No. 1 air classifier, and the No. 2 air classifier, the hot air converts the dihydrate gypsum in the desulfurization ash into hemihydrate gypsum. The desulfurization ash is air-separated by the No. 1 air classifier. Coarse particles smaller than 300 mesh enter the No. 1 steel silo, while fine particles of 300 mesh and above enter the No. 2 air classifier for air separation.

2. The desulfurization ash recycling device according to claim 1, characterized in that, Each of the hot air ducts and the connecting pipes of the feed duct, the No. 1 air classifier, and the No. 2 air classifier is equipped with a fan for conveying hot air.

3. The desulfurization ash recycling device according to claim 1, characterized in that, Alternatively, the No. 1 steel silo can be connected to the circulating ash system via a crusher and the No. 2 steel silo in sequence.

4. The desulfurization ash recycling device according to claim 1, characterized in that, The No. 5 steel silo is connected to a ton bagging machine for packaging the products stored in the No. 5 steel silo, a bagging machine for packaging the products stored in the No. 5 steel silo, and a canning machine for packaging the products stored in the No. 5 steel silo.

5. The desulfurization ash recycling device according to claim 1, characterized in that, Both the No. 1 and No. 2 air classifiers are equipped with sampling devices for material sampling and analysis on their discharge pipes.

6. The desulfurization ash recycling device according to claim 1, characterized in that, The temperature of the hot air is between 250 and 300 degrees Celsius.

7. The desulfurization ash recovery and utilization device according to claim 1, characterized in that, The mesh size of the output material from the No. 1 and No. 2 air classifiers can be adjusted by regulating the air volume and speed of the blower.

Images