Industrial waste salt continuous incineration recycling device

Abstract

The utility model discloses an industrial waste salt continuous incineration recycling device which comprises a tubular multi-stage incineration tower and an elevator, the upper end of the elevator is communicated with a feeding machine through an elevator salt outlet, the lower end of the feeding machine is communicated with the tubular multi-stage incineration tower, the bottom of the tubular multi-stage incineration tower is communicated with a slag cooler, and the slag cooler is communicated with a slag outlet of the elevator. The lower end of the slag cooler is communicated with a two-way conveyor, the side end of the two-way conveyor is communicated with a stock bin, the other side of the two-way conveyor is communicated with an elevator salt inlet, a strong brine spraying inlet is formed in the middle of the tubular multi-stage incineration tower, and a natural gas burner is arranged at the symmetrical position of the strong brine spraying inlet. According to the continuous incineration recycling device for the industrial waste salt, the purpose of treating the industrial waste salt is achieved through the arrangement of the structure.

Description

Technical Field

[0001] The utility model relates to the technical field of waste salt disposal equipment, in particular to a device for continuous incineration and recycling of industrial waste salt. Background Art

[0002] Industrial waste salt comes from industrial production. High-salt wastewater treatment and pesticide production will produce a large amount of industrial waste salt, which mainly refers to solid waste with inorganic salt as the main component. The annual output of waste salt exceeds 2.0x107t, which is mainly divided into two categories: sodium chloride and sodium sulfate. According to the industry, it is divided into pesticide industry (30%), medicine (10%), fine chemicals (15%), printing and dyeing (45%).

[0003] Industrial waste salt has the characteristics of complex composition, wide sources and high toxicity. Although it is not listed separately in the list of hazardous wastes, the 2016 National List of Hazardous Wastes clearly defines distillation and reaction residues, waste mother liquor and reaction-based wastes generated in the production of chemical synthesis APIs as hazardous wastes. Therefore, industrial waste salt not only damages the ecological environment and harms humans and animals, but once the soluble salts and impurities in the waste salt cause serious soil salinization, it will endanger the survival and development of surrounding agriculture, forestry and animal husbandry, and even cause serious pollution to surrounding water sources and groundwater, which is extremely harmful.

[0004] Fine chemicals: one of the main industries that produces industrial waste salt. In this industry, waste salt is mainly produced from byproducts of chemical reactions, wastewater and waste residues. The characteristics of the fine chemical industry are that the raw materials used in the production process are various and the chemical reactions are complex. The organic matter in the waste salt cannot be reused in industrial production. These substances are very harmful to the environment and human health. For the treatment and disposal of waste salt in the fine chemical industry, a series of measures need to be taken.

[0005] 2. Existing Technology

[0006] The existing incineration technologies mainly include rotary kiln incineration method, fluidized bed incineration method (CN111167841A) and hot air furnace continuous incineration method (patent CN106949482 A).

[0007] Rotary kiln incineration method: The tubular multi-stage incineration tower (1) controls the flue gas temperature of the rotary kiln to 750°C and the outlet flue gas temperature to 400°C; the waste salt in the rotary kiln is discharged from the kiln tail after being subjected to high-temperature oxidation treatment at 750°C. Elevator (2) Secondary combustion chamber: The temperature of the secondary combustion furnace is controlled at above 1100°C, and the flue gas residence time is more than 2s, which can fully decompose harmful odors and polychlorinated compounds and inhibit the formation of dioxins. Secondary combustion chamber (3) Combustion-supporting system: By controlling the amount of natural gas injection, the system is slowly heated to normal operating conditions to maintain normal operation of the system. Rapid cooler (4) Air supply system: The primary air is replenished from the kiln tail, mixed with the incineration flue gas and then enters the rotary kiln; the secondary air is replenished from the secondary chamber. Water supply system (5) Flue gas purification system, through the desulfurization, denitrification and dust removal of the flue gas, after meeting the emission conditions, it is discharged into the atmosphere through the chimney.

[0008] Fluidized bed incineration method: After the waste salt is dried by a drum dryer, it is broken into waste salt particles of appropriate particle size by a crushing and screening machine, and enters the fluidized bed suspension layer. After fluidization with steam, combustion-supporting gas and air, it undergoes high turbulence and mixing, and is discharged after staying for a certain period of time. The stripped VOC organic matter and the VOC tail gas generated by drying enter the secondary combustion chamber for full combustion, and finally are discharged after cooling and purification. This method can continuously process industrial waste salt in large quantities.

[0009] Hot air furnace continuous incineration method: In the continuous incineration process, a vertical grinder is added to break the waste salt particles and grind them into powder. Then, hot air is used to carry the waste salt powder into the incinerator for full combustion. Thus, the pollutants in the solid waste salt are completely decomposed and destroyed. The hot air carries the powder into the incinerator for transportation, so that the hot air and the waste salt powder do not need to be separated and can enter the incinerator in one step.

[0010] 1. The disadvantages of the rotary kiln incineration method are: the alkali metal salts in the waste salt of the tubular multi-stage incineration tower (1) are heated to a molten state, and the molten alkali metal salts will corrode the refractory lining of the rotary kiln. During the operation of the rotary kiln, the alkali metal salts adhering to the refractory bricks will cause corrosion to the refractory bricks at the adhesion point and further corrode the inside of the refractory bricks, shortening the service life of the refractory bricks. During the operation of the rotary kiln, the refractory bricks will fall off due to corrosion, which will lead to shutdown. The cost of updating and replacing refractory bricks is the main operating cost of the high-temperature rotary kiln hazardous waste disposal system; the removal rate of the elevator (2) is difficult to meet the increasingly stringent hazardous waste treatment requirements, and the waste salt is difficult to be delivered to the rotary kiln in small and uniform particles. The temperature in the kiln is difficult to control, resulting in high local temperatures and high concentrations of harmful substances such as nitrogen oxides and dioxins in the exhaust gas.

[0011] 2. The disadvantages of the fluidized bed incineration method are: the treatment of waste salt by the tubular multi-stage incinerator (1) is also affected by the alkali metal salt in the waste salt. The presence of molten alkali metal salt in the fluidized bed furnace can easily cause slagging of the bed material, resulting in failure of fluidization of the bed material and shutdown of the furnace; the elevator (2) has certain requirements on the particle size of the waste salt. If the particle size is too large, the oxidation time of the waste salt in the fluidized bed incinerator is short, the incineration is not sufficient, and the harmful substances cannot be fully analyzed, resulting in incomplete treatment; if the particle size is too small, it is easy to be directly brought into the secondary combustion chamber under the action of the fluidizing wind, and the alkali metal salt melts under the action of high temperature, affecting the normal use of the refractory material.

[0012] 3. The disadvantages of the hot air furnace continuous incineration method are: the tubular multi-stage incineration tower (1) needs to be designed with a hot air furnace, which consumes a lot of energy during operation and has high operating costs; the elevator (2) needs to be designed with a waste salt grinding device, which has requirements for the particle size of the waste salt. The waste salt must be ground into powder and sprayed into the incinerator together with the hot air. Waste salt with large particle size needs to be ground multiple times to meet the requirements. Utility Model Content

[0013] The purpose of the utility model is to provide a device for continuous incineration and recycling of industrial waste salt to solve the problems raised in the above background technology.

[0014] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a device for continuous incineration and recycling of industrial waste salt, comprising a tubular multi-stage incineration tower and an elevator, wherein the upper end of the elevator is connected to a feeder through a salt outlet of the elevator, the lower end of the feeder is connected to a tubular multi-stage incineration tower, the bottom of the tubular multi-stage incineration tower is connected to a slag cooler, the lower end of the slag cooler is connected to a two-way conveyor, the side end of the two-way conveyor is connected to a silo, the other side of the two-way conveyor is connected to a salt inlet of the elevator, a concentrated brine injection port is provided at the middle position of the tubular multi-stage incineration tower, and a natural gas burner is provided at a symmetrical position of the concentrated brine injection port;

[0015] The top of the tubular multi-stage incineration tower is connected to a secondary combustion chamber, a secondary combustion chamber natural gas burner is installed at the upper end of the secondary combustion chamber, a rapid cooler is provided at the lower end of the secondary combustion chamber, and a water supply system is connected to the rapid cooler, a side end of the rapid cooler is connected to an induced draft fan through a dust collector, a side end of the induced draft fan is connected to a desulfurization system, and the induced draft fan is also connected to a flue gas circulation system, and the flue gas circulation system is connected to the secondary combustion chamber.

[0016] Specifically, the rapid cooler includes an evaporator, an economizer, a desalted water inlet and a steam outlet. The upper end of the desalted water inlet is connected to the steam outlet through the evaporator, and the economizer is provided at the bottom of the evaporator.

[0017] Specifically, the silo is connected to the elevator through a bidirectional conveyor, and the elevator is connected to the feeder through the elevator salt outlet.

[0018] Specifically, the bidirectional conveyor can perform bidirectional transmission work.

[0019] Specifically, the tubular multi-stage incineration tower is a circumferential body and is heated by natural gas.

[0020] Specifically, the rapid cooler is a vertical water tube waste heat boiler, and the inlet section adopts a wide-pitch steam-water film screen.

[0021] Compared with the prior art, the beneficial effects of the utility model are:

[0022] 1. The process system can automatically screen the waste salt and incinerate it using different processes to achieve complete harmless treatment. (Most granular waste salt enters the top of the tubular multi-stage incinerator, forms convection with the flue gas from top to bottom and is discharged at the bottom. After the waste salt is discharged, it is lifted to the top entrance again by the lifting mechanism, and this is repeated to ensure that the difficult-to-burn organic matter is fully analyzed; liquid concentrated brine enters the tubular multi-stage incinerator from the spray inlet, and the water evaporates less at high temperature, and the salt volatilizes and enters the secondary combustion chamber with the flue gas; a small number of waste salts with very small particle size (fine powder) enter the high temperature area of ​​the secondary combustion chamber with the high temperature flue gas. The temperature is above 1100℃. The waste salt with small particle size (fine powder) can be directly incinerated at high temperature at this temperature to reach a molten state and completely decompose the organic matter;)

[0023] 2. 95% of the waste salt is incinerated at a temperature of about 700-800℃. At this temperature, the alkali metal salts in the waste salt cannot reach a molten state, which minimizes the corrosion of the alkali metal salts on the refractory materials of the incineration equipment and improves the operating efficiency of the equipment.

[0024] 3. The entire process requires fewer devices and has low operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the main structure of the utility model;

[0026] Figure 2 This is a structural diagram of the rapid cooler of the utility model.

[0027] In the figure: 1: tubular multi-stage incineration tower; 1-1-1: feeder; 1-2-1: natural gas burner; 1-3-1: blower; 1-4-1: slag cooler; 1-5-1: bidirectional conveyor;

[0028] 2: elevator; 2-1-1: elevator salt inlet; 2-2-1: elevator salt outlet;

[0029] 3: Second combustion chamber; 3-1-1: Second combustion chamber natural gas burner;

[0030] 4: Rapid cooler; 4-1-1: Evaporator; 4-1-2: Economizer; 4-2-1: Demineralized water inlet; 4-2-2: Steam outlet;

[0031] 5: Water supply system; 6: Dust collector; 7: Draft fan; 7-1-1: Flue gas circulation system; 8: Desulfurization system; 9: Silo; 10: Brine injection port. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0033] See also Figure 1-2 The utility model provides a technical solution: a device for continuous incineration and recycling of industrial waste salt, comprising a tubular multi-stage incineration tower 1 and an elevator 2, wherein the upper end of the elevator 2 is connected to a feeder 1-1-1 through an elevator salt outlet 2-2-1, and the lower end of the feeder 1-1-1 is connected to a tubular multi-stage incineration tower 1, and the bottom of the tubular multi-stage incineration tower 1 is connected to a slag cooler 1-4-1, and the lower end of the slag cooler 1-4-1 is connected to a two-way conveyor 1-5-1, and the side end of the two-way conveyor 1-5-1 is connected to a silo 9, and the other side of the two-way conveyor 1-5-1 is connected to a elevator salt inlet 2-1-1, and a concentrated brine injection port 10 is provided in the middle of the tubular multi-stage incineration tower 1, and a natural gas burner 1-2-1 is provided at a symmetrical position of the concentrated brine injection port 10;

[0034] The top of the tubular multi-stage incineration tower 1 is connected to a secondary combustion chamber 3, a secondary combustion chamber natural gas burner 3-1-1 is installed at the upper end of the secondary combustion chamber 3, a rapid cooler 4 is provided at the lower end of the secondary combustion chamber 3, and a water supply system 5 is connected to the rapid cooler 4, a side end of the rapid cooler 4 is connected to an induced draft fan 7 through a dust collector 6, a side end of the induced draft fan 7 is connected to a desulfurization system 8, and the induced draft fan 7 is also connected to a flue gas circulation system 7-1-1, and the flue gas circulation system 7-1-1 is connected to the secondary combustion chamber 3.

[0035] The rapid cooler 4 includes an evaporator 4-1-1, an economizer 4-1-2, a desalted water inlet 4-2-1 and a steam outlet 4-2-2. The upper end of the desalted water inlet 4-2-1 is connected to the steam outlet 4-2-2 through the evaporator 4-1-1, and the economizer 4-1-2 is provided at the bottom of the evaporator 4-1-1.

[0036] The silo 9 is connected to the elevator 2 through the bidirectional conveyor 1-5-1, and the elevator 2 is connected to the feeder 1-1-1 through the elevator salt outlet 2-2-1.

[0037] The bidirectional conveyor 1-5-1 is capable of bidirectional transmission.

[0038] The tubular multi-stage incineration tower 1 is a circumferential body and is heated by natural gas.

[0039] The rapid cooler 4 is a vertical water-tube waste heat boiler, and the inlet section adopts a wide-pitch steam-water film screen.

[0040] The waste salt to be treated enters the elevator through the elevator salt inlet and is lifted to the salt outlet. The elevator salt outlet is connected to the feeder inlet, and the waste salt enters the tubular multi-stage incineration tower evenly through the feeder; the concentrated brine liquid to be treated enters the tubular multi-stage incineration tower from the concentrated brine spray inlet in the middle and upper part;

[0041] Waste salt enters from the upper part of the tubular multi-stage incinerator and is discharged from the lower part. The upper part of the tubular multi-stage incinerator is the incineration section with a temperature of 750-850℃. At this temperature, waste salt can effectively precipitate organic matter.

[0042] After most of the waste salt precipitates organic matter, it falls to the cooling section at the bottom of the tubular multi-stage incinerator under the action of its own gravity. The temperature of the cooling section is 200-400℃. After the temperature drops, it is further cooled to below 50℃ by the slag cooler at the bottom of the tubular multi-stage incinerator.

[0043] The inlet of the slag cooler is connected to the bottom outlet of the tubular multi-stage incineration tower, and the outlet of the slag cooler is connected to the inlet of the bidirectional conveyor;

[0044] The cooled waste salt enters the elevator through the bidirectional conveyor, and is then sent to the feeder again through the elevator. It then evenly enters the tubular multi-stage incineration tower through the feeder and is incinerated again. This cycle of incineration is repeated until the organic matter is completely precipitated, thus achieving the purpose of completely removing the organic matter. When the organic matter in the waste salt is completely removed, the bidirectional conveyor will run in the reverse direction, and the incinerated waste salt will be sent to the silo for storage, so that it can be recycled by users.

[0045] The bidirectional conveyor has two outlets, one outlet is connected to the elevator and the other outlet is connected to the silo;

[0046] A small number of waste salts with very small particle sizes (fine powder) do not have time to precipitate organic matter in the incineration section at the top of the tubular multi-stage incineration tower, and enter the secondary combustion chamber along with the high-temperature flue gas. The upper flue gas outlet of the tubular multi-stage incineration tower is connected to the inlet of the secondary combustion chamber; the temperature in the high-temperature area of ​​the secondary combustion chamber is above 1100°C, and waste salts with small particle sizes (fine powder) can be directly incinerated at high temperature at this temperature to reach a molten state and completely decompose organic matter; the completely incinerated waste salt is cooled to below 700°C by the circulating flue gas at the bottom of the secondary combustion chamber, crystallized into particles, and finally settled into the hopper at the bottom of the rapid cooler, and sent to the silo after a short storage; the lower outlet of the secondary combustion chamber is connected to the rapid cooler;

[0047] The organic matter precipitated in the incineration section of the tubular multi-stage incinerator also enters the secondary combustion chamber along with the high-temperature flue gas, where it is completely decomposed under the high-temperature state of the secondary combustion chamber. All organic matter is finally decomposed into CO2 and H2O, and enters the next process along with the high-temperature flue gas.

[0048] Industrial waste salt is incinerated in different ways in the above two areas, and the organic matter in it is completely precipitated and thoroughly decomposed;

[0049] 2. Flue gas flow:

[0050] The upper part of the tubular multi-stage incineration tower is provided with a high-temperature flue gas outlet, which is connected to the secondary combustion chamber; the middle part is provided with a natural gas burner, which is used to input heat to keep the temperature in the tubular multi-stage incineration tower at 750-850℃, which is convenient for incinerating waste salt; the lower part is provided with an air inlet, which is connected to a blower, which is used to provide combustion air for the natural gas burner and to reduce the temperature of the lower space of the tubular multi-stage incineration tower, which is convenient for cooling waste salt;

[0051] The high-temperature flue gas in the tubular multi-stage incineration tower carries the precipitated organic matter into the secondary combustion chamber. The secondary combustion chamber is equipped with a natural gas burner to further heat the high-temperature flue gas to raise its temperature to above 1100°C, completely decomposing the organic matter. A circulating flue gas inlet is arranged at the lower part of the secondary combustion chamber. The circulating flue gas can provide combustion-supporting air for the combustion of the natural gas burner and reduce the temperature of the lower space of the secondary combustion chamber to facilitate the cooling of the molten waste salt.

[0052] SNCR denitrification is installed at the outlet of the secondary combustion chamber to initially reduce the nitrogen oxide content in the high-temperature flue gas;

[0053] The outlet of the second combustion chamber is connected to the rapid cooler;

[0054] The rapid cooler is a vertical water-tube waste heat boiler. The inlet superheater adopts a wide-pitch steam-water membrane screen to allow low-melting-point crystalline salt to condense slag here, and the flue gas temperature drops below 600°C. The subsequent reheater heating surface is designed with a wide-pitch, high-flow convection serpentine tube; two layers of SCR catalysts are set in the 380°C flue gas temperature area at the economizer inlet. After denitration, NOX is less than 100mg / Nm3, meeting environmental protection requirements; the flue gas temperature after SCR denitration drops to 150°C and enters the dust collector for dust removal;

[0055] The economizer outlet is the rapid cooler outlet, which is connected to the dust collector inlet; the final emission concentration of flue gas particulate matter at the dust collector outlet is 5mg / Nm3, which meets environmental protection requirements;

[0056] The dust collector outlet is connected to the induced draft fan;

[0057] The induced draft fan has two outlets, one connected to the flue gas circulation system and the other connected to the desulfurization system;

[0058] The flue gas circulation system is used to provide combustion air for the natural gas burner in the secondary combustion chamber and to reduce the temperature of the lower space of the secondary combustion chamber to facilitate cooling of the molten waste salt.

[0059] The desulfurization system purifies the flue gas after dust removal. Ammonia desulfurization can be used to remove SO2 in the flue gas. The final emission concentration of SO2 in the flue gas is 35mg / Nm3, which meets environmental protection requirements.

[0060] Flue gas is discharged into the atmosphere through the desulfurization system;

[0061] Through the above process, the decomposition of organic matter precipitated from waste salt and the purification of high-temperature flue gas are completed, and the exhaust gas is discharged after meeting environmental protection requirements;

[0062] 3. Utilization of waste heat from flue gas:

[0063] The water supply temperature of the water supply system is 50℃. The water supply system is connected to the superheater. The water supply system transports desalted water to the superheater, reheater and economizer. The high-temperature flue gas exchanges heat with the desalted water to generate saturated steam, which is sent to users through the steam outlet of the rapid cooler for unified use.

[0064] Because the waste salt is granular, there are particles of different sizes and different weights. They flow countercurrently with the hot air, that is, the waste salt falls from the top of the tower, and the hot air flows from bottom to top. The large particles will fall quickly, and then be lifted to the top of the tower by the elevator again, and then incinerated again. After continuous incineration, the particle size is constantly getting smaller.

[0065] Most of them will reach a state of slow descent under the blowing of hot air (this state is achieved by adjusting the air pressure of the blower), continue to burn, and finally fall to the bottom of the incineration tower after the organic matter on the surface is completely precipitated;

[0066] The particles with small size and small proportion will enter the secondary combustion chamber for high-temperature incineration under the blowing of hot air;

[0067] The liquid is mainly concentrated brine. After entering the incineration area, the water evaporates under high temperature, leaving only the salt. It will enter the secondary combustion chamber along with the high-temperature flue gas for high-temperature incineration to completely precipitate the organic matter.

[0068] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for continuous incineration and recycling of industrial waste salt, characterized in that: It comprises a tubular multi-stage incineration tower (1) and an elevator (2), wherein the upper end of the elevator (2) is connected to a feeder (1-1-1) through an elevator salt outlet (2-2-1), the lower end of the feeder (1-1-1) is connected to the tubular multi-stage incineration tower (1), the bottom of the tubular multi-stage incineration tower (1) is connected to a slag cooler (1-4-1), the lower end of the slag cooler (1-4-1) is connected to a bidirectional conveyor (1-5-1), the side end of the bidirectional conveyor (1-5-1) is connected to a silo (9), the other side of the bidirectional conveyor (1-5-1) is connected to a elevator salt inlet (2-1-1), a concentrated brine injection port (10) is provided at the middle position of the tubular multi-stage incineration tower (1), and a natural gas burner (1-2-1) is provided at a symmetrical position of the concentrated brine injection port (10); The top of the tubular multi-stage incineration tower (1) is connected to a secondary combustion chamber (3), the upper end of the secondary combustion chamber (3) is equipped with a secondary combustion chamber natural gas burner (3-1-1), the lower end of the secondary combustion chamber (3) is provided with a rapid cooler (4), and the water supply system (5) is connected to the rapid cooler (4), the side end of the rapid cooler (4) is connected to an induced draft fan (7) through a dust collector (6), the side end of the induced draft fan (7) is connected to a desulfurization system (8), and the induced draft fan (7) is also connected to a flue gas circulation system (7-1-1), and the flue gas circulation system (7-1-1) is connected to the secondary combustion chamber (3).

2. The device for continuous incineration and recycling of industrial waste salt according to claim 1, characterized in that: The rapid cooler (4) comprises an evaporator (4-1-1), an economizer (4-1-2), a desalted water inlet (4-2-1) and a steam outlet (4-2-2); the upper end of the desalted water inlet (4-2-1) is connected to the steam outlet (4-2-2) through the evaporator (4-1-1), and the economizer (4-1-2) is provided at the bottom of the evaporator (4-1-1).

3. The device for continuous incineration and recycling of industrial waste salt according to claim 2, characterized in that: The silo (9) is connected to the elevator (2) via a bidirectional conveyor (1-5-1), and the elevator (2) is connected to the feeder (1-1-1) via an elevator salt outlet (2-2-1).

4. The device for continuous incineration and recycling of industrial waste salt according to claim 3 is characterized in that: The bidirectional conveyor (1-5-1) is capable of bidirectional transmission.

5. The device for continuous incineration and recycling of industrial waste salt according to claim 4, characterized in that: The tubular multi-stage incineration tower (1) is a circumferential body and is heated by natural gas.

6. The device for continuous incineration and recycling of industrial waste salt according to claim 5, characterized in that: The rapid cooler (4) is a vertical water tube waste heat boiler, and the inlet section adopts a wide-pitch steam-water film screen.

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