Chemical waste salt incineration disposal and resource utilization device and method

Abstract

The present application relates to waste salt incineration and resource utilization field, disclose chemical waste salt incineration disposal and resource utilization device and method, including heat insulation furnace and the waste heat boiler connected with heat insulation furnace;The top of heat insulation furnace is provided with burner;The upper portion of heat insulation furnace is provided with feeding equipment;The bottom of heat insulation furnace is provided with slagging port;The lower portion of heat insulation furnace is provided with flue gas outlet;The waste heat boiler is provided with air preheater, and the air preheater is connected with the burner through hot air main pipe.The present application is provided with burner and through feeding equipment simultaneously spraying waste salt and air, the combustion temperature can be controlled at 1100 DEG C and above by using less auxiliary fuel, the organic matter in waste salt can be completely removed, the problems of clogging molten salt nozzle and unstable feeding can be avoided, further still provided with clean slag burner, the situation that it is difficult to discharge molten salt slag can be effectively solved, and the flue gas can reach the purpose of standard emission through subsequent flue gas purification facilities.

Description

Technical Field

[0001] This invention relates to the field of waste salt incineration and resource utilization, specifically to apparatus and methods for the incineration and resource utilization of chemical waste salt. Background Technology

[0002] As national environmental protection standards become increasingly stringent, the requirements for the total salt content of wastewater discharged by production enterprises are also becoming more stringent. Large quantities of waste salt (mostly alkali metal salts) are generated during the production of intermediates or products in industries such as petrochemicals, coal chemicals, pesticides, printing and dyeing, pharmaceuticals, and fine chemicals. Because these waste salts contain toxic and harmful chemicals, they cannot be used directly as industrial raw materials and are therefore stockpiled. As production progresses, these waste salts gradually fill warehouses and occupy large amounts of outdoor land. The toxic organic substances contained in most of the soluble salts are washed away by rainwater, severely damaging surrounding vegetation and posing a serious impact on the local environment. Therefore, the effective and resource-based treatment of these by-product waste salts has become an urgent problem that the chemical industry needs to solve.

[0003] Currently, physical, chemical, and high-temperature heat treatment methods are commonly used to detoxify waste salt, recover industrial salt that meets standards, and reuse it in industrial production, thus achieving the recycling of industrial salt. Physical methods for removing organic matter from waste salt mainly include salt washing, extraction, and adsorption. Chemical methods involve dissolving waste salt in water and then using advanced oxidation technologies to degrade organic pollutants, achieving the harmlessness of the waste salt. Commonly used organic oxidation technologies include advanced oxidation processes, wet catalytic oxidation, hydrothermal oxidation, and electrochemical oxidation. High-temperature heat treatment refers to methods that remove organic matter from waste salt by heating it to its boiling point or pyrolysis temperature; these mainly include pyrolysis carbonization and high-temperature melting.

[0004] The efficiency of pyrolysis carbonization is greatly affected by heat treatment conditions and equipment, and its removal of organic matter is limited. High-temperature melting, on the other hand, removes organic matter at temperatures above the melting point of waste salt, typically between 800 and 1200°C. At this temperature, the waste salt is in a dissolved state, and the organic matter is completely removed, resulting in high removal efficiency. However, it also presents engineering challenges such as easy clogging of the molten salt nozzle, unstable feeding, and difficulty in precisely controlling the flue gas residence time. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of low waste salt treatment and removal efficiency, easy clogging of molten salt nozzles, unstable feeding, and difficulty in controlling the residence time of high-temperature flue gas in the existing technology. This invention provides a device and method for the incineration and resource utilization of chemical waste salt. By setting up a burner and simultaneously spraying waste salt and air through a feeding device, the combustion temperature can be controlled at 1100℃ and above with less fuel. This can thoroughly remove organic matter from the waste salt and avoid the problems of clogging of molten salt nozzles and unstable feeding. Furthermore, a slag-removing burner is set up to effectively solve the problem of difficulty in discharging molten salt slag. At the same time, the subsequent flue gas purification facilities can achieve the goal of meeting emission standards.

[0006] To achieve the above objectives, the present invention provides a chemical waste salt incineration and resource utilization device, including an insulated furnace and a waste heat furnace connected to the insulated furnace.

[0007] The top of the insulated furnace is equipped with a burner, which is used to burn fuel to produce fuel flue gas and provide heat.

[0008] The upper part of the insulation furnace is equipped with a feeding device, which is used to spray waste salt and air into the insulation furnace. The waste salt and air come into contact with the fuel flue gas in the insulation furnace and are burned to generate waste salt flue gas and inorganic salt alkali ash.

[0009] The bottom of the insulated furnace is provided with a slag discharge port for discharging inorganic salt and alkali ash.

[0010] The lower part of the insulated furnace is provided with a flue gas outlet, through which fuel flue gas and waste salt flue gas are discharged and enter the waste heat furnace.

[0011] An air preheater is installed inside the waste heat furnace. The air preheater is connected to the burner through a hot air main pipe. Fuel flue gas and waste salt flue gas from the insulated furnace pass through the air preheater to heat the air. The heated air is then sent to the burner through the hot air main pipe for combustion.

[0012] Preferably, the feeding device includes a feeding duct and a plurality of feeding nozzles connected to the feeding duct;

[0013] The feeding air duct is an annular air duct and is located on the outer periphery of the insulated furnace;

[0014] The feeding nozzle is located on the outer wall of the insulated furnace and is inserted into the cylinder.

[0015] Preferably, the insulated furnace is further provided with an air supply device, which is connected to the hot air main pipe and is used to spray heated air from the hot air main pipe into the insulated furnace.

[0016] Preferably, the air supply device is located below the feeding device;

[0017] The air supply equipment includes an air supply duct and multiple air supply nozzles connected to the air supply duct.

[0018] The air supply duct is an annular duct and is located on the outer periphery of the insulated furnace;

[0019] The air supply nozzle is located on the outer wall of the insulated furnace and inserted into the cylinder.

[0020] Preferably, a slag-cleaning burner is also provided at the bottom of the insulated furnace. The slag-cleaning burner is located above the slag discharge port and connected to the hot air main pipe. Heated air from the hot air main pipe enters the slag-cleaning burner for combustion to provide heat.

[0021] Preferably, the waste heat furnace is further provided with a steam superheater and an economizer, and the air preheater is located between the steam superheater and the economizer;

[0022] Fuel flue gas and waste salt flue gas from the adiabatic furnace pass through a steam superheater to heat the steam, then through an air preheater to heat the air, and finally through an economizer to heat the boiler feedwater.

[0023] Preferably, a water-cooled wall is provided on the inner wall between the flue gas inlet of the waste heat furnace and the steam superheater.

[0024] Preferably, the chemical waste salt incineration and resource utilization device further includes a steam drum installed above the waste heat furnace, the upper outlet of the water-cooled wall is connected to the inlet of the steam drum through a riser pipe, the water outlet of the steam drum is connected to the lower inlet of the water-cooled wall through a downcomer pipe, and the steam outlet of the steam drum is connected to the steam inlet of the steam superheater through a steam outlet pipe.

[0025] A second aspect of this invention provides a method for the incineration and resource utilization of chemical waste salt, wherein the method is implemented in the aforementioned incineration and resource utilization process of chemical waste salt, and the method includes:

[0026] The burner at the top of the insulated furnace is controlled to burn fuel and produce fuel flue gas, which provides heat;

[0027] Waste salt and air are injected into the insulated furnace using the feeding equipment at the top of the furnace. The waste salt and air come into contact with the fuel flue gas in the furnace and are burned to generate waste salt flue gas and inorganic salt ash. The inorganic salt ash is discharged from the slag discharge port at the bottom of the insulated furnace.

[0028] Fuel flue gas and waste salt flue gas are discharged through the flue gas outlet at the bottom of the insulated furnace and enter the waste heat furnace. Then, they pass through the air preheater in the waste heat furnace to heat the air. The heated air is then sent to the burner through the hot air main pipe for combustion.

[0029] Preferably, the waste salt and air come into contact with the fuel flue gas in the insulated furnace, and the combustion temperature is ≥1100℃.

[0030] The beneficial effects of this invention are:

[0031] This invention relates to a chemical waste salt incineration and resource utilization device. A burner is located at the top of an insulated furnace to provide the high-temperature flue gas required for waste salt combustion. Air and waste salt are injected into the furnace chamber through a feeding device located at the top of the furnace. This device both feeds the waste salt into the furnace and provides the air needed for the combustion of organic matter in the waste salt. A slag discharge port is located at the bottom of the insulated furnace. The combustion of waste salt occurs within the furnace chamber (which has a circular cross-section), significantly reducing heat loss and maintaining a high temperature within the furnace. The combustion temperature within the furnace chamber is controlled by adjusting the amount of auxiliary fuel (fuel gas, fuel oil, etc.). An air preheater is also included, connected to the burner. The air preheater effectively increases the temperature of the combustion air entering the furnace, ensuring complete combustion of organic matter in the waste salt within the furnace, reducing auxiliary fuel consumption, and recovering waste heat from the high-temperature flue gas generated by the furnace. Waste salt treated by this device can achieve an organic matter incineration removal rate of ≥99.99% and a loss on ignition rate of <5%, facilitating resource utilization by users. This invention can be applied to fields such as petrochemicals, coal chemicals, pesticides, printing and dyeing, pharmaceuticals, and fine chemicals to achieve the harmlessness, reduction, and resource utilization of waste salt. It reduces the volume of waste salt before final disposal and transforms harmful substances in waste salt into harmless substances, realizing the recycling of waste salt and turning waste into treasure. At the same time, it recovers the waste heat generated during the incineration process. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the chemical waste salt incineration and resource utilization device of the present invention.

[0033] Explanation of reference numerals in the attached figures

[0034] 1. Insulating furnace; 2. Waste heat furnace; 3. Burner; 4. Feeding equipment; 5. Slag discharge port; 6. Air preheater; 7. Hot air main pipe; 8. Air supply equipment; 9. Slag removal burner; 10. Steam superheater; 11. Economizer; 12. Steam drum; 13. Air duct for burner; 14. Air pipe for slag removal burner. Detailed Implementation

[0035] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0036] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0037] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0038] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions provided in the various embodiments of this invention can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0039] Example 1

[0040] like Figure 1 The chemical waste salt incineration and resource utilization device shown includes an insulated furnace 1 and a waste heat furnace 2 connected to the insulated furnace 1.

[0041] The top of the insulated furnace 1 is equipped with a burner 3, which is used to burn fuel to produce fuel flue gas and provide heat.

[0042] The upper part of the insulation furnace 1 is provided with a feeding device 4, which is used to spray waste salt and air into the insulation furnace 1. The waste salt and air come into contact with the fuel flue gas in the insulation furnace 1 and are burned to generate waste salt flue gas and inorganic salt alkali ash.

[0043] The bottom of the insulated furnace 1 is provided with a slag discharge port 5 for discharging inorganic salt and alkali ash;

[0044] The lower part of the adiabatic furnace 1 is provided with a flue gas outlet, through which fuel flue gas and waste salt flue gas are discharged and enter the waste heat furnace 2.

[0045] An air preheater 6 is installed inside the waste heat furnace 2. The air preheater 6 is connected to the burner 3 through the hot air main pipe 7. The fuel flue gas and waste salt flue gas from the adiabatic furnace 1 pass through the air preheater 6 to heat the air. The heated air is then sent to the burner 3 through the hot air main pipe 7 for combustion.

[0046] In this invention, the outer wall of the insulated furnace 1 is made of steel plate, and the inner wall is provided with a heat insulation material layer and a refractory material layer in sequence. The heat insulation material layer is made of heat insulation material commonly used in the art, and is used for heat preservation. The refractory material layer is made of refractory material commonly used in the art, so as to reduce heat loss.

[0047] In the burner 3 of this invention, auxiliary fuel is burned. The auxiliary fuel can be fuel gas, fuel oil, etc., mainly to generate high-temperature fuel flue gas for combustion, providing heat for the combustion of waste salt. The specific composition and amount of the auxiliary fuel are related to the specific composition of the waste salt. Because different wastes have different calorific values, the amount of auxiliary fuel required is different. Therefore, the amount or composition of the auxiliary fuel can be adjusted. As long as the burner 3 can burn these auxiliary fuels to make the temperature inside the insulated furnace 1 reach the temperature of complete combustion of waste salt (≥1100℃) (for example, the amount of auxiliary fuel can be increased, or auxiliary fuel with a high calorific value can be used to make the temperature inside the insulated furnace 1 ≥1100℃).

[0048] Because this invention uses an insulated furnace 1, which has a good heat preservation effect, compared with existing treatment methods, this invention can achieve the required temperature of ≥1100℃ in the insulated furnace 1 with less auxiliary fuel (for example, when the auxiliary fuel is natural gas, if one ton of waste salt is being processed and the combustion temperature of the waste salt is ≥1100℃, compared with existing treatment methods, the device of this invention can use 200-300 cubic meters less natural gas per hour; and if the waste salt being processed also has calorific value, the auxiliary fuel required by this invention will be less).

[0049] Furthermore, when processing waste salt, since the high-temperature fuel flue gas needs to stay in the insulated furnace 1 for ≥2s, the insulated furnace 1 used in this invention can select a furnace with appropriate height and size according to the specific amount of high-temperature fuel flue gas, so that the high-temperature fuel flue gas stays in the insulated furnace 1 for ≥2s, and the residence time of high-temperature flue gas can be well controlled.

[0050] Since the combustion of auxiliary fuel by burner 3 requires the participation of oxygen, burner 3 of the present invention is connected to air preheater 6 through hot air main pipe 7. In a preferred embodiment, burner 3 of the present invention is also connected to hot air main pipe 7 through burner air duct 13, and exhaust port of air preheater 6 is connected to hot air main pipe 7. Heated air from air preheater 6 is sent to burner 3 through hot air main pipe 7 through exhaust port and burner air duct 13 to participate in combustion. Sending heated air from air preheater 6 to burner 3 to participate in combustion can effectively increase combustion temperature, reduce auxiliary fuel consumption, and improve the stability and completeness of combustion in insulated furnace 1.

[0051] Furthermore, a first damper is provided on the burner air duct 13 to control whether air is supplied to the burner 3 and to adjust the amount of air supplied.

[0052] The burner 3 used in this invention is an oil / gas burner conventionally used in the art.

[0053] Furthermore, the feeding device 4 includes a feeding duct and multiple feeding nozzles connected to the feeding duct; wherein the feeding duct is an annular duct and is located on the outer periphery of the insulation furnace 1; and the multiple feeding nozzles are all located on the outer wall of the insulation furnace 1 and inserted into the cylinder, and the multiple feeding nozzles are evenly spaced along the outer periphery of the insulation furnace.

[0054] In a preferred embodiment of the present invention, the air is first pressurized by a powder feeding fan and then preheated to obtain preheated air. The preheated air is then sent into an air-powder mixer, where it is mixed evenly with solid waste salt (generated during the production of intermediates or products in the fields of petrochemicals, coal chemicals, pesticides, printing and dyeing, pharmaceuticals, and fine chemicals). The mixture is then sent into a feeding duct (a second damper is provided on the pipe connecting the feeding duct and the air-powder mixer to control whether to feed material into the feeding duct). The mixture of preheated air and solid waste salt is then evenly sprayed into the insulation furnace 1 through multiple feeding nozzles (the number of feeding nozzles and the spraying speed are determined according to the specific operating conditions, as long as the solid waste salt can be evenly sprayed into the insulation furnace 1).

[0055] Because of the different compositions of solid waste salt, it may absorb moisture and clump together. Therefore, the air is preheated before being mixed with the solid waste salt to dry it. The solid waste salt and preheated air are then fed into the insulated furnace 1 through the feeding device 4. This serves two purposes: firstly, to dry the solid waste salt and prevent it from clumping and clogging the nozzles, ensuring stable and uniform feeding; and secondly, to provide oxygen for the combustion of the solid waste salt. The preheated air can both dry the solid waste salt and transport it into the insulated furnace 1, preventing it from clumping, while also providing oxygen for the combustion of organic matter in the waste salt within the furnace 1. The amount of preheated air used is sufficient to dry the solid waste salt.

[0056] In specific situations, after the burner 3 burns the auxiliary fuel, it produces high-temperature fuel flue gas. This high-temperature fuel flue gas flows downward, thereby raising the temperature inside the insulated furnace 1 to the point where the organic matter in the waste salt can be fully burned. The preheated air and solid waste salt, after being mixed evenly, are evenly sprayed into the insulated furnace 1 through multiple feeding nozzles. They come into contact with the high-temperature fuel flue gas produced by the burner 3. The high-temperature fuel flue gas provides heat and is also radiated by the high-temperature flame of the burner 3. The solid waste salt is heated, and after reaching a certain temperature, the solid waste salt and air begin to burn (the organic matter in the solid waste salt will begin to burn). After complete combustion, waste salt flue gas (waste salt flue gas is the flue gas produced by the full combustion of organic matter in waste salt) and inorganic salt ash are generated. The high-temperature fuel flue gas does not participate in the waste salt combustion reaction.

[0057] In a specific embodiment, if the amount of preheated air sprayed into the insulated furnace 1 along with multiple feeding nozzles is insufficient to completely burn and decompose the solid waste salt, air will be added again to ensure complete combustion of the solid waste salt. Based on this, the insulated furnace 1 of the present invention is also equipped with an air supply device 8, which is connected to the hot air main pipe 7 and is used to spray heated air from the hot air main pipe 7 into the insulated furnace 1 (spraying heated air is also to effectively increase the combustion temperature and reduce the consumption of auxiliary fuel). During the descent, the unburned solid waste salt comes into contact with the heated air sprayed into the insulated furnace 1 by the air supply device 8. Under the high temperature provided by the high-temperature fuel flue gas, the organic matter in the solid waste salt can be completely burned (if the amount of preheated air sprayed into the insulated furnace 1 along with multiple feeding nozzles is sufficient to completely burn and decompose the solid waste salt, the air supply device 8 is turned off, and at this time, it is not necessary for the air supply device 8 to spray heated air from the hot air main pipe 7 into the insulated furnace 1).

[0058] Furthermore, the air supply device 8 is located below the material feeding device 4.

[0059] In one specific embodiment, the air supply device 8 is located in the middle of the adiabatic furnace 1.

[0060] The air supply device 8 includes an air supply duct and multiple air supply nozzles connected to the air supply duct; the air supply duct is an annular duct and is located on the outer periphery of the insulation furnace 1; the multiple air supply nozzles are all located on the outer wall of the insulation furnace 1 and inserted into the cylinder, and the multiple air supply nozzles are evenly spaced along the outer periphery of the insulation furnace.

[0061] In this invention, the annular air duct is an annular air duct surrounding the furnace body, and the burner air duct 13, the feeding air duct, and the air supply air duct are all welded from carbon steel plates, with a rectangular or circular cross-section. The main function of the feeding air duct is to distribute the material (solid waste salt and preheated air) to each feeding nozzle and to make the material distribution of each feeding nozzle as uniform as possible. The main function of the air supply air duct is to distribute the combustion air supply to each air supply nozzle and to make the air volume distribution of each air supply nozzle as uniform as possible.

[0062] The feeding nozzle and air supply nozzle in this invention are both common nozzles in the art.

[0063] In a preferred embodiment, the air supply duct is connected to the hot air main pipe 7 via the air supply pipe. The heated air from the air preheater 6 passes through the exhaust port, through the hot air main pipe 7, and through the air supply pipe into the air supply duct. Then, it is evenly sprayed into the insulated furnace 1 through multiple air supply nozzles.

[0064] In this invention, the number of air nozzles and the spraying speed are determined according to the specific operating conditions. As long as the heated air can be sprayed evenly into the insulated furnace 1, and the air has a certain rigidity (i.e., the sprayed air can fill the cross-section of the furnace chamber), it is acceptable.

[0065] In a preferred embodiment, the solid waste salt is fully combusted to generate waste salt flue gas and inorganic salt ash (which is in a molten state). The inorganic salt ash falls into the bottom of the insulated furnace 1 and is discharged from the insulated furnace 1 through the slag discharge port 5. Furthermore, the slag discharge port 5 is also connected to a slag removal device. After the inorganic salt ash is discharged from the insulated furnace 1 through the slag discharge port 5, it enters the slag removal device for subsequent processing. Specifically, the slag removal device can be a slag removal machine commonly used in the art.

[0066] In specific implementations, issues may arise such as insufficient inorganic salt ash, low bottom temperature of the insulated furnace 1, and easy air leakage at the slag discharge port 5. This can lead to the inorganic salt ash falling to the bottom of the insulated furnace 1 cooling and coking. Once coked, the inorganic salt ash is difficult to discharge from the slag discharge port 5. Therefore, the coked inorganic salt ash needs to be reheated to a molten state for easier discharge. Based on this, a slag-cleaning burner 9 is also installed at the bottom of the insulated furnace 1. The slag-cleaning burner 9 also provides heat by burning auxiliary fuel. The combustion of auxiliary fuel by the slag-cleaning burner 9 also requires oxygen. The burner 9 is located above the slag discharge port 5 and connected to the hot air main pipe 7. The heated air from the hot air main pipe 7 enters the slag cleaning burner 9 for combustion, providing heat and raising the temperature here (the heated air supplied to the slag cleaning burner 9 is also to effectively raise the combustion temperature, make the combustion more complete, and reduce the consumption of auxiliary fuel). It is used to heat the coked inorganic salt ash, making it molten and easy to discharge (if the inorganic salt ash is still molten when it falls to the bottom of the insulated furnace 1 and can be directly discharged from the slag discharge port 5, then it is not necessary to turn on the slag cleaning burner 9 for combustion).

[0067] The slag-cleaning burner 9 in this invention is an oil / gas burner conventionally used in the art.

[0068] Furthermore, the ash-cleaning burner 9 is connected to the hot air main pipe 7 via the ash-cleaning burner air duct 14. The heated air from the air preheater 6 passes through the exhaust port, the hot air main pipe 7, and the ash-cleaning burner air duct 14 into the ash-cleaning burner 9 for combustion.

[0069] In a preferred embodiment, a branch pipe is also connected to the hot air main duct 7. The air supply duct is connected to the branch pipe through the air supply pipe, and the ash-cleaning burner 9 is connected to the branch pipe through the ash-cleaning burner air duct 14. The heated air in the hot air main duct 7 is delivered to the air supply duct and the ash-cleaning burner air duct 14 through the branch pipe. A third damper is provided on the air supply duct to control whether air is supplied to the air supply duct. A fourth damper is provided on the ash-cleaning burner air duct 14 to control whether air is supplied to the ash-cleaning burner 9 (similarly, both the third and fourth dampers can adjust the air supply volume).

[0070] The insulating furnace 1 and the waste heat furnace 2 in this invention can be vertical insulating furnaces and vertical waste heat furnaces commonly used in the art, or they can be... Figure 1 The images show supported insulated furnaces and suspended waste heat furnaces, which are common in this field.

[0071] In a specific embodiment of the present invention, the flue gas outlet of the adiabatic furnace 1 is connected to the flue gas inlet of the waste heat furnace 2, and an expansion joint is provided at the connection. A water-cooled wall is provided on the inner wall between the flue gas inlet of the waste heat furnace 2 and the steam superheater 10. Since the flue gas outlet of the adiabatic furnace 1 is made of steel plate, which expands upward, and the flue gas inlet of the waste heat furnace 2 has a water-cooled wall tube, which expands downward, an expansion joint is provided to absorb the expansion at the connection.

[0072] In specific cases, the high-temperature fuel flue gas generated by the combustion of burner 3 and the waste salt flue gas generated by the combustion of waste salt both flow downwards and enter the waste heat furnace 2 through the flue gas outlet of the insulated furnace 1 and the flue gas inlet of the waste heat furnace 2 in sequence (the flue gas generated by the combustion of slag removal burner 9 will also enter the waste heat furnace 2 through the flue gas outlet of the insulated furnace 1 and the flue gas inlet of the waste heat furnace 2 in sequence to participate in the subsequent heat exchange process).

[0073] Furthermore, the waste heat furnace 2 is also equipped with a steam superheater 10 and an economizer 11, and an air preheater 6 is located between the steam superheater 10 and the economizer 11; the high-temperature fuel flue gas and waste salt flue gas from the adiabatic furnace 1 pass through the water-cooled wall and then pass through the steam superheater 10, the air preheater 6 and the economizer 11 in sequence.

[0074] In this invention, the water-cooled wall used is a membrane water-cooled wall conventionally used in the art, and the outer wall of the waste heat furnace 2 is also provided with a heat insulation material layer.

[0075] In a preferred embodiment, the chemical waste salt incineration and resource utilization device of the present invention further includes a steam drum 12 disposed above the waste heat furnace 2 (the steam drum 12 is located outside the waste heat furnace 2 and is not subject to flue gas scouring). The upper outlet of the water-cooled wall is connected to the inlet of the steam drum 12 via a riser pipe, the water outlet of the steam drum 12 is connected to the lower inlet of the water-cooled wall via a downcomer pipe, and the steam outlet of the steam drum 12 is connected to the steam inlet of the steam superheater 10 via a steam outlet pipe. The water-cooled wall contains boiler feedwater. High-temperature fuel flue gas and waste salt flue gas from the adiabatic furnace 1 exchange heat with the boiler feedwater through the water-cooled wall. The water-cooled wall absorbs the heat from the high-temperature fuel flue gas and waste salt flue gas to heat the boiler feedwater into a steam-water mixture. The steam-water mixture flows from the upper part of the water-cooled wall. The steam flows through the riser pipe from the outlet and enters the steam drum 12 through the inlet. In the steam drum 12, steam and water are separated. The separated steam flows from the steam outlet of the steam drum 12 through the steam outlet pipe and into the steam superheater 10 through the steam inlet. The separated water flows from the water outlet of the steam drum 12 through the downcomer and returns to the water-cooled wall through the lower inlet to participate in heat exchange. After passing through the water-cooled wall, the high-temperature fuel flue gas and waste salt flue gas then pass through the steam superheater 10 to participate in the heat exchange process of the steam superheater 10, heating the steam in the steam superheater 10. The steam absorbs the heat from these flue gases and is further heated. The further heated steam can be sent to the steam turbine for cogeneration.

[0076] The steam superheater 10 used in this invention has a screen-type structure, which is beneficial for ash removal.

[0077] In a specific implementation, the air inlet of the air preheater 6 is connected to a blower, which is used to transport air. The air transported by the blower enters the air preheater 6 through the air inlet. The high-temperature fuel flue gas and waste salt flue gas after passing through the steam superheater 10 participate in the heat exchange process of the air preheater 6, heating the air in the air preheater 6 (the air in the air preheater 6 also absorbs the heat of these flue gases, thereby reducing the flue gas temperature and increasing the air temperature, which can be heated to above 250°C). The heated air enters the hot air main pipe 7 through the exhaust port under the action of the blower.

[0078] The air preheater 6 used in this invention has a plate structure, which facilitates dust removal.

[0079] When the auxiliary fuel is first burned in the burner 3, the air required for combustion is also supplied by the blower. The air supplied by the blower enters the air preheater 6 through the air inlet. Then, under the action of the blower, it enters the hot air main pipe 7 through the exhaust port, and then is sent into the burner 3 through the burner air duct 13 to participate in combustion. Since the high temperature fuel flue gas has just been generated at this time, it has not yet had time to heat the air in the air preheater 6. Therefore, the air from the air preheater 6 at this time is room temperature air.

[0080] Furthermore, the high-temperature fuel flue gas and waste salt flue gas after passing through the air preheater 6 then pass through the economizer 11 (which contains boiler feedwater), and participate in the heat exchange process of the economizer 11 to heat the boiler feedwater in the economizer 11 (the boiler feedwater in the economizer 11 also absorbs heat from the flue gas), further recovering heat, improving the thermal efficiency and energy utilization efficiency of the device, and further reducing the temperature of the flue gas to about 170°C.

[0081] The economizer 11 of the present invention adopts a horizontal structure and is arranged in rows, which can reduce the arrangement space and facilitate ash removal.

[0082] In this invention, the flue gas outlet of the waste heat furnace 2 is also connected to a subsequent flue gas treatment facility. The flue gas passing through the economizer 11 enters the flue gas treatment facility through the flue gas outlet of the waste heat furnace 2 for treatment, so that the flue gas meets the standards and is discharged through the chimney. The waste heat furnace 2 is also connected to an induced draft fan. The induced draft fan makes the entire interior of the insulated furnace 1 and the waste heat furnace 2 operate under negative pressure, so that the flue gas can flow from the insulated furnace 1 into the waste heat furnace 2 and pass through the above-mentioned equipment in sequence.

[0083] The chemical waste salt incineration and resource utilization device of the present invention has the following advantages:

[0084] a. An air duct 13 is provided to supply air to the burner 3. The air pressurized by the pulverizing fan is preheated and mixed with solid waste salt in the air-powder mixer. The mixture is then injected into the furnace through evenly arranged feeding nozzles. This not only feeds the waste salt into the furnace but also provides the air needed for the combustion of organic matter in the waste salt. The bottom of the insulated furnace 1 is equipped with a slag discharge port 5 and a slag cleaning burner 9, which can increase the flue gas temperature at the molten salt chute and facilitate the outflow of molten salt. The combustion of waste salt takes place inside the furnace of the insulated furnace 1, which can greatly reduce heat loss and maintain a high temperature inside the furnace. The combustion temperature inside the furnace is controlled by adjusting the amount of auxiliary fuel (fuel gas, fuel oil, etc. provided by the user). At the same time, an air preheater 6 is provided. The air preheater 6 is connected to the air duct 13 for the burner. The air preheater 6 can effectively increase the temperature of the combustion air entering the furnace, ensuring complete combustion of organic matter in the waste salt inside the insulated furnace 1 and reducing the consumption of auxiliary fuel in the insulated furnace 1.

[0085] b. Arranging economizer 11 after air preheater 6 can effectively reduce the exhaust gas density of waste heat boiler, reduce heat loss from exhaust gas, and improve the thermal efficiency of incineration unit.

[0086] c. The arrangement of the steam superheater 10 effectively increases the steam temperature, and the superheated steam is introduced into the steam turbine for combined heat and power generation, further improving energy utilization efficiency.

[0087] d. Staged air supply conforms to the basic principles of combustion, which is conducive to the stability of the air supply system and facilitates adjustment;

[0088] e. The air supply equipment 8 is located below the waste salt feeding equipment 4. It can provide sufficient oxygen for the combustion of organic matter in the waste salt, control the combustion center in the upper part of the furnace, improve the stability of combustion, and further reduce the consumption of auxiliary fuel.

[0089] f. The burner air duct 13 ensures the stability of the main fuel burner at the top of the furnace. Air and waste salt are injected into the furnace together for the combustion of organic matter in the waste salt, so that the flue gas is evenly distributed in the furnace and the consistency of the temperature field is improved. The air supply equipment 8 supplies air for further combustion of combustible organic matter. The air supply nozzles are circumferentially distributed, which can fully mix the air with the high temperature flue gas and ensure that the combustibles remaining in the secondary air area are completely burned.

[0090] g. A good combustion aerodynamic field inside the furnace can effectively reduce the carbon content in the molten ash flowing out from the bottom of the furnace, reduce fly ash carryover, and increase the continuous operation time of the equipment.

[0091] Example 2

[0092] A method for the incineration and resource utilization of chemical waste salt, implemented in the chemical waste salt incineration and resource utilization transfer in Example 1, includes the following steps:

[0093] S1. Turn on the burner 3 at the top of the insulated furnace 1 and turn on the blower connected to the air inlet of the air preheater 6. The air delivered by the blower enters the air preheater 6 through the air inlet. Then, under the action of the blower, it enters the hot air main pipe 7 through the exhaust port of the air preheater 6. Then, open the first damper. The air in the hot air main pipe 7 enters the burner 3 through the burner air duct 13 (and the air supply volume is adjusted by adjusting the first damper). The auxiliary fuel is burned to produce high-temperature fuel flue gas. The high-temperature fuel flue gas flows downward in the insulated furnace 1 (the appropriate height and size of the furnace are selected according to the specific amount of high-temperature fuel flue gas so that the high-temperature fuel flue gas stays in the insulated furnace 1 for ≥2s). The high-temperature fuel flue gas provides heat, causing the temperature inside the insulated furnace 1 to rise.

[0094] S2. After pressurizing the air by the powder feeding fan, it is preheated to obtain preheated air. This preheated air is then sent to the air-powder mixer, where it is mixed evenly with the solid waste salt. Once the temperature inside the insulation furnace 1 reaches ≥1100℃ (by controlling the amount or composition of auxiliary fuel to ensure the temperature inside the insulation furnace 1 reaches ≥1100℃ after combustion), the second damper on the pipe connecting the feeding duct and the air-powder mixer is opened. The evenly mixed preheated air (the amount of preheated air should be sufficient to dry the solid waste salt) and solid waste salt are then sent back into the feeding duct, and then through multiple... Each feeding nozzle evenly sprays preheated air and solid waste salt into the insulated furnace 1. The preheated air and solid waste salt come into contact with the high-temperature fuel flue gas generated by the burner 3 inside the insulated furnace 1. The high-temperature fuel flue gas provides heat, and at the same time, the preheated air and solid waste salt are also radiated by the high-temperature flame of the burner 3. The solid waste salt is heated, and after reaching a certain temperature, the solid waste salt and air begin to burn. The combustion temperature is ≥1100℃. After complete combustion, waste salt flue gas and inorganic salt ash are generated. The inorganic salt ash falls to the bottom of the insulated furnace 1 and is discharged from the insulated furnace 1 through the slag discharge port 5 and enters the slag discharge equipment for subsequent processing.

[0095] The high-temperature fuel flue gas generated by the combustion of S3 and burner 3, as well as the waste salt flue gas generated by the combustion of waste salt, both flow downwards within the adiabatic furnace 1. They sequentially enter the waste heat furnace 2 through the flue gas outlet at the bottom of the adiabatic furnace 1 and the flue gas inlet of the waste heat furnace 2. After passing through the water-cooled wall, they exchange heat with the boiler feedwater. The water-cooled wall absorbs the heat from the high-temperature fuel flue gas and waste salt flue gas, heating the boiler feedwater into a steam-water mixture. The steam-water mixture flows from the upper outlet of the water-cooled wall through the riser pipe and enters the steam drum 12 through the inlet of the steam drum 12. Steam-water separation occurs in drum 12. The separated steam exits from the steam outlet of drum 12, passes through the steam outlet pipe, and enters the steam superheater 10 through the steam inlet. The separated water flows from the water outlet of drum 12 through the downcomer and returns to the water-cooled wall through the lower inlet to participate in heat exchange. High-temperature fuel flue gas and waste salt flue gas pass through the water-cooled wall and then through the steam superheater 10, participating in the heat exchange process of the steam superheater 10 to heat the steam in the steam superheater 10. After absorbing heat from the flue gas, the steam is further heated, and the further heated steam can be sent to the steam turbine for combined heat and power (CHP). The high-temperature fuel flue gas and waste salt flue gas after passing through the steam superheater 10 pass through the air preheater 6, participating in the heat exchange process of the air preheater 6, heating the air in the air preheater 6 to over 250°C. The heated air, under the action of a blower, enters the hot air main duct 7 through the exhaust port of the air preheater 6, and then... The flue gas is fed into the burner 3 through the air duct 13 to participate in combustion; then, the high-temperature fuel flue gas and waste salt flue gas after passing through the air preheater 6 pass through the economizer 11 (which contains boiler feedwater) and participate in the heat exchange process of the economizer 11 to heat the boiler feedwater in the economizer 11, thereby reducing the temperature of these flue gases to about 170°C. The flue gas after passing through the economizer 11 enters the flue gas treatment facility through the flue gas outlet of the waste heat furnace 2 for treatment, so that the flue gas meets the standards and is discharged through the chimney.

[0096] In the above operation, the induced draft fan connected to the waste heat furnace 2 is used to make the entire insulated furnace 1 and waste heat furnace 2 operate under negative pressure, so that the flue gas can flow from the insulated furnace 1 into the waste heat furnace 2 and pass through the above equipment in sequence.

[0097] In step S2, if the amount of preheated air injected into the insulated furnace 1 along with the multiple feeding nozzles is insufficient to completely burn and decompose the solid waste salt, the third air damper is opened (the air supply volume is adjusted by regulating the third air damper). The heated air from the air preheater 6 passes through the exhaust port, the hot air main pipe 7, the branch pipe, and the air supply duct into the air supply channel. Then, it is evenly injected into the insulated furnace 1 through multiple air supply nozzles. During its descent, the incompletely burned solid waste salt comes into contact with the heated air injected into the insulated furnace 1 by the multiple air supply nozzles. Under the high temperature provided by the high-temperature fuel flue gas, the solid waste salt can be completely burned. (If the amount of preheated air injected into the insulated furnace 1 along with the multiple feeding nozzles is sufficient to completely burn and decompose the solid waste salt, the third air damper is closed, and the air supply equipment 8 does not need to inject air from the hot air main pipe 7 into the insulated furnace 1.) (Heated air); however, if the inorganic salt ash that falls to the bottom of the insulated furnace 1 cools and cokes, making it difficult to be discharged from the slag discharge port 5, then the slag cleaning burner 9 is turned on and the fourth air damper is opened (the air supply volume is adjusted by adjusting the fourth air damper). The heated air from the air preheater 6 passes through the exhaust port, through the hot air main pipe 7, through the branch pipe, and through the air duct 14 of the slag cleaning burner into the slag cleaning burner 9. The slag cleaning burner 9 burns to provide heat, raising the temperature here and heating the coked inorganic salt ash, making it molten and easy to discharge. The flue gas generated by the combustion of the slag cleaning burner 9 will also pass through the flue gas outlet of the insulated furnace 1 and the flue gas inlet of the waste heat furnace 2 to enter the waste heat furnace 2 to participate in the subsequent heat exchange process (if the inorganic salt ash is still molten when it falls to the bottom of the insulated furnace 1 and can be directly discharged from the slag discharge port 5, then it is not necessary to turn on the fourth air damper and the slag cleaning burner 9).

[0098] This invention can effectively improve the combustion stability of waste salt, increase energy utilization efficiency by 10%, extend the continuous operation cycle by more than 100%, and reduce auxiliary fuel consumption by more than 30%.

[0099] It should be understood that any parts not described in detail in this specification belong to the prior art.

[0100] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A device for the incineration and resource utilization of chemical waste salt, characterized in that, It includes an insulated furnace (1) and a waste heat furnace (2) connected to the insulated furnace (1); The top of the insulated furnace (1) is provided with a burner (3), which is used to burn fuel to produce fuel flue gas and provide heat; The upper part of the insulated furnace (1) is provided with a feeding device (4), which is used to spray waste salt and air into the insulated furnace (1). The waste salt and air come into contact with the fuel flue gas in the insulated furnace (1) and are burned to generate waste salt flue gas and inorganic salt alkali ash. The bottom of the insulated furnace (1) is provided with a slag discharge port (5) for discharging inorganic salt ash; The lower part of the insulated furnace (1) is provided with a flue gas outlet, through which fuel flue gas and waste salt flue gas are discharged and enter the waste heat furnace (2). An air preheater (6) is installed inside the waste heat furnace (2). The air preheater (6) is connected to the burner (3) through a hot air main pipe (7). The fuel flue gas and waste salt flue gas from the adiabatic furnace (1) pass through the air preheater (6) to heat the air. The heated air is then sent into the burner (3) through the hot air main pipe (7) for combustion. The feeding device (4) includes a feeding duct and multiple feeding nozzles connected to the feeding duct; The feeding air duct is an annular air duct and is located on the outer periphery of the insulated furnace (1); The feeding nozzle is located on the outer wall of the insulated furnace (1) and inserted into the cylinder; The insulated furnace (1) is also equipped with an air supply device (8), which is connected to the hot air main pipe (7) and is used to spray heated air from the hot air main pipe (7) into the insulated furnace (1); The air supply device (8) is located below the feeding device (4); The air supply device (8) includes an air supply duct and a plurality of air supply nozzles connected to the air supply duct; The air supply duct is an annular duct and is located on the outer periphery of the insulated furnace (1); The air supply nozzle is located on the outer wall of the insulated furnace (1) and inserted into the cylinder.

2. The chemical waste salt incineration and resource utilization device according to claim 1, characterized in that, The bottom of the insulated furnace (1) is also equipped with a slag burner (9). The slag burner (9) is located above the slag discharge port (5) and is connected to the hot air main pipe (7). The heated air from the hot air main pipe (7) enters the slag burner (9) for combustion to provide heat.

3. The chemical waste salt incineration and resource utilization device according to claim 1, characterized in that, The waste heat furnace (2) is also equipped with a steam superheater (10) and an economizer (11), and the air preheater (6) is located between the steam superheater (10) and the economizer (11). The fuel flue gas and waste salt flue gas from the adiabatic furnace (1) pass through the steam superheater (10) to heat the steam, then pass through the air preheater (6) to heat the air, and finally pass through the economizer (11) to heat the boiler feedwater.

4. The chemical waste salt incineration and resource utilization device according to claim 3, characterized in that, The waste heat furnace (2) has a water-cooled wall on the inner wall between the flue gas inlet and the steam superheater (10).

5. The chemical waste salt incineration and resource utilization device according to claim 4, characterized in that, The chemical waste salt incineration and resource utilization device also includes a steam drum (12) installed above the waste heat furnace (2). The upper outlet of the water-cooled wall is connected to the inlet of the steam drum (12) through a riser pipe. The water outlet of the steam drum (12) is connected to the lower inlet of the water-cooled wall through a downcomer pipe. The steam outlet of the steam drum (12) is connected to the steam inlet of the steam superheater (10) through a steam outlet pipe.

6. A method for the incineration and resource utilization of chemical waste salt, characterized in that, The method is implemented in the chemical waste salt incineration and resource utilization transfer process described in any one of claims 1-5, and the method includes: The burner (3) at the top of the insulated furnace (1) burns fuel to produce fuel flue gas, which provides heat; Waste salt and air are sprayed into the insulated furnace (1) using the feeding device (4) at the top of the insulated furnace (1). The waste salt and air come into contact with the fuel flue gas in the insulated furnace (1) and are burned to generate waste salt flue gas and inorganic salt ash. The inorganic salt ash is discharged from the slag discharge port (5) at the bottom of the insulated furnace (1). Fuel flue gas and waste salt flue gas are discharged through the flue gas outlet at the bottom of the insulated furnace (1) and enter the waste heat furnace (2). Then, they pass through the air preheater (6) in the waste heat furnace (2) to heat the air. The heated air is then sent to the burner (3) through the hot air main pipe (7) for combustion.

7. The method for incineration and resource utilization of chemical waste salt according to claim 6, characterized in that, Waste salt and air come into contact with fuel flue gas in an adiabatic furnace (1) and are burned at a temperature ≥1100℃.

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