Microwave high-temperature melting device for waste salt treatment

Abstract

The utility model discloses a microwave high-temperature melting device for waste salt treatment. The device mainly comprises the following components: a feeding device (1), a groove type microwave high-temperature melting furnace (2), a molten salt cooling device (3), a crushing device (4), a discharge sealing device (5) and a smoke outlet (6) with a check valve, a furnace body bracket (7); the high-temperature melting treatment of the waste salt is realized by microwave heating, and organic matters in the waste salt can be quickly and efficiently pyrolyzed; the adaptability of the device is strong, and various organic matter-containing waste salts can be widely pyrolyzed and treated; the refractory material in the device and the stirring device adopt high-temperature-resistant and corrosion-resistant design, so that the long-term use performance of the device in a high-temperature environment can be effectively ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of high-temperature treatment of waste salt, in particular to a microwave high-temperature melting device for treating waste salt. Background Art

[0002] Waste salt is a common hazardous waste produced by the chemical, pharmaceutical, pesticide and other industries, with the characteristics of large output, multiple types, complex composition, and great environmental hazards. At present, the annual output of various types of waste salt in my country has exceeded 20 million tons. Due to the limited output of the waste salt treatment industry, the waste salt produced by many enterprises can only be temporarily stored in warehouses within the factory, which not only occupies a large amount of factory space and affects the production of enterprises, but also poses the risk of secondary pollution. Summary of the invention

[0003] The main pollutants in waste salt are mostly refractory organic matter. Effective terminal treatment methods include incineration and pyrolysis. Through high-temperature treatment, the organic matter in waste salt is decomposed into inorganic small molecule gas and pyrolytic carbon, eliminating the harmfulness of waste salt. Regenerated salt can be obtained through further dissolution and recrystallization. However, the existing treatment methods also have certain shortcomings. The incineration method has a high treatment temperature, which is difficult to control, and is prone to problems such as equipment adhesion, salt agglomeration, and incomplete removal of organic matter. The indirect heating method used in conventional pyrolysis treatment has low heating efficiency and high treatment energy consumption.

[0004] The search found that the existing microwave pyrolysis device, a waste salt pyrolysis online crushing device (publication number CN219357367U), uses microwave heating and two-stage pyrolysis to treat waste salt. The first stage is a low-temperature treatment that uses a roller with spiral ribs on the surface to push the material forward, and the second stage uses a chain conveyor to transport the material and crush the material. Since the secondary pyrolysis process uses chain conveyors, its operating temperature cannot be too high (less than 600°C), otherwise the conveying mechanism, rotating parts, etc. are easily deformed and damaged, and cannot work stably for a long time. The pyrolysis temperature of some aldehydes and ketones is as high as 700-800°C. When the treatment temperature is low, the problem of incomplete pyrolysis and removal of organic matter will occur.

[0005] Problems with existing waste salt pyrolysis treatment equipment:

[0006] 1. Conventional heating pyrolysis equipment has low heating efficiency and high processing energy consumption;

[0007] 2. The microwave pyrolysis equipment has low processing temperature, slow processing speed, and poor equipment adaptability.

[0008] In order to solve the problems of low heating efficiency and poor adaptability of current waste salt pyrolysis equipment, the utility model provides a microwave high-temperature melting device for waste salt treatment, which uses microwave heating instead of traditional heating, improves the energy utilization rate in the waste salt pyrolysis treatment process, reduces the treatment energy consumption, and makes special designs on the equipment structure and refractory materials so that the equipment has a higher heat resistance limit and long-term stable performance. The operating temperature of the equipment can reach above the melting point of the waste salt, the pyrolysis temperature is higher, the treatment speed is faster, and the equipment has stronger adaptability.

[0009] To achieve the above-mentioned purpose, the utility model provides a waste salt treatment microwave high-temperature melting device, characterized in that it comprises the following components: a feeding device (1), a trough-type microwave high-temperature melting furnace (2), a molten salt cooling device (3), a crushing device (4), a discharge sealing device (5), a smoke exhaust port with a check valve (6); a furnace body support (7);

[0010] The feeding device (1) and the smoke exhaust port (6) with a check valve are arranged at the feeding end of the trough-type microwave high-temperature melting furnace (2);

[0011] The molten salt cooling device (3), the crushing device (4) and the discharge sealing device (5) are connected in sequence and arranged at the discharge end of the trough-type microwave high-temperature melting furnace (2); the other end of the molten salt cooling device (3) is connected to the discharge port of the trough-type microwave high-temperature melting furnace (2); the horizontal height of the feed end is higher than the horizontal height of the discharge end;

[0012] The trough-shaped microwave high-temperature melting furnace (2) is composed of a trough-shaped furnace chamber (2-1) whose inner surface is made of semicircular arc-shaped refractory material, a stirring device (2-2) passing through the furnace chamber, a microwave source (2-3) installed on the top and side of the furnace body, a metal shell (2-4), and a temperature measurement module (2-5);

[0013] The waste salt enters the trough-shaped furnace chamber (2-1) of the trough-shaped microwave high-temperature melting furnace (2) through the feeding device (1), and the waste salt is heated by microwaves in the trough-shaped furnace chamber to a semi-molten state or a molten state, and then is pushed out to the discharge end of the trough-shaped microwave high-temperature melting furnace by the stirring device (2-2). The high-temperature waste salt is cooled and crushed by the molten salt cooling device (3) and the crushing device (4) to become powdered salt with organic matter completely removed, and is finally discharged out of the furnace through the discharge sealing device (5).

[0014] Furthermore, the feeding device (1) comprises a feeding hopper (1-1) and a screw feeder (1-2); the lower end of the feeding hopper (1-1) is connected to the screw feeder (1-2), and the other end of the screw feeder (1-2) is connected to the trough-shaped microwave high-temperature melting furnace (2); and a material vibrator (1-3) is arranged on the feeding hopper (1-1).

[0015] Furthermore, the stirring shaft of the stirring device (2-2) is a hollow structure, through which cooling water flows; a plurality of stirring blades are installed on the stirring shaft of the stirring device (2-2), and when the stirring blades move, the materials can be turned over, thereby avoiding adhesion and moving the materials toward the discharge end; optionally, the stirring blades can also be made of ceramic material.

[0016] Furthermore, the refractory material of the arc furnace bottom and the two vertical side surfaces of the trough-shaped furnace chamber (2-1) is made of silicon carbide or silicon nitride, and has the characteristics of high temperature resistance, corrosion resistance and high thermal shock resistance; the top of the trough-shaped furnace chamber (2-1) is provided with a cover plate, which is made of ordinary ceramic material and has microwave transmission characteristics; during normal operation, the arc furnace bottom and the two side surfaces are in contact with high-temperature waste salt, and the top cover plate is not in contact with high-temperature waste salt; the space between the trough-shaped furnace chamber (2-1) and the metal shell (2-4) is filled with a heat-insulating material;

[0017] Preferably, the arc-shaped furnace bottom and the vertical side surfaces on both sides are made of silicon carbide material, and the entire furnace chamber is composed of several pieces of silicon carbide material. Each silicon carbide material partially overlaps to form a complete furnace bottom with good sealing performance; the cover plate on the top of the furnace chamber is made of corundum mullite material, and microwaves can smoothly pass through the cover plate to heat the material in the furnace chamber; since silicon carbide material has certain microwave absorption characteristics, the microwave source on the side of the furnace body can heat the silicon carbide material, so that the furnace chamber temperature remains relatively stable, reducing temperature fluctuations caused by changes in the amount of material in the furnace.

[0018] Furthermore, the molten salt cooling device (3) is a hollow cylindrical structure with cooling water flowing inside, and a scraper (3-1) is provided on the side of the cylinder to scrape off solids adhering to the cylinder.

[0019] Furthermore, the discharge sealing device is an air shutoff or a star-shaped discharger or a rotary feed valve;

[0020] The screw feeder at the feed end, the sealing device at the discharge end and the exhaust port with a check valve together achieve a sealing effect in the furnace, which can maintain an oxygen-free or oxygen-deficient environment in the furnace during the pyrolysis of waste salt, reduce pyrolysis gas emissions, and reduce the dioxin content in the pyrolysis gas.

[0021] Furthermore, the screw feeder (1-2) and the stirring device (2-2) are respectively controlled by respective motors, and different rotation speeds can be adjusted to control the feeding speed and the residence time of the material in the furnace.

[0022] Compared with the existing equipment, the beneficial effects of the utility model are:

[0023] The special high-temperature resistant design improves the adaptability of the equipment. In the process of microwave heating treatment of waste salt containing organic matter, due to the high speed of microwave heating, the crucible or refractory material of ordinary ceramic materials is easily broken due to local high temperature. The refractory furnace is made of high heat-resistant shock-resistant materials such as silicon carbide, and the stirring device in the furnace is designed to be resistant to high temperature. It can achieve long-term stable performance of the equipment under the high temperature of melting of waste salt. At a temperature higher than the melting point of waste salt, almost all organic matter can be effectively pyrolyzed and removed, and the adaptability of the equipment is stronger.

[0024] High-temperature pyrolysis is achieved by microwave heating to increase the heating temperature, shorten the processing time, and improve the pyrolysis efficiency. Compared with existing conventional heating pyrolysis equipment, the direct heating characteristics of microwaves can greatly reduce the energy loss of the pyrolysis process and improve the utilization rate of thermal energy. Compared with existing medium and low temperature microwave pyrolysis, high-temperature pyrolysis can greatly shorten the pyrolysis processing time, improve the processing efficiency of the pyrolysis process, and reduce the energy consumption of pyrolysis processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure and connection of the microwave high-temperature melting device.

[0026] Figure 2 It is a structural schematic diagram of the furnace cross section of the microwave high-temperature melting device.

[0027] Figure 3 Schematic diagram of the structure of the molten salt cooling device.

[0028] In the figure: 1: feeding device, 2: trough-type microwave high-temperature melting furnace, 3: molten salt cooling device, 4: crushing device, 5: discharge sealing device; 6: smoke exhaust port with check valve; 7: furnace body support; 1-1: feeding hopper; 1-2: screw feeder; 1-3: material vibrator; 2-1: trough-type furnace; 2-2: stirring device; 2-3: microwave source; 2-4: metal shell; 2-5: temperature measurement module; 3-1: scraper. DETAILED DESCRIPTION

[0029] The purpose of the utility model device is more clearly explained below in conjunction with specific application examples. Example

[0030] A waste salt treatment microwave high-temperature melting device, characterized in that it comprises the following components: a feeding device (1), a trough-type microwave high-temperature melting furnace (2), a molten salt cooling device (3), a crushing device (4), a discharge sealing device (5), a smoke exhaust port with a check valve (6); and a furnace body support (7);

[0031] The feeding device (1) and the smoke exhaust port (6) with a check valve are arranged at the feeding end of the trough-type microwave high-temperature melting furnace (2);

[0032] The molten salt cooling device (3), the crushing device (4) and the discharge sealing device (5) are connected in sequence and arranged at the discharge end of the trough-type microwave high-temperature melting furnace (2); the other end of the molten salt cooling device (3) is connected to the discharge port of the trough-type microwave high-temperature melting furnace (2); the horizontal height of the feed end is higher than the horizontal height of the discharge end; the feed port and the smoke exhaust port are arranged at the same end, and the high-temperature pyrolysis gas can be used to preheat the low-temperature material newly entering the furnace, thereby improving the heat utilization rate; moreover, some easily condensable components in the smoke, such as macromolecular organic matter or volatile molten salt, will condense on the low-temperature salt and repeatedly return to the high-temperature zone for pyrolysis, which can reduce the amount of discharged pyrolysis gas and reduce the difficulty of pyrolysis gas treatment;

[0033] The trough-shaped microwave high-temperature melting furnace (2) is composed of a trough-shaped furnace chamber (2-1) whose inner surface is made of semicircular arc-shaped refractory material, a stirring device (2-2) passing through the furnace chamber, a microwave source (2-3) installed on the top and side of the furnace body, a metal shell (2-4), and a temperature measurement module (2-5);

[0034] The waste salt enters the trough-shaped furnace chamber (2-1) of the trough-shaped microwave high-temperature melting furnace (2) through the feeding device (1). The waste salt is heated by microwaves into a semi-molten state in the trough-shaped furnace chamber. Under the action of gravity and the push of the stirring device (2-2), the waste salt gradually moves to the discharge end of the trough-shaped microwave high-temperature melting furnace. The high-temperature waste salt falls from the discharge port onto the molten salt cooling device (3) and is cooled into a solid. The waste salt is then broken into powdery salt with organic matter completely removed by the breaking device (4). The waste salt is finally discharged through the discharge sealing device (5) and can be directly discharged into a ton bag container.

[0035] Furthermore, the feeding device (1) comprises a feeding hopper (1-1) and a screw feeder (1-2); the lower end of the feeding hopper (1-1) is connected to the screw feeder (1-2), and the other end of the screw feeder (1-2) is connected to the trough-shaped microwave high-temperature melting furnace (2); and a material vibrator (1-3) is arranged on the feeding hopper (1-1).

[0036] Furthermore, the stirring shaft of the stirring device (2-2) is made of high-temperature resistant stainless steel and has a hollow structure with cooling water passing through it, thereby ensuring the long-term performance of the stirring shaft in a high-temperature environment; a plurality of stirring blades are installed on the stirring shaft of the stirring device (2-2), and when the stirring blades move, the material can be turned over to avoid sticking and move the material toward the discharge end; each group of stirring blades is arranged at 180 degrees, and when one blade in a group is in contact with the high-temperature salt, the other blade is in the atmosphere and is not in contact with the high-temperature salt. The blades are alternately in contact with the high-temperature salt to avoid annealing deformation caused by long-term high temperature.

[0037] Furthermore, the refractory materials of the arc furnace bottom and the vertical side surfaces on both sides of the trough-shaped furnace chamber (2-1) are made of silicon carbide, which has the characteristics of high temperature resistance, corrosion resistance and high thermal shock resistance. The entire furnace chamber is composed of a plurality of silicon carbide materials, and each silicon carbide material partially overlaps to form a complete furnace bottom with good sealing performance. The cover plate on the top of the trough-shaped furnace chamber (2-1) is made of corundum mullite, and microwaves can smoothly pass through the cover plate to heat the material in the furnace chamber, thereby reducing losses. During normal operation, the arc furnace bottom and the two side surfaces are in contact with high-temperature waste salt, and the top cover plate is not in contact with high-temperature waste salt. Since silicon carbide material has certain microwave absorption characteristics, the microwave source on the side of the furnace body can heat the silicon carbide material, so that the furnace temperature remains relatively stable, reducing temperature fluctuations caused by different amounts of materials in the furnace. The trough-shaped furnace chamber (2-1) and the metal shell (2-4) are filled with insulation material to reduce the loss of temperature in the furnace.

[0038] Furthermore, the molten salt cooling device (3) is made of heat-resistant stainless steel and is designed as a hollow cylindrical structure with cooling water flowing inside. After the high-temperature molten salt falls onto the cooling device, it is cooled into a solid. A scraper (3-1) is provided on the side of the cylinder to scrape off the solid adhering to the cylinder.

[0039] Furthermore, the discharge sealing device is a star-shaped discharger; the screw feeder at the feed end, the sealing device at the discharge end and the exhaust port with a check valve jointly achieve a sealing effect in the furnace, which can maintain an oxygen-free or oxygen-deficient environment in the furnace during the pyrolysis of waste salt, reduce the gas emissions during the pyrolysis process, and the oxygen-free environment can also reduce the content of dioxins in the pyrolysis gas.

[0040] Furthermore, the screw feeder (1-2) and the stirring device (2-2) are respectively controlled by respective motors, and different rotation speeds can be adjusted to control the feeding speed and the residence time of the material in the furnace.

Claims

1. A microwave high-temperature melting device for waste salt treatment, characterized in that: The invention comprises the following components: a feeding device (1), a trough-type microwave high-temperature melting furnace (2), a molten salt cooling device (3), a crushing device (4), a discharge sealing device (5), a smoke exhaust port with a check valve (6), and a furnace body support (7); The feeding device (1) and the smoke exhaust port (6) with a check valve are arranged at the feeding end of the trough-type microwave high-temperature melting furnace (2); The molten salt cooling device (3), the crushing device (4) and the discharge sealing device (5) are connected in sequence and arranged at the discharge end of the trough-type microwave high-temperature melting furnace (2); the other end of the molten salt cooling device (3) is connected to the discharge port of the trough-type microwave high-temperature melting furnace (2); the horizontal height of the feed end is higher than the horizontal height of the discharge end; The trough-shaped microwave high-temperature melting furnace (2) is composed of a trough-shaped furnace chamber (2-1) whose inner surface is made of semicircular arc-shaped refractory material, a stirring device (2-2) passing through the furnace chamber, a microwave source (2-3) installed on the top and side of the furnace body, a metal shell (2-4), and a temperature measurement module (2-5); The waste salt enters the trough-shaped furnace chamber (2-1) of the trough-shaped microwave high-temperature melting furnace (2) through the feeding device (1), and the waste salt is heated by microwaves in the trough-shaped furnace chamber into a semi-molten state or a molten state, and then is pushed out to the discharge end of the melting furnace by the stirring device (2-2). The high-temperature waste salt is cooled and crushed by the molten salt cooling device (3) and the crushing device (4) to become powdered salt with organic matter completely removed, and is finally discharged from the furnace through the discharge sealing device (5).

2. A waste salt treatment microwave high temperature melting device according to claim 1, characterized in that: The feeding device (1) comprises a feeding hopper (1-1) and a screw feeder (1-2); the lower end of the feeding hopper (1-1) is connected to the screw feeder (1-2), and the other end of the screw feeder (1-2) is connected to the trough-shaped microwave high-temperature melting furnace (2); and a material vibrator (1-3) is arranged on the feeding hopper (1-1).

3. A waste salt treatment microwave high temperature melting device according to claim 1, characterized in that: The stirring shaft of the stirring device (2-2) is a hollow structure, through which cooling water flows; a plurality of stirring blades are mounted on the stirring shaft of the stirring device (2-2), and when the stirring blades move, the material can be turned over, thereby avoiding adhesion and moving the material toward the discharge end.

4. A waste salt treatment microwave high temperature melting device according to claim 1, characterized in that: The refractory material of the arc furnace bottom and the two vertical side surfaces of the trough-shaped furnace chamber (2-1) is made of silicon carbide or silicon nitride, and has the characteristics of high temperature resistance, corrosion resistance and high thermal shock resistance. The top of the trough-shaped furnace chamber (2-1) is provided with a cover plate, which is made of ordinary ceramic material and has microwave transmission characteristics. During normal operation, the arc furnace bottom and the two side surfaces are in contact with high-temperature waste salt, and the top cover plate is not in contact with high-temperature waste salt. The space between the trough-shaped furnace chamber (2-1) and the metal shell (2-4) is filled with thermal insulation material.

5. The microwave high-temperature melting device for waste salt treatment according to claim 1, characterized in that: The molten salt cooling device (3) is a hollow cylindrical structure with cooling water flowing inside. A scraper (3-1) is provided on the side of the cylinder to scrape off solids adhering to the cylinder.

6. The microwave high-temperature melting device for waste salt treatment according to claim 1, characterized in that: The discharge sealing device is an air shutoff, a star-shaped discharger or a rotary feed valve.

7. A waste salt treatment microwave high temperature melting device according to claim 2, characterized in that: The screw feeder (1-2) and the stirring device (2-2) are respectively controlled by respective motors, and different rotation speeds can be adjusted to control the feeding speed and the residence time of the material in the furnace.

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