Molten salt furnace device

Abstract

The utility model discloses a molten salt furnace device which comprises a molten salt furnace mechanism, and the molten salt furnace mechanism comprises a molten salt furnace and a heating mechanism. The molten salt furnace comprises a furnace body and a furnace cover covering the furnace body. The furnace cover is provided with a gas collection port, an observation port and an electrode insertion port; the heating mechanism comprises a heating electrode and an electric control device. The fly ash melting furnace has the advantages that fly ash materials after compatibility are conveyed into the furnace body, the furnace body is filled with fused salt, material particles sink, and dissolution and melting reaction are carried out in the process. Part of inorganic salt in the fly ash can be dissolved in the fused salt to become one part of a fused salt system, the fused salt in the furnace body can be continuously increased, the redundant fused salt can overflow from the fused salt overflow port to be recycled in the subsequent process, and the rest part of the fly ash sinks to the bottom and forms a fused glass body under the action of high temperature. And meanwhile, no secondary harmful flue gas is generated, so that the investment and operation cost of a matched flue gas purification system are further saved.

Description

Technical Field

[0001] The utility model relates to the field of hazardous solid waste treatment, in particular to a molten salt furnace device. Background Art

[0002] Fly ash from the incineration of domestic waste contains a large amount of toxic substances such as heavy metals and dioxins. The harmless and resource-based disposal of fly ash has become a key issue in the industry.

[0003] At present, the main methods of fly ash disposal are: chelation landfill, water washing + cement kiln co-disposal, and high-temperature melting. Among them, high-temperature melting technology uses one or more methods such as plasma heating, electrode heating, resistance heating, and chemical fuel heating to heat the fly ash to 1300-1500℃. The fly ash is molten at this temperature, and dioxins are decomposed by high temperature during the melting process. After cooling, the molten fly ash becomes a high-density (about 2.5t / m 3 ), a hard glass body, which is mainly composed of elements such as Ca, Si, Al, and Fe, and the heavy metals in the fly ash are firmly locked in the lattice. High-temperature melting is the most thorough harmless treatment method for fly ash, with good volume reduction effect (up to more than 70%), stable and reliable treatment effect, simple process flow, and can be directly built with supporting facilities of waste incineration plants. The produced glass body can also be used as a resource.

[0004] At present, the high-temperature melting process of fly ash generally adopts plasma melting technology, which has good heating effect but high energy consumption. In addition, secondary flue gas will be generated during the high-temperature melting process, which contains a large amount of dust particles and volatile heavy metals and chloride salts. Therefore, a flue gas purification system with complex process needs to be configured separately, which further increases the disposal cost of fly ash and leads to high cost of fly ash disposal in plasma melting process. Utility Model Content

[0005] In view of this, it is necessary to provide a molten salt furnace device to solve the technical problems of high-temperature melting of fly ash, which produces secondary flue gas and has high disposal costs during the high-temperature melting process.

[0006] In order to achieve the above-mentioned object, the utility model provides a molten salt furnace device, including a molten salt furnace mechanism, wherein the molten salt furnace mechanism includes a molten salt furnace and a heating mechanism;

[0007] The molten salt furnace comprises a furnace body and a furnace cover covering the furnace body; the furnace cover is provided with a gas collecting port, an observation port and an electrode insertion port; a fly ash feeding port is provided at the upper part of one side of the furnace body, a molten salt overflow port is provided at the lower part of the other side of the furnace body, and a molten slag discharge port is provided at the bottom of the furnace body;

[0008] The heating mechanism comprises a heating electrode and an electric control device. The heating electrode is inserted into the furnace body through an electrode insertion port and extends. The electric control device is electrically connected to the heating electrode.

[0009] In some embodiments, the molten salt furnace device also includes a feeding mechanism, which includes a first conveying cylinder, a first shaftless screw and a first rotating driving member. A first feeding port is opened at one end of the first conveying cylinder, and a first discharge port is opened at the other end of the first conveying cylinder. The first shaftless screw is rotated and arranged in the first conveying cylinder. The first rotating driving member is connected to the first shaftless screw and is used to drive the first shaftless screw to rotate.

[0010] In some embodiments, the feeding mechanism further includes a hopper, wherein the hopper is used to store the formulated materials, and an outlet of the hopper is connected to the first feeding port.

[0011] In some embodiments, the outlet of the hopper is provided with a discharge valve.

[0012] In some embodiments, the first rotating driving member includes a first motor and a first reducer, the output end of the first motor is connected to the input end of the first reducer, and the output end of the first reducer is connected to the first shaftless screw.

[0013] In some embodiments, the molten salt furnace further includes an overflow pipe, which is vertically arranged, wherein the lower end of the overflow pipe is connected to the molten salt overflow port, and the upper end of the overflow pipe is used for allowing the overflow molten salt in the molten salt furnace to flow out.

[0014] In some embodiments, the molten salt furnace device further includes a rapid cooling water quenching mechanism, which is used to quench the molten slag discharged from the molten salt furnace to form glass particles.

[0015] In some embodiments, the rapid cooling water quenching mechanism includes a water quenching pool, a slag scooping machine and a heat exchange tube row. The water quenching pool is arranged below the molten slag discharge port, and the slag scooping machine and the heat exchange tube are integrated in the water quenching pool.

[0016] In some embodiments, a flue gas purification system is connected to the gas collecting port.

[0017] In some embodiments, the flue gas purification system includes a quenching tower, a bag dust collector, an induced draft fan and a chimney, the inlet of the quenching tower is connected to the gas collecting port, the outlet of the quenching tower is connected to the inlet of the bag dust collector, the outlet of the bag dust collector is connected to the inlet of the induced draft fan, and the outlet of the induced draft fan is connected to the inlet of the chimney.

[0018] Compared with the prior art, the beneficial effects of the technical solution proposed by the utility model are as follows: the fly ash material after matching is transported to the fly ash feed port and then enters the furnace body. The furnace body is filled with molten salt of the NaCl-KCl system. Due to the density difference between the molten salt and the material particles, the material particles sink and undergo dissolution and melting reactions in the process. Some inorganic salts in the fly ash will dissolve in the molten salt and become part of the molten salt system. The molten salt in the furnace body will continue to increase, and the excess molten salt will overflow from the molten salt overflow port for subsequent recovery. The rest of the fly ash sinks to the bottom and forms a molten glass body under high temperature. Compared with processes such as plasma melting, this process uses electrode heating as the main heating method, with high electric heat conversion rate and low energy consumption. At the same time, since there is no large amount of secondary harmful flue gas generated, a large amount of investment and operating costs of the auxiliary flue gas purification system are saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of an embodiment of the molten salt furnace device provided by the utility model;

[0020] In the figure: 1-feeding mechanism, 11-first conveying cylinder, 111-first feeding port, 112-first discharging port, 12-first shaftless screw, 13-first rotating driving member, 131-first motor, 132-first reducer, 14-hopper, 141-discharging valve, 2-molten salt furnace mechanism, 21-molten salt furnace, 211-furnace body, 2111-fly ash feeding port, 2112-molten salt overflow port, 2113-molten slag discharge port, 2114-molten zone, 2115-molten salt zone, 2116-cavity zone, 212-furnace cover, 2121-gas collecting port, 2122-observation port, 213-overflow pipe, 22-heating mechanism, 221-heating electrode, 5-quenching water quenching mechanism, 51-water quenching tank. DETAILED DESCRIPTION

[0021] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0022] Please refer to Figure 1 The utility model provides a molten salt furnace device, including a feeding mechanism 1, a molten salt furnace mechanism 2 and a rapid cooling water quenching mechanism 5.

[0023] The feeding mechanism 1 is used to convey the matched materials to the molten salt furnace mechanism 2. The feeding mechanism 1 comprises a first conveying cylinder 11, a first shaftless screw 12 and a first rotating driving member 13. A first feeding port 111 is provided at one end of the first conveying cylinder 11, and a first discharging port 112 is provided at the other end of the first conveying cylinder 11. The first shaftless screw 12 is rotatably arranged in the first conveying cylinder 11. The first rotating driving member 13 is connected to the first shaftless screw 12 and is used to drive the first shaftless screw 12 to rotate. When in use, the matched materials are passed into the first feeding port 111, and the first shaftless screw 12 is driven to rotate by the first rotating driving member 13, so that the matched materials move in the first conveying cylinder 11 and are discharged from the first discharging port 112.

[0024] Preferably, please refer to Figure 1 The feeding mechanism 1 further includes a hopper 14, in which the mixed materials are stored, the outlet of the hopper 14 is connected to the first feed port 111, and a discharge valve 141 is provided at the outlet of the hopper 14. By providing the hopper 14, the mixed materials can be stored conveniently.

[0025] For details, please refer to Figure 1 The first rotating driving member 13 includes a first motor 131 and a first reducer 132 , the output end of the first motor 131 is connected to the input end of the first reducer 132 , and the output end of the first reducer 132 is connected to the first shaftless screw 12 .

[0026] Please refer to Figure 1 The molten salt furnace mechanism 2 includes a molten salt furnace 21 and a heating mechanism 22. The molten salt furnace 21 is filled with molten salt, and the molten salt is used to dissolve the matched fly ash. The heating mechanism 22 is used to heat the molten salt.

[0027] Specifically, the molten salt furnace 21 includes a furnace body 211 and a furnace cover 212 covering the furnace body 211; the furnace cover 212 is provided with a gas collecting port 2121, an observation port 2122 and an electrode insertion port; a fly ash feed port 2111 is provided at the upper part of one side of the furnace body 211, and the fly ash feed port 2111 is connected to the first discharge port 112, a molten salt overflow port 2112 is provided at the lower part of the other side of the furnace body 211, and a molten slag discharge port 2113 is provided at the bottom of the furnace body 211. The heating mechanism 22 includes a heating electrode 221 and an electric control device, the heating electrode 221 is inserted into the furnace body 211 through the electrode insertion port and extends, and the electric control device is electrically connected to the heating electrode 221 to realize power supply to the heating electrode 221 and temperature control. During normal operation of the molten salt furnace 21, the mass ratio of molten salt to fly ash should be ensured to be not less than 5:1, and the fly ash should have sufficient contact reaction conditions in the molten salt. The interior of the furnace body 211 can be divided into a melting zone 2114, a molten salt zone 2115 and a cavity zone 2116 from bottom to top, and the heating electrode 221 must extend to the melting zone 2114. During normal operation, the temperature from the molten salt zone 2115 to the bottom melting zone 2114 should be kept within a range of 800-1300°C by means of temperature control, feed rate control, and discharge rate control.

[0028] When in use, the matched materials are transported to the first feed port 111, and the first shaftless screw 12 is driven to rotate by the first rotating driving member 13, so that the matched materials move in the first conveying cylinder 11, and are discharged from the first discharge port 112 to the fly ash feed port 2111, and then enter the furnace body 211. The furnace body 211 is filled with molten salt of the NaCl-KCl system. Due to the density difference between the molten salt and the material particles, the material particles sink, and dissolve and melt in this process. Part of the inorganic salt in the fly ash will dissolve in the molten salt and become part of the molten salt system. The molten salt in the furnace body 211 will continue to increase, and the excess molten salt will overflow from the molten salt overflow port 2112 for subsequent recovery. The rest of the fly ash sinks to the bottom and forms a molten glass body under the action of high temperature. Compared with processes such as plasma melting, this process uses electrode heating as the main heating method, with high electric heat conversion rate and low energy consumption. At the same time, since there is no large amount of secondary harmful flue gas generated, a large amount of investment and operation costs of the auxiliary flue gas purification system are saved.

[0029] Preferably, the molten salt furnace 21 further comprises an overflow pipe 213, the overflow pipe 213 is vertically arranged, the lower end of the overflow pipe 213 is connected to the molten salt overflow port 2112, and the upper end of the overflow pipe 213 is used to communicate with the molten salt cooling recovery system arranged at the rear end, and is used to allow the overflow molten salt in the molten salt furnace 21 to flow out. The height of the upper end of the overflow pipe 213 is the boundary between the molten salt area 2115 and the cavity area 2116. When the liquid level in the molten salt furnace 21 is higher than the height of the upper end of the overflow pipe 213, the molten salt in the molten salt furnace 21 will overflow from the upper end of the overflow pipe 213, thereby ensuring that the molten salt liquid level in the molten salt furnace 21 is highly stable.

[0030] like Figure 1 The rapid cooling water quenching mechanism 5 is used to quench the molten slag discharged from the molten salt furnace 21 to form glass particles.

[0031] Specifically, the rapid cooling water quenching mechanism 5 includes a water quenching pool 51, a slag scooping machine and a heat exchange tube row. The water quenching pool 51 is arranged below the molten slag discharge port 2113, and the slag scooping machine and the heat exchange tube are integrated in the water quenching pool 51. The molten slag discharged from the molten slag discharge port 2113 of the molten salt furnace 21 directly falls into the water quenching pool 51. The slag scooping machine can scoop out the glass particles sunk to the bottom of the water quenching pool. Cooling water is passed into the heat exchange tube row to cool the water temperature in the water quenching pool 51. By controlling the discharge speed of the slag, when it is cooled in the water quenching pool, glass particles with uniform particle size and hard texture can be formed. Since the slag inevitably carries part of the molten salt into the water quenching pool 51, the salt content of the water in the water quenching pool 51 is increased. Therefore, the water for quenching in the water quenching pool 51 needs to be isolated from the external circulating cooling water. When the salt content of the water for quenching reaches 30% (in terms of total chlorine), it needs to be replaced and pumped into the brine tank of the water purification system by a water pump. The slag scavenging equipment is used to remove the glass particles that sink to the bottom of the water quenching tank, which can be packaged and sold for use as building material aggregates, etc.

[0032] Furthermore, the air collecting port 2121 is connected to a flue gas purification system, which includes a quenching tower, a bag-type dust collector, an induced draft fan and a chimney. The inlet of the quenching tower is connected to the air collecting port 2121, the outlet of the quenching tower is connected to the inlet of the bag-type dust collector, the outlet of the bag-type dust collector is connected to the inlet of the induced draft fan, and the outlet of the induced draft fan is connected to the inlet of the chimney; the quenching tower is used to quickly cool the high-temperature flue gas collected from the molten salt furnace and reduce it to below 200°C, and the flue gas then enters the bag-type dust collector for further purification; the induced draft fan is used to provide flow power to the flue gas and maintain a slightly negative pressure state in the front-end system.

[0033] The beneficial effects of the molten salt furnace device provided by the utility model are as follows:

[0034] (1) Solve the fly ash resource problem. Like the fly ash washing + cement kiln collaborative process, the utility model realizes the complete resource utilization of fly ash from the incineration of domestic waste. However, the process method can be directly built on the existing waste incineration plant without considering the coordination with other projects.

[0035] (2) The problem of secondary flue gas is solved. This process uses molten salt high-temperature melting method to treat fly ash. During the process, no large amount of harmful secondary flue gas will be generated, and there is no risk of secondary pollution.

[0036] (3) Cost saving: Compared with plasma melting and other processes, this process uses electrode heating as the main heating method, with high electric heat conversion rate and low energy consumption. At the same time, since there is no large amount of secondary harmful flue gas generated, a large amount of investment and operation cost of the auxiliary flue gas purification system is saved.

[0037] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention.

Claims

1. A molten salt furnace device, characterized in that: It includes a molten salt furnace mechanism, wherein the molten salt furnace mechanism includes a molten salt furnace and a heating mechanism; The molten salt furnace comprises a furnace body and a furnace cover covering the furnace body; the furnace cover is provided with a gas collecting port, an observation port and an electrode insertion port; a fly ash feeding port is provided at the upper part of one side of the furnace body, a molten salt overflow port is provided at the lower part of the other side of the furnace body, and a molten slag discharge port is provided at the bottom of the furnace body; The heating mechanism comprises a heating electrode and an electric control device, the heating electrode is inserted into the furnace body through the electrode insertion port and extends, and the electric control device is electrically connected to the heating electrode; The gas collecting port is connected to a flue gas purification system; The flue gas purification system includes a quenching tower, a bag dust collector, an induced draft fan and a chimney. The inlet of the quenching tower is connected to the gas collecting port, the outlet of the quenching tower is connected to the inlet of the bag dust collector, the outlet of the bag dust collector is connected to the inlet of the induced draft fan, and the outlet of the induced draft fan is connected to the inlet of the chimney.

2. The molten salt furnace device according to claim 1, characterized in that: The molten salt furnace device also includes a feeding mechanism, which includes a first conveying cylinder, a first shaftless screw and a first rotating driving member. A first feeding port is opened at one end of the first conveying cylinder, and a first discharge port is opened at the other end of the first conveying cylinder. The first shaftless screw is rotatably arranged in the first conveying cylinder, and the first rotating driving member is connected to the first shaftless screw and is used to drive the first shaftless screw to rotate.

3. The molten salt furnace device according to claim 2, characterized in that: The feeding mechanism further comprises a hopper, wherein the hopper is used to store the formulated materials, and an outlet of the hopper is connected to the first feeding port.

4. The molten salt furnace device according to claim 3, characterized in that: The outlet of the hopper is provided with a discharge valve.

5. The molten salt furnace device according to claim 2, characterized in that: The first rotating driving member includes a first motor and a first reducer, the output end of the first motor is connected to the input end of the first reducer, and the output end of the first reducer is connected to the first shaftless screw.

6. The molten salt furnace device according to claim 1, characterized in that: The molten salt furnace further comprises an overflow pipe, which is arranged vertically, the lower end of which is communicated with the molten salt overflow port, and the upper end of which is used for allowing the overflow molten salt in the molten salt furnace to flow out.

7. The molten salt furnace device according to claim 1, characterized in that: The molten salt furnace device also includes a rapid cooling water quenching mechanism, which is used to quench the molten slag discharged from the molten salt furnace to form glass particles.

8. The molten salt furnace device according to claim 7, characterized in that: The rapid cooling water quenching mechanism includes a water quenching pool, a slag scooping machine and a heat exchange tube row. The water quenching pool is arranged below the molten slag discharge port, and the slag scooping machine and the heat exchange tube are integrated in the water quenching pool.

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