Phosphogypsum decomposition equipment capable of preventing high-temperature corrosion

Abstract

The utility model discloses ardealite decomposition equipment capable of preventing high-temperature corrosion, which belongs to the technical field of ardealite decomposition equipment and comprises a decomposition furnace and a heating burner, the decomposition furnace is hollow to form a decomposition cavity, a tail gas pipe communicated with the decomposition cavity and a blanking hopper are arranged at the top of the decomposition furnace, and a slag pipe communicated with the decomposition cavity is arranged at the bottom of the decomposition furnace. The decomposing furnace is sleeved with an air chamber, an air cavity is formed between the air chamber and the decomposing furnace, an air pipe communicated with the air cavity is arranged at the top of the air chamber, the air chamber is sleeved with a smoke chamber, a smoke cavity is formed between the smoke chamber and the air chamber, a smoke pipe communicated with the smoke chamber is arranged at the top of the smoke chamber, and an air inlet pipe communicated with the air cavity is arranged at the bottom of the air chamber; the end part of the gas inlet pipe is fixedly connected with the heating burner, the heating burner is provided with a radiant tube which penetrates through the decomposing furnace and extends into the decomposing cavity, and the end part of the radiant tube penetrates through the decomposing furnace and the air chamber and extends into the flue gas cavity; the device can prevent the inner wall of the decomposing furnace from hot corrosion caused by overhigh temperature.

Description

Technical Field

[0001] The utility model relates to the technical field of phosphogypsum decomposition equipment, in particular to phosphogypsum decomposition equipment which is resistant to high-temperature corrosion. Background Art

[0002] Phosphogypsum is an industrial waste residue generated during the production of phosphoric acid. The random discharge and accumulation of phosphogypsum has seriously damaged the ecological environment, not only polluting groundwater resources, but also causing waste of land resources. Phosphogypsum can be treated by heat treatment and the treated product can be utilized to turn waste into treasure. Common heat treatment methods include static reduction method based decomposition of phosphogypsum. Phosphogypsum, coal and other additives are mixed in a certain proportion and ground, and then sent to a static reduction decomposition furnace for calcination and decomposition. Under a reducing atmosphere, phosphogypsum decomposes to produce sulfur dioxide gas and calcium oxide. Sulfur dioxide gas can be used to make sulfuric acid, while calcium oxide can be used as a raw material for cement production. The high-temperature gas discharged from the furnace can also be used for power generation to achieve energy recovery. Although the heat treatment method is more efficient in treating phosphogypsum, the disadvantage of this method is also obvious, that is, it consumes a lot of energy, and the heat in the calcination process, together with sulfur dioxide and water vapor, will cause serious thermal corrosion to the decomposition furnace. Therefore, the heat treatment method for treating phosphogypsum has very high requirements for the corrosion protection of the decomposition furnace.

[0003] The Chinese patent with the publication number CN201254457Y discloses a static reduction method to decompose phosphogypsum to produce sulfuric acid and generate electricity and cement. The device is a static reduction decomposition furnace, which is composed of a furnace body, a discharge bin, a discharge ladle, an exhaust gas pipeline, a crusher and discharger, a discharge bin, and a crusher main shaft. The discharge bin is connected to the discharge ladle, and they and the exhaust gas pipeline are placed in the upper part of the furnace body. The crusher and discharger is inside the furnace body and connected to the crusher main shaft, and the discharge bin is placed in the lower part of the furnace body. The device decomposes phosphogypsum by calcining it, and the sulfur dioxide produced after the decomposition of the phosphogypsum is passed through After purification, it can be used to make sulfuric acid, and the calcined slag can be used to produce cement, realizing the resource utilization of phosphogypsum. However, phosphogypsum needs to be decomposed in an environment of 1100-1300℃. Even if the decomposition equipment of phosphogypsum is made of high-temperature resistant and corrosion-resistant materials, the exhaust gas containing sulfur dioxide, water vapor and other components generated during the decomposition of phosphogypsum will accelerate the thermal corrosion of the decomposition equipment under the action of high temperature, thereby causing the decomposition equipment to age too quickly and even causing exhaust gas leakage to pollute the environment. Therefore, it is necessary to improve the thermal corrosion resistance of phosphogypsum decomposition equipment. Utility Model Content

[0004] In view of the technical defects existing in the background technology, the utility model proposes a high-temperature corrosion-resistant phosphogypsum decomposition equipment, which solves the above technical problems and meets the actual needs. The specific technical solution is as follows:

[0005] A high-temperature corrosion-resistant phosphogypsum decomposition device comprises a decomposition furnace and a heating burner. The decomposition furnace is hollow inside to form a decomposition chamber. The top of the decomposition furnace is provided with an exhaust pipe and a lower hopper connected to the decomposition chamber. The bottom of the decomposition furnace is provided with a slag pipe connected to the decomposition chamber.

[0006] The decomposition furnace is provided with an air chamber outside the outer shell, an air cavity is formed between the air chamber and the decomposition furnace, and an air pipe connected to the air cavity is provided on the top of the air chamber; the air chamber is provided with a smoke chamber outside the outer shell, a smoke cavity is formed between the smoke chamber and the air chamber, and a smoke pipe connected to the smoke cavity is provided on the top of the smoke chamber;

[0007] An air inlet pipe communicating with the air cavity is provided at the bottom of the air chamber, and the end of the air inlet pipe is fixedly connected to the heating burner. The heating burner is provided with a radiation tube that penetrates the decomposition furnace and extends into the decomposition cavity, and the end of the radiation tube penetrates the decomposition furnace and the air chamber and extends into the smoke cavity.

[0008] As a further technical solution of the utility model, a first guide plate extending from the bottom to the top of the air chamber is provided in the air cavity, and the first guide plate is spirally wound along the outer surface of the decomposition furnace and the inner wall of the air chamber.

[0009] As a further technical solution of the utility model, a second guide plate extending from the bottom to the top of the smoke chamber is provided in the smoke cavity, and the second guide plate is spirally wound along the outer surface of the air chamber and the inner wall of the smoke chamber.

[0010] As a further technical solution of the utility model, the air pipe is sleeved outside the tail gas pipe, and the smoke pipe is sleeved outside the air pipe.

[0011] As a further technical solution of the utility model, a stirring paddle is provided in the decomposition chamber, and the stirring paddle is composed of a shaft and a plurality of blades on the shaft. The end of the shaft extends outside the decomposition furnace and is provided with a driving motor.

[0012] As a further technical solution of the utility model, a lower material gate extending into the lower material gate is provided on one side of the lower material hopper, and a slag gate extending into the slag material pipe is provided on one side of the slag material pipe.

[0013] As a further technical solution of the utility model, a bulk material plate is provided at the bottom of the lower hopper, the bulk material plate is located in the decomposition chamber, and a plurality of bulk material holes are penetrated through the surface of the bulk material plate.

[0014] As a further technical solution of the utility model, a heat insulation layer is provided on the outer cover of the smoke chamber.

[0015] The beneficial effects of the utility model are:

[0016] The utility model decomposes the phosphogypsum by heating the phosphogypsum through a heating burner based on a static reduction method. The heating burner adopts a radiation tube burner. The smoke generated when the heating burner burns will not be mixed with the tail gas of the decomposed phosphogypsum, and it is easier to recover the sulfur dioxide in the tail gas. At the same time, the combustion-supporting air flows through the surface of the decomposition furnace for heat exchange and then enters the heating burner for combustion, which can improve the combustion efficiency of the heating burner, reduce the temperature of the decomposition furnace body, prevent the inner wall of the decomposition furnace from thermal corrosion due to excessively high temperature, and improve the working life of the decomposition furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention is a structural schematic diagram of a phosphogypsum decomposition equipment which is resistant to high temperature corrosion.

[0018] Figure 2 It is a schematic diagram of the tail gas flow path of a high temperature corrosion resistant phosphogypsum decomposition equipment.

[0019] Figure 3 It is a schematic diagram of the combustion air flow path of a high-temperature corrosion-resistant phosphogypsum decomposition device.

[0020] Figure 4 It is a schematic diagram of the flue gas flow path of a high-temperature corrosion-resistant phosphogypsum decomposition device.

[0021] Figure 5 yes Figure 1 Schematic diagram at A in the middle.

[0022] Among them: decomposition furnace 1, decomposition chamber 11, tail gas pipe 12, heating burner 2, radiation tube 21, discharge hopper 3, discharge gate 31, bulk plate 32, bulk hole 33, slag pipe 4, slag gate 41, air chamber 5, air cavity 51, air pipe 52, air inlet pipe 53, first guide plate 54, smoke chamber 6, smoke cavity 61, smoke pipe 62, second guide plate 63, stirring paddle 7, shaft 71, paddle 72, drive motor 8, insulation layer 9. DETAILED DESCRIPTION

[0023] The implementation methods of the present invention are described below in conjunction with the accompanying drawings and relevant embodiments. The implementation methods of the present invention are not limited to the following embodiments, and the present invention involves relevant necessary components in this technical field, which should be regarded as common knowledge in this technical field and can be known and mastered by technical personnel in this technical field.

[0024] like Figure 1-4 As shown, a high-temperature corrosion-resistant phosphogypsum decomposition device comprises a decomposition furnace 1 and a heating burner 2. The decomposition furnace 1 is hollow inside to form a decomposition chamber 11. The top of the decomposition furnace 1 is provided with an exhaust pipe 12 and a lower hopper 3 connected to the decomposition chamber 11. The bottom of the decomposition furnace 1 is provided with a slag pipe 4 connected to the decomposition chamber 11.

[0025] An air chamber 5 is provided outside the decomposition furnace 1, an air cavity 51 is formed between the air chamber 5 and the decomposition furnace 1, an air pipe 52 connected to the air cavity 51 is provided on the top of the air chamber 5; a smoke chamber 6 is provided outside the air chamber 5, a smoke cavity 61 is formed between the smoke chamber 6 and the air chamber 5, a smoke pipe 62 connected to the smoke cavity 61 is provided on the top of the smoke chamber 6;

[0026] An air inlet pipe 53 communicating with the air cavity 51 is provided at the bottom of the air chamber 5. The end of the air inlet pipe 53 is fixedly connected to the heating burner 2. The heating burner 2 is provided with a radiation tube 21 penetrating the decomposition furnace 1 and extending into the decomposition cavity 11. The end of the radiation tube 21 penetrates the decomposition furnace 1 and the air chamber 5 and extends into the smoke cavity 61.

[0027] The working principle of the utility model is based on the static reduction method and is used to decompose phosphogypsum. After mixing phosphogypsum, coal, anti-caking agent, dispersant, etc. in proportion, the raw materials are ground by a grinding device to obtain raw materials of a certain fineness. The raw materials enter the decomposition chamber 11 inside the decomposition furnace 1 through the lower hopper 3. The lower hopper 3 adopts the shape of a funnel, and the opening at the bottom is connected to the raw material inlet at the top of the decomposition furnace 1 that allows the raw materials to enter. The lower hopper 3 can guide the raw materials entering from the top opening to the bottom opening and enter the decomposition chamber 11 from the raw material inlet. When the decomposition chamber 11 is filled with a set amount of raw materials, the raw material inlet is closed; the air pipe 52 An air inlet is provided at one end away from the air chamber 5, and the air inlet is connected to external pipelines and equipment such as blowers. The blower transports the combustion air along the pipeline to the air inlet and then enters the air pipe 52. The combustion air then leaves the air pipe 52 and enters the air cavity 51 in the air chamber 5. Finally, the combustion air leaves the air cavity 51 and enters the heating burner 2 along the air inlet pipe 53 to mix with the fuel gas and burn through ignition. The heat generated during combustion heats the raw materials in the decomposition chamber 11 through the radiation tube 21 to decompose the phosphogypsum. After the phosphogypsum is decomposed, physical slag will be produced, which is discharged through the slag pipe 4 and can be used to produce cement.

[0028] The decomposition of phosphogypsum produces tail gas containing components such as sulfur dioxide and water vapor. The tail gas leaves from the tail gas pipe 12 and is transported to the purification equipment to remove impurities and purify the tail gas to obtain high-purity sulfur dioxide and use it to make sulfuric acid. The waste heat contained in the tail gas can be used for power generation. The flue gas generated by the combustion in the heating burner 2 enters the smoke cavity 61 of the smoke chamber 6 from the end of the radiation tube 21, and then the smoke gas leaves the smoke cavity 61 from the smoke pipe 62 and is transported to the external recovery and treatment equipment. The smoke gas can be discharged only after it meets the emission standards after recovery and treatment. The waste heat contained in the flue gas can also be used for power generation. The heating burner 2 of the utility model adopts a radiation tube burner. The operating temperature of the radiation tube burner can reach 1300°C, which meets the requirements of the static reduction method for decomposing phosphogypsum. Compared with the conventional open flame calcination method for decomposing phosphogypsum, the flue gas generated by the combustion in the heating burner 2 will not be mixed with the tail gas decomposed by the phosphogypsum, which can reduce the content of impurity gases in the tail gas, thereby making it easier to extract sulfur dioxide from the tail gas.

[0029] When the combustion air flows through the air cavity 51, it will contact the outer surface of the decomposition furnace 1 and exchange heat with it, thereby reducing the temperature of the main material of the decomposition furnace 1, thereby preventing the inner wall of the decomposition furnace 1 from thermal corrosion due to excessive temperature, and increasing the working life of the decomposition furnace 1. This process has a slight effect on the temperature of the raw materials in the decomposition chamber 11 and will not affect the decomposition of phosphogypsum. In addition, the temperature of the combustion air rises after the heat exchange, which can improve the combustion efficiency of the heating burner 2. The flue gas can pass through the air chamber 5 in the flue gas cavity 61 to exchange heat with the combustion air in the air cavity 51, further increasing the temperature of the combustion air to improve the combustion efficiency of the heating burner 2, and recovering part of the waste heat in the flue gas to improve energy utilization.

[0030] Furthermore, the radiation tube 21 can be spirally wound in the decomposition chamber 11 to form a shape similar to a truncated cone or a cylinder, which can increase the contact area between the radiation tube 21 and the raw material and improve the decomposition efficiency of the phosphogypsum.

[0031] like Figure 1-5 As shown, as one of the preferred embodiments of the utility model, a first guide plate 54 extending from the bottom to the top of the air chamber 5 is provided in the air cavity 51, and the first guide plate 54 is spirally wound along the outer surface of the decomposition furnace 1 and the inner wall of the air chamber 5.

[0032] The first guide plate 54 of the utility model is used to guide the flow path of the combustion air in the air cavity 51. The combustion air flows in a spiral path under the guidance of the first guide plate 54, which can extend the flow path and time of the combustion air in the air cavity 51, and increase the contact time between the combustion air and the outer surface of the decomposition furnace 1. The combustion air can fully exchange heat with the decomposition furnace 1 body, so that the combustion air can absorb more heat in the decomposition furnace 1 body, further reducing the thermal corrosion of the decomposition furnace 1 by high temperature.

[0033] like Figure 1-5 As shown, as one of the preferred embodiments of the utility model, a second guide plate 63 extending from the bottom to the top of the smoke chamber 6 is provided in the smoke cavity 61, and the second guide plate 63 is spirally wound along the outer surface of the air chamber 5 and the inner wall of the smoke chamber 6.

[0034] The second guide plate 63 of the utility model is used to guide the flow path of the smoke in the smoke chamber 61. The smoke flows in a spiral path under the guidance of the second guide plate 63, which can extend the flow path and time of the smoke in the smoke chamber 61, and increase the contact time between the smoke and the outer surface of the air chamber 5. The smoke can fully exchange heat with the combustion air in the air chamber 51, so that the combustion air can absorb more waste heat in the smoke, further improving energy utilization.

[0035] like Figure 1 As shown, as one of the preferred embodiments of the utility model, the air pipe 52 is sleeved outside the tail gas pipe 12 , and the smoke pipe 62 is sleeved outside the air pipe 52 .

[0036] In the present invention, the structure in which the air pipe 52 is put on the outside of the exhaust pipe 12 and the smoke pipe 62 is put on the outside of the air pipe 52 can be regarded as a heat exchange structure. The combustion air can exchange heat with the exhaust gas and the smoke gas through the exhaust pipe 12 and the air pipe 52 respectively. The combustion air absorbs the residual heat in the exhaust gas and the smoke gas. The combustion air has just been sent into the air pipe 52 through the blower. The temperature of the combustion air in the air pipe 52 is still in a relatively low state, the heat exchange efficiency is relatively high, and the energy utilization rate can be improved.

[0037] like Figure 1 As shown, as one of the preferred embodiments of the utility model, a stirring paddle 7 is provided in the decomposition chamber 11. The stirring paddle 7 is composed of a shaft 71 and a plurality of blades 72 on the shaft 71. The end of the shaft 71 extends to the outside of the decomposition furnace 1 and is provided with a driving motor 8.

[0038] The driving motor 8 of the utility model is connected to the external power supply line through a power supply cable, and the driving motor 8 is operated by the electric energy provided by the power supply line. When the driving motor 8 is in operation, the driving shaft 71 is driven to rotate, and the shaft 71 rotates to drive the blades 72 to rotate synchronously, that is, the stirring paddle 7 is driven by the driving motor 8 to rotate. When the heating burner 2 heats the raw materials, the raw materials can be stirred by rotating the stirring paddle 7 to avoid agglomeration during the decomposition of the phosphogypsum.

[0039] like Figure 1 As shown, as one of the preferred embodiments of the utility model, a lower hopper 3 is provided with a lower sluice 31 extending into the lower hopper 3 on one side, and a slag sluice 41 extending into the slag sluice 4 is provided on one side of the slag pipe 4 .

[0040] The discharge gate 31 is used to control the opening or closing of the channel in the discharge hopper 3. When the discharge hopper 3 is opened, raw materials can be added into the decomposition furnace 1. When the discharge hopper 3 is closed, exhaust gas generated by the decomposition of phosphogypsum can be prevented from being discharged from the discharge hopper 3. The slag gate 41 is used to control the opening or closing of the slag pipe 4. When the raw materials in the decomposition furnace 1 complete the reaction, the slag pipe 4 is opened to discharge the slag. When the slag pipe 4 is closed, the discharge of raw materials can be prevented.

[0041] like Figure 1 As shown, as one of the preferred embodiments of the utility model, a bulking plate 32 is provided at the bottom of the lower hopper 3, the bulking plate 32 is located in the decomposition chamber 11, and a plurality of bulking holes 33 are penetrated on the surface of the bulking plate 32.

[0042] The bulk plate 32 of the utility model is an annular structure and has a truncated cone shape. A through hole coaxial with the lower hopper 3 is provided at the axis center of the bulk plate 32. The diameter of one end of the bulk plate 32 close to the lower hopper 3 is smaller than that of the other end. After the raw materials enter the decomposition chamber 11 through the lower hopper 3, part of the raw materials will directly fall to the bottom of the decomposition chamber 11 through the through hole of the bulk plate 32, and the other part of the raw materials will slide downward through the beveled edge of the side of the bulk plate 32. During the sliding process, they will gradually fall to the bottom of the decomposition chamber 11 through the bulk hole 33 and the bottom edge of the bulk plate 32, thereby dispersing the raw materials to the bottom of the decomposition chamber 11 through the bulk plate 32, thereby preventing the raw materials from accumulating at the bottom of the decomposition chamber 11 and affecting the decomposition efficiency.

[0043] like Figure 1 As shown, as one of the preferred embodiments of the utility model, the smoke chamber 6 is outer-coated with a heat-insulating layer 9 .

[0044] The heat insulation layer 9 of the utility model can be made of polystyrene board, rock wool, glass wool, polyurethane foam material, vacuum insulation material, etc. The heat insulation layer 9 is wrapped outside the decomposition equipment to reduce the transfer and loss of heat and improve the thermal efficiency of the decomposition equipment.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A high temperature corrosion resistant phosphogypsum decomposition device, comprising a decomposition furnace (1) and a heating burner (2), characterized in that: The decomposition furnace (1) is hollow inside to form a decomposition chamber (11); a tail gas pipe (12) and a lower hopper (3) in communication with the decomposition chamber (11) are provided at the top of the decomposition furnace (1); and a slag pipe (4) in communication with the decomposition chamber (11) is provided at the bottom of the decomposition furnace (1); The decomposition furnace (1) is provided with an air chamber (5) on its outer casing, an air cavity (51) is formed between the air chamber (5) and the decomposition furnace (1), and an air pipe (52) communicating with the air cavity (51) is provided at the top of the air chamber (5); a smoke chamber (6) is provided on its outer casing, a smoke cavity (61) is formed between the smoke chamber (6) and the air chamber (5), and a smoke pipe (62) communicating with the smoke cavity (61) is provided at the top of the smoke chamber (6); An air inlet pipe (53) communicating with the air cavity (51) is provided at the bottom of the air chamber (5); an end of the air inlet pipe (53) is fixedly connected to the heating burner (2); the heating burner (2) is provided with a radiation tube (21) penetrating the decomposition furnace (1) and extending into the decomposition cavity (11); an end of the radiation tube (21) penetrates the decomposition furnace (1) and the air chamber (5) and extends into the smoke cavity (61).

2. The high temperature corrosion resistant phosphogypsum decomposition equipment according to claim 1, characterized in that: A first guide plate (54) extending from the bottom to the top of the air chamber (5) is provided in the air cavity (51), and the first guide plate (54) is spirally wound along the outer surface of the decomposition furnace (1) and the inner wall of the air chamber (5).

3. The high temperature corrosion resistant phosphogypsum decomposition equipment according to claim 1, characterized in that: A second guide plate (63) extending from the bottom to the top of the smoke chamber (6) is provided in the smoke cavity (61), and the second guide plate (63) is spirally wound along the outer surface of the air chamber (5) and the inner wall of the smoke chamber (6).

4. The high temperature corrosion resistant phosphogypsum decomposition equipment according to claim 1, characterized in that: The air pipe (52) is sleeved outside the tail gas pipe (12), and the flue gas pipe (62) is sleeved outside the air pipe (52).

5. The high temperature corrosion resistant phosphogypsum decomposition equipment according to claim 1, characterized in that: A stirring paddle (7) is provided in the decomposition chamber (11), and the stirring paddle (7) is composed of a shaft (71) and a plurality of paddle blades (72) on the shaft (71). The end of the shaft (71) extends outside the decomposition furnace (1) and is provided with a driving motor (8).

6. The high temperature corrosion resistant phosphogypsum decomposition equipment according to claim 1, characterized in that: A material discharge gate (31) extending into the interior of the material discharge hopper (3) is provided on one side of the material discharge hopper (3), and a slag gate (41) extending into the interior of the slag pipe (4) is provided on one side of the slag pipe (4).

7. The high temperature corrosion resistant phosphogypsum decomposition equipment according to claim 1, characterized in that: A bulk material plate (32) is provided at the bottom of the lower hopper (3); the bulk material plate (32) is located in the decomposition chamber (11); and a plurality of bulk material holes (33) are penetrated through the surface of the bulk material plate (32).

8. The high temperature corrosion resistant phosphogypsum decomposition equipment according to claim 1, characterized in that: The smoke chamber (6) is provided with a heat insulation layer (9) on its outer jacket.

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