A waste heat recovery device for sodium silicate kiln flue gas

Abstract

This utility model discloses a waste heat recovery device for flue gas from a sodium silicate kiln, comprising a waste heat recovery assembly and a spray tower. The waste heat recovery assembly includes a primary waste heat recovery unit and a secondary waste heat recovery unit. The primary waste heat recovery unit has a flue gas inlet pipe on one side and multiple primary heat exchange units inside. A connecting pipe is provided on the other side of the primary waste heat recovery unit. The secondary waste heat recovery unit has a secondary heat exchange unit inside, which is connected to the connecting pipe. A water inlet pipe is provided at the bottom of the secondary waste heat recovery unit, and a water outlet pipe is provided at the top. A flue gas outlet pipe is provided on the side of the secondary waste heat recovery unit away from the connecting pipe. By setting up a primary waste heat recovery unit and a secondary waste heat recovery unit, this utility model can recover waste heat in the flue gas in stages. Compared with the traditional single waste heat recovery structure, it greatly improves the waste heat recovery efficiency, makes full use of the heat in the flue gas, and reduces energy waste.

Description

Technical Field

[0001] This utility model relates to the field of flue gas waste heat recovery, and in particular to a waste heat recovery device for sodium silicate kiln flue gas. Background Technology

[0002] Sodium silicate, commonly known as sodium silicate, is a water-soluble silicate with advantages such as strong adhesion, high strength, acid resistance, and good heat resistance. It is widely used in analytical reagents, fire retardants, adhesives, and as a raw material for the production of inorganic silicon compounds, such as precipitated silica, silica gel, sodium metasilicate, silica sol, and molecular sieves. Industrially, sodium silicate is mainly produced by melting and reacting quartz sand and soda ash at a high temperature of 1300–1400℃ to produce solid sodium silicate. The solid sodium silicate then flows out from the kiln outlet, is cooled and formed into blocks, or quenched in water to obtain solid sodium silicate. To obtain liquid sodium silicate, steam and water are introduced and dissolved under high temperature and high pressure conditions.

[0003] During the melting reaction of sodium silicate in a kiln, a large amount of high-temperature flue gas is generated. This flue gas usually undergoes preliminary waste heat recovery. If the large amount of waste heat contained in the high-temperature flue gas can be recovered and utilized in a gradient and efficient manner, the waste of thermal energy can be greatly reduced. Summary of the Invention

[0004] In view of this, the purpose of this utility model is to propose a waste heat recovery device for flue gas from sodium silicate kilns.

[0005] To achieve the above-mentioned technical objectives, the technical solution adopted by this utility model is as follows:

[0006] A waste heat recovery device for flue gas from a sodium silicate kiln includes a waste heat recovery assembly and a spray tower. The waste heat recovery assembly includes a primary waste heat recovery unit and a secondary waste heat recovery unit. The primary waste heat recovery unit has a flue gas inlet pipe on one side and multiple primary heat exchange units inside. The other side of the primary waste heat recovery unit has a connecting pipe. The secondary waste heat recovery unit has a secondary heat exchange unit inside and is connected to the connecting pipe. The secondary waste heat recovery unit has a water inlet pipe at the bottom and a water outlet pipe at the top. The side of the secondary waste heat recovery unit away from the connecting pipe has a flue gas outlet pipe. The spray tower is connected to the secondary waste heat recovery unit through the flue gas outlet pipe. The spray tower has a spray assembly and a hot water recovery tank inside. The hot water recovery tank is located below the spray assembly and is connected to the spray assembly.

[0007] Preferably, the primary heat exchange unit is a spiral heat exchange tube, and the inlets of the plurality of spiral heat exchange tubes extend out of the bottom wall of the primary waste heat recovery unit and are connected to the low-temperature inlet water pipe, and the outlets of the plurality of spiral heat exchange tubes extend out of the top wall of the primary waste heat recovery unit and are connected to the high-temperature outlet water pipe.

[0008] Preferably, the secondary heat exchange unit is an S-shaped heat exchange tube, with both ends of the S-shaped heat exchange tube connected to the connecting pipe and the flue gas outlet pipe, respectively, and the water inlet pipe of the secondary waste heat recovery unit connected to the low-temperature water inlet pipe.

[0009] Preferably, the low-temperature water inlet pipe is equipped with a regulating valve, which is used to regulate the amount of low-temperature water flowing into the spiral heat exchanger tube.

[0010] Preferably, the spray assembly includes a spray pipe and a plurality of spray heads, wherein the plurality of spray heads are distributed at the lower end of the spray pipe and are connected to the spray pipe.

[0011] Preferably, a circulating water pump is connected to one side of the hot water recovery tank, and the circulating water pump is connected to the low-temperature water inlet pipe and the spray pipe.

[0012] Preferably, the spray tower is provided with a filter plate, which is disposed between the spray assembly and the hot water recovery tank, and there are multiple filter plates, all of which are inclined.

[0013] Preferably, a diversion bucket is provided below the filter plate, and the outlet end of the diversion bucket is connected to the hot water recovery tank.

[0014] Preferably, the primary waste heat recovery unit is equipped with a dust filter screen, which is located on both sides of the primary heat exchange unit and is concave.

[0015] By adopting the above technical solution, the beneficial effects of this utility model compared with the prior art are as follows:

[0016] The advantages of the above technical solution, which differs from existing technologies, are as follows: By setting up a primary waste heat recovery unit and a secondary waste heat recovery unit, the present invention can recover the waste heat in the flue gas in stages. Compared with the traditional single waste heat recovery structure, this greatly improves the waste heat recovery efficiency, makes full use of the heat in the flue gas, and reduces energy waste. After the secondary heat exchange, the flue gas enters the spray tower and exchanges heat with the spray water, recovering the remaining heat in the flue gas again, thus achieving comprehensive recovery and utilization of the waste heat in the flue gas. The spray tower can spray and purify the flue gas, effectively removing residual dust and other pollutants from the flue gas and reducing the pollution of the flue gas to the environment. At the same time, the hot water recovery tank is connected to the spray pipe through a circulating pump, realizing the recycling of spray water, reducing water consumption, and lowering the operating cost. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the primary waste heat recovery unit and the secondary waste heat recovery unit described in this embodiment;

[0019] Figure 2 This is a schematic diagram of the spray tower described in this embodiment;

[0020] Figure 3 This is a schematic diagram of multiple spiral heat exchange tubes described in this embodiment.

[0021] The reference numerals used in the above figures are explained as follows:

[0022] 1. Waste heat recovery assembly; 11. Primary waste heat recovery unit; 111. Flue gas inlet pipe; 112. Spiral heat exchanger tube; 1121. Water outlet; 1122. Water inlet; 113. Connecting pipe; 114. Dust filter screen; 12. Secondary waste heat recovery unit; 121. S-type heat exchanger tube; 122. Water inlet pipe; 123. Water outlet pipe; 124. Flue gas outlet pipe; 2. Spray tower; 21. Spray assembly; 211. Spray pipe; 212. Spray head; 22. Hot water recovery tank; 23. Filter plate; 24. Diversion hopper; 25. Circulating water pump; 251. Hot water outlet; 3. Low temperature water inlet pipe; 31. Regulating valve; 4. High temperature water outlet pipe. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be particularly noted that the following embodiments are only for illustrating the present invention and do not limit the scope of the present invention. Similarly, the following embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0024] Please see Figures 1 to 3This embodiment provides a waste heat recovery device for flue gas from a sodium silicate kiln, including a waste heat recovery component 1 and a spray tower 2. The waste heat recovery component 1 includes a primary waste heat recovery unit 11 and a secondary waste heat recovery unit 12. The primary waste heat recovery unit 11 has a flue gas inlet pipe 111 on one side and multiple primary heat exchange units inside. The other side of the primary waste heat recovery unit 11 has a connecting pipe 113. The secondary waste heat recovery unit 12 has a secondary heat exchange unit inside, which is connected to the connecting pipe 113. The bottom of the secondary waste heat recovery unit 12 has a water inlet pipe 122 and the top has a water outlet pipe 123. The side of the secondary waste heat recovery unit 12 away from the connecting pipe 113 has a flue gas outlet pipe 124. The spray tower 2 is connected to the secondary waste heat recovery unit 12 through the flue gas outlet pipe 124. The spray tower 2 has a spray component 21 and a hot water recovery tank 22 inside. The hot water recovery tank 22 is located below the spray component 21 and is connected to the spray component 21.

[0025] The primary waste heat recovery unit 11 is made of insulation material and is a shell structure with a certain volume. The inlet pipe 111 on one side is the channel for high-temperature flue gas to enter, and multiple primary heat exchange units installed inside are used for preliminary heat exchange with the high-temperature flue gas. The connecting pipe 113 on the other side is used to transport the flue gas after one heat exchange to the secondary waste heat recovery unit 12. The secondary heat exchange units inside the secondary waste heat recovery unit 12 are connected to the connecting pipe 113, receiving the flue gas from the primary waste heat recovery unit 11 and performing a second heat exchange. The bottom water inlet pipe 122 is used to introduce low-temperature water, and the top water outlet pipe 123 is used to discharge the water after heat exchange. The flue gas outlet pipe 124 on the side away from the connecting pipe 113 transports the flue gas after a second heat exchange to the spray tower 2. The inlet pipe 111 is a tubular structure made of high-temperature resistant stainless steel, and its outer surface is wrapped with insulation material to prevent the high-temperature flue gas from exchanging heat with the outside air during transportation, thus preventing the loss of waste heat in the flue gas. One end of the flue gas inlet pipe 111 is connected to the flue gas outlet of the sodium silicate kiln, and the other end is connected to the primary waste heat recovery unit 11, used to introduce the high-temperature flue gas generated by the kiln into the primary waste heat recovery unit 11. Multiple primary heat exchange units are evenly distributed along a direction perpendicular to the flow of the high-temperature flue gas. Each primary heat exchange unit is a component that realizes heat exchange between the high-temperature flue gas and the low-temperature water, transferring heat from the flue gas to the low-temperature water and recovering the heat from the high-temperature flue gas. The connecting pipe 113 is a tubular structure made of the same material as the flue gas inlet pipe 111, and its outer surface is also covered with a layer of insulation material. The two ends of the connecting pipe 113 are connected to the primary waste heat recovery unit 11 and the secondary waste heat recovery unit 12, respectively, used to transport the flue gas that has undergone primary heat exchange to the secondary waste heat recovery unit. The secondary heat exchange unit is made of a metal material with excellent thermal conductivity, used to receive the flue gas transported from the connecting pipe 113 and exchange heat with the low-temperature water in the secondary waste heat recovery unit 12, recovering the waste heat from the flue gas. The spray tower 2 is a tower-shaped device with a cavity. It is connected to the secondary waste heat recovery unit 12 via the flue gas outlet pipe 124. It is used to spray and purify the incoming flue gas and perform three heat exchanges on the flue gas to completely recover the waste heat in the flue gas. The hot water recovery tank 22 is used to collect the water after spraying and is connected to the spray assembly 21. The collected water can be reused to spray and treat the flue gas again, gradually increasing the temperature of the water in the hot water recovery tank 22.

[0026] Specifically, the high-temperature flue gas generated by the kiln enters the primary waste heat recovery unit 11 through the flue gas inlet pipe 111. Inside the primary waste heat recovery unit 11, the high-temperature flue gas contacts the primary heat exchange unit, transferring heat to the low-temperature water within the unit, completing the first stage of waste heat recovery from the flue gas. After the first heat exchange, the flue gas temperature decreases, and it then enters the secondary heat exchange unit of the secondary waste heat recovery unit 12 through the connecting pipe 113. Simultaneously, the low-temperature water enters the secondary waste heat recovery unit 12 through the water inlet pipe 122, exchanging heat with the flue gas in the secondary heat exchange unit, achieving the second stage of waste heat recovery. After heat exchange with the flue gas, the low-temperature water temperature in the secondary waste heat recovery unit 12 increases, and it flows out from the water outlet pipe 123. The flue gas temperature decreases further after the second heat exchange, and it enters the spray tower 2 through the flue gas outlet pipe 124. Inside the spray tower 2, the spray assembly 21 sprays the flue gas to remove residual dust and other impurities. The sprayed water falls into the hot water recovery tank 22 below, which then supplies the collected water to the spray assembly 21, thus enabling the recycling of the spray water.

[0027] Compared with existing technologies, this embodiment, by setting up a primary waste heat recovery unit 11 and a secondary waste heat recovery unit 12, can recover waste heat in flue gas in stages. Compared with the traditional single recovery structure, it greatly improves the waste heat recovery efficiency, makes full use of the heat in the flue gas, and reduces energy waste. After secondary heat exchange, the flue gas enters the spray tower 2 and exchanges heat with the spray water, recovering the remaining heat in the flue gas again, realizing the comprehensive recovery and utilization of waste heat in the flue gas. The spray tower 2 can spray and purify the flue gas, effectively removing pollutants such as dust in the flue gas and reducing the pollution of the flue gas to the environment. At the same time, the hot water recovery tank 22 is connected to the spray assembly 21, realizing the recycling of spray water, reducing water consumption and lowering the operating cost.

[0028] Please see Figure 1 and Figure 3In this embodiment, the primary heat exchange unit is a spiral heat exchange tube 112. The inlets 1122 of multiple spiral heat exchange tubes 112 extend from the bottom wall of the primary waste heat recovery unit 11 and communicate with the low-temperature water inlet pipe 3. The outlets 1121 of multiple spiral heat exchange tubes 112 extend from the top wall of the primary waste heat recovery unit 11 and communicate with the high-temperature water outlet pipe 4. The spiral heat exchange tube 112 is a tubular heat exchange component with a spiral bend. Its spiral structure increases the contact area and contact time with the flue gas, improving the heat exchange effect. Simultaneously, the spiral heat exchange tube 112 is made of a material with excellent thermal conductivity, enabling rapid transfer of heat from the flue gas to the low-temperature water within the spiral heat exchange tube 112, thus realizing the recovery of waste heat from the flue gas. The inlets 1122 of the spiral heat exchange tube 112 are the ports for introducing low-temperature water into the spiral heat exchange tube 112, located at the lower end of the spiral heat exchange tube 112 and extending from the bottom wall of the primary waste heat recovery unit 11. One end of the low-temperature inlet pipe 3 is connected to a low-temperature water source, used to transport low-temperature water to multiple spiral heat exchange tubes 112. The outlet 1121 is used to discharge the high-temperature hot water after heat exchange. The high-temperature outlet pipe 4, connected to the outlet 1121, is used to transport the high-temperature hot water to equipment or storage devices that need hot water for use. Specifically, the spiral heat exchange tubes 112 are installed as a primary heat exchange unit in the primary waste heat recovery unit 11. When high-temperature flue gas enters the primary waste heat recovery unit 11 through the inlet pipe 111, it comes into full contact with the spiral heat exchange tubes 112. Low-temperature water is transported through the low-temperature inlet pipe 3 to the inlet 1122 of each spiral heat exchange tube 112 and enters the interior of the spiral heat exchange tubes 112. Inside the spiral heat exchange tubes 112, the low-temperature water exchanges heat with the high-temperature flue gas outside the tubes, absorbing heat from the flue gas and increasing in temperature. Due to the spiral structure of the spiral heat exchange tube 112, the flow path of the low-temperature water inside the tube and the contact time with the flue gas are extended, resulting in more thorough heat exchange. The high-temperature water after heat exchange flows into the high-temperature water outlet pipe 4 through the outlet 1121 and is then transported to the place where it is needed.

[0029] The spiral structure of the spiral heat exchange tube 112 increases the contact area with the flue gas, prolongs the heat exchange time, and improves the heat exchange efficiency of the primary waste heat recovery, enabling it to absorb heat from the high-temperature flue gas more fully. The simultaneous operation of multiple spiral heat exchange tubes 112 increases the overall heat exchange capacity, further enhancing the waste heat recovery effect and meeting greater heat demand. The low-temperature water inlet pipe 3 and the high-temperature water outlet pipe 4 are respectively centrally connected to the inlet 1122 and outlet 1121 of multiple spiral heat exchange tubes 112, facilitating centralized control and management of the low-temperature water flowing into the primary waste heat recovery box and the high-temperature water discharged from the primary waste heat recovery box.

[0030] Please see Figure 1In this embodiment, the secondary heat exchange unit is an S-shaped heat exchange tube 121. Both ends of the S-shaped heat exchange tube 121 are connected to the connecting pipe 113 and the flue gas outlet pipe 124, respectively. The inlet pipe 122 of the secondary waste heat recovery unit 12 is connected to the low-temperature inlet pipe 3. The S-shaped heat exchange tube 121 is an S-shaped tubular component made of a material with excellent thermal conductivity. The curved structure of the S-shaped heat exchange tube 121 extends the flow path of the flue gas inside the tube and the heat exchange time with the low-temperature water outside the tube. Simultaneously, it increases the heat exchange area between the flue gas and the low-temperature water, improving the recovery efficiency of the secondary waste heat recovery unit for the flue gas waste heat. Specifically, the S-shaped heat exchange tube 121 is installed as a secondary heat exchange unit inside the secondary waste heat recovery unit 12. One end is connected to the connecting pipe 113 to receive the flue gas from the primary waste heat recovery unit 11, and the other end is connected to the flue gas outlet pipe 124 to discharge the heat-exchanged flue gas. Meanwhile, the inlet pipe 122 of the secondary waste heat recovery unit 12 is connected to the low-temperature inlet pipe 3, and the low-temperature water enters the interior of the secondary waste heat recovery unit 12 from the inlet pipe 122. When the flue gas flows inside the S-shaped heat exchange tube 121, it exchanges heat with the low-temperature water outside the tube. The heat of the flue gas is transferred to the low-temperature water, causing the temperature of the low-temperature water to rise. Then, it is discharged from the outlet pipe 123 and transported to the place where hot water is needed, realizing the recovery and utilization of the waste heat of the flue gas. The "S"-shaped bending structure of the S-shaped heat exchange tube 121 extends the flow path of the flue gas inside the tube, increases the contact time between the flue gas and the low-temperature water, and improves the heat exchange effect.

[0031] The curved structure of the S-shaped heat exchange tube 121 increases the contact area and contact time between the flue gas and the low-temperature water in the secondary waste heat recovery unit 12, thereby improving the heat exchange efficiency of the secondary waste heat recovery and enabling further recovery of waste heat from the flue gas. The water inlet pipe 122 of the secondary waste heat recovery unit 12 is connected to the low-temperature water inlet pipe 3, allowing low-temperature water to be supplied to both the primary waste heat recovery unit 11 and the secondary waste heat recovery unit 12 simultaneously, simplifying the water supply system structure and facilitating centralized management and control. The waste heat of the flue gas after the primary waste heat recovery is recovered again, further reducing the emission temperature of the flue gas and maximizing the utilization of waste heat in the flue gas.

[0032] Please see Figure 1 and Figure 3In this embodiment, a regulating valve 31 is provided on the low-temperature water inlet pipe 3. The regulating valve 31 is used to regulate the amount of low-temperature water flowing into the spiral heat exchange tube 112. The regulating valve 31 is a control component installed on the low-temperature water pipe. By changing the opening degree of the regulating valve 31, the amount of low-temperature water flowing into the spiral heat exchange tube 112 is controlled. Here, "amount" refers to the volume or mass of low-temperature water entering the spiral heat exchange tube 112 through the low-temperature water inlet pipe 3 per unit time. Specifically, the regulating valve 31 is installed on the low-temperature water inlet pipe 3. When the flue gas temperature generated by the kiln is high, the opening degree of the regulating valve 31 can be increased to allow more low-temperature water to flow into the spiral heat exchange tube 112, avoiding insufficient heat exchange due to insufficient water volume, and also preventing the spiral heat exchange tube 112 from being damaged due to excessive temperature. When the flue gas temperature is low, the opening degree of the regulating valve 31 is decreased to reduce the amount of low-temperature water flowing into the spiral heat exchange tube 112, avoiding excessive low-temperature water that cannot fully absorb heat and causes energy waste. The regulating valve 31 can flexibly adjust the flow rate of low-temperature water into the spiral heat exchange tube 112 according to the change of flue gas temperature, ensuring good heat exchange effect under different flue gas temperature conditions, and improving the adaptability and flexibility of the device.

[0033] Please see Figure 2 In this embodiment, the spray assembly 21 includes a spray pipe 211 and multiple spray heads 212. The multiple spray heads 212 are distributed at the lower end of the spray pipe 211 and communicate with it. The spray pipe 211 is a tubular component installed inside the spray tower 2, used to transport spray water. Multiple interfaces are distributed along its pipeline for connecting to the spray heads 212. The spray heads 212 communicate with the spray pipe 211, enabling them to spray the water transported by the spray pipe 211 in the form of a mist, increasing the heat exchange area between the spray water and the flue gas, and improving heat exchange efficiency. Specifically, the spray pipe 211 is connected to an external water source and a hot water recovery tank 22. Spray water is transported to each spray head 212 through the spray pipe 211. When the flue gas enters the spray tower 2, the spray heads 212 spray water in the form of a water mist, allowing it to fully contact the flue gas for heat exchange and recovering waste heat from the flue gas. Simultaneously, dust and other impurities in the flue gas are adsorbed by water droplets and fall down with them, thus purifying the flue gas. Multiple spray heads 212 are distributed at the lower end of the spray pipe 211, ensuring that the spray range covers the entire flue gas flow cross-section and improving the purification effect. The distributed arrangement of multiple spray heads 212 expands the spray range, allowing the flue gas to fully contact the sprayed water, improving the removal efficiency of dust and other impurities in the flue gas, resulting in better purification. The spray heads 212 spray water in a mist form, increasing the heat exchange area between the water and the flue gas and improving the waste heat recovery efficiency of the flue gas.

[0034] Please see Figure 2In this embodiment, a circulating water pump 25 is connected to one side of the hot water recovery tank 22. The circulating water pump 25 is connected to the low-temperature water inlet pipe 3 and the spray pipe 211. The circulating water pump 25 is installed inside the spray tower 2, located on one side of the hot water recovery tank 22, and is connected to the hot water recovery tank 22, the low-temperature water inlet pipe 3, and the spray pipe 211. The circulating water pump 25 is also provided with a hot water outlet 251 for transporting the hot water in the hot water recovery tank 22 to other places for use. Specifically, the circulating water pump 25 is connected to the hot water recovery tank 22. When a certain amount of sprayed water is collected in the hot water recovery tank 22, the circulating water pump 25 starts, pumping the water out of the hot water recovery tank 22 and delivering it to the spray pipe 211. The water is then sprayed onto the flue gas again through the spray head 212, raising the temperature of the sprayed water. When the water temperature in the hot water recovery tank 22 reaches the expected temperature, the circulating water pump 25 pumps the hot water from the hot water outlet 251 and delivers it to the place where hot water is needed. At this time, the water in the spray pipe 211 is supplied by the low-temperature inlet pipe 3. The circulating water pump 25 delivers the water from the hot water recovery tank 22 to the spray pipe 211, realizing the recycling of water resources, significantly reducing the amount of fresh water used, and lowering water consumption and usage costs.

[0035] Please see Figure 2 In this embodiment, the spray tower 2 is equipped with filter plates 23, which are disposed between the spray assembly 21 and the hot water recovery tank 22. Multiple filter plates 23 are present, and all are inclined. The filter plates 23 have an activated carbon adsorption layer inside to adsorb dust particles and odors in the water. Multiple filter plates 23 are vertically distributed inside the spray tower 2 to filter impurities in the sprayed water layer by layer. Specifically, when the spray assembly 21 sprays the flue gas, the water containing dust and other impurities drips downwards, first landing on the filter plates 23. The filter plates 23 can block and adsorb dust and other impurities in the water, thus purifying the water. Because the filter plates 23 are inclined, the filtered water flows down along the inclined surface of the filter plates 23. Simultaneously, the inclined arrangement increases the flow path and residence time of the water on the filter plates 23, making the filtration more thorough. The multiple filter plates 23 further improve the filtration effect. After multiple layers of filtration, impurities in the water are effectively removed, ensuring the cleanliness of the water collected by the hot water recovery tank 22, preventing impurities from entering the circulating water pump 25 and spray pipe 211, causing blockage or damage, and extending the service life of the equipment.

[0036] Please see Figure 2In this embodiment, a guide bucket 24 is also provided below the filter plate 23, and the outlet end of the guide bucket 24 is connected to the hot water recovery tank 22. The guide bucket 24 is a funnel-shaped component installed below the filter plate 23, which guides the water flow, and its lower end has a water outlet. Specifically, the water filtered by the filter plate 23 flows down from the filter plate 23 and falls into the guide bucket 24 below. The funnel-shaped structure of the guide bucket 24 can concentrate the dispersed spray water and transport it to the hot water recovery tank 22 through the water outlet. The guide bucket 24 plays a role in guiding and converging the water flow, ensuring that all the filtered spray water can flow into the hot water recovery tank 22, and avoiding the spray water from flowing randomly in the spray tower 2, causing waste or affecting the normal operation of other equipment.

[0037] Please see Figure 1 In this embodiment, the primary waste heat recovery unit 11 is equipped with a dust filter 114, which is disposed on both sides of the primary heat exchange unit and is concave in shape. A dust filter is a mesh component with dust filtration function. In this embodiment, two dust filters are provided, installed on both sides of the primary heat exchange unit respectively, for dust removal from the high-temperature flue gas. Specifically, when the high-temperature flue gas enters the primary waste heat recovery unit 11 through the inlet pipe 111, it first passes through the dust filter 114 on one side of the primary heat exchange unit. The dust filter 114 can block most of the dust in the flue gas, preventing the dust from directly contacting the spiral heat exchange tube 112. Because the dust filter 114 is concave, the contact area with the flue gas is increased, allowing for the filtration of more dust. After heat exchange in the primary heat exchange unit, the flue gas, before being discharged from the primary waste heat recovery unit 11 through the connecting pipe 113, passes through the dust filter 114 on the other side of the primary heat exchange unit for further filtration, further removing dust from the flue gas. The dust filter 114 is set on both sides of the primary heat exchange unit, which can effectively block dust in the flue gas, prevent dust from adhering to the surface of the spiral heat exchange tube 112, prevent the heat exchange tube from being contaminated and affecting the heat exchange efficiency, and ensure the stable effect of waste heat recovery of the spiral heat exchange tube 112.

[0038] Working Principle: High-temperature flue gas from the kiln enters the primary waste heat recovery unit 11 through the flue gas inlet pipe 111. After some dust is filtered by the dust filter screen 114, it comes into contact with the spiral heat exchange tube 112. Low-temperature water from the low-temperature water inlet pipe 3 enters the spiral heat exchange tube 112, where it undergoes a primary heat exchange with the high-temperature flue gas. After absorbing heat, it is discharged from the high-temperature water outlet pipe 4 for subsequent use. The regulating valve 31 can adjust the flow rate of the low-temperature water entering the spiral heat exchange tube 112 according to the flue gas temperature to ensure the heat exchange effect. The flue gas after the primary heat exchange enters the S-shaped heat exchange tube 121 of the secondary waste heat recovery unit 12 through the connecting pipe 113. At the same time, the low-temperature water from the low-temperature water inlet pipe 3 enters the secondary waste heat recovery unit 12 through the water inlet pipe 122, where it undergoes a secondary heat exchange with the flue gas in the S-shaped heat exchange tube 121 to further recover waste heat. The water after heat exchange is discharged from the water outlet pipe 123. The flue gas, after undergoing secondary heat exchange, enters the spray tower 2 through the flue gas outlet pipe 124. The spray heads 212 spray the flue gas to remove residual dust and impurities and recover the remaining heat. The sprayed water falls onto the filter plate 23, and after filtration, flows into the hot water recovery tank 22 through the guide bucket 24. When the water temperature in the hot water recovery tank 22 reaches the expected temperature, the circulating pump extracts the hot water from the hot water recovery tank 22 for use.

[0039] The above description is only a part of the embodiments of this utility model, and does not limit the scope of protection of this utility model. Any equivalent device or equivalent process transformation made based on the content of this utility model specification and drawings, or direct or indirect application in other related technical fields, are similarly included in the patent protection scope of this utility model.

Claims

1. A waste heat recovery device for flue gas from a sodium silicate kiln, characterized in that, include: A waste heat recovery assembly includes a primary waste heat recovery unit and a secondary waste heat recovery unit. The primary waste heat recovery unit has a flue gas inlet pipe on one side and multiple primary heat exchange units inside. The other side of the primary waste heat recovery unit has a connecting pipe. The secondary waste heat recovery unit has a secondary heat exchange unit inside and is connected to the connecting pipe. The bottom of the secondary waste heat recovery unit has a water inlet pipe and the top has a water outlet pipe. The side of the secondary waste heat recovery unit away from the connecting pipe has a flue gas outlet pipe. A spray tower is connected to the secondary waste heat recovery unit through the flue pipe. The spray tower is equipped with a spray assembly and a hot water recovery tank. The hot water recovery tank is located below the spray assembly and is connected to the spray assembly.

2. The waste heat recovery device for sodium silicate kiln flue gas according to claim 1, characterized in that, The primary heat exchange unit is a spiral heat exchange tube. The inlets of the spiral heat exchange tubes extend out of the bottom wall of the primary waste heat recovery unit and are connected to the low-temperature inlet pipe. The outlets of the spiral heat exchange tubes extend out of the top wall of the primary waste heat recovery unit and are connected to the high-temperature outlet pipe.

3. The waste heat recovery device for sodium silicate kiln flue gas according to claim 2, characterized in that, The secondary heat exchange unit is an S-shaped heat exchange tube, and the two ends of the S-shaped heat exchange tube are respectively connected to the connecting pipe and the flue gas outlet pipe. The water inlet pipe of the secondary waste heat recovery unit is connected to the low-temperature water inlet pipe.

4. The waste heat recovery device for sodium silicate kiln flue gas according to claim 2, characterized in that, The low-temperature water inlet pipe is equipped with a regulating valve, which is used to regulate the amount of low-temperature water flowing into the spiral heat exchanger tube.

5. The waste heat recovery device for sodium silicate kiln flue gas according to claim 2, characterized in that, The spray assembly includes a spray pipe and multiple spray heads, all of which are distributed at the lower end of the spray pipe and are connected to the spray pipe.

6. The waste heat recovery device for sodium silicate kiln flue gas according to claim 5, characterized in that, A circulating water pump is connected to one side of the hot water recovery tank, and the circulating water pump is connected to the low-temperature water inlet pipe and the spray pipe.

7. The waste heat recovery device for sodium silicate kiln flue gas according to claim 1, characterized in that, The spray tower is equipped with a filter plate, which is located between the spray assembly and the hot water recovery tank. There are multiple filter plates, and all of them are inclined.

8. The waste heat recovery device for sodium silicate kiln flue gas according to claim 7, characterized in that, A diversion bucket is also provided below the filter plate, and the outlet end of the diversion bucket is connected to the hot water recovery tank.

9. A waste heat recovery device for sodium silicate kiln flue gas according to claim 1, characterized in that, The primary waste heat recovery unit is equipped with a dust filter screen, which is located on both sides of the primary heat exchange unit and is concave in shape.

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