A system and method for utilizing waste heat from a gypsum board drying machine

Abstract

The application discloses a kind of gypsum board drying machine's waste heat utilization system, including heat exchange device, spiral feeder and waste heat pipeline;Heat exchange device is installed in gypsum board drying section, can condense and recover the heat in waste heat exhaust gas;Spiral feeder is installed in gypsum powder feeding section, and spiral feeder has cylinder, and spiral cavity is arranged in cylinder;Waste heat pipeline is connected to heat exchange device and spiral feeder, and forms closed circulation passage;And a kind of gypsum board drying machine's waste heat utilization method.The application connects heat exchange device and spiral feeder by waste heat pipeline, forms closed circulation pipeline, and the refrigerant after heat absorption in heat exchange device is pumped to spiral cavity by heat pump to heat cylinder, to dry gypsum powder material, and the refrigerant after heat release is pumped back to heat exchange device by heat pump to heat absorption, to continuously circulate and dry gypsum powder material, realize the recycling of waste heat in waste heat exhaust gas, avoid the interference of steam and particulate matter in waste heat exhaust gas to waste heat recovery.

Description

Technical Field

[0001] This invention relates to the field of gypsum board production technology, specifically to a waste heat utilization system and method for a gypsum board dryer. Background Technology

[0002] After gypsum board is produced and formed, it needs to be sent into a gypsum board dryer for drying. During the drying process, waste heat gas is generated. If the waste heat gas is directly discharged, a lot of heat energy will be wasted. Therefore, the heat energy of the waste heat gas is often recovered and utilized in the production process.

[0003] Existing waste heat utilization methods typically involve adding heating pipes inside the feed hopper, and then sending waste heat gas through pipes and an induced draft fan into the heating pipes to heat the feed space, thereby pre-drying the gypsum powder. While existing methods of directly heating steel pipes with waste heat gas to dry gypsum powder can achieve preheating, the waste heat gas contains a large amount of steam and dust. During pipeline transport, water vapor condensation may occur, potentially leading to significant condensation over prolonged transport. Failure to drain this condensate promptly will affect heat transfer efficiency, resulting in heat loss. Furthermore, particulate matter in the waste heat gas may adhere to the inner wall of the heating pipes, further reducing heat release efficiency.

[0004] Therefore, the existing method of using waste heat and exhaust gas to directly heat steel pipes to dry gypsum powder has problems such as low waste heat utilization efficiency and incomplete waste heat utilization because condensate is difficult to drain in time and particulate matter easily adheres to the inner wall of the heating pipe. Summary of the Invention

[0005] The purpose of this invention is to provide a waste heat utilization system for a gypsum board dryer, so as to solve the technical problems in the prior art where condensate is difficult to be discharged in time and particulate matter is easy to adhere to the inner wall of the heating tube, resulting in low waste heat utilization efficiency and incomplete waste heat utilization.

[0006] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution:

[0007] A waste heat recovery system for a gypsum board dryer includes:

[0008] A heat exchange device is installed in the gypsum board drying section of the gypsum board production line. The heat exchange device is connected to the exhaust port of the drying equipment to absorb the heat of the high-temperature steam discharged from the exhaust port through the refrigerant inside it.

[0009] A screw feeder is installed in the gypsum powder feeding section of a gypsum board production line. The screw feeder includes a cylinder, and a screw cavity is provided in the inner wall of the cylinder. The screw cavity extends along the axis of the cylinder and forms interfaces at the inlet and outlet of the cylinder.

[0010] The waste heat pipeline is installed between the gypsum board drying section and the gypsum powder feeding section of the gypsum board production line. The waste heat pipeline is connected to the two interfaces and the heat exchange device to form a closed circulation channel.

[0011] The waste heat pipeline includes a heat pump that drives the refrigerant to circulate within the circulation channel, transferring heat from the exhaust vent to the screw feeder to preheat the gypsum powder.

[0012] As a preferred embodiment of the present invention, the heat exchange device includes a condensation chamber, one end of which is provided with an air inlet connected to the exhaust port of the drying equipment, an exhaust pipe is provided on the side of the condensation chamber away from the air inlet, and a drain pipe is provided at the lower end of the side of the condensation chamber near the exhaust pipe.

[0013] The condensation chamber is provided with an inclined condensation pipe. The inclined lower end and inclined upper end of the condensation pipe are connected to the outside of the condensation chamber to form a heat exchange interface. The heat absorption end of the waste heat pipeline is connected to the two heat exchange interfaces.

[0014] The heat pump can deliver the refrigerant into the condenser coil from the heat exchange interface near the upper inclined end of the condenser coil for heat absorption, and after the refrigerant has absorbed heat, deliver the refrigerant into the waste heat pipeline from the heat exchange interface near the lower inclined end of the condenser coil.

[0015] As a preferred embodiment of the present invention, a blower is provided inside the air inlet, and an exhaust fan is provided at the outer end of the exhaust pipe;

[0016] The blower and the exhaust fan can form a directional airflow in the condensation chamber, attracting waste heat gas into the condensation chamber with negative pressure, and guiding the condensed waste gas out through the exhaust pipe.

[0017] As a preferred embodiment of the present invention, the heat exchange device is further provided with a secondary heat pump, one end of which is connected to two sets of heat absorption pipes, and the other end of which is provided with heat release pipes.

[0018] The two heat-absorbing pipes are respectively installed inside the exhaust pipe and the liquid discharge pipe;

[0019] The heat absorption pipe and the heat release pipe both contain refrigerant, and the secondary heat pump can drive the refrigerant to circulate between the heat absorption pipe and the heat release pipe to recover the waste heat from the condensed waste gas and condensate.

[0020] As a preferred embodiment of the present invention, a shaftless spiral blade is rotatably provided inside the cylinder along the axis of the cylinder, and an air jet rod is inserted into the axis of the shaftless spiral blade;

[0021] The jet rod has several protruding nozzles, the nozzle orifices of which are oriented toward the feeding direction of the shaftless spiral blade, and the interiors of the nozzles are interconnected to form an air delivery channel.

[0022] The shaftless spiral blade is equipped with several tilting plates. When the shaftless spiral blade feeds the material, the tilting plates can lift the gypsum powder, and at the same time, the air jet rod can send air into the cylinder through the nozzle to fully dry the gypsum powder.

[0023] In a preferred embodiment of the present invention, a hot air pipe is connected to one end of the jet rod near the feed inlet, and a hot air duct is provided at the end of the hot air pipe away from the jet rod.

[0024] The heat-releasing pipe is located inside the hot air duct, and a hot air blower is installed at the end of the hot air duct away from the hot air pipe. The hot air blower can blow air onto the heat-releasing pipe for heating, and blow the heated air through the hot air duct into the jet rod.

[0025] As a preferred embodiment of the present invention, a driving member is provided through the end of the cylinder near the feed port, and the shaftless spiral blade is fixedly disposed at one end of the driving member located inside the cylinder.

[0026] The drive unit is located on one side of the cylinder body and is connected to a drive source. The drive source can drive the shaftless spiral blade to perform spiral feeding through the drive unit.

[0027] In a preferred embodiment of the present invention, the driving component is hollow, and the jet rod is inserted into the shaft of the shaftless spiral blade through the central hole of the driving component, and the driving component and the jet rod are rotatably connected.

[0028] The cylinder has support rods located at the lower end near the discharge port and the lower outer end near the inlet port, and the two ends of the jet rod are fixed to the two support rods.

[0029] As a preferred embodiment of the present invention, a crushing gear is provided at the lower end of the feed inlet of the screw feeder, and a crushing motor is provided on the outside of the feed inlet. The crushing motor can drive the crushing gear to crush the wet and lumpy gypsum powder.

[0030] The screw feeder has an air outlet at the upper end of the side near the discharge port. A fan is installed inside the air outlet. The fan can blow air out of the cylinder to guide the dried humid gas inside the cylinder to be discharged.

[0031] The lower end of the air outlet is equipped with a dustproof mesh.

[0032] To address the aforementioned technical problems, the present invention further provides the following technical solution:

[0033] The waste heat utilization method based on the above-mentioned waste heat utilization system for gypsum board dryer is characterized by comprising the following steps:

[0034] Step 100: The waste heat gas generated by the gypsum board drying equipment enters the heat exchange device from the exhaust port to release heat and condense. The refrigerant absorbs heat in the heat exchange device and is sent into the waste heat pipeline through the heat pump.

[0035] Step 200: The heat pump pumps the refrigerant along the waste heat pipeline into the spiral cavity to heat the inner wall of the cylinder. Moist gypsum powder is put in from the feed port and dried inside the cylinder.

[0036] Step 300: The gypsum powder is conveyed to the calcining furnace by a screw feeder. After the refrigerant releases heat, it enters the waste heat pipeline through the interface near the discharge port. The heat pump then pumps the refrigerant back to the heat exchange device along the waste heat pipeline to absorb heat.

[0037] Compared with the prior art, the present invention has the following advantages:

[0038] This invention connects a heat exchange device to a screw feeder via a waste heat pipeline, forming a closed circulation pipeline. A heat pump pumps the refrigerant, which has absorbed heat in the heat exchange device, to the screw cavity to heat the cylinder and dry the gypsum powder. Then, the heat pump pumps the refrigerant, which has released heat, back to the heat exchange device to absorb heat, thus continuously circulating and drying the gypsum powder. This achieves the recovery and utilization of waste heat in the waste gas and avoids interference from steam and particulate matter in the waste gas on waste heat recovery. Attached Figure Description

[0039] To more clearly illustrate the embodiments of the present invention or the technical solutions in 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 merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0040] Figure 1 A schematic diagram of the waste heat utilization system of the gypsum board dryer provided in an embodiment of the present invention;

[0041] Figure 2This is a partial structural schematic diagram of the heat exchange device provided in an embodiment of the present invention;

[0042] Figure 3 This is a schematic diagram of a portion of the screw feeder structure provided in an embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of the jet rod structure provided in an embodiment of the present invention.

[0044] The labels in the diagram represent the following:

[0045] 1-Heat exchange device; 2-Screw feeder; 3-Waste heat pipeline;

[0046] 11-Condensation chamber; 12-Condensation coil; 13-Secondary heat pump; 21-Cylinder; 22-Spiral cavity; 23-Shaftless spiral blade; 24-Jet rod; 25-Hot air duct; 26-Drive component; 27-Support rod; 28-Scrap gear; 29-Air outlet; 31-Heat pump;

[0047] 111-Air inlet; 112-Exhaust pipe; 113-Drain pipe; 114-Blower; 115-Exhaust fan; 121-Heat exchange interface; 131-Heat absorption pipe; 132-Heat release pipe; 221-Interface; 231-Tilting plate; 241-Nozzle; 242-Air delivery channel; 251-Hot air duct; 252-Hot air blower. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] like Figures 1 to 4 As shown, the present invention provides a waste heat utilization system for a gypsum board dryer, comprising:

[0050] Heat exchange device 1 is installed in the gypsum board drying section of the gypsum board production line. Heat exchange device 1 is connected to the exhaust port of the drying equipment to absorb the heat of the high-temperature steam discharged from the exhaust port through the refrigerant inside it.

[0051] The screw feeder 2 is installed in the gypsum powder feeding section of the gypsum board production line. The screw feeder 2 includes a cylinder 21. A screw cavity 22 is provided in the inner wall of the cylinder 21. The screw cavity 22 extends along the axis of the cylinder 21 and forms an interface 221 at the inlet and outlet of the cylinder 21.

[0052] Waste heat pipeline 3 is installed between the gypsum board drying section and the gypsum powder feeding section of the gypsum board production line. Waste heat pipeline 3 is connected to two interfaces 221 and heat exchange device 1 to form a closed circulation channel.

[0053] Among them, the waste heat pipeline 3 has a heat pump 31, which drives the refrigerant to circulate in the circulation channel to transfer the heat from the exhaust port to the screw feeder 2 to preheat the gypsum powder.

[0054] In this embodiment, the waste heat pipeline 3 is connected to the heat exchange device 1 and the screw feeder 2 to form a closed circulation path. After the waste heat gas enters the heat exchange device 1, the heat of the waste heat gas is absorbed by the refrigerant in the heat exchange device 1. The heat-absorbing refrigerant is pumped to the screw cavity 22 along the waste heat pipeline 3 by the heat pump 31. The refrigerant releases heat in the screw cavity 22 to dry the gypsum powder in the cylinder 21. The heat-released refrigerant flows back from the screw cavity 22 to the waste heat pipeline 3, and is pumped back to the heat exchange device 1 by the heat pump 31 to absorb heat, thereby performing circulating heat exchange.

[0055] In this embodiment, the heat exchange device 1 and the screw feeder 2 are connected by the waste heat pipeline 3 to form a closed circulation path. The heat of the waste gas in the heat exchange device 1 is absorbed by the refrigerant, and then the heat-absorbing refrigerant is pumped into the screw cavity 22 by the heat pump 31. The refrigerant releases heat in the screw cavity 22 to raise the temperature inside the cylinder 21, so as to dry the damp gypsum powder. The heat-releasing refrigerant is pumped back into the heat exchange device 1 by the heat pump 31 to absorb heat for continuous drying, thus realizing the recovery and utilization of waste heat and avoiding the impact of steam and particles in the waste gas on the waste heat transportation.

[0056] The working principle of the heat pump 31, the waste heat pipeline 3 and the refrigerant is the same as that of the conventional heat pump 31. The heat pump 31 can compress the refrigerant in the low temperature and low pressure superheated steam state after absorbing heat into the high temperature and high pressure steam state, and deliver the refrigerant to the spiral cavity 22 to release heat and condense. Then, the liquid refrigerant expands into a gas-liquid mixture state and is delivered to the heat exchange device 1 to absorb heat and become a low temperature and low pressure superheated steam state.

[0057] In order to enable the waste heat gas to condense and release heat in the heat exchange device 1, the following preferred embodiments are proposed.

[0058] like Figure 2 As shown, the heat exchange device 1 includes a condensation chamber 11. One end of the condensation chamber 11 is provided with an air inlet 111, which is connected to the exhaust port of the drying equipment. An exhaust pipe 112 is provided on the side of the condensation chamber 11 away from the air inlet 111, and a drain pipe 113 is provided at the lower end of the side of the condensation chamber 11 near the exhaust pipe 112.

[0059] A condenser pipe 12 is inclinedly arranged inside the condenser chamber 11. The inclined lower end and inclined upper end of the condenser pipe 12 are connected to the outside of the condenser chamber 11 to form a heat exchange interface 121. The heat absorption end of the waste heat pipeline 3 is connected to the two heat exchange interfaces 121.

[0060] The heat pump 31 can send refrigerant into the condenser coil 12 from the heat exchange interface 121 near the upper inclined end of the condenser coil 12 for heat absorption, and after the refrigerant has absorbed heat, send the refrigerant into the waste heat pipeline 3 from the heat exchange interface 121 near the lower inclined end of the condenser coil 12.

[0061] Specifically, the waste heat exhaust gas enters the condensation chamber 11 through the air inlet 111 from the exhaust port of the drying equipment. The waste heat exhaust gas releases heat when passing through the condensation pipe 12, and the refrigerant in the condensation pipe 12 absorbs heat. The steam in the waste heat exhaust gas condenses and drips downwards, or flows down along the inclined condensation pipe 12, and finally flows out from the drain pipe 113 at the bottom of the condensation chamber 11. The condensed gas then enters the exhaust pipe 112.

[0062] To facilitate the collection of waste heat and exhaust gas generated by the drying equipment, the following preferred embodiments are proposed.

[0063] like Figure 2 As shown, a blower 114 is installed inside the air inlet 111, and an exhaust fan 115 is installed at the outer end of the exhaust pipe 112. The exhaust fan 115 draws the waste heat gas into the condensation chamber 11 with negative pressure and guides the condensed waste gas to be discharged through the exhaust pipe 112.

[0064] Specifically, the blower 114 can collect waste heat and exhaust gas under negative pressure, and the exhaust fan 115 can guide the condensed gas out of the condensation chamber 11.

[0065] Typically, after the waste heat exhaust gas is condensed, the heat of the condensate and the gas is usually between 40 and 60 degrees Celsius. In order to further recover the waste heat, the following preferred embodiments are proposed.

[0066] like Figure 2 As shown, the heat exchange device 1 is also equipped with a secondary heat pump 13. One end of the secondary heat pump 13 is connected to two sets of heat absorption pipes 131, and the other end of the secondary heat pump 13 is equipped with heat release pipes 132.

[0067] Two heat absorption pipes 131 are respectively installed in the exhaust pipe 112 and the liquid drain pipe 113;

[0068] The heat absorption pipe 131 and the heat release pipe 132 also contain refrigerant. The secondary heat pump 13 can drive the refrigerant to circulate between the heat absorption pipe 131 and the heat release pipe 132 to recover the waste heat from the condensed exhaust gas and condensate.

[0069] Specifically, the two sets of heat absorption tubes 131 can perform secondary heat absorption on the condensed gas and condensate.

[0070] To ensure thorough drying of the gypsum powder, the following preferred embodiments are proposed.

[0071] like Figure 3 and 4 As shown, a shaftless spiral blade 23 is rotatably arranged inside the cylinder 21 along the axis of the cylinder 21, and an air jet rod 24 is inserted into the axis of the shaftless spiral blade 23.

[0072] The jet rod 24 has several protruding nozzles 241. The nozzles 241 are oriented toward the feeding direction of the shaftless spiral blade 23. The interior of the nozzles 241 is connected to form an air delivery channel 242.

[0073] The shaftless spiral blade 23 is equipped with several tilting plates 231. When the shaftless spiral blade 23 feeds material, the tilting plates 231 can lift the gypsum powder, and at the same time the air jet rod 24 can send air into the cylinder 21 through the nozzle 241 to fully dry the gypsum powder.

[0074] Specifically, while the shaftless spiral blade 23 is conveying gypsum powder, the tipping plate 231 can simultaneously lift the gypsum powder and then send air in the conveying direction of the gypsum powder through the air jet rod 24, so that the gypsum powder can be fully dried.

[0075] Sending hot air to gypsum powder can improve the drying effect of gypsum powder. Therefore, the following preferred embodiments are proposed.

[0076] like Figure 3 As shown, a hot air pipe 25 is connected to one end of the jet rod 24 near the feed inlet, and a hot air duct 251 is provided at the end of the hot air pipe 25 away from the jet rod 24.

[0077] The heat release pipe 132 is coiled inside the hot air duct 251. A hot air blower 252 is installed through the end of the hot air duct 251 away from the hot air pipe 25. The hot air blower 252 can blow air onto the heat release pipe 132 for heating and blow the heated air into the jet rod 24 through the hot air pipe 25.

[0078] Specifically, the waste heat absorbed by the heat absorption pipe 131 heats the heat release pipe 132, and then the hot air blown by the hot air blower 251 heats the heat release pipe 132 and is delivered to the jet bar 24 through the hot air pipe to dry the gypsum powder.

[0079] To achieve spiral feeding of the shaftless spiral blade 23, the following preferred embodiments are proposed.

[0080] like Figure 3As shown, a drive unit 26 is provided through the end of the cylinder 21 near the feed inlet, and a shaftless spiral blade 23 is fixedly installed at one end of the drive unit 26 located inside the cylinder 21.

[0081] Among them, the drive component 26 is connected to a drive source on one side outside the cylinder 21. The drive source can drive the shaftless spiral blade 23 to perform spiral feeding through the drive component 26.

[0082] The drive component 26 is hollow, and the jet rod 24 is inserted into the shaft of the shaftless spiral blade 23 through the central hole of the drive component 26. The drive component 26 and the jet rod 24 are rotatably connected.

[0083] Support rods 27 are provided at the lower end of the cylinder 21 near the discharge port and at the lower outer end of the cylinder 21 near the inlet port. The two ends of the jet rod 24 are fixed to the two support rods 27.

[0084] Specifically, the jet rod 24 passes through the drive member 26 and is fixed to the two support rods 27. The drive source can drive the shaftless spiral blade 23 to perform spiral feeding through the drive member 26.

[0085] Damp gypsum powder may clump together. To ensure that the gypsum powder is fully dried, the following preferred embodiments are proposed.

[0086] like Figure 3 As shown, a crushing gear 28 is provided at the lower end of the feed inlet of the screw feeder 2, and a crushing motor is provided on the outside of the feed inlet. The crushing motor can drive the crushing gear 28 to crush the wet and lumpy gypsum powder.

[0087] The screw feeder 2 has an air outlet 29 at the upper end of the side near the discharge port. A fan is installed inside the air outlet 29. The fan can blow air out of the cylinder 21 to guide the dried humid gas inside the cylinder 21 to be discharged.

[0088] The lower end of the air outlet 29 is equipped with a dustproof mesh.

[0089] Specifically, the crushing gear 28 can break up clumps of gypsum powder to increase the surface area of ​​the gypsum powder exposed to heat.

[0090] The fan can guide the dried, humid gas inside the cylinder 21 to be discharged.

[0091] Based on the above, the following method for utilizing the waste heat of a gypsum board dryer is provided, including the following steps:

[0092] Step 100: The waste heat gas generated by the gypsum board drying equipment enters the heat exchange device from the exhaust port to release heat and condense. The refrigerant absorbs heat in the heat exchange device and is sent into the waste heat pipeline through the heat pump.

[0093] Step 200: The heat pump pumps the refrigerant along the waste heat pipeline into the spiral cavity to heat the inner wall of the cylinder. Moist gypsum powder is put in from the feed port and dried inside the cylinder.

[0094] Step 300: The gypsum powder is conveyed to the calcining furnace by a screw feeder. After the refrigerant releases heat, it enters the waste heat pipeline through the interface near the discharge port. The heat pump then pumps the refrigerant back to the heat exchange device along the waste heat pipeline to absorb heat.

[0095] In this embodiment, the waste heat is mainly collected by the negative pressure of the blower 114 to the condensation chamber 11. At this time, the refrigerant in the condensation pipe 12 absorbs heat, causing the waste heat to condense and produce gas and condensate. The gas enters the exhaust pipe 112 through the exhaust fan 115, and the condensate flows downward into the drain pipe 113. At the same time, the waste heat in the gas and condensate is absorbed through the two heat absorption pipes 131.

[0096] Then, the heat pump 31 pumps the heat-absorbing condensate into the spiral cavity 22 to heat the cylinder 21. At the same time, the heat release pipe 132 releases heat in the hot air duct 25. The hot air is generated by the hot air blower 252 and delivered to the jet bar 24. At this time, the gypsum powder is fed in from the feed port, crushed by the crushing gear 28, and then conveyed by the shaftless spiral blade 23. During the conveying process, it is dried by the hot air sprayed from the high-temperature cylinder 21 and the jet bar 24.

[0097] Then, the dried gypsum powder is conveyed to the calcining furnace by the shaftless spiral blade 23. The humid gas in the cylinder 21 is discharged by the fan 291. The heat pump 31 pumps the condenser back into the condenser pipe 12 to absorb heat, so as to continuously circulate and dry the gypsum powder.

[0098] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

Claims

1. A waste heat utilization system for a gypsum board dryer, characterized in that, include: A heat exchange device (1) is installed in the gypsum board drying section of the gypsum board production line. The heat exchange device (1) is connected to the exhaust port of the drying equipment to absorb the heat of the high-temperature steam discharged from the exhaust port through the refrigerant inside it. A screw feeder (2) is installed in the gypsum powder feeding section of the gypsum board production line. The screw feeder (2) includes a cylinder (21). A screw cavity (22) is provided in the inner wall of the cylinder (21). The screw cavity (22) extends along the axis of the cylinder (21) and forms an interface (221) at the inlet and outlet of the cylinder (21). Waste heat pipeline (3) is set between the gypsum board drying section and the gypsum powder feeding section of the gypsum board production line. The waste heat pipeline (3) connects the two interfaces (221) and the heat exchange device (1) to form a closed circulation channel. The waste heat pipeline (3) has a heat pump (31), which drives the refrigerant to circulate in the circulation channel to transfer the heat from the exhaust port to the screw feeder (2) to preheat the gypsum powder. The heat exchange device (1) includes a condensation chamber (11), one end of which is provided with an air inlet (111), which is connected to the exhaust port of the drying equipment. An exhaust pipe (112) is provided on the side of the condensation chamber (11) away from the air inlet (111), and a drain pipe (113) is provided at the lower end of the side of the condensation chamber (11) near the exhaust pipe (112). The condensing chamber (11) is provided with an inclined condensing pipe (12). The inclined lower end and inclined upper end of the condensing pipe (12) are connected to the outside of the condensing chamber (11) to form a heat exchange interface (121). The heat absorption end of the waste heat pipeline (3) is connected to the two heat exchange interfaces (121). The heat pump (31) can send the refrigerant from the heat exchange interface (121) near the upper inclined end of the condenser pipe (12) into the condenser pipe (12) to absorb heat, and after the refrigerant has absorbed heat, send the refrigerant from the heat exchange interface (121) near the lower inclined end of the condenser pipe (12) into the waste heat pipeline (3); The heat exchange device (1) is also provided with a secondary heat pump (13), one end of which is connected to two sets of heat absorption pipes (131), and the other end of which is provided with heat release pipes (132). The two heat absorption pipes (131) are respectively installed in the exhaust pipe (112) and the liquid discharge pipe (113); The heat absorption pipe (131) and the heat release pipe (132) both contain refrigerant. The secondary heat pump (13) can drive the refrigerant to circulate between the heat absorption pipe (131) and the heat release pipe (132) to recover the residual heat in the condensed waste gas and condensate.

2. The waste heat utilization system of a gypsum board dryer according to claim 1, characterized in that, A blower (114) is provided inside the air inlet (111), and an exhaust fan (115) is provided at the outer end of the exhaust pipe (112). The blower (114) and the exhaust fan (115) can form a directional airflow in the condensation chamber (11) to attract waste heat gas into the condensation chamber (11) with negative pressure, and guide the condensed waste gas to be discharged through the exhaust pipe (112).

3. The waste heat utilization system of a gypsum board dryer according to claim 1, characterized in that, Inside the cylinder (21), a shaftless spiral blade (23) is rotatably arranged along the axis of the cylinder (21), and an air jet rod (24) is inserted into the axis of the shaftless spiral blade (23). The jet rod (24) has several protruding nozzles (241), the nozzles (241) are arranged facing the feeding direction of the shaftless spiral blade (23), and the interior of the nozzles (241) is connected to form an air delivery channel (242). The shaftless spiral blade (23) is provided with several turning plates (231). When the shaftless spiral blade (23) performs spiral feeding, the turning plates (231) can lift the gypsum powder, and at the same time, the air jet rod (24) can send air into the cylinder (21) through the nozzle (241) to fully dry the gypsum powder.

4. The waste heat utilization system of a gypsum board dryer according to claim 3, characterized in that, A hot air pipe (25) is connected to one end of the jet rod (24) near the feed inlet, and a hot air tube (251) is provided at the end of the hot air pipe (25) away from the jet rod (24). The heat-releasing pipe (132) is coiled inside the hot air duct (251). A hot air blower (252) is installed through the end of the hot air duct (251) away from the hot air pipe (25). The hot air blower (252) can blow air onto the heat-releasing pipe (132) for heating and blow the heated air through the hot air pipe (25) into the jet rod (24).

5. The waste heat utilization system of a gypsum board dryer according to claim 3, characterized in that, A drive unit (26) is provided through the end of the cylinder (21) near the feed inlet, and the shaftless spiral blade (23) is fixedly provided at one end of the drive unit (26) located inside the cylinder (21); The drive unit (26) is connected to a drive source on one side outside the cylinder (21). The drive source can drive the shaftless spiral blade (23) to perform spiral feeding through the drive unit (26).

6. The waste heat utilization system of a gypsum board dryer according to claim 5, characterized in that, The drive component (26) is hollow, and the jet rod (24) is inserted into the shaft of the shaftless spiral blade (23) through the central hole of the drive component (26). The drive component (26) and the jet rod (24) are rotatably connected. Among them, the lower end of the cylinder (21) near the discharge port and the lower outer end of the cylinder (21) near the inlet port are provided with support rods (27), and the two ends of the jet rod (24) are fixed on the two support rods (27).

7. The waste heat utilization system of a gypsum board dryer according to claim 1, characterized in that, The screw feeder (2) is provided with a crushing gear (28) at the lower end of the feed inlet and a crushing motor is provided on the outside of the feed inlet. The crushing motor can drive the crushing gear (28) to crush the wet lumps of gypsum powder. The spiral feeder (2) has an air outlet (29) at the upper end of the side near the discharge port. A fan is installed inside the air outlet (29). The fan can send air to the outside of the cylinder (21) to guide the dried humid gas inside the cylinder (21) to be discharged. The lower end of the air outlet (29) is provided with a dustproof mesh.

8. A method for utilizing the waste heat of a gypsum board dryer according to any one of claims 1-7, characterized in that, Includes the following steps: Step 100: The waste heat gas generated by the gypsum board drying equipment enters the heat exchange device from the exhaust port to release heat and condense. The refrigerant absorbs heat in the heat exchange device and is sent into the waste heat pipeline through the heat pump. Step 200: The heat pump pumps the refrigerant along the waste heat pipeline into the spiral cavity to heat the inner wall of the cylinder. The moist gypsum powder is put in from the feed port and dried inside the cylinder. Step 300: The gypsum powder is conveyed to the calcining furnace by a screw feeder. After the refrigerant releases heat, it enters the waste heat pipeline through the interface near the discharge port. The heat pump then pumps the refrigerant back to the heat exchange device along the waste heat pipeline to absorb heat.

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