A direct-fired regeneration drying system and its use method

Abstract

The invention relates to the technical field of dryers, and discloses a direct-fired regenerative drying system, comprising a rotary dryer, the rotary dryer comprising a rotor, on which drying materials for drying airflow are arranged, the rotary dryer comprising a drying zone located at the bottom and a regeneration zone located at the top, the drying materials are switched between the drying zone and the regeneration zone by the rotation of the rotor, the air inlet end of the drying zone is connected to a surface cooler, the air outlet end of the drying zone is connected to a reheater and a first fan in sequence, the air inlet end of the regeneration zone is connected to a burner, the air outlet end of the regeneration zone is connected to a waste heat recovery device and a second fan in sequence, the liquid outlet end of the waste heat recovery device is connected to the liquid inlet end of the reheater, and the liquid outlet end of the reheater is connected to the liquid inlet end of the waste heat recovery device; a method for using the direct-fired regenerative drying system is also disclosed; the use of the invention has the advantages of low operating cost, energy saving and environmental protection, and continuous and stable operation.

Description

Technical Field

[0001] The present invention relates to the technical field of drying systems, and in particular to a direct-fired regeneration drying system and a use method thereof. Background Art

[0002] Precision constant temperature and humidity air conditioners are widely used in biotechnology, electronics, precision processing, food and medicine and other industries. In order to ensure that the temperature, humidity, dust content and other indicators of precision constant temperature and humidity air conditioners meet the process requirements, the air treatment is quite complicated and the energy consumption is particularly high.

[0003] Among them, the characteristics of precision air conditioning are: first, the relative humidity of the air supply is low, generally required to be less than 25%, and the dehumidification requirements are particularly high, and a rotary dehumidifier must be used to meet the requirements; second, the air conditioning room temperature control accuracy is high, usually within ±0.5℃, and the air supply temperature difference cannot be high, so the air supply must be reheated before entering the room. However, in the existing technology, electric heating technology is usually used to heat the fresh air, using power as a heat source, which has high operating costs, is not energy-saving and environmentally friendly, and has the problem of increasing power consumption. Summary of the invention

[0004] The problem to be solved by the present invention is to provide a direct-fired regeneration drying system and a method for using the same, which has low operating costs, is energy-saving and environmentally friendly, and has continuous and stable operation.

[0005] In order to solve the above technical problems, the present invention provides a direct-fired regenerative drying system and a method for using the same, including a rotary dryer, the rotary dryer including a rotary wheel, the rotary wheel being provided with a drying material for drying the airflow, the rotary dryer including a drying zone located at the bottom and a regeneration zone located at the top, the drying material being switched between the drying zone and the regeneration zone by the rotation of the rotary wheel, the air inlet end of the drying zone being connected to a surface cooler, the air outlet end of the drying zone being connected to a reheater and a first fan in sequence, the air inlet end of the regeneration zone being connected to a burner, the air outlet end of the regeneration zone being connected to a waste heat recovery device and a second fan in sequence, the liquid outlet end of the waste heat recovery device being connected to the liquid inlet end of the reheater, and the liquid outlet end of the reheater being connected to the liquid inlet end of the waste heat recovery device.

[0006] As a preferred solution of the direct-fired regeneration drying system of the present invention, the air inlet end of the surface cooler is connected to a first filter, and the air outlet end of the first fan is connected to a second filter.

[0007] As a preferred solution of the direct-fired regeneration drying system of the present invention, a third filter is connected between the burner and the regeneration zone.

[0008] As a preferred embodiment of the direct-fired regeneration drying system of the present invention, the liquid outlet end of the waste heat recovery device is connected to the liquid inlet end of the reheater via a first liquid infusion pipe, the liquid outlet end of the reheater is connected to the liquid inlet end of the waste heat recovery device via a second liquid infusion pipe, and a second solenoid valve, a water pump and a flow limiting valve are sequentially provided on the first liquid infusion pipe along the water flow direction.

[0009] As a preferred embodiment of the direct-fired regeneration drying system of the present invention, it also includes a liquid storage tank, the liquid inlet end of the liquid storage tank is connected with the first liquid infusion pipe through a third liquid infusion pipe, and the liquid inlet end of the third liquid infusion pipe is located between the liquid outlet end of the waste heat recovery device and the second solenoid valve, and a third solenoid valve is provided on the third liquid infusion pipe, the liquid outlet end of the liquid storage tank is connected with the first liquid infusion pipe through a fourth liquid infusion pipe, and the liquid outlet end of the fourth liquid infusion pipe is located between the second solenoid valve and the water pump, and a fourth solenoid valve is provided on the fourth liquid infusion pipe.

[0010] As a preferred embodiment of the direct-fired regeneration drying system of the present invention, the burner includes an igniter and a gas nozzle, the gas nozzle is connected to the gas supply equipment through a gas channel, a first solenoid valve is provided on the gas channel, and the igniter is arranged at the nozzle of the gas nozzle.

[0011] As a preferred embodiment of the direct-fired regeneration drying system of the present invention, the drying material is a honeycomb-shaped paper fiber material, and lithium bromide is evenly arranged on the paper fiber material.

[0012] As a preferred solution of the direct-fired regeneration drying system of the present invention, the liquid storage tank contains antifreeze liquid.

[0013] Another aspect of the present invention provides a method for using a direct-fired regeneration drying system, comprising the following steps:

[0014] Start the first fan, the fresh air enters the surface cooler for cooling, the clean air after cooling enters the drying area of ​​the dryer for drying and dehumidification, the dry air after drying and dehumidification enters the reheater for heating, and the dry air after heating is discharged;

[0015] Start the second fan, and the fresh air is heated to a predetermined temperature by the burner, and then enters the regeneration area of ​​the dryer, and evaporates the moisture of the drying material in the regeneration area. The hot air after moisture absorption enters the waste heat recovery device, and exchanges heat with the liquid in the waste heat recovery device. After the heat exchange is completed, the warm air is discharged;

[0016] After the liquid in the waste heat recovery device completes heat exchange, it flows into the reheater and heats the dry air after drying and dehumidification. After the liquid in the reheater completes heating the dry air, it flows back to the waste heat recovery device to form a cycle.

[0017] As a preferred embodiment of the method for using the direct-fired regeneration drying system of the present invention, the liquid outlet of the waste heat recovery device is connected to the liquid inlet of the reheater via a first liquid infusion pipe, the liquid outlet of the reheater is connected to the liquid inlet of the waste heat recovery device via a second liquid infusion pipe, and a second solenoid valve, a water pump and a flow limiting valve are sequentially arranged on the first liquid infusion pipe along the water flow direction;

[0018] The direct-fired regeneration drying system further includes a liquid storage tank, the liquid inlet end of the liquid storage tank is connected to the first liquid infusion pipe through a third liquid infusion pipe, and the liquid inlet end of the third liquid infusion pipe is located between the liquid outlet end of the waste heat recovery device and the second solenoid valve, a third solenoid valve is provided on the third liquid infusion pipe, the liquid outlet end of the liquid storage tank is connected to the first liquid infusion pipe through a fourth liquid infusion pipe, and the liquid outlet end of the fourth liquid infusion pipe is located between the second solenoid valve and the water pump, and a fourth solenoid valve is provided on the fourth liquid infusion pipe;

[0019] When working, the following steps are included:

[0020] Step 1: close the second solenoid valve, open the third solenoid valve, the fourth solenoid valve and the flow limiting valve, the liquid in the liquid storage tank enters the water pump through the fourth infusion pipe, enters the reheater through the first infusion pipe through the flow limiting valve, and heats the dry air after dehumidification. After the liquid is heated in the reheater, it enters the waste heat recovery device through the second infusion pipe and exchanges heat with the hot air after moisture absorption. After the liquid completes heat exchange in the waste heat recovery device, it flows back to the liquid storage tank through the first infusion pipe and the third infusion pipe to form a cycle;

[0021] Step 2: After the heat exchange between the reheater and the waste heat recovery device is stable, open the second solenoid valve, close the third solenoid valve and the fourth solenoid valve. After the liquid completes the heat exchange in the waste heat recovery device, it enters the water pump through the first infusion pipe, and enters the reheater through the limiting valve to heat the dry air after dehumidification. After the liquid is heated in the reheater, it flows back to the waste heat recovery device through the second infusion pipe to form a cycle.

[0022] Compared with the prior art, the direct-fired regeneration drying system and the method of using the same according to the present invention have the following beneficial effects:

[0023] The drying material in the rotary dryer is switched between the drying area and the regeneration area by the rotation of the rotary wheel. When the drying material is in the drying area, the drying material dries the fresh air. When the drying material is in the regeneration area, the moisture on the drying material is heated and evaporated by the hot air and taken out, so that the drying material recovers the dehumidification function. The hot air after heating exchanges heat with the liquid in the waste heat recovery device, providing heat for the liquid in the waste heat recovery device. After the heat exchange is completed, the liquid in the waste heat recovery device flows into the reheater and heats the dried drying air. After the heat exchange is completed, the liquid in the reheater flows back to the waste heat recovery device. A cycle is formed, so that the liquid circulates and exchanges heat between the waste heat recovery device and the reheater, which saves water and ensures that the heat exchange process is stable and continuous; the hot air can not only dehumidify the drying material, but also indirectly heat the drying air. Compared with the use of power as a heat source in the prior art, the present invention uses the heat source of hot air as a heat source, which is green and environmentally friendly, saves energy, and can also solve the problem of increasing power consumption, reducing the production cost and operating cost. Through calculation, it can be seen that the operating cost of using the heat source of hot air as a heat source in the present invention is about 30% of the operating cost of using power as a heat source in the prior art. It can be seen that the operating cost of the present invention is low, energy-saving and environmentally friendly, and the operation is continuous and stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings of the embodiment are briefly introduced below.

[0025] Figure 1 This is a flow chart of a direct-fired regeneration drying system provided by the present invention;

[0026] Figure 2 It is a schematic diagram of the connection between the waste heat recovery device and the reheater;

[0027] Figure 3 It is a schematic diagram of the structure of the burner. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like used in the present invention to indicate the orientation or position relationship is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0030] See also Figure 1 As shown, one aspect of the present invention provides a preferred embodiment of a direct-fired regenerative drying system, a direct-fired regenerative drying system, comprising a rotary dryer 1, the rotary dryer 1 comprising a rotor 2, the rotor 2 being provided with a drying material for drying airflow, the rotary dryer 1 comprising a drying zone 3 located at the bottom and a regeneration zone 4 located at the top, the drying material being switched between the drying zone 3 and the regeneration zone 4 by the rotation of the rotor 2, the air inlet end of the drying zone 3 being connected with a surface cooler 5, the air outlet end of the drying zone 3 being connected with a reheater 6 and a first fan 7 in sequence, the air inlet end of the regeneration zone 4 being connected with a burner 8, the air outlet end of the regeneration zone 4 being connected with a waste heat recovery device 9 and a second fan 10 in sequence, the liquid outlet end of the waste heat recovery device 9 being connected with the liquid inlet end of the reheater 6, and the liquid outlet end of the reheater 6 being connected with the liquid inlet end of the waste heat recovery device 9. Specifically, the waste heat recovery device 9 is a surface coil heat exchanger.

[0031] Therefore, the drying material in the rotary dryer 1 is switched between the drying zone 3 and the regeneration zone 4 by the rotation of the rotary wheel 2. When the drying material is in the drying zone 3, the drying material dries the fresh air. When the drying material is in the regeneration zone 4, the moisture on the drying material is heated and evaporated by the hot air and taken out, so that the drying material recovers the dehumidification function. The hot air after heating exchanges heat with the liquid in the waste heat recovery device 9, and provides heat for the liquid in the waste heat recovery device 9. After the heat exchange of the liquid in the waste heat recovery device 9 is completed, it flows into the reheater 6 and heats the drying air after drying. After the heat exchange of the liquid in the reheater 6 is completed, it flows into the reheater 6. The waste heat recovery device 9 forms a cycle, so that the liquid circulates and exchanges heat between the waste heat recovery device 9 and the reheater 6, which saves water and ensures that the heat exchange process is stable and continuous; the hot air can not only dehumidify the drying material, but also indirectly heat the drying air. Compared with the use of power as a heat source in the prior art, the present invention uses the heat source of hot air as a heat source, which is green and environmentally friendly, saves energy, and can also solve the problem of increasing power consumption, reducing the production cost and operating cost. Through calculation, it can be seen that the operating cost of using the heat source of hot air as a heat source in the present invention is about 30% of the operating cost of using power as a heat source in the prior art. It can be seen that the operating cost of the present invention is low, energy-saving and environmentally friendly, and the operation is continuous and stable.

[0032] Exemplarily, the air inlet end of the surface cooler 5 is connected to a first filter 11, and the air outlet end of the first fan 7 is connected to a second filter 12. The first filter 11 can filter the fresh air entering the direct-fired regeneration drying system, purify the air, and prevent particulate impurities in the air from damaging the dryer; the second filter 12 can filter the dry air discharged from the direct-fired regeneration drying system, purify the air, and ensure that the discharged dry air is clean and pollution-free, making the air in the room fresh and dust-free.

[0033] Exemplarily, a third filter 13 is connected between the burner 8 and the regeneration zone 4 , and the third filter 13 can filter dust contained in the fresh air and solid dust that may be generated after combustion by the burner 8 .

[0034] For example, Figure 2 As shown, the liquid outlet of the waste heat recovery device 9 is connected to the liquid inlet of the reheater 6 through a first liquid infusion pipe 14, and the liquid outlet of the reheater 6 is connected to the liquid inlet of the waste heat recovery device 9 through a second liquid infusion pipe 15. The first liquid infusion pipe 14 is provided with a second solenoid valve 16, a water pump 17 and a flow limiting valve 18 in sequence along the water flow direction. Such a design can control the liquid flow from the waste heat recovery device 9 to the reheater 6 through the water pump 17 and the flow limiting valve 18, thereby controlling the liquid capacity in the reheater 6, and indirectly controlling the heat exchange temperature between the liquid in the reheater 6 and the drying air.

[0035] Exemplarily, the direct-fired regeneration drying system further includes a liquid storage tank 19, the liquid inlet end of the liquid storage tank 19 is connected to the first liquid infusion pipe 14 through a third liquid infusion pipe 20, and the liquid inlet end of the third liquid infusion pipe 20 is located between the liquid outlet end of the waste heat recovery device 9 and the second solenoid valve 16, and a third solenoid valve 21 is provided on the third liquid infusion pipe 20, the liquid outlet end of the liquid storage tank 19 is connected to the first liquid infusion pipe 14 through a fourth liquid infusion pipe 22, and the liquid outlet end of the fourth liquid infusion pipe 22 is located between the second solenoid valve 16 and the water pump 17, and a fourth solenoid valve 23 is provided on the fourth liquid infusion pipe 22. Specifically, the liquid storage tank 19 contains antifreeze.

[0036] In this embodiment, Figure 3 The burner 8 shown in the figure includes an igniter 81 and a gas nozzle 82, the gas nozzle 82 is connected to the gas supply device through a gas channel 83, a first solenoid valve 84 is provided on the gas channel 83, and the igniter 81 is arranged at the nozzle of the gas nozzle 82. Specifically, the distance between the igniter 81 and the gas nozzle 82 is 2mm-3mm.

[0037] Exemplarily, the drying material is a honeycomb-shaped paper fiber material, on which lithium bromide is evenly provided. Lithium bromide is highly soluble in water, has stable properties, and is not easily deteriorated or decomposed in the atmosphere.

[0038] Based on the above direct-fired regeneration drying system, an embodiment of the present invention further provides a method for using the direct-fired regeneration drying system, comprising the following steps:

[0039] Start the first fan 7, the fresh air is filtered through the first filter 11 and then enters the surface cooler 5 for cooling. After cooling, the clean air enters the drying area 3 of the rotary dryer 1 for drying and dehumidification. After drying and dehumidification, the dry air enters the reheater 6 for heating. After heating, the dry air passes through the second filter 12 and is discharged after filtering.

[0040] The drying material in the rotary dryer 1 is switched between the drying zone 3 and the regeneration zone 4 by the rotation of the rotary wheel 2. When the drying material is in the drying zone 3, the drying material dries the fresh air; the first filter 11 can filter the fresh air entering the direct-fired regeneration drying system, purify the air, and prevent particulate impurities in the air from damaging the dryer; the second filter 12 can filter the dry air discharged from the direct-fired regeneration drying system, purify the air, and ensure that the discharged dry air is clean and pollution-free, making the air in the room fresh and dust-free.

[0041] The second blower 10 is started, and the fresh air is heated to a predetermined temperature by the burner 8, and then filtered by the third filter 13. The filtered hot air enters the regeneration zone 4 of the rotary dryer 1, and evaporates the moisture of the drying material in the regeneration zone 4. The hot air after moisture absorption enters the waste heat recovery device 9, and exchanges heat with the liquid in the waste heat recovery device 9. After the heat exchange is completed, the hot air is discharged;

[0042] When the drying material is located in the regeneration zone 4, the moisture on the drying material is evaporated and taken out by the hot air, thereby restoring the dehumidification function of the drying material; the hot air after heating exchanges heat with the liquid in the waste heat recovery device 9, providing heat for the liquid in the waste heat recovery device 9; the third filter 13 can filter the dust carried in the fresh air and the solid dust that may be generated after combustion by the burner 8.

[0043] After the liquid in the waste heat recovery device 9 completes heat exchange, it flows into the reheater 6 and heats the drying air after drying and dehumidification. After the liquid in the reheater 6 completes heating the drying air, it flows back to the waste heat recovery device 9 to form a cycle.

[0044] After the liquid in the waste heat recovery device 9 completes the heat exchange, it flows into the reheater 6 and heats the dried drying air. After the liquid in the reheater 6 completes the heat exchange, it flows back to the waste heat recovery device 9 to form a cycle, so that the liquid circulates between the waste heat recovery device 9 and the reheater 6 for heat exchange, saving water resources and ensuring that the heat exchange process is stable and continuous; the hot air can not only dehumidify the drying material, but also indirectly heat the drying air. Compared with the prior art that uses power as a heat source, the present invention uses the heat source of hot air as a heat source, which is green, environmentally friendly and energy-saving.

[0045] Exemplarily, the liquid outlet of the waste heat recovery device 9 is connected to the liquid inlet of the reheater 6 via a first liquid infusion pipe 14, and the liquid outlet of the reheater 6 is connected to the liquid inlet of the waste heat recovery device 9 via a second liquid infusion pipe 15. A second solenoid valve 16, a water pump 17 and a flow limiting valve 18 are sequentially provided on the first liquid infusion pipe 14 along the water flow direction;

[0046] The direct-fired regeneration drying system further includes a liquid storage tank 19, the liquid inlet end of the liquid storage tank 19 is connected to the first liquid infusion pipe 14 through a third liquid infusion pipe 20, and the liquid inlet end of the third liquid infusion pipe 20 is located between the liquid outlet end of the waste heat recovery device 9 and the second solenoid valve 16, and a third solenoid valve 21 is provided on the third liquid infusion pipe 20, the liquid outlet end of the liquid storage tank 19 is connected to the first liquid infusion pipe 14 through a fourth liquid infusion pipe 22, and the liquid outlet end of the fourth liquid infusion pipe 22 is located between the second solenoid valve 16 and the water pump 17, and a fourth solenoid valve 23 is provided on the fourth liquid infusion pipe 22;

[0047] When working, the following steps are included:

[0048] Step 1, close the second solenoid valve 16, open the third solenoid valve 21, the fourth solenoid valve 23 and the flow limiting valve 18, the liquid in the liquid storage tank 19 enters the water pump 17 through the fourth liquid infusion pipe 22, and then enters the reheater 6 through the first liquid infusion pipe 14 and the flow limiting valve 18, and heats the dry air after dehumidification. After the liquid is heated in the reheater 6, it enters the waste heat recovery device 9 through the second liquid infusion pipe 15, and exchanges heat with the hot air after moisture absorption. After the liquid completes heat exchange in the waste heat recovery device 9, it flows back to the liquid storage tank 19 through the first liquid infusion pipe 14 and the third liquid infusion pipe 20 to form a cycle;

[0049] Such a design can allow the liquid to fill the reheater 6, the waste heat recovery device 9 and the liquid infusion pipe, effectively discharge the air in the reheater 6, the waste heat recovery device 9 and the liquid infusion pipe, ensure the heat exchange stability of the reheater 6 and the waste heat recovery device 9, and ensure the normal operation of the heat exchange process.

[0050] Step 2: After the heat exchange between the reheater 6 and the waste heat recovery device 9 is stable, open the second solenoid valve 16, close the third solenoid valve 21 and the fourth solenoid valve 23, and after the liquid completes the heat exchange in the waste heat recovery device 9, it enters the water pump 17 through the first infusion pipe 14, and enters the reheater 6 through the limiting valve 18 to heat the dry air after dehumidification. After the liquid is heated in the reheater 6, it flows back to the waste heat recovery device 9 through the second infusion pipe 15 to form a cycle.

[0051] With this design, the liquid circulates between the reheater 6 and the waste heat recovery device 9, which can ensure stable heat exchange between the reheater 6 and the waste heat recovery device 9, save water, be environmentally friendly, and reduce operating costs.

[0052] In the description of the present invention, it should be understood that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" used in the present invention should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0053] The above disclosure is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A method for using a direct-fired regeneration drying system, characterized in that: The direct-fired regeneration drying system comprises a rotary dryer, the rotary dryer comprises a rotor, a drying material for drying airflow is arranged on the rotor, the rotary dryer comprises a drying zone located at the bottom and a regeneration zone located at the top, the drying material is switched between the drying zone and the regeneration zone by the rotation of the rotor, the air inlet end of the drying zone is connected with a surface cooler, the air outlet end of the drying zone is connected with a reheater and a first fan in sequence, the air inlet end of the regeneration zone is connected with a burner, the air outlet end of the regeneration zone is connected with a waste heat recovery device and a second fan in sequence, the liquid outlet end of the waste heat recovery device is connected with the liquid inlet end of the reheater, the liquid outlet end of the reheater is connected with the liquid inlet end of the waste heat recovery device, the liquid outlet end of the waste heat recovery device is connected with the liquid inlet end of the reheater, the liquid outlet end of the waste heat recovery device is connected with the liquid inlet end of the reheater through a first liquid infusion pipe, and the liquid outlet end of the reheater is connected with the waste heat recovery device. The liquid inlet ends of the waste heat recovery device are connected through a second liquid infusion pipe, and a second solenoid valve, a water pump and a flow limiting valve are sequentially arranged on the first liquid infusion pipe along the water flow direction, and the liquid flow from the waste heat recovery device to the reheater is controlled by the water pump and the flow limiting valve, thereby controlling the liquid capacity in the reheater, and indirectly controlling the heat exchange temperature between the liquid and the drying air in the reheater; the direct-fired regeneration drying system also includes a liquid storage tank, the liquid inlet end of the liquid storage tank is connected to the first liquid infusion pipe through a third liquid infusion pipe, and the liquid inlet end of the third liquid infusion pipe is located between the liquid outlet end of the waste heat recovery device and the second solenoid valve, a third solenoid valve is arranged on the third liquid infusion pipe, and the liquid outlet end of the liquid storage tank is connected to the first liquid infusion pipe through a fourth liquid infusion pipe, and the liquid outlet end of the fourth liquid infusion pipe is located between the second solenoid valve and the water pump, and a fourth solenoid valve is arranged on the fourth liquid infusion pipe; When working, the following steps are included: Step 1: close the second solenoid valve, open the third solenoid valve, the fourth solenoid valve and the flow limiting valve, the liquid in the liquid storage tank enters the water pump through the fourth liquid infusion pipe, enters the reheater through the first liquid infusion pipe and the flow limiting valve, and heats the dry air after drying and dehumidification. After the liquid is heated in the reheater, it enters the waste heat recovery device through the second liquid infusion pipe and exchanges heat with the hot air after moisture absorption. After the liquid completes heat exchange in the waste heat recovery device, it flows back to the liquid storage tank through the first and third liquid infusion pipes to form a cycle; Step 2: After the heat exchange between the reheater and the waste heat recovery device is stable, open the second solenoid valve, close the third solenoid valve and the fourth solenoid valve. After the liquid completes the heat exchange in the waste heat recovery device, it enters the water pump through the first infusion pipe, and enters the reheater through the limiting valve to heat the dry air after drying and dehumidification. After the liquid completes the heating in the reheater, it flows back to the waste heat recovery device through the second infusion pipe to form a cycle.

2. The method for using a direct-fired regeneration drying system according to claim 1, characterized in that: The air inlet end of the surface cooler is connected to a first filter, and the air outlet end of the first fan is connected to a second filter.

3. The method for using a direct-fired regeneration drying system according to claim 1, characterized in that: A third filter is connected between the burner and the regeneration zone.

4. The method for using a direct-fired regeneration drying system according to claim 1, characterized in that: The burner comprises an igniter and a gas nozzle. The gas nozzle is connected to a gas supply device through a gas channel. A first solenoid valve is arranged on the gas channel. The igniter is arranged at the nozzle of the gas nozzle.

5. The method for using a direct-fired regeneration drying system according to claim 1, characterized in that: The drying material is a honeycomb-shaped paper fiber material, and lithium bromide is evenly arranged on the paper fiber material.

6. The method for using a direct-fired regeneration drying system according to claim 1, characterized in that: The liquid storage tank is filled with antifreeze liquid.

7. A method for using a direct-fired regeneration drying system according to any one of claims 1 to 6, characterized in that: The following steps are involved: Start the first fan, the fresh air enters the surface cooler for cooling, the clean air after cooling enters the drying area of ​​the rotary dryer for drying and dehumidification, the dry air after drying and dehumidification enters the reheater for heating, and the dry air after heating is discharged; Start the second fan, and the fresh air is heated to a predetermined temperature by the burner, and then enters the regeneration area of ​​the rotary dryer, and evaporates the moisture of the drying material in the regeneration area. The hot air after moisture absorption enters the waste heat recovery device, and exchanges heat with the liquid in the waste heat recovery device. After the heat exchange is completed, the warm air is discharged; After the liquid in the waste heat recovery device completes heat exchange, it flows into the reheater and heats the dry air after drying and dehumidification. After the liquid in the reheater completes heating the dry air, it flows back to the waste heat recovery device to form a cycle.

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