JP2006300364A - Exhaust heat recovering and utilizing device and exhaust heat recovering and utilizing method for hot air ventilating dryer with sensible heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust heat recovering and utilizing device and an exhaust heat recovering and utilizing method for a hot air ventilating dryer with a sensible heat exchanger that can reduce electric power of a heater. <P>SOLUTION: The exhaust heat recovering and utilizing device comprises the hot air ventilating dryer for heating outside air sucked by a blower 19, by the heater 20 to produce hot air, using the hot air to dry thermoplastic resin in a resin drying tank 22, and then filtering the hot air by an exhaust filter 24 to exhaust it; peripheral equipment 13 exhausting warm air higher in temperature than outside air, from an exhaust port; and a sensible heat exchanger 17 connecting one passage to an intake port of a blower 19 by an intake duct 18 while connecting other passages to the exhaust port of the peripheral equipment 13 by an exhaust heat utilizing exhaust duct 14 and to an exhaust port of the exhaust filter 24 by an exhaust heat recovering exhaust duct 10 and exchanging heat between outside air passing through the one passage and warm air passing through the other passages. The exhaust heat utilizing exhaust duct 14 and the exhaust heat recovering exhaust duct 10 are provided with temperature detectors 15, 11 for detecting the temperature of warm air passing through the exhaust ducts 14, 10, and exhaust direction selector valves 16, 12 respectively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an exhaust heat recovery utilization device and an exhaust heat recovery utilization method of a hot air ventilation dryer with a sensible heat exchanger for drying a thermoplastic resin.

  Conventionally, this type of technology sucks the outside air with a blower, heats the outside air introduced with the blower to a set temperature with a heater to generate hot air, and blows the hot air into a resin drying tank for use in drying thermoplastic resin. Then, the warm air whose temperature has decreased after the drying treatment is filtered by an exhaust filter and discharged to the outside.

  However, when the difference between the outside air temperature and the set temperature is large as in winter, there is a problem that the energization time of the heater for heating the outside air induced by the blower to the set temperature becomes long and the power cost is increased.

  Therefore, the temperature of the induced hot air and the set temperature are obtained by performing sensible heat exchange between the exhausted air exhausted to the outside using a sensible heat exchanger and the outside air induced by the blower to convert the outside air into warm air. In recent years, there has been proposed a method for recovering exhaust heat from a hot air ventilation dryer that reduces the difference between the heaters and shortens the energization time of the heater, thereby reducing power consumption.

  That is, according to this exhaust heat recovery method, only the heat of the exhaust heat air exhausted to the outside by the sensible heat exchanger can be recovered and transmitted to the outside air induced by the blower, so the amount of heat heated by the heater can be reduced. Since it can be made small, energy can be saved (see, for example, Patent Document 1).

  6 to 7 are a front view and a side view of a waste heat recovery device of a conventional hot-air aeration dryer with a sensible heat exchanger described in Patent Document 1, respectively.

  As shown in FIGS. 6 to 7, the hot air ventilation dryer with a sensible heat exchanger is provided with a resin drying tank 1 for discharging hot air after drying a thermoplastic resin, an exhaust port 2 and an outside air port 3. The sensible heat exchanger 4, a blower 5 that sucks and discharges outside air, and a heating unit 6 that heats the discharged outside air to a set temperature.

  The sensible heat exchanger 4 is connected to the resin drying tank 1 through an exhaust duct 7 and is connected to a blower 5 through an exhaust heat recovery exhaust duct 8 to exchange sensible heat between outside air and exhaust heat. Do.

  The blower 5 is connected to the resin drying tank 1 through the heating unit 6 and the connecting pipe 9, sucks outside air from the outside air port 3, and heats the warm air that has been subjected to sensible heat exchange by the sensible heat exchanger 4. To the set temperature and discharged to the resin drying tank 1.

  As a result, the hot air ventilation dryer with sensible heat exchanger can recover the exhaust heat, shorten the energization time of the heater by reducing the difference between the temperature of the induced hot air and the set temperature, and save power. Can be reduced.

As described above, the hot air ventilation dryer with a sensible heat exchanger can send warm air to the heating unit 6 by transmitting the exhaust heat air discharged from the resin drying tank 1 to the outside air guided by the blower 5. The amount of heat heated by the heating unit 6 can be reduced, and the time for heating to the set temperature can be shortened accordingly.
Japanese Patent Laid-Open No. 2000-111253

  However, in the above conventional configuration, the temperature of the exhaust heat air discharged from the resin drying tank 1 is unstable, and the temperature of the thermoplastic resin in the resin drying tank 1 is not raised to the set temperature, so that drying is possible. If not, the warm air induced in the resin drying tank 1 is deprived of heat to dry the thermoplastic resin, and the temperature of the warm air discharged from the resin drying tank 1 is close to the outside air temperature, gradually. Since the heat is not taken away when dried, the temperature of the warm air discharged from the resin drying tank 1 is raised to the vicinity of the set temperature, but although not shown, the dried thermoplastic resin is used for production. When the thermoplastic resin that has been taken out of the drying tank 1 and has not been dried is fed into the resin drying tank 1, the warm air that has been guided into the resin drying tank 1 again becomes hot to dry the thermoplastic resin. Since the temperature is lowered to the vicinity of the outside air temperature, and when it is gradually dried, the temperature of the warm air discharged from the resin drying tank 1 rises to the vicinity of the set temperature during the production. There is a problem that the temperature of warm air that is unstable and is induced from the blower 5 cannot always be higher than the outside air temperature.

  An object of the present invention is to solve the above-described conventional problems, and to provide an exhaust heat recovery utilization device and an exhaust heat recovery utilization method of a hot air ventilation dryer with a sensible heat exchanger capable of reducing the electric power of a heater. And

  In order to achieve the above object, the exhaust heat recovery utilization device and exhaust heat recovery utilization method of the hot-air aeration dryer with sensible heat exchanger of the present invention are designed to heat the outside air induced by the blower from the outside through the exhaust port. The warm air of peripheral equipment that discharges high warm air is also used.

  As a result, the amount of heat to be heated to the set temperature can be reduced by relatively reducing the difference between the temperature of the warm air induced by the blower and the set temperature, so that the power of the heater can be reduced.

  According to the exhaust heat recovery utilization device and the exhaust heat recovery utilization method of the hot air ventilation dryer with sensible heat exchanger of the present invention, the power of the heater can be reduced and the drying time can be shortened.

  The invention of the exhaust heat recovery and utilization device of the hot air ventilation dryer with a sensible heat exchanger according to claim 1, wherein the outside air sucked by a blower is heated by a heater to be hot air, and the hot air is used as a thermoplastic resin in a resin drying tank. A hot air ventilation dryer that is filtered by an exhaust filter and exhausted, peripheral equipment that exhausts hot air having a temperature higher than the outside air from the exhaust port, and one passage is connected to the intake port of the blower by an intake duct And the other passage is connected to the exhaust port of the peripheral device by the exhaust heat utilization exhaust duct and connected to the exhaust port of the exhaust filter by the exhaust heat recovery exhaust duct, and the outside air passing through the one passage A sensible heat exchanger that exchanges heat with the warm air passing through the other passage, and the exhaust heat utilization exhaust duct uses exhaust heat to detect the temperature of the warm air that passes through the exhaust heat utilization exhaust duct. Excretion Based on the temperature detected by the temperature detector and the exhaust heat utilization exhaust temperature detector, the hot air passing through the exhaust heat utilization exhaust duct is guided to the sensible heat exchanger or directed to the sensible heat exchanger. The exhaust heat utilization exhaust direction switching valve for selectively switching whether to exhaust outside the exhaust heat utilization exhaust duct is provided, and the exhaust heat recovery exhaust duct is configured to supply hot air passing through the exhaust heat recovery exhaust duct. Based on the temperature detected by the exhaust heat recovery exhaust gas temperature detector and the temperature detected by the exhaust heat recovery exhaust gas temperature detector, whether the hot air passing through the exhaust heat recovery exhaust duct is guided to the sensible heat exchanger An exhaust heat recovery exhaust direction switching valve for selectively switching whether to exhaust outside the exhaust heat recovery exhaust duct without being led to the sensible heat exchanger is provided.

  In this way, in addition to the exhaust heat of the hot air ventilation dryer (hot air exhausted from the exhaust filter exhaust port) to heat the outside air sucked in by the blower, the surroundings discharge hot air having a temperature higher than the outside air from the exhaust port Since the warm air of the equipment is also used, the temperature of the outside air sucked by the blower rises and the amount of heat to be heated to the set temperature can be reduced as compared with the conventional case, so that the heater power can be reduced.

  The exhaust heat exhaust duct and exhaust heat recovery exhaust duct each have a temperature detector that detects the temperature of hot air passing through the exhaust duct and an exhaust direction switching valve. By controlling the exhaust direction switching valve well, the temperature of the outside air sucked in by the blower can be increased well.

  The invention of the exhaust heat recovery and utilization device of the hot air ventilation dryer with a sensible heat exchanger according to claim 2 is the invention according to claim 1, wherein the outside air whose temperature has been increased by heat exchange in the sensible heat exchanger is dehumidified. A moisture absorbent is provided in the air path between the sensible heat exchanger and the blower.

  As a result, the absolute humidity of the dehumidified hot air is lowered, so that the amount of moisture entering the resin drying tank is reduced, and the drying time can be reduced.

  The invention of the exhaust heat recovery and utilization method of the hot air aeration dryer with sensible heat exchanger according to claim 3 is the invention using the exhaust heat recovery and utilization device of the hot air aeration dryer with sensible heat exchanger according to claim 1. Exhaust heat recovery method for hot air ventilation dryer with heat exchanger, if the temperature detected by the exhaust heat exhaust temperature detector is higher than the temperature detected by the exhaust heat recovery exhaust temperature detector The exhaust heat utilization exhaust direction switching valve is controlled so as to guide the hot air passing through the duct to the sensible heat exchanger, and the hot air passing through the exhaust heat recovery exhaust duct is not led to the sensible heat exchanger. The exhaust heat recovery exhaust direction switching valve is controlled so as to be discharged out of the exhaust heat recovery exhaust duct, and conversely, the temperature detected by the exhaust heat utilization exhaust temperature detector is detected by the exhaust heat recovery exhaust temperature detector. If the temperature is lower than the The exhaust heat utilization exhaust direction switching valve is controlled so that the passing hot air is exhausted out of the exhaust heat utilization exhaust duct without being guided to the sensible heat exchanger, and passes through the exhaust heat recovery exhaust duct. The exhaust heat recovery exhaust direction switching valve is controlled so as to guide the warm air to be conducted to the sensible heat exchanger.

  As a result, when there is a difference in the temperature of the hot air passing through the exhaust duct between the exhaust heat utilization exhaust duct and the exhaust heat recovery exhaust duct, only the hot air with the higher temperature is guided to the sensible heat exchanger. Therefore, the temperature of the outside air sucked in by the blower can be raised well.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiment.

(Embodiment 1)
FIG. 1 is a configuration diagram of an exhaust heat recovery and utilization device of a hot air ventilation dryer with a sensible heat exchanger according to the first embodiment, and FIG. 2 is an exhaust heat recovery of the hot air ventilation dryer with a sensible heat exchanger according to the first embodiment. FIG. 3 is a flowchart of the method of use. FIG. 3 shows the time and operating state when the temperature of exhaust heat air discharged from the exhaust filter of the first embodiment changes higher and lower than the temperature of exhaust heat air discharged from peripheral equipment. It is a characteristic view which shows a relationship.

  In FIG. 1, the exhaust heat recovery exhaust duct 10 guides exhaust heat air exhausted from the exhaust filter 24 to the sensible heat exchanger 17. The exhaust heat recovery exhaust gas temperature detector 11 detects the temperature of the induced exhaust heat air. The exhaust heat recovery exhaust direction switching valve 12 converts the exhaust heat air exhausted from the exhaust filter 24 into a sensible heat exchanger if the exhaust heat air temperature exhausted from the exhaust filter 24 is higher than the exhaust heat air temperature exhausted from the peripheral device 13. It is controlled to flow to 17, and if it is low, it is controlled to flow to the outside.

  The peripheral device 13 discharges exhaust heat air. The exhaust heat utilization exhaust duct 14 guides exhaust heat air exhausted from the peripheral device 13 to the sensible heat exchanger 17. The exhaust heat utilization exhaust gas temperature detector 15 detects the temperature of the induced exhaust heat air. If the exhaust heat air temperature exhausted from the peripheral device 13 is higher than the exhaust heat air temperature exhausted from the exhaust filter 24, the exhaust heat utilization exhaust direction switching valve 16 converts the exhaust heat air exhausted from the peripheral device 13 into a sensible heat exchanger. It is controlled to flow to 17, and if it is low, it is controlled to flow to the outside.

  The sensible heat exchanger 17 exchanges sensible heat between the exhaust heat air discharged from the exhaust filter 24 or the peripheral device 13 and the outside air, and raises the outside air to warm air. The intake duct 18 guides warm air to the blower 19. The blower 19 sucks and discharges the warm air guided by the intake duct 18.

  The heater 20 heats the discharged warm air to a set temperature to generate hot air. The connecting pipe 21 guides hot air heated to the set temperature to the resin drying tank 22. The resin drying tank 22 dries the thermoplastic resin stored in the tank by hot air guided to the lower part of the tank by the connecting pipe 21.

  The exhaust connection pipe 23 guides warm air rising in the tank to the exhaust filter 24 while drying the thermoplastic resin. The exhaust filter 24 filters the warm air induced by the exhaust connection pipe 23 and discharges it to the outside.

  The exhaust heat utilization device of the hot air ventilation dryer with sensible heat exchanger of Embodiment 1 is configured as the exhaust heat recovery device of the conventional hot air ventilation dryer with sensible heat exchanger shown in FIGS. In addition to recovering and using the exhaust heat from the exhaust filter 24, the exhaust heat recovery exhaust temperature detector 11 further detects the temperature of the exhaust heat air exhausted from the exhaust filter 24 in order to use the exhaust heat from the peripheral device 13. If the exhaust heat air temperature exhausted from the exhaust filter 24 is higher than the exhaust heat air temperature exhausted from the peripheral device 13, the exhaust heat air exhausted from the exhaust filter 24 is controlled to flow to the sensible heat exchanger 17. Conversely, exhaust heat recovery exhaust direction switching valve 12 that controls to flow to the outside if low, peripheral device 13 that exhausts exhaust heat air at a temperature higher than the outside air temperature, and exhaust heat air that is exhausted from peripheral device 13 Inducing exhaust heat exhaust 14, the exhaust heat utilization exhaust temperature detector 15 for detecting the temperature of exhaust heat air induced from the exhaust heat utilization exhaust duct 14, and the exhaust heat air temperature exhausted from the peripheral device 13 is exhausted from the exhaust filter 24. If the exhaust heat air temperature is higher than the exhaust heat air temperature, the exhaust heat exhaust gas is controlled so that the exhaust heat air discharged from the peripheral device 13 flows to the sensible heat exchanger 17. Are provided.

  The operation and action of the exhaust heat recovery and utilization device of the hot air ventilation dryer with the sensible heat exchanger configured as described above will be described below with reference to FIGS.

  As STEP 50 in FIG. 2, the operation of the exhaust heat recovery and utilization device and the peripheral device of the hot air ventilation dryer with sensible heat exchanger is started, and STEP 50 is completed, and then STEP 51 is entered.

  In STEP 51, the exhaust heat air temperature exhausted from the exhaust filter 24 detected by the exhaust heat recovery exhaust gas temperature detector 11 is higher than the exhaust heat air temperature exhausted from the peripheral device 13 detected by the exhaust heat utilization exhaust gas temperature detector 15. If this is the case, STEP 51 ends and STEP 52 is entered. If the exhaust heat air temperature discharged from the exhaust filter 24 detected by the exhaust heat recovery exhaust temperature detector 11 is lower than the exhaust heat air temperature discharged from the peripheral device 13 detected by the exhaust heat utilization exhaust temperature detector 15. STEP 51 ends, and the process enters STEP 53.

  STEP 52 sends exhaust heat air discharged from the exhaust filter 24 from the exhaust heat recovery exhaust direction switching valve 12 to the sensible heat exchanger 17, and exhaust heat air exhausted from the peripheral device 13 from the exhaust heat utilization exhaust direction switching valve 16. Is discharged to the outside, and STEP 52 is completed, and then STEP 51 is entered.

  STEP 53 exhausts exhaust heat air exhausted from the exhaust filter 24 from the exhaust heat recovery exhaust direction switching valve 12 to the outside, and exhaust heat air exhausted from the peripheral device 13 from the exhaust heat utilization exhaust direction switching valve 16 is sensible heat. It sends out to the exchanger 17, and STEP52 is complete | finished, and enters STEP51.

  Next, the time and operation state when the temperature of the exhaust heat air discharged from the exhaust filter 24 changes higher and lower than the temperature of the exhaust heat air discharged from the peripheral device 13 will be described.

  In FIG. 3, when the temperature of the exhaust heat air exhausted from the exhaust filter 24 changes higher than the exhaust heat air temperature exhausted from the peripheral device 13, the exhaust heat exhausted from the exhaust filter 24 from the exhaust heat recovery exhaust direction switching valve 12. The air is sent to the sensible heat exchanger 17 and the exhaust heat recovery operation is performed to exhaust the exhaust heat air exhausted from the peripheral device 13 from the exhaust heat utilization exhaust direction switching valve 16 to the outside. When the temperature of the exhaust heat air changes lower than the exhaust heat air temperature exhausted from the peripheral device 13, the exhaust heat air exhausted from the exhaust filter 24 from the exhaust heat recovery exhaust direction switching valve 12 is exhausted to the outside for use of the exhaust heat. An example of performing exhaust heat utilization operation in which exhaust heat air exhausted from the peripheral device 13 from the exhaust direction switching valve 16 is sent to the sensible heat exchanger 17 is shown.

  If there is substantially no temperature difference between the temperature of the exhaust heat air exhausted from the exhaust filter 24 and the temperature of the exhaust heat air exhausted from the peripheral device 13, the exhaust heat air exhausted from the exhaust filter 24 and the peripheral device You may make it send both the waste heat air discharged | emitted from 13 to the sensible heat exchanger 17. FIG.

  The exhaust heat recovery and utilization device of the hot air ventilation dryer with a sensible heat exchanger according to the present embodiment heats the outside air sucked by the blower 19 with the heater 20 to form hot air, and the hot air is made of the thermoplastic resin in the resin drying tank 22. After being used for drying, the hot air ventilation dryer that is filtered and exhausted by the exhaust filter 24, the peripheral device 13 that exhausts hot air having a temperature higher than the outside air from the exhaust port, and one passage is connected to the blower 19 by the intake duct 18. The other passage is connected to the exhaust port of the peripheral device 13 by the exhaust heat utilization exhaust duct 14 and connected to the exhaust port of the exhaust filter 24 by the exhaust heat recovery exhaust duct 10 and passes through the one passage. The exhaust heat utilization exhaust duct 14 detects the temperature of the warm air passing through the exhaust heat utilization exhaust duct 14. The sensible heat exchanger 17 exchanges heat between the outside air and the warm air passing through the other passage. Based on the temperature detected by the exhaust heat utilization exhaust temperature detector 15 and the temperature detected by the exhaust heat utilization exhaust temperature detector 15, the hot air passing through the exhaust heat utilization exhaust duct 14 is guided to the sensible heat exchanger 17 or sensible heat. An exhaust heat utilization exhaust direction switching valve 16 that selectively switches whether to exhaust outside the exhaust heat utilization exhaust duct 14 without being led to the exchanger 17, and the exhaust heat recovery exhaust duct 10 is provided with the exhaust heat recovery exhaust duct 10. Based on the temperature detected by the exhaust heat recovery exhaust gas temperature detector 11 and the temperature detected by the exhaust heat recovery exhaust gas temperature detector 11, the hot air passing through the exhaust heat recovery exhaust air duct 10 is detected. By providing the exhaust heat recovery exhaust direction switching valve 12 for selectively switching between the exhaust heat recovery exhaust duct 10 and the exhaust heat recovery exhaust duct 10 without being guided to the sensible heat exchanger 17 or led to the sensible heat exchanger 17, 19 to heat the outside air sucked by In addition to the exhaust heat of the air ventilation dryer (warm air discharged from the exhaust port of the exhaust filter 24), the warm air of the peripheral device 13 that exhausts hot air having a temperature higher than the outside air from the exhaust port is also used. As a result, the temperature of the outside air sucked by the blower 19 rises and the amount of heat to be heated to the set temperature can be reduced, so that the power of the heater 20 can be reduced.

  Further, the exhaust heat utilization exhaust duct 14 and the exhaust heat recovery exhaust duct 10 are respectively provided with temperature detectors 15 and 11 for detecting the temperature of hot air passing through the exhaust ducts 14 and 10 and exhaust direction switching valves 16 and 12. Therefore, the temperature of the outside air sucked in by the blower 19 can be well raised by controlling the exhaust direction switching valves 16 and 12 according to each temperature condition.

  When the temperature detected by the exhaust heat utilization exhaust temperature detector 15 is higher than the temperature detected by the exhaust heat recovery exhaust temperature detector 11, the sensible heat exchanger 17 converts the warm air passing through the exhaust heat utilization exhaust duct 14. The exhaust heat utilization exhaust direction switching valve 16 is controlled so as to lead to the exhaust air, and the warm air passing through the exhaust heat recovery exhaust duct 10 is discharged outside the exhaust heat recovery exhaust duct 10 without being guided to the sensible heat exchanger 17. If the temperature detected by the exhaust heat recovery exhaust gas temperature detector 15 is lower than the temperature detected by the exhaust heat recovery exhaust gas temperature detector 11, the exhaust heat recovery exhaust gas direction switching valve 12 is controlled. While controlling the exhaust heat utilization exhaust direction switching valve 16 so that the warm air passing through the utilization exhaust duct 14 is discharged outside the exhaust heat utilization exhaust duct 14 without being guided to the sensible heat exchanger 17, exhaust heat recovery is performed. The temperature that passes through the exhaust duct 10 The exhaust heat recovery exhaust direction switching valve 12 is controlled so as to guide the exhaust gas to the sensible heat exchanger 17, thereby passing through the exhaust ducts 14 and 10 of the exhaust heat utilization exhaust duct 14 and the exhaust heat recovery exhaust duct 10. When there is a difference in the temperature of the warm air, only the warm air having the higher temperature is guided to the sensible heat exchanger 17 so that the temperature of the outside air sucked by the blower 19 can be increased.

  From the above, the difference between the temperature of the hot air induced by the blower 19 and the set temperature is relatively reduced by sensible heat exchange between the exhaust heat air discharged from the exhaust filter 24 or the peripheral device 13 and the outside air. As a result, the amount of heat to be heated to the set temperature can be reduced, so that the energization time of the heater 20 can be shortened and the power can be reduced.

  Compared with the exhaust heat recovery utilization device of the hot air ventilation dryer with sensible heat exchanger of this embodiment and the exhaust heat recovery device of the conventional hot air ventilation dryer with sensible heat exchanger, the power consumption is clearly significant. It was possible to save and confirm that the power consumption was reduced by about 14.3% compared to the conventional technology.

(Embodiment 2)
FIG. 4 is a configuration diagram of the exhaust heat recovery and utilization device of the hot air ventilation dryer with a sensible heat exchanger in the second embodiment, and FIG. 5 is a moisture absorption showing the relationship between the relative humidity and the moisture absorption rate of the hygroscopic agent in the second embodiment. FIG.

  In addition, about the same structure as Embodiment 1, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  The difference between the second embodiment and the first embodiment is that, in the first embodiment, the sensible heat exchanged hot air is sucked into the blower 19 without dehumidification, but in the second embodiment, the sensible heat exchange is performed. The hot air differs in that it is dehumidified by the hygroscopic agent 25 and sucked into the blower 19.

  That is, the dehumidified warm air is sent into the resin drying tank 22. Thereby, even when the absolute humidity is high and the weather is bad, the absolute humidity of the warm air sucked by the blower 19 is lowered and the thermoplastic resin is dried. Therefore, when the thermoplastic resin is dried with warm air without dehumidification. Compared to the drying time.

  As shown in FIG. 4, in addition to the configuration of the first embodiment, the present embodiment includes a sensible heat exchanger 17 that includes a hygroscopic agent 25 that dehumidifies the outside air whose temperature has been increased by heat exchange in the sensible heat exchanger 17. And the blower 19 (provided in the outlet of the sensible heat exchanger 17). The hygroscopic agent 25 dehumidifies the warm air subjected to sensible heat exchange.

  The operation and action of the exhaust heat recovery and utilization device of the hot air ventilation dryer with the sensible heat exchanger configured as described above will be described below with reference to FIG.

  In FIG. 5, the dehumidifying agent 25 has a characteristic that the moisture absorption rate increases as the relative humidity increases. That is, the moisture absorption rate increases as the amount of moisture in the air increases. Even when the absolute humidity is high and the weather is bad, the absolute humidity of the warm air sucked from the blower 19 is lowered by the dehumidifier 25 and the thermoplastic resin in the resin drying tank 22 is dried. The drying time is shorter than when the thermoplastic resin is dried.

  From the above, since the thermoplastic resin in the resin drying tank 22 is dried with warm air having a low absolute humidity by dehumidifying the warm air that has been subjected to sensible heat exchange, the thermoplastic resin is removed with warm air without dehumidification. Compared with the case where it dries, it can be clearly confirmed that the drying time can be significantly reduced and the drying time is reduced by about 5.0% compared to the conventional case.

  As described above, the exhaust heat recovery utilization device and the exhaust heat recovery utilization method of the hot air ventilation dryer with sensible heat exchanger according to the present invention provide exhaust heat that exhausts the outside air induced by the blower from the exhaust filter or peripheral equipment. By exchanging sensible heat with air, the amount of heat heated to the set temperature can be reduced by relatively reducing the difference between the temperature of the warm air induced by the blower and the set temperature, so the heater energization time can be shortened and the power can be reduced. Therefore, it can also be applied to energy-saving applications in dryers and drying furnaces that use outside air.

The block diagram of the waste heat recovery utilization apparatus of the hot air ventilation dryer with a sensible heat exchanger in Embodiment 1 of this invention Flow chart of exhaust heat recovery utilization method of hot air ventilation dryer with sensible heat exchanger of the embodiment The characteristic diagram which shows the relationship between the time and operation state when the temperature of the exhaust heat air discharged | emitted from the exhaust filter in the same embodiment changes higher than the exhaust heat air temperature discharged | emitted from a peripheral device, and when changed low The block diagram of the waste heat recovery utilization apparatus of the hot air ventilation dryer with a sensible heat exchanger in this Embodiment 2 of this invention Moisture absorption isotherm showing the relationship between relative humidity and moisture absorption rate of the hygroscopic agent of the same embodiment Front view of exhaust heat recovery device of conventional hot air ventilation dryer with sensible heat exchanger Side view of the exhaust heat recovery device of a conventional hot air ventilation dryer with sensible heat exchanger

Explanation of symbols

10 exhaust heat recovery exhaust duct 11 exhaust heat recovery exhaust temperature detector 12 exhaust heat recovery exhaust direction switching valve 13 peripheral equipment 14 exhaust heat utilization exhaust duct 15 exhaust heat utilization exhaust temperature detector 16 exhaust heat utilization exhaust direction switching valve 17 sensible heat Exchanger 18 Intake duct 19 Blower 20 Heater 22 Resin drying tank 24 Exhaust filter 25 Dehumidifier

Claims (3)

A hot air ventilation dryer that heats the outside air sucked by a blower with a heater to form hot air, uses the hot air to dry the thermoplastic resin in the resin drying tank, and then filters and exhausts the exhaust air;
Peripheral devices that discharge hot air at a higher temperature than the outside air from the exhaust port,
One passage is connected to the air inlet of the blower by an air intake duct, and the other passage is connected to the air outlet of the peripheral device by an exhaust heat utilization exhaust duct and is connected to the exhaust port of the exhaust filter by an exhaust heat recovery exhaust duct. A sensible heat exchanger for exchanging heat between the outside air passing through the one passage and the warm air passing through the other passage;
The exhaust heat utilization exhaust duct is based on the exhaust heat utilization exhaust temperature detector that detects the temperature of hot air passing through the exhaust heat utilization exhaust duct, and the temperature detected by the exhaust heat utilization exhaust temperature detector. Exhaust heat for selectively switching whether the hot air passing through the exhaust heat utilization exhaust duct is guided to the sensible heat exchanger or discharged outside the exhaust heat utilization exhaust duct without being guided to the sensible heat exchanger Use exhaust direction switching valve
The exhaust heat recovery exhaust duct is based on the exhaust heat recovery exhaust temperature detector that detects the temperature of hot air passing through the exhaust heat recovery exhaust duct, and the temperature detected by the exhaust heat recovery exhaust temperature detector. Exhaust heat for selectively switching whether the hot air passing through the exhaust heat recovery exhaust duct is guided to the sensible heat exchanger or discharged outside the exhaust heat recovery exhaust duct without being guided to the sensible heat exchanger An exhaust heat recovery and utilization device for a hot air ventilation dryer with a sensible heat exchanger, comprising a recovery exhaust direction switching valve.   2. The sensible heat exchanger according to claim 1, wherein a humectant for dehumidifying the outside air whose temperature has been increased by heat exchange in the sensible heat exchanger is provided in an air passage between the sensible heat exchanger and the blower. Waste heat recovery and utilization device for hot air ventilation dryers. An exhaust heat recovery and utilization method of a hot air ventilation dryer with a sensible heat exchanger using the exhaust heat recovery and utilization device of the hot air ventilation dryer with a sensible heat exchanger according to claim 1,
If the temperature detected by the exhaust heat exhaust temperature detector is higher than the temperature detected by the exhaust heat recovery exhaust temperature detector, the exhaust heat is exhausted so that the warm air passing through the exhaust heat exhaust duct is guided to the sensible heat exchanger. Exhaust heat recovery exhaust direction so as to control the use exhaust direction switching valve and to discharge the warm air passing through the exhaust heat recovery exhaust duct to the outside of the exhaust heat recovery exhaust duct without guiding it to the sensible heat exchanger Control the switching valve,
Conversely, when the temperature detected by the exhaust heat utilization exhaust temperature detector is lower than the temperature detected by the exhaust heat recovery exhaust temperature detector, the hot air passing through the exhaust heat utilization exhaust duct is exchanged with the sensible heat exchange. The exhaust heat utilization exhaust direction switching valve is controlled so as to be discharged out of the exhaust heat utilization exhaust duct without being led to a heat exchanger, and hot air passing through the exhaust heat recovery exhaust duct is transferred to the sensible heat exchanger And controlling the exhaust heat recovery exhaust direction switching valve so as to lead to the exhaust heat recovery utilization method of the hot air ventilation dryer with sensible heat exchanger.

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