JP4516704B2 - Superheated steam drying method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a superheated steam drying method and apparatus for drying cloth such as clothing and towels.
[0002]
[Prior art]
As shown in FIG. 3, the conventional dryer takes in fresh air from the outside with a blower fan 31, heats it with a heater 32, and sends it to a drying drum 33. The drying drum 33 dries by contacting the heated air while stirring the clothes 20 containing moisture, the linen, the towel, and the like. The air that has dried clothes and the like passes through the exhaust duct 34, passes through the lint removal filter 35, and is discharged outside. In FIG. 3, the blower fan 31 is provided on the inlet side where air flows into the drying drum 33, and is generally called a push-in type. On the other hand, in FIG. 4, the blower fan 31 is provided on the outlet side with respect to the drying drum 33 and is generally called a suction type. Both the push-in type and the suction type are hot air supply methods in which fresh air from the outside is heated and brought into contact with the object to be dried 20 and then exhausted to the outside. Currently, it is used in many dryers. ing.
[0003]
However, in the one-way hot air supply method in which fresh air heated in this way is discharged to the outside after passing through the drying drum 33, the contact efficiency with the object to be dried 20 is low, and thus the heated air May be discharged to the outside through the exhaust duct 34 without being in contact with the object to be dried 20, and the disadvantage is that the heat loss is large. In such a one-way supply method, there is a report that the amount of heat actually heated by the air is about twice as much as the amount of heat necessary for drying the moisture in the object to be dried 20. Therefore, development of a method for improving the thermal efficiency and drying an object to be dried with energy saving is desired.
In addition, such a one-way supply method requires the installation of a large-diameter exhaust duct, so that there is a problem that the cost of installing the device is high as the device itself becomes large. Furthermore, since the exhaust gas is released outdoors, there is also a problem that off-flavors are also emitted outdoors.
In view of such circumstances, a method for drying wet fabric using dry superheated steam as described in JP-A-61-73699 has been described. In this method, fabric is taken in and out. Each time the steam in the drying comes out, the efficiency is poor.
[0004]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a drum-type drying method and an apparatus thereof that can improve energy efficiency and save energy, and do not discharge an odor to the outdoors because an exhaust duct is not employed.
[0005]
[Means for Solving the Problems]
The superheated steam type drying method according to the present invention is a drum-type dryer that uses a superheated steam to dry a moisture-containing fabric, which is an object to be dried, in a main constituent path including a drying drum and a circulation duct. While supplying steam, the air from the beginning in the main component path is guided to the air storing means outside the main component path, and the main component path is closed circuit, and then superheated steam is generated in the main component path. It is characterized by evaporating the moisture of the material to be dried by circulation.
As the superheated steam, superheated steam having a temperature range of 100 ° C to 150 ° C can be used.
Also, the moisture in the material to be dried evaporates to increase the pressure in the main component path, but the steam corresponding to the increase in the internal pressure is cooled and collected as condensed water, and the exhaust gas is not released outdoors. Can be.
[0006]
With such a configuration, since the superheated steam circulates and contacts the object to be dried, the heat loss of being discharged outside without contacting the object to be dried becomes substantially zero, greatly improving the thermal efficiency and saving energy. be able to. Moreover, since the water | vapor evaporated from a to-be-dried object is collect | recovered as condensed water, without employ | adopting an exhaust duct, it can prevent the off-air exhaust with a strange odor. Furthermore, since drying is performed at a temperature of 100 ° C. or higher and the temperature of the object to be dried itself is 100 ° C. or higher at the end of drying, it can have a sufficient sterilizing effect that can be used for drying hospital linens and the like.
[0007]
Further, the superheated steam drying apparatus according to the present invention is installed in a drying drum that stirs a fabric containing moisture, which is an object to be dried, a circulation duct that connects an outlet and an inlet of the drying drum, and the circulation duct. A circulation fan and a superheater; a steam supply pipe connected to the circulation duct; a bypass pipe connecting one position of the circulation duct to another position so as to bypass a part of the circulation duct; and provided in the bypass pipe Air drying means such as an air bag for retaining the air in the drying drum and the circulation duct, and a cooling condenser provided in the bypass pipe or the circulation duct. The main constituent path including the drum and the circulation duct is a closed circuit.
The superheated steam dryer can be used in a drum-type laundry dryer.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a block diagram showing an outline of a superheated steam dryer according to an embodiment of the present invention. As shown in FIG. 1, the superheated steam type drying apparatus according to the present invention includes a drying drum 1 for tumbling (stirring) an object to be dried 20 such as clothes containing moisture, linen, towels, etc. The drying drum 1 is provided with a door 2 on the front side for feeding an object to be dried 20 into the drum 1. The drying drum 1 has a hole in its outer peripheral surface to allow air and steam to pass through. The drying drum 1 can also be used as a washing drum in the case of a combined washing and drying machine. The door 2 has a seal attached to the outer periphery so that the inside of the drying drum 1 can be sealed.
[0009]
Further, the outlet and the inlet of the drying drum 1 are connected by a circulation duct 3, and the drying drum 1 and the circulation duct 3 are referred to as a main constituent path in the present invention. As shown in FIG. 1, the outlet of the drying drum 1 is provided in the upper part of the drying drum 1, but can also be provided in the lower part. In the case of a single machine only for drying, it is preferable to provide an outlet at the lower part because the steam contains evaporated water from the material to be dried 20 and the specific gravity becomes heavy. On the other hand, in the case of a combined washing and drying machine, since the lower part has facilities such as washing drainage, the outlet is preferably provided in the upper part. The inlet of the drying drum 1 may be in the upper part or the lower part of the drying drum 1.
[0010]
The circulation duct 3 supplies a circulation fan 4 for creating a circulation flow in the main component path, a superheater 5 for heating the circulation steam in the main component path to superheated steam, and steam in the main component path. And a steam supply pipe 6 for the purpose.
The circulation fan 4 may be installed at any position in the circulation duct 3. However, in order to efficiently suck the air and steam in the drying drum 1 into the circulation duct 3, the circulation fan 4 is installed in the vicinity of the outlet of the drying drum 1. preferable. The circulation fan 4 is driven by an electric motor or the like.
The superheater 5 may be installed at any position in the circulation duct 3. However, in order to supply the superheated water vapor into the drying drum 1 so as to reduce heat loss, the superheater 5 is installed near the inlet of the drying drum 1. preferable. Moreover, the thing of the performance which can raise a vapor | steam to the temperature of 100 to 150 degreeC is enough for the superheater 5.
The steam supply pipe 6 may be installed at any position in the circulation duct 3, but by supplying water vapor, the air that was initially in the main component path is removed from the check valve 11 by air temporarily storing means. In order to expel it to a certain airbag 14, it is preferable to install it on the opposite side of the check valve 11 with the drying drum 1 in between. Further, the steam supply pipe 6 is provided with a steam supply valve 7 in the vicinity of a position where it is connected to the circulation duct 3, and the other is connected to a steam supply source (not shown).
[0011]
Two points of one position of the circulation duct 3 and another position are connected by a bypass pipe 10 so as to bypass a part of the circulation duct 3. The position of the two points connecting the circulation duct 3 and the bypass pipe 10 is not particularly limited, but one point drives out the initial air in the main component path from the check valve 11, so that there is a gap between the drying drum 1 and the circulation fan 4. The other point is preferable, and the other point is preferably the top (vertical) position between the circulation fan 4 and the superheater heater 5 in order to efficiently send air to the main constituent path after completion of drying.
The bypass pipe 10 includes, in order from the upstream side, a check valve 11 for opening and closing the valve by pressure, a condenser 12 for cooling and condensing steam, and an automatic valve A13 for automatically opening and closing the valve. An air bag 14 for temporarily holding the air in the main component path, an air supply blower 15 for sending the air held in the airbag 14 again into the main component path, and automatically And an automatic valve B16 for opening and closing the valve.
[0012]
The check valve 11 is not particularly limited as long as the valve body operates so as to prevent the backflow of steam from the condenser 12 or the bypass 14 to the main component path. For example, the check valve 11 is a lift check valve or a swing check valve. A valve or a ball check valve can be used. Further, instead of the check valve 11, for example, a thin tube can be provided between the circulation duct 3 and the condenser 12, or a valve that opens and closes depending on the value of a hygrometer provided in the circulation duct 3 can be provided. .
The air bag 14 needs a volume capable of temporarily retaining air from the beginning in the main component path, and the size can be appropriately designed according to the size of the drying drum 1. For example, it can be set to about 0.5 m ³ . A resin container or a stretchable resin bag can be used.
[0013]
According to such a configuration, in the case of a single drying machine, after an object to be dried 20 containing water that has been washed is put into the drying drum 1 from the separate washing machine and the door 2 is closed, or after washing and drying. In the case of the dual-purpose machine, after the washing process is completed, the circulation fan 4 and the superheater heater 5 are started, and the steam supply valve 7 is opened to supply steam from the steam supply pipe 6 into the main component path. At this time, the automatic valve A13 is opened, the automatic valve B16 is closed, and the blower blower 15 is stopped. When steam is supplied, the air that was originally in the main component path is expelled from the check valve 11 to the bypass pipe 10. Water in the air is cooled and condensed by the condenser 12, but the other air is expelled to the airbag 14 via the automatic valve A13 and temporarily held there.
[0014]
After the initial air in the main component path is held in the airbag 14, the steam supply valve 7 is closed to stop the supply of water vapor, and the automatic valve A13 is also closed. Thereby, the inside of the main component path is a closed circuit from which air is removed. The circulating steam in the main constituent path having a temperature of about 100 ° C. is heated to a temperature range of 100 ° C. to 150 ° C., preferably 120 to 130 ° C., and superheated by the superheater 5. When the superheated steam is near 100 ° C., it takes time to evaporate the moisture contained in the material 20 to be dried, which is not preferable. In general, the temperature of the superheated steam is 120 ° C. or higher. On the other hand, if the temperature exceeds 150 ° C., the object to be dried 20 may be discolored due to heat, which requires attention and is not preferable.
[0015]
The moisture contained in the material to be dried 20 in the temperature drying drum 1 is evaporated by this superheated steam, and the material to be dried 20 is dried. When the evaporation of moisture in the object to be dried 20 starts vigorously, an internal pressure rise comparable to the evaporated moisture occurs in the main constituent path. This increase in internal pressure opens the check valve 11, and steam containing evaporated water is introduced into the condenser 12 through the bypass pipe 10. The condenser 12 cools and condenses (liquefies) the steam, and discharges condensed water to a collection container or the like (not shown).
[0016]
After drying the object to be dried 20, the operation of the circulation fan 4 and the superheater heater 5 is stopped. Then, by opening the automatic valve B16 and starting the air supply blower 15, the air temporarily held in the airbag 14 is supplied again to the main component path. At this time, the automatic valve A13 remains closed. Therefore, the steam remaining in the main component path passes through the check valve and is introduced into the condenser 12 through the bypass pipe 10. The condenser 12 cools and condenses the steam as in the drying process, and discharges it as condensed water.
After the resupply of air is completed, the automatic valve B16 is closed. Then, the door 2 is opened and the dried material 20 to be dried in the drying drum 1 is taken out.
[0017]
Here, as shown in FIG. 2, a thin tube may be provided between the circulation duct 3 and the condenser 12 instead of the check valve 11. Thus, the evaporated water in the main component path can be positively cooled and removed by the condenser 12 without waiting for the internal pressure to rise, so that the object to be dried is more than that when the check valve 11 is provided. 20 can be dried quickly. However, in order to cool more than the increase in internal pressure, it is necessary to overheat with the superheater 5 as compared with the case where the check valve 11 is provided, and the thermal efficiency is deteriorated.
A valve that opens and closes according to the value of a hygrometer provided in the circulation duct 3 can be provided at the inlet of the thin tube. Thereby, the evaporating water in the main component path can be cooled and removed by the capacitor 12 by adjusting the humidity without waiting for the internal pressure to rise, so that the object to be dried 20 can be quickly dried. However, in order to perform cooling that is equal to or greater than the increase in internal pressure, it is necessary to further heat with the superheater 5 as described above, resulting in poor thermal efficiency.
Furthermore, although the capacitor 12 is provided in the bypass pipe 10, it can also be provided in the circulation duct 3. As a result, the evaporated water in the main configuration path can be cooled and removed, so that the object to be dried 20 can be dried faster than the case where it is provided in the bypass pipe 10. However, since cooling is performed in the main configuration path, it is necessary to heat the superheater 5 more than in the case where the bypass pipe 10 is provided, and the thermal efficiency is deteriorated.
[0018]
【The invention's effect】
As described above, according to the present invention, since the main configuration path forms a closed circuit, the superheated steam circulates and comes into contact with the object to be dried, so that the heat is discharged outside without contacting the object to be dried. Loss is almost zero. Heat release to the outside of the main component path is only the increase in internal pressure due to moisture evaporation from the object to be dried.Therefore, the amount of heat required for drying the object to be dried is slightly reduced due to heat dissipation of the device, but almost no residual moisture. As compared with the conventional one-way hot air supply method, the thermal efficiency is greatly improved, and 40-50% of energy can be saved compared to the conventional one.
[0019]
In addition, according to the present invention, it is possible to eliminate the need for exhaust to the outdoors by temporarily storing the initial air in the main component path in the airbag. Further, since the evaporated water from the object to be dried is cooled by the condenser and collected as condensed water, the off-flavor component can be taken into the condensed water. Therefore, it is possible to substantially eliminate the need for exhaust to the outdoors, and to prevent the outflow of a strange odor to the inside and outside of the room. In addition, since the initial air in the main component path is excluded, the object to be dried is not oxidized by oxygen during drying, and the clothes can be dried easily.
[0020]
Therefore, according to the present invention, it is possible to provide a superheated steam drying method and apparatus that can improve the thermal efficiency and save energy, and that do not discharge an off-flavor to the outdoors because an exhaust duct is not used.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an outline of a superheated steam dryer according to the present invention.
FIG. 2 is a configuration diagram showing an alternative example of the superheated steam dryer according to the present invention.
FIG. 3 is a configuration diagram showing an outline of a conventional push-in drum type drying apparatus.
FIG. 4 is a configuration diagram showing an outline of a conventional suction-type drum-type drying apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Drying drum 2 Door 3 Circulation duct 4 Circulation fan 5 Superheater heater 6 Steam supply pipe 7 Steam supply valve 10 Bypass pipe 11 Check valve 12 Capacitor 13 Automatic valve A
14 Airbag 15 Air supply blower 16 Automatic valve B
20 Dried object 31 Air supply fan 32 Heater 33 Drying drum 34 Exhaust duct 35 Waste thread removal filter

Claims (5)

In a drum dryer for drying an object to be dried, while supplying steam to a main constituent path including a drying drum and a circulation duct, air from the beginning in the main constituent path is removed from the main constituent path. A superheated steam type drying method characterized by evaporating moisture of the material to be dried by circulating the superheated steam in the main constituent path after guiding the air to the air storage means and making the main constituent path into a closed circuit. The superheated steam drying method according to claim 1, wherein the superheated steam is in a temperature range of 100C to 150C. Although the pressure in the main component path rises due to the evaporation of the moisture of the material to be dried, the steam of only the increase in the internal pressure is cooled and recovered as condensed water, and the exhaust gas is not released outdoors. The superheated steam drying method according to claim 1 or 2. A drying drum that stirs the material to be dried, a circulation duct that connects an outlet and an inlet of the drying drum, a circulation fan and a superheater installed in the circulation duct, a steam supply pipe connected to the circulation duct, A bypass pipe connecting one position of the circulation duct to another position so as to bypass a part of the circulation duct, the drying drum provided in the bypass pipe, and an air storage means for retaining air in the circulation duct And a condenser for cooling provided in the bypass pipe or the circulation duct, and the main constituent path including the drying drum and the circulation duct is a closed circuit, Type drying equipment. A drum-type washing and drying apparatus comprising the superheated steam drying apparatus according to claim 4.

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