JP2902902B2 - Dryer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dryer for drying laundry washed with a solvent.

[0002]

2. Description of the Related Art In a conventional dryer disclosed in Japanese Patent Publication No. 3-58760 and the like, when drying laundry washed with a petroleum solvent, first, a circulation drying path is formed, and a heater and a drying chamber are formed. Then, drying is performed while circulating hot air in the order of the cooler to recover the solvent. When this is completed, an exhaust drying path is formed, and the hot air generated when the outside air hits the heater is guided to the drying chamber and thereafter discharged to the outside,
Further drying is performed.

[0003] Since such a control for drying is performed by a microcomputer, the microcomputer does not operate in the circulating drying path due to malfunction of the microcomputer, and the heater also operates. If left untreated, only evaporation of the solvent will proceed without solvent recovery. Then, the concentration of the solvent gas increases and becomes equal to or higher than the lower explosive limit concentration (usually 0.6%) of the petroleum-based solvent, which may cause an explosion.

In view of this, a configuration is conceivable in which a temperature switch that operates when the temperature rises in such a case is separately provided, and based on the operation of the temperature switch, the operation of the heater is stopped independently of the microcomputer. .
However, even if the operation of the heater is stopped, the concentration of the solvent gas does not immediately decrease, so that the risk of explosion is not completely eliminated.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a microcomputer for controlling a drying operation which malfunctions, for example, when a cooling device stops operating and a heater keeps operating in a circulating drying path. An object of the present invention is to provide a dryer that can immediately eliminate the danger of explosion.

[0006]

SUMMARY OF THE INVENTION A dryer according to the present invention includes a dryer main body, a drying chamber disposed in the dryer main body, for storing laundry washed with a solvent, a heater, and a heater. A blower that generates hot air for drying the laundry by blowing on the wind, and a cooler that cools the hot air after passing the laundry to collect a solvent evaporated from the laundry by the hot air, and the heater, A circulating drying path in which drying is performed while circulating hot air in the order of a drying chamber and a cooler while collecting the solvent, or hot air generated when the outside air is applied to the heater is guided to the drying chamber, and thereafter the outside of the main body of the dryer. Switching means for switching and forming an exhaust drying path for drying by discharging to the heater, a heater, a blower, a cooler, a microcomputer for controlling the driving of the switching means, A temperature switch that is activated when the hot air temperature reaches an abnormal temperature due to malfunction of the microcomputer, etc., and a control system of the microcomputer for the switching means is cut off based on the operation of the temperature switch, and the exhaust drying path by the switching means is switched off. And a maintenance means for maintaining the switching state.

[0007]

When drying by the circulation drying path, the microcomputer malfunctions, and the cooler stops operating while the circulation drying path remains and the heater keeps operating, so that the solvent gas concentration increases.

However, at this time, when the temperature of the hot air reaches the abnormal temperature and the temperature switch is operated, the control system of the microcomputer for the switching means is cut off based on this operation, and the switching means switches the exhaust drying path. . Therefore, the solvent gas is immediately discharged to the outside, and the concentration of the solvent gas decreases. Due to the decrease in the concentration of the solvent gas, the danger of explosion is immediately eliminated.

Further, since the switching state is maintained, even if the temperature of the hot air is temporarily lowered and the temperature switch is restored, the discharge of the solvent gas is not interrupted.

[0010]

1 and 2 show the configuration of a commercial dryer according to an embodiment of the present invention. 1 is a dryer main body, 2 is this dryer main body 1
A drying chamber 3 formed therein is a rotating drum rotatably disposed in the drying chamber 2, and laundry washed with a petroleum-based solvent is put into the rotating drum 3. The rotary drum 3 has a cylindrical shape and has a large number of ventilation holes in a peripheral wall. 4
Is a drum motor for driving the rotary drum 3.

Reference numeral 5 denotes an intake port provided on the upper part of the dryer main body 1, and reference numeral 6 denotes a heater connected to a lower side of the intake port 5. The heater 6 includes a steam pipe 9 having steam valves 7 and 8 and connected to a steam generation source (not shown). 10 is an introduction path connecting the heater 6 and the drying chamber 2;
Is a discharge passage connected to the lower portion of the drying chamber 2, 12 is a blower connected to the discharge passage 11, and 13 is a blower 12
A communication path connected to the rear side of the dryer main body 1;
Reference numeral 14 denotes an end of the communication path 13 and an exhaust port provided at an upper portion of the main body 1 of the dryer.

Reference numeral 15 denotes a circulation path provided at the upper part of the dryer main body 1 so as to connect the heater 6 with the vicinity near the upper side of the communication path 13, and reference numeral 16 denotes a cooler arranged in the circulation path 15. . The cooler 16 has a cooling valve 17 and the refrigerator 1
The cooling pipe 19 is connected to the cooling pipe 19. Reference numeral 20 denotes a switching means, that is, a switching valve which selectively moves to a solid line position for closing the intake port 5 or a dashed line position for opening. It is usually at the position of the dashed line.

The movement of the switching valve 20 to the position indicated by the solid line means that the circulation drying path is switched. That is, when the steam valves 7 and 8 are opened, steam flows through the steam pipe 9 to operate the heater 6, and when the cooling valve 17 is opened, refrigerant flows through the cooling pipe 19 and the cooler 16 is opened. When the blower 12 is driven in the operating state, the air blows from the circulation path 15 to the heater 6 to generate hot air. The hot air is guided by the introduction path 10 and enters the drying chamber 2 to dry the laundry in the rotating drum 3. The solvent evaporates from the laundry by this drying, and the hot air contains the solvent gas. On the other hand, hot air is deprived of heat. Thereafter, the hot air passes through the discharge path 11, the blower 12, and the communication path 13 and reaches near the upper portion of the communication path 13. At this point, the hot air is drawn into the circulation path 15 under the influence of the flow of air from the circulation path 15 to the heater 6. Then, the hot air is actively cooled by the cooler 16, and the solvent gas is condensed to recover the solvent. Thus, the heater 6, the drying chamber 2,
The hot air circulates in the order of the cooler 16 and the solvent is collected and dried. In the drawing, solid arrows indicate the flow of hot air at this time.

On the other hand, the movement of the switching valve 20 to the position indicated by the one-dot chain line means that the exhaust drying path is switched.
That is, when the blower 12 is driven in a state where the heater 6 operates in the same manner, the outside air is positively sucked from the intake port 5, and the wind from the outside air hits the heater 6 to generate hot air. . The hot air similarly enters the drying chamber 2 to dry the laundry and contains the solvent gas. On the other hand, hot air is deprived of heat. Thereafter, the hot air is supplied to the discharge path 11, the blower 1
2 and through the communication path 13 to reach near the upper part of the communication path 13. In this case, the hot air is not drawn into the circulation path 15 because there is no flow of air from the circulation path 15 to the heater 6, and is directly discharged to the outside from the exhaust port 14. In the drawing, broken arrows indicate the flow of hot air at this time.

Reference numeral 21 denotes a hot air temperature sensor which is disposed downstream of the heater 6 in the introduction path 10 and detects the temperature of hot air introduced into the drying chamber 2. Reference numeral 22 denotes an exhaust gas temperature sensor that is disposed in the discharge path 11 and detects the temperature of hot air whose heat has been removed by drying. 23 is disposed downstream of the cooler 16 and in the circulation path 15,
It is a cooling temperature sensor that detects the temperature of hot air after cooling.
Each of these sensors 21, 22, and 23 is composed of a thermistor. Reference numeral 24 denotes a temperature switch having a contact, which is disposed at substantially the same location as the hot air temperature sensor 21. The temperature switch 24 operates and turns off when the hot air temperature reaches an abnormal temperature during drying by the circulation drying path.

FIG. 3 shows the circuit of the dryer. Reference numeral 25 denotes a microcomputer for controlling the dryer. Around the microcomputer 25, the steam valve 7,
8, cooling valve 17, blower 12, drum motor 4, switching valve 20, hot air temperature sensor 21, exhaust temperature sensor 2
2. There is a cooling temperature sensor 23 and a temperature switch 24.

As other peripheral parts, 26 is a key operation section for setting operation information and the like, 27 is an electromagnetic switch for a blower for driving the blower 12, and 28 is a normally open type which is turned on when the switch 27 is driven. A switch switch, 29 is a first relay coil, 30, 31 are normally open first relay switches that are turned on by driving the first relay coil 29, and 32 is a second relay switch.
The relay coil 33 is a normally closed second relay switch that is turned off by driving the second relay coil 32. The first relay coil 29 includes a first relay switch 30,
The power supply is connected to the power supply via the temperature switch 24 and the switch 28, and is connected to the power supply via the second relay switch 33. The switching valve 20 is connected via a first relay switch 31 to an output port P of the microcomputer 25 to which the second relay coil 32 is connected. Reference numerals 34 and 35 denote normally-closed first and second relays which are turned off by driving the first and second relay coils 29 and 32, respectively.
In the second relay switch, the microcomputer 25 checks whether the first and second relay coils 29 and 32 are normal by using these relay switches.

Next, the operation of the dryer will be described. When the operation information is set by the key operation unit 26 and the drying operation start operation is performed, the microcomputer 25 drives the drum motor 4 to start the rotation of the rotary drum 3 and drives the electromagnetic switch 27. To start driving the blower 12. When the electromagnetic switch 27 is driven, the switch 2
8 turns on. In addition, the steam valves 7 and 8 are opened and closed to control the drive of the heater 6 so that the detected temperature difference between the hot air temperature sensor 21 and the exhaust temperature sensor 22 is maintained at a predetermined value. Drive control of the cooler 16 is also started by opening and closing the cooling valve 17 so that the temperature detected by the cooling temperature sensor 23 is maintained at a predetermined value.

On the other hand, since the second relay switch 33 is normally closed and turned on, the first relay coil 2 is turned on.
9 is driven, the first relay switches 30 and 31 are on, and the first relay switch 34 is off. When the first relay switch 30 is turned on, the switch 28 is turned on, and the temperature switch 24 is turned on, the first relay coil 29 is driven even when the second relay switch 33 is turned off. .

In such a state, the microcomputer 25 outputs a predetermined output from the output port P. Then, the second relay coil 32 is driven, and the second relay switches 33 and 35 are turned off. Second relay switch 33
Is turned off, the first relay coil 29 is driven as described above. When the first relay switch 31 is turned on, the switching valve 2 is switched based on the predetermined output.
0 is driven, the switching valve 20 moves to the solid line position, and the circulation drying path is switched. Thereby, as described above, the solvent is recovered while the hot air is circulated, and drying is performed.

In this case, the heater 6 is controlled so that the temperature of the hot air to which the temperature switch 24 is exposed is maintained at a predetermined temperature difference between the hot air temperature sensor 21 and the exhaust air temperature sensor 22. By having, for example, 62-7
It is maintained at 2 ° C., and is kept below the operating temperature of the temperature switch 24. Therefore, the temperature switch 24 remains on.

When the drying in the circulation drying path is completed, the microcomputer 25 stops the predetermined output from the output port P. Then, the drive of the switching valve 20 is stopped, the switching valve 20 moves to the dashed-dotted line position, and the exhaust drying path is switched. Thereby, the hot air is generated by the suction of the outside air, and drying is performed, and the hot air is thereafter discharged to the outside.

In this case, the temperature of the hot air to which the temperature switch 24 is exposed is maintained at, for example, 80 to 90 ° C. because the predetermined value with respect to the detected temperature difference becomes large. Beyond. Then
The temperature switch 24 operates and turns off when the hot air temperature reaches the abnormal temperature. However, even if the first relay coil 29 is stopped and the first relay switch 31 is turned off based on this turning off, the driving of the switching valve 20 is stopped, so that there is no influence. Also, the output port P
, The second relay coil 32 stops driving, and the second relay switches 33 and 35 are turned on.

Immediately before the end of drying in the exhaust drying path, the microcomputer 25 closes the steam valves 7 and 8. Then, the hot air temperature decreases, and the temperature switch 24 returns to be turned on. When the drying is actually completed, the microcomputer 2 performs a cool-down operation.
5 again outputs a predetermined output from the output port P, and switches the switching valve 20 to the position indicated by the solid line. And the cooling valve 1
7 is opened to drive the cooler 16. Therefore, the cooling air circulates and rapid cool down is performed.

During the drying by the circulating drying path, the microcomputer 25 does not operate in the circulating drying path because the microcomputer 25 malfunctions or the sensors 21, 22, and 23 break down. When the heater 6 is kept operating, the solvent gas concentration in the drying chamber 2 increases.

However, at this time, the hot air temperature reaches an abnormal temperature, the temperature switch 24 operates and turns off, and based on this turning off, the first relay coil 29 stops driving (the second relay switch 33 is already turned off). It is off as you can see from the description above). Then, the first relay switch 3
0 and 31 are turned off and the first relay switch 34 is turned on. When the first relay switch 31 is turned off, the microcomputer 25 for the switching valve 20 is turned off.
Is cut off, the switching valve 20 moves to the dashed line position, and an exhaust drying path is formed. Therefore, the solvent gas is immediately discharged to the outside, and the concentration of the solvent gas decreases. The danger of explosion is eliminated by this decrease in the concentration of the solvent gas.

When the first relay switch 30 is turned off, the driving stop of the first relay coil 29 is maintained, and the formation of the exhaust drying path by the switching valve 20 is maintained.
Even if the temperature of the hot air is temporarily lowered and the temperature switch 24 is restored and turned on, the discharge of the solvent gas is not interrupted. Here, the first relay coil 29 and the first relay switches 30, 31 correspond to the maintaining means of the present invention.

[0028]

According to the present invention, when the microcomputer that performs the drying control malfunctions and the cooler stops operating while the circulating drying path remains, and the heater keeps operating, the hot air temperature increases. When the temperature reaches an abnormal temperature, the temperature switch is activated, the control system of the microcomputer for the switching means is cut off, and the exhaust drying path is switched by the switching means. It is possible to provide a highly safe dryer that can reduce the gas concentration and eliminate the danger of explosion.

Further, since the state of switching to the exhaust drying path is maintained, even if the temperature of the hot air is temporarily lowered and the temperature switch is returned, the discharge of the solvent gas is not interrupted, and The safety of the machine can be further enhanced.

[Brief description of the drawings]

FIG. 1 is a front view of a commercial drier according to an embodiment of the present invention.

FIG. 2 is a side view of the dryer.

FIG. 3 is a circuit diagram of the dryer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dryer main body 2 Drying room 3 Rotary drum 6 Heater 12 Blower 16 Cooler 20 Switching valve (switching means) 24 Temperature switch 25 Microcomputer 29 1st relay coil (maintenance means) 30, 31 1st relay switch (maintenance means) )

──────────────────────────────────────────────────続 き Continued on the front page (72) Yoshitaka Tsunomoto 2-18-18 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Masahiko Tsunoda 2-18 Keihanhondori, Moriguchi-shi, Osaka (56) References JP-A-4-236995 (JP, A) JP-A-4-279194 (JP, A) JP-A-63-288194 (JP, A) JP-A-6-296795 (JP, A) JP-A-6-15093 (JP, A) JP-A-5-277287 (JP, A) JP-A-63-183932 (JP, U) (58) Fields investigated (Int. Cl. ⁶⁾ , DB name) D06F 58/28 D06F 43/08

Claims (1)

(57) [Claims] 1. A dryer main body, a drying chamber disposed in the dryer main body, for storing laundry washed with a solvent, a heater, and a dryer for blowing the wind to dry the laundry. A blower that generates hot air, a cooler that cools the hot air after passing the laundry, and a heater that circulates the hot air in the order of the heater, the drying room, and the cooler in order to collect the solvent evaporated from the laundry by the hot air. A circulation drying path for drying while recovering the solvent, or an exhaust drying path for conducting drying by guiding hot air generated by the outside air hitting the heater to the drying chamber and then discharging the hot air outside the dryer body. A switching unit that switches and forms the heater, the blower, the cooler, and a microcomputer that controls the driving of the switching unit.
At the time of drying by the circulation drying path, a temperature switch that is activated when the temperature of the hot air reaches an abnormal temperature due to a malfunction of the microcomputer or the like, and a control system of the microcomputer for the switching means is cut off based on the operation of the temperature switch. A drier for switching the exhaust drying path by the switching means and maintaining the switching state.