JPH0558359B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Industrial Application Field The present invention relates to a clothes dryer that safely dries clothes washed with petroleum-based solvents at low temperatures and recovers the solvents in the clothes. .

(b) Conventional technology When drying clothes that have been washed using petroleum-based solvents, since the flash point temperature of the solvent is as low as approximately 42°C,
Solvent gas concentration and drying air temperature must be monitored. For example, in the clothes dryer disclosed in Japanese Utility Model Application Publication No. 59-190192, when the gas concentration increases, the circulating drying air is exhausted and outside air is sucked in. Even in each type of dryer, air intake and exhaust air is adjusted according to the temperature rise, the passage of time, etc.

However, since this releases solvent gas, it is almost impossible to recover it, and even though petroleum-based solvents are cheap, they are wasteful and there are concerns about air pollution.

Therefore, it has been proposed to carry out the drying operation at a temperature of the drying air at a low temperature that does not pose a risk of ignition, for example, at a temperature of 40° C. or lower, and to recover the solvent (see Japanese Utility Model Application Publication No. 196187/1987).

(c) Problems to be solved by the invention When recovering petroleum-based solvents, it is necessary to strictly control the temperature of the drying air for safety reasons, and a thermometer is additionally provided to stop the system when the temperature exceeds the control temperature. There is a need. This thermostat is the last safety valve, and failure of this thermostat is completely unacceptable.

However, in reality, as it is a component, it may break down, and conventional countermeasures have been to install multiple similar thermoses, and to complicate the electrical circuit so that drying operation cannot be performed in the event that a thermos breaks down. It was carefully crafted.

The present invention constantly checks the operating status of these thermos and stops the drying operation if a failure is detected, without providing multiple thermos as safety valves or complicating the circuit. It is something.

(d) Means for Solving the Problems The solution according to the present invention is to store clothes washed with a petroleum solvent in a drying room, and blow drying air controlled at a low temperature below the flash point temperature of the solvent. A clothes dryer that sequentially performs a low-temperature drying operation that supplies drying air to a drying chamber and a high-temperature drying operation that controls drying air at a high temperature. a low-temperature overheating thermostat that operates at a predetermined or higher drying temperature than the drying temperature during the high-temperature drying operation; a drying control that executes the low-temperature drying operation and the high-temperature drying; The configuration includes a safety control section that stops operation when the thermostat is not activated.

(e) Action The low temperature overheating thermostat does not operate while the low temperature drying operation is normally controlled, but operates while the high temperature drying operation is normally controlled. Therefore, the safety control unit checks whether the low-temperature overheating thermostat is operating normally during high-temperature drying operation, and if it is not operating, it detects it and puts it into safe operation, and if necessary, displays a malfunction of the thermostat. Informs you that the next low temperature drying operation will be unsafe.

(F) Embodiment To explain based on the drawings, the dryer body 1 is divided into two upper and lower stages, with the upper stage comprising a drying chamber 3 having a rotating drum 2, and the lower stage comprising a U-shaped passage. A recovery tank 4 is configured. At the upper front of the body 1, there is provided an entrance/exit for the drying room 3 which is opened and closed by a door (not shown), and the rotating state of the drum 2 can be visually observed through the see-through window of the door. Further, the upper part of the body 1 constitutes an operation room 5 in which an operating body and a control circuit for operating and controlling the dryer are incorporated. Outlet 6 of drying chamber 3
and one end of the recovery tank 4 are connected, and the inlet 7 and the other end of the tank are connected.

A filter 8 and a cooler 9 are sequentially arranged on the outlet 6 side of the recovery tank 4, and the inner bottom of the recovery tank 4 is formed into a storage chamber 10 for the condensed solvent. A fan 11 made of aluminum fins is provided near the inner bottom of the collection tank 4 on the inlet 7 side, and a heater 12 is provided near the inlet 7. A cover 13 made of a punched plate is placed on the top of the storage chamber 10.

As shown in Fig. 2, the rotating drum 2 has a front half facing the inlet side and a rear half facing the outlet, the outer periphery of which is airtightly partitioned, and only the front side of the front half is dry. A group of air intake ports is provided, and a group of dry air outlet ports is provided on the entire surface of the rear half. That is, a group of suction ports communicates with the inlet 7, and a group of discharge ports communicates with the outlet 6. Clothes washed with a petroleum solvent are loaded into the rotating drum 2 from the clothes entrance on the front end. It is designed to provide an air flow of ~30m ³ /min.

The cooler 9 and the heater 12 are of the Finch-Ube type, and the cooler 9 is supplied with cooling water through a manual or automatic cold water valve 14, and the heater 12 is supplied with steam through an inlet valve 15 and an outlet valve 16, respectively. Ru.

A torque motor is installed near the outlet 6 of the drying chamber 3.
An exhaust port 20 is provided with an exhaust cover 19 that is opened and closed by M ₁ and M ₂ 17 and 18, and is located downstream of the fan 11 of the recovery tank 4 and is always biased by a spring in the closing direction. and an intake port 2 equipped with a lid (not shown) that is opened and operated by a torque motor M ₃ 21.
2 is provided. This exhaust port 20 and intake port 22
is closed during low temperature drying operation.

A pressure adjustment port 23 that passes through the operation chamber 5 and communicates with the outside is formed on the top surface of the drying chamber 3. This adjustment port 23 is preferably communicated with the outside through a duct or the like so as not to affect the electrical components inside the operation chamber 5, and is normally closed by a spring-loaded adjustment lid 24. . The weight of the lid also acts on this closing.

A drainage path 25 from the storage chamber 10 is connected to a storage tank 26
The stored solvent is connected to the float 2.
The recovery pump 29 responds to the operation of the float switches 28 as the solvent 7 rises, and the solvent is sent to an appropriate solvent tank (not shown).

A first temperature detection element 30 for detecting the inlet temperature of the drying air is disposed on the inlet 7 side of the drying chamber 3, and a second temperature detection element 31 for detecting the outlet temperature is disposed near the outlet 6. , a third temperature detection element 32 is disposed downstream of the cooler 9 to detect the cooling temperature. These sensing elements are thermistors.

In the vicinity of the outlet 6 in the collection tank 4, a low temperature overheating thermostat 33 consisting of a thermistor is disposed for ultimate protection against the risk of ignition. By the way, if this thermostat 33 is replaced with a normal thermostat and operates during low-temperature drying operation, it will immediately cut off the power, and if it operates during any other operation, it will simply send an activation signal without cutting off the power. The circuit may be configured so that it can output.

When the adjustment lid 24 is opened, the release switch 34 is activated. A pair of adjacent magnets 3 are mounted on the rotating drum 2.
A magnet 37 is attached at a predetermined angle from 5 and 36, and when the drum 2 rotates, these magnets 3
5, 36, and 37 are detected by a magnetic sensor 38 (for example, a reed switch). This detection signal is processed and used to determine the rotational direction of the rotating drum 2 and the fan 11.

As shown in FIG. 3, the control circuit in the operation room 5 is assembled around a microcomputer (hereinafter referred to as microcomputer) 39 consisting of a CPU, ROM, RAM, and F/O. The entire drying operation is automatically controlled by operation. Although everything can be manually controlled by the user, the explanation of this point will be omitted. The rotating drum 2 and the fan 11, which are driving means, have their respective wires connected in advance and are connected to a three-phase 200V power source at the place of use according to color. The microcomputer 39 controls the rotating drum 2 and the fan 11.
Controlling the drive of the motor means providing a drive signal and a stop signal.

The microcomputer 39 has a float switch 28, a first
~Third temperature detection element 30, 31, 32, low temperature overheating thermostat 33, open switch 34, magnetic sensor 3
Input from 8, rotating drum 2, fan 11, cold water valve 14 (in case of automatic), inlet valve 15, outlet valve 16,
Each torque motor M ₁ , M ₂ , M ₃ 17, 18, 21,
It outputs to the recovery pump 29, various indicators 41, and buzzer 42. The microcomputer 39 includes a pre-start control section 43, a drying control section 47, a low temperature operation counter 48, a high temperature operation counter 49, and a safety control section 50 for automatic control.

As shown in FIG. 4, first, when the power is turned on, temperature measurement is started, and the pre-start control unit 43 checks whether the temperature at the inlet 7 is above the flash point temperature (for example, 50° C. or above). . If the cool down was omitted last time, the inside of the drying chamber 3 may remain at a high temperature, and if the temperature exceeds the flash point, the inlet valve 15
and output a closing signal to the outlet valve 16 just in case,
The temperature abnormality is indicated by the display 41, and _{the intake} and exhaust ports 20,
22 and drive the drum 2 and fan 11 for 10 seconds. Then, the buzzer 42 notifies the abnormality for a predetermined period of time, and the output is stopped while the abnormality display remains. If this happens, turn off the power and
The power will be turned on again when it restarts.

If the temperature is lower than the flash point, press the start key 40.
With this operation, the negative phase detection control unit 44 checks whether the drum 2 and fan 11 are properly connected to the three-phase power source. This is a work that is incorporated as part of the drying operation, and a torque motor and a spring are used for suction and exhaust ports 20 and 2.
2 is closed, the drum 2 and fan 11 are driven, and the cold water valve 14 is opened.

Thus, if the inlet temperature is appropriate, the drying control section 47 opens the inlet valve 15 and the outlet valve 16, and also sets the low temperature drying operation time and the subsequent high temperature drying operation time based on the outlet temperature of the cooler 9, which depends on the cooling temperature. The drying operation time is set in a low temperature operation counter 48 and a high temperature operation counter 49, respectively. First, the low temperature operation counter 48 counts down.

When the solvent is stored in the storage tank 26 and reaches a predetermined level, the float switch 28 inputs a liquid level signal based on the rise of the float 27, thereby driving the recovery pump 29.

When the pressure inside the drying chamber 3 rises abnormally due to an explosion or the like, the adjustment lid 24 is pushed up and the adjustment port 23 is opened to automatically release the pressure, and the open switch 34 is activated in response to the lid opening operation. When activated, the state changes to output stop state.

During normal operation, the outlet valve 16 is opened or closed depending on whether the measured temperature of the dry air at the inlet 7 is below the lower limit or above the upper limit of the first control temperature, which is lower than the flash point temperature. Then, the inlet valve 15 is opened and closed depending on the temperature measured at the inlet 7 and the outlet 6, but this opening/closing operation is performed with priority given to the temperature measured at the outlet 6. The upper and lower limits of the second control temperature of the inlet valve 15 at the outlet 6 are approximately the same as the upper and lower limits of the first control temperature of the outlet valve 16 at the inlet 7, and are the upper and lower limits of the control temperature of the inlet valve 15 at the inlet 7. is set to be about 3° C. higher than the upper and lower limits of the first control temperature of the outlet valve 16 at the inlet 7. The temperature difference between the upper and lower limits is approximately 1° C., and this is provided to prevent chattering during the opening and closing operations of the inlet valve 15 and outlet valve 16.

The low-temperature overheating thermostat 33 detects the temperature of the drying air at the outlet 6, and ultimately makes the system safe when the temperature detection elements 30, 31, and 32 are insufficiently controlled. That is, when the thermostat 33 detects a measured temperature slightly higher than the upper limit of the first control temperature of the inlet valve 15 at the outlet 6, it inputs an activation signal to the microcomputer 39 to stop the output, and also displays an abnormal temperature rise. - Execute notification.

During this low-temperature drying operation, the solvent in the clothes is contained in the drying air and condenses and liquefies in the cooler 9.
The liquid is then put into a storage tank 26 and recovered by a pump 29 to a suitable location, such as a solvent tank of a dry cleaner, via a water separator.

In this way, while the heater 12 is maintained at the first control temperature with little overshoot by the opening/closing control of the outlet valve 16, the low temperature operation counter 4
8 ends the count.

The drying control unit 47 uses the torque motors 18 and 21 to open the suction and exhaust ports 20 and 22, and closes the inlet valve in order to shift to high-temperature drying operation in which outside air is sucked in, heated, and discharged to the outside after drying. 15 is held open. And high temperature operation counter 4
9, the opening and closing of the outlet valve 16 is controlled so that the temperature measured at the inlet 7 corresponds to the upper and lower limits of the fourth control temperature, which is sufficiently high. The safety control unit 50 of the microcomputer 39 checks the input of the signal from the low temperature overheating thermostat 33 one minute after the transition. Normally, this thermostat 33 is quickly activated by a portion of the high-temperature dry air directed toward the exhaust port 20, and if it is not activated even by the high-temperature dry air, it is a failure. Therefore, if there is a failure, the safety during low-temperature drying operation cannot be checked, so the safety control unit 50
indicates a thermo error and output is stopped.

If the float switch 28 is already inactive during this high-temperature operation, the recovery pump 29 is stopped, but if recovery has not progressed (if the float switch 28 is still operating), the next process (e.g. deodorization, cooling The recovery pump 29 is stopped when the float switch 28 becomes inactive during the down cycle.

In this embodiment, the microcomputer 3 controls the low temperature drying operation time and the high temperature drying operation time depending on the temperature of the cooling water.
Although this is determined and executed by the comparison calculation in step 9, it can also be determined based on the amount of recovered solvent. That is, the recovery pump 29 is driven until the upper float switch 28 is activated and the lower float switch 28 is deactivated, and while this is repeated, the time during which the drive signal is output to the recovery pump 29 is controlled. Accumulated by a counter. Then, the solvent recovery time (operation time) corresponding to the rated load is calculated and memorized in advance through experiments, etc., and the low-temperature drying operation is ended when the integrated value (time) of the above counter matches this recovery time. . In this case, the high temperature drying operation time is determined based on the low temperature operation time or is set to a fixed time.

(G) Effects of the Invention According to the present invention, temperature abnormalities during low-temperature drying operation can be reliably detected by the low-temperature overheating thermostat and controlled safely. Also, the thermometer checks whether it is operating normally during high-temperature drying operation, and if it malfunctions, the drying operation is stopped.
There is no chance of causing a serious accident by driving without knowing about the malfunction. Moreover, in case this low temperature overheating thermostat fails, it is not necessary to provide a plurality of similar low temperature overheating thermostats or to have a complicated circuit configuration for checking.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of a clothes dryer according to the present invention, FIG. 2 is a side view of a rotating drum, FIG. 3 is a control circuit diagram, and FIG. 4 is a flowchart for explaining the operation. 3...Drying room, 4...Recovery tank, 9...Cooler, 11...Fan, 12...Heater, 30,3
1...Temperature detection element, 15...Inlet valve, 16...
Outlet valve, 47... Drying control section (means), 33...
Low temperature overheating thermostat, 50...Safety control section.

Claims (1)

[Claims] 1. A low-temperature drying operation in which clothes washed with a petroleum-based solvent are stored in a drying chamber, and drying air controlled at a low temperature below the flash point temperature of the solvent is supplied to the drying chamber, and a drying operation is controlled at a high temperature. with high temperature drying operation,
The clothes dryer is a clothes dryer that operates in sequence, and is located near the drying air outlet of the drying chamber, and operates at a temperature higher than a predetermined value than the drying temperature during the low-temperature drying operation, and at a drying temperature during the high-temperature operation. It is characterized by comprising a thermostat, a drying control unit that executes the low-temperature drying operation and the high-temperature drying operation, and a safety control unit that stops the operation when the low-temperature overheating thermostat is not activated during the high-temperature drying operation. Clothes dryer.