JPH0696079B2 - Clothes dryer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention stores clothes washed with a petroleum solvent in a rotary drum, rotatably arranges the rotary drum, and an inlet of the drying chamber. The present invention also relates to a clothes dryer in which a collection tank having a cooler, a fan, and a heater installed therein is connected to the outlet.

(B) Prior Art This type of clothes dryer is disclosed in Japanese Utility Model Laid-Open No. 63-64393. This includes a drying chamber for drying clothes washed with a petroleum solvent, a condenser for condensing the solvent in the dry air exhausted from the drying chamber, a fan for circulating the dry air, and the condenser. And a temperature sensor that detects the temperature of the dry air that has passed through the condenser.

In the operation of such a configuration, first, the dry air heated by the heater is blown into the drying chamber to evaporate the solvent in the clothes, and then the dry air is cooled by the condenser to condense the solvent. When the drying operation is performed by repeating the blowing of the dry air that has passed through the condenser into the reheated drying chamber, and the temperature detected by the temperature sensor is equal to or higher than the specified value, that is, when the cooling capacity of the condenser is low. The drying operation time is extended for a certain period of time.

(C) Problems to be Solved by the Invention In the above conventional example, the temperature of the dry air supplied into the drying chamber, the temperature of the dry air that has passed through the condenser, and the solvent gas concentration are respectively as shown in FIG. There is a correlation.

That is, if the temperature of the dry air heated by the heater is constant, a large amount of solvent is condensed and separated from the dry air if the cooling capacity of the condenser is high, so the amount of solvent contained in the dry air supplied again to the drying chamber. Is low and the solvent gas concentration is low. However, if the cooling capacity of the condenser is low, the amount of solvent condensed from the dry air decreases, so the amount of solvent contained in the dry air increases and the dry air is supplied again to the drying chamber, so the solvent gas concentration is high. Become.

Also, if the cooling capacity of the condenser is kept constant, the amount of solvent that evaporates in the dry air will increase if the temperature of the dry air is high, but since the amount of solvent that is condensed is constant, the concentration of solvent gas in the drying chamber will increase. . However, when the temperature of the drying air becomes low, the amount of solvent that evaporates decreases, so the concentration of solvent gas in the drying chamber becomes low.

If the solvent gas concentration becomes too high, it may explode due to ignition such as static electricity. The lower limit of solvent gas concentration at which an explosion may occur is called the lower explosion limit concentration.

Regarding the cooling capacity of the condenser in the above-mentioned conventional example, for example, when city water is used as the refrigerant, the cooling capacity decreases because the water temperature of the city water is high in the summer. If the cooling capacity of this condenser decreases, the amount of solvent condensed will be less than the amount of solvent that evaporates in the dry air, and as a result, the concentration of solvent gas will increase, so the drying operation time will be extended and the concentration of solvent gas will be reduced. ing.

Thus, in the conventional method, the solvent gas concentration at the end of the drying operation becomes lower than the lower explosion limit concentration,
That is, the amount of the solvent contained in the drying air supplied into the drying chamber increases as the cooling capacity of the condenser decreases during the drying operation, and the concentration of the solvent gas in the drying chamber increases. If this tendency progresses, the explosion lower limit concentration may be exceeded temporarily, which is very dangerous.

Also, if the cooling capacity of the condenser is conversely high, a large amount of the solvent in the dry air can be condensed, so the amount of solvent contained in the dry air to be supplied to the drying chamber again will be small, and it will be considerably higher than the explosion lower limit gas concentration. Solvent gas concentration is low. Therefore,
By increasing the temperature of the dry air within the cooling capacity of the condenser to increase the amount of solvent that evaporates in the heating chamber, the drying time can be shortened, but the temperature of the dry air is controlled independently of the cooling capacity of the condenser. Then, extra dry operation time is spent.

The present invention solves such a problem.

(D) Means for Solving the Problem The solving means according to the present invention is a drying chamber for storing clothes washed with a petroleum solvent, an inlet and an outlet for dry air provided in the drying chamber, and the inlet and the outlet. And a fan for circulating the drying air between the drying chamber and the recovery tank, and a drying tank provided near the inlet in the recovery tank. A heater to heat the wind,
A cooler provided near the outlet for cooling the dry air to condense the solvent, a first temperature detector provided near the inlet for detecting the temperature of the dry air heated by the heater, and a cooler cooled by the cooler And a second temperature detector for detecting the temperature of the dry air, the solvent gas concentration in the drying chamber becomes lower than the explosion lower limit concentration in accordance with the change in the temperature detected by the second temperature detector. The control temperature setting unit that sets the control temperature and the heating control unit that compares the detected temperature of the first temperature detector with the control temperature to control the output of the heater are provided.

(E) Action That is, the temperature of the dry air coming out of the heater is detected by the first temperature detector, and the heating controller controls the output of the heater by comparing the temperature with the control temperature. Control the temperature.

The control temperature is determined by the control temperature determining unit based on the temperature detected by the second temperature detector, which is the temperature of the dry air cooled by the cooler.

The detected temperature detected by the second temperature detector has a substantially proportional correlation with the solvent gas concentration, and the lower the detected temperature, the higher the cooling capacity of the cooler.

Therefore, in the temperature range where the solvent gas concentration in the drying chamber does not reach the lower explosion limit concentration, if the detection temperature of the second temperature detector is low, the control temperature determination unit determines a high control temperature, and if the detection temperature is not high, The heater output is controlled by determining a low control temperature.

(F) Example Hereinafter, referring to the drawings, referring to FIG. 4, a dryer of a type for drying clothes washed with a petroleum solvent and recovering the solvent is shown in FIG. And a drying chamber 3 having a horizontal shaft type rotary drum 2 in the upper stage,
A recovery tank 4 having a U-shaped passage is formed in the lower stage.

The drying chamber 3 is provided with a clothes inlet / outlet and a door 5 on the front surface, the rotary shaft 6 of the rotary drum 2 is penetrated on the rear surface, an inlet 7 is provided at the front of the bottom portion, and an outlet 8 is provided at the rear thereof.

The recovery tank 4 is connected to the inlet 7 and the outlet 8,
A heater 9 using steam or the like is arranged near the inlet 7, and a cooler 10 using cold water or the like is arranged near the outlet 8.
A fan 11 is arranged in the middle. A first temperature detector that detects the temperature of the dry air heated by the heater 9
12 and a second temperature detector 13 for detecting the temperature of the dry air cooled by the cooler 10. This detector 12,1
3 is composed of a thermistor.

The rotary drum 2 has a large number of ventilation holes formed on the circumferential side. A seal member 14 made of felt is attached to an intermediate portion in the front-rear direction of the rotary drum 2, and the annular flange 15 of the drying chamber wall is shaped like a trumpet from the front. It is in sliding contact.

When the fan 11 is driven, the dry air heated by the heater 9 enters the drying chamber 3 through the inlet 7, flows through the drum 2, the outlet 8, the cooler 10, the fan 11, and the heater 9 in this order and circulates. Dry air presses the seal member 14 from all directions,
Improves sealing performance. Further, the dry air is cooled by the cooler 10 to condense the liquefied solvent and liquefy it, and makes it drop and flow out to the recovery site.

Then, the dry air is heated by the heater 9 and cooled by the cooler 10, and then the first and second temperature detectors 12, 1 respectively.
The temperature is detected by 3.

The temperature signals from the first and second temperature detectors 12 and 13 are input together with a start signal to a microcomputer (hereinafter, microcomputer) 16 including CPU, ROM, RAM, I / O, etc. The drive signal is output and controlled. The control block diagram is shown in FIG. 1, and the microcomputer 16 is an operation time counter for counting the dry operation time for control.
18, a control temperature setting unit 19 for setting a control temperature for heating control of the heater 9, a temperature comparison unit 20 for comparing the detected temperature of the first temperature detector 12 with the control temperature, and the temperature comparison unit 20.
A heating control unit 21 that controls the heating of the heater 9 is configured based on the comparison result.

The operation of such a configuration will be described based on the flowchart of FIG. It should be noted that the ROM has a safe lower limit concentration (0.42
%), The correlation data of the dry air temperature at the outlet of the heater 9 and the dry air temperature at the outlet of the cooler 10 are stored.

The lower safety limit concentration is a value obtained by multiplying the lower explosion limit concentration by a safety factor (for example, 0.7).

This is because the dry air is not rectified in the drying chamber 3 or the recovery tank 4, so that a partial blow-up or a portion with a high wind speed occurs. Therefore, the detection temperature of the first temperature detector 12 and the second temperature detector 13 is higher than the actual temperature at the location of the blow-in, and the control temperature is set low, so that the solvent gas concentration becomes low. Further, in a place where the wind speed is fast, the detected temperature becomes low and the control temperature is set high, so that a large amount of the solvent in the rotary drum 2 evaporates and the solvent gas concentration becomes high. It is safe for the solvent gas concentration to be low, but if the solvent gas concentration is high, it will be extremely dangerous as it approaches the explosion limit concentration. To account for such variations, by setting the control temperature at a concentration slightly lower than the lower explosive limit concentration, even if the detected temperature is lower than the actual temperature and the solvent gas concentration becomes high, the lower explosive limit concentration It is lower and can be controlled safely.

First, when the start key 17 is operated, the microcomputer 16
First, the rotary drum 2, the heater 9, the cooler 10, and the fan 11 are driven. Then, the operating time of the low temperature drying is set in the counter 18 based on the temperature initially detected by the second temperature detector 13, that is, based on the cooling capacity.

Next, the microcomputer 16 causes the control temperature setting unit 19 to compare the temperature detected by the second temperature detector 13 with the control temperature table by the time when the heating by the heater 9 rises, or when it rises to some extent. The highest temperature that safely corresponds to the detected temperature at each time is selected and set as the control temperature. For example,
If the cooler outlet temperature is 27 ° C, the control temperature can be 50 ° C.

On the other hand, the detection by the first temperature detector 12 is also started, and the microcomputer
16 is a temperature comparison unit 20, which compares the temperature after drying air heating with the control temperature, and if there is a comparison unit output above the control temperature,
The heating control unit 21 turns the heater 9 OFF or weakly to control the temperature.

In this way, the heater 9 is controlled by the heating controller 21, the maximum drying air temperature that can be taken at that time is maintained, and the low temperature drying operation is executed safely and efficiently.

When the operation time counter 18 ends, the process moves to the next process such as high temperature drying operation.

(G) Effect of the Invention According to the present invention, a safe and efficient clothes dryer can be provided because it can be dried using the highest temperature drying air in a safe concentration range that does not cause an explosion. It is possible.

[Brief description of drawings]

FIG. 1 is a control block diagram of a clothes dryer according to the present invention, FIG. 2 is a flow chart for explaining the operation, and FIG. 3 is a correlation diagram of cooler outlet temperature, drying air temperature and solvent gas concentration,
FIG. 4 is a side sectional view. 2 ... rotating drum, 3 ... drying room, 4 ... recovery tank, 7 ...
… Inlet, 8 …… outlet, 9 …… heater, 10 …… cooler,
11 ... Fan, 12 ... First temperature detector, 13 ... Second temperature detector, 16 ... Microcomputer, 19 ... Control temperature setting section, 21 ...
… Heating controller.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-59-14891 (JP, A) JP-A-58-216096 (JP, A) Actually opened 63-103890 (JP, U)

Claims (1)

[Claims] 1. A recovery chamber comprising a drying chamber for storing clothes washed with a petroleum solvent, an inlet and an outlet for dry air provided in the drying chamber, and a recovery tank for communicating the inlet and the outlet. A fan for circulating the dry air between the drying chamber and the recovery tank, a heater provided near the inlet in the recovery tank, a heater for heating the dry air, and provided near the outlet A cooler for cooling the dry air to condense the solvent; a first temperature detector provided near the inlet for detecting the temperature of the dry air heated by the heater; and a temperature of the dry air cooled by the cooler. And a second temperature detector for detecting the temperature, the temperature of the solvent in the drying chamber is set to a control temperature below the explosion lower limit concentration in accordance with the change in the temperature detected by the second temperature detector. Control temperature setting unit and the first temperature detection Clothes dryer, characterized in that a heating control section for controlling the output of the heater by comparing the detected temperature of the and the control temperature.