JPH038797B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Industrial Application Field The present invention relates to a clothes dryer for drying clothes washed with a petroleum-based flammable solvent. (b) Prior Art An example of a dry cleaner that washes and dries clothes using a petroleum-based flammable solvent is disclosed in Japanese Patent Application Laid-open No. 60-99300. Here, drying air heated by a heater is used during drying, but if the filter becomes clogged during drying operation and the concentration of solvent gas in the drying chamber increases, this concentration will be detected and the heating will be stopped. Stop operation and issue a warning. (c) Problems to be Solved by the Invention As described above, in dry cleaners that use petroleum-based solvents, the amount of air blown is increased during drying operation so that the concentration of solvent gas is below the lower explosive limit concentration. However, when the temperature of the clothes is low, the drying efficiency cannot be improved even though a large amount of high-temperature drying air is sent, and on the other hand, it was necessary to accurately detect clogged filters to prevent explosions. The present invention aims to easily prevent the risk of explosion during drying operation in a clothes dryer that uses petroleum-based solvents. (d) Means for Solving the Problems The clothes dryer of the present invention includes a drying chamber for storing clothes washed with a petroleum-based flammable solvent, and a circulation path for circulating drying air in the drying chamber. , a blowing means disposed in this circulation path, a heating means for heating the drying air, a condensing means for condensing the drying air after heat exchange with the clothes, and a temperature sensor for detecting and outputting the temperature of the drying air. a comparison means for comparing the temperature signal from the temperature sensor with a predetermined temperature lower than the flash point temperature of the flammable solvent; and control means for instructing to stop driving only the heating means when the temperature of the drying air is higher than the predetermined temperature, in response to a signal from the comparison means. (E) Effect The temperature of the drying air sent into the drying chamber is measured by a temperature sensor, and the temperature from the sensor is adjusted so that this temperature becomes a predetermined temperature lower than the flash point temperature of the flammable solvent. An operation control means controls the heater and fan based on the signal. In other words, turn on the heater so that the temperature of the drying air remains at the specified temperature.
OFF, then turn the fan ON continuously. Therefore, low-temperature drying air without the risk of explosion is fed into the drying chamber, and the drying efficiency is maintained by, for example, continuously feeding a large amount of drying air. (F) Embodiment To explain the mechanism of the dry cleaner based on FIG. 2, 1 is a drum that rotates at a low speed during washing and drying operations and at a high speed during a dehydrating operation.
It is located inside the washing/drying room 2. 3 is a pump that supplies a petroleum solvent (flash point temperature: 42° C.) from a tank 4 to the washing/drying chamber 2 during washing operation, 5 is a liquid supply valve, and 6 is a filter. Reference numeral 7 denotes a drain valve for returning the solvent in the washing/drying chamber 2 to the tank 4 at the time of liquid removal and draining. Here, the washing/drying room 2 has a circulation path 10 with an inlet 8 and an outlet 9 opened on the left and right sides of the upper part. This circulation path 10 is provided with a lint filter 11, a fan 12, a condensing device 13 consisting of a pipe for passing cold water, etc., and a heater 14 such as electric or steam heater 14 in this order from the inlet 8 to the outlet 9. 15 is a motor that drives the fan 12; 16 is a temperature sensor such as a thermistor that is located at the outlet 9 and detects the temperature of the air circulating in the washing/drying room 2; and 17 is a solvent condensed and liquefied by the condensing device 13. This is a water separator that collects water, separates it, and then returns it to tank 4. As shown in FIG. 1, a motor 18 for driving the drum 1, a pump 3, a fan motor 15,
Heater 14, liquid supply valve 5, liquid drain valve 7, and condensing device 1
The cold water valve 19 for 3 is controlled according to an operation program built into a microcomputer 20 as an operation control means, and the microcomputer 20 receives predetermined signals from an input unit 21 such as an operation switch and a temperature sensor 16. A signal is input. In particular, the output voltage from the temperature sensor 16 is constantly compared with the ladder output from the ladder circuit 22 by the comparator 23, and is read into the microcomputer 20 itself as a temperature signal. Note that the ladder circuit 22 may be omitted and the comparator 23 may be provided with a changeable reference input. The operation program stored (incorporated) in the microcomputer 20 includes liquid supply, washing,
Basically, each operation of draining, deliquid, and drying (recovery) is executed sequentially, and the time can be changed as appropriate.
It is possible to omit driving. Here, the drying (recovery) operation will be explained based on the flowchart of FIG. 3. That is, when the program shifts to a drying operation, or in an independent drying operation, the temperature of the drying air measured by the temperature sensor 16 is first compared with a predetermined temperature lower than the flash point temperature of the petroleum solvent, for example, 40°C. . The measured temperature
If it is below 40℃, heater 14, fan motor 1
5 and the drum drive motor 18, and turn on the liquid supply valve 5.
and close the drain valve 7 and open the cold water valve 19.
Further, the microcomputer 20 controls the heater 14 to be turned off if the temperature exceeds 40°C. Thus, in the drum 1, the clothes washed with the solvent and containing the solvent are dried by drying air at a low temperature below the flash point temperature, and in the condensing device 13, the solvent gas is efficiently condensed and liquefied because the temperature is low. The water is then sent to the water separator 17. Generally, it is said that drying efficiency is improved if drying operation is performed using high-temperature drying air, but such efficiency becomes an issue in low-temperature drying as in this embodiment.
However, in this embodiment, while using a heater with the same amount of heat as the conventional heater, the amount of air blown is designed to be large in advance, and the temperature of the drying air is lowered without reducing the total amount of heat given to the clothes, thereby avoiding an extension of the drying operation time. be. here,
The following Tables 1 and 2 show that using heaters with the same heat output (1224W) and at the same outside temperature (17℃), the air flow rate was 2.65.
The measurement results are shown when the drying air temperature was lowered to 39°C at m ³ /min and when the drying air temperature was raised to 83°C at air flow rate of 0.83m ³ /min. In addition, Tables 3 and 4 show that using heaters with the same calorific value (1224 W) and at approximately the same outside temperature (15°C to 17°C), the amount of air blown was 2.53 m ³ /
The measurement results are shown when the drying air temperature was lowered to 40°C per minute and when the drying air temperature was raised to 83°C with an air flow rate of 0.88m ³ /min.

【table】

【table】

【table】

【table】

[Table] In other words, although Tables 1 and 3 show low-temperature drying operation, there is no significant difference in the time required for the drying operation compared to the high-temperature drying operation in Tables 2 and 4, and the specified drying efficiency cannot be maintained. ing. The drying operation time can be set slightly longer in advance in the case of low temperature drying operation. The heater 14 is divided into two, one is operated continuously and the other is operated intermittently by the temperature sensor 16,
A predetermined temperature may be maintained by turning the divided heater 14 ON and OFF. Alternatively, the heating amount may be kept constant and the speed of the fan motor 15 may be controlled to increase or decrease the amount of air blown to maintain a predetermined temperature. In this embodiment, the solvent is recovered, but the condensing device 13 is omitted, and the outside air is sucked into the drying chamber 2 via the heater 14 by the fan 12, and then released to the outside after drying. Also good. Furthermore, in this embodiment, low-temperature drying is performed for the entire operating time by turning the heater 14 on and off and increasing the air flow rate of the fan 12 in advance. If the first 12 minutes are a low-temperature drying operation, heat exchange is effectively performed with the clothing, which is initially at a low temperature, during this operation. Even if high-temperature dry air is supplied from the beginning, it often passes through without heat exchange, resulting in waste. After this low-temperature drying, the temperature of the clothes has already risen, so if you perform high-temperature drying from this point on, the overall drying efficiency will increase. Incidentally, compared to the case where high temperature drying was performed from the beginning under almost the same conditions, the time could be reduced by about 3 minutes. Table 5 shows the case where high temperature drying was continued, and Table 6 shows the case where high temperature drying was performed following low temperature drying. This embodiment can be easily applied to a dryer for clothes washed with normal city water.

【table】

[Table] (G) Effects of the Invention According to the present invention, an extremely safe clothes dryer is provided with a simple configuration, which can carry out drying operation without the risk of explosion and at an efficiency close to normal efficiency. It is possible.

[Brief explanation of the drawing]

Fig. 1 is a control circuit diagram of a dry cleaner incorporating a drying function according to the present invention, Fig. 2 is an overall mechanical diagram,
FIG. 3 is a flowchart for explaining the operation. 2...Washing and drying room, 11...Lint filter,
12... Fan, 13... Condensing device, 14... Heater,
15...Fan motor, 16...Temperature sensor, 20
...Microcomputer, 23...Comparator.

Claims (1)

[Claims] 1. A drying room for storing clothes washed with a petroleum-based flammable solvent, a circulation path for circulating drying air generated by a fan in this drying room, and a drying chamber installed within this circulation path. A heater for heating the air, a condensing device for condensing the drying air after heat exchange with clothing, a temperature sensor for detecting and outputting the temperature of the drying air, and a temperature signal from the temperature sensor and the temperature of the flammable solvent. It comprises a comparator that compares the temperature with a predetermined temperature lower than the flash point temperature, and a control means that controls the operation of the fan, heater, and condensing device, and the control means drives the fan, heater, and condensing device during drying. A clothes dryer, characterized in that the clothes dryer operates to stop driving only the heater when the temperature of the drying air is higher than the predetermined temperature based on a signal from a comparator.