JPH0775640B2 - 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 petroleum solvent.

[0002]

2. Description of the Related Art When a laundry washed with a petroleum solvent is dried, there is a risk of catching fire if the drying operation is performed at a high temperature.
Therefore, a gas sensor is provided on the exhaust port side of the drying chamber outlet,
A gas sensor for detecting a solvent gas is disclosed in Japanese Patent Laid-Open No. 60-2294 (D06F58 / 28). As this gas sensor, a semiconductor type or a catalytic combustion type is used.

[0003]

In the conventional example, the solvent gas may be an ignition source because the detection part of any gas sensor is heated to 200 to 500 ° C. for detection. . Therefore, the gas sensor-accommodating chamber must be provided with an ignition preventing means having an explosion-proof structure, which makes the structure complicated and expensive. Further, since the gas sensor is exposed to the solvent gas for a long time, there are problems that the durability is poor due to corrosion and the reliability of the detection is deteriorated due to deterioration of detection accuracy.

The present invention solves the above problems.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to a drying chamber for containing an object to be dried that has been washed with a solvent, an outer tank for rotatably accommodating the drying chamber, and a supply port and a drain provided in the outer tank. It was composed of a circulation air passage connecting the air vents, and an air blower, a condenser, and a heater that were sequentially installed in the circulation air passage from the exhaust port side .
In the dryer, the circulation air passage on the discharge side of the blower is connected to the circulation air passage on the suction side of the blower, and a part of the dry air discharged from the blower is circulated on the suction side of the blower. a bypass passage for returning to, Rutotomoni provided in the bypass passage
It is maintained at a predetermined temperature, drying air in flowing into the bypass passage
Solvent gas concentration exceeds the saturation concentration at the specified temperature
A condensing unit to condense the solvent when that a reservoir to accumulate the solvent condensed by said condensing portion, and a heating section for heating the solvent, which is accumulated within the reservoir, provided in the reservoir, the reservoir
When the solvent is not stored, it is stored through the condenser section.
The temperature of the dry air flowing into the reservoir is detected, and the solvent is stored in the reservoir.
A temperature sensor for detecting the temperature of the solvent when the solvent is stored, and a control circuit for controlling the drying operation by judging the solvent gas concentration based on the detection output from the temperature sensor are provided.

When the dry air circulates in the circulation air passage, the air is blown into the bypass passage from the discharge side of the air blower by the blowing pressure of the air blower .
Part of the drying air to have you influx. The concentration of solvent gas in the dry air is
If it is lower than the saturation concentration at the specified temperature,
No condensation occurs and the solvent does not accumulate in the reservoir. This and
The temperature sensor should detect the temperature of the dry air.
It On the other hand, the solvent gas concentration in the dry air is
If the saturation concentration is exceeded, the condensation of the solvent will occur in the condensation section,
The condensed solvent accumulates in the reservoir. And inside the reservoir
The solvent is heated by the heating unit. At this time, the temperature sensor
The sir will sense the temperature of the heated solvent.
In this way, the temperature of the dry air or the temperature of the solvent is detected.
As a result, the detection output of the temperature sensor differs. Control
The control circuit has a high solvent gas concentration due to this difference in detection output.
Determine low to control drying operation.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 is an outer tank having a closed structure provided in a frame (not shown) of a solvent recovery type dryer, and 2 is a drum serving as a drying chamber rotatably arranged in the outer tank 1. Therefore, it has a large number of through holes 3 around it. Reference numeral 4 is a drive motor for rotating the drum 2, and 5 is a circulation air passage connecting a hot air supply port 6 provided in the upper part of the outer tub 1 and an exhaust port 7 provided in the lower part thereof. A lint filter-8, a blower 9, a condenser 10, and a heater 11 are arranged in the order 5 from the exhaust port 7 side. The heater 11 generates heat by the steam sent from the outside air, and heats the dry air in the circulation air passage 5. Then, the heater 11 is controlled so that the temperature of the portion of the supply port 6 becomes about 60 ° C. That is, the temperature sensor 12 attached to the supply port 6 constantly detects the temperature of the supply port 6.

Reference numeral 13 is an outside air intake port provided in the dry air passage 5 on the windward side of the heater 11, and 14 is an intake valve for opening and closing the intake port 13. Reference numeral 15 is a blower device 9 in the circulation air passage 5.
A partition wall for partitioning between the condenser 10, 16 will open and close the partition wall 15, an intermediate valve for switching the drying air circulating, 17
Exhaust valve exhaust port formed in a circulation air passage 5 between the blower 9 and the partition walls 15, 18 for opening and closing the discharge port 17,
Reference numeral 19 is a solvent recovery port for taking out the solvent condensed in the condenser 10.

Reference numeral 20 denotes a bypass passage communicating between the discharge-side circulation air passage 5 of the blower 9 attached to the circulation air passage 5 and the suction-side circulation air passage 5 of the blower 9. A part of the discharged dry air is returned to the suction side circulation air passage 5, which will be described in detail below with reference to FIG.

The bypass passage 20 is branched from the circulation air passage 5 on the suction side of the blower 9 and a metal pipe 21 such as copper or brass having good thermal conductivity and branched from the circulation air passage 5 on the discharge side of the blower 9. Equivalent metal pipe 22 and this metal pipe 2
The thermal insulation pipe 23 is made of Teflon, glass, or the like, which is connected between 1.22.

Reference numeral 24 denotes a condenser provided on the metal pipe 22. The condenser 24 is composed of a heater 25 wound around the metal pipe 22 and a cooling cylinder 26 for cooling air by blowing air around the heater 25. The metal pipe 22 is constantly controlled so as to have a predetermined temperature of about 38 ° C. 27 is a heating unit provided on the metal pipe 21. The heating unit 27 is a heater 2
No. 8 is attached and the metal pipe 21 is controlled to be constantly at about 60 ° C. Reference numeral 29 denotes a storage portion provided in the heat insulating pipe 23 so that the solvent condensed in the condenser portion 24 can be stored therein. Reference numeral 30 is a temperature sensor composed of a negative characteristic thermistor for detecting the temperature of the condensed solvent in the reservoir 29.

Here, the part of the dryer showing the maximum solvent gas concentration during the drying operation is the exhaust port 7 provided below the outer tank 1.
Therefore, the temperature around this point is below the flash point temperature of petroleum solvent .
Controlling the drying temperature so as to maintain the temperature is safe. However, it is safe if the flash point temperature is exceeded.
To achieve this, the solvent gas concentration must be lower than the explosion lower limit concentration.
is necessary. When the metal pipe 22 has a predetermined temperature of 38 ° C.
The saturation concentration in the column corresponds to the lower explosion limit concentration. The exhaust
The concentration of solvent gas in the dry air at the mouth of 7 is lower than the explosion limit.
If the concentration is lower than the concentration, it will flow into the bypass 20.
The solvent in the dry air that has been received is not condensed in the condenser 24.
Therefore, the solvent does not accumulate in the reservoir 29, and the temperature sensor
Sir 30 is the temperature of the dry air flowing in from the metal pipe 22.
Will be detected. On the other hand, drying at the exhaust port 7 parts
When the concentration of solvent gas in the wind exceeds the lower limit concentration of explosion mentioned above
In the case of dry air flowing into the bypass passage 20,
The solvent is condensed in the condenser section 24 and stored in the storage section 29.
Be done. Then, the solvent in the reservoir 29 is heated by the heating unit 27.
When heated, the temperature sensor 30 detects the temperature of the solvent.
It will be.

Reference numeral 31 is a micro computer serving as control means.
A computer (hereinafter referred to as a microcomputer) will be described below with reference to a block diagram of the control mechanism shown in FIG. That is, based on the input information from the input key circuit 32 composed of various operation key groups, the temperature setting device 33, etc., the various on-off valves, the drive motor 4, the blower 9, the condenser 10, etc. It controls the operations of the load 34, the display device 35, the buzzer circuit 36, and the like. The temperature setting device 33 is for presetting the temperature of the hot air supply port 6 during the drying process, and is operated by the ten keys of 0-9.

In the above-mentioned structure, the dryer of this embodiment successively performs the drying under the control of the microcomputer 31, and the control will be described with reference to the flowchart of FIG.

When the drying is started, the driving motor 4, the air blower 9, the condenser 10 and the heater 11 are turned on (S-1), and the air blower 9 sucks the air from the exhaust port 7 of the outer tank 1. The dry air is circulated through the circulation air passage 5 in the direction of the arrow. Since the temperature setting device 33 sets the temperature of the dry air at the portion of the supply port 6 to about 60 ° C., the heater 11 is controlled by the detection of the temperature sensor-12 (S-2). During that time, the solvent gas contained in the dry air is condensed in the condenser 10, and the condensed solvent is recovered from the solvent recovery port 19 into a container (not shown) until a preset time has elapsed.

On the other hand, part of the dry air is introduced into the bypass 20. Condensing part 2 of metal pipe 22 of bypass 20
No. 4 is introduced because the cool air is blown into the heater 25 and the cooling cylinder 26 to control the temperature to a predetermined temperature (about 38 ° C.).
The solvent gas concentration in the dry air is
Above the saturation concentration, to condense Solvent from the drying air in. The condensed solvent travels along the inner peripheral wall of the metal pipe 22 and accumulates in the reservoir 29. The temperature sensor 30 flows into the bypass passage 20 until the condensed solvent is accumulated ,
Suruga detects the temperature of the drying air through the output, to start detection of the solvent temperature the solvent comes collected in reservoir 29. The solvent accumulated in the storage section 29 is heated by heat conduction from the metal pipe 21 heated to about 60 ° C. by the heating section 27, and the solvent temperature is increased.
Every time rises to the immediate time of change. Thus the temperature of the dry air,
Alternatively, the detection output of the temperature sensor 30, which is the temperature of the solvent
Is converted to a temperature and compared with the determination temperature (about 50 ° C.) (S-3). And the concentration of solvent gas in the dry air is low.
Therefore, when the detection output of the temperature sensor 30 is lower than the determination temperature because the solvent does not condense, the circulation returning to the outer tank 1 is repeated until the set time has elapsed (S-4). On the other hand, since the solvent gas concentration in the dry air is high
When the detection output is higher than the determination temperature due to the condensation of the solvent on the high temperature, the high temperature is maintained for a predetermined time (for example, 1 to 2).
(S-5), and if it is less than the predetermined time, the circulation returning to the outer tank 1 is repeated until the set time elapses (S-4). If more than the specified time, dry
The concentration of solvent gas in the wind reached the lower limit of explosion, leading to ignition.
If there is a possibility that there is a possibility that the driving motor 4, the blower 9, the condenser 10 and the heater 11 are stopped (S-6) , an abnormality is notified and the drying process is stopped.

When the solvent accumulates in the reservoir 29 and the solvent overflows from the reservoir 29 before the elapse of the set time, the negative pressure on the suction side of the blower 9 causes the metal pipe communicating with the circulation air passage 5 on the exhaust port 7 side. It is dripped into the circulation air passage 5 via 21.

Before the drying is completed, the intake valve 14 provided in the circulation air passage 5 is opened to suck the outside air, and the partition wall 15 is provided.
Is closed by the intermediate valve 16. Then, the exhaust valve 18 is opened to discharge the dry air to the outside of the machine to lower the temperature of the dried product, thereby lowering the temperature of the dried product after completion of the drying and making it easier to take out, cooldown, and solvent odor from the dried product. A deodorizing step for removing the impurities is performed for a predetermined time, and the drying is completed.

[0020]

According to the present invention, the concentration of the solvent gas can be detected by the temperature sensor, and the structure is simple and the cost is low. Moreover, the temperature sensor does not impair the detection accuracy due to the solvent gas.

[Brief description of drawings]

FIG. 1 is a dryer for detecting a solvent temperature according to the present invention to determine a solvent gas concentration.

FIG. 2 is a detailed view of a solvent temperature detection unit also attached to the bypass passage.

FIG. 3 is a block diagram of a control mechanism.

FIG. 4 is a flowchart showing a drying process adopting the present invention.
To.

[Explanation of symbols]

 1 Outer Tank 2 Drum (Drying Room) 5 Circulating Air Path 6 Supply Port 7 Exhaust Port 9 Blower 10 Condenser 11 Heater 20 Bypass Path 30 Temperature Sensor-

Claims (1)

[Claims] 1. A drying chamber for accommodating an object to be dried that has been washed with a solvent, an outer tank rotatably accommodating the drying chamber, and an outer chamber.
And air circulation duct that connects the supply port and exhaust port formed in a bath, air blower mounted in order from the exhaust port side in the air circulation path, the configuration and dryer and a condenser and heater, wherein Circulation air passage on the discharge side of the air blower and circulation air passage on the suction side of the air blower
Communicating the door, the blower and the bypass passage a part of the drying air discharged back into the suction side air circulation duct of the blower from being maintained in Rutotomoni predetermined temperature provided in the bypass passage, the bypass passage The concentration of solvent gas in the dry air flowing into the
A condensing unit to condense the solvent exceeds the saturation concentration at the temperature, a heating unit for heating the reservoir to accumulate the solvent condensed by said condensing portion, a solvent which is accumulated in the <br/> reservoir, the savings
It is provided inside the reservoir and the solvent is not stored in the reservoir.
The dry air that has flowed into the reservoir through the condenser.
When the temperature is detected and the solvent is stored in the reservoir, the solvent
And a control circuit for controlling the drying operation by determining the solvent gas concentration based on the detection output from the temperature sensor.