JPH07689A - Dryer - Google Patents

Abstract

PURPOSE:To prevent the abnormal generation of a solvent gas by preliminarily driving a cooler in the stopped state of a heating machine, when the temperature in a drying chamber is high by the preheat of the previous drying at drying clothes cleaned with a solvent, and circulating a cooling air in a drying chamber to cool the drying chamber. CONSTITUTION:When clothes cleaned with a petroleum solvent are dried, the clothes are inputted into a rotating drum 3, and a start key is ON. At this time, in a control device, a drying chamber internal temperature by a drying chamber temperature sensor 22 is compared with a prescribed temperature (the lower flash point temperature of the solvent: about 40 deg.C). When the temperature in the drying chamber 2 is rather high by the effect of the preheat in the previous drying, and exceeds the lower flash point temperature, a cooling air circulating means is operated prior to drying operation. Namely, a blower 12 is driven in the state where steam valves 7, 8 are closed to stop a heater 6, a cooling valve 17 is opened to drive a cooler 16, and a cooling air is circulated in the drying chamber 2 to cool the drying chamber 2.

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 Examined Patent Publication No. 3-8797, when a laundry washed with a petroleum solvent is dried, air is circulated in a heater, a drying chamber and a cooler in this order. . Under this circulation, hot air is generated in the heater, the solvent is evaporated from the laundry by the hot air, and then the hot air is cooled in the cooler to recover the evaporated solvent from the laundry.

At the start of such a drying operation, if the temperature in the drying chamber is considerably high due to the residual heat of the previous drying, etc., the laundry gas contains a large amount of solvent after washing, and the solvent gas is abnormal. Occurs and is dangerous.

Further, when the laundry is added to the drying chamber by suspending the drying operation and the drying operation is restarted, the laundry containing a large amount of solvent is already added while the temperature in the drying chamber is already high. Similarly, the solvent gas is generated abnormally, which is dangerous.

On the other hand, if the temperature in the drying chamber at the start of the drying operation is low, the heater is driven when the drying operation is performed.
Since the temperature is controlled to stop, the temperature inside the drying chamber does not rise easily,
It takes a long time to dry and the drying efficiency is poor.

[0006]

SUMMARY OF THE INVENTION According to the present invention, control is performed in accordance with the temperature in a drying chamber to avoid the danger of abnormal occurrence of a solvent gas and prevent the reduction of drying efficiency. It is intended to provide a dryer.

[0007]

According to a first aspect of the present invention, there are provided a drying chamber for storing solvent-washed laundry, a heater, a cooler, and the heater, the drying chamber and the cooler. An air blower that circulates the air in order is provided, and under this circulation, hot air is generated by the heater, the solvent is evaporated from the laundry by this hot air, and then the hot air is cooled by the cooler and evaporated from the laundry. In a basic dryer for performing the drying operation, the solvent is collected, and a drying chamber temperature sensor for detecting the temperature in the drying chamber, and a temperature detected by the drying chamber temperature sensor before the drying operation is set to a predetermined temperature. When the comparison result of the comparison means and the comparison result that the detected temperature is higher than the predetermined temperature is obtained by this comparison means, the cooler and the blower are driven in the stopped state of the heater before the start of the drying operation. Circulates cooling air And a that cooling air circulating means.

Further, as the structure of claim 2, in the basic dryer, an interrupting means for interrupting the drying operation by opening the door of the drying chamber and the like, and the heating operation before restarting the drying operation after the interruption. The cooling air circulation means for driving the cooling device and the blower to circulate the cooling air when the air conditioner is stopped is provided.

Further, according to a third aspect of the present invention, in the basic dryer, a drying chamber temperature sensor for detecting a temperature in the drying chamber and a temperature detected by the drying chamber temperature sensor before starting the drying operation are set to predetermined temperatures. When the comparison result obtained by the comparison means and the comparison result that the detected temperature is lower than the predetermined temperature is obtained by the comparison means, the heater is driven to bring the detected temperature up to a predetermined temperature before the drying operation is started. And a heater control means for making it reach.

[0010]

In the structure of claim 1, when starting the drying operation, if the temperature inside the drying chamber is considerably high due to the residual heat of the previous drying, the detection result of the drying chamber temperature sensor is higher than the predetermined temperature. Is obtained. Then, prior to the start of the drying operation, the cooler and the blower are driven with the heater stopped, and the cooling air circulates in the drying chamber. By this circulation, the drying chamber is cooled. After that, the drying operation is started, but the state where the temperature inside the drying chamber is high is no longer present, and the solvent gas is not abnormally generated.

According to the second aspect of the present invention, after the drying operation is interrupted and before the drying operation is restarted, the cooler and the blower are driven with the heater stopped, and the cooling air circulates in the drying chamber to dry. The room is cooled. When the drying operation is interrupted, the door is opened and laundry is added. If the drying operation is restarted immediately after that, solvent gas is abnormally generated because the temperature inside the drying chamber is high. However, by cooling the drying chamber before restarting the drying operation as described above,
Solvent gas does not occur abnormally.

According to the third aspect of the present invention, at the time of starting the drying operation, when the comparison result that the temperature in the drying chamber is lower than the predetermined temperature is obtained, the heater is driven prior to the start of the drying operation and the drying chamber is started. The temperature is raised to near the predetermined temperature. As a result, the drying operation is started when the temperature of the drying chamber is at an appropriate height, and the drying time is shortened.

[0013]

1 and 2 show the structure 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 inside is a rotating drum rotatably arranged in the drying chamber 2, into which laundry washed with a petroleum solvent is put in with the door 3a open. To be done. The rotary drum 3 has a cylindrical shape and has a large number of ventilation holes on the peripheral wall. A drum motor 4 drives the rotary drum 3.

Reference numeral 5 is an intake port provided in the upper part of the dryer main body 1, and 6 is a heater connected to the 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). Reference numeral 10 is an introduction path connecting the heater 6 and the drying chamber 2;
Is a discharge passage connected to the lower part of the drying chamber 2, 12 is a blower connected to the discharge passage 11, and 13 is a blower 12
A connecting path connected to the rear side of the dryer main body 1
Reference numeral 14 is an exhaust port provided at the upper end of the dryer main body 1 at the end of the communication path 13.

Reference numeral 15 is a circulation passage provided in the upper part of the dryer main body 1 so as to connect the heater 6 and the vicinity of the upper portion of the communication passage 13, and 16 is a cooler arranged in the circulation passage 15. . This cooler 16 has a cooling valve 17 and a refrigerator 1
The cooling pipes 19 are connected to each other. Reference numeral 20 is a switching means, that is, a switching valve, which selectively moves to the solid line position for closing the intake port 5 or the dashed line position for opening.

When the switching valve 20 moves to the position indicated by the solid line, a circulation drying path is formed. 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 heater 6 is hit by the wind from the circulation path 15 side 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 rotary drum 3. This drying evaporates the solvent from the laundry and the hot air contains the solvent gas. On the other hand, hot air is deprived of heat. After that, this hot air is discharged from the discharge path 1
1, passing through the blower 12 and the connecting path 13 to reach the vicinity above the connecting path 13. At this point, the hot air is influenced by the flow of air from the circulation path 15 to the heater 6 and is drawn into the circulation path 15. Then, the hot air is positively cooled by the cooler 16, the solvent gas is condensed, and the solvent is recovered. Then, the heater 6, the drying chamber 2, and the cooler 16 are provided.
The solvent is recovered and dried while hot air is circulated in this order. In the figure, solid arrows indicate the flow of hot air at this time.

On the other hand, when the switching valve 20 moves to the alternate long and short dash line position, an exhaust drying path is formed. That is, in the state where the heater 6 operates similarly, the blower 1
When 2 is driven, 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. This hot air similarly enters the drying chamber 2 to dry the laundry and contains solvent gas. On the other hand, hot air is deprived of heat.
Then, the hot air passes through the discharge passage 11, the blower 12, and the communication passage 13 to reach the vicinity of the upper portion of the communication passage 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 from the exhaust port 14 to the outside. In the figure, the broken line arrow indicates the flow of hot air at this time.

Reference numeral 21 is a hot air temperature sensor which is arranged on the downstream side of the heater 6 in the introduction passage 10 and detects the temperature of the hot air introduced into the drying chamber 2. Reference numeral 22 denotes a drying chamber temperature sensor which is disposed in the discharge passage 11 and detects the temperature of the hot air deprived of heat by drying, that is, the temperature in the drying chamber. Reference numeral 23 denotes a cooling temperature sensor which is disposed in the circulation path 15 on the downstream side of the cooler 16 and detects the temperature of the hot air after cooling. Each of these sensors 21, 22, 23
Each consists of a thermistor.

FIG. 3 shows a block circuit of the dryer.
25 is a microcomputer for controlling the dryer, 26
Is a key operation unit for setting driving information, and 27 is the door 3
It is a door switch that is turned on and off according to opening and closing of a.
The key operation unit 26 and the door switch 27, together with the steam valves 7 and 8, the cooling valve 17, the blower 12, the drum motor 4, the switching valve 20, the hot air temperature sensor 21, the drying chamber temperature sensor 22, and the cooling temperature sensor 23, It is located around the microcomputer 25.

Next, the operation of the dryer will be described according to the flow of the program incorporated in the microcomputer 25 of FIG. When performing a drying operation, the door 3a is opened, the laundry washed with the petroleum solvent is put into the rotary drum 3, then the door 3a is closed, and the operation information is set by the key operation unit 26 to start. Operate the key. Based on the operation of the start key, the microcomputer 25 first determines the operation of the start key (step S1) and compares the temperatures before the start of the drying operation. That is, the temperature in the drying chamber detected by the drying chamber temperature sensor 22 is compared with the lower flash point temperature of the solvent which is a predetermined temperature of 40 ° C. (S2 step: corresponding to the comparing means of the present invention).

Now, when a comparative result is obtained that the time has not passed much since the previous drying and the temperature in the drying chamber is considerably high and exceeds the lower flash point temperature due to the influence of the residual heat of the previous drying, Prior to the start of the drying operation, the microcomputer 25 executes step S3, which is the cooling air circulation means of the present invention. In the same step, with the steam valves 7 and 8 closed and the heater 6 stopped, the drum motor 4 is reversely driven to reverse the rotary drum 3, the blower 12 is driven, and the cooling valve 17 is turned on. The switch 16 is opened to drive the cooler 16, and the switching valve 20 is switched to the solid line position. As a result, the cooling air cooled by the cooler 16 circulates in the drying chamber 2 to rapidly cool the drying chamber,
The drying chamber temperature detected by the drying chamber temperature sensor 22 drops as shown in FIG.

When cooling progresses and the temperature inside the drying chamber detected by the drying chamber temperature sensor 22 falls below 41 ° C. near the lower flash point temperature (S4 step), the microcomputer 2
In step 5, the steam valve 7 is opened (S5 step). The remaining steam valve 8 is opened / closed depending on whether the temperature difference obtained by subtracting the drying chamber temperature detected by the drying chamber temperature sensor 22 from the hot air temperature detected by the hot air temperature sensor 21 exceeds 8 ° C. The drying operation of controlling is executed (S
6 to S8 step). As a result, the temperature difference is about 8
It is maintained at ℃, which means that the amount of heat taken by the laundry is small and the amount of solvent evaporated from the laundry per unit time is relatively small, and the solvent gas concentration in the drying chamber is 0.6% of the lower explosion limit concentration. Maintained below. Therefore, there is no danger of explosion.

Even if the temperature in the drying chamber exceeds the lower flash point temperature, if the drying operation is immediately performed without cooling the drying chamber as described above, the temperature difference of 8 ° C. can be maintained. However, since the laundry containing a large amount of solvent suddenly continues to be exposed to high temperatures after cleaning, the amount of solvent gas generated increases abnormally, and the concentration of solvent gas in the drying chamber exceeds the above explosion lower limit concentration. . That is, the temperature of the drying chamber exceeds the lower flash point temperature and the concentration of the solvent gas exceeds the lower explosion limit concentration, which causes a danger of explosion.

While the temperature difference of 8 ° C. is maintained as described above, the temperature inside the drying chamber gradually rises as shown in FIG. Eventually, the temperature in the drying chamber detected by the drying chamber temperature sensor 22 becomes 5
When the temperature exceeds 5 ° C. (step S9), the microcomputer 25 stops the drum motor 4 to stop the rotary drum 3, stops the blower 12, closes the steam valves 7 and 8 to stop the heater 6, The cooling valve 17 is closed to stop the cooler 16 (step S10). This completes the drying operation.

By the way, during the drying operation, whether the stop key operation on the key operation unit 26 is judged or not, the door switch 2 is operated.
When it is determined that the door 3a is opened when 7 is turned off (S11, S
12 step), the microcomputer 25 executes the same step S13 or S14 as step S10 to interrupt the drying operation (steps S13 and S14 correspond to the interrupting means of the present invention). In the case of interruption by the stop key, wait until the door 3a is opened for a while thereafter (S15).
Step). Then, based on the determination of opening the door, the microcomputer 25 sets the door open flag in itself to 1 (step S16), and waits for the closing of the door 3a.

The opening of the door is usually performed to add laundry. Then, when laundry is added, the door is closed, and the start key is operated again, the microcomputer 25 judges that the door is closed by turning on the door switch 27 (step S17), and operates the start key. Is determined (S18 step), the door open flag is further determined to be 1 (S19 step), and this flag is set to 0 (S20 step).

Then, the microcomputer 25 uses S2
Return to step. At this time, the temperature in the drying chamber does not easily drop even if the drying is interrupted, and it is determined that the temperature has exceeded the lower flash point temperature, and step S3 is executed again before restarting the drying operation. As a result, the inside of the drying chamber is cooled, and the temperature inside the drying chamber detected by the drying chamber temperature sensor 22 rapidly drops after the restart key is operated as shown in FIG. When the temperature inside the drying chamber drops to around the lower flash point temperature, the microcomputer 25 executes steps S6 to S8 after step S5 to restart the drying operation.

By restarting the drying operation after cooling in this manner, the drying chamber is not suddenly maintained at a high temperature in the presence of a large amount of solvent due to the addition of laundry, and abnormal solvent gas is also generated. Is suppressed and the danger of explosion is avoided.

In the temperature comparison in step S2 before the start of the drying operation, there is no influence of residual heat from the previous drying and the temperature inside the drying chamber detected by the drying chamber temperature sensor 22 is a predetermined temperature. When the comparison result that the temperature is lower than C is obtained, the microcomputer 25 executes the step S21 which is the heater control means of the present invention, before the start of the drying operation. In the same step, the drum motor 4 is reversely driven to reverse the rotary drum 3, the blower 12 is driven, the cooling valve 17 is opened to drive the cooler 16, and the switching valve 20 is switched to the solid line position. Further, the hot air temperature detected by the hot air temperature sensor 21 is shown in FIG.
Steam valve 7, 8 so that the temperature becomes almost 50 ° C as shown in
Control the opening and closing.

As a result, the temperature inside the drying chamber detected by the drying chamber temperature sensor 22 rapidly rises. Due to this rise,
When the temperature inside the drying chamber reaches the above predetermined temperature, that is, near the lower flash point temperature and exceeds 39 ° C., the microcomputer 2
5 executes the steps S6 to S8 through the step S5 as described above, and executes the drying operation.

When the temperature inside the drying chamber is low as described above, the temperature inside the drying chamber is rapidly raised before the start of the drying operation, and then the drying operation is executed, so that the drying time can be shortened and the drying efficiency can be improved.

[0032]

According to the dryer of claim 1 of the present invention, when the temperature in the drying chamber is considerably high due to the influence of residual heat of the previous drying, the heater is stopped before starting the drying operation. Since the cooling air is circulated in the drying chamber by driving the cooler and the air blower to cool the drying chamber, it is possible to prevent the drying operation from being started when the temperature in the drying chamber is high,
Therefore, it is possible to eliminate the danger that the solvent gas is abnormally generated and explodes.

Further, according to the dryer of claim 2, before the drying operation is restarted after the drying operation is interrupted, the cooling air is blown into the drying chamber by driving the cooling device and the blower while the heating device is stopped. Since it is circulated and the inside of the drying chamber is cooled, it is possible to prevent the laundry from being added at the time of interruption and restarting the drying operation when the temperature inside the drying chamber is high, and also the solvent gas is abnormally generated and explodes. The danger can be eliminated.

Further, according to the dryer of the third aspect, when the temperature in the drying chamber is low, the heater is driven to rapidly raise the temperature in the drying chamber before starting the drying operation. The drying operation can be started when the room temperature is at an appropriate height, and the drying time can be shortened and the drying efficiency can be improved.

[Brief description of drawings]

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

FIG. 2 is a side view of the dryer.

FIG. 3 is a block circuit diagram of the dryer.

FIG. 4 is a flowchart of an operation program of the dryer.

FIG. 5 is a diagram showing changes over time in temperature and gas concentration in the dryer.

FIG. 6 is another diagram showing temporal changes in temperature and gas concentration in the dryer.

FIG. 7 is still another diagram showing changes over time in temperature and gas concentration in the same dryer.

[Explanation of symbols]

 1 Dryer Main Body 2 Drying Room 3 Rotating Drum 6 Heater 12 Blower 16 Cooler 20 Switching Valve 21 Hot Air Temperature Sensor 22 Drying Room Temperature Sensor 23 Cooling Temperature Sensor 25 Microcomputer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshiaki Miyaji 2-18 Keihan Hondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Masahiko Tsunoda 2-18 Keihan Hondori, Moriguchi-shi, Osaka Sanyo Denki Within the corporation

Claims (3)

[Claims] 1. A drying chamber for storing laundry washed with a solvent, a heater, a cooler, and a blower for circulating air in the order of the heater, the drying chamber, and the cooler. On the other hand, hot air is generated in the heater, the solvent is evaporated from the laundry by the hot air, and then the hot air is cooled by the cooler to recover the evaporated solvent from the laundry, in a dryer that executes a drying operation. , A drying chamber temperature sensor for detecting the temperature in the drying chamber, a comparison unit for comparing the detection temperature of the drying chamber temperature sensor with a predetermined temperature before the start of the drying operation, and the detection temperature by the comparison unit is higher than the predetermined temperature. When a result of comparison with the above is obtained, it is provided with a cooling air circulating means for circulating the cooling air by driving the cooler and the blower in a stopped state of the heater before starting the drying operation. And dryer. 2. A drying chamber for accommodating the laundry washed with the solvent, a heater, a cooler, and a blower for circulating the air in the order of the heater, the drying chamber and the cooler, and under the circulation. On the other hand, hot air is generated in the heater, the solvent is evaporated from the laundry by the hot air, and then the hot air is cooled by the cooler to recover the evaporated solvent from the laundry, in a dryer that executes a drying operation. , Interrupting means for interrupting the drying operation by opening the door of the drying chamber, etc., and before restarting the drying operation after this interruption, drive the cooling device and the blower in the stopped state of the heating device to generate cooling air. A drier, comprising: a cooling air circulation means for circulation. 3. A drying chamber for storing the solvent-washed laundry, a heater, a cooler, and a blower for circulating air in the order of the heater, the drying chamber, and the cooler, and under the circulation. On the other hand, hot air is generated in the heater, the solvent is evaporated from the laundry by the hot air, and then the hot air is cooled by the cooler to recover the evaporated solvent from the laundry, in a dryer that executes a drying operation. A drying chamber temperature sensor for detecting the temperature in the drying chamber, a comparison unit for comparing the detection temperature of the drying chamber temperature sensor with a predetermined temperature before the start of the drying operation, and a detection temperature lower than the predetermined temperature by the comparison unit. And a heater control means for driving the heater to bring the detected temperature to near a predetermined temperature before the start of the drying operation.