JPH05293295A - Solvent recovery type dryer - Google Patents

Abstract

PURPOSE:To diagnose quickly the trouble accompanied with abnormal temperature in operation. CONSTITUTION:The detection results of the temperatures arranged in each part inside a circulation air duct such as a thermometer 11 on the entry side of a drum, a thermometer 12 on the exit side of a drum, a thermometer 13 on exit side of a condenser, etc., are given to a controller 10. The controller 10 drives a drum driving motor la and a fan driving motor 3a, and changes over the operation state by opening and closing an intake valve 8 and an exhaust valve 9 arranged in the middle of a circulating air duct, and controls the heating temperature by a heater by opening and closing a steam inlet valve 4a and a steam outlet valve 4b for passing or breaking the steam supplied to the heater, based on the temperatures detected by each thermometer 11, 12, and 13. Furthermore, the controller 10 stores the change patterns on standing of the temperatures detected by each thermometer 11, 12, and 13 into a pattern storage part 10a, and compares it with standard change pattern being stored in a reference pattern storage part 10b so as to diagnose the trouble of each thermometer 11, 12, and 13, and informs a worker of this result by the sounding of a buzzer 15 and the indication in the display on the operation panel 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solvent recovery type drier capable of performing a recovery / drying operation for recovering a solvent remaining in an object to be dried after washing and draining.

[0002]

2. Description of the Related Art A dryer for drying an object to be dried such as clothes washed with a petroleum solvent is disclosed in, for example, Japanese Patent Laid-Open No. 3-97.
As disclosed in Japanese Patent Publication No. 98, the inside of a circulation air duct that contains a cylindrical storage tank (rotating drum) that stores a material to be dried that has been drained after cleaning and rotates around a horizontal axis in the middle thereof. In addition, a condenser, a blower fan and a heater are arranged in this order from the outlet side to the inlet side of the rotary drum, and further, an intake valve and an exhaust valve are provided on both sides of the condenser so as to be openable and closable.

In this dryer, the intake and exhaust valves are closed to make the circulation air passage a closed air passage, and in this state, the blower fan, the heater and the condenser are operated to be dried, and the intake valve and the exhaust air are exhausted. Open the valve to make the circulation air passage an open air passage, and in this state, warm air exhaust drying operation that operates the blower fan and heater, and cold air exhaust drying operation (cool down operation) that also operates only the blower fan, In this order, the procedure is continued for a predetermined time.

In the recovery / drying operation, the circulating air blown by a blower fan is heated by a heater and introduced into a rotary drum, and the solvent contained in the material to be dried inside the rotary drum is vaporized and carried out. The vaporized solvent in the carry-out air is condensed and liquefied by contact with the condenser on the downstream side of the rotary drum to be collected. During this operation, it is important to prevent explosion accidents due to the ignition of the vaporized solvent, but in order to improve the efficiency of operation, the internal temperature of the rotating drum should be as high as possible and the evaporation should be performed at high temperature. It is necessary to vaporize.

Therefore, conventionally, thermometers for detecting the temperature of the circulating air are provided on the inlet side and outlet side of the rotary drum and on the outlet side of the condenser, respectively, and the temperature detected by these thermometers is used as the flash point of the solvent (petroleum-based). The temperature of the solvent is controlled to control the heating temperature in the heater based on the comparison result by comparing each target temperature set with reference to about 40 ° C.). As the heater, a heater of a type that generates heat by supplying steam is often used, and the heating temperature control by the heater can be performed by interrupting the supply of steam.

[0006]

However, in the circulation air passage during the recovery and drying operation performed as described above, dust such as thread waste and lint generated by the material to be dried floats. Is collected by a lint filter arranged on the upstream side of the condenser, but is arranged on each of the thermometers arranged to detect the temperature of the circulating air, particularly on the outlet side of the rotating drum. There is a high possibility that the above-mentioned dust will adhere to the thermometer, and if the operation is continued with this adhesion occurring, the temperature control of the heater will be carried out due to the incorrect detection temperature of each thermometer, and There is a disadvantage that the temperature of the introduced air is low and the drying time is prolonged, and on the contrary, the temperature of the introduced air becomes excessively high, which causes a fire explosion of the vaporized solvent.

Conventionally, when the detected temperature of each of the thermometers is abnormal as compared with that of the other thermometers, a safety measure is taken to automatically stop the recovery / drying operation. Abnormalities in the detected temperature occur not only due to malfunctions of each, but also due to malfunctions of the heater, condenser, blower fan, and lint filter arranged in the circulation air passage. There has been a problem that it takes a lot of time to identify the faulty part leading to the stop and to investigate the cause of the fault, that is, the fault diagnosis.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a recovery dryer capable of promptly diagnosing a failure that occurs during operation.

[0009]

SUMMARY OF THE INVENTION A solvent recovery type dryer according to the present invention seals a circulation air passage including a storage tank for a material to be dried washed with a solvent, a heater and a condenser, and the circulation air. The temperature of the heater is controlled based on the temperature detected by the thermometers arranged at a plurality of locations inside the passage, and the circulating air heated to a temperature close to the flash point of the solvent is introduced into the storage tank. Recovery drying operation of condensing and liquefying the vaporized solvent contained in the discharged circulating air by the condenser, and opening the middle of the circulating air passage to take in the outside air on the upstream side of the heater, and this outside air In a solvent recovery type dryer that introduces into the storage tank in a heated or non-heated state and performs an exhaust drying operation of discharging the upstream side of the condenser, the temperature detected by each of the thermometers during each operation Memorize the change pattern of Storage means that, characterized by comprising a means for performing failure diagnosis of each thermometer based on the stored pattern of the storage means.

[0010]

In the present invention, during the recovery / drying operation and the subsequent exhaust drying operation (warm air exhaust drying operation and cool down operation), the heater is placed inside the circulation air passage for heating control. The change over time in the temperature detected by each thermometer is investigated, and, for example, these change patterns are compared with their respective reference patterns, and failure diagnosis is performed in each thermometer based on the comparison result. Therefore, when the operation is stopped due to an abnormality in temperature, it is possible to determine whether or not the stop is due to an abnormality in the thermometer, and the time required for failure diagnosis is greatly shortened.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing the embodiments. 1 and 2 are operation explanatory views of the solvent recovery type dryer according to the present invention. As shown in the figure, the solvent recovery type dryer according to the present invention stores a material to be dried C that has been drained after cleaning and has a cylindrical rotary drum (storage tank) 1 that is driven to rotate around a horizontal axis. A circulating air passage 2 including the rotary drum 1 in the middle thereof is provided.

Inside the circulating air passage 2, a lint filter 5, a condenser 6, a blower fan 3 and a heater 4 are arranged in this order from the downstream side of the rotary drum 1. A storage tank 7 for the recovered solvent is removably attached below the condenser 6, and an air inlet for communicating the inside of the circulation air passage 2 with the outside air is provided between the condenser 6 and the blower fan 3 on the downstream side of the condenser 6. A is formed by an intake valve 8 so as to be openable and closable, and an exhaust port B is similarly formed between the condenser 6 and an upstream lint filter 5 by an exhaust valve 9 so as to be openable and closable.

When the intake valve 8 and the exhaust valve 9 are closed, the circulation air passage 2 becomes a closed air passage as shown in FIG.
When the blower fan 3 is driven in this state, the blower fan 3
After being introduced into the rotary drum 1 via the heater 4, the wind generated by the above-mentioned circulates along the route of returning to the blower fan 3 via the lint filter 5 and the condenser 6. On the other hand, when the intake valve 8 and the exhaust valve 9 are opened, the circulation air passage 2 becomes an open air passage communicating with the outside air on both sides of the condenser 6, as shown in FIG.
When the blower fan 3 is driven in this state, outside air is sucked into the circulation air passage 2 from the intake port A, is introduced into the rotary drum 1 via the heater 4, and is then passed through the lint filter 5 and the condenser 6 is installed. A flow is discharged from the exhaust port B without reaching the position.

The heater 4 is supplied with heating steam from a steam source (not shown), and when the steam inlet valve 4a and the steam outlet valve 4b, both of which are electromagnetic valves, are opened, the circulating air passage 2 Of the ventilation is heated by contact with the heater 4 and introduced into the rotary drum 1, while when both valves 4a and 4b are closed, the supply of steam to the heater 4 is stopped, resulting in circulation air passage. The draft in 2 is introduced into the rotating drum 1 in the unheated state. That is, the steam inlet valve 4a and the steam outlet valve 4b
The temperature of the air introduced into the rotary drum 1 can be controlled by opening and closing.

Further, the condenser 6 is provided with a water pipe through which cooling water is constantly passed, and the ventilation inside the circulating air passage 2 in a sealed state is passed when passing through the position where the condenser 6 is arranged. It is cooled by heat exchange with the cooling water, and at this time, the vaporized solvent contained in the ventilation is condensed and liquefied, and is dropped into the storage tank 7 and recovered.

Inside the circulating air passage 2 on the inlet side and outlet side of the rotary drum 1 and on the outlet side of the condenser 6, a drum inlet side thermometer 11 for detecting the temperature of the circulating air at the respective positions and A drum outlet side thermometer 12 and a condenser outlet side thermometer 13 are provided, respectively. A thermistor is used as each of these thermometers 11, 12, and 13.

FIG. 3 is a block diagram of a control system which controls the operation of the solvent recovery type dryer according to the present invention. In the figure, 10 is a control unit using a microprocessor.
The input side of the drum has a drum-side thermometer arranged as described above.
11, from the drum outlet side thermometer 12 and the condenser outlet side thermometer 13,
An output signal corresponding to each detected temperature is given, and an on / off signal of a door switch 14 interlocked with opening and closing of the front door of the rotary drum 1 is given, and further, an operation panel 20 as shown in FIG. The operation results of various key switches arranged above, that is, the operation start switch 21, the operation stop switch 22, the temperature selection switch 23, and the temperature call switch 24 are given.

On the other hand, the output of the control unit 10 is an electromagnetic switch 1b and an electromagnetic switch 1b provided between the drum motor 1a for driving the rotary drum 1 and the fan motor 3a for driving the blower fan 3 and the commercial power source. An intake valve 8 and an exhaust valve 9 for opening and closing the circulation air passage 2, and a steam inlet valve 4a and a steam outlet valve 4b to the heater 4, respectively, are provided to the switch 3b, and the operation panel 20 is further provided. Various display units arranged above, that is, the operating time display unit 25, the process display unit 26, and the temperature display unit 27.
Is given to.

In the solvent recovery type dryer according to the present invention constructed as described above, the intake valve 8 and the exhaust valve 9 are closed to seal the circulation air passage 2, and the blower fan 3, the heater 4 and the condenser 6 are connected. Recovery and drying operation performed together with the intake valve 8
And, the exhaust valve 9 is opened to open the circulation air passage 2 and the blower fan 3 and the heater 4 are operated to perform the warm air exhaust drying operation, and similarly, only the blower fan 3 is operated to perform the cool air exhaust drying operation ( Cool-down operation) is possible. Generally, each of these is operated in a mode that continues for a predetermined time, but the recovery drying operation is omitted, the mode in which only the exhaust drying operation is performed, and the recovery drying operation and the warm air exhaust drying operation are omitted, Various operation modes such as a mode for performing only the cool-down operation can be selected, and the operator can set a desired operation mode by operating the operation start switch 21 on the operation panel 20.

The control unit 10 includes an operation start switch 21
The operation is started in response to the ON operation of, the closing command is issued to the electromagnetic switches 1b and 3b, and the rotary drum 1 and the blower fan 3 are driven by supplying power to the drum drive motor 1a and the fan drive motor 3a. The operation mode set by the operation of the operation start switch 21 is confirmed, and one of the recovery / drying operation, the warm air exhaust drying operation and the cool down operation is performed, and each processing is performed.

In the recovery / drying operation, the control unit 10 issues a close command to the intake valve 8 and the exhaust valve 9 to keep the circulating air passage 2 in a hermetically closed state and operate the heater 4. As a result, the circulating air generated by the blower fan 3 follows the path of returning to the blower fan 3 through the heater 4, the rotating drum 1, the lint filter 5, and the condenser 6 in this order. At this time, the solvent remaining on the material to be dried C in the rotary drum 1 is
Contact with hot air heated by contact with the air, evaporate into the hot air and carry it out, and after lint filter 5 removes dust such as lint and lint, it contacts with condenser 6 to condense and liquefy Then, it is dropped into the storage tank 7 and collected.

During this time, the control unit 10 keeps the drum entrance side thermometer.
11, the drum output side thermometer 12, and the condenser output side thermometer 13 detected temperature is taken in at a predetermined sampling period, these detected temperatures are compared with respective different target temperatures, and based on this comparison result. An opening / closing command is issued to the steam inlet valve 4a and the steam outlet valve 4b, and a temperature control operation is performed to adjust the heating degree of the heater 4 by cutting off the supply of steam. The target temperature on the outlet side of the rotary drum 1 is set with reference to the flash point of the solvent used for cleaning the material to be dried C, and the target temperature on the inlet side of the rotary drum 1 is set to the target temperature in the rotary drum 1. The temperature drop caused by heat exchange with the dried product C is set higher than the target temperature on the outlet side. For example, when using a petroleum-based solvent, the target temperature on the outlet side is around 41 ° C and the target temperature on the inlet side is 44 (= 41
It is set around +3) ° C.

As a result, hot air having a temperature extremely close to the flash point of the solvent is introduced into the rotary drum 1, so that the solvent from the material to be dried C is vaporized and vaporized satisfactorily. The recovery / drying operation can be promptly ended without fear. The temperature detected by the condenser outlet side thermometer 13 is used for determining the abnormality of the condenser 6 during the recovery / drying operation.

On the other hand, in the hot air exhaust drying operation, the control unit 10
Issues an opening command to the intake valve 8 and the exhaust valve 9, causing the circulation air passage 2
As an open air passage and the steam inlet valve 4a and steam outlet valve
An opening command is issued to 4b to put the heater 4 into a continuous heating state.

In this case, the outside air sucked from the suction port A by the operation of the blower fan 3 becomes hot hot air by contact with the heater 4 and is introduced into the rotary drum 1 and remains on the article C to be dried. The solvent is vaporized and carried out, passes through the lint filter 5 to trap dust, and is then discharged to the outside air through the exhaust port B. At this time, the hot air introduced into the rotary drum 1 has a temperature sufficiently higher than the flash point of the solvent, but since the material to be dried C is in a state of being dried to some extent and the concentration of the vaporized solvent is low, the ignition temperature is high. There is no danger of explosion.

Further, in the cool down operation, the control unit 10
Issues an opening command to the intake valve 8 and the exhaust valve 9, causing the circulation air passage 2
As an open air passage and the steam inlet valve 4a and steam outlet valve
A closing command is issued to 4b to put the heater 4 into a non-heated state.

In this case, the outside air sucked from the suction port A by the operation of the blower fan 3 is introduced into the rotary drum 1 while keeping the temperature as it is, and the lint filter 5 and the exhaust port B are provided.
Is discharged to the outside air. At this time, in the inside of the rotating drum 1, the material to be dried C, which has become hot due to the hot air exhaust drying operation, is cooled by contact with the low-temperature introduced air, and can be safely taken out from the rotating drum 1. It will be possible.

Even during the hot air exhaust drying operation and the cool down operation as described above, the drum entrance side thermometer by the control unit 10
11, the drum outlet side thermometer 12 and the condenser outlet side thermometer 13 continue to take in the detected temperatures, and the respective detected temperatures at each sampling time are the temperature pattern storage unit built in the control unit 10. Sequentially stored in 10a. On the other hand, the control unit 10
Includes a reference pattern storage unit 10b. The reference pattern storage unit 10b includes a drum inlet side thermometer in each of the recovery / drying operation, the exhaust drying operation, and the cooldown operation.
Desired change patterns (reference patterns) of temperature changes with time at the positions where 11, the drum outlet side thermometer 12, and the condenser outlet side thermometer 13 are arranged are stored in advance.

In the control unit 10, the temperature pattern storage unit
Comparison between 10a and the reference pattern storage unit 10b, that is,
A temperature pattern obtained during actual operation is compared with a reference pattern, and based on the comparison result, each of the thermometers, that is, the drum inlet side thermometer 11, the drum outlet side thermometer 12, and the condenser outlet side. A failure diagnosis of the thermometer 13 is performed.

FIG. 5 is an explanatory view of the method of the failure diagnosis, and the solid line and the broken line in the figure show examples of reference patterns on the inlet side and the outlet side of the rotary drum 1, respectively. Furthermore, the alternate long and short dash line in the figure shows the detected temperature pattern of the drum outlet side thermometer 12 under the condition where lint, lint, etc. adhere to the periphery, and this pattern is clearly the reference pattern shown by the broken line. different. This is because the attachment speed of the lint and lint increases the sensitive speed of the thermistor used as the drum outlet side thermometer 12 and impairs the temperature detection following the actual change. As described above, the presence / absence of a failure of the drum outlet side thermometer 12 can be reliably determined by comparing the detected temperature pattern and the reference pattern. Similarly, failure diagnosis of the drum inlet side thermometer 11 or the condenser outlet side thermometer 13 can also be performed by comparing the temperature patterns detected by these with the respective reference patterns.

When the control unit 10 determines that there is a failure by the failure diagnosis of the thermometer performed as described above, the control unit 10 outputs to the buzzer 15 and causes the buzzer 15 to ring to determine the temperature. Informs that a failure has occurred in the meter,
Furthermore, a predetermined output is issued to the operation panel 20, and the temperature display unit 27
A predetermined display is displayed above to notify which of the drum inlet side thermometer 11, the drum outlet side thermometer 12, and the condenser outlet side thermometer 13 has a failure.

The operation of the temperature selection switch 23 and the temperature call switch 24 on the operation panel 20 is performed by the temperature pattern storage unit 10a.
It is used to call up the detected temperature pattern stored in.
The temperature selection switch 23 is used for selecting which of the thermometers of the drum inlet side thermometer 11, the drum outlet side thermometer 12, and the condenser outlet side thermometer 13 to call the detected temperature pattern. The drum entrance side thermometer 11 is operated by one operation of the selection switch 23, and the drum exit side thermometer 12 is operated by two operations.
However, the condenser outlet-side thermometer 13 is selected by three operations, and the selection contents are displayed on the temperature display unit 27 on the operation panel 20. Also, the temperature call switch 24
Is used to call the stored value of the detected temperature by the designated thermometer, and the control unit 10 sequentially outputs the stored value of the temperature pattern storage unit 10a each time the temperature calling switch 24 is operated,
The temperature display unit 27 on the operation panel 20 is operated to display the temperature.

That is, when the thermometer is selected by the temperature selection switch 23 and the operation of the temperature calling switch 24 is repeated,
On the temperature display unit 27, the detected temperature detected by the selected thermometer at predetermined time intervals from the start of operation will be sequentially displayed, and the user can visually check the displayed contents to see each of the thermometers. The failure of 11, 12, 13 can be known at an early stage. In the present embodiment, the temperature display unit 27 is configured to display numerical values, but it is also possible to display a graph as shown in FIG.
2 and 13 early failure diagnosis can be performed more reliably.

[0034]

As described above in detail, in the solvent recovery type dryer according to the present invention, the temperature detected by each thermometer disposed inside the circulation air passage for controlling the heating of the heater during the drying operation. Since the failure diagnosis of each thermometer is performed based on the change pattern over time, when the operation is stopped due to an abnormal temperature, it is promptly judged whether this stop is due to the abnormality of the thermometer and the cause of failure is determined. Investigation, identification of faulty part, etc.
The present invention has excellent effects such as a drastic reduction in the time required for failure diagnosis.

[Brief description of drawings]

FIG. 1 is an operation explanatory view of a solvent recovery type dryer according to the present invention.

FIG. 2 is an operation explanatory view of the solvent recovery type dryer according to the present invention.

FIG. 3 is a block diagram of a control system of the solvent recovery dryer according to the present invention.

FIG. 4 is a plan view showing an example of an operation panel of the solvent recovery type dryer according to the present invention.

FIG. 5 is an explanatory diagram of a method of failure diagnosis of a thermometer.

[Explanation of symbols]

 1 rotating drum 2 circulating air duct 4 heater 6 condenser 8 intake valve 9 exhaust valve 10 control unit 10a temperature pattern storage unit 10b reference pattern storage unit 11 drum inlet side thermometer 12 drum outlet side thermometer 13 condenser outlet side thermometer 20 Operation panel 23 Temperature select switch 24 Temperature call switch

Claims (1)

[Claims] 1. A closed air passage including a storage tank for a material to be dried washed with a solvent, a heater and a condenser,
The temperature of the heater is controlled based on the temperature detected by thermometers arranged at a plurality of positions inside the circulation air passage, and the circulation air heated to a temperature close to the flash point of the solvent is introduced into the storage tank, A collecting and drying operation in which the vaporized solvent contained in the circulating air drawn out from the storage tank is condensed and liquefied by the condenser and collected, and the middle of the circulating air passage is opened to take in the outside air on the upstream side of the heater. In a solvent recovery type dryer that introduces this outside air into the storage tank in a heated or non-heated state, and performs an exhaust drying operation to discharge it on the upstream side of the condenser,
A storage unit for storing a temporal change pattern of the detected temperature of each of the thermometers during each operation; and a unit for diagnosing a failure of each thermometer based on the storage pattern of the storage unit. Solvent recovery dryer.