US20080115540A1 - Dry cleaner - Google Patents
Dry cleaner Download PDFInfo
- Publication number
- US20080115540A1 US20080115540A1 US11/984,148 US98414807A US2008115540A1 US 20080115540 A1 US20080115540 A1 US 20080115540A1 US 98414807 A US98414807 A US 98414807A US 2008115540 A1 US2008115540 A1 US 2008115540A1
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- US
- United States
- Prior art keywords
- steam
- solvent
- valve
- dry cleaner
- switch
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000001035 drying Methods 0.000 claims abstract description 66
- 239000002904 solvent Substances 0.000 claims description 144
- 239000007788 liquid Substances 0.000 claims description 36
- 238000010438 heat treatment Methods 0.000 claims description 29
- 238000000034 method Methods 0.000 claims description 21
- 238000005406 washing Methods 0.000 claims description 13
- 238000005259 measurement Methods 0.000 claims description 7
- 238000010412 laundry washing Methods 0.000 claims description 2
- 238000001514 detection method Methods 0.000 abstract description 19
- 239000002826 coolant Substances 0.000 description 14
- 230000001276 controlling effect Effects 0.000 description 13
- 239000000344 soap Substances 0.000 description 11
- 238000004880 explosion Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 7
- 238000007710 freezing Methods 0.000 description 7
- 230000008014 freezing Effects 0.000 description 7
- 238000010276 construction Methods 0.000 description 6
- 238000011084 recovery Methods 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 238000009834 vaporization Methods 0.000 description 4
- 230000008016 vaporization Effects 0.000 description 4
- 238000005108 dry cleaning Methods 0.000 description 3
- 239000003208 petroleum Substances 0.000 description 3
- 230000001105 regulatory effect Effects 0.000 description 3
- 230000007257 malfunction Effects 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 238000005202 decontamination Methods 0.000 description 1
- 230000003588 decontaminative effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 239000013557 residual solvent Substances 0.000 description 1
Images
Classifications
-
- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
- D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
- D06F43/00—Dry-cleaning apparatus or methods using volatile solvents
Definitions
- the present invention relates to a dry cleaner and, more specifically, to a dry cleaner which performs a washing process employing a flammable solvent, a liquid removing process and a drying process.
- Dry cleaners are conventionally known, which are adapted to wash laundry with a flammable solvent such as a petroleum-based solvent, remove the solvent from the washed laundry, and dry the laundry by applying hot air heated by a heater to the laundry for vaporization of the solvent.
- a flammable solvent such as a petroleum-based solvent
- the petroleum-based solvent is highly flammable. Therefore, if solvent gas resulting from the vaporization of the solvent from the laundry is present at a higher concentration during the drying of the laundry, the solvent gas is liable to be ignited by the heat of the heater, resulting in momentary flash or explosion.
- a known dry cleaner designed to prevent such accidents includes: a drum in which laundry is contained, and a washing process, a liquid removing process and a drying process are performed; an air circulation duct through which air is circulated to the drum; a drying heater of a steam heating type for heating the air flowing through the air circulation duct; a steam valve which is opened and closed for supplying steam to the drying heater; a drum inlet temperature sensor provided in the air circulation duct for measuring the temperature of gas to be supplied to the drum; a drum outlet temperature sensor which measures the temperature of gas having passed through the drum; and a control section including a microcomputer and the like for controlling the steam valve and the temperature sensors (see, for example, Japanese Unexamined Patent Publication No. 2005-218881).
- a drum outlet temperature is changed according to the amount of solvent contained in the laundry. That is, if the laundry contains a greater amount of solvent, the amount of solvent vaporized from the laundry is relatively great, so that the drum outlet temperature is relatively low. If a drum inlet temperature is elevated, for example, by promoting the heating with the steam valve being opened when the drum outlet temperature is lower, the solvent vaporization amount is further increased. If an atmosphere containing the solvent gas at a concentration higher than a safety value (e.g., 6.0 vol % where the solvent is gasoline No. 5) occurs in the drum, there is the danger of ignition.
- a safety value e.g., 6.0 vol % where the solvent is gasoline No. 5
- the microcomputer monitors the drum outlet temperature and controls the opening and closing of the steam valve to control the temperature of the circulation air supplied from a drum inlet, thereby preventing an excessive increase in the amount of the solvent vaporized from the laundry and hence preventing the solvent gas concentration from exceeding the safety value for elimination of the danger.
- It is still another object of the present invention is to provide a safety circuit for a dry cleaner.
- a dry cleaner which performs a laundry washing process employing a flammable solvent, a liquid removing process and a drying process, and includes: a treatment tub in which laundry is contained, and the washing process, the liquid removing process and the drying process are performed; an air circulation duct through which air taken out of the treatment tub flows back to the treatment tub in a closed flow circuit in the drying process; heating unit which heats the air flowing through the air circulation duct; controller which controls operation of the heating unit to perform the drying process; signal outputting unit which outputs a termination signal in response to completion of a predetermined liquid removing operation performed in the treatment tub; and a safety circuit which maintains the heating unit in an inactive state irrespective of a control status of the controller unless the termination signal is outputted.
- the treatment tub may include a liquid-tight outer tub, an inner tub rotatably provided in the outer tub and configured to be rotated to remove the solvent from the laundry contained therein by a centrifugal force, and a drive motor which rotates the inner tub.
- the signal outputting unit may include a mechanism which outputs the termination signal after the inner tub or the drive motor is rotated at a rotation speed not lower than a predetermined rotation speed level for a predetermined rotation period.
- the signal outputting unit may include a switch which is turned on when the rotation speed of the inner tub or the drive motor is not less than the predetermined rotation speed level, and a timer which starts time measurement in response to the turn-on of the switch to measure a switch turn-on time during which the switch is turned on and, when the switch turn-on time reaches a predetermined period, outputs the termination signal.
- the heating unit may include a heat exchanger which exchanges heat with the air flowing through the air circulation duct, and steam supplying unit which supplies steam to the heat exchanger.
- the safety circuit may be configured to prevent the steam from being supplied from the steam supplying unit to the heat exchanger to maintain the heating unit in the inactive state.
- the steam supplying unit may include a steam supplying passage through which the steam is supplied, and a valve which opens and closes the steam supplying passage.
- the safety circuit may be configured to constantly close the valve to maintain the heating unit in the inactive state.
- the steam supplying passage may include a plurality of steam supplying passages, and valves may be respectively disposed in the steam supplying passages.
- the safety circuit may be configured to constantly close a predetermined one of the valves to maintain the heating unit in the inactive state.
- the heating unit is maintained in the inactive state by the safety circuit irrespective of the control status of the controller unless the termination signal is outputted by the signal outputting unit in response to the completion of the predetermined liquid removing operation performed in the treatment tub.
- the signal outputting unit is configured as a hardware component separate from the controller (a microcomputer and the like) and, therefore, provides the termination signal independently of the controller. Thus, actuation of the heating unit is permitted only after the completion of the predetermined liquid removing operation.
- the solvent gas concentration during the drying process is heavily dependent upon the amount of the solvent contained in the laundry and the temperature of the air applied to the laundry. Therefore, the solvent gas concentration is liable to be increased, as the contained solvent amount and the air temperature are increased.
- the amount of the solvent contained in the laundry is reduced and, even if the air temperature is high, there is no possibility that the solvent gas concentration is increased to a predetermined concentration level or higher.
- an amount “A” of the solvent contained in the laundry is herein defined such that, even if laundry containing the solvent in an amount not greater than the solvent amount “A” is overheated, the solvent gas concentration is maintained at a level not greater than 0.8 vol % (in the following description, “A” is the solvent amount thus defined, unless otherwise specified).
- the predetermined liquid removing operation according to the present invention is defined as a liquid removing operation to be performed so as to reduce the amount of the solvent contained in the laundry to a level not greater than “A”
- the actuation of the heating unit is permitted only after the amount of the solvent contained in the laundry is reduced to the level not greater than “A”.
- the controller runs away when the heating unit is in an active state, e.g., if the heating unit is brought into an uncontrollable state to overheat the air in the air circulation duct, there is no possibility that the solvent gas concentration exceeds the flammable lower limit concentration, because the amount of the solvent contained in the laundry is not greater than “A”. This ensures the safety in the drying process.
- the dry cleaner is highly safe without the danger of the ignition and the like.
- the signal outputting unit includes the mechanism which outputs the termination signal after the inner tub or the driving motor is rotated at a rotation speed not lower than the predetermined rotation speed level for the predetermined rotation period.
- the predetermined rotation speed level and the predetermined rotation period are respectively defined as a rotation speed and a rotation period which ensure that the amount of the solvent contained in the laundry after the liquid removing process can be reduced to a level not greater than “A”
- the solvent gas concentration is prevented from being increased to the predetermined concentration level or higher by a simple method, i.e., by detecting the rotation speed of the inner tub and the rotation period.
- the signal outputting unit includes the switch which is turned on when the rotation speed of the inner tub or the drive motor is not lower than the predetermined rotation speed level, and the timer which starts the time measurement in response to the turn-on of the switch to measure the switch turn-on time and, when the switch turn-on time reaches the predetermined period, outputs the termination signal. Therefore, the solvent gas concentration is prevented from being increased to the predetermined concentration level or higher by a simple method, i.e., by controlling the switch and the timer.
- the heating unit includes the heat exchanger which exchanges heat with the air flowing through the air circulation duct, and the steam supplying unit which supplies steam to the heat exchanger. Further, the supply of the steam from the steam supplying unit to the heat exchanger is prevented by the safety circuit to maintain the heating unit in the inactive state. Thus, the steam is supplied to the heat exchanger to heat the air flowing through the air circulation duct only after the completion of the predetermined liquid removing operation.
- the controller runs away during the supply of the steam, e.g., if a great amount of steam is supplied from the steam supplying unit to steeply increase the temperature of the heat exchanger, the solvent gas concentration is prevented from being increased to the predetermined concentration level or higher, because the amount of the solvent contained in the laundry is not greater than “A”.
- the steam supplying unit includes the steam supplying passage through which the steam is supplied, and the valve which opens and closes the steam supplying passage. Further, the valve is constantly closed by the safety circuit. With this arrangement, the solvent gas concentration is prevented from being increased to the predetermined concentration level or higher by a simple control operation, i.e., by constantly closing the valve.
- the steam supplying passage includes the plurality of steam supplying passages, and the valves are respectively disposed in the steam supplying passages.
- the predetermined one of the valves is constantly closed by the safety circuit.
- the predetermined one of the valves may be defined as a valve which possibly increases the solvent gas concentration to a level higher than the flammable lower limit concentration when being opened. In this case, the solvent gas concentration is prevented from being increased to the predetermined concentration level or higher by constantly closing the thus defined valve. Further, there is no need to maintain the other valves in an inactive state by the safety circuit. This obviates the need for providing an additional device, thereby saving costs.
- FIG. 1 is a front perspective view of major portions of a dry cleaner according to one embodiment of the present invention.
- FIG. 2 is a pipeline diagram of the dry cleaner shown in FIG. 1 .
- FIG. 3 is a block diagram illustrating the electrical construction of the dry cleaner shown in FIG. 1 , particularly showing components related to the present invention.
- FIG. 4 is a diagram illustrating a relay sequence controlling circuit which constitutes a solvent gas concentration safety system.
- FIG. 1 is a front perspective view of major portions of a dry cleaner 1 according to one embodiment of the present invention. Reference will be made to directional arrows shown in FIG. 1 for directional notation.
- the dry cleaner 1 is, for example, for business use, and includes a generally rectangular box-shaped main body 2 , and a tank/filter kit 3 (see FIG. 2 ).
- the main body 2 includes a rack-like frame 2 a .
- An outer tub 4 and a drum 5 (inner tub) accommodated in the outer tub 4 are provided within the frame 2 a .
- the frame 2 a is fixed to a floor.
- An operation panel 2 b is attached to a front face portion of the frame 2 a above the outer tub 4 , specifically, at around a level of user's eyes.
- a user operates operation buttons 66 (to be described later) of the operation panel 2 b to cause the dry cleaner 1 to perform desired operations by, and the operation status of the dry cleaner 1 is displayed on a display panel 67 (to be described later) of the operation panel 2 b.
- the outer tub 4 is of a generally rectangular box shape, and has a generally cylindrical space defined therein.
- the outer tub 4 has an outer tub opening 4 a formed in a front wall thereof as communicating with the inside thereof and having a round shape as seen from the front side.
- An annular metal rim 4 b is fitted along the periphery of the outer tub opening 4 a .
- An annular packing 4 c is attached to an inner peripheral front edge of the rim 4 b .
- the rim 4 b has a hinge 4 d provided at a left edge portion thereof, and an engagement projection 4 e provided at a right edge portion thereof.
- a door (not shown) is attached to the hinge 4 d so as to be pivotal about a pivot shaft of the hinge 4 d to open and close the outer tub opening 4 a .
- the door (not shown) has an engagement projection (not shown) provided at a portion thereof opposite from the hinge side.
- the engagement projection (not shown) of the door is engaged with the engagement projection 4 e of the rim 4 b , whereby the door (not shown) is locked with the outer tub opening 4 a closed.
- the drum 5 has a generally cylindrical hollow shape, and is disposed with its center shaft extending generally horizontally, specifically, extending anteroposteriorly.
- a drum motor 21 (see FIG. 3 ) connected to the center shaft of the drum 5 is disposed behind the drum 5 .
- a driving force generated by rotation of the drum motor 21 is transmitted to the drum 5 through the center shaft to rotate the drum 5 .
- the drum 5 has a drum opening 5 a formed in a front wall thereof at a position corresponding to the outer tub opening 4 a as communicating with the inside of the drum 5 .
- the drum opening 5 a is anteroposteriorly opposed to the outer tub opening 4 a .
- a plurality of baffles 5 b are provided on an inner peripheral surface of the drum 5 as projecting toward the center shaft.
- FIG. 2 is a pipeline diagram of the dry cleaner 1 .
- the internal construction of the dry cleaner 1 will hereinafter be described in detail.
- the outer tub 4 has an air inlet 6 through which air is introduced into the drum 5 , and an air outlet 7 through which the air is expelled from the drum 5 .
- the air outlet 7 and the air inlet 6 are connected to each other through a circulation duct 8 (air circulation duct). That is, the circulation duct 8 is regarded as a closed circuit (closed flow circuit) which has the air inlet 6 and the air outlet 7 and connects the air outlet 7 and the air inlet 6 to each other.
- the dry cleaner 1 is an apparatus designed to perform a dry cleaning process with the use of a special flammable solvent (e.g., a petroleum-based solvent or the like).
- a special flammable solvent e.g., a petroleum-based solvent or the like.
- the dry cleaning process is advantageous in that laundry is less liable to shrink and oil stains are more easily removed as compared with a water cleaning process in which the laundry is washed with water.
- the dry cleaner according to this embodiment is of a type which is adapted to recover all the used solvent.
- a predetermined amount of solvent supplied from a tank 31 to be described later is contained in the outer tub 4 , and the laundry is washed with the solvent in a washing process.
- the solvent is recovered from the outer tub 4 into the tank 31 .
- the drum 5 is rotated at a higher speed to remove residual solvent from the laundry.
- the removed solvent is also recovered into the tank 31 .
- a drying process is performed to dry the laundry by circulating the air between the circulation duct 8 and the drum 5 while rotating the drum 5 at a lower speed.
- the vapor of the solvent resulting from vaporization of the solvent from the laundry in the drying process is also recovered by condensation thereof.
- the laundry is agitated by the baffles 5 b .
- the laundry is efficiently washed and dried.
- a blower 10 is rotated by a blower motor 9 , whereby the air in the drum 5 is circulated from the air outlet 7 into the air inlet 6 through the circulation duct 8 .
- Drying coolers 11 and 12 are provided in the circulation duct 8 , and a drying heater 13 (heat exchanger) is provided adjacent the air inlet 6 .
- the air flowing out of the drum 5 into the circulation duct 8 through the air outlet 7 contains the vaporized solvent (solvent gas).
- the air containing the solvent gas is cooled by the drying coolers 11 and 12 , so that the solvent gas in the air is liquefied.
- the solvent-containing air flowing through the circulation duct 8 is cooled by the drying coolers 11 and 12 , whereby the solvent is condensed and recovered from the air. Thereafter, the air is heated by the drying heater 13 , and the heated air is supplied as drying air into the drum 5 through the air inlet 6 . In the drum 5 , the heated air is heat-exchanged with the laundry, whereby the solvent contained in the laundry is vaporized. The vaporized solvent flows together with the air into the circulation duct 8 through the air outlet 7 . This cycle in which the air is circulated between the drum 5 and the circulation duct 8 is repeated, thereby drying the laundry in the drum 5 .
- the dry cleaner 1 is configured such that the drying air from the air inlet 6 is supplied to the laundry in the drum 5 through the outer tub opening 4 a and the drum opening 5 a .
- the drum opening 5 a is an opening having the greatest size in the drum 5 , so that the drying air can be efficiently supplied to the laundry through the drum opening 5 a .
- the air in the drum 5 is circulated through the circulation duct 8 . Therefore, the air heated by the drying heater 13 and supplied into the drum 5 is heat-exchanged with the laundry in the drum 5 to vaporize moisture (solvent) from the laundry, and then reused for the drying of the laundry rather than being expelled together with the vaporized moisture to the outside. Accordingly, the dry cleaner 1 is environmentally friendly.
- the solvent is flammable. Therefore, there is the danger of ignition or explosion of the vaporized solvent unless the temperature of the heated air is reliably controlled in the drying process.
- a drum inlet temperature thermistor 14 and an inlet over-temperature preventing thermistor 15 are provided downstream of the drying heater 13 (on a downstream side with respect to an air flow direction—this definition holds true for the following description) in the circulation duct 8 .
- the inlet over-temperature preventing thermistor 15 is connected to a transistor circuit, and configured such that the circuit is cut off through the transistor, for example, when a temperature of 95° C. is detected. Therefore, the inlet over-temperature preventing thermistor 15 is advantageous in that it ensures more accurate detection of an operation temperature and a quicker response to the temperature than a thermostat.
- a drum outlet temperature thermistor 16 and an abnormal outlet temperature judging thermistor 17 which monitors the drum outlet temperature thermistor 16 to check whether or not the drum outlet temperature thermistor 16 malfunctions are provided in the circulation duct 8 .
- a cooler temperature thermistor 18 and a cooler over-temperature preventing thermistor 19 which constitutes a part of a safety circuit are provided in the circulation duct 8 .
- an aspiration port 20 and a gate valve V 14 are provided between the drying cooler 12 and the drying heater 13 in the circulation duct 8 for regulating the internal pressure of the circulation duct 8 when the circulation duct internal pressure is excessively increased.
- the aspiration port 20 is opened, and the gate valve V 14 is opened to permit the air to flow through the circulation duct 8 .
- the circulation duct 8 has an explosion protection port 26 which, if the solvent gas-containing air flowing through the circulation duct 8 happens to be ignited to cause explosion, releases the blast of the explosion.
- the explosion protection port 26 is biased in a closing direction by a spring not shown.
- the drying coolers 11 and 12 are connected to a freezing machine 23 through coolant passages 22 a , 22 b and 22 c .
- the freezing machine 23 is disposed outside the main body 2 .
- a drying cooler electromagnetic valve 2 Y inserted in the coolant passage 22 a is opened, a coolant (e.g., cooling water) flows from the freezing machine 23 into the drying cooler 12 and the drying cooler 11 through the coolant passages 22 a and 22 b , whereby the drying cooler 12 and the drying cooler 11 perform a cooling operation.
- the drying coolers 11 and 12 are herein connected in series with each other to the freezing machine 23 , but may be connected in parallel with each other to the freezing machine 23 .
- the coolant passages 22 a and 22 c may be provided for each of the drying coolers 11 and 12 to supply the coolant individually to the drying coolers 11 and 12 from the freezing machine 23 .
- freezing machines 23 may be respectively provided for the drying coolers 11 and 12 .
- the drying heater 13 is a so-called radiator which radiates heat of steam passing therethrough from fins thereof to heat the ambient atmosphere, and is connected to a steam passage 24 (steam supply passage) and a steam passage 25 . More specifically, the steam passage 24 connects an external steam source to the drying heater 13 .
- An inlet valve V 20 is inserted in the steam passage 24 .
- the steam passage 24 is branched into a first steam supply passage 24 a having a relatively great passage diameter and a second steam supply passage 24 b having a relatively small passage diameter between the drying heater 13 and the inlet valve V 20 .
- a first valve V 27 is inserted in the first steam supply passage 24 a
- a second valve V 28 is inserted in the second steam supply passage 24 b .
- a path extending from the steam passage 24 to the drying heater 13 corresponds to the heating unit according to the present invention.
- the steam passage 25 is a passage through which the steam supplied from the steam passage 24 to the drying heater 13 is expelled to the outside.
- steam e.g., steam at 110 to 120° C.
- the drying heater 13 heats the air in the circulation duct 8 by the steam. Since the first steam supply passage 24 a and the second steam supply passage 24 b are different in steam supply capacity, the steam may be supplied to the drying heater 13 from one or both of the first steam supply passage 24 a and the second steam supply passage 24 b as required.
- a safety circuit 70 (to be described later) is constituted by an electric circuit which controls the opening and closing of the first valve V 27 and the second valve V 28 for prevention of the ignition and explosion of the solvent gas.
- the electric circuit for controlling the opening and closing of the valves V 27 , V 28 will be described in detail later.
- the tank/filter kit 3 includes the tank 31 which stores the solvent, and a first filter 32 and a second filter 33 which are connected in series for filtering the solvent pumped up from the tank 31 .
- a pump-up pipe 34 is connected to a bottom of the tank 31 at one end thereof.
- a valve V 1 is inserted in the pump-up pipe 34 .
- the other end of the pump-up pipe 34 is connected to a junction 35 .
- a solvent pump 36 is connected to the junction 35 on its suction side and to an inlet of a three-way valve V 6 on its ejection side.
- One outlet of the three-way valve V 6 is connected to one end of a flow pipe 37 , and the other end of the flow pipe 37 is connected to the tank 31 via a valve V 19 .
- the flow pipe 37 is branched at its intermediate portion (between the three-way valve V 6 and the valve V 19 ) to be connected to the serial connection of the first filter 32 and the second filter 33 .
- a flow pipe 38 is connected to an outlet of the second filter 33 , and a distal end of the flow pipe 38 is connected to an inlet of a solvent heat exchanger 39 provided in the main body 2 .
- a bypass pipe 40 is connected to the other outlet of the three-way valve V 6 at one end thereof, and the other end of the bypass pipe 40 joins the flow pipe 38 connected to the inlet of the solvent heat exchanger 39 .
- the solvent is applied to the solvent heat exchanger 39 through the first filter 32 and the second filter 33 , or applied to the solvent heat exchanger 39 through the bypass pipe 40 with the filters 32 and 33 bypassed by switching between the outlets of the three-way valve V 6 .
- a steam pipe 41 and a coolant pipe 42 are provided in the solvent heat exchanger 39 .
- the steam pipe 41 and the coolant pipe 42 are each wound, for example, in a coil shape.
- Steam passages 43 and 44 are connected to the steam pipe 41 .
- the steam passage 43 connects the steam pipe 41 and the steam passage 24 , and a valve V 21 is inserted in the steam passage 43 .
- the steam passage 44 is a passage through which the steam supplied from the steam passage 43 to the steam pipe 41 is discharged to the outside. With the valve V 21 being opened, the steam flows into the steam pipe 41 through the steam passage 43 to be discharged through the steam passage 44 .
- the steam pipe 41 at a high temperature exchanges heat with the solvent to heat the solvent.
- coolant passages 45 a and 45 b are connected to the coolant pipe 42 , and a solvent cooler electromagnetic valve 3 Y is inserted in the coolant passage 45 a . With the solvent cooler electromagnetic valve 3 Y being opened, the coolant passes through the coolant pipe 42 . While the solvent passes through the solvent heat exchanger 39 , the coolant pipe 42 exchanges heat with the solvent to cool the solvent.
- the solvent heat exchanger 39 is switched to heat or cool the solvent, whereby the temperature of the solvent passing through the solvent heat exchanger 39 is regulated at a desired temperature level.
- a flow pipe 46 is connected to an outlet of the solvent heat exchanger 39 at one end thereof. The other end of the flow pipe 46 is connected to an inlet of a three-way valve V 9 .
- a liquid temperature thermistor 47 for measuring the temperature of the solvent and a liquid over-temperature preventing thermistor 48 for preventing a liquid temperature from being increased to a predetermined temperature level or higher are provided in the flow pipe 46 .
- a soap concentration sensor 50 is provided downstream of these two thermistors in the flow pipe 46 .
- a liquid supply pipe 51 is connected to one outlet of the three-way valve V 9 at one end thereof and to the outer tub 4 at the other end thereof, so that the solvent can be supplied into the drum 5 .
- a feedback pipe 52 is connected to the other outlet of the three-way valve V 9 at one end thereof and to the tank 31 at the other end thereof.
- a recovery pipe 62 for recovering the solvent condensed by the drying coolers 11 and 12 in the circulation duct 8 has one end connected to a potion of the circulation duct 8 below the drying coolers 11 and 12 .
- the other end of the recovery pipe 62 is connected to a water separator 63 .
- water separator 63 water contained in the recovered solvent is separated, and the separated water is drained through a drain pipe 64 . Then, the recovered solvent is returned into the tank 31 through a recovery pipe 65 .
- the outer tub 4 has a drain port 55 provided at its lowermost portion, and a liquid surface detection chamber 56 is connected to the drain port 55 .
- the liquid surface detection chamber 56 is provided with two liquid surface switches, i.e., a standard liquid surface switch 57 and a drain liquid surface switch 58 .
- the liquid surface detection chamber 56 also serves as a trap which traps a button or the like dislodged from the laundry and falling through the drain port 55 during the washing process.
- a recovery pipe 59 is connected to a lower end of the liquid surface detection chamber 56 at one end thereof.
- a valve V 4 is inserted in the recovery pipe 59 .
- the other end of the recovery pipe 59 is connected to the junction 35 .
- a soap pipe 61 is connected to a soap container 60 at one end thereof and to the junction 35 at the other end thereof.
- a valve V 17 is inserted in the soap pipe 61 .
- the solvent stored in the tank 31 is supplied into the drum 5 (the outer tub 4 ).
- the solvent pump 36 is driven with the valve V 1 being opened, with the three-way valve V 6 being opened to the flow pipe 37 and with the valve V 19 being closed.
- the solvent in the tank 31 flows into the flow pipe 38 through the first filter 32 and the second filter 33 and, after the temperature of the solvent is regulated by the solvent heat exchanger 39 , the solvent flows to the three-way valve V 9 through the flow pipe 46 .
- the solvent With the three-way valve V 9 being opened to the liquid supply pipe 51 , the solvent is supplied into the outer tub 4 through the liquid supply pipe 51 .
- the valve V 4 is closed.
- the amount of the solvent contained in the outer tub 4 is detected by the standard liquid surface switch 57 and, when a predetermined amount of the solvent (suitable for the washing) is contained in the outer tub 4 , the valve V 9 is switched so as to close the liquid supply pipe 51 and open the feedback pipe 52 .
- a soap is preliminarily mixed with the solvent contained in the tank 31 and, when the solvent passes through the flow pipe 46 , the concentration of the soap in the solvent is measured by the soap concentration sensor 50 . If the soap concentration is lower, the soap is pumped up from the soap container 60 through the soap pipe 61 with the valve V 17 being opened, and mixed with the supplied solvent.
- the three-way valve V 6 may be switched, as required, to cause the solvent to bypass the filters 32 , 33 , so that the solvent is applied to the solvent heat exchanger 39 through the bypass pipe 40 and then supplied to the outer tub 4 .
- the solvent pump 36 is driven with the valve V 4 being opened and with the valve V 1 being closed.
- the solvent is returned into the tank 31 with the three-way valve V 6 being opened to the flow pipe 37 and with the valve V 19 being opened.
- the solvent flowing through the flow pipe 37 may be caused to flow through the filters 32 and 33 , the flow pipe 38 , the solvent heat exchanger 39 and the flow pipe 46 with the valve V 19 being closed, and then flow through the three-way valve V 9 and the feedback pipe 52 back into the tank 31 .
- the solvent drained from the outer tub 4 after the washing process and the solvent removed from the laundry by the centrifugal force are passed through the filters 32 and 33 for decontamination, and then returned into the tank 31 .
- FIG. 3 is a block diagram illustrating the electrical construction of the dry cleaner 1 , particularly showing components related to the present invention.
- the dry cleaner 1 includes a control section 81 (controller) which includes, for example, a microcomputer and the like.
- the operation buttons 66 and the display panel 67 provided on the operation panel 2 b are connected to the control section 81 .
- an input signal corresponding to the button operation is inputted to the control section 81 .
- An output signal indicating the operation status of the dry cleaner 1 is inputted to the display panel 67 , whereby the operation status is displayed in the form of alphanumeric information on the display panel 67 .
- the three-way valve V 9 , the valve V 4 and the drum motor 21 (drive motor) to be controlled are connected to the control section 81 , and their operations are controlled by the control section 81 .
- the three-way valve V 9 is opened to the liquid supply pipe 51 to supply the solvent into the drum 5 (the outer tub 4 ).
- the valve V 4 is opened to return the solvent removed from the outer tub 4 into the tank 31 .
- the first valve V 27 and the second valve V 28 are connected to the control section 81 via the safety circuit 70 .
- the safety circuit 70 is electrically connected to the drum motor 21 , a speed detector 68 and a timer 69 .
- the rotation speed of the drum motor 21 is detected by the speed detector 68 .
- the timer 69 is actuated depending on the detection of the rotation speed, and a signal of the timer 69 is inputted to the safety circuit 70 .
- the control section 81 is permitted to control the operation of the first valve V 27 only after the safety circuit 70 is turned on in response to the signal inputted from the timer 69 .
- the control section 81 is permitted to control the operation of the second valve V 28 even if the safety circuit 70 is in an OFF state.
- a specific configuration of the safety circuit 70 will be described in detail with reference to FIG. 4 .
- FIG. 4 is a diagram illustrating a relay sequence controlling circuit 71 which constitutes a solvent gas concentration safety system.
- the solvent gas concentration safety system is herein defined as a system which prevents the ignition and explosion of the solvent gas in the drying process.
- the dry cleaner 1 includes the relay sequence controlling circuit 71 .
- the relay sequence controlling circuit 71 is a control circuit which controls the first valve V 27 and the second valve V 28 , and includes, for example, a parallel connection circuit which is connected to a DC power source (e.g., DC24V) and connects the first valve V 27 and the second valve V 28 as control objects in parallel. Further, the relay sequence controlling circuit 71 includes a first switch 77 and a second switch 78 which are connected in series with the first valve V 27 and the second valve V 28 , respectively, and controlled by the microcomputer in the control section 81 . When the first switch 77 and the second switch 78 are controlled to be turned on, ON signals are respectively inputted to the first valve V 27 and the second valve V 28 , whereby the valves V 27 and V 28 are opened.
- a DC power source e.g., DC24V
- a second contact 76 a of a second relay 76 is further connected in series with the serial connection of the first valve V 27 and the first switch 77 .
- the safety circuit 70 is configured such that the first valve V 27 is maintained in an inactive state irrespective of the ON control of the first switch 77 performed by the control section 81 unless the second contact 76 a is in an ON state.
- the relay sequence controlling circuit 71 further includes a detection circuit 79 for controlling the second contact 76 a.
- the detection circuit 79 is connected in parallel with the safety circuit 70 , and has a serial connection of the second relay 76 and a first contact 75 a of a first relay 75 , and a serial connection of the first relay 75 and a timer contact 69 a of the timer 69 which is connected in parallel with the aforesaid serial connection.
- the first relay 75 and the second relay 76 are devices such as electromagnetic relays each functioning to open and close a contact by an electromagnetic force. When electric current flows through an electromagnetic coil (not shown) provided in the relay 75 or 76 , the contact 75 a or 76 a is closed.
- a door switch 74 for detecting the state of the door (not shown) which opens and closes the outer tub opening 4 a is connected in series with the parallel connection of the first relay 75 and the second relay 76 .
- the door switch 74 is turned on when the door is closed.
- the timer 69 is connected in parallel with the door switch 74 and the first relay 75 (the door switch 74 and the second relay 76 ), and configured such that the timer contact 69 a of the timer 69 is turned on after a lapse of a predetermined period from the start of time measurement in response to the signal input.
- the timer 69 is connected in series with a detection switch 73 and, when the detection switch 73 is turned on, a time measurement starting signal is inputted to the timer 69 .
- the detection switch 73 is incorporated in an internal circuit (not shown) of the speed detector 68 connected to the drum motor 21 (see FIG. 3 ).
- the drum motor 21 has, for example, an inverter circuit incorporated therein to be frequency-controlled, and the speed detector 68 is connected to the inverter circuit.
- the speed detector 68 is configured so as to detect a frequency outputted when the drum motor 21 is rotated at a rotation speed not lower than a predetermined rotation speed level and to maintain the detection switch 73 in an ON state during the rotation of the drum motor 21 at the rotation speed not lower than the predetermined rotation speed level.
- the drum 5 When the liquid removing process is started after the completion of the washing process, the drum 5 is rotated at a high speed by a rotative driving force of the drum motor 21 to remove the solvent from the laundry.
- the rotation speed of the drum motor 21 is increased to 500 rpm or higher, for example, a frequency output corresponding to the rotation speed not lower than 500 rpm is detected by the speed detector 68 , and the detection switch 73 is turned on.
- an ON signal is inputted to the timer 69 from the detection switch 73 , and the timer 69 starts time measurement. If the ON state of the detection switch 73 , i.e., the rotation of the drum motor 21 at 500 rpm or higher, thereafter continues for 4 minutes, for example, the timer contact 69 a is turned on. In the washing process and the liquid removing process, the door (not shown) for opening and closing the outer tub opening 4 a is closed, so that the door switch 74 is maintained in an ON state.
- the speed detector 68 detects a drum motor rotation speed of 500 rpm or higher but the rotation of the drum 5 at this rotation speed does not continue for 4 minutes as measured by the timer 69 , the second contact 76 a is in an OFF state. Therefore, even if the control section 81 turns on the first switch 77 , the ON signal of the first switch 77 is not transmitted to the first valve V 27 , so that the first valve V 27 is maintained in the inactive state. That is, the control section 81 is permitted to turn on the first valve V 27 only after the drum 5 is rotated at a rotation speed of 500 rpm or higher for 4 minutes for the removal of the solvent from the laundry.
- the solvent gas concentration does not exceed the flammable lower limit concentration (e.g., 0.8 vol %). This is because the solvent has been removed by a certain amount from the laundry in the liquid removing process.
- the safety is ensured in the drying process, so that the dry cleaner 1 is highly safe without the danger of the ignition and the like. Further, the safety control is easily achieved simply by operating the detection switch 73 and the timer 69 .
- the second valve V 28 has a smaller steam supply capacity than the first valve V 27 . Even if the steam is continuously supplied to the drying heater 13 through the second valve V 28 , the temperature of the drying heater 13 is not significantly increased. This eliminates the need for controlling the second valve V 28 by the safety circuit 70 without the danger that the solvent gas concentration exceeds the flammable lower limit concentration. As a result, there is no need to incorporate an additional relay and the like in the circuit, thereby saving costs.
- the first valve V 27 is permitted to be opened on the condition that the drum is rotated at a rotation speed of 500 rpm or higher for 4 minutes for the removal of the solvent from the laundry.
- this condition is an exemplary condition.
- the condition for opening the first valve V 27 is not limited to the aforementioned one, but may be such that the liquid removing process is performed for a longer period as long as the resulting solvent gas concentration does not exceed the flammable lower limit concentration.
- the opening/closing control is performed on the first valve V 27 by way of example.
- the opening/closing control may be performed on the inlet valve V 20 provided in the steam passage 24 serving as a steam supply source for supplying the steam to the first valve V 27 .
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- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Control Of Washing Machine And Dryer (AREA)
- Accessory Of Washing/Drying Machine, Commercial Washing/Drying Machine, Other Washing/Drying Machine (AREA)
- Drying Of Solid Materials (AREA)
- Main Body Construction Of Washing Machines And Laundry Dryers (AREA)
- Electric Vacuum Cleaner (AREA)
Abstract
Description
- 1. Field of the Invention
- The present invention relates to a dry cleaner and, more specifically, to a dry cleaner which performs a washing process employing a flammable solvent, a liquid removing process and a drying process.
- 2. Description of Related Art
- Dry cleaners are conventionally known, which are adapted to wash laundry with a flammable solvent such as a petroleum-based solvent, remove the solvent from the washed laundry, and dry the laundry by applying hot air heated by a heater to the laundry for vaporization of the solvent.
- Meanwhile, the petroleum-based solvent is highly flammable. Therefore, if solvent gas resulting from the vaporization of the solvent from the laundry is present at a higher concentration during the drying of the laundry, the solvent gas is liable to be ignited by the heat of the heater, resulting in momentary flash or explosion.
- A known dry cleaner designed to prevent such accidents includes: a drum in which laundry is contained, and a washing process, a liquid removing process and a drying process are performed; an air circulation duct through which air is circulated to the drum; a drying heater of a steam heating type for heating the air flowing through the air circulation duct; a steam valve which is opened and closed for supplying steam to the drying heater; a drum inlet temperature sensor provided in the air circulation duct for measuring the temperature of gas to be supplied to the drum; a drum outlet temperature sensor which measures the temperature of gas having passed through the drum; and a control section including a microcomputer and the like for controlling the steam valve and the temperature sensors (see, for example, Japanese Unexamined Patent Publication No. 2005-218881).
- In the drying process, a drum outlet temperature is changed according to the amount of solvent contained in the laundry. That is, if the laundry contains a greater amount of solvent, the amount of solvent vaporized from the laundry is relatively great, so that the drum outlet temperature is relatively low. If a drum inlet temperature is elevated, for example, by promoting the heating with the steam valve being opened when the drum outlet temperature is lower, the solvent vaporization amount is further increased. If an atmosphere containing the solvent gas at a concentration higher than a safety value (e.g., 6.0 vol % where the solvent is gasoline No. 5) occurs in the drum, there is the danger of ignition.
- In the dry cleaner disclosed in Japanese Unexamined Patent Publication No. 2005-218881, the microcomputer monitors the drum outlet temperature and controls the opening and closing of the steam valve to control the temperature of the circulation air supplied from a drum inlet, thereby preventing an excessive increase in the amount of the solvent vaporized from the laundry and hence preventing the solvent gas concentration from exceeding the safety value for elimination of the danger.
- However, if the microcomputer malfunctions due to a failure of the control section or the like, i.e., a so-called microcomputer runaway occurs, in the dry cleaner disclosed in Japanese Unexamined Patent Publication No. 2005-218881, it will be impossible to control the steam valve and hence to control the solvent gas concentration. In this case, the solvent gas concentration in the drum is increased, so that the drying heater is liable to act as an ignition source to cause the ignition of the solvent gas.
- In view of the foregoing, it is a main object of the present invention to provide a highly safe dry cleaner which is free from the danger of the ignition and the like even if the microcomputer runaway occurs.
- It is another object of the present invention to provide a dry cleaner which ensures safety in the drying process.
- It is still another object of the present invention is to provide a safety circuit for a dry cleaner.
- According to the present invention, there is provided a dry cleaner which performs a laundry washing process employing a flammable solvent, a liquid removing process and a drying process, and includes: a treatment tub in which laundry is contained, and the washing process, the liquid removing process and the drying process are performed; an air circulation duct through which air taken out of the treatment tub flows back to the treatment tub in a closed flow circuit in the drying process; heating unit which heats the air flowing through the air circulation duct; controller which controls operation of the heating unit to perform the drying process; signal outputting unit which outputs a termination signal in response to completion of a predetermined liquid removing operation performed in the treatment tub; and a safety circuit which maintains the heating unit in an inactive state irrespective of a control status of the controller unless the termination signal is outputted.
- The treatment tub may include a liquid-tight outer tub, an inner tub rotatably provided in the outer tub and configured to be rotated to remove the solvent from the laundry contained therein by a centrifugal force, and a drive motor which rotates the inner tub. The signal outputting unit may include a mechanism which outputs the termination signal after the inner tub or the drive motor is rotated at a rotation speed not lower than a predetermined rotation speed level for a predetermined rotation period.
- The signal outputting unit may include a switch which is turned on when the rotation speed of the inner tub or the drive motor is not less than the predetermined rotation speed level, and a timer which starts time measurement in response to the turn-on of the switch to measure a switch turn-on time during which the switch is turned on and, when the switch turn-on time reaches a predetermined period, outputs the termination signal.
- The heating unit may include a heat exchanger which exchanges heat with the air flowing through the air circulation duct, and steam supplying unit which supplies steam to the heat exchanger. The safety circuit may be configured to prevent the steam from being supplied from the steam supplying unit to the heat exchanger to maintain the heating unit in the inactive state.
- The steam supplying unit may include a steam supplying passage through which the steam is supplied, and a valve which opens and closes the steam supplying passage. The safety circuit may be configured to constantly close the valve to maintain the heating unit in the inactive state.
- The steam supplying passage may include a plurality of steam supplying passages, and valves may be respectively disposed in the steam supplying passages. The safety circuit may be configured to constantly close a predetermined one of the valves to maintain the heating unit in the inactive state.
- According to the present invention, the heating unit is maintained in the inactive state by the safety circuit irrespective of the control status of the controller unless the termination signal is outputted by the signal outputting unit in response to the completion of the predetermined liquid removing operation performed in the treatment tub. Further, the signal outputting unit is configured as a hardware component separate from the controller (a microcomputer and the like) and, therefore, provides the termination signal independently of the controller. Thus, actuation of the heating unit is permitted only after the completion of the predetermined liquid removing operation.
- In general, the solvent gas concentration during the drying process is heavily dependent upon the amount of the solvent contained in the laundry and the temperature of the air applied to the laundry. Therefore, the solvent gas concentration is liable to be increased, as the contained solvent amount and the air temperature are increased. By reducing the amount of the solvent contained in the laundry to a predetermined level or less in the liquid removing process, the amount of the solvent to be vaporized in the drying process is reduced and, even if the air temperature is high, there is no possibility that the solvent gas concentration is increased to a predetermined concentration level or higher.
- Assuming, for example, that a flammable lower limit concentration (the lower limit concentration of the solvent gas at which the ignition of the solvent gas possibly occurs) is 0.8 vol %, an amount “A” of the solvent contained in the laundry is herein defined such that, even if laundry containing the solvent in an amount not greater than the solvent amount “A” is overheated, the solvent gas concentration is maintained at a level not greater than 0.8 vol % (in the following description, “A” is the solvent amount thus defined, unless otherwise specified). In this case, where the predetermined liquid removing operation according to the present invention is defined as a liquid removing operation to be performed so as to reduce the amount of the solvent contained in the laundry to a level not greater than “A”, the actuation of the heating unit is permitted only after the amount of the solvent contained in the laundry is reduced to the level not greater than “A”.
- As a result, even if the controller runs away when the heating unit is in an active state, e.g., if the heating unit is brought into an uncontrollable state to overheat the air in the air circulation duct, there is no possibility that the solvent gas concentration exceeds the flammable lower limit concentration, because the amount of the solvent contained in the laundry is not greater than “A”. This ensures the safety in the drying process. Thus, the dry cleaner is highly safe without the danger of the ignition and the like.
- According to the present invention, the signal outputting unit includes the mechanism which outputs the termination signal after the inner tub or the driving motor is rotated at a rotation speed not lower than the predetermined rotation speed level for the predetermined rotation period. Where the predetermined rotation speed level and the predetermined rotation period are respectively defined as a rotation speed and a rotation period which ensure that the amount of the solvent contained in the laundry after the liquid removing process can be reduced to a level not greater than “A”, the solvent gas concentration is prevented from being increased to the predetermined concentration level or higher by a simple method, i.e., by detecting the rotation speed of the inner tub and the rotation period.
- According to the present invention, the signal outputting unit includes the switch which is turned on when the rotation speed of the inner tub or the drive motor is not lower than the predetermined rotation speed level, and the timer which starts the time measurement in response to the turn-on of the switch to measure the switch turn-on time and, when the switch turn-on time reaches the predetermined period, outputs the termination signal. Therefore, the solvent gas concentration is prevented from being increased to the predetermined concentration level or higher by a simple method, i.e., by controlling the switch and the timer.
- According to the present invention, the heating unit includes the heat exchanger which exchanges heat with the air flowing through the air circulation duct, and the steam supplying unit which supplies steam to the heat exchanger. Further, the supply of the steam from the steam supplying unit to the heat exchanger is prevented by the safety circuit to maintain the heating unit in the inactive state. Thus, the steam is supplied to the heat exchanger to heat the air flowing through the air circulation duct only after the completion of the predetermined liquid removing operation. As a result, even if the controller runs away during the supply of the steam, e.g., if a great amount of steam is supplied from the steam supplying unit to steeply increase the temperature of the heat exchanger, the solvent gas concentration is prevented from being increased to the predetermined concentration level or higher, because the amount of the solvent contained in the laundry is not greater than “A”.
- According to the present invention, the steam supplying unit includes the steam supplying passage through which the steam is supplied, and the valve which opens and closes the steam supplying passage. Further, the valve is constantly closed by the safety circuit. With this arrangement, the solvent gas concentration is prevented from being increased to the predetermined concentration level or higher by a simple control operation, i.e., by constantly closing the valve.
- According to the present invention, the steam supplying passage includes the plurality of steam supplying passages, and the valves are respectively disposed in the steam supplying passages. Further, the predetermined one of the valves is constantly closed by the safety circuit. For example, the predetermined one of the valves may be defined as a valve which possibly increases the solvent gas concentration to a level higher than the flammable lower limit concentration when being opened. In this case, the solvent gas concentration is prevented from being increased to the predetermined concentration level or higher by constantly closing the thus defined valve. Further, there is no need to maintain the other valves in an inactive state by the safety circuit. This obviates the need for providing an additional device, thereby saving costs.
- The foregoing and other objects, features and effects of the present invention will become more apparent from the following detailed description of preferred embodiments with reference to the attached drawings.
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FIG. 1 is a front perspective view of major portions of a dry cleaner according to one embodiment of the present invention. -
FIG. 2 is a pipeline diagram of the dry cleaner shown inFIG. 1 . -
FIG. 3 is a block diagram illustrating the electrical construction of the dry cleaner shown inFIG. 1 , particularly showing components related to the present invention. -
FIG. 4 is a diagram illustrating a relay sequence controlling circuit which constitutes a solvent gas concentration safety system. -
FIG. 1 is a front perspective view of major portions of adry cleaner 1 according to one embodiment of the present invention. Reference will be made to directional arrows shown inFIG. 1 for directional notation. - Referring to
FIG. 1 , thedry cleaner 1 is, for example, for business use, and includes a generally rectangular box-shapedmain body 2, and a tank/filter kit 3 (seeFIG. 2 ). - The
main body 2 includes a rack-like frame 2 a. Anouter tub 4 and a drum 5 (inner tub) accommodated in theouter tub 4 are provided within theframe 2 a. Theframe 2 a is fixed to a floor. Anoperation panel 2 b is attached to a front face portion of theframe 2 a above theouter tub 4, specifically, at around a level of user's eyes. A user operates operation buttons 66 (to be described later) of theoperation panel 2 b to cause thedry cleaner 1 to perform desired operations by, and the operation status of thedry cleaner 1 is displayed on a display panel 67 (to be described later) of theoperation panel 2 b. - The
outer tub 4 is of a generally rectangular box shape, and has a generally cylindrical space defined therein. Theouter tub 4 has an outer tub opening 4 a formed in a front wall thereof as communicating with the inside thereof and having a round shape as seen from the front side. Anannular metal rim 4 b is fitted along the periphery of the outer tub opening 4 a. Anannular packing 4 c is attached to an inner peripheral front edge of therim 4 b. Therim 4 b has ahinge 4 d provided at a left edge portion thereof, and anengagement projection 4 e provided at a right edge portion thereof. A door (not shown) is attached to thehinge 4 d so as to be pivotal about a pivot shaft of thehinge 4 d to open and close the outer tub opening 4 a. The door (not shown) has an engagement projection (not shown) provided at a portion thereof opposite from the hinge side. When the door (not shown) closes the outer tub opening 4 a, the engagement projection (not shown) of the door is engaged with theengagement projection 4 e of therim 4 b, whereby the door (not shown) is locked with the outer tub opening 4 a closed. - Four corners of a bottom face of the
outer tub 4 are connected to theframe 2 a viadampers 2 c. Therefore, even if theouter tub 4 vibrates during the operation of thedry cleaner 1, the vibrations of theouter tub 4 are damped by thedampers 2 c and hence prevented from being propagated around thedry cleaner 1 through theframe 2 a. - The
drum 5 has a generally cylindrical hollow shape, and is disposed with its center shaft extending generally horizontally, specifically, extending anteroposteriorly. A drum motor 21 (seeFIG. 3 ) connected to the center shaft of thedrum 5 is disposed behind thedrum 5. A driving force generated by rotation of thedrum motor 21 is transmitted to thedrum 5 through the center shaft to rotate thedrum 5. Thedrum 5 has adrum opening 5 a formed in a front wall thereof at a position corresponding to the outer tub opening 4 a as communicating with the inside of thedrum 5. Thedrum opening 5 a is anteroposteriorly opposed to the outer tub opening 4 a. Therefore, laundry can be loaded into thedrum 5 through the outer tub opening 4 a and the drum opening 5 a with the door (not shown) being opened. A plurality ofbaffles 5 b are provided on an inner peripheral surface of thedrum 5 as projecting toward the center shaft. -
FIG. 2 is a pipeline diagram of thedry cleaner 1. With reference toFIG. 2 , the internal construction of thedry cleaner 1 will hereinafter be described in detail. - The
outer tub 4 has an air inlet 6 through which air is introduced into thedrum 5, and anair outlet 7 through which the air is expelled from thedrum 5. Theair outlet 7 and the air inlet 6 are connected to each other through a circulation duct 8 (air circulation duct). That is, thecirculation duct 8 is regarded as a closed circuit (closed flow circuit) which has the air inlet 6 and theair outlet 7 and connects theair outlet 7 and the air inlet 6 to each other. - The
dry cleaner 1 is an apparatus designed to perform a dry cleaning process with the use of a special flammable solvent (e.g., a petroleum-based solvent or the like). The dry cleaning process is advantageous in that laundry is less liable to shrink and oil stains are more easily removed as compared with a water cleaning process in which the laundry is washed with water. On the other hand, it is not desirable to release the solvent used for the dry cleaning to the external environment. Therefore, the dry cleaner according to this embodiment is of a type which is adapted to recover all the used solvent. - More specifically, a predetermined amount of solvent supplied from a
tank 31 to be described later is contained in theouter tub 4, and the laundry is washed with the solvent in a washing process. After the washing process, the solvent is recovered from theouter tub 4 into thetank 31. Further, thedrum 5 is rotated at a higher speed to remove residual solvent from the laundry. The removed solvent is also recovered into thetank 31. Thereafter, a drying process is performed to dry the laundry by circulating the air between thecirculation duct 8 and thedrum 5 while rotating thedrum 5 at a lower speed. The vapor of the solvent resulting from vaporization of the solvent from the laundry in the drying process is also recovered by condensation thereof. During the rotation of thedrum 5, the laundry is agitated by thebaffles 5 b. Thus, the laundry is efficiently washed and dried. - In the drying process, a
blower 10 is rotated by a blower motor 9, whereby the air in thedrum 5 is circulated from theair outlet 7 into the air inlet 6 through thecirculation duct 8. Dryingcoolers 11 and 12 are provided in thecirculation duct 8, and a drying heater 13 (heat exchanger) is provided adjacent the air inlet 6. The air flowing out of thedrum 5 into thecirculation duct 8 through theair outlet 7 contains the vaporized solvent (solvent gas). The air containing the solvent gas is cooled by the dryingcoolers 11 and 12, so that the solvent gas in the air is liquefied. That is, the solvent-containing air flowing through thecirculation duct 8 is cooled by the dryingcoolers 11 and 12, whereby the solvent is condensed and recovered from the air. Thereafter, the air is heated by the dryingheater 13, and the heated air is supplied as drying air into thedrum 5 through the air inlet 6. In thedrum 5, the heated air is heat-exchanged with the laundry, whereby the solvent contained in the laundry is vaporized. The vaporized solvent flows together with the air into thecirculation duct 8 through theair outlet 7. This cycle in which the air is circulated between thedrum 5 and thecirculation duct 8 is repeated, thereby drying the laundry in thedrum 5. Thedry cleaner 1 is configured such that the drying air from the air inlet 6 is supplied to the laundry in thedrum 5 through the outer tub opening 4 a and the drum opening 5 a. Thedrum opening 5 a is an opening having the greatest size in thedrum 5, so that the drying air can be efficiently supplied to the laundry through the drum opening 5 a. Further, the air in thedrum 5 is circulated through thecirculation duct 8. Therefore, the air heated by the dryingheater 13 and supplied into thedrum 5 is heat-exchanged with the laundry in thedrum 5 to vaporize moisture (solvent) from the laundry, and then reused for the drying of the laundry rather than being expelled together with the vaporized moisture to the outside. Accordingly, thedry cleaner 1 is environmentally friendly. - Meanwhile, the solvent is flammable. Therefore, there is the danger of ignition or explosion of the vaporized solvent unless the temperature of the heated air is reliably controlled in the drying process.
- For detecting the temperature of the heated air supplied into the
drum 5 from the air inlet 6, a druminlet temperature thermistor 14 and an inletover-temperature preventing thermistor 15 are provided downstream of the drying heater 13 (on a downstream side with respect to an air flow direction—this definition holds true for the following description) in thecirculation duct 8. Though not shown, the inlet over-temperature preventingthermistor 15 is connected to a transistor circuit, and configured such that the circuit is cut off through the transistor, for example, when a temperature of 95° C. is detected. Therefore, the inlet over-temperature preventingthermistor 15 is advantageous in that it ensures more accurate detection of an operation temperature and a quicker response to the temperature than a thermostat. - For detecting the temperature of the air expelled from the
air outlet 7, a drumoutlet temperature thermistor 16 and an abnormal outlettemperature judging thermistor 17 which monitors the drumoutlet temperature thermistor 16 to check whether or not the drumoutlet temperature thermistor 16 malfunctions are provided in thecirculation duct 8. For detecting the temperature of the air cooled by a downstream one of the two dryingcoolers 11 and 12, acooler temperature thermistor 18 and a coolerover-temperature preventing thermistor 19 which constitutes a part of a safety circuit are provided in thecirculation duct 8. - Further, an
aspiration port 20 and a gate valve V14 are provided between the drying cooler 12 and the dryingheater 13 in thecirculation duct 8 for regulating the internal pressure of thecirculation duct 8 when the circulation duct internal pressure is excessively increased. Normally, theaspiration port 20 is opened, and the gate valve V14 is opened to permit the air to flow through thecirculation duct 8. Further, thecirculation duct 8 has anexplosion protection port 26 which, if the solvent gas-containing air flowing through thecirculation duct 8 happens to be ignited to cause explosion, releases the blast of the explosion. Theexplosion protection port 26 is biased in a closing direction by a spring not shown. - The drying
coolers 11 and 12 are connected to a freezingmachine 23 throughcoolant passages machine 23 is disposed outside themain body 2. When a drying cooler electromagnetic valve 2Y inserted in thecoolant passage 22 a is opened, a coolant (e.g., cooling water) flows from the freezingmachine 23 into the drying cooler 12 and the drying cooler 11 through thecoolant passages coolers 11 and 12 are herein connected in series with each other to the freezingmachine 23, but may be connected in parallel with each other to the freezingmachine 23. More specifically, thecoolant passages coolers 11 and 12 to supply the coolant individually to the dryingcoolers 11 and 12 from the freezingmachine 23. Of course, freezingmachines 23 may be respectively provided for the dryingcoolers 11 and 12. - The drying
heater 13 is a so-called radiator which radiates heat of steam passing therethrough from fins thereof to heat the ambient atmosphere, and is connected to a steam passage 24 (steam supply passage) and asteam passage 25. More specifically, thesteam passage 24 connects an external steam source to the dryingheater 13. An inlet valve V20 is inserted in thesteam passage 24. Thesteam passage 24 is branched into a firststeam supply passage 24 a having a relatively great passage diameter and a secondsteam supply passage 24 b having a relatively small passage diameter between the dryingheater 13 and the inlet valve V20. A first valve V27 is inserted in the firststeam supply passage 24 a, and a second valve V28 is inserted in the secondsteam supply passage 24 b. In this embodiment, a path extending from thesteam passage 24 to the dryingheater 13 corresponds to the heating unit according to the present invention. On the other hand, thesteam passage 25 is a passage through which the steam supplied from thesteam passage 24 to the dryingheater 13 is expelled to the outside. - With the inlet valve V20 and the first valve V27 and/or the second valve V28 being opened, steam (e.g., steam at 110 to 120° C.) is supplied to the drying
heater 13, whereby the dryingheater 13 heats the air in thecirculation duct 8 by the steam. Since the firststeam supply passage 24 a and the secondsteam supply passage 24 b are different in steam supply capacity, the steam may be supplied to the dryingheater 13 from one or both of the firststeam supply passage 24 a and the secondsteam supply passage 24 b as required. - In the drying process, the rotation of the blower motor 9, and the opening and closing of the inlet valve V20 and the first valve V27 and/or the second valve V28 are typically controlled based on temperatures detected by the drum
inlet temperature thermistor 14, the drumoutlet temperature thermistor 16 and thecooler temperature thermistor 18. In thedry cleaner 1, a safety circuit 70 (to be described later) is constituted by an electric circuit which controls the opening and closing of the first valve V27 and the second valve V28 for prevention of the ignition and explosion of the solvent gas. The electric circuit for controlling the opening and closing of the valves V27, V28 will be described in detail later. - The tank/filter kit 3 includes the
tank 31 which stores the solvent, and afirst filter 32 and asecond filter 33 which are connected in series for filtering the solvent pumped up from thetank 31. A pump-uppipe 34 is connected to a bottom of thetank 31 at one end thereof. A valve V1 is inserted in the pump-uppipe 34. The other end of the pump-uppipe 34 is connected to ajunction 35. Asolvent pump 36 is connected to thejunction 35 on its suction side and to an inlet of a three-way valve V6 on its ejection side. One outlet of the three-way valve V6 is connected to one end of aflow pipe 37, and the other end of theflow pipe 37 is connected to thetank 31 via a valve V19. Theflow pipe 37 is branched at its intermediate portion (between the three-way valve V6 and the valve V19) to be connected to the serial connection of thefirst filter 32 and thesecond filter 33. Aflow pipe 38 is connected to an outlet of thesecond filter 33, and a distal end of theflow pipe 38 is connected to an inlet of asolvent heat exchanger 39 provided in themain body 2. - A
bypass pipe 40 is connected to the other outlet of the three-way valve V6 at one end thereof, and the other end of thebypass pipe 40 joins theflow pipe 38 connected to the inlet of thesolvent heat exchanger 39. - Therefore, the solvent is applied to the
solvent heat exchanger 39 through thefirst filter 32 and thesecond filter 33, or applied to thesolvent heat exchanger 39 through thebypass pipe 40 with thefilters - A
steam pipe 41 and acoolant pipe 42 are provided in thesolvent heat exchanger 39. Thesteam pipe 41 and thecoolant pipe 42 are each wound, for example, in a coil shape.Steam passages steam pipe 41. Thesteam passage 43 connects thesteam pipe 41 and thesteam passage 24, and a valve V21 is inserted in thesteam passage 43. On the other hand, thesteam passage 44 is a passage through which the steam supplied from thesteam passage 43 to thesteam pipe 41 is discharged to the outside. With the valve V21 being opened, the steam flows into thesteam pipe 41 through thesteam passage 43 to be discharged through thesteam passage 44. While the solvent passes through thesolvent heat exchanger 39, thesteam pipe 41 at a high temperature exchanges heat with the solvent to heat the solvent. On the other hand,coolant passages coolant pipe 42, and a solvent cooler electromagnetic valve 3Y is inserted in thecoolant passage 45 a. With the solvent cooler electromagnetic valve 3Y being opened, the coolant passes through thecoolant pipe 42. While the solvent passes through thesolvent heat exchanger 39, thecoolant pipe 42 exchanges heat with the solvent to cool the solvent. By controlling the opening and closing of the valve V21 and the opening and closing of the solvent cooler electromagnetic valve 3Y, thesolvent heat exchanger 39 is switched to heat or cool the solvent, whereby the temperature of the solvent passing through thesolvent heat exchanger 39 is regulated at a desired temperature level. - A
flow pipe 46 is connected to an outlet of thesolvent heat exchanger 39 at one end thereof. The other end of theflow pipe 46 is connected to an inlet of a three-way valve V9. Aliquid temperature thermistor 47 for measuring the temperature of the solvent and a liquidover-temperature preventing thermistor 48 for preventing a liquid temperature from being increased to a predetermined temperature level or higher are provided in theflow pipe 46. - A soap concentration sensor 50 is provided downstream of these two thermistors in the
flow pipe 46. - A
liquid supply pipe 51 is connected to one outlet of the three-way valve V9 at one end thereof and to theouter tub 4 at the other end thereof, so that the solvent can be supplied into thedrum 5. Afeedback pipe 52 is connected to the other outlet of the three-way valve V9 at one end thereof and to thetank 31 at the other end thereof. - A
recovery pipe 62 for recovering the solvent condensed by the dryingcoolers 11 and 12 in thecirculation duct 8 has one end connected to a potion of thecirculation duct 8 below the dryingcoolers 11 and 12. The other end of therecovery pipe 62 is connected to awater separator 63. In thewater separator 63, water contained in the recovered solvent is separated, and the separated water is drained through adrain pipe 64. Then, the recovered solvent is returned into thetank 31 through arecovery pipe 65. - The
outer tub 4 has adrain port 55 provided at its lowermost portion, and a liquidsurface detection chamber 56 is connected to thedrain port 55. The liquidsurface detection chamber 56 is provided with two liquid surface switches, i.e., a standardliquid surface switch 57 and a drainliquid surface switch 58. The liquidsurface detection chamber 56 also serves as a trap which traps a button or the like dislodged from the laundry and falling through thedrain port 55 during the washing process. - A
recovery pipe 59 is connected to a lower end of the liquidsurface detection chamber 56 at one end thereof. A valve V4 is inserted in therecovery pipe 59. The other end of therecovery pipe 59 is connected to thejunction 35. - A
soap pipe 61 is connected to asoap container 60 at one end thereof and to thejunction 35 at the other end thereof. A valve V17 is inserted in thesoap pipe 61. - Next, the flow of the solvent will be described with reference to the pipeline diagram of
FIG. 2 . - In the washing process, the solvent stored in the
tank 31 is supplied into the drum 5 (the outer tub 4). At this time, thesolvent pump 36 is driven with the valve V1 being opened, with the three-way valve V6 being opened to theflow pipe 37 and with the valve V19 being closed. Thus, the solvent in thetank 31 flows into theflow pipe 38 through thefirst filter 32 and thesecond filter 33 and, after the temperature of the solvent is regulated by thesolvent heat exchanger 39, the solvent flows to the three-way valve V9 through theflow pipe 46. With the three-way valve V9 being opened to theliquid supply pipe 51, the solvent is supplied into theouter tub 4 through theliquid supply pipe 51. During the supply of the solvent, the valve V4 is closed. The amount of the solvent contained in theouter tub 4 is detected by the standardliquid surface switch 57 and, when a predetermined amount of the solvent (suitable for the washing) is contained in theouter tub 4, the valve V9 is switched so as to close theliquid supply pipe 51 and open thefeedback pipe 52. - A soap is preliminarily mixed with the solvent contained in the
tank 31 and, when the solvent passes through theflow pipe 46, the concentration of the soap in the solvent is measured by the soap concentration sensor 50. If the soap concentration is lower, the soap is pumped up from thesoap container 60 through thesoap pipe 61 with the valve V17 being opened, and mixed with the supplied solvent. - During the supply of the solvent to the
outer tub 4, the three-way valve V6 may be switched, as required, to cause the solvent to bypass thefilters solvent heat exchanger 39 through thebypass pipe 40 and then supplied to theouter tub 4. - In a solvent draining and removing process, the
solvent pump 36 is driven with the valve V4 being opened and with the valve V1 being closed. The solvent is returned into thetank 31 with the three-way valve V6 being opened to theflow pipe 37 and with the valve V19 being opened. - Alternatively, the solvent flowing through the
flow pipe 37 may be caused to flow through thefilters flow pipe 38, thesolvent heat exchanger 39 and theflow pipe 46 with the valve V19 being closed, and then flow through the three-way valve V9 and thefeedback pipe 52 back into thetank 31. Thus, the solvent drained from theouter tub 4 after the washing process and the solvent removed from the laundry by the centrifugal force are passed through thefilters tank 31. -
FIG. 3 is a block diagram illustrating the electrical construction of thedry cleaner 1, particularly showing components related to the present invention. - The
dry cleaner 1 includes a control section 81 (controller) which includes, for example, a microcomputer and the like. - The
operation buttons 66 and thedisplay panel 67 provided on theoperation panel 2 b are connected to thecontrol section 81. When the user operates theoperation buttons 66, an input signal corresponding to the button operation is inputted to thecontrol section 81. An output signal indicating the operation status of thedry cleaner 1 is inputted to thedisplay panel 67, whereby the operation status is displayed in the form of alphanumeric information on thedisplay panel 67. - The three-way valve V9, the valve V4 and the drum motor 21 (drive motor) to be controlled are connected to the
control section 81, and their operations are controlled by thecontrol section 81. In the washing process, for example, the three-way valve V9 is opened to theliquid supply pipe 51 to supply the solvent into the drum 5 (the outer tub 4). In the liquid removing process, the valve V4 is opened to return the solvent removed from theouter tub 4 into thetank 31. - The first valve V27 and the second valve V28 are connected to the
control section 81 via thesafety circuit 70. - The
safety circuit 70 is electrically connected to thedrum motor 21, aspeed detector 68 and atimer 69. The rotation speed of thedrum motor 21 is detected by thespeed detector 68. Thetimer 69 is actuated depending on the detection of the rotation speed, and a signal of thetimer 69 is inputted to thesafety circuit 70. Thecontrol section 81 is permitted to control the operation of the first valve V27 only after thesafety circuit 70 is turned on in response to the signal inputted from thetimer 69. On the other hand, thecontrol section 81 is permitted to control the operation of the second valve V28 even if thesafety circuit 70 is in an OFF state. A specific configuration of thesafety circuit 70 will be described in detail with reference toFIG. 4 . -
FIG. 4 is a diagram illustrating a relaysequence controlling circuit 71 which constitutes a solvent gas concentration safety system. The solvent gas concentration safety system is herein defined as a system which prevents the ignition and explosion of the solvent gas in the drying process. For this system, thedry cleaner 1 includes the relaysequence controlling circuit 71. - The relay
sequence controlling circuit 71 is a control circuit which controls the first valve V27 and the second valve V28, and includes, for example, a parallel connection circuit which is connected to a DC power source (e.g., DC24V) and connects the first valve V27 and the second valve V28 as control objects in parallel. Further, the relaysequence controlling circuit 71 includes afirst switch 77 and asecond switch 78 which are connected in series with the first valve V27 and the second valve V28, respectively, and controlled by the microcomputer in thecontrol section 81. When thefirst switch 77 and thesecond switch 78 are controlled to be turned on, ON signals are respectively inputted to the first valve V27 and the second valve V28, whereby the valves V27 and V28 are opened. - A
second contact 76 a of asecond relay 76 is further connected in series with the serial connection of the first valve V27 and thefirst switch 77. Thus, thesafety circuit 70 is configured such that the first valve V27 is maintained in an inactive state irrespective of the ON control of thefirst switch 77 performed by thecontrol section 81 unless thesecond contact 76 a is in an ON state. - The relay
sequence controlling circuit 71 further includes adetection circuit 79 for controlling thesecond contact 76 a. - The
detection circuit 79 is connected in parallel with thesafety circuit 70, and has a serial connection of thesecond relay 76 and afirst contact 75 a of afirst relay 75, and a serial connection of thefirst relay 75 and atimer contact 69 a of thetimer 69 which is connected in parallel with the aforesaid serial connection. - The
first relay 75 and thesecond relay 76 are devices such as electromagnetic relays each functioning to open and close a contact by an electromagnetic force. When electric current flows through an electromagnetic coil (not shown) provided in therelay contact - A
door switch 74 for detecting the state of the door (not shown) which opens and closes the outer tub opening 4 a is connected in series with the parallel connection of thefirst relay 75 and thesecond relay 76. Thedoor switch 74 is turned on when the door is closed. - The
timer 69 is connected in parallel with thedoor switch 74 and the first relay 75 (thedoor switch 74 and the second relay 76), and configured such that thetimer contact 69 a of thetimer 69 is turned on after a lapse of a predetermined period from the start of time measurement in response to the signal input. Thetimer 69 is connected in series with adetection switch 73 and, when thedetection switch 73 is turned on, a time measurement starting signal is inputted to thetimer 69. - The
detection switch 73 is incorporated in an internal circuit (not shown) of thespeed detector 68 connected to the drum motor 21 (seeFIG. 3 ). Thedrum motor 21 has, for example, an inverter circuit incorporated therein to be frequency-controlled, and thespeed detector 68 is connected to the inverter circuit. Thespeed detector 68 is configured so as to detect a frequency outputted when thedrum motor 21 is rotated at a rotation speed not lower than a predetermined rotation speed level and to maintain thedetection switch 73 in an ON state during the rotation of thedrum motor 21 at the rotation speed not lower than the predetermined rotation speed level. - Next, the control sequence of the relay
sequence controlling circuit 70 will be described. - When the liquid removing process is started after the completion of the washing process, the
drum 5 is rotated at a high speed by a rotative driving force of thedrum motor 21 to remove the solvent from the laundry. When the rotation speed of thedrum motor 21 is increased to 500 rpm or higher, for example, a frequency output corresponding to the rotation speed not lower than 500 rpm is detected by thespeed detector 68, and thedetection switch 73 is turned on. - Upon the turn-on of the
detection switch 73, an ON signal is inputted to thetimer 69 from thedetection switch 73, and thetimer 69 starts time measurement. If the ON state of thedetection switch 73, i.e., the rotation of thedrum motor 21 at 500 rpm or higher, thereafter continues for 4 minutes, for example, thetimer contact 69 a is turned on. In the washing process and the liquid removing process, the door (not shown) for opening and closing the outer tub opening 4 a is closed, so that thedoor switch 74 is maintained in an ON state. - With the
timer contact 69 a being in an ON state, electric current flows through the electromagnetic coil provided in thefirst relay 75 to turn on thefirst contact 75 a. With thefirst contact 75 a being in an ON state, electric current flows through the electromagnetic coil provided in thesecond relay 76 to turn on thesecond contact 76 a. Thus, thecontrol section 81 is permitted to control the turn-on of thefirst switch 77, whereby electrical conduction between the positive side and the negative side of the first valve V27 is established to open the first valve V27. - If the
speed detector 68 detects a drum motor rotation speed of 500 rpm or higher but the rotation of thedrum 5 at this rotation speed does not continue for 4 minutes as measured by thetimer 69, thesecond contact 76 a is in an OFF state. Therefore, even if thecontrol section 81 turns on thefirst switch 77, the ON signal of thefirst switch 77 is not transmitted to the first valve V27, so that the first valve V27 is maintained in the inactive state. That is, thecontrol section 81 is permitted to turn on the first valve V27 only after thedrum 5 is rotated at a rotation speed of 500 rpm or higher for 4 minutes for the removal of the solvent from the laundry. - As a result, even if the steam is continuously supplied to the drying
heater 13, for example, due to runaway of the microcomputer of thecontrol section 81 to apply high temperature air to the laundry in the drying process, the solvent gas concentration does not exceed the flammable lower limit concentration (e.g., 0.8 vol %). This is because the solvent has been removed by a certain amount from the laundry in the liquid removing process. Thus, the safety is ensured in the drying process, so that thedry cleaner 1 is highly safe without the danger of the ignition and the like. Further, the safety control is easily achieved simply by operating thedetection switch 73 and thetimer 69. - Further, the second valve V28 has a smaller steam supply capacity than the first valve V27. Even if the steam is continuously supplied to the drying
heater 13 through the second valve V28, the temperature of the dryingheater 13 is not significantly increased. This eliminates the need for controlling the second valve V28 by thesafety circuit 70 without the danger that the solvent gas concentration exceeds the flammable lower limit concentration. As a result, there is no need to incorporate an additional relay and the like in the circuit, thereby saving costs. - It should be understood that the present invention be not limited to the embodiment described above, but various modifications may be made within the purview of the claims.
- In the embodiment described above, for example, the first valve V27 is permitted to be opened on the condition that the drum is rotated at a rotation speed of 500 rpm or higher for 4 minutes for the removal of the solvent from the laundry. However, this condition is an exemplary condition. The condition for opening the first valve V27 is not limited to the aforementioned one, but may be such that the liquid removing process is performed for a longer period as long as the resulting solvent gas concentration does not exceed the flammable lower limit concentration.
- In the embodiment described above, the opening/closing control is performed on the first valve V27 by way of example. Alternatively, the opening/closing control may be performed on the inlet valve V20 provided in the
steam passage 24 serving as a steam supply source for supplying the steam to the first valve V27. - While the embodiment of the present invention has been described in detail, it should be understood that the embodiment is merely illustrative of the technical principles of the present invention but not limitative of the invention. The spirit and scope of the present invention are to be limited only by the appended claims.
- This application corresponds to Japanese Patent Application No. 2006-313317 filed in the Japanese Patent Office on Nov. 20, 2006, the disclosure of which is incorporated herein by reference.
Claims (10)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2006313317A JP4901434B2 (en) | 2006-11-20 | 2006-11-20 | Dry cleaner |
JP2006-313317 | 2006-11-20 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20080115540A1 true US20080115540A1 (en) | 2008-05-22 |
Family
ID=39176491
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/984,148 Abandoned US20080115540A1 (en) | 2006-11-20 | 2007-11-14 | Dry cleaner |
Country Status (4)
Country | Link |
---|---|
US (1) | US20080115540A1 (en) |
EP (1) | EP1923500A3 (en) |
JP (1) | JP4901434B2 (en) |
CN (1) | CN100594268C (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090277035A1 (en) * | 2006-02-20 | 2009-11-12 | Lg Electronics Inc. | Drying machine and method for controlling the same |
US7941937B2 (en) * | 2002-11-26 | 2011-05-17 | Lg Electronics Inc. | Laundry dryer control method |
US7997006B2 (en) * | 2007-01-12 | 2011-08-16 | Lg Electronics Inc. | Laundry machine and control method thereof |
US8424220B2 (en) | 2006-06-12 | 2013-04-23 | Lg Electronics Inc. | Laundry dryer and method for controlling the same |
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US2142042A (en) * | 1935-10-12 | 1938-12-27 | Us Hoffman Machinery Corp | Process for drying |
US2203422A (en) * | 1937-07-24 | 1940-06-04 | Us Hoffman Machinery Corp | Apparatus for drying |
US3106831A (en) * | 1961-10-03 | 1963-10-15 | Borg Warner | Dry cleaning machine |
US3206950A (en) * | 1963-02-25 | 1965-09-21 | Space Corp | Dry cleaning system |
US3254513A (en) * | 1963-11-01 | 1966-06-07 | Philco Corp | Control system for automatic drycleaning machines |
US3805561A (en) * | 1972-06-29 | 1974-04-23 | Cissell W Mfg Co | Garment finishing apparatus |
US5367787A (en) * | 1992-08-05 | 1994-11-29 | Sanyo Electric Co., Ltd. | Drying machine |
US5887454A (en) * | 1997-01-31 | 1999-03-30 | Renzacci S.P.A. Industria Lavatrici | Dry-cleaning machine with steam heated drying air |
US5943721A (en) * | 1998-05-12 | 1999-08-31 | American Dryer Corporation | Liquified gas dry cleaning system |
US20040010937A1 (en) * | 2002-04-23 | 2004-01-22 | Sanyo Electric Co., Ltd. | Dry cleaning machine |
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JP2902902B2 (en) * | 1993-06-04 | 1999-06-07 | 三洋電機株式会社 | Dryer |
ITAN20020005A1 (en) * | 2002-01-25 | 2003-07-25 | Gian Vieri Nardini | CONTROL OF DRYING IN DRY CLEANING MACHINES BY MEASURING THE CONDENSATE |
JP4498293B2 (en) | 2005-03-09 | 2010-07-07 | 株式会社日本総合研究所 | Integrated display system, method and program |
JP2005218881A (en) | 2005-04-25 | 2005-08-18 | Sanyo Electric Co Ltd | Washing and drying machine |
-
2006
- 2006-11-20 JP JP2006313317A patent/JP4901434B2/en not_active Expired - Fee Related
-
2007
- 2007-09-21 CN CN200710152787A patent/CN100594268C/en not_active Expired - Fee Related
- 2007-11-14 US US11/984,148 patent/US20080115540A1/en not_active Abandoned
- 2007-11-15 EP EP07022222A patent/EP1923500A3/en not_active Withdrawn
Patent Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
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US2142042A (en) * | 1935-10-12 | 1938-12-27 | Us Hoffman Machinery Corp | Process for drying |
US2203422A (en) * | 1937-07-24 | 1940-06-04 | Us Hoffman Machinery Corp | Apparatus for drying |
US3106831A (en) * | 1961-10-03 | 1963-10-15 | Borg Warner | Dry cleaning machine |
US3206950A (en) * | 1963-02-25 | 1965-09-21 | Space Corp | Dry cleaning system |
US3254513A (en) * | 1963-11-01 | 1966-06-07 | Philco Corp | Control system for automatic drycleaning machines |
US3805561A (en) * | 1972-06-29 | 1974-04-23 | Cissell W Mfg Co | Garment finishing apparatus |
US5367787A (en) * | 1992-08-05 | 1994-11-29 | Sanyo Electric Co., Ltd. | Drying machine |
US5887454A (en) * | 1997-01-31 | 1999-03-30 | Renzacci S.P.A. Industria Lavatrici | Dry-cleaning machine with steam heated drying air |
US5943721A (en) * | 1998-05-12 | 1999-08-31 | American Dryer Corporation | Liquified gas dry cleaning system |
US20040010937A1 (en) * | 2002-04-23 | 2004-01-22 | Sanyo Electric Co., Ltd. | Dry cleaning machine |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
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US7941937B2 (en) * | 2002-11-26 | 2011-05-17 | Lg Electronics Inc. | Laundry dryer control method |
US20090277035A1 (en) * | 2006-02-20 | 2009-11-12 | Lg Electronics Inc. | Drying machine and method for controlling the same |
US8931186B2 (en) | 2006-02-20 | 2015-01-13 | Lg Electronics Inc. | Drying machine and method for controlling the same |
US9206542B2 (en) | 2006-02-20 | 2015-12-08 | Lg Electronics Inc. | Drying machine and method for controlling the same |
US8424220B2 (en) | 2006-06-12 | 2013-04-23 | Lg Electronics Inc. | Laundry dryer and method for controlling the same |
US7997006B2 (en) * | 2007-01-12 | 2011-08-16 | Lg Electronics Inc. | Laundry machine and control method thereof |
Also Published As
Publication number | Publication date |
---|---|
CN100594268C (en) | 2010-03-17 |
EP1923500A3 (en) | 2009-12-30 |
JP4901434B2 (en) | 2012-03-21 |
EP1923500A2 (en) | 2008-05-21 |
CN101187144A (en) | 2008-05-28 |
JP2008125745A (en) | 2008-06-05 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: SANYO ELECTRIC TECHNO CREATE CO., LTD., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:NISHINO, MASAFUMI;MURAKAMI, KAZUSHIGE;NAGANAWA, MITSURU;REEL/FRAME:020159/0494 Effective date: 20071030 Owner name: SANYO ELECTRIC CO., LTD., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:NISHINO, MASAFUMI;MURAKAMI, KAZUSHIGE;NAGANAWA, MITSURU;REEL/FRAME:020159/0494 Effective date: 20071030 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |