Patent GB-1025081-A (GB)
Title: Dry-cleaning system
IPC: D06F58/04
Filed: 1962-09-26
Abstract: 1,025,081. Dry-cleaning apparatus. BORGWARNER CORPORATION. Sept. 26, 1962 [Oct. 3, 1961], No. 36610/62. Heading D1A. A closed circuit solvent supply system for one or more dry-cleaning machines I, II is shown in Fig. 3. Each machine has its own storage container 152 arranged below it but shares in a common filter and circulating system for the solvent. Solvent is supplied to the bottom of each machine through a hose 171 and rises to a level of an opening in the tub and overflows through a hose 164 into a lint filter 159 of the storage tank 152. All the tanks 152 are connected in series and solvent is extracted from them by a pump 174 through a pipe 173 and delivered to the bottom of a filter 177. The outlet pipe 178 at the top of the filter passes through a water-cooled heat exchanger 210 and through a pipe 211 to a supply manifold 213 which at its far end has an inverted U-pipe connection 212 to the storage tank of the end machine so that a continuous circulation of the solvent through the filter is maintained. The solvent for each machine is drawn off from the manifold 213 through pipes 221 control valves 222 and hoses 171 under gravity of the head of the U-pipe 212, an air vent pipe 219 being provided from the tanks 152 to the pipe 212. A solvent level switch 267 is adapted to be actuated if the pressure head of the solvent fails to operate warning lamps on the machines. When the filter 177 becomes blocked as indicated by a pressure gauge the pump 174 is stopped and the filter isolated from the circulating system; air under pressure is admitted to the filter to break the filter cake and soil from the filter screens which drops to the bottom of the filter. Further filter material may then be added to the system and the filter operation resumed. When required the sludge from the filter may be backwashed into a sludge tank 204. The solvent is drained from the tub after a cleaning operation by operation of the control valve 222 so that the solvent flows via hose 171 and hose 252 into the filter to tank 152. During the drying operation the condensed solvent is directed through valve 222 to a water separator before it is returned to tank 152. Each machine comprises a rotatable perforated basket 18, Fig. 5 (not shown), within a fixed tub 11 which is adapted to be rotated at low or high speed for washing with a solvent such as perchlorethylene or spin drying respectively by an electric motor M, Fig. 6 (not shown) two-speed gear T and belt drives 42, 22. The basket 18 is also adapted to be rotated slowly for a tumble dry when a heater 73 within the tub 11 and an air circulating fan 32 driven by a belt 63 are also in operation. A condenser 77 provided with cooling water is also provided in the lower part of the tub to condense the solvent vaporized during this drying operation which then drains away. Air inlet and exhaust valves 83, 84 are provided in the tub 11 to flush away solvent vapour left at the end of the drying operation through a blower and ventilating ducts. The door 17 of the tub 11 has a lock mechanism which is electrically controlled so that the door cannot be opened during the operating cycle of the machine. The cleaning and drying cycle of operations of each machine is started by a coin-operated mechanism and controlled automatically thereafter by a timer motor operating cams through a step-by-step mechanism to actuate sequentially switches controlling the operation of the various valves and other components of the machine. Two sub-interval timers are also provided the first of which provides a drying time delay in the event of an interruption of air flow during the dry cycle due, for example, to the fan belt being broken or loose or excessive loading of the basket. The second sub-interval timer provides a delay of the main timer during a "Pre-dry" period and "Timed dry pause" period.