| 摘要 |
1486725 Dishwashing machines STIERLENMAQUET AG 28 Feb 1975 8585/75 Heading A4F [Also in Division F4] A dishwashing machine is provided with a heat recovery apparatus which comprises a heat pump assembly 1 disposed in a housing 17 on a housing 4 of the dishwashing machine and which condenses steam issuing from the machine to recover the heat of vaporization and yielding up the recovered heat to washing or rinsing water used in the machine. The machine shown has entry and exit rails 5, 6. Air-steam mixture, emitted from the inlet and outlet of the housing 4, is drawn by a fan 16 in the heat pump assembly through ducts 2, 3, inlet slots 21, 31 in the housing 17, and an evaporator 12 where the steam condenses, and the working substance of the heat pump, e.g. difluorodichloromethane, is evaporated. Air is discharged through an opening 19, whilst the evaporated working substance is compressed by a motor driven compressor 11 and fed through condensers 13, 14 where heat is abstracted therefrom by washing and rinsing water. The operation of the heat pump is regulated by a thermostatic device in accordance with the heat output of the dishwashing machine. The working substance enters the evaporator 12 via series connected electromagnetic shut-off and expansion valves 115, 114 in parallel with series connected electromagnetic shut-off and expansion valves 116, 113. During heating of the washing water, a thermostat (111), Fig. 7 (not shown), maintains the valve 116 open whilst the valve 115 is closed, and the flow to the evaporator 12 is via the expansion valve 113 which is thermostatically controlled in accordance with the temperature of the working substance leaving the evaporator 12. When the washing water is heated up, a thermostat (112) closes the valve 116, and the compressor 11 is de-energized by opening of a suction operated switch (111). The washing water temperature then rises so that the thermostat (112) reopens the valve 116 and switch (111) again closes. Such alternate switching off and on of the compressor 11 maintains the washing water temperature approximately constant until energization of a washing water pump. The valve 115 is then opened so that the flow to the evaporator 12 is controlled by the expansion valve 114, which has a much stronger throttling action than the valve 113 so that the washing water is cooled. The thermostat (112) is thereby actuated to close the valve 115 and open the valve 116 so that the heat pump continues to operate at full load, controlled by the expansion valve 113. |
