PORTABLE HEATING APPARATUS FOR PROTECTED GROUND Russian patent published in 1997 - IPC

FIELD: agriculture and municipal engineering, in particular, air heating in greenhouses and film coverings, rural dwellings and animal houses. SUBSTANCE: apparatus has housing 1 made from electrically insulating and heat-insulating material. Housing 1 incorporates heating tubular member 2 filled with current-conductive liquid 3 (water), compensator 4 for accumulating excessive current-conductive liquid produced during heating, and heat-exchanger 5. Heat-exchanger 5 is made from detachable thin-walled metal pipes connected with housing 1 through upper branch pipes 6 and lower branch pipes 7 to define closed channel extending along periphery in vertical plane from housing 1. Length of heat-exchanger channel sides exceeds its height on housing 1 between branch pipes 6 and 7 by 3-10 times. Heat-exchanger 5 may have different configuration and number of closed channels, but triangular configuration is preferable, with sides of channels being inclined from housing for an angle of 75-90 deg. Electrode 8 is positioned above lower branch pipes within heating member 2 at distance making 0.1-0.5 of mentioned height. Apparatus heats ground and air by directing safety voltage electric current through current-conductive liquid. When power is cutoff, apparatus serves as pump for supplying excessive air heat produced due to intensive solar radiation to ground without overheating and injure to plants below film covering. Apparatus may also be used to recuperate heat from ground to air during night frosts, when unexpected power source cutoff occurs. EFFECT: increased efficiency in heating protected ground without damage to plants. 2 cl, 8 dwg