TUBULAR ELECTRIC HEATER

FIELD: electricity.SUBSTANCE: tubular electric heater contains a heat-producing element 1, for example in a form of a current-conducting spiral placed inside a protective metal shell 2 with an external circumferential finning 3, at the ends of the metal shell 2 there are sealed current leads 4 connected to the outputs of the current-conducting spiral, porous ceramic beads 5 of a tear-drop shape with the heat-producing element 1 placed in their internal opening, along their perimeter the beads are covered by the protective metal shell 2, the porous ceramic beads have width variable by height thus covering the heat-producing element completely or covering it minimally in the upper part, the inner cavity of the tubular electric heater, including pores of the ceramic beads, is filled with liquid partially. When voltage is supplied to the current leads 4 connected to the outputs of the current-conducting spiral the temperature of the spiral is increased as far as heat conductivity of the porous ceramic beads 5 is low, heating of the spiral of the heat-producing element 1 takes place fast, nevertheless the temperature of the protective shell 2 and finning 3 is defined by the temperature of the external heat carrier. As far as the inner cavity of the heater and pores of the beads are filled with liquid at certain temperature this liquid boils, steal comes through the pores to the space between the porous beads 5, where it is condensed at the inner surface of the protective shell 2 giving it the accumulated evaporation heat. The condensed steam in the form of liquid comes to the surface of the porous beads 5 and due to capillary action it is saturated inside into the beads 5 coming down to the heated spiral, there it boils again thus accumulating evaporation heat and closing the cycle of heat transfer and circulation loop.EFFECT: improving operating reliability.2 dwg Изобретение относится к электротехнике и позволяет повысить ресурс и эксплуатационную надежность трубчатого нагревателя. Трубчатый электронагреватель содержит тепловыделяющий элемент 1, например, в виде токопроводящей спирали, расположенный внутри защитной металлической оболочки 2, имеющей внешнее поперечное оребрение 3, на концах металлической оболочки 2 выполнены герметизированные токоподводы 4, присоединенные к выводам токопроводящей спирали, пористые керамические шайбы 5, имеющие каплевидную форму, во внутреннем отверстии которых размещен тепловыделяющий элемент 1, а по внешнему обводу шайбы заклю