Patent ID: 8281939

Claim:
A heat generating device comprising: a plurality of racks, each of rack having a base and multiple arms extending radially from the base, each arm having two engaging members and each engaging member having a neck connected to the arm and an enlarged block connected to the neck, each block having multiple bosses extending from a surface facing the arm; multiple boards made of thermal insulation material and connected to the arms, each board having multiple separation members extending from two sides thereof and positioning recesses being defined between the separation members, each board having two holes and two secure slots which communicate with the two holes respectively, a width of each of the secure slots being smaller than a width of the block corresponding thereto so that the block passes through the hole and the neck being moved to be engaged with the secure slot to connect the board to the arm, the bosses urging the board, at least two electrothermal straps engaged with the positioning recesses and spirally mounted to the boards, wherein the base has a passage defined axially therethrough and a first tube and a second tube extend from two sides of the base respectfully, a separation tube has one end inserted into the first tube and the other end of the separation tube is mounted to the second tube of another base of the rack.