Heating apparatus of tank type

Claim 1

A heating apparatus for a tank having a bottom wall and a peripheral wall extending from the bottom wall, the bottom wall and the peripheral wall each having an inner wall surface and an outer wall surface, said heating apparatus having heating means in the form of electrical heating resistors, said electrical heating resistors being embedded in a flexible material, the flexible material being applied onto the outer wall surfaces of the tank, said heating means comprising a first heating element having a substantially rectangular shape and being applied onto the outer surface of the peripheral wall of the tank, and a second heating element having a substantially circle-sector shape and being applied onto the outer surface of the bottom wall of the tank, said first and second heating elements each containing the electrical heating resistors, said first heating element and said second heating element being connected to each other by means of a bridge, said bridge being made from a flexible material, said bridge containing electrical connections between the electrical heating resistors contained in said first heating element and the electrical heating elements contained in said second heating element, the tank having an outer perimeter, said first heating element having a length which is a half of the outer perimeter of the tank, said second heating element being substantially a sector corresponding to a half of the outer surface of the bottom wall of the tank, and said first heating element and said second heating element being at least two in number on the tank.