It is composed of a heating body ( 1 ), made from material resistant to
corrosion and high temperatures, with a cylindrical top and a spherical cap for a bottom, around which, in its outer upper part, is placed a plated
resistor, or heating
blanket ( 2 ), the action whereof will cause the heating of the heating body, in whose inner space the flask which is to be heated is placed. Said heating body has an upper
flange, by way of a circular hoop ( 3 ), which is fastened between two flat circular rings ( 4 - 5 ), made of a material with high
thermal insulation capacity, an upper cover ( 6 ) being placed on these rings, the central circular orifice whereof is completely in line with the top of the heating body ( 1 ). An insulating screen ( 8 ) is placed therein which goes around the whole of the heating body ( 1 ), laterally and below, all the inner space of the apparatus being filled with
wool or thermal insulating shavings ( 9 ). There is an electronic control module ( 11 ), acting from the exterior ( 11 a) of the
chassis.