This product is mainly used for the pre-sintering of tetrafluoro powder, and it can also be used for drying and baking other workpieces with large self-weight. This product has the characteristics of good thermal insulation performance, high temperature control accuracy, wide temperature adjustment range and beautiful appearance. Through reliable dual circuit design and dual electrical control, it is impossible to lose control and thus effectively ensure the safety of the product. The box is equipped with a hot air circulation system, so that the forced convection of the hot air can obtain the ideal temperature effect. This product has a reasonable structure, the shell material is made of high-quality cold plate, the inner tank is made of stainless steel, and the box body and bottom are made of channel steel frame structure. Aluminum silicate cotton is used as insulation material between the shell and the working room, the electric control part is located on the left side, the heating element is on both sides of the inner tank, and there are enough gaps on the left and right sides, so that the hot air can be forced in the box. Convective circulation, the rear side of the box is provided with an air intake and exhaust port.