oil diffusion pump of heater and heating power

Compared with the diffusion jet pump, the pumping capacity and maximum outlet pressure of the oil diffusion pump are much lower, so the heating power of the pump is also relatively low. The boiler diameter of oil diffusion pump is usually equal to (or less than) the pump port diameter. The heat load of oil diffusion pump boiler with pumping speed greater than 500l/s shall not exceed 2-2.5w/cm2

In the oil diffusion pump, the power lost by oil evaporation is usually 60%-70% of the total power, and the rest is the power to compensate for various heat losses. The losses in the diffusion pump mainly include the following aspects: heat conduction from the heater surface to the outside through the boiler wall (accounting for 20%-25%); Heat conduction from the hot boiler to the internally cooled pump body along the pump wall (accounting for 10%-15%); The radiation from the guide pipe surface to the pump wall and the heat conduction of the mixture of gas and steam from the guide pipe to the pump wall (5%-10%). If the pump has a good structure, the heat loss can be reduced to 10%-15% of the total power. For example, the heat loss can be significantly reduced by insulating the heater and boiler of the pump. If a closed heater is used, and there is no air layer between the bottom of the pot and the heater, the heating power can be well utilized.