1)Physical methods from the physical point of view, the methods for eliminating foam mainly include placing baffles or screens, mechanical stirring, static electricity, freezing, heating, steam, radiation, high-speed centrifugation, pressure reduction, high-frequency vibration, instantaneous discharge and ultrasound (Acoustic liquid control), etc., these methods have promoted the gas permeation rate at both ends of the liquid film and the discharge of the bubble film to different degrees, so that the stability factor of the foam is less than the attenuation factor, so that the amount of foam gradually decreases. However, the common shortcomings of these methods are that the use is strongly restricted by environmental factors and the defoaming rate is not high. The advantages are environmental protection and high reuse rate. (2) Chemical methods The methods of eliminating foam from a chemical point of view mainly include chemical reaction methods and methods of adding defoamers. The chemical reaction method of the foam burst process refers to the chemical reaction with the foaming agent by adding some reagents to form a substance insoluble in water, thereby reducing the concentration of surfactant in the liquid film and promoting the burst of the foam, but this method There are shortcomings such as uncertain composition of foaming agent and harm to system equipment due to the production of insoluble substances. At present, the most widely used defoaming method in all walks of life is the method of adding defoaming agent. The biggest advantage of this method is the high foam breaking efficiency and the ease of use. However, the search for a suitable and efficient defoaming agent is the key.