Method for controlling foam in pulp and paper industry

To eliminate or control foam, you can use one or more of the following methods:
(1) To reduce the effectiveness of foam stabilizers, chemical reactions or non-polar solvents can be used. Chemical defoamers can form unstable foam products through chemical reactions. This product has the effect of reducing the foam stabilizer, or adding a non-polar solvent that is insoluble in water, it will spread on the water surface to form a new surface. , Resulting in the bursting of the foam. However, these solvents are effective only for surface foams and not for foams that have been dispersed in water.
(2) In terms of reducing foam stability, methods such as increasing surface tension, reducing surface viscosity, or reducing hydrogen bonding can be used. There are many types of chemical defoamers, some of which have the above functions. As long as they are properly selected, the stability of the foam can be reduced, and the purpose of defoaming can be achieved.
(3) Use to form local weak points to burst the foam, such as to have a low surface tension or use a hydrophobic solid defoamer. In addition, there are coupling surfactants or polar solvents for replacing the foam forming body.