The defoamer should be tested before it is used

When using defoamer, it should be tested first, otherwise it will not reach the ideal effect due to improper selection, or even produce certain harm. We can conduct qualitative or quantitative testing on the properties of defoamer according to the actual needs. Then what are the specific ways of defoamer testing? Here are some examples for you.

image9-29

Firstly, measuring cylinder. The simplest and most common method is the measuring cylinder, in which 50ml foaming liquid is added into the 100ml measuring cylinder with a plug. After shaking the bottle up and down 20 times each time, the foam height and defoaming time are observed by standing.

Secondly, spray test. Spray bubble solution to make bubbles, and then add defoamer to determine the defoaming effect according to the defoaming time.

Thirdly, circulating pump test: put the bubble solution in the closed loop for circulating flow, add the defoamer for stirring, and measure the foam height.This method is to measure the quantitative evaluation of anti-foaming performance under dynamic conditions of agitation, emulsification and shearing. When the solution circulates in a closed loop, the time required to reach a certain foam height is measured to evaluate the anti-foaming efficiency.

Fourthly, density meter: density meter was used to measure the density of the foaming liquid mixture. The difference between the density value and the density of the foaming liquid before stirring was used to represent the foaming amount. The greater the density difference was, the higher the air content in the foaming liquid mixture was, the greater the foaming power was.The difference between the foaming amount of the blank pulp and that of the added defoamer is the anti-foaming amount, and the anti-foaming rate of the defoamer is obtained by comparing with that of the blank pulp.


Post time: Sep-29-2019