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How to add defoamer/antifoam and Tips using defoamer


How to add defoamer/antifoam and Tips using defoamer

Adding Method

1) Gap addition- common method

If it is not continuous foaming and the foaming is not severe, the antifoaming agent may be added once or periodically. Since the amount of the antifoaming agent added is small, in order to make the antifoaming agent uniformly dispersed, it should be added in a place where the foaming liquid is drastically shaken. Many occasions can be added by hand. If the blister is violent or for rapid defoaming, it can be sprayed with a spray gun.
If foam is allowed to exist within certain limits, just to prevent excessive foaming, an insoluble, high-efficiency silicone paste defoamer may be applied to the upper edge of the wall of the container or applied to a metal mesh or other textile mesh. Above, cover a certain position of the container. The foam layer is exposed to the silicone defoamer and can be broken, thereby blocking the foam from overflowing. Not enough to add once, you can join multiple times or join regularly.

2) Continuous addition - large scale of production

After the defoaming agent is added, defoaming also begins to fail from the beginning. Intermittently added defoamers are continuously lost, and when the defoaming agent is insufficient to control the foam, additional addition is required.
Obviously, if we master the necessary consumption of defoamer, we can achieve continuous addition, which can save the amount of defoamer and avoid meaningless consumption. Continuously added, the defoaming agent can be added into the high-position tank above the equipment, and the high-position tank is placed on the equipment to be vigorously shaken, and continuously added to the equipment according to the actual amount of the defoaming agent. If the equipment is a pressure system, it can be added with a metering pump.

3) Self-control added - more advanced

Any foaming liquid does not necessarily foam from beginning to end. When there is foaming, the amount of foam does not have an accurate pattern. The defoamer is added to supplement the consumption, and it is not necessary to add it when it is not foaming. Therefore, a self-controlled addition method can be adopted to automatically add an antifoaming agent according to the foaming aura. The automatic control device should be designed according to the characteristics of various devices, and add some necessary instrument control. More suitable for self-controlled addition, large chemical distillation towers, absorption towers, polymerization tanks and so on.

Tips:

1) Dilution

The amount of foaming agent added is generally small, the defoaming agent added to the foaming system has an active content of from 1 ppm to 100 ppm, and the food-grade defoaming agent is generally recommended to have a dosage of 10 ppm. Such a small amount of defoamer must be diluted to be quickly dispersed. Bulk and solvent defoamers must be diluted with a solvent or a liquid in a foaming system; an emulsion defoamer, diluted with water or a foaming medium.

2) Temperature

The emulsion type defoamer can only be diluted with cold water, and the hot water dilution will break the emulsion.

3) Dilution concentration

The amount of diluent added should preferably be in accordance with the instructions on the product information. Usually add 3 to 5 times the dilution, up to 10 times. For the bulk type defoamer, it is generally diluted to an active content of 5 to 10%. If the foaming system has a good stirring and dispersing device, the emulsion type defoaming agent can be directly added without dilution.
The concentration at the time of dilution is high and the dispersion is poor. When the concentration is too low, the amount of addition is increased, and many unnecessary components are added to the container to reduce the defoaming effect.

4) Application period

Since the diluted emulsion becomes low in surfactant concentration, the emulsion is extremely unstable and quickly stratifies and fails. The application period is only 2~4h, so the defoamer should be used now.

5) Add amount and timing

The amount of defoamer added and the timing of addition should be determined by the user after testing. Can not be carried out blindly, otherwise it will cause unnecessary waste.
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