PTFE Mother Liquid Steam Purification via Falling Film Absorption

The patent introduces a falling film absorption tower as an intermediary device between the concentration kettle and the discharge point. This tower uses a liquid film flowing down the inner wall to absorb and separate emulsifiers and foam from the vapor phase, preventing them from contaminating the final product and reducing water consumption. The absorption tower acts as a mediator that resolves the contradiction by enabling efficient separation without requiring large quantities of fresh water for washing and treatment.

The patent employs a defoaming pot filled with porous materials (such as ceramic foam or porous plastic) to break up foam structures and facilitate gas-liquid separation. The porous structure provides numerous nucleation sites for bubble formation and collapse, effectively destroying the foam matrix that causes emulsifier carryover. This allows the system to maintain high production efficiency while minimizing water consumption by preventing contamination at the source.

The patent extracts the harmful foam and emulsifier carryover from the vapor phase using the falling film absorption tower. The liquid film in the absorption tower selectively absorbs emulsifiers from the vapor, separating them from the stable emulsion in the concentration kettle. This allows the system to maintain emulsion stability with necessary emulgators while removing the harmful foam entrainment that would otherwise pollute the absorption tower and consume water resources.

The patent converts the harmful effect of emulsifiers (which cause foam entrainment) into a beneficial separation mechanism. The falling film absorption tower utilizes the presence of emulsifiers in the vapor phase to drive the absorption process, where the liquid film absorbs these emulsifiers and returns them to the concentration kettle. This transforms the harmful foam-causing property into a useful mass transfer driving force, maintaining product stability while eliminating pollution.

The patent replaces conventional mechanical separation systems (such as centrifugal separators or filtration systems that require large amounts of water for cleaning and operation) with a thermal-mass transfer-based falling film absorption tower. This tower uses vapor-liquid equilibrium and mass transfer principles to achieve separation, eliminating the need for water-intensive mechanical separation processes while maintaining high product purity.

The patent exploits phase transitions (vaporization and condensation) to achieve separation. The concentration kettle vaporizes water and emulsifiers, and the falling film absorption tower condenses the vapor while selectively absorbing emulsifiers into the liquid film. This phase transition-based separation achieves high product purity without requiring large quantities of fresh water, as the system primarily uses the vapor itself and recycles the absorbed liquid.