PP air flotation machine

▍ Working principle

The working principle of a container-type dissolved air flotation (DAF) unit is based on "microbubble adsorption and separation" technology. Its core lies in generating a large number of microbubbles, which adhere to pollutants in the wastewater, forming a "bubble-particle" aggregate. This aggregate has a lower overall density than water, causing it to rapidly float to the surface under buoyancy, forming a scum layer that is then automatically removed. The entire process mainly includes the following two systems:

1. Dissolved Air System:

● Using a dissolved air pump (or a traditional dissolved air tank + air compressor system), air is forcibly dissolved in the return clean water under a certain pressure, forming dissolved air water. This process creates the key medium required for DAF.

2. Release and Separation System:

● The high-pressure dissolved air water enters the DAF tank through a special dissolved air release device. The pressure drops sharply the instant it enters, and the supersaturated air in the water is abruptly released in the form of extremely fine bubbles (typically 20-40 micrometers in diameter).

● These dense microbubbles fully mix and come into contact with the pollutants in the wastewater that have already formed flocs through the action of coagulants (such as PAC, PAM).

● After bubbles adhere to flocs, they form a "floc-bubble" copolymer, whose apparent density is much less than that of water, thus causing it to float rapidly.

● This copolymer accumulates on the water surface, forming a thick layer of scum. A chain-plate scraper or spiral skimmer installed on the surface smoothly scrapes this scum into the sludge tank, achieving continuous separation and removal of pollutants.

● The treated clean water collects from the bottom of the tank. A portion flows out through a collection pipe, becoming compliant water; the other portion is returned to the dissolved air system for preparing dissolved air water, thus recycling the system.

▍ Structural features

1. Integrated Container Design:

● The entire flotation system (including the flotation tank, dissolved air system, sludge scraping system, reagent tank, electrical control cabinet, etc.) is integrated into a sealed container made of PP sheet. Its compact structure and small footprint, resembling a complete "sewage treatment container," facilitates transportation and installation.

2. PP (Polypropylene) Main Body:

● Excellent Corrosion Resistance: PP material exhibits extremely high corrosion resistance to inorganic acids, alkalis, salts, and most organic solvents, completely solving the problems of rust and coating peeling associated with carbon steel equipment, resulting in a longer service life.

● Lightweight and High-Strength: The equipment is significantly lighter than comparable carbon steel or concrete equipment, reducing foundation load requirements and facilitating hoisting and relocation.

● Non-Toxic and Harmless: PP is a food-grade environmentally friendly material that will not cause secondary pollution to water quality, making it suitable for applications with high water quality requirements.

● Easy Maintenance: PP material is easy to weld and repair, and its smooth inner wall does not easily attract sludge, reducing cleaning and maintenance workload.

3. High-Efficiency Dissolved Air System:

● Employs a high-efficiency dissolved air pump or tank, ensuring high dissolved air efficiency and producing fine, uniform bubbles, guaranteeing high separation efficiency.

● Patented dissolved air release device: Stable and uniformly releases a large number of microbubbles, avoiding the formation of large bubbles and thus ensuring effective flotation.

4. Automatic Sludge Scraping System:

● Uses a chain-plate or spiral scraper driven by a reducer, ensuring smooth operation and adjustable speed. It effectively removes surface sludge without disturbing the separated sludge layer.

5. Fully Automatic Control System:

● Integrated PLC control cabinet enables fully automatic operation of the equipment, including the start-stop linkage of the water pump, scraper, and dosing device. Operation is simple and management costs are low.

▍ Product Advantages

1. High Treatment Efficiency: Microbubbles bind tightly to pollutants, rise rapidly, and have a short hydraulic retention time (approximately 15-20 minutes), achieving SS and grease removal rates exceeding 95%.

2. Low Operating Costs: High equipment integration and low power consumption; high-efficiency dissolved air system, saving air volume; high degree of automation, reducing manual monitoring costs.

3. Easy Installation: The equipment is shipped as a complete set; simply connect the piping and power supply for immediate operation, significantly reducing on-site construction work and time.

4. Corrosion Resistance and Long Lifespan: The PP material ensures long-term stable operation in harsh wastewater environments, resulting in extremely low maintenance costs.

5. Excellent Effluent Quality: Effectively improves sensory indicators of water quality, reducing the load on subsequent biological treatment units.

6. Environmentally Friendly: The fully enclosed structure effectively prevents odor leakage, improving the operating environment.

▍  Scope of application

This equipment is particularly suitable for treating wastewater containing fine suspended solids, colloids, grease, and fibers. Its main applications include:

● Food processing industry: Removing oil and suspended solids from wastewater from meat, seafood, dairy, fruit and vegetable processing, and beer and beverage production.

● Slaughterhouse and meat processing: Treating high-organic-load wastewater containing large amounts of grease, blood, and hair.

● Petrochemical industry: Pretreatment of oily wastewater to recover oil resources.

● Textile printing and dyeing industry: Removing fiber debris, dye particles, and colloids from wastewater.

● Paper industry: Recovering fibers and reducing white water concentration.

● Machining and surface treatment industry: Treating cold rolling wastewater and emulsion wastewater.

● Municipal sewage: Used in the pretreatment stage to remove some suspended solids and grease, reducing the burden on subsequent treatment processes.

● Other fields: Pretreatment of similar wastewater from the leather, pharmaceutical, and chemical industries.

▍  Summarize:

PP material container-type air flotation machines have become an indispensable key equipment in reclaimed water reuse and various industrial wastewater pretreatment processes due to their excellent corrosion resistance, efficient and stable air flotation separation effect, compact integrated design and low operating and maintenance costs.