The ClearFox flotation plant is fully automatic. A specific, clog-free helical rotor pump leads the water from the collection container (collection tank or skimming tank provided by the customer) to the reactor.
The wastewater flows through a pH-regulation section where pH-fluctuations are compensated. Then, wastewater flows continuously into the reactor. Additives are developed in a polymer preparation station in order to aid the flocculation and flotation process.
These are mixed fully automatically into the inflowing waste water with flocculators. A multiphase pump saturates the outlet of the water continuously with air, which is then recirulated into the reactor. The pressure release causes a flotation of the floatable particles. These accumulate in the upper section of the reactor and are separated by a self cleaning process, or with a scraper for special applications. Flotation sludge is removed via a cone-shaped opening with compressed air.
The plant is fully automated and depending on the waste water flow, a high quality effluent quality is achieved at all times. The system is very robust, and uses no clearing devices with movable chains or scrapers (needing lubricants etc.), that require constant maintenance.
The Systems have proven their reliability in many industries over the years, particularly in the food industry.
The Cleaning-efficiency depends on how high the degradation rate of the waste water is and operator behavior.
The effluent is largely free from fats and purified to an indirect discharge quality, pH 6.5-7, COD 1.500 mg / l, BOD 1.000 mg / l, TSS 500 mg / l. There is no change in temperature as a result of the process, and the effluent quality is suitable for biological post-cleaning.
Typical cleaning performances in the milk / meat industry in the DELIVERY / PROCESS are as an example [mg / l] COD ZU: 3000-7000 / AB: 1000-1500, BOD ZU: 2000-3500 / AB: 700-1000, TSS ZU: 300-700 / AB: 250-500
The DAF System includes:
- flotation reactor
- feed pump eccentric screw for inflow
- feed pump eccentric screw for sludge feed
- small interim sludge storage tank
- dosing / mixing line
- polymer mixing station
- dosing pumps (2 x)
- suction lances for chemical canister
- multiphase pump
- pH neutralization
- room aerator and heater (frost protection)
- control unit
If not installed in a container, the scope of supply consists of three parts that can be set up freely and are mounted on skids. These parts (pump station, flotation station, dosing station), as well as the control cabinet, can be easily transported with forklifts.
The base area for the system components must be firm and level (foundations), the environment dry, covered, dew protected; in closed structures with multiple air changes according to the regional regulations.
In order to regulate the pH in the water, acids or alkalics are added into the system. The system also has a metering system for fission products (flocculant) and polymer (flocculant-help). The specific consumption is determined in the laboratory and this is optimized by us after the start up of system.
In the ClearFox® dissolved air flotation system, fats and oils along with other dissolved substances which are extracted, are removed from the wastewater as flotation sludge. The resulting amount is dependent on the concentration of such substances in the wastewater. It can be assumed that about 40 to 60 liters of flotation sludge per m³ of wastewater are produced at average concentrations. This is approximately 4 to 6 % of the volume of the waste water entering the DAF system.
The flotation sludge further dehydrates during storage, thus the longer it is stored, the less water content the sludge has. It is recommended to use enclosed structures /systems to avoid odour problems.