Dissolved air flotation (DAF) is a water treatment process that clarifies wastewaters (or the waters) by the removal of suspended matter such as oil or solids. The removal is achieved by dissolving air in the water or wastewater under pressure and then releasing the air at atmospheric pressure in a flotation tank basin. The released air forms tiny bubbles which adhere to the suspended matter causing the suspended matter to float to surface of the water where it may then be removed by a skimming device.
Features
• Small footprint, lower energy consumption; easy operation and simple management.
• High efficiency of air dissolving, stable treatment effects;
• This unit uses our GFA dissolved air System with ingenious structure. Its efficiency of air dissolving can reach up to 90%. Compared with traditional air system, our new dissolved air System has about one-fifth volume. What’s more, it has strong anti-clogging capacity,
• Use chain-plate skimmer, stable operation and high efficiency of scraping.
Working Principles
GF Type combined DAF consists of flotation tank, dissolved air system, reflux pipe, dissolved air released system, skimmer (Based on customer needs, there are combined type, traveling type and chain-plate type to choose), electric cabinet and so on.
Air flotation separation technology dissolves air into water at certain working pressure. In the process, pressurized water is saturated with dissolved air and is discharged into a flotation vessel. The microscopic air bubbles produced by released air attach to suspended solids and float them to the surface. forming a sludge blanket. Finally, it complete purifies the water.
Air flotation technology plays an important in solid-liquid separation. (simultaneously reduce COD, SOD, chroma, etc). Firstly, mix flocculating agent into raw water and stir thoroughly. After the effective retention time (lab determines the time, dosage and flocculation effect), the raw water enters into the contact zone where microscopic air bubbles adhere to the floc and then flows into the separation zone. Under the buoyancy effects, the tiny bubbles float the flocs to the surface, forming a sludge blanket. A skimming device removes
the sludge into the sludge hopper. Then the lower clarified water flows into the clean-water reservoir through the collecting pipe. Some of water are recycled to the flotation tank for the air dissolving system, while others will be discharged.
Application
Dissolved air flotation is very widely used in treating the industrial wastewater effluents from oil refineries, petrochemical and chemical plants, natural gas processing plants, paper mills, general water treatment and similar industrial facilities such as electroplating, food, slaughtering, brewing, tanning, printing, and dyeing, paper making.
Technical Data Sheet
Outside Drawing for Reference
Table 1 GF Type DAF (excluding reaction tank) outside drawing
Note: The above information is for reference only. Our company will reserve the modifying right of the above specification.Please ask for the actual installation dimension and piping layout before ordering based on the different sewage and water quality
Table 2 GF Type DAF (inluding reaction) outside drawing
Other GF type DAF except the above models can be designed and manufactured according to the customer need. For detailed parameters, please connect us.
Note: The above information is for reference only. Our company will reserve the modifying right of the above specification.Please ask for the actual installation dimension and piping layout before ordering based on the different sewage and water quality
MULTIPHASE MIXTURE DAF
DAF Introduction
Our multiphase mixture DAF, also called air-liquid mixing pump DAF, uses the multiphase pump (such as Japanese Nikuni, Germany Edur pump) to produce micro bubbles, without requiring of air compressor and dissolved air tank. Due to its special hydraulic parts design, the pump can fully mix up with the liquid in a highly dispersed state, like a dynamic mixer.
Features
• No need of air compressor and pressure vessel.
• Save operating cost, floor space and investment.
• Simple, compact and maintenance -free.
Working Principles
The performance of GDXF is mainly determined by the gas content in the multiphase mixture liquid when pump inhales liquid, it forms negative pressure at the pump inlet where air is inhaled through suction hole and liquid. Then air is dissolved into water by high speed rotating pump impeller. By adjusting operating points and solid-liquid proportion, it can achieve massive dispersed micro-bubbles or meet maximum carrying capacity.
Based on different pump specification, gas content in liquid can reach 30%. When this saturated water (over saturated water) flows into dissolved air vessel, it can instantly release high-density micro-bubble whose average diameter is less than 30 micron through release device after a certain period of time.
Finally, flocculating sewage mixes up with these micro-bubble after entering into the flotation tank, Then these micro-bubbles attach to the suspended solids and float them to the surface These suspended solids reply on the micro-bubbles to sustain the water surface, forming a floating layer on the surface of the unit, The floating layer is removed into scum tank by means of a skimming device.
Application
GDXF Type dissolved air flotation is suitable for:
• Disposal of oily waste water treatment in petrochemical industry.
• Oily waste water treatment and reinjection water in oil exploitation industry.
• Disposal of slaughter waste water in meatpacking industry.
• Grease and effluent treatment in dairy industry.
• The treatment of effluents generated by the pulp and paper industries.
• Oily waste water treatment in machinery processing industry.
Technical Data Sheet
Outside Drawing for Reference
GDXF Type DAF Schematic D
CAVITATION AIR FLOTATION
DAF Introduction
CAF (Cavitation Air Flotation), is a patented solid-liquid separation technology especially used for removing oil and grease, jelly and SS. By using of aerator, CAF’s special designed impeller can distribute the micro bubbles into the sewage evenly without any complicated air dissolving process. Then this will not have any blocking phenomena.
Features
• NO need of reflux pump, air compressor and pressure vessel.
• Save operating cost, floor space and investment cost.
• Simple, compact and maintenance-free.
• Especially suit for oily wastewater treatment.
Working Principles
CAF (Cavitation Air Flotation) is composed of aerator, flotation tank, skimmer and electric cabinet. The aerator will generate air bubbles through its highly speed rotating motor by way of absorbing air and then this micro bubbles will be distributed in the sludge water tank via stainless steel bulk air impeller.
Utilizing the centrifugal force caused by high speed rotating driven impeller, aerator produces negative pressure and suck other gas into aeration port. Then the air is released again by submerged aeration port. When the bores on the perforated impeller produce bubbles, high speed rotating impeller will cut bubbles into 30-100um tiny bubbles. Finally. flocculating sewage mixes up with these micro-bubble after entering into the flotation tank, Then these micro-bubbles attach to the suspended solids and float them to the surface. These suspended solids reply on the micro-bubbles to sustain the water surface, forming a floating layer on the surface of the unit. The floating layer is removed into scum tank by means of a skimming device.
Application
Cavitation air flotation is suitable for:
• Disposal of oily wastewater in petrochemical industry.
• Oily wastewater treatment and reinjection water in oil exploitation industry.
• Disposal of slaughter wastewater in meatpacking industry.
• Grease and effluent treatment in dairy industry.
• The treatment of effluents generated by pulp and paper industries.
Technical Data Sheet
Outside Drawing for Reference
GDXF Type DAF Schematic Diagram
SUPERFICIAL DAF
DAF Introduction
Our GQF Type Superficial DAF is an advanced quick-speed flotation system integrated with flocculation, flotation, skimming and mud scrapping, Based on the traditional flotation theory, we also use the “shallow theory” and “principle of zero speed” successfully. Thus our superficial air flotation is widely applied in waterworks removing alga, varec and other turbic water from nature lake and river; Industrial sewage treatment projects such as petro-chemical, textile, printing and dyeing, electroplating, tanning, food industry and other fields; Recycling useful material in sewage like fibre recovery on paper & pulp industry
Features
• Shallow effective water depth: 750mm—950mm.
• Short hydraulic retention time: 5- 10 min
• Large purification capacity, namely high surface load.
• Small footprint, light unit load, all prefabricated assembly, overhead installation of multi-layer combination mounting.
• Low cost of installation and maintenance, easy to clean.
• High purification degree, algae and other suspended solids removal rate over 90%, thickened sludge concentration can reach 35%.
• Our superficial DAF will use GFA Type dissolved air system with its ingenious structure. The GFA dissolved air system has the strong anti-clogging ability.
Structure and Working Principles
Air-floated separation technology is a very good way of purifying water from suspend solid by releasing pressed saturated air water to make its generated air micro bubble contacting with suspended floc fully, which will form flotation sludge to be scrapped out of water by its scrapper .
Our device is an advanced quick-speed flotation system with all flocculation, flotation, skimming, mud scrapping together under successful use of the “shallow theory” and the “principle of zero speed” to gain high efficiency.
In order to make up shortcomings of the traditional unit, we design raw water inlet and purified water outlet as movable to save bubble floating time of raw water, namely, while raw water is flowing into the tank, the pool pipe water flow opposite way to make raw water in the pool nearly in static condition, by this way, the bubble can float to the surface quickly like SS flotation speed (4-10 minutes), meanwhile, the purified water can be drained out when its pipe move here. Due to its compact round design with inlet and outlet pipes installed on rotating rack to generate centripetal moving with nearly zero speed, which will make the suspended solid fast floats on original water surface and then been purified within 3 minutes.
This equipment is cylindrical and compact in structure, including flotation tank, rotating water distributor, dissolved air release system, rotating rack, water collection device, scum skimmer, dissolved air system, reflux pipe, electric cabinet and etc. Inlet, outlet and sludge discharge outlet are all installed on the rotating area where water distributor, water collection device, dissolved air release system are connected to frame closely, rotating around the flotation tank center. This device provides module integrated equipment assembly by adopting both centralized and decentralized control system to realize the best operating condition.
Process Flow Diagram
Remarks: Due to the special construction of superficial OAF, it determines the strict request of the height. Ground level h; Concrete cross beam bottom elevation hl; Concrete cross beam bottom top elevation hl; Reaction tank top h3. Generally. if there is following requirements. special conditions can be talked separately. h3-h2 is more than 2200mm (Based on the site piping layout, there is few differences) hl-h is more than 2000mm (otherwise dissolved air system can’t be arranged under the DAF equipment.)
Main Technical Data Sheet
VERTICAL DAF
DAF Introduction
GSLF vertical DAF has the same working principle with other DAF. But for the structure, we have made some adjustment. GSLF type vertical DAF has cylindrical tank, using central water distribution and peripheral outflow.
The separation zone is better for sludge floating and thickening. For the small volume, it has been widely applied in WWTP reconstruction project.
Features
• Less land occupation.
• High surface load.
• Simple operation and easy maintenance.
Applied Range
Vertical DAF has been mainly applied in:
• Electroplating industry.
• Tannery industry.
• Dyeing and printing industry.
• Slaughtering and breeding industry.
• Other floating sewage treatment.
• (solid-liquid separation and oil-liquid separation)
Composite
Tank, dissolved air system, pipe system, skimming system, electric control system, ladder and platform.
Main Technical Data Sheet
The parameters and pictures listed are for reference only. Gongyuan reserves the right of continuous improvement. All parameters are subject to confirmation by both parties.
OTHER DAF TYPE
Sedimentaion DAF
Double- Effect DAF
Experimental DAF
CHAIN-PLATE SKIMMER
Overview
GLG Series chain-plate type skimmer is used for scraping and Skimming for various kinds of rectangle flotation tank
OIL SKIMMER
FEATURES:
• Excellent Oil Recycling Capacity.
Directional flocking fibre belt is made of long and short fibre, within which there is much space for oil storage. According to measurement, the proportion of recycling capacity of directional flocking fibre belt and steel belt with the same-length is 4 to 1.
• Long Service life.
The material of directional flocking fibre belt itself is anti-abrasion and anti-corrosion Except tor the high quality of the belt the space for oil storage is the space between fibre. When skimming oil the scraper will not directly touch the belt, so abrasion can nearly be neglected.
• Second Separation.
Floating oil slick processor can secondly separate recycled oil, greatly improves the purity of separated oil.
MICRO-NANO BUBBLE GENERATOR
Introduction
The independent-developed micro-nano bubble generator is consisted of micro-nano bubble generating device, diffusion device, shallow device, limit device, control device and etc. This system has been widely applied in aquaculture, landscape works. river improvement, water reuse, sewage treatment, gas-liquid mixing and other field. Combined with different air supply (such as air, oxygen, ozone, nitrogen, etc) and technique, it can realize high-efficient oxygen aeration, DAF separation, oxidative decoloration, nitrogen and phosphorus removal and other functions.
Application
• Minimal equipment: teaching demonstration, scan-scale tests and pilot experiment, integrated treatment unit.
• Large-scale equipment: quick purification and long-term operation of black-odor river, water purification process, reclaimed water reuse, standard purification, wastewater DAF treatment, new breeding and planting, etc.
Justin
Justin
Justin