to find out more about our products.
Our knowledgeable, skilled employees are ready to help you in your quest for cleaner water.
Dissolved Air Floatation (DAF) Technology:
Each industry generates different types and characteristic wastewater. Each has unique treatment problems. Considerable
study and supporting information must be analyzed before deriving the best solution to any wastewater treatment problem.
To identify and eliminate would-be difficulties, a comprehensive wastewater study is often warranted. This is an up-front
cost that must be recognized in order to manage all potential scenarios and to minimize future costs. DAF Corporation offers
these services.
Dissolved air flotation (DAF) or micro bubble flotation technology is an effective, economical process for treating
wastewater. A DAF clarification system is comprised of three basic components: 1) process equipment, 2) chemical
conditioning, and 3) the dissolved air or micro bubble process. Each component is crucial to the operation of a DAF
clarification system.
A dissolved air flotation (DAF) clarifier separates suspended solids in wastewater. DAF clarifiers can be round or rectangular tanks. All DAF clarifiers have some internal mechanical components intended to speed up the removal of the suspended solids in the wastewater. Dissolved air flotation technology compared to sedimentation clarification technology, is much more cost effective, lower engineering design costs; lower installation cost; one-third the process time; and overall just a more effective technology. DAF clarifiers are excellent for removing fine suspended solids and for cleaning up water clarity problems. DAF clarified water is excellent for recycling, or for discharging to the city sewer system. It is important to understand DAF clarifiers need to receive wastewater with a relatively consistent flow and a stabile wastewater loading. It is essential that upstream wastewater mixtures be monitored, controlled and analyzed daily before entering a DAF clarifier. From experience we have seen some customers’ wastewater change drastically within hours, because of different types of wastes dumped into U drains that were not accounted for. There may be a need for rotating screens or equalization tanks ahead of the DAF clarifier. Pre-screening is used to remove large solids before the influent wastewater is pumped into an equalization tank. If an equalization tank is utilized, it should be equipped with some type of mixer and a cone bottom to aid in settling of the heavy, non-floatable solids. Coagulation mixing tanks and tube bundles are also common equipment ahead of DAF clarifiers. If coagulating and flocculating chemicals are added to the influent, they need mixing and retention time. Extreme ups and downs in water temperature and pH can also impact performance of a DAF clarifier. With an oily waste in the wastewater an oil-water separator may be needed ahead of the DAF EQ tank. Pipe sizing needs to be engineered correctly. Optimum DAF performance and chemical cost savings will be achieved when all necessary DAF auxiliary equipment is engineered and field piped properly. A well designed DAF treatment system will lead to lower capital costs and a small plant foot print.
If you have any questions or a possible need call DAF Corporation at 920-766-6052 USA
Chemical Conditioning for DAF Clarifiers:
Chemical conditioning and additions are not always needed with DAF clarifiers. When used, chemical conditioning promotes
the removal of suspended solids from the wastewater. Innovation and expertise are guaranteed by a close collaboration with all
customers by DAF Corporation. Customers have the opportunity to utilize our DAF water clarification lab resources located in
Kaukauna, Wisconsin, USA. Customer wastewater samples are sent to our lab and analyzed. Our lab jar tests identify the most
cost effective coagulant/flocculant chemical program or that no chemical additions are needed. There are several approaches
available for conditioning wastewater. DAF technology may not be the most efficient and cost-effective treatment technology.
A lab test study will determine this fact. DAF wastewater lab tests also tell us the proper chemical treatment, proper mixing
times, along with a good understanding of how and where to locate the chemical injection points in the piping system ahead of
the DAF clarifier. Lab studies identify approximate operating costs and wastewater cost savings. All this information is very
valuable and the cost money to accumulate. DAF Corporation for a small fee can help you if you have a need.
For more information call DAF Corporation at 920-766-6052 USA
The DAF - Air dissolving tube (AMT) - A Micro Bubble Generator
Wastewater influent enters the DAF clarifier mixed with fine micron bubbles. To attain a high solids removal rate, it
is important to have excellent and abundant fine micron bubbles all equal in size and to have minimized all water
turbulence in the DAF clarifier tank. A key factor for maximizing the efficiencies of the DAF clarifier is the
generation of all equally sized micro bubbles with no coarse air bubbles. Equal size fine bubbles, 20 to 50 micron
size will give the suspended solids an equal and steady rise rate of 10 to 12 inches per minute to the tank surface.
Large bubbles, also called coarse air bubbles, coalesce with small bubbles, making even larger bubbles. This bubbles
will race upward and percolate to the tank surface. Large bubbles lower performance efficiencies by more than 50%.
There is no better air dissolving system that we know of in the world for generating billions of cost efficient, all
equal in size micron bubbles with no coarse air bubbles than our DAF Air Mixing Tube (The AMT).
Our AMT tube uses a small amount of returned clarified water from the DAF clarifier. A small recycle pump pumps this
clarified water thru our air dissolving tube. Our AMT pressurizes it and saturates it with a small amount of compressed
air at approximately 80 psig. The AMT piping system returns this water to the DAF clarifier as pressurized water saturated
with dissolved air. In a plastic pipe it is totally clear looking water. When it passes thru a special designed pressure
expansion release valve, it is released into the tank where it comes back into contact with normal atmospheric pressure.
Fine micron bubbles spontaneously boil out of the recycled water solution. All these billions of equal size fine micron
bubbles attach themselves to the suspended water particles in the wastewater causing them to rise and float to the tank
surface. These fine particles form a firm surface sludge mat. The amount of clarified recycle water returned to the AMT
varies with each application. DAF clarifier capacities are based on flows and loadings of total TSS in the wastewater to the
DAF clarifier. One major difference of our AMT from all others is it produces consistently all equal size air with no coarse
air bubbles, while it utilizes only one-third the electrical motor pump hp, compared to a cavitating atmospheric pump.
We have learned from retro fitting old DAF competitors’ clarifier systems, DAF Corporation’s DAF AMT air dissolving
tube will increase any old DAF clarifier efficiency by more than 50%, if hydraulicly the existing clarifier piping
system will handle this increase in flow. DAF Corporation has many retrofits installations that paid back their
installing costs within months of their installation. We know of no other dissolved air system that can meet our
AMT performance bench marks. If you need a dissolved air (AMT) system upgrade or replacement of your old DAF clarifier,
give us a call.
Dissolved Air Flotation technology may be utilized cost effectively for the following applications:
Phosphorus removal; paper fiber recovery; chemical; pharmaceutical; refineries; breweries; dairies; oil and gas; agricultures run off; food; bakeries; poultry; fish processing; meat processing and meat packing; rendering plants; slaughter houses; potato processing; vegetable oil processing; canning water; soap industry; starch removal; laundries; textile effluent; ballast water; car wash operation; heavy metal removal; sludge thickening; membrane system pre-treatment; primary clarification; secondary clarification; water recycling; turbidity color; algae bloom control; and crytosporidium removal in potable water.
For more information call DAF Corporation at 920-766-6052 USA
DAF CORPORATION
Kaukauna, Wisconsin, USA
Telephone: (920) 766_6052
Facsimile: (920) 766_6054
e_mail: daf@execpc.com
