The Guide to Bernoulli Filters

To see our full range of Bernoulli Filters available in Australia click here: Bernoulli Filters

Clean water is vitally important in the industrial world during the process of production for diluting, washing, fabricating, or cooling the equipment used for the manufacturing of their products. Even though water that is free from impurities is a necessity in the production process, it is not enjoyed by everyone around the world. Because modern water supplying sources are often strongly polluted. Hence a good water filtration system is a mandatory investment in order to enjoy a safe industrial water supply for the production purpose.

Purification of water for human consumption purposes as well as industrial purposes is vitally required in order to remove suspended solids, biological contaminants (algae, bacteria, fungi), chemical contaminants (toxic pollutants), and gases. Therefore, aforementioned pollutants are removed by physical (filtration, distillation, sedimentation) chemical (chlorination, flocculation, ultraviolet light), and biological processes (active carbon, sand filters) in order to enjoy safe water for consumption.

Why it is called the Bernoulli filter?

The cleaning process of the filter works according to Bernoulli’s principle which was born long ago by combining, velocity and height of fluid at one point along with its flow. It states that an increase in a fluid’s flow velocity gives rise to a drop in static pressure. This fascinating concept is utilized in the Bernoulli filter‘s cleaning mechanism. The distinguishing feature of this filter is, either it is single or multi, the filter consists of a disc mounted on a pneumatic cylinder, which allows contactless cleaning of the filter. The sequence of filtration is totally automatic and continues even at the flushing stage. Some special features such as having very few moving parts, and lower flushing pressure makes Bernoulli filter doubtlessly unique filters in the industry.

In the late 80s, Ulf Steiner and his research team develop an automatic and self-cleaning filter for the protection of Plate Heat Exchange(PHE). The clogging issue of PHE led him to invent this filter with unique features. This filter has a unique design for water filtration. Moreover, these filters have only a few moving parts and these filters can be readily used for corrosion-free seawater filtration.

Bernoulli filters are designed with fully automated self-cleaning filter options where they can continuously perform water filtration in a pressurized environment. During the filtration process, it readily removes debris coming into the system from process liquids as well as from a variety of natural water sources such as a lake, river, sea, etc. Since this is a corrosion-free filtration system, seawater can be filtered without hesitation. Bernoulli filters always act as pressure filters and are always installed at downstream of the feed pump.

Operation of the filter

This can be divided into 3 parts;

Normal operation

Water enters the system through the inlet with impurities. There the water flow turns 90° and filtration occurs here when the impure water passes through the filter basket. At this stage, the pressure inside the filter basket at the outlet end will be higher than the outside pressure. Hence Particles larger than the filter will remain in the filter basket. Finally, the clean water flows out of the system through the outlet of the filter. It should be noted that during the normal operation of the Bernoulli filter, the cleaning piston is mounted at the top of the filter basket and the flushing outlet is closed.

Flushing

The flushing process starts once the debris has built up to 2/3 of the height of the filter basket height. It is initiated by a timer or a differential pressure switch and the filter basket is cleaned by the flushing operation.

The Bernoulli cleaning principle

During the cleaning phase of the filter, a disc that enters the basket performs the job of basket cleaning. At this cleaning, stage water is passing through a pre-determined gap between the basket and the disc by increasing the flow velocity locally around the disc while reducing the static pressure. This happens according to Bernoulli’s principle which has been discovered long ago. The lower static pressure around the edge of the disc creates a “vacuum cleaning ” effect on the basket. This unique self-cleaning feature of Bernoulli filters offers a competitive edge in the industry. These filters are equipped with a double supervision system which includes a differential pressure switch and a timer for the flushing process. The differential pressure switch can sense the clogging rate and control the flushing process.

Why the Bernoulli filter is known as a non-interruption filter?

One plus point where the Bernoulli filters attract a large audience is, its ability to continue the filtration process even when the filter is in the flushing mode. As the piston travels only about 2/3 of the length of the filter basket, the normal cleaning process can be carried out without any disturbance. Another unique feature is, no matter if the filter basket is cleaned or it is filled with debris particles or the filter is being flushed, the pressure drop over the filter is steady. This gives the idea of an effective open area of the filter which is the area in the wall of the filter basket that allows filtration divided by the total basket wall area

Typical applications

The main job of the Bernoulli filter is to capture the suspended solids in the source water.

The range of applications varies from pre-filtration in the water purification process to safeguard the PHEs and other downstream equipment such as spray nozzles. These filters are used in wide spectra of industries such as

Petrochemicals
power generation
aquaculture
pulp and paper
steel making
Pharmaceuticals
Food and beverages

Advantages of using Bernoulli filters

Requires only a low washing pressure
Can be easily installed
Maintenance is easy
Have only a few moving parts
Pressure is stable in both clean and dirty conditions.

Our products cover a range of Bernoulli Filters that allow for the contactless cleaning of the filter

Manual Bernoulli Filter and Automatic Bernoulli filters
Multi Basket Bernoulli Filter

Thanks to the use of multiple filter baskets in one filter body, fine filtration down to 100 microns are achievable, even at high flow rates. This means that one single multi-basket unit is capable of doing the work of multiple smaller single basket units. The result is a space-efficient installation that requires less piping.

Single Basket Bernoulli Filter

This product line was introduced in order to meet the tough corrosion challenges faced by products operating with seawater. With its design in GRP (glass fiber reinforced polyester) the filter benefits from material durability and large weight savings. In this product line, capacities of up to 6400 m3/h can be supported.

Centrifugal Oil Water Separators(cows) Eliminator
Centrifugal Oil Water Separators(COWS)

It is a water separator and fuel filter for HSD/LDO/Hydraulic oil, etc. An entirely new multistage centrifugal system ensures a 100% solution to the problem of water/moisture and particulate in fuel.