Product Focus: No-Foul Filtering

March 4, 2014
Cooling processes and equipment that regularly require the use of seawater and other low-quality water from sources such as rivers, lakes and canals are essential.

Self-Cleaning Filters Help Prevent Industrial Cooling Processes, Equipment from Clogging

Cooling processes and equipment that regularly require the use of seawater and other low-quality water from sources such as rivers, lakes and canals are essential. However, preventing particles in this water from causing excessive fouling and expensive downtime can often pose a challenge.

Bernoulli filters provide pre-treatment of raw water like surface or seawater by reducing the load of particles in natural water sources.

As such, Bernoulli System's multi-basket self-cleaning BMG-range filters reduce a number of elements in these natural water sources and protect sensible process equipment from clogging and fouling. By using multiple smaller filter baskets in one filter body, the BMG-range systems offer fine filtration down to 100 microns, even at large capacities.

Over the years, there has been an increasing demand for larger filters capable of handling greater quantities of cooling water. Bernoulli filters serve as pre-filters and act as an additional protection for finer filtration technologies such as ultrafiltration and multimedia filtration. With desalination, the systems also act as pre-filters before reverse osmosis (RO), where potable water is produced from saline water for domestic and municipal purposes.

Bernoulli filters are pneumatically operated, making the automatic cleaning process simple and reliable, with very little mechanical wear. Likewise, they are supported by a control panel with a programmable logic controller (PLC) equipped with an HMI color touch screen, as well as a flushing valve including an actuator and a differential pressure sensor. The filters can also be installed either horizontally or vertically, given its flexible nozzle orientation. Since they operate as pressure filters, they are always installed downstream of the feed pump.

The filters work on the principle that an increase in the velocity of the flow of a liquid gives rise to a drop in pressure. A specially-designed piston is introduced into the filter basket, which creates an increase in the velocity of the flow between the piston and the wall of the basket. The resulting drop in pressure vacuums away the particles that have attached themselves to the inside of the basket. The impurities are then flushed out through a valve, and problems due to the clogging of the basket are avoided.

The flushing sequence is conducted in two steps. First, the valve opens, and large particles are flushed out. Second, the piston moves twice into the basket, removing the particles adhering to it. The flushing sequence is initiated by either a timer or a differential pressure switch.

Another feature is the ability to obtain log data, which is valuable during troubleshooting. Further, the PLC is easy to adapt. For example, one PLC can be used to control multiple filters. The growing demand for distance control of process equipment can be satisfied with the PLC, which can easily be connected to a PC. This enables service engineers to fine-tune parameters for process optimization.

The scope of applications ranges from pre-filtration in water treatment to the protection of plate heat exchangers and sensitive process equipment such as spray nozzles. The BMG-range filters are used in a variety of industries ranging from power generation, petrochemicals and HVAC to steelmaking, aquaculture, pharmaceuticals, pulp & paper, and food & beverage.

Bernoulli System's multi-basket self-cleaning BMG-range filters consist of four models, DN400 (16 inches) to DN800 (32 inches), covering a capacity range up to 8,000 m3/h, and are encased in glass fiber reinforced polyester (GRP). For more information, visit www.bernoulli.se/en.

More Industrial WaterWorld Articles
Past IWW Issues