Filtration systems function by forcing cleaning fluid through Filter Cartridges, or Filter Bags. These devices strain the cleaning fluid, capturing all particles of a given size before the fluid is returned to the ultrasonic cleaning tank. This action removes particles from the cleaning fluid, allowing for longer use and reduced maintenance on the cleaning tank. However, filtration systems must be properly engineered and designed to work most effectively.

2 different general styles of Filter Housings are available. The Cartridge Filter Housing, the most common variety used for ultrasonic cleaning tanks, houses a replaceable filter cartridge. A Bag Filter Housing, the more expensive option, houses a Filter Bag which can capture greater volumes of contaminants before requiring replacement, making these housings the preferred choice for buffing and polishing compound removal applications, or any other application which involves the removal of considerable amounts of particles from the parts being cleaned.

Filter housings also include Pressure Gauges which are used to indicate when filter bags or cartridges may require replacement. As the filter media becomes clogged, pressure begins to build inside of the filter housing as the pump tries to force the liquid through the media. When the pressure builds to the maximum pump output pressure, the filter media must be changed.

Filtration systems must be properly engineered and designed to work most effectively for a given application. Filter cartridges and bags are sold based on the size of the openings that the liquid must pass through, and is typically rated in microns. The smaller the pore size of the filter media, the greater the number of particles the media will trap. If the pore size selected is too small for the amount of particles in the cleaning fluid, the filter media will clog rapidly, leading to a system which requires continuous maintenance, and replacement of filter media. If the pore size selected is too large for the type of particles found in the cleaning fluid, not enough particles will be captured, which yields an in-efficient filtration system. The filter system must include the appropriate filter media pore sizes to provide the benefits listed above without producing excessive maintenance.

Care must also be taken to reduce the turbulence created by the filtration system in the ultrasonic cleaning tank. As discussed in the Ultrasonic College section on Fluid Circulation, fluid turbulence will drastically reduce or eliminate all ultrasonic cleaning action. As a result, filter systems for ultrasonic tanks are typically only operated when parts are NOT being cleaned. A less favorable option is a Flow Control Valve which can be used to reduce fluid turbulence. However, by reducing the fluid turbulence, you simultaneously reduce the effectiveness of the filter system. A properly-designed filter system will continuously sweep the bottom of the tank, pushing the contaminants towards the filter intake. By reducing the filter system flow, this sweeping action is reduced and greater volumes of contaminants will be found at the bottom of the tank rather than inside of the filter housings.

The flow pump used in the filtration system purchased must produce enough pressure to force the liquid through the filtration media, and must be compatible with the cleaning agent in use. Zenith filtration systems utilize either a stainless steel centrifugal pump, or a magnetic-drive seal-less NORYL pump for fluid compatibility. For those applications requiring filtration to sub-micron levels, a high-pressure Positive Displacement Pump is used to ensure that enough pressure exists for effective filtration.

The plumbing used in a filtration system must be strong enough to resist pressure buildup, and must be compatible with the cleaning fluid in use. Zenith offers both PVC and rigid stainless steel plumbing options to satisfy any filtration requirement.

Zenith Mfg. & Chemical Corp.
85 Oak St.
Norwood, NJ  07648-0412
800-432-SONIC (7664)
201-768-6999
sales@zenith-ultrasonics.com