Dry Solids & Clean Liquid...

Coolant Filtration: Oil, Water and Synthetic

 How the Oberlin Coolant Filter Works

 The idea is to pass liquids contaminated with solids through media, trapping the unwanted solids in, then on, the media. The goal for the most economical filtration cost is to lengthen the filter’s cycle time. This maximizes the quantity of the unwanted solids per area of media to reduce media costs. Long cycles means the filtration process is working with fewer interruptions for media changes. This increases the capacity of a filter. Smaller filters cost less and take up less space than larger filters. As the unwanted solids build up on the media, the flow of the liquid is impeded. Unless the liquid is highly pressurized, the flow of the liquid through the filter will drop quickly and not satisfy the flow capacity required.

 Oberlin filters pressurize the liquid by pumping it into a chamber whose only outlet is through the unwanted solids on the media. The pressure is limited only by the size of the pump, not by atmospheric pressure. 30-40 psi is typical of an Oberlin filter. This is about three to four times more pressure than gravity or vacuum filters can develop. The time it takes to reach 10 psi is much less than the time to reach 30-35 psi in many applications. 

Oberlin Cleanable Belts – “Paperless Filters”

Oberlin has been building paperless filters for over 25 years. Our cleanable belt systems have been saving customers thousands of dollars annually in media costs. In the case of a change in application or process, all Oberlin pressure filters are engineered for easy conversion for media utilization.

 Large Central 500-6000 gpm systems

Oberlin Tubular Filter

 In some situations the coolant doesn’t filter easily. For example, honing may only filter at a flux rate of 3 gpm/ft2. If many hones are involved, a large filtration area will be needed. In these cases we may recommend a tubular or candle type filter. It is a pressure filter also, but the filtering surface is on the outside of wire mesh tubes hanging vertically in a vessel. Hundreds of tubes can be contained in one vessel resulting in hundreds of square feet of filtering area. These tubes are usually precoated with a filter aid. The tubes are cleaned by backflushing with clean coolant. The system consists of a tubular filter, tanks for both precoat, backwash, dirty coolant and clean coolant, and an Oberlin Pressure Filter to dewater the backwash.

 Some plants will not allow the use of silica based filter aids like Diatomaceous Earth (DE) However, recently fresh water based DE is available which does not contain any free silica and is non-hazardous.

Oberlin Tubular Filter

High-Performance Filtration

When your need is for 100% filtration, an Oberlin high- performance stand-alone system will provide you with a continual flow of the highest quality clean coolant. Installing an Oberlin high-performance pressure filter is your assurance that your machine tools always receive clean coolant and never need to stop for filter cycling. How a high-performance system works: used coolant flows by gravity or is pumped into the dirty compartment. From there, the used coolant is pumped into the filter where it gravity flows out of the filter into the clean compartment. Excess flow from the clean compartment overflows to the dirty tank where it is refiltered. When the filter pauses to dry and discharge, the dirty tank acts as a buffer and stores coolant. When the filter comes back on line in 11/2 – 2 minutes, the dirty fluid level is lowered and the clean compartment returns to full.

Coolant filter 

 Applications

We have over 50 years experience filtering coolants: oil, water soluble emulsions, and pure synthetics.

 Our application experience includes:

•  Gear grinding
• Creep feed grinding
• Surface grinding
• Slot grinding
• Tungsten carbide grinding
• Honing
• Machining systems
• Piston ring grinding
• Bearings: race, track and ball needle grinding
• ID, OD, centerless grinding
• Driveshaft, crankshaft, connecting rod grinding
• Non-metallic countertops, fiberglass, phenolic resins, ceramics, powdered carbon grinding, sawing, sanding
• Please call our sales department to discuss the flux rates, filter sizing and expected performance for your particular application.

 Sumps

•  Custom Engineered.
• Flat bottom, sloped bottom, cone shaped.
• Circular, rectangular.
• Electrically controlled.
• Pneumatic backups available.
• Interfaces to grinder to: power up/shutoff; alarm; status
• Overflow alarms standard: high level alert to grinder followed by time delayed coolant shutoff
• Can include High Pressure supply pumps to reduce length of plumbing runs with pressurized coolant
• Can integrate with hydraulic cooling using heat exchangers

Ancillary Equipment

These ancillary system components will be fully integrated into the system controls.

•  Chillers: Air cooled, water cooled, remote condensers, submersible coil
• Heat Exchangers using existing chilled water
• Automatic Coolant Makeup- add coolant as required to maintain levels
• Blend neat water soluble coolants with water to desired concentration
• Tramp oil removal systems

The Oberlin Filter delivers ultra clean coolant

Dry Filtered Solids

• Filter cakes over 90% solids by weight in typical steel grinding.
• Discharges a dry cake with less coolant loss.
• Oberlin’s thicker cakes trap far more metal fines then paper alone. Greatly improving the cleanliness of the coolant.

The filtered solids automatically discharge in an extremely dry cake

• High performance media and depth filtration typically delivers less than 10 ppm solids above 10 microns
• Lengthens coolant life 5-10 times
• Filters have flow rates ranging from 15gpm - 2,000gpm
• Optional, cleanable, semi-permanent belts available for certain applications
• Better surface finish
• Less wheel loading/burn
• Better part size control
• Less heat build up
• Less tool wear
• Dress wheels less

Dr. Kalyan Roy, Country Head-India Operation