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 filters 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.
We have over 50 years experience filtering coolants: oil, water soluble emulsions, and pure synthetics. Please call our sales department to discuss the flux rates, filter sizing and expected performance for your particular application.
When applicable, the Oberlin Filter can use a cleanable andreusable belt instead of disposable paper/media belt.Our cleanable belt filters are extremely efficient in saving our customers in consumable costs.
Oberlin Filter Company makes fully automatic coolant filtration systems ranging from 20 gpm to 6,000gpm. These systems are designed to support a single machine like a gear grinder, or an entire shop. The larger, central systems will usually have sumps at each machine to pump back dirty coolant to the dirty tank. The larger systems also tend to have redundant filter pumps and clean pumps to minimize downtime. The Oberlin Filter is simple in design resulting in a reliable uptime availability range of 99%. A large portion of our customer base are repeat customers which speaks for itself in regards to Oberlin's Filter users expecting the performance and reliability of our filtration systems.
In some situations the coolant doesnt 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.
MP Systems has launched a new coolant filtration system designed to prevent chips from accumulating inside a CNC machine tools coolant tank and causing coolant starvation of the machine tools flood pump and the high pressure coolant pump.
Experienced machine tool operators have learned to accept the work stops created by these issues as normal byproducts of the machining process, MP Systems Engineer Brian Jalbert says, but with the Purge they dont have to anymore.
A machine tools coolant tank has two sides: a clean coolant side and a dirty coolant side, Jalbert explains. The dirty side contains a basket that catches larger chips, preventing them from settling on the dirty side of the tank. But this basket allows smaller chips and fines to pass through its walls, where they can settle into the dirty side of the tank. To keep them from flowing into the clean side, theres a screen between the two sides of the tank. However, many of the smaller chips and fines can pass through this screen or get trapped in it and clog it.
Thats when the trouble starts, Jalbert says. These small chips and fines build up in the coolant tank where they consume space, which reduces the coolant volume in the tank. In addition, the clogged screen prevents coolant from flowing into the clean side, which compounds the problem.
When coolant volume drops on the clean side of the tank, the machine tools flood pump cant pump enough coolant through the machine to avoid sucking air. If the machine is running with a high pressure coolant system, that pump will also become coolant starved, which triggers an alarm to shut down. When this happens, the machine tool shuts down.
The Purge prevents these problems, Jalbert says. Its a full-flow system. It pulls coolant from the dirty side of the coolant tank, filters it and returns it to the clean side of the coolant tank faster than the flood and high-pressure coolant pumps draw from it. This prevents coolant starvation of the pumps.
In addition to preventing coolant starvation of the flood and high pressure coolant pumps, the Purge keeps small chips and fines from clogging the machine tools nozzles and lines. By keeping the coolant cleaner, part quality is improved and cutting tool life is extended.
As an added bonus, the machines coolant tank doesnt need to be cleaned nearly as often. Cleaning a coolant tank is a nasty job that nobody wants to do, Jalbert says. Its also time consuming and you have to shut the machine down to do it. If the machine is inside a caged cell, its a task than can take days. If you can eliminate this job even once, the Purge will pay for itself.
The Purge can hold up to 20 gallons of debris. When its full, users simply lift out the filter bags. The cost of the filter bags depends on the desired level of filtration and the type of bag used. A standard 5-micron felt bag costs four dollars.