Contaminants' Sources Affect Coolant Filtration Selection

The selection of the proper coolant filtration system takes in consideration the various parameters which define the operation, fluid and types of contaminants and their respective volumes. The type of contaminants should be evaluated closely. The following is a cursory definition of the sources which will aid in understanding the general impact different types of contaminants could have on a coolant filtration system. There are three general sources of contaminants: direct, indirect, and foreign.

Direct-this is where the contaminants are a direct result of the operation; grinding, machining, etc. These operations create contaminants on purpose or else they would not be working. The ratio of contaminants to fluid is relatively high so the filter would be selected to handle the high solids ratio.

Indirect-contaminants are an indirect result of the operation: wire drawing, rolling, and forming. It is not the intention of the operation to create solids, but it does. Here the ratio of solids to fluid is lower than the direct source. Also, the range of particle sizes is a much narrower so the filter would use a tighter media and would not generate the same kind of cakes found in the direct source.

Foreign-Contaminants in this category are foreign to the operation: tramp oil in waterbase coolants, water in oil coolants, plant debris, and dissolved salts in the waterbase coolant. The amounts involved in this category are usually small, however, some applications can not tolerate even small amounts. The filter must be able to cope with foreign matter either by removing it or surviving it so another device on the system can intercept it. An example is where tramp oil separators work on the same system as the filter.

Coolant filtration systems in general usually have two of these categories. A machining operation can have direct and foreign. Some applications could have all three; such as grinding. A grinding operation can have the swarf as the direct, abrasive grit as the indirect and hydraulic oil leakage as foreign.

Harrigan Solutions has an engineering staff with experience in measuring the impact of the three sources to select and size the proper filter for the operation. The field engineers can also review an existing system which has poor performance to see if it has the proper set-up to address the range of contaminants it is encountering. For more information contact Bill Harrigan at 1-888-685-9603. You can email him at bharrigan@harrigansolutions.com. The website is www.harrigansolutions.com/index.html.