Selecting filtration equipment is the combined result of many considerations. In addition to removing undesirable material from a liquid stream, the filtration method selected must also satisfy other requirements. Installed costs must be weighed against operating costs. Waste disposal costs must be considered. Is continuous flow a requirement of the application, or can the filtration equipment be operated intermittently? Is worker exposure to the process liquid during filter cleaning or replacement a problem? These and other factors must be weighed to ensure the right filtration method is implemented for a given application.
Before selecting a filter for a particular application, ask yourself the following questions:
1. What is the quality of filtration required?
2. What are the conditions (flow, pressure, temperature) of the process?
3. Is it a continuous or batch process? How large is the batch volume?
4. What are the material characteristics of the solids being removed? (How large are the particles? Is the material hazardous? Can the material being removed be recycled back into the process stream at another point?)
5. What are the waste disposal costs? How often do bags or cartridges need to be replaced? Can the waste volume be reduced or eliminated by switching to a different filtration method? Disposal costs for used bags and cartridges are about half of the purchase price. And with hazardous liquids, disposal cost can easily exceed the purchase price. When comparing a bag or cartridge filtration system with a self-cleaning system with permanent, fixed media, these disposal costs should be included in the comparison.
6. What are the labor and downtime costs for filter or cartridge replacement? Can downtime be minimized by switching to a different filtration method?
Careful consideration when choosing a liquid filtration system will offer numerous potential benefits. A wise filter selection can minimize process downtime; reduce or eliminate waste disposal costs; limit worker exposure to the process liquid; reduce maintenance time and expense; and improve product quality. Therefore, it is important to review all the available filtration options and identify potential areas where adding or upgrading filtration can provide cost savings.
Chris Rau has 15 years of filtration industry experience, including product development, application engineering and laboratory roles. He now manages the new product development teams for filtration hardware, replaceable filter media, and measurement systems within Eaton’s Filtration division.