Recycling of metalworking fluids

A process for the recycling of used and contaminated metalworking fluids, both oil-based and water-based, said process employing a mobile recycling equipment capable of being moved into close proximity to the sources of said fluids, said equipment comprising the following elements:

• (a) pumping means able to accomodate either a predominately water-based or a predominately oil-based fluid stream for pumping the contaminated fluids from storage sites through appropriate piping and valving means:
• (b) solid separation means selected from hydrocylones and filters of appropriate capacities for eliminating excess solid loadings from the contaminated fluids;
• (c) sterilization means selected from flash pasteurizers and irradiation devices inserted at an advantageous point in the piping means for destroying microorganisms within the contaminated fluids;
• (d) centrifugal means selected from manually cleaned and self-cleaning high speed disk bowl centrifuges, said centrifugal means including a multiplicity of differently sized ring dams for adjusting a separation line within the centrifuge to accommodate the different concentrations of oil and water which may exist within contaminated fluids, said centrifugal means being used for separating contaminated fluids into an oil stream, an aqueous stream, and a solid residue, said pumping means solid separation means, sterilization means and centrifugal means being fluidly interconnected;
• (e) mobile means for transporting said equipment from one site to another;
• said process comprising:
• positioning the mobile equipment in proximity to the contaminated metalworking fluid storage sites;
• pumping the contaminated metalworking fluid from the storage sites to the solid separation means;
• removing metal fines and suspended solids from said metalworking fluid in said separation means;
• subjecting the solid depleted metalworking fluid to said sterilization means;
• passing the sterilized metalworking fluid to the centrifugal means thereby recovering a recycled metalworking fluid.