Abstract: The present invention is an automatic filter cleaning system which includes a solvent dewaxing filter which removes wax from a wax mix slurry and provides a filtrate. Status control apparatus is connected to the filter for affecting the operational status of the filter. Drain apparatus responsive to a control signal controls draining of the filter. Cleaning apparatus is also connected to the filter. A control network connected to the status apparatus, the draining apparatus and the cleaning apparatus controls those apparatus in a manner so as to allow selective changing of the status of the filter from an operational state to a down state to automatically drain the filter and clean the filter while the filter is in the down state.

Abstract: A control system controls a lubricating oil dewaxing apparatus. The temperature of waxy oil flowing through the apparatus is controlled. A sequential plurality of temperature sensing means senses the temperature of the waxy oil. A Comparing Means determines an isothermal heat transfer zone corresponding to latent heat transfer wax crystallization. Temperature upstream of the isothermal zone is controlled to a selected chilling rate. Temperature downstream of the isothermal zone is controlled to a selected filtering temperature. The control system effects the growth of wax crystals of a uniform and moderate size for optimum filtering rate and oil content.