Hoffmann PreCoat Filter

Hoffmann Fully Automatic PreCoat system

For the Finest Surface Precisions for Components machined from Cast Iron, Hard Metal and HSS where Super-Clean Cooling Lubricant is most essential, the Hoffmann PreCoat Filter outperforms every conceivable filter system. Hoffmann PreCoat Filter is the product of choice for Ultra-Fine and Super-Clean Oils, Synthetic Solutions, Process Water and other Fluids where Clarity down to 3µ (nominal) can be achieved. Hoffmann PreCoat Filters are customized as a Standalone Filter or as a Large Central System as required.

Further, the Hoffmann PreCoat Filters come in 3 Customized Versions

• Manual
• Semi-Automatic
• Fully Automatic

1. Soiled coolant tank

2. Filter pressure pump

3. Precoat filter vessel

4. Clean coolant tank

Filter Plates are the basic Support Filter Media of the Hoffmann PreCoat Filter.

Initially, a Fine-Layer of Filter Aid (Diatomaceous Earth, Cellulose, etc.) is allowed to be formed onto the Filter Plates so that the Preformed Fine-Layer acts as the Fine Filter Media and hence the process is called Pre-Coating and the Filter Unit is called as the PreCoat Filter.

Return Coolant from the Machine Tool laden with Dirt is first transferred into the Lift Tank of the Hoffmann PreCoat Filter. A Filter Pump Pressure Feeds the Soiled Cooling Lubricant into the PreCoat Filter Vessel to force it through the Precoated Filter Plates where the Metal Fines and other Dirt is arrested by the PreCoated Fine-Layer to deliver a Clean Fluid into the Clean Coolant Tank.  The Super-Clean Cooling Lubricant may then be Cooled in the tank before being pumped back to the Machine Tool.

With the ongoing process, the Filter-cake grows and gets compressed steadily resulting in gradual drop in Throughput and corresponding increase in Pressure-Drop in the Filter Vessel. When a Maximum Differential-Pressure is reached or a Preset Filtration Time expires, the Process of Filtration stops and the Filter Plates are then ready for Cleaning & Regeneration.

The Filter Plates are cleaned to discharge the Filter Sludge which is then dried for disposal.

Depending on the Degree of Automation, the Dosing of Filter-Aid, Cleaning of the Filter Plates and Drying of the Filter Sludge can be either Manual, Semi-Automatic or Fully-automatic.