SPAIN

There is an Auxiliary Conveyor which interrupts the flow of clean fluid and attracts steel fines and also entraps cotton polishing mop floating fines via strong permanent magnets driven by conveyor behind a stainless steel screen. These fines automatically eject into a sludge bin. Two of the three sludger bins are vacuum dried, resulting in easy disposal. These Filters have been running since October 2009, without breakdown. Savings are enormous.

Each of these Filters serves eight grinding machines, four either side of the filter. Volume of coolant is 200L/min. The Control Panel allows the operation of each bank of grinders to run separately. Therefore each operator can stop the coolant floe and make any adjustments without affecting the other bank of grinders. At the end of shift there is a run-on timer allowing the machine to continue to filter for a set period. The Filter will automatically shutdown when the timer expires.


A sample of coolant was taken from each of the first two Filters. These were analysed independently by Swansea Tribology Sevices. The ISO 4406 code was 18/17/15 and 18/17/14 respectively. We have since modified these filters in line with the latest design and believe this coding will improve. These will be published soon.

The concept of the Sludger was to produce a de-oiling machine to handle sludge which was discharged from Pre-coat filter systems. These systems use a powder to increase the filtration capabilities of the filter element. Having installed units manufactured by others we found that the level of cleanliness of the recovered fluid was very poor. This resulted in severe problems pumping the dirty fluid back to the filter and overloading the filter with contaminated fluid. A machine was designed by Malcolm Dendy, a highly experienced filtration engineer. This machine was built in our Essex factory and later installed in a World Class bearing manufacturers facility in UK. During tests, prior to delivery, we recovered 37% oil by weight from the sludge supplied. It must be born in mind that this sludge had settled in the Customers factory and free oil removed before we received it.

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The actual figure of oil recovery, now the machine is on site being directly fed by the discharge of the filter will be much higher. The original oily sludge cannot be disposed by landfill, therefore the producer of this waste product must either store the waste indefinitely or find an alternative. The resultant dry sludge from the Sludger is suitable for incineration, therefore disposal costs are dramatically reduced. The Sludger can therefore operate automatically, designed to operate directly with your filter, recovering valuable oil and producing a dry sludge suitable for disposal. In some manufacturing processes the metal within the sludge can be highly expensive, such as carbides. Customers grinding carbides for tooling wish to recover this expensive material. This can only be done by specialist incineration. This operation cannot be carried out when the sludge is wet. Therefore the Sludger is the first step in the chain to metal recovery. Contact us now to save on oil/coolant recovery and disposal costs.

The vacuum filter is a conveyorised tank with a vacuum septum under. The floor of the tank, separating these two sections, is made of perforated plate. A paper media is then placed over the perforated plate, and held tight to the plate by a flight bar conveyor. The paper media is supplied on a roll, which is supported at the end of the tank. The dirty coolant is discharged into the top section of the tank. The System pumps draw coolant through the media into the vaccum chamber, and then onto the machine tool. A percentage of clean coolant is transferred to a clean tank mounted above the dirty tank. This tank remains full at all times to support a regeneration when required. When the paper media becomes blocked with debris, the vacuum will rise to a set point.  When reached,  the clean coolant stored in the Clean tank will discharge into the vacuum chamber releasing the vacuum. Simultaneously the conveyor will index allowing a certain length of new clean media to enter the filtration area. The system resets after this regeneration period, and the system pumps then begin to build a vacuum again in the vacuum chamber. The spent media is automatically scrapped clean and then rewound onto a mandrel for disposal. The vacuum Filter can be used for single or multiple machine tool installations. The vacuum filter is suitable for a clarity down to 15 micron. However, this figure is only achievable if a cake is built up on the media, which creates a very thick additional filter to the paper media. This is usually found only on grinding processes. Filtration clarity can be down to 8 microns in this instance. Clarity is dependant on the material being machined, and the type of cutting fluid filtered. The paper media also is of paramount  importance,  and can be varied to suit the material and fluid.
Media Free.
Vacuum filters can be produced using a continuous belt, thus saving on disposable paper media. The belt is cleaned automatically and is and endless belt. 

Pre-coat vessel.
A circular vessel with conical base and domed pressure top. The top dome is separated by a tube plate. Filter “Candles” are fitted to the tube plate. These can be made of various designs, but basically a perforated tube, kept in tubular form by an internal spring. These tubes are pre-coated with disposable power media for ultra fine filtration. The cone is fitted with a large discharge valve. When the differential pressure of the filter reaches a predetermined setting the vessel will blow-down. This is accomplished by introducing compressed air into the dome above which forces air through the candles to remove the powder. Simultaneously the dump valve at the base is opened to allow the coolant/oil and sludge to be discharged into the waste conveyor below. The pre-coat process then has to be restarted. The supply of clean fluid to the machines is uninterrupted during this cycle as clean coolant volume in  the clean tank is sufficient for the time of the pre-coat cycle. After the pre-coat cycle is complete the vessel reverts to filter mode, and the dirty coolant passes through the pre-coated candles into the clean tank

Discharged sludge
The discharged sludge is obviously heavily contaminated with oil / coolant. It is therefore very difficult to dispose this sludge to landfill. We therefore recommend the use of a Sludger, to reclaim the oil and render the sludge relatively dry for incineration by a waste disposal company. Savings in oil reclamation and disposal costs are high.

Drum filters can also be used inside drag conveyors. These filters are particularly useful for aluminium swarf as they can handle the floating fines very well.

Each application has to be designed to suit all parameters, including type of chips, material, type of fluid etc.

Filter System for a single CNC machine, comprising a drag conveyor for removing heavy steel swarf, allowing the semi clean coolant to weir over to a chute feeding a gravity filter.