The invention relates to a method by filtration of coolant.

Further the invention relates to a filtration system to filtration of coarse and smaller particles in a coolant, where the coarse and the smaller particles are obtained by a processing in a CNC machine, where the filtration system is connected to a sump with a conveyer to which coarse and smaller particles from the processing in the CNC machine are lead.

US 8,211,304 B1 discloses a coolant filtration system where a drum filter separate coarse particles from the coolant to, via a conveyer, to a chip receptacle. The smaller particles are lead to a fine filter.

It is now a purpose with the invention to provide a coolant filtration system with fewer components in the filtration process.

The purpose is fulfilled with a method defined in the introductory part of claim 1 , that is characterized in that a) The coolant with particles is lead from the CNC machine to a sump with a thereto connected conveyer, said conveyor has at its surface a filter, such that smaller particles are lead through the filter to the sump, whereas the coarse particles are lead on the conveyer to a receptacle

b) From the sump the particles are lead to a pipe in the sump in which a suction process leads the smaller particles to a filtration where the smaller particles are collected and filtrated after which the filtrated coolant, via a tank, are fed back to the CNC machine

c) The steps a) to b) is repeated in a cyclic process.

In this way the coarse and the smaller particles are separated in the same component and ready for further processing in the filtering process.

Expedient embodiments for the method are defined in claim 2 and 3, As mentioned tha invention also relates to a filtration system.

This filtration system is, as defined in claim 4, characterized in that the conveyer on its surface have a filter, in which coarse particles are separated from smaller particles, such that the smaller particles, via a suction process, to the sump connected pipe, are lead back into the filtration system.

In order to increase the efficiency of the filtration system it is advantageous, if as stated in claim 5, that the filtration system is formed as an independent unit, being connectable to the CNC machine or as stated in claim 6, that the filtration unit is form as a trolley cart.

The invention will now be explained in connection with tha drawing on which

Fig. 1 illustrates a known filtration unit,

Fig. 2 illustrates a filtration unit according to the invention,

Fig. 3 illustrates the filtration unit according to the invention with an added feature, whereas

Fig. 4 illustrates a conveyer with a separating facility according to the invention.

On fig. 1, 1 denotes a chamber, in which a metal processing machine, a so- called CNC machine, being able to drill, milling or the like, as it is known.

During operation of such CNC machines it is necessary, to lead coolant, such that unwanted high temperatures are avoided.

As it can be seen a pipe denoted 6, is leading coolant into the CNC machine. During operation in the CMC machine the coolant is mixed with washings.

The coolant with washings can be transported, via a pipe 2, to a chamber 3 that is connected to a conveyer 7 on which washings 8 can be transported into a container 9. As it further can be seen there is to the chamber 3 connected a chamber 5, where the two chambers are separated by a filter 4, such that no washings can be returned into the CNC machine.

10, (fig. 2) denotes a filtering system in its entirety.

With 17, 18 is designated a chamber having an upper chamber 18 and a lower chamber 17. The lower chamber is, via a curved pipe 10 and a container 15 connected with a pipe 14, said pipe leading to a filtration unit, see later, in connection with fig. 4. The upper chamber 18 is with a pipe 19 connected to a vessel 11, said vessel, via a pipe 12 is connected to another vessel 13, said vessel is connected to a low-pressure pump 21, being able to pump coolant into the CNC machine, via a pipe 20. 22 designates a pump, that via a valve 23 and a pipe 23 and a pipe 24 is connected to the upper chamber 18, which functioning is explained below.

The low pressure pump 21 leads coolant into the pipe 20, that is pumped from the vessel 13, said chamber receives the coolant from the chamber 11 that receives coolant, via the pipe 12, that in turn receives clean coolant from the upper chamber 18, since coolant is cleaned by a filter cartridge (not shown) in the pipe 17, 18, since the lover chamber contains washings, that is detained in the lower chamber 17 by the filter cartridge in the pipe 17, 18.

The coolant, that is lead into the pipe 20 is returned in the pipe 14 by a suction process, but now the coolant contains washings that is lead into the vessel 25 and into the lower chamber 17, via the pipe 15.

In this way an automatic cyclic process is provided, where coolant and coolant with washings are circulated in a closed system.

As washings in the pipe 17, 18 are detained, the filter sometimes shall be cleaned. To do that a pump 22 is arranged, that via a valve 23 and a pipe 24 can pump the coolant back through the pipe 16, the vessel 15 and through a pipe 25, said pipe is lead to a drain filter (not shown). On fig. 3 is shown the filtration unit on fig. 2, but now with an electronic box 26. That electronic box is arranged to control a pump such that coolant is kept under a wanted pressure that can lead coolant into the CNC machine.

By the way the electronic box is for the sake of clarity, left out on fig. 2. On fig.4 the pipe 14 is again seen.

As it further can be seen, the pipe 15 is placed under the conveyer. The conveyer is so constructed that it has a built-in filter function in form of a filter on the surface of the conveyer. Washings 28 having a certain size is passing up the conveyer with the surface and filter and from there into a waste tray.

The smaller washings are lead through the filter on the surface of the conveyer and is afterwards sucked into the pipe shown at 29.

Finally, it shall be noted, that the filtration unit van be formed ads a trolley cart with wheels, such that the filtration unit can be removed from one CNC machine to another one.

In that connection, the pipes can be formed as flexible pipes.