Technical field:

The present invention relates to a device for cleaning fluids such as cutting fluids, washing fluids or other fluids, from e.g. oil leaks, such as lubricants or other impurities.

Background art:

Cutting fluids are used for cooling and lubrication during milling, drilling and other types of machining. During such operations lubricant or the like, and other impurities, often leak into the cutting fluid, gradually contaminating it and making it unusable. A simple and efficient device is sought to allow separation of these impurities from the cutting fluid so that this can be used again, i.e. re-circulated in the machining process. Oils leaking in may be lubricants, hydraulic oils, slide grease, etc. Similar problems often exist for other fluids, such as fluids for washing where it is also desirable to be able to get πd of impurities in a simple manner.

Description of the invention:

The invention aims at a solution to these and other similar problems. It is characterized in that it comprises a float for application in the fluid to be cleaned, e.g. a cutting-fluid vessel, said float consisting of a container with an upper part of a type that will float on inner and outer fluids, e.g. with lower density than these fluids or with the aid of an air pocket, thereby constituting a floating body which floats on the surface fluid entering through an inlet at the top of the container, side walls and a bottom, together forming a container with an inlet at the top and a conduit leading from the container to a pump for pumping off surface fluid that has entered the container. The float thus has an upper part in the form of a floating body which floats on the surface fluid that has entered the container. The float floats on the fluid and the impurities are deposited in a thin layer on top of this, such as oil on top of cutting fluid. When the pump is not in operation the upper part floats at the same level as the surrounding fluid, but when it is in operation the upper part will sink slightly below the surface of the fluid and impurities enter the container through this upper inlet.

In a preferred embodiment the float consists of a bellows and an upper part as described above, the bellows being connected to the bottom. An important advantage with this is that when the contents in the inner container with bellows-like walls decreases, the container is compressed by way of these walls and its upper edge sinks in relation to the surface of the surrounding fluid so that more fluid flows in from the outside. The inflow can be reduced by reducing the pump effect. When the contents in the inner container increases, the inner container expands due to the bellows-like walls. The upper edge then rises in relation to the surrounding fluid, and less fluid enters from the outside. This can be counteracted by increasing the pump effect. A considerable advantage is thus that removal of the surface fluid can be controlled with great accuracy in proportion to the pump effect. At a given flow 1 mm of the surface fluid is removed, and at double that flow the upper part sinks correspondingly, and 2 mm of surface fluid is removed.

In another embodiment the side walls are flexible or inflexible, and movable in relation to a bottom arranged inside the walls, with a space to the side walls in the form of a narrow gap. This enables relative movement between side walls and bottom.

Brief description of the drawings: The invention is described by way of example in the accompanying drawings, in which Figure 1 shows a float in the form of a bellows for application in a vessel containing fluid, such as cutting fluid. Figure 2 shows an alternative embodiment.

Description of embodiment:

Figure 1 shows a float (1) according to the invention, having an upper part (2), either having lower density than the inner and outer fluids (15, 14, respectively), or provided with an air pocket. This upper part floats on fluid (15) which has entered the container when cleaning cutting fluid, for instance. Cutting fluid is used in various machining processes such as milling, drilling, etc. and various oils, such as lubricants, hydraulic oil, slide grease, are also used for these processes.

Other impurities, such as metal shavings, dust, etc., may also result from the machining process and may leak into the cutting fluid together with the lubricant and contaminate it after a while. Such impurities for the most part float on top of the cutting fluid. The upper part of the container floats on the surface fluid (15) that has entered. This upper part (2) may consist of a milled PVC body (2) provided with an inlet (5), or of a metal body with an air pocket. The side walls consist of a bellows (3) made of a suitable rubber mixture and connected between the upper part (2) and a bottom part (4) of stainless steel attached to the bellows (3).

The impurities enter the float/ container and are pumped out via a pump conduit (6, 7) by means of a pump (not shown). The pump conduit consists partly of a pipe (6) protruding into the container (1), its orifice being close to the bottom. The upper part of the pipe continues to a pump (not shown) and the impurities are pumped to a waste container or the like. When the pump is not in operation the upper part (2) floats at the same level as the surrounding fluid (13), but when it is in operation the upper part will sink slightly (see above) and surface fluid and impurities enter the container.

During pumping a varying up and down movement is obtained (see the double arrow), which facilitates draining off.

Figure 2 shows an embodiment with rigid or flexible side walls (8) which are movable in relation to a bottom (9). The bottom (9) fits the walls with a certain clearance (10) and, as in the previous case, an upper part (2) is provided, having a density lower than both the inner and outer fluid. Pumping off is effected via the conduit (6, 7).

The invention may be varied in many ways within the scope of the appended claims.