Abstract
The invention relates to a filter device comprising an inlet chamber, an outlet chamber, a filter system which separates the inlet chamber and the outlet chamber. The filter device is characterised in that the inlet chamber comprises at least one liquid supply line and at least one liquid discharge line and the outlet chamber does not comprise a liquid supply and comprises at least one liquid discharge line. The invention also relates to a corresponding filter method.
Claims
1. A filter device for filtering a liquid, comprising: an inlet chamber for receiving a liquid to be filtered; an outlet chamber including at least one liquid discharge line and does not have a liquid supply line; a filter system at the bottom of the inlet chamber, which separates the inlet chamber and outlet chamber; a liquid supply line situated centrally above the filter system for introducing liquid to be filtered into a center of the inlet chamber; a liquid discharge line in fluid communication with said inlet chamber for discharging a portion of liquid received in said inlet chamber from said inlet chamber without passing through said filter system; spiral flow elements increasing in height as they extend from said center of the inlet chamber are positioned above the filter system, and control the flow of the liquid to be filtered so that it does not flow directly to the liquid discharge line; wherein liquid to be filtered is flowed into the inlet chamber at said center where it encounters said spiral flow elements, with some liquid passing through said filter system as it flows outwardly through said spiral flow elements, and some of the liquid being discharged, unfiltered, through said discharge line.
2. A filter device for filtering a liquid as recited in claim 1 wherein said filter system comprises a filtration medium supported by a plate having holes extending therethrough.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Examples of preferred embodiments of the filter device according to the invention are illustrated in the drawings.
(2) FIG. 1 shows schematically a preferred embodiment;
(3) FIG. 2 shows schematically a further preferred embodiment;
(4) FIG. 3 shows schematically a third preferred embodiment;
(5) FIG. 4 shows schematically a preferred filter in spiral form from above;
(6) FIG. 5 shows schematically the filter in spiral form in side view;
(7) FIG. 6 shows schematically a preferred filter;
(8) FIG. 7 shows schematically a further preferred filter;
(9) FIG. 8 shows a preferred embodiment as a belt filter in side view; and
(10) FIG. 9 illustrates a preferred embodiment in perspective view.
(11) FIG. 10 illustrates a preferred embodiment from above.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
(12) FIG. 1 shows a preferred embodiment, which enables a very simple yet effective implementation of the invention. A filter system 4 is arranged in a pipe so that it covers an outlet area 2 separated in the pipe. The pipe area in front of the filter system can be seen as an inlet area 1 and a further separate area of the pipe behind the filter system, which is not closed by the filter, is the liquid discharge line 3 assigned to the inlet area. The filter system 4 is arranged to be inclined in the pipe and comprises an upper screen and a lower screen support plate.
(13) FIG. 2 shows a further preferred embodiment, in which the filter system 4 has the form of a spiral. In the shown case the outlet area 2 is located on one side of the filter system and the inlet area 1 is located on the other side. There are two liquid discharge lines to the right and left of the center. The liquid discharge line 3 assigned to the inlet area is shown on the left and a portion of the liquid discharge line assigned to the outlet area 2 is shown on the right. When fluid flows through the pipe indicated on the right, which forms the liquid supply line, into the inlet chamber 1, the fluid flows along the filter system 4 and off to the center in the form of a spiral. Meanwhile fluid passes through the filter due to gravity and flows filtered through the outlet area, at the end of which it can flow off through the relevant liquid discharge line.
(14) FIGS. 3 and 4 shows a further preferred embodiment of a device according to the invention, wherein FIG. 3 shows the device in plan view and FIG. 4 shows the device from the side as a cross-section through the horizontal, central axis of FIG. 3.
(15) The flow elements 7 are arranged in the form of at least one spiral. From the liquid supply line, which is preferably arranged centrally above the filter system, the fluid flows into the inlet area 1 and is forced via the filter system 4 in a spiral-shaped flow direction, in particular from the outside in or from the inside out, so that it flows via the filter system 4, in particular over 90% of the path from the fluid inlet 1 to the liquid discharge line of the inlet chamber. At the end of its path, also preferably at the center or edge of the spiral, at least one fluid outlet 3 is arranged in order to remove the remaining fluid out of the inlet chamber in which dirt particles have become concentrated. Any media can be used as filters which are made from a base material which is provided with openings. The filtration media may be a filter belt supported by a plate 9 provided with openings.
(16) The fluid to be filtered flows through a central inlet area and moves firstly in the area marked by dashed lines (cf. FIG. 3) radially outwards, whilst a portion of it already passes through the filter 4 (cf. FIG. 4) arranged below the inlet area and the complete spiral shape in FIG. 3 into the outlet area. A spiral form (dotted area in FIG. 3) causes the fluid to make a spiral movement, wherein radial widening outwards is still possible at first, but is more difficult with an increasing radius (cf. wedge-like intermediate space below the spiral chambers in FIG. 4) and is finally no longer possible. The portion of fluid, which is not forced through the filter 4, is guided through channels to the fluid outlet 3.
(17) FIG. 5 shows a further preferred embodiment, in which the filter system 4 has the form of a swirl or spiral. In the shown case the outlet area is located below the filters and is not visible. The filters do not extend in the shown case up to the upper edge of the chamber which forms the inlet area 1 but run onto its base. The liquid discharge line 3 assigned to the inlet area is located in the center. If fluid now flows through the pipe indicated on the right at the top, which forms the liquid supply line, into the inlet chamber 1, the fluid will flow via the filter of the filter system 4 and to the center in the form of a spiral. In the meantime it is guided by the form of the filter system and a portion of the fluid passes at the same time through the filter system 4 and flows off filtered.
(18) FIGS. 6 and 7 show two advantageous filters. The arrow above the Figures indicates the flow direction of the fluid. The inlet area is above the filter is and the outlet area is below the filter.
(19) In FIG. 6 the filter has oblique holes, which are inclined against the flow of fluid. The fluid is thus not pushed by the following fluid through the holes but on its path through the filter has to perform a change in direction of more than 90 relative to its flow direction.
(20) In FIG. 7 the filter has the form of a sawtooth, wherein the holes are arranged respectively on the sides facing away from the fluid flow. Here too the fluid flowing over the filter on its way through the filter has to change direction by more than 90 relative to its flow direction.
(21) Both filter forms are used in particular so that gel-like impurities are not pushed through the filter but even if they do enter one of the holes they are carried off again by the fluid flowing past.
(22) FIG. 8 shows schematically a preferred embodiment of a belt filter according to the invention in side view, in which the inflow 5 and outflow 6 are arranged on the sides of the filter 4 in the form of a filter belt. A melt can pass from the side into the inner chamber through the inflow 5, shown in cross-section (from the direction of the observer or from below the sheet plane) through the filter 4 in the form of a filter belt and can flow back out of the outflow 6 (in the direction of the observer or downwards to the sheet plane). The filter belt is in turn arranged so that the melt, in order to pass from the inflow 5 to the outflow 6, has to flow through the filter belt and cannot flow past the filter belt on a different path.
(23) It can be seen clearly that the inflow 5 and the liquid discharge line, even if they are intended to project laterally slightly over the filter, are arranged at least in an edge area of the filter according to the diameter of the inflow 5 relative to the position of the inflow 5 and the diameter of the liquid discharge line relative to the position of the liquid discharge line.
(24) In the inlet area of the inner chamber a primary melt outflow is shown (the liquid discharge line 3 assigned to the inlet area) through which the polluted melt can be removed from the inlet area.
(25) FIG. 9 shows in perspective a possible positioning of the inflow 5, outflow 6 and primary melt outflow (the liquid discharge line 3 assigned to the inlet area), which preferably still cooperates with a discharge unit which is not shown here. The inflow 5 is located here on the side not facing the observer, the outflow 6 on the side facing the observer and the primary melt outflow (the liquid discharge line 3 facing the inlet area) on the side facing away from the observer (but can also be arranged on the side facing the observer).
(26) FIG. 10 shows a preferred embodiment, a variation of the preceding one, from above. In the latter the primary melt outflow (the liquid discharge line 3 assigned to the inlet area) is provided with a conveying screw as a discharge unit, wherein said screw extends over the whole width of the filter belt and can move impurities over the whole width into the outflow 6 of the discharge unit (into the liquid discharge line 3 assigned to the inlet area). Here the inflow 5 is located on the side of the inner chamber (the delimitations of which are not shown here) and the outflow 6 is located underneath the filter belt, which is indicated by the dashed lines.
