Filter

Abstract

The present invention discloses a filter comprising a tube extending from a first end to a second end and having a bore with an internal cross-sectional area. The tube comprises an inlet with an inlet cross-sectional area which is positioned through the first end of the tube. The tube also comprises an outlet with an outlet cross-sectional area, wherein the inlet cross-sectional area is less than the outlet cross-sectional area and so debris small enough to enter the inlet will tend not to block the outlet, which is larger. The filter further comprises a plurality of further inlets, often slots, in the tube between an outside thereof and the bore. In a preferred embodiment, the first end may be tapered and especially dome shaped. This helps to direct debris towards an outside of the tube, where it is less likely to be drawn into the filter and potentially block it or a downstream component, such as a nozzle. The filter may be attached to a pipeline and a nozzle.

What is claimed is: 
     
         1 . A filter comprising:
 a tube extending from a first end to a second end, the tube having a bore with an internal cross-sectional area;   an inlet to the tube, the inlet being positioned through the first end of the tube and the inlet having an inlet cross-sectional area;   an outlet from the tube the outlet having an outlet cross-sectional area;   a plurality of further inlets in the tube between an outside thereof and the bore;   
       wherein the inlet cross-sectional area is less than the outlet cross-sectional area. 
     
     
         2 . A filter according to  claim 1 , wherein the inlet cross-sectional area is less than the internal bore cross-sectional area. 
     
     
         3 . A filter as claimed in any preceding claim, wherein the combination of the inlet and the plurality of further inlets provides a K-factor equivalent or greater than the K-factor of an open tube of the same dimensions as the tube of the filter. 
     
     
         4 . A filter as claimed in any preceding claim, wherein the first end is tapered such that the centre of the first end extends longitudinally further than an outer portion of the first end. 
     
     
         5 . A filter as claimed in any preceding claim, wherein the first end is dome-shaped. 
     
     
         6 . A filter as claimed in any preceding claim, comprising a pipeline mounting means for mounting it to a pipeline. 
     
     
         7 . A filter as claimed in any preceding claim, comprising a nozzle mounting means for mounting a nozzle thereto. 
     
     
         8 . A filter as claimed in any preceding claim, wherein the further inlets comprise slots. 
     
     
         9 . A filter as claimed in any preceding claim, wherein the further inlets extend generally parallel to the longitudinal direction from the first to the second end. 
     
     
         10 . A filter as claimed in any preceding claim, wherein the further inlets extend for up to 75% or up to 50% of the length of the tube. 
     
     
         11 . A filter as claimed in any preceding claim, wherein the further inlets extend for a portion of the tube between the first end and a middle of the tube. 
     
     
         12 . A filter as claimed in any preceding claim, wherein there is at least 4 further inlets, optionally up to 20 or up to 24. 
     
     
         13 . A filter as claimed in any preceding claim, wherein the further inlets have a width of at least 1 mm or optionally, a width of 1-3 mm or 1.5-2.5 mm. 
     
     
         14 . A filter as claimed in any preceding claim, wherein spacing between the further inlets is 50%-150% larger than the width of the slots. 
     
     
         15 . A filter as claimed in any preceding claim, wherein the cross-sectional area of the inlet has a height to width ratio of at most 2:1, optionally at most 1.5:1 or at most 1.1:1. 
     
     
         16 . A filter as claimed in any preceding claim, wherein the internal cross-sectional area of the tube has a height to width ratio of at most 2:1 optionally at most 1.5:1 or at most 1.1:1. 
     
     
         17 . A nozzle apparatus, comprising a filter as claimed in any preceding claim, and a nozzle with a nozzle outlet, the nozzle outlet having a nozzle outlet cross-sectional area. 
     
     
         18 . A nozzle apparatus as claimed in  claim 17 , wherein the inlet cross sectional area is less than the nozzle outlet cross-sectional area. 
     
     
         19 . A nozzle apparatus as claimed in  claim 17  or  claim 18 , wherein the further inlets are of a suitable length where two in combination equals or exceeds the flow required to give the corresponding K-Factor of a nozzle attached to the filter in use. 
     
     
         20 . A pipeline apparatus comprising a filter as claimed in any one of  claims 1  to  16 , attached to a pipeline. 
     
     
         21 . A pipeline apparatus as claimed in  claim 20 , comprising a nozzle. 
     
     
         22 . A pipeline apparatus as claimed in  claim 21 , comprising a reducing bush connecting the nozzle to the pipeline, wherein the length of the tube extends beyond the reducing bush. 
     
     
         23 . A pipeline apparatus as claimed in any one of  claims 20  to  22 , wherein the filter is added to an end of the pipeline, and extends therein, substantially parallel to the main longitudinal axis of the pipeline. 
     
     
         24 . A pipeline apparatus as claimed in any one of  claims 20  to  22 , wherein the filter is added to the pipeline, and extends therein, substantially at a right angle to the main longitudinal axis of the pipeline. 
     
     
         25 . A pipeline apparatus as claimed in  claim 24 , wherein the first end extends into the central 10% of the pipeline. 
     
     
         26 . A pipeline apparatus as claimed in  claim 24 , wherein the first end extends into the central 3-4% of the pipeline. 
     
     
         27 . A nozzle apparatus, comprising:
 a filter comprising a tube extending from a first end to a second end, the tube having a bore with an internal cross-sectional area;   an inlet to the tube, the inlet being positioned through the first end of the tube and the inlet having a first inlet cross-sectional area;   an outlet from the tube the outlet having an outlet cross-sectional area;   a plurality of further inlets in the tube between an outside thereof and the bore;   a nozzle with a nozzle outlet, the nozzle outlet having a nozzle outlet cross-sectional area;   wherein the inlet cross-sectional area of the filter is smaller than the outlet cross-sectional area of the nozzle.   
     
     
         28 . Use of a filter as claimed in any one of  claims 1  to  16 , with a nozzle. 
     
     
         29 . Use of a filter as claimed in any one of  claims 1  to  16 , with a sprinkler system for firefighting/fire containment. 
     
     
         30 . Use of a filter as claimed in any one of  claims 1  to  16 , with a burner head for hydrocarbons. 
     
     
         31 . Use of a filter as claimed in any one of  claims 1  to  16 , in a pipeline.