AU462995B2 - Filtration apparatus - Google Patents

Description

47. 1 5 /72 This invention relates to filtration apparatus that is particularly suitable for the filtration of solids from water. For irrigation and other purposes there is a need for large volumes of water having relatively low solids content. In the case of trickle or daily flow irrigation systems for instance water is provided through an outlet as small as about 0.02" diameter for example. As a result solids of a size about 0.02" or larger will block the outlets and regular maintenance is required. Generally the water provided will come from a dam or river or the like and will contain a relatively high solids content. It is the practice to provide filters for removing solids from the water and generally these operate satisfactorily in providing water suitable for trickle or daily flow irrigation purposes. However the filters are necessarily relatively fine and substantial solids content from the water builds up on the filter. The filters are generally placed on the delivery side of the pump and require very frequent cleaning. For cleaning purposes it is generally necessary to discontinue operations to remove the filter r.nd fully clean it. The object of the present invention is to provide a self-cleaning filter that may be used for removal of solids from liquids. The present invention provides a self-cleaning filter including: a filter housing supporting a filtration member through which fluidety-be drawn into said housing whereby to filter said fluid and a fluid outlet for filtered fluid adapted for connection to a pumping means; and, spray

47.105/72 means rotatably supported within said housing and adapted,

as it traverses the inside surface of said filtration

member, to spray cleaning fluid under pressure against the

member whereby to dislodge material collected during

filtration. The invention also provides apparatus for supply

of filtered fluid under pressure including.the aforementioned

self cleaning filter and pumping means connected to the

fluid outlet of the filter and adapted to draw fluid through

the filtration member for supply under pressure at a pump

outlet for the pumping.means.

The following description refers in more detail

to these essential features and further optional features

of the invention. To facilitate understanding of the invention,

reference is made to the accompanying drawings where these

features are illustrated in preferred form. It is to be

understood however, that the essential and optional features

of the invention are not limited to the specific forms of

these features as shown in the drawings. In the drawings:

Figure 1 is a schematic view of the apparatus-

including a preferred self cleaning filter and pumping

means. Figure 2 is an expanded part cross sectional view

of the filter shown in figure 1; and

Figure 3 is a plan view of the filter shown in

figure 2. The self cleaning filter includes a filter housing

for supporting a filtration member shown generally at 6.

The housing may be a substantially cylindrical housing as

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47 01 ;,72 shown in which the filtration member 6 provides a substantially cylindrical wall. Thus the preferred housing includes a substantially circular top wall such as plate 7 and a substantially circular bottom wall such as plate 8. A relatively heavy and corrosive resistant mesh 9 may be provided for support of the filtration member 6. Preferably

the mesh 9 is retained in grooves 11 in the top and bottom plates 7 and 8 as shown best in Figure 2. A seal 12 of any suitable flexible material may be provided for retention of the filtration member 6 against the mesh 9. The top and bottom plates 7/8 may be held together by means of bolts and nuts as shown and a plurality of spacers 13 may be provided in order to limit the extent of pressure exerted on the mesh 9. It will be appreciated that any other suitable construction may be employed as desired. Float means may be provided to maintain the housing afloat in the fluid to be filtered and below the surface of the fluid. Preferably the housing is suspended below the surface of the water to a depth sufficient to avoid the formation of a vortex during the pumping operation as will be further explained below, Preferably the float means are provided by an extension 14 of the top plate 7. Preferably

the float portion 14 is a substantially annular portion as best shown in Figure 3. The filter of the invention includes spray means rotatably supported within the housing and adapted as it traverses the inside surface of the filtration member 6 to spray cleaning fluid under pressure against the member whereby to dislodge material collected during filtration. Preferably the spray includes meansan elongated spray arm 16, the spray means includes an elongated spray arm 16,/wh

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47.105 in b- provided integr_ly with a radially extending support

arm 17 that is rotatably mounted subst antially centrally of the bottom wall 2 of the hous-n-. Preferab.1 the

cleaning fluid is adapted to pass through the supoort arm

to the spray arm. The support and spray arms may be provided

by a pipe or- lflk ms bai as shown best in Figure 2. The

spray means is preferably self-driven by the action of the

cleaning fluid passing therefrom. However the spray means

may be driven by any suitable means, such as by a water

turbine or associated electrical or mechanical motor for example.

The spray arm may be provided with a plurality of

Epray nozzles 18 preferably evenly spaced along its length

end each adapted to provide a fan shaped jet the longitudinal

axis of which is parallel to the axis of the spray arm so that the spray from each nozzle will merge to provide a

continuous longitudinal spray substantially parallel with

the axis of the spray arm. The formation of a suitable

spray is illustrated in Figure 2. In place of nozzles a

number of slots may be provided along the length of the

spray arm and these may be directed in a similar manner to

form a longitudinal spray. Preferably the spray arm is located to extend

laterally across the filtration member 6 and in the preferred

form is preferably substantially vertically arranged.

Preferably the sprays merge at a point corresponding with the location of the filtration member 6.

The plurality of spray nozzles or slots may be

arranged to provide the spray substantially perpendicularly

with the surface of the filtration members 6. However the

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47, 10- /72 sprays may be arranged, at a slight angle thereto as desired to assist with the self driving function of the spray means. slot Alternatively or in addition a separate spray nozzle or 19 may be -o-.ovided directed at an angle to the perpendicular arm so as to provide a force tending to rotate the support 17 and spray arm 16. .Preferably the nozzle 19 is located at one end of the arpray arm as shown in figure 2. Baffle members 21 may be provided around and adjacent the filtration member 6 thereby to direct aroray from the nozzle 19 substantially perpendicularly through the filtration member 6. In addition the baffle members 21 assist in the jet propulsion of the support'arm. 17. The support arm 17 may be coupled in any suitable pipe uianner with a cleaning fluid supply. means such as with 22. Preferably a rotating joint as shown at 23 in Figure 2 is provided. The cleaning fluid supply means will be further exnlained below. Indicator means may be provided in association and with the spray means to indicate when it is rotating iyhen it is stationary. For instance a light rod 23 may be turnstile fixed to the support arm 17 and adapted to rotate a of the 24 and reflector 25 which can be seen above the level fluid from a substantial distance. If necessary recording r-eans or other signalling means may be provided to indicate speed r-nd record movement of the spray means. If desired spray control means may be provided in association with the means to control its rate of rotation as will be appreciated by those skilled in the art. A fluid outlet is provided for filtered fluid. The fluid outlet is adapted for connection to a pumping

4 62.

means. The fluid outlet may include an outlet pipe 26 coupled through an outlet port 27 to a foot valve 28 as show~n in fiogure 2. The foot valve 28 is shoi in its partly opened position. The apparatus for supply of filtered fluid includes a filter preferably as shown in Figures 2 and 3 in which the outlet pipe 26 is coupled to pumping means. Any suitable pump may be employed as desired. For instance a centrifugal pump 30 as shown in Figure 1 may be used. Preferably the centrifugal pump 30 is connected to the outlet pipe by da fle±ible Pipe 31 so that the pump may be located on the bank above the water level for example. A~secondary filter 32 may be provided to remove the small amounts of impurity that might enter the fluid from the pump itself. The fluid from the secondary filter may then .Dauz off to use. However cleaning fluid supply means are nDruferably provided coupled to the outlet of the Pump to transfer portion of the filtered fluid under pressure to t-ae spray means as cleaning fluid. For this purpose a return pipe which is preferably a flexible return pi-pe as shuwn at 33 in Figure 1 is provided to supply cleaning fluid to the 1pipe 22. A venturi means (not shown) may be provided in association with the cleaning fluid supply means whereby to 1r-troduce air into the stream of cleaning fluid. It will be appreciated that this will reduce substantially the wastage of filtered water returned to the water supply through the cleaning action of the filter. Any suitable venturi may be placed in the pipeline whereby pressure of the water flowing therethrough will cause an introduction

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4 7,1 Ci /72 l ai g O in the claigo of air into the fluid. Air as.--L-ts of filtered water the filter ana reduces the rec i-red for th-is nvr.ose. the preferred It will be appreciated th-en that supply to filter may be located in any suitable water surface preferably in a float below the level of the of a vortex. The pump position to avoid the formation pressure within the is then started to reduace the water through the filtration filter housing. This draw s its structure any solid meriber 6 which retains within Filtered water then passes material present in the water. 30 and secondary filter to use. through the pipe 26 to pump at positive pressure passes Pori;ion of the filtered water rotating coupling 23 to through pipe 33 and through the 16. A spray is provided as tupiport arm 17 and spray arm the inside surface of the aforesaid to impinge against solid material retained filtration member 6 to dislodge the water supply. thereon which passes back into the cleaning water In addition to providing spray necessary to rotate the also provides the jet propulsion housing. Thus the spray arm spray arm 16 around within the member to clean it mnoves s lowly around the filtration that this action successively. It will be appreciated whilst in other portions of continues to clean the filter in for filtration. Accordingly tne filter water is sucked a filtration apparatus which the present invention provides during operation thereof. may be cleaned continuously preferably Control valve means may be provided of means to control the extent in the cleaning fluid supply is supplied to the spray and times at which cleaning fluid

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471 05/72 means. Thus the spray means may be operated

intermittently or continuously as desired. The filtration :,ember 6 may be provided by

any suiLtle filtration medium. For J!--tance the fil-

of tration member may be provided by a fine mesh cauze art. stainless steel or nylon weave as is known in the Whilst the invention has been described with it particular reference to the filtration of water, invention will be appreciated that the principles of the Accordingly may be applied to the filtration of any fluid. in its the term fluid as used herein is to be interpreted

broad meaning as given for example in Hackh's Chemical

Dictionary (4th Edition).

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Claims (1)

1. 47 10572 The claims defining the invention are as follows:

   1. A self-cleaning filter including: a filter housing sunnortin" a filtration msenber t-rou-h ,which Aa fluid ma e drawn into said housing whereby to filter said fluid and a fluid outlet for filtered fluid adapted

   for connection to a pumping means; and, spray means rotatably supported within said housing and adapted, as

   it traverses the inside surface of said filtration member, to spray cleaning fluid under pressure against the member

   whereby to dislodge material collected during filtration.

   2. A filter as claimed in claim 1, wherein said housing is a substantially cylindrical housing in which

   caid filtration member provides a substantially cylindrical wall, said spray means including an elongated spray arm

   provided with a plurality of spray nozzles extending across the inside surface of said member.

   3. A filter as claimed in claim 2 including a radially extending support arm rotatably mounted substantially

   centrally of the lower wall of said housing and through

   which cleaning fluid may pass to said spray arm.

   4. A filter as claimed in any preceding claim wherein said spray means is self driven by the action of said. cleaning fluid as it leaves said spray means.

   A filter as claimed in claim 4 wherein a plurality of baffle members are provided adjacent said filtration

   member and wherein one of said spray nozzles is adapted to

   direct cleaning fluid against said baffles whereby to drive

   said spray means. 6. A filter as claimed in any preceding claim including float means whereby to maintain said housing

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   47,105 72 and below the surface afloat in the fluid to be filtered of the fluid. A filtor as claimed in claim 1 substantially 7. as hri ore .e•cribed ;:ith reference to the accomnanying

   drawings. fluid under 8. Apparatus for supply of filtered filter as claimed in pressure including a self-cleaning means connected to said any preceding claim and pumping fluid through said fluid outlet and adapted to draw at a pump filtration member for supply under pressure

   outlet for said pumping means. 8 including a 9. Apparatus as claimed in claim outlet of said cleaning fluid supply means coupled to the filtered fluid under pressure Spunp to transfer portion of the fluid. to said spray means as said cleaning 8 or claim 9, Apparatus as claimed in claim supply of cleaning fluid including venturi means in the the steam of cleaning fluid. whereby to introduce air into Apparatus as claimed in claim 8 substantially 11. reference to the accompanying as hereinbefore described with

   drawings.

   DATfDl: 25th September, 1972

   rKHILLIPS ORMIONDE FITZPATRICK Attorneys for P.OBT LAWR3NCE L ,IS

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