FIELD OF THE INVENTION

The present invention relates to liquid filtration systems, and more particularly to a waste liquid filtration system that allows viscous and macroparticulate matter clogging the filter to be dislodged and that spaces the filter housing away from the ground surface on which it rests to enhance the sanitary conditions in which the liquid filtration system operates.

BACKGROUND OF THE INVENTION

Waste water filtration is a very important and well documented challenge for the 21 ^st century.

In restaurants and other small business where water consumption is high, water is used at a sink, for example to wash dishes and other articles, before being discharged into the sewer system through drain pipes. The waste water that drains away into the sewer system is frequently filled with grease and other viscous and macroparticulate matter that can be captured at the source if the waste water was being suitably filtered. This is not only true for restaurants and businesses, but also for domestic water consumption. Polluted waste water can be filtered at the sink drain pipe to prevent the waste water from overly polluting the municipal waste water sewer systems. Although some solutions exist such as so-called grease traps that are used for restaurants, these are both ineffective and expensive in addition to requiring third party interventions at regular intervals to empty the grease trap.

One solution that has been proposed to filter waste water at the source of waste water sink discharge is described in Canadian patent No. 2,178,270 entitled Waste Water Grease Filter - inventor C. Cini. This patent shows a filtration system adapted to be connected to a waste water pipe such as a waste water drain pipe under a kitchen sink. It is particularly adapted for small businesses such as restaurants or for domestic use. The filtration system comprises a housing having a waste water inlet, a filtered water outlet and a filter interposed between the inlet and the outlet. The filter is an expandable bag that receives the waste water and retains most greases and macroparticulate matter. When the bag is full, it can be removed and a new filter may be installed.

One problem with the filtration system of Canadian patent No. 2,178,270 is that cold water flowing through the filter will act to congeal the grease and increase the viscosity of the grease and oil and other viscous matter in the filter. The congealed grease and other viscous and macroparticulate matter will clog the filter pores. This results in water not being exhausted as it should, instead filling the bag and possibly overflowing at the sink drain pipe. This also results in the filter bag being replaced prematurely: it is in fact not filled with grease and macroparticulate matter, it is only clogged with both and inflated by water that is prevented from flowing through the filter when it is replaced since the user sees the replacement of the filter as the solution to avoid the waste water drain pipe overflowing. A more efficient use of the filter bag would be for it to be actually more significantly filled with grease and macroparticulate matter before it is replaced.

Another problem with the filtration system of Canadian patent No. 2,178,270 is the concave shape of the rigid water-permeable cradle that supports the expandable filter spacedly over the housing bottom wall. Indeed, by providing a concave cradle, the elastic deformation of the filter as it expands is not maximised, it is instead limited to expanding into the shape of the cradle.

Yet another problem that relates to the filtration system of Canadian patent No. 2,178,270 is that the bottom wall of the filtration system housing rests directly on the ground surface supporting it. This ground surface is often located directly underneath a sink drain pipe and may be wet. Having no space between the bottom wall of the filtration system housing and the ground surface is problematic in that it prevents cleaning of this area and allows water to remain stagnant there, possibly leading to unsanitary conditions. Sanitary inspectors, such as municipal inspectors, are often reluctant to allow any type of flat-walled portion of a device from resting directly on the ground for this reason. Yet another problem with the filtration system of Canadian patent No. 2,178,270 is that it requires piping to adapt to it since its height is not adjustable. To install the device under a kitchen sink, for example, requires that piping of proper length be used to connect the device to both the kitchen sink drain pipe and the waste water outlet pipe.

SUMMARY OF THE INVENTION The present invention relates to a liquid filtration system comprising:

a housing;

a waste liquid inlet in said housing;

a filtered liquid outlet in said housing;

a filter carried by said housing and interposed between said waste liquid inlet and said filtered liquid outlet in such a way that liquid flowing in said housing between said waste liquid inlet and said filtered liquid outlet will pass through said filter for said filter to retain viscous and macroparticulate matter; and

an agitator mounted to said housing and capable of agitating said filter for dislodging viscous and macroparticulate matter that clogs pores of said filter.

In one embodiment, said agitator comprises an arm member movably mounted to said housing and capable of agitating said filter.

In one embodiment, said arm member extends through said housing and defines a manually operable first end protruding outside said housing and a second end located inside said housing, with said arm member being movable between first and second limit positions relative to said housing, with said arm member second end agitating said filter at least in said second limit position of said arm member.

In one embodiment, said arm member second end is equipped with a paddle.

In one embodiment, the liquid filtrations system further comprises a biasing member continuously biasing said arm member towards said first limit position, wherein said arm member may be forced towards said second limit position against the bias of said biasing member.

In one embodiment, said biasing member is a coil spring linked to said arm member and to said housing.

In one embodiment, said filter has the shape of a bag and is connected to said waste liquid inlet.

In one embodiment, said filter is removable for replacing said filter when it is at least partly full of viscous and macroparticulate matter.

In one embodiment, the liquid filtration system further comprises a permeable rigid support seat carried within said housing, capable of supporting at least part of said filter away from a peripheral wall of said housing when said filter is partly filled with viscous and macroparticulate matter and capable of allowing liquid to pass through said support seat towards said filtered liquid outlet.

In one embodiment, said support seat comprises a strainer to which spacers are fixed for spacing said strainer from said peripheral wall of said housing on which said spacers rest, with filtered liquid being allowed to pass through said strainer towards said filtered liquid outlet.

In one embodiment, said strainer is positioned so as to allow filtered liquid to flow towards said filtered liquid outlet both directly without passing through said strainer and through said strainer.

In one embodiment, said housing comprises a hatch allowing access into said housing for removing and replacing said filter.

The present invention also relates to a liquid filtration system comprising:

a housing;

a waste liquid inlet in said housing;

a filtered liquid outlet in said housing;

a filter carried by said housing and interposed between said waste liquid inlet and said filtered liquid outlet in such a way that liquid flowing in said housing between said waste liquid inlet and said filtered liquid outlet will pass through said filter for said filter to retain viscous and macroparticulate matter; and a support member fixed to said housing for spacing said housing away from a ground surface on which said housing would rest.

In one embodiment, said support member is adjustable to allow its relative position with respect to said housing to be adjusted, for adjusting the height of said housing relative to the ground surface.

In one embodiment, said support member comprises a number of support feet each covered with a protective sleeve that is attached to one of said support feet and said housing.

DESCRIPTION OF THE DRAWINGS

In the annexed drawings :

Figure 1 is a perspective view from the front, the top and the left- hand side of the liquid filtration system of the present invention;

Figure 2 is a perspective view from the front, the top and the right- hand side of the liquid filtration system of the present invention;

Figure 3 is a partly fragmented perspective view from the rear and the right-hand side of the liquid filtration system of the present invention, with the housing second side wall and rear wall being partly broken to show the inner elements of the liquid filtration system;

Figure 4 is similar to figure 3, but with the perspective view being taken from the front, the top and the right-hand side of the liquid filtration system;

Figures 5 and 6 are partly fragmented front elevations of the liquid filtration system sequentially showing the arm member in its first position away from the filter and its second position wherein it agitates the filter; and

Figure 7 is an exploded perspective view from the front, the top and the right-hand side of the housing and support feet of the liquid filtration system. DETAILED DESCRIPTION OF THE EMBODIMENTS

Figures 1-4 show a liquid filtration system 20 according to the present invention for use in filtering waste liquid such as waste water that is discharged at a sink drain pipe or the like. Liquid filtration system 20 comprises a housing 22 that defines a peripheral wall including top and bottom walls 24, 26, first and second side walls 28, 30 and front and rear walls 32, 34. Housing 22 is unitary and as such reference to top, bottom, side, front or rear walls only exists in the present specification to facilitate the relative location of the different elements and structures that compose liquid filtration system 20. In any event, the exact shape of housing 22 could vary and it is understood that the shape and configuration shown in the annexed drawings is only exemplary.

Housing 22 is provided with a waste liquid inlet 36 at its top wall 24 for allowing waste liquid to flow into housing 22. Waste liquid inlet 36 comprises an opening that is provided with a waste liquid inlet pipe 38 that may be suitably connected to a waste liquid source, such as a sink drain pipe (not shown) or the like.

Housing 22 is also provided with a filtered liquid outlet 40 on its rear wall 34 adjacent to bottom wall 26 for allowing filtered liquid to flow out of housing 22. Filtered liquid outlet 40 comprises an opening that is provided with a filtered liquid outlet pipe 42 that may be suitably connected to a waste water outlet pipe (not shown), for example one that links to a municipal sewer system.

A filter 44 is carried within housing 22 and is more particularly removably connected to waste liquid inlet 36 by means of a threaded ring 46 that threadingly engages a correspondingly threaded ring 48 fixed to housing 22 around waster water inlet 36. Filter 44 has the shape of a bag and is porous to retain viscous and macroparticulate matter while allowing liquid such as water to permeate and flow through it. The size of the pores in filter 44 will be determined by someone skilled in the art according to the desired filtration capacity of filter 44. Herein, viscous waste or viscous matter is defined as any thick or sticky element including greases and oils, while macroparticulate matter is defined as any particulate matter that can be seen with the naked eye. Although filter 44 is destined to retain at least viscous and macroparticulate matter, it could probably be adapted as desired for retaining some microparticulate matter also that is not visible with the naked eye. So although it is mentioned that filter 44 can retain viscous and macroparticulate matter, this does not mean that it could not retain additional matter also including microparticulate matter. Furthermore, any statement that filter 44 is capable of retaining viscous and macroparticulate matter does not mean that filter 44 is capable of retaining all viscous and macroparticulate matter, but rather some viscous and macroparticulate matter. The size of the pores in filter 44 will be determined depending on the type of liquid being filtered and the type of viscous and macroparticulate matter that would be desirably retained by filter 44. One particular application of the present invention is for use in filtering waste water at kitchen sinks and the like, and consequently a water-permeable filter 44 that retains viscous and macroparticulate matter that is usually found in kitchen drain pipes is envisioned.

By being thus connected to waste liquid inlet 36, filter 44 is consequently interposed between waste liquid inlet 36 and filtered liquid outlet 40 in such a way that liquid flowing into housing 22 between waste liquid inlet 36 and filtered liquid outlet 40 will pass through filter 44 for filter 44 to retain viscous and macroparticulate matter.

Filter 44 is removable for replacing filter 44 when it is partly or completely full of viscous and macroparticulate matter. More particularly, by unscrewing ring 46 from ring 48, filter 44 may be removed from housing 22 through a hatch 50 that includes an opening 52 in housing front wall 32 and a cover 54 that can be removably threadingly installed on housing 22 around opening 52. A new filter 44 may be installed in housing 22 first by being inserted through hatch 50 and then by threading its ring 46 to the housing ring 48.

Filter 44 is preferably elastic so as to expand as it is gradually filled with viscous and macroparticulate matter.

Liquid filtration system 20 further comprises a flat, permeable, rigid support seat 56 carried within housing 22 and capable of supporting at least part of filter 44 when filter 44 is partly filled with viscous and macroparticulate matter. Support seat 56 comprises first and second flat strainer portions 58, 60 each supported by spacers 62, 64 that rest on the housing bottom wall 26. Strainer portions 58, 60 collectively form a strainer on which filter 44 will rest as it is gradually filled with viscous and macroparticulate matter. Permeable support seat 56 is desirable since it prevents filter 44 from resting directly on housing bottom wall 26 which would prevent liquid from passing through the entire section of filter 44 that contacts bottom wall 26 thus rendering this section of filter 44 useless. As seen particularly in figure 3, spacers 62, 64 space strainer portions 58, 60 away from housing bottom wall 26 so that strainer portions 58, 60 are positioned approximately at mid-height of the filtered liquid outlet 40. This allows filtered liquid that flows underneath strainer portions 58, 60 to easily flow out through the lower part of filtered liquid outlet 40 and simultaneously allows filtered liquid that flows over strainer portions 58, 60 to also easily flow out through the upper part of filtered liquid outlet 40. While liquid will normally readily flow over strainer portions 58, 60 through the upper part of outlet 40, the upper part of outlet 40 could occasionally be blocked by the inflated filter 44 itself; in such a case, the filtered liquid would still be allowed to flow out through the lower portion of outlet 40 underneath strainer portions 58, 60. Strainer portions 58, 60 consequently also have the purpose of preventing filter 44 from blocking filtered liquid outlet 40.

It is noted that having strainer portions 58, 60 be flat is an advantageous feature of the present invention. Indeed, if an elastic, expandable filter 44 is used, it will be allowed to expand over the flat strainer portions 58, 60 without being limited in its expansion as was the case with the concave cradle of the prior art device discussed in the Background of the Invention section of the present specification.

According to the present invention, liquid filtration system 20 comprises an agitator 66 mounted to housing 22 and capable of agitating or inducing vibrations in filter 44 for dislodging viscous and macroparticulate matter that clogs pores of filter 44. More particularly, agitator 66 comprises an arm member 68 movably mounted to housing 22 and capable of impacting and agitating filter 44 for inducing vibrations therein. Arm member 68 extends through the top wall 24 of housing 22 and defines a manually operable first end 70 protruding outside housing 22 and equipped with a handle 72; and a second end 74 located inside housing 22 and equipped with a paddle 76.

As suggested in figures 5 and 6, arm member 68 is movable in translation between first and second limit positions relative to said housing, with arm member second end 74 agitating filter 44 at least in the second limit position of arm member 68, as will be detailed hereinafter.

Liquid filtration system 20 further comprises a biasing member in the form of a coil spring 78 linked to arm member 68 and to housing 22. Coil spring 78 continuously biases arm member 68 towards its second limit position.

Arm member 68 may also be moved in rotation around an axis extending through arm member 68 to adjust the position of the curved paddle 76 as desired. The position of paddle 76 may be visually assessed by a user by looking through hatch 50 and its transparent cover 54.

In use, in the first limit position of arm member 68, paddle 76 is located near housing top wall 24 within housing 22, and although it may be in contact with filter 44, it is preferably spaced away from filter 44 at that point. Arm member 68 may be forced towards its second limit position against the bias of coil spring 78 by manually pushing on handle 72. This will force paddle 76 inwardly within housing 22 until paddle 76 impacts with filter 44. In the case where paddle 76 is spaced from (not in contact with) filter 44 when arm member 68 is in its first limit position, pushing arm member 68 towards its second limit position will agitate or induce vibrations in filter 44 upon paddle 76 impacting and then agitating filter 44. In the case where filter 44 is inflated and paddle 76 is already in contact with filter 44 when arm member 68 is in its first limit position, pushing arm member 68 towards its second limit position will still induce vibrations in filter 44 as it is agitated by paddle 76.

As noted above, the vibrations induced in filter 44 by arm member 68 will have the effect of dislodging viscous and macroparticulate matter that clogs pores of filter 44. Indeed, having a filter with suitably small pores to increase its effectiveness at entrapping grease and other small particulate matter has the disadvantage that its pores might become gradually clogged. Grease and other viscous waste are especially prone to clogging the filter pores, especially as they congeal under contact with cold water. However, it has been found that agitating filter 44, including impacting or inducing vibrations within filter 44, has the effect of dislodging the grease from the pores of filter 44 to allow water to flow through the filter. Congealed grease, for example, is easily fragmented if it is shaken.

Dislodging the grease from the filter pores is advantageous in that filter 44 need not be prematurely replaced and may continue to be used for a longer time period and also helps prevent the liquid from overflowing out through the waste liquid inlet 36.

Figures 1-7, and particularly figure 7, show that liquid filtration system 20 also comprises a support member in the form of a number of, and more precisely four, L-shaped support feet 80a, 80b, 80c, 80d (collectively referred to as support feet 80) that are fixed to housing 22 for spacing housing 22 away from a ground surface on which housing 22 would rest. Support feet 80 are adjustable by means of bolts 82 engaging housing 22 and selected holes 84 in support feet 80 to allow the relative position of support feet 80 with respect to housing 22 to be adjusted. More particularly, this allows the adjustment of the height of housing 22 relative to the ground surface on which it rests.

Support feet 80 are covered with protective sleeves 86a, 86b, 86c, 86d (collectively referred to as protective sleeves 86) that are inserted over support feet 80. Protective sleeves 86 could be attached to either one of support feet 80 and housing 22 as long as they cover and protect support feet 80.

Support feet 80 are advantageous in preventing water and other elements from accumulating underneath housing 22 where unsanitary conditions could otherwise develop. The fact that support feet 80 are integrated with the housing 22, in that they are fixedly attached thereto, ensures that housing 22 will be spacedly supported over ground at all times. Support feet, by being adjustable in height, also allow liquid filtration system 20 to be more easily retro-fitted onto most sinks and many other applications having a waste liquid drain pipe.