Patent Publication Number: US-2007102351-A1

Title: Waste water separator device

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
      The priority of Great Britain Patent Application No. 0522623.8 filed Nov. 5, 2005 is hereby claimed under the provisions of 35 USC §119.  
     DESCRIPTION OF INVENTION  
      The invention relates to a waste water separator device which accepts waste water, typically from the kitchen of a school, restaurant or the like, although it is equally suitable for domestic use, and separates from it grease and particulates and releases cleaner, but still dirty, waste water which can be more readily processed in water treatment works.  
      The waste water which is discharged from kitchens, particularly commercial ones, can contain a lot of grease which as the water cools and flows more slowly in the sewers can plate out onto the walls of the sewers. This causes the effective diameter of the sewers to be reduced thus reducing the volume of fluid which they can carry, and in extreme cases can cause the sewers to become completely blocked. The grease also causes particulate food matter to become trapped on the walls of the sewers attracting rats and causing health and safety issues. It is therefore preferable to pre-treat the waste water being discharged from kitchens, and other premises, to remove grease and particulate matter in order to reduce these problems.  
      Several waste water separator devices have been proposed in the past. One such device was described by the current inventors in their earlier application published under number GB 2297277 A. Other examples were described by other applicants in granted patents, numbers GB 2228751 B and EP 0529464 B.  
      However, none of these devices achieve the level of separation really required.  
      It is an object of the present invention to provide an alternative form of waste water separator device.  
      According to the present invention there is provided a waste water separator device comprising:  
      a container having a base;  
      an inlet with an exit therefrom; and  
      an outlet with an entrance thereto,  
      and defined within the container first, second and third chambers through which waste water flows along a path between the inlet and the outlet,  
      communication between the first and second chambers being by way of at least one aperture, in a wall separating the first chamber from the second chamber, close to the base of the container, and  
      communication between the second and third chambers being by way of passage of a wall separating the second chamber from the third chamber at a height above the entrance to the outlet.  
      The communication between the second and third chambers is by way of flow over and/or flow through (e.g by way of one or more apertures) the wall separating the second chamber from the third chamber.  
      Preferably the path between the inlet and the outlet is twisting or convoluted so that the waste water not only has to rise and fall to pass from the inlet to the outlet but also has to deviate from a path which appears substantially linear in plan view.  
      Preferably the inlet includes a bend towards the exit thereof to direct the waste water flowing into the device to flow around the first chamber in a relatively smooth manner. Desirably, the inlet causes the waste water to circulate slowly around part or all of the first chamber.  
      It is further preferred that the at least one aperture, in the wall separating the first chamber from the second chamber, close to the base of the container is offset from the exit of the inlet.  
      The at least one aperture, in the wall separating the first chamber from the second chamber, close to the base of the container may be offset at least 90 degrees away from the exit of the inlet.  
      The at least one aperture, in the wall separating the first chamber from the second chamber, close to the base of the container may be offset at least 160 degrees away from the exit of the inlet.  
      Preferably when the separator device is to be emptied and cleaned it is removed in its entirety from the use location. Larger embodiments of the invention can be equipped with wheels to facilitate removal. 
    
    
      Embodiments of waste water separator devices according to the invention will now be described, by way of example only, with reference to the accompanying drawings in which:  
       FIG. 1  is a cross section vertically through a first embodiment of a waste water separator device according to the invention;  
       FIG. 2  is a plan view of the waste water separator device of  FIG. 1 ;  
       FIG. 3  is a cross section vertically through a second embodiment of a waste water separator device according to the invention; and  
       FIG. 4  is a plan view of the waste water separator device of  FIG. 3 . 
    
    
      Referring first to  FIGS. 1 and 2 , a first embodiment of a waste water separator device  10  is illustrated in vertical cross section and plan view. The separator device  10  comprises a generally rectangular container  12  in a vertical orientation, having a base  12   a  and sides  12   b ,  12   c ,  12   d  and  12   e , with a lid  14  which in use is secured down such that only authorised people can open it. The manner of securing the lid  14  closed, which is not shown, can be anything appropriate for the form of the container  12  and lid  14 , for example a lock which requires a key to open it, or security seals.  
      An inner chamber  16  is located in the centre of the container  12  and in this embodiment is generally circular in cross section and extends from the base  12   a  of the container  12  to which it is sealed to a point at least approximately ⅘ths of the way up the height of the container  12 . An inlet pipe  18  passes through the side  12   b  of the container  12  and through the wall of the inner chamber  16  approximately ¾ of the way up the height of the container  12 . The inlet pipe  18  has on its inner end  18   a , within the inner chamber  16 , a bend to direct the waste water entering the device, as shown at arrow A, to flow around the inner chamber  16 , as shown by arrow S, rather than straight across it to the other side of the inner chamber  16 . This helps to ensure that the waste water flows around the inner chamber  16  in a relatively smooth manner, that is far less turbulent than would be the case if it flowed directly towards a wall of the chamber at an angle of 90 degrees or thereabouts. The relatively slow and smooth circulation within the chamber which is thereby induced assists in allowing the grease to float to the top and the particulates to sink to the bottom as the waste water slows down.  
      The separator device  10  further comprises baffles  20  which bridge the gap between the container  12  and the inner chamber  16 , to divide the lower part of the container  12  outside of the inner chamber  16  into two outer chambers  22  and  24 , up to a height approximately ⅓ of the way up the height of the container  12 . The inner chamber  16  has apertures or holes  28  in its wall which communicate with the first outer chamber  22  near, but not immediately adjacent to, the base  12   a  of the container  12 . The holes  28  are positioned such that they are offset from the inlet  18  in terms of both height and angular position in order to ensure that the waste water cannot flow into the inner chamber  16  from the inlet  18  and directly out of the inner chamber  16  into the first outer chamber  22 , but has to flow at least part way around the inner chamber  16  first. This again assists in allowing the grease sufficient time to float to the top and the particulates sufficient time to sink to the bottom as the waste water slows down.  
      Outlet pipes  26  are provided in the walls  12   c  and  12   e  of the container  12  from the second outer chamber  24 . The outlet pipes  26  pass through the walls  12   c  and  12   e  at a height approximately ½ the way up the height of the container  12 . However, the outlet pipes  26  start with entrances  26   a  at their lower ends below the height of the baffles  20  and have open upper ends  26   b  above the height at which they pass through the walls  12   c  and  12   e  of the container  12 .  
      Although the device  10  is provided with two outlet pipes  26  this is only for adaptability when fitting the device for use, as only one outlet pipe  26  typically needs to be used and the other can be blanked off if it is not required. The outlet pipes could also be provided in other locations and not exactly those shown, provided they communicate with the second outer chamber  24 .  
      The device  10  is used as follows. The inlet pipe  18  is connected to a waste water inlet pipe (not shown) comprising the source of waste water (e.g. where the waste from a sink passes out of the wall of the premises concerned, the device being located outside the building) and one or both outlet pipes  26  are connected to a waste water outlet pipe (also not shown) which comprises the outlet of waste water for the premises concerned (e.g. a pipe that goes to the drains). Preferably, the connections to the waste water pipes are by way of quick-release fittings. The device is then charged with fresh water to the level shown with a chain line  30  in  FIG. 1 , this level being achieved in all three chambers  16 ,  22  and  24  by means of the communication between the inner chamber  16  and the first outer chamber  22 , and because the level is above the height of the baffles  20 , allowing water to flow across from the first outer chamber  22  to the second outer chamber  24 .  
      When waste water enters the device  10  (as shown by arrows A and B) it flows relatively smoothly around the inner chamber  16  and as it slows down any grease contained in the waste water rises to the top of the inner chamber  16 , whilst some of the (typically heavier) particulates within the waste water will settle to the bottom of the inner chamber  16 , below the holes  28 . Waste water then flows through the holes  28  between the inner chamber  16  and the first outer chamber  22  (as shown by arrows C), and at this stage will still include some grease and some (typically lighter) particulates. Because the holes  28  are located above the base  12   a  the particulates which have fallen to the bottom of the inner chamber  16  will not pass through the holes  28 .  
      Communication between the first and second outer chambers  22  and  24  is over the top of the baffles  20  (as shown by arrows D), which means that very few if any remaining particulates pass from the first outer chamber  22  to the second outer chamber  24 , but rather settle to the bottom of the first outer chamber  22 . Any grease which has passed out of the inner chamber  16  will rise to the top of the water in the container  12  at the level  30 , but this is well above the bottoms  26   a  of the outlet pipes  26  and therefore will not be able to enter the outlet pipes  26  and pass out of the device  10  to the drains with the processed water (as shown by arrows E).  
      Referring now to  FIGS. 3 and 4 , a second embodiment of a waste water separator device  100  is illustrated in vertical cross section and plan views. The separator device  100  comprises a generally rectangular container  112  in a horizontal orientation, having a base  112   a  and sides  112   b ,  112   c ,  112   d  and  112   e , with a lid  114  which in use is secured down such that only authorised people can open it. As for the first embodiment the manner of securing the lid  114  closed, which is not shown, can be anything appropriate for the form of the container  112  and lid  114 , for examples a lock which requires a key to open it, or security seals.  
      A divider  116  is located in the centre of the container  112  and is generally circular in cross section and extends from the base  112   a  of the container  112  to which it is sealed to a point approximately ¾ of the way up the height of the container  112 . An inlet pipe  118  passes through the side  112   e  of the container  112  approximately ¾ of the way up the height of the container  112 . The inlet pipe  118  has on its inner end  118   a  a bend to direct the waste water entering the device, (as shown at arrow F), outwardly and downwardly such that it flows relatively smoothly around the container  112  rather than directly at, i.e. perpendicular to, one of the walls  112   b ,  112   c ,  112   d  and  112   e . A baffle  119  is provided between the wall  112   g  of the container  112  and the divider  116  beneath the inlet pipe  118 , to prevent waste water continuing to flow around the container  112 .  
      The separator device  100  further comprises a baffle  120  which separates the divider  116  into first and second inner chambers  122  and  124 , up to a height approximately ⅔ of the way up its height. The divider  116  has holes  128  in its wall which communicate between the container  112  and the first inner chamber  122  near the base  112   a  of the container  112 . The holes  128  are positioned such that waste water exiting the inlet  118  has to flow at least part way around the container  112  before it can flow through the holes  128  into the first inner chamber  122 .  
      An outlet pipe  126  is provided from the second inner chamber  124  through the divider II  6  and the wall  112   e  of the container  112 . The outlet pipe  126  passes through the divider  116  and the wall  112   e  at a height approximately ½ way up the height of the container  112 . However, the outlet pipe  126  starts with an entrance  126   a  at its lower end below the height of the baffle  120  and has an open upper end  126   b  above the height at which it passes through the divider  116  and wall  112   e  of the container  112 .  
      Although the separator device  100  is described above including a single outlet pipe  126 , it may be provided with more than one outlet pipe in order to provide alternative modes of connection if required.  
      The separator device  100  is used in a very similar manner to the separator device  10 , as follows. The inlet pipe  118  is connected to the source of waste water (e.g. directly to the waste from a sink, the device being located inside the building) and the outlet pipe  126  is connected to the outlet of waste water for the premises concerned (e.g. a pipe that goes through the wall of the building and to the drains). The device is then charged with fresh water to the level shown with a chain line  130  in  FIG. 3 , this level being achieved in all three chambers  116 ,  122  and  124  by means of the communication between the container  112 , the first inner chamber  122 , and because the level is above the height of the baffle  120  allowing communication between the first and second inner chambers  122 ,  124 .  
      When waste water enters the device  100  (as shown by arrows F and G) it flows relatively smoothly around the container  112  and as it slows down any grease contained in the waste water rises to the top of the container  112 , whilst some of the particulates within the waste water will settle to the bottom of the container  112 , below the height of the holes  128 . Waste water flows through the holes  128  between the container  112  and the first inner chamber  122  (as shown by arrows H), and this will still include some grease and some particulates. However, communication between the first and second inner chambers  122  and  124  is over the top of the baffle  120  (as shown by arrow I), which means that very few if any particulates pass from the first  122  to the second inner chamber  124 , but rather settle to the bottom of the first inner chamber  122 . Any grease which has passed out of the container  112  will rise to the top of the water in the first and second inner chambers  122  and  124  at the level  130 , but this is well above the bottom  126   a  of the outlet pipe  126  and therefore will not be able to enter the outlet pipe  126  and pass out of the device  100  to the drains with the processed water (as shown by arrow J).  
      Over time the amount of grease and particulates trapped in the separator devices  10  and  100  will of course increase. Thus, periodically, the separator device  10 ,  100  will need to be removed and replaced with a fresh one duly charged with fresh water. The separator device  10  or  100  which contains the grease and particulates is disconnected from the waste water inlet pipe and the waste water outlet pipe and is preferably removed from the premises and taken to a treatment depot where it is emptied and cleaned ready for reinstallation elsewhere. To ease removal of the separator device  10  it may conveniently include wheels (not shown). Preferably the greases removed from the separator device  10 ,  100  are recycled in some way, e.g. they may be used to fuel vehicles in place of diesel, whilst the particulates will be suitably disposed of. The frequency of replacement of the separator devices  10  or  100  at any particular location will depend on the type of premises, but may for example be about 14 days.  
      If the waste water separator devices  10  and  100  are to achieve the best possible separation of grease and particulates it is important that the flow of waste water along the path from the inlet to the outlet is relatively smooth, i.e. not turbulent as turbulent flow reduces separation. In addition it is important that the waste water cannot flow too rapidly along the path from the inlet to the outlet, but rather must slow down after entering the separator device and preferably to assist this the path must not be a straight line from the inlet to the outlet, but rather must be twisting or convoluted.  
      It will be understood that the relative dimensions quoted above are approximate and not limiting. However, it is necessary that the bottom of the inlet  18 ,  118  be above the bottom of the outlet  26 ,  126 , in order to prevent waste water lying within the inlet  18 ,  118  (which will cause a spillage when the device is disconnected and also lead to settlement of particulates and/or grease within the inlet). Also, the top of the apertures  28 ,  128  must be below (and preferably substantially far below) the top of the wall  20 ,  120 .  
      In the embodiments shown the outlets  26 ,  126  have open upper ends  26   b ,  126   b . This is firstly to prevent a siphoning action taking place at the outlet. Also, if the entrance  26   a ,  126   a  to the outlet becomes blocked by grease or particulates, waste water can continue to flow to the outlet by way of the open upper ends  26   b ,  126   b . Finally, the open upper ends  26   b ,  126   b  facilitate thorough cleaning of the outlet  26 ,  126 ,  
      The capacity of the waste water separator device can be chosen to suit the application. In a domestic application the capacity could be around 40 litres for example, whilst in a commercial application (with a typically greater waste water flow) the capacity would typically be greater than this.  
      When used in this specification and claims, the terms “comprises” and “comprising” and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.  
      The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.