GB2531180A

GB2531180A - Water treatment apparatus

Info

Publication number: GB2531180A
Application number: GB1522180.7A
Authority: GB
Inventors: Armstrong Damone
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-04-21
Filing date: 2011-04-21
Publication date: 2016-04-13
Anticipated expiration: 2031-04-21
Also published as: GB2490160A; GB2490160B; GB2531180B; CA2738298A1; GB201522180D0; GB201106740D0

Abstract

A water treatment apparatus comprises a settlement tank 1 to remove fats, oils, grease and solids. The apparatus comprises an inlet 2 and an outlet (3 figure 1), the inlet and outlet are located towards respective opposite ends of the settlement tank. The settlement tank has a baffle 4 extending across the settlement tank, located downstream of the inlet and upstream of the outlet. The baffle is hollow in the axial direction and preferably has a curved front (4a figure 2) or rear face (4b figure 2). A later embodiment relates to a water treatment apparatus characterised by first and second baffles wherein at least part of the second baffle 6 is above the first baffle.

Description

Water Treatment Apparatus

Field of the Invention

The present invention relates to an apparatus for use in the trealment of water and in particular to an apparatus for use in the treatment of waste water for example to remove fats, oils, grease and solids.

Background of the Invention

In many countries of the world waste water must be treated before it is released into the sewage system or into water courses. \Xiiste water from catering establishments and food processing businesses is characterised by certain classes of waste being entrained with the water.

Typically, such waste water has entrained therewith grease. other fats and oils and solids such as meat pieces, vegetable wastes, such as peelings, soil, rejected vegetable matter, coffee and other grounds, spent tea leaves, etc. Many countries have legislation requiring such wastes to be separated from waste water prior to the water being released into the sewage system or water course.

In principle, such catering and food processing wastes are not particularly difficult to separate. Vegetable wastes and meat particles tend to he heavier than water, whereas liquelied fats, grease and oils tend to he lighter than water. Hence, the wastes may he separated by gravitational settlement.

Water treatment apparatus for treating catering and food processing waste water are often referred to as grease traps or separators and comprise a settlement tank having an inlet and an outlet. Ihe outlet is hydraulically below the inlet and is connected to a dip pipe, the inlet of which is positioned to lie in the central region of the tank. if the solids and fats, oils and grease are removed regularlv such an apparatus should function reasonably well. However, the reliable functioning of such an apparatus does depend on the settlement tank being sufficiently large that the incoming waste water does not cause turbulence in the. settlement tank affecting the separated water in the region of the outlet dip pipe. Turbulence causes the separated wastes tO beconm re-entrained with the water. if this happens in the region of the outlet dip pipe, waste is likely to he discharged From the apparatus.

However, many catering estahlishnaents do not have sufficient space for a settlement tank of the size required to ensure that the settled water in the region of the outlet dip pipe is not affected by turbulence arising from wate.r entering the settlement tank through the inlet.

In order to mitigate the effects of turbulence, some grease separators include one or more baffles. Tn one such separator one baffle immediately down stream of the inlet extends downward from the upper surface of the separator. this arrests the flow of matter which rises under settlement. A second baffle downstream of the first extends upward from the base of the separator. The second baffle arrestt the flow of matter which sinks under settlement. This type of separator suffers from a nunaber of problems. First, the build up of fats, oils and grease in the first part of the separator is liable to cause blockages.

It would therefR)re he desirable to provide an inaproved water treatment apparatus where water in the region of the outlet dip pipe is not affected by turbulence caused by waste water entering the settlement tank through the inlet.

Summary of the Invention

According to the invenfion there is provided a water treatment apparatus for separafing grease and oil entrained with water, the apparatus comprising a settlement tank, an inlet and an outlet, wherein the inlet and outlet are located towards respective opposite ends of the settlement tank, and wherein the setfienaent tank includes a baffle extending across the settlement tank downstream of the inlet and upsfteam of the outlet, wherein the baffle is hollow in its axial direction.

According to the invention there is provided a water treatment apparatus conaprising a settlement tank, an inlet and an outlet, wherein the inlet and outlet are located towards respective opposite ends of the settlement tank, and wherein the settlement tank includes a first baffle extending across the settlement tank in the lower region thereoC and a second baffle extending across the settlement tank, the first and second baffles both being situated in the settlement tank downstream of the inlet and upstream of the oudet, wherein at least part of the second baffle is situated above the first baffle, the first and second baffle being spaced apart to provide a fluid path between the inlet and the outlet.

Preferably, the first baffle extends from the base of the settlement tank upwardly.

Advantageously, the first baffle includes a front Lice to the inlet side of the settlement tank and a rear face to the outlet side of the settlement tank. Preferahl the rear face extends substantially perpendicular to the base of the settlement tank and the front face lies at an angle to a perpendicular axis extending from the base of the settlement tank. Advantageouslv the angle at which the front face lies to the base of the settlement tank is in the range of 90 degrees to 135 degrees, and preferably 120 degrees. kt least a part of the front face may include a curve.

Advantageously, the front and rear faces of the first baffle form part of the base of the settlement tank.

Preferably, the space between the front and rear faces is open to its underside.

the second baffle advantageously includes a front face to the inlet side of the settlement tank and a rear face to the outlet side of the settlement tank. Advantageously, at least one of the front face and the rear face includes a curve. In one embodiment of the invention, the second baffle is substantially circular in cross-section. Advantageously, the front and rear faces each include linear portions lying parallel with one another, the linear portions of the front and rear faces being joined together by curved portions. the provision of linear portions in the front and rear faces of the second baffle provide for the apparatus to have greater storage volume for the same baffle depth of baftie as compared with a baffle of circular cross-section.

Preferabl); the second baffle is a hollow body. Advantageously the hollow body extends between the side walls of the settlement tank, providing an opening extending from one side of the settlement tank to the other.

the cross-sectional dimension of the hollow body may be consnt in the axial direction of the second baffleS. Atcriativcy, the cross-sectional dimension of the hollow body at least internally may reduce from one end in the axial direction of the second baffle, and may reduce from both ends in the axial direction of the second baffle, and may reduce from both ends in the axial direction of the second baffle to the centre of the said second baffle.

The provision of a hollow second baftie provides vo advantages. First, significant strength is added to the structure. Second, the hollow baffle may be utilised in the installation of the apparatus in a manner that prevents the apparatus from rising up in the ground where there is a high water table.

In one embodiment of the invention the lower edge of the second baffle is situated below the upper edge of the first baffle.

In another embodiment of the invention the lower edge of the second baffle is situated on substantially the same plane as the upper edge of the first baffle.

In another embodiment of the invention the lower edge of the second baffle is situated above the upper edge of the first baffle.

The front face of the second baffle maybe situated closer to the inlet than the front face of the first baffle.

The rear face of the first baffle may he situated closer to the outlet than rhe rear face of the first baffle.

Preferably, the outlet is connected to a dip pipe having an inlet end, the dip pipe extending downwardly into the settlement tank. Ihe inlet end of the dip pipe may he situated below the lower edge of the second baffle. the inlet end of the dip pipe may be situated below the upper edge of the first baffle.

Preferably, the outlet and the dip pipe are connected to a sampling bowl, and the sampling howl includes an opening, situated above the inlet and the outlet and in Fluid communication with the dip pipe.

The water treatment apparatus may include an overflo\; the overflow comprising a Fluid pathway between the. second baffle and a wall of the settlement tank situated above the second baffle.

The water treatment apparatus may he used either above ground or underground.

Advantageoush; the water treatment apparatus is formed by plastics moulding.

Preferably, the apparatus is formed as a one piece plastics moulding. Alternatively, the apparatus may be formed as multiple pieces which are then attached together.

Preferably, the baffles are Formed in the apparatus during the moulding process.

Alternatively, the baffles nmay be mounted in the settlement tank of the apparatus post manufacture of the settlement tank. For example. in the case of the second baffle having a circular cross section, the settlement tank may be rnoulded to provide aligned openings in opposite side walls of the settlement tank, and post manufacture a pipe of a corresponding sf-ic may he inserted into the openings and fixed to the side walls of the settlement tank, for example by an adhesive or welding. Another alternative wonld involve cutting holes in the side walls of the tank post nanufacture.

According to another aspect of the invention there is provided a water treaUnent apparatus comprising a settlement tank, an inlet and an outlet. wherein the inlet and outlet are located towards respective opposite ends of the settlement tank, and wherein the settlement tank includes a first baffle extending across the settlement tank in the lower region thereof, the first baffle being situated in the settlement tank downstream of the inlet arid upstream of the outlet, wherein the first baffle comprises *i front face to the inlet side of the settlement tank and a rear face to the outlet side of the settlement tank and wherein the front and rear faces are spaced apart from one another and wherein the space between the front and rear faces is open to its unerside.

Advantageously, the rear face of the first baffle extends substantially perpendicular to the base of the settlement tank and the front face lies at an angle to a perpendicular axis extending from the base of the setfiement tank. the angle at which the front face lies to the base of the settlement tank is in the range of 90 degrees to 135 degrees, and preferably 120 degrees. At least a part of the front face may include a curve.

According to another aspect of the. invention there is provided a method of installing a \viter treatment apparatus con-iprising the steps of: i) Digging a hole; ii) Lowering the water treatment apparatus into the hole; iii) Pouring concrete into the hole around the water treannent apparatus.

As the concrete is poured into the hole around the water treatment apparatus, the concrete runs into the hollow second baffle, thereby keying the apparatus into the poured concrete.

the method may include a further step, between steps i and ii above comprising inserting an elongate element through the second baffle of the water treatnient apparatus. In this case, the concrete keys with the elongate element, a pipe for example, which thereby prevents lifting of the water treannent apparatus when the apparatus is surrounded by a body of water.

The water treatment apparatus of the invention provides a number of advantages over the prior art First, the respective shapes of the first and second baffles increase the strength and rigidiiy of the settlement tank when compared to settlement tinks of the prior art where the baffles do not provide any significant secondary Hanction in terms of tank strength. Second, the slanted face of the first baffle direct water upward, and its position with respect to the second baffle ensures that as much heavy waste as possible is collected behind the iirst baffle. Third, the provision of a sampling point on the outlet allows access to the water for discharge prior to that discharge. Fourth, the position of the inlet of the dip pipe ensures that only the cleanest water exits the apparatus. Fifth, the provision of a hollow second baffle where the baffle is elongate in cross-section allows for the same depth of baffle to be provided, yet with more water storage capacity than is the case where the second baffle is circular in cross-section.

Brief Description of the Drawings

In the Drawings, which illustrate preferred embodiments of the invention and are by way

of example:

Figure 1 is a cross-sectional side view of a water tteafrnent apparatus according to the invention; Figure 2 is a side vie\v of an alternative embodiment of a tvater treatment apparatus according to the invention; Figure 3 is a top plan view of the water treatment apparatus illustrated in Figure 2; Figure 4a is an inlet end elevation of the apparatus illustrated in Figures 2 and 3; Figure 45 is an outlet end elevation of the apparatus illustrated in Figures 2, 3 and 4a; Figure 5 is a side view of a water treatment apparatus similar to that shown in Figures 2 to 4; Figure 6 is a side view of a water treatment apparatus according to the invention in situ; Figure 7 is a side view of a water treatment apparatus of the type illustrated in Figure 1 installed in a high xvater table location; and ligure 8 is a plan view of the water treatnient apparatus installation illustrated in ligure

Detailed Description of the Preferred Embodiments

Referring now to Figure 1, there is shown a water treatment apparatus for separating wastes entrained with water. The apparatus comprises a settlement tank I having an inlet 2 and an outlet 3. the outlet 3 sits slightly below the water line of the inlet so that water may flow through the apparatus under the force of gravity. Hence, in use, the settlement tank is filled to the level of the outlet 3.

The water treatment apparatus illustrated in Figure 1 is connected to a waste water outlet of a catering estabhshment. The function of the apparatus is therefore to separate out those wastes typically entrained with such waste water, such that only substantially clean water may leave the apparatus. As described above, grease and oil tend to rise to the top of the settlement tank I being lighter than water, whereas vegetable wastes, such as potato peelings, soil, etc tend to sink to the bottom of the settlement tank 1, being heavier than water. As can he seen from Figure 1, the incoming waste water tends to separate out into a body of clean water 10, a layer of grease lOa lying on till) of the body of clean water 10 and a layer of solids I 0b. Within the body of clean water 10 there remains entrained liquefied oils and fat, that is colloidal oils and fats.

These colloidal fats and greases cannot he separated from the clean water simply by gravity However, in the context of catering waste this is in general not a significant problem.

The object of the invention is to prevent waste vater debouching into the settlement tank 1 from causing turbulence in the body of water therein. Such turbulence is likely to cause re-mixing of the clean water 10, grease from the grease layer lOa and solids from the layer of solids lob.

The apparatus includes' first baftie 4 which extends upward from the base of the settlenient tank 1. and a second baffle 6 which is situated above the first baffle 4. Both the first and the second baffles extend across the settlement tank 1. The first baffle 4 has a front face 4a and a rear face 41) and a peak 4c, where the front face 4a meets the rear face 41).

The second baffle 6 comprises front and rear faces 6a, Oh, which are spaced apart and in the illustrated example are joined by curved upper and lower faces 6c, Od. the outlet 3 is situated on the downstream side of both the first and second baffles 4, 6. the upper face Gd of the second baffle 6 sits above both the inlet 2 and outlet 3. Tjence, unless the fluid pathway? or the outlet 3 become blocked (or blocked to the extent that fluid may flow into the apparatus faster than it can flow through the pathway 7 or out of the outlet 3). then the level of fluid in the settlement tank 1 may not exceed the level of the upper face Gd. In the even of a blockage, fluid may overflow the baffle 6, passing over the upper face 6d.

In the embodiment illustrated in Figure 1, the peak 4c of the first baffle is situated downstream of the face Ge of the second baffle 6. A pathway 7 through which fluid may flow is hence formed bertveen the first and second baffles 4, 6.

Settlement of grease and solids from incoming waste water is largely a function of residence time of the water in the settlement tank 1. if solids remain entrained in the water by the time they reach the face Ga of the second baffle, their path towards the outlet 3 will he arrested by the said face Ga. Entrained solids will fall downwards along the path of the face Ga.

In the event that any descending solids are attracted around the lower face 6c of the second baffle they are unlikely to find their way through the pathway? to the downstream side of the second baffle, since the entrained solids continue to fall downward through the body of water, where they encounter the face 4a of the first baffle 4. in the illustrated example, the face 4a is angled at approximately 30 degrees to the vertical to provide a steeply sloping surface, which ensures that the entrained solids continue to fall through the body of water rather than building up on the said face 4a.

Any grease that remains entrained with the clean water 10 after passing through the pathway 7 will settle out at the surface of the body of xvater.

Water reaches the outlet 3 via a dip pipe 3d, which extends below the likely lower level the gre.ase layer 10a, and hence water exiting via outlet 3 should be free of grease and oil, save for colloidal grease and oil, which as mentioned above, cannot he removed by gravitational settlement. in fact, in the embodiment illustrated in Figure 1, the dip pipe 3d extends below the peak 4c of the first baffle. this significantly reduces the likelihood of any entrained grease finding its way to the outlet 3. Not oniy is the inlet of the dip pipe 3d below the peak 4c of the first baffle, but also, the angle of the front face 4a directs water passing through pathway 7 upward and away from the dip pipe inlet.

the dip pipe 3d is attached to the underside of a bowl 3a which provides for the passage of fluid from the dip pipe 3d to the outlet 3 via* a1 outlet 3c of the bowl 3a. The bowl 3a also provides a sampling point 31) which includes an opening lying above the level of inlet 2. The bowl 3a is filled with water via dip pipe 3d, i.e. water for discharge. Sampling point 3b provides convenient access to the body of water for discharge.

The arrangement of first and second baffles 4, 6 in Figure 1 ensures that matter that is heavier than water is held on the upstreani side of those baffles, and also that the \vater going through the outlet is free of non-colloidal grease and oil.

The inlet 2 is connected to an arrangenient of pipes which separates the incoming flow into ttvo streams and directs that flow downward. As can he seen from Figure 1, the inlet 2 is connected to a t-piece 2b the free ends of which are connect to 90 degree bends 2c, winch are in turn connected to the downpipes 2d, which debouch into the settlement tank through do\vnpipes 2d, the do\vn pipes 2d having a length which ensures that incoming waste water enters the body of fluid in the. settlement tank below the layer lOa of separated grease \vhich sits in the top of the settlement tank 1.

the embodiment illustrated in Figures 2 to 4 functlons in similar manner to the apparatus illustrated in Figure 1. save that the second baffle 6 is circular in cross-section. In this embodiment, part of the rear face 4h of the first baffle is slightly curved.

the embodiment illustrated in Figure 5 functions in a similar manner to the apparatus illustrated in Figures 1 to 4. save that the second baffle 6 has the shape of a tear drop. In the embodiment illustrated in Figure 5 this results in the peale 4c of the first baffle being situated above the lower edge of the second baffle 6.

Figure 6 illustrates the water treatment apparatus of Figures 2 to 4 installed below ground-leveL The inkt 2 is connected to awaste pipe 30 of a sink 31. The settlement tank I is set into a hole dug in the ground, which has a concrete sub-base 20 therein. When the concrete of the sub-base has set the settlement tank is lowered into the hole to sit ofl the sub-base 20.

1ie space between the sides of the settlement trnk 1 and the sides of the hole in the ground is filled with concrete. Inevitibly, some concrete finds i way into the opening prcvided by the hollow baffle 6. When the concrete sets, not only are the. ouide walls of the settlement tmk supported, but the settlement tank is supported by the concrete situated in the opening of the hollow baffle.

Figures 7 and 8 illustrate an alternative instaUation method which diFFers from that illustrated in Figure 6 in that a pipe 23 is passed through the opening of the hollow I)af Be 6.

The pipe 25 rests in the curved lower surface Oc of the baffle 6. The settlement tank I is hi)wcred onto the sub-base 20. The pipe 25 may be passed through the baffk 6 P° to towering of the settlement tank 1 into the ground, or after, provided that the hole dug to receive the settlement tank 1 is sufficiently large for the pipe 23 to he passed through the baffle 6.

Shuttering 26 is erected to either side of the pipe 25 on each side of the setdemcnt tank 1.

Concrete is then poured into the shuitering where it surrounds the pipe 23. In the embodiment illustrated here the pipe 25 the thickness of the concrete to the sides of the pipe 25 is 75mm and 200mm above the pipe.

The installation methods illustrated in Figures 6 to 8 are parficuLwly useful where the water table is high as they provide for the setfiement tank to be anchored.

The water treatment apparatus illustrated in Figures 1 to S may he used above or below ground. The shape and configuration oF each oF the First and second baffles, individually and collectively increase the strength and resistance to bending as compared with those water treatment apparatus of the prior art, which include thin walled baffles with little resistance to bending.

In the event of overflow due to block--age of the fluid pathway 7, the apparatus still frunctions. In overfIosi water and entrained wastes, in particular some of those wastes at the top of the settlement tank pass over tl-e top of the second baffle. Due to the positloning of the outlet dip pipe, the water leaving the settlement tank remains clean as the grease. fits and oils separate out to the top but on the downstteam side of the second baffle.

Claims

Claims A water treatment apparatus for separating grease and oil entrained with water, the apparatus comprising a settlement tank, an inlet and an outkt, wherein the inlet and outlet are located towards respective opposite ends of the settlement tank, and wherein the settlement tank includes a baffle extending across the settlement tank downstream of the inlet and upstream of the outlet, wherein the baffle is hollow in its axial direction.
2.Awater treatment apparatus according to Claim 1, wherein the baffle includes a front face to the inlet side of the settlement tank and a rear face to the outlet side of the settlement tank.
3.Awater treatment apparatus according to Claim 2, wherein at least one of the front face and the rear face includes a curve.
4.Awater treatment apparatus according to Claim 3, wherein the second baffle is substantially circular in cross-section.
5.Awater treatment apparatus according to Claim 3 or 4, wherein the front and rear faces each include elongate portions.
6.Awater treatnaent apparatus according to Claina 3, wherein the elongate portions of the front and rear faces are joined by upper and lower curved portions.
7.Awater treatment apparatus comprising a settlement tank, an inlet and an outlet, wherein the inlet and outlet are located towards respective opposite ends of the settlement tank, and wherein the settlement tank includes a first baffle extending across the settlement tank in the lower region thereof, and a second baffle extending across the settlement tank, the first and second baffles both being situated in the settlement tank downstream of the inlet and upstream of the outlet, wherein at least part of the second baffle is situated above the first baffle, the first and second baffle being spaced apart to provide a fluid path between the inlet aud the outlet.
8. A water treatment apparatus according to Claim 7, wherein the rear face of the first baffle extends substantially perpendicuhr to the base of the setdernent tank and the front face lies at an angle to a perpendicular axis extending from the base of the settlement tank.
9.Awater treatment apparatus according to Claim 7 or 8, wherein the front and rear faces of the first baffle form part of the base of the settlement tank.