HK1083322B - Improved separator for immiscible liquids - Google Patents

Abstract

A separator (10, 150, 182, 200) provides improvements for better separation of an effluent into constituent parts and greater ease of use. A tapered basket (60) provides improved flow and better filtration. A baffle (64) directs effluent into the basket with greater force. An asymmetrical flange (54) prevents mis-orientation the basket (60) and baffle (64). An improved oil valve (90) provides a locking mechanism to prevent dislodging of the valve during cleaning. An alternative valve uses a sensor to sense an oil/water interface and close the oil valve appropriately. A top seal (142) prevents leakage of effluent at connection points with the lid (15) of the housing (14). An underground unit (150) allows below floor level installation of the separator. A bidirectional unit (182) can be reversed to provide flow in either direction. A dual purpose tank (170) can be used to store both separated oil and oil from operations for common removal.

Description

Improved separator for immiscible liquids

Cross reference to related patent

The present application claims benefit from the filing date of co-pending U.S. provisional application No.60/556832 entitled "improved separator for immiscible liquids" filed on 26.3.2004 and co-pending U.S. provisional application No.60/582993 entitled "improved separator for immiscible liquids" filed on 25.6.2004.

Technical Field

The present invention relates to a liquid separation device, and more particularly to a device for separating oil and/or grease from water.

Background

In some industries, particularly the food industry, it is desirable to separate liquid fats, oils and oils from the wastewater prior to discharging the water into a sewage system. The waste water can be discharged, for example, from a washing device for washing dishes and cooking utensils. If the grease and fat solidify in the sewage system, clogging can occur and require costly unclogging.

In addition, there are movements in many places to recycle grease and oil.

A commercially available separation device of the type described in european patent EP890381B1 is shown generally in fig. 1a and 1B. Fig. 1a shows an external perspective view of the separating apparatus 10. An effluent (containing two or more immiscible liquids of different densities, typically water entrained with oil, grease, dissolved fat and other particulates) is received at inlet 12 which provides access to housing 14, including removable cover 15. The effluent is heated using a probe heater connected to an electrical connection. As described below, these immiscible liquids are separated within housing 14 and low density substances (e.g., grease and oil) are discharged into reservoir 18. The high density substance (e.g., water) is discharged from the water outlet 20. Debris accumulates at the bottom of the housing 14. The debris can be periodically discharged through the debris outlet 2.

The operation of the separating apparatus 10 will now be described in more detail with reference to figure 1B (and EP890381B1, which is incorporated by reference). Fig. 1b shows a side sectional view of the separating apparatus 10. A coarse filtration chamber 24 is defined between the housing 14 and a control plate 25 extending across the width of the housing. As the effluent enters the coarse filtration chamber 24 through the inlet 12, it passes through a filter basket 26 (shown in more detail in fig. 2) that filters out solid particles such as undissolved fat and other food particles.

After passing through the filter basket 26, the effluent enters a separation chamber 28 defined by a control plate 25, a control plate 30 (which extends across the width of the housing), a top plate 32 and the bottom of the housing 14. The separation chamber has two outlets: (1) through the float valve 34; and (2) through a channel 36 provided between the bottom of the control panel 30 and the bottom of the housing 14. The top plate 32 angles upward from the bottom of the control plate 25 toward the control plate 30.

The weir 38, which extends across the width of the housing, defines with the control plate 30 and the housing 14 a water (high density liquid) discharge chamber 40. An outlet 20 is provided through the housing.

In operation, as the effluent enters the separation chamber 28, the low density liquid (grease/oil) rises. The flow rate through the separation chamber 28 is set so that the low density liquid can separate from the water and float upwardly onto the surface of the water where it is contained beneath the inclined roof 32.

The inclined roof 32 forces the low density liquid to accumulate at the inlet to the float valve 34. The float valve 34 is shown in more detail in figure 4. The float valve 34 uses a ball that floats at the interface between the high density liquid and the low density liquid. When the high density liquid reaches a predetermined height, the ball rises to a height that stops the flow from the separation chamber 28 to the container 18.

As the water stream passes through the separating apparatus 10 it must rise above the top of the weir 38 for discharge. Thus, the water in the separation chamber 28 tries to rise to approximately the same height. Since the top of the separation chamber 28 is below the top of the weir plate 38, the hydrostatic pressure of the water upward will push the grease/oil located at the top of the separation chamber 28 through the valve 34. However, water cannot pass through the valve 34 because the float valve will prevent it from passing. Thus, once all of the separated grease/oil is forced out of the separation chamber, the valve will remain closed until more grease/oil has accumulated.

The separated water passes through the passage 36, over the weir 38 and out the outlet 20. Debris in the water will collect at the bottom of the housing 14 and cannot rise over the weir plate 38. A debris valve 22 provided at the bottom of the housing 14 may be periodically opened and the flow of water exiting the valve may flush debris out.

In many areas of use of the separating apparatus 10, particularly in the food industry, it may be assumed that employees operating and maintaining the separating apparatus are in relative motion between employers. Therefore, the operational and maintenance aspects of the separator must be such that they are easily accessible to unskilled personnel. Such as periodic cleaning of the various components of the separating apparatus, such as a float valve, if not operated correctly, can lead to undesirable consequences such as the ingress of water into the oil/grease container or the egress of oil/grease from the outlet 20.

Also, it is desirable to increase the flow rate of the liquid through the separation chamber, since oil and grease are inherently viscous and tend to accumulate on hard surfaces.

Accordingly, there is a need in the industry for improved separation devices.

Disclosure of Invention

In one aspect, the present invention provides a separation apparatus comprising: a vessel having an inlet, an inlet chamber, a separation chamber and an outlet chamber, and the inlet feeds the effluent into the inlet chamber, the inlet chamber communicating with the separation chamber through a first passage, and the separation chamber communicating with the outlet chamber through a second passage. A filter basket having at least one tapered side is disposed in the inlet chamber below the inlet with one tapered side disposed at an angle relative to an adjacent sidewall of the inlet chamber.

In another aspect of the invention, the baffle deflects effluent into the filter basket with greater force.

In another aspect of the invention, the asymmetric flange prevents mis-orientation of the filter basket and baffle.

In another aspect of the invention, the continuous base and continuous flange on the filter basket may prevent floatable solids from floating up around the filter basket and carrying with it oil, thereby interfering with the oil valve ball base.

In another aspect of the invention, the self-closing debris valve eliminates the possibility of the debris valve remaining open, which would otherwise overheat the heater, burn and smoke the oil.

In another aspect of the invention, the improved oil valve provides a locking mechanism to prevent the valve from shifting during cleaning.

In another aspect of the invention, the valve uses a sensor to sense the oil/water interface and close the oil valve appropriately.

In another aspect of the invention, the tip seal enables input effluent to overfill the inlet chamber without leaking out past the connection on the housing cover.

In another aspect of the invention, the underground unit enables the separation apparatus to be installed below the ground surface.

In another aspect of the invention, the bi-directional unit can be installed in a manner that allows flow in either direction, thus eliminating the need to manufacture and design a device that flows from left to right or from right to left.

In another aspect of the invention, a dual purpose vessel may be used to store the separated oil and oil obtained from the operation for co-removal.

Drawings

For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

FIGS. 1a and 1b show perspective and cross-sectional views of a prior art separation device;

FIG. 2 shows a prior art filter basket used in the apparatus of FIGS. 1a and 1 b;

figures 3a to 3d show perspective, top, front and side sectional views respectively of an improved filter basket;

FIG. 4 shows a prior art float valve for use in the separation device of FIGS. 1a and 1 b;

FIG. 5a shows a cross-sectional view of the improved float valve;

FIG. 5b shows a perspective view of the housing of the improved float valve;

FIG. 5c shows a top view of the improved float valve;

FIG. 6a shows a block diagram of an improved valve for replacing the ball valve of FIG. 4;

FIGS. 6b to 6d show cross-sectional views of a butterfly valve, a gate valve and a ball valve, respectively;

FIGS. 7a to 7c show an improved separating apparatus having a low friction surface, enhanced heat dissipation and debris removal, and capable of preventing leakage, respectively;

FIG. 8 shows an improved separation device that may be installed in the ground;

FIG. 9 shows a tool for cleaning the separating apparatus of FIG. 8;

FIG. 10 shows a separator device incorporating a bulk storage container for grease control integration;

FIG. 11 shows a bi-directional separation device;

FIG. 12 shows an embodiment that uses a vent tube to remove air trapped in the separation chamber;

FIGS. 13a and 13b show a side cross-sectional view and a top view, respectively, of a ball valve embodiment having an integral vent tube;

fig. 14 shows another embodiment of the separation device 200.

Detailed Description

The present invention will be better understood with reference to the accompanying figures 1-11, wherein like elements in the various figures are given like reference numerals.

Figure 2 shows a prior art filter basket 26. The filter basket has a front face (facing the housing at the inlet 12) and a rear face (facing the control panel 25) with perforations 50 thereon as at the bottom of the frame. Since the front face is relatively flush with the housing 14 and the back face is relatively flush with the control plate 25, and the ends are not perforated, almost all of the effluent flows through the holes in the bottom of the filter basket. Over time, food particles will accumulate on the bottom of the filter basket 26, thereby severely restricting flow into the separation chamber 28.

Other problems relate to the removal and replacement of the filter basket 26. The prior art uses a handle 52 which ends through holes on either side of the filter basket. The filter basket 26 has flanges 54 on either side; these flanges 54 typically seat against support clips 56 formed on either side of the housing of the coarse filtration chamber 24. To accommodate the exposed end of the handle 52 when the filter basket is removed or replaced, a slot 58 is formed in the support clip 56 through which slot 58 the end of the handle can pass.

These slits 58 prevent a complete seal between the flange 54 and the prop clip 56 during operation. Some food particles in the effluent may pass through the slits 58, thereby bypassing the filter basket 26. Food particles can also pass through the narrow gaps between the filter basket front edge and the outer body 14, and between the filter basket rear edge and the control plate 25. Too many food particles entering the separation chamber 28 will block the float valve 34, causing water to enter the oil collection chamber 18.

Figures 3a to 3d show a perspective view, a top view, a front cross-sectional view and a side cross-sectional view, respectively, of the improved filter basket 60. The improved filter basket increases the effective effluent flow rate, prevents solid particles in the effluent from bypassing the filter basket filter mechanism, and facilitates separation of the effluent in the separation chamber 28.

Unlike the vertical sides of the filter basket 26, the tapered filter basket 60 has tapered sides that slope away from the housing 14 and control plate 25. In addition, all four sides are perforated. Thus, a greater filter basket surface area is separated from the converging walls for more efficient flow through the filter basket 60. The apertures 62 can have a smaller diameter due to the larger area occupied by the apertures 62 without affecting the flow of effluent through the filter basket. In the prior art, hole 50 has a diameter of about 11/64 inches, while hole 62 may have a diameter of about 1/16 inches (0.15875 cm). This enables the filter basket 60 to collect smaller particles for more effective coarse filtration. In addition, more debris can be collected before the filter basket needs to be emptied, as the filter basket continues to effectively filter effluent even when the bottom is covered.

Another improvement is the addition of an angled baffle 64 to the filter basket 60. The baffle 64 deflects water from the inlet 12 toward the bottom of the filter basket 60. The cutout 64a in the baffle plate 64 faces the inlet 12. As the effluent enters the coarse filtration chamber 24, the baffle directs the effluent downward to help drive the oil and grease under the control plate 25. In addition, as the effluent strikes the baffle 64, it is driven through a layer of oil, which helps saturate the chemical emulsions, causing the emulsions to release oil.

The handle 68 of the filter basket 60 is mounted on top of the baffle plate 64. The slots 58 shown in figure 2 are no longer required because the handles do not extend from the sides of the filter basket 60.

With the addition of the baffle 64, it is important that the filter basket 60 be oriented correctly (so that the baffle deflects the effluent downwardly rather than upwardly). Carelessness in replacing the filter basket 60 can cause problems in the operation of the separator apparatus 10. To prevent misplacement replacement, the filter basket 60 has asymmetric flanges 54a and 54 b. As shown in fig. 3a-d, the flanges 54a are wider than 54b and the support clips 56a are wider than 56 b. If the filter basket 60 is replaced in the reverse direction, the mismatch between the support clips 56a-b and the flanges 54a-b will prevent the filter basket from seating properly (and the lid will not close). This will alert the operator to the need to reverse the filter basket. The front and rear flanges 54c and 54d form an integral lip that completely surrounds the filter basket 60 for complete sealing.

Fig. 4 shows a float valve 34 used in the prior art. The float valve 34 includes a ball 70 within a housing 72. The ball 70 is held within the housing 72 by a grid 74. The insert 76 includes a mating portion 78 for mating with the housing 72 above the ball 70 and an outlet portion 79 for communicating with the oil/grease reservoir 18. A passage 80 is formed in the insert 76 through the mating portion 78 and the outlet portion 79 and has a tapered opening 82 at the end of the passage 80. The passage 80 is connected to an outlet 84. An O-ring 86 seals mating portion 78 and housing 72. As noted above, the ball 70 is designed to float at the interface between two immiscible liquids (e.g., water and oil/grease). As the water rises, the oil/grease is propelled into the passage 80 where it is discharged through the outlet 84 into the oil/grease reservoir 18. Once all of the low density liquid (oil/grease) has been pushed into the passage 80, the ball 70 rests against the tapered opening 82, thereby closing the passage. In this way, only low density liquid can pass through the channel 80.

Since oil and grease will pass through the passages 80 and 84 to the oil/grease reservoir 18, these passages 80 and 84 must be periodically cleaned to remove solidified material. To do this, a brush is inserted into the channel 80 from above or into the channel 84 from the side, and a scraping up and down motion is used to remove the solidified oil/grease within the channel 80. During this cleaning process, the mating portion 78 is easily displaced from the housing 72, thereby causing the valve 34 to malfunction.

A side cross-sectional view of a modified float valve 90 that may be used in place of the float valve 34 is shown in fig. 5 a. The float valve 90 includes a mating portion 78 having two projecting locking pins 92. The housing 72 includes two vertical channels 94 that form an L-shape with corresponding horizontal channels 96 for receiving the pins 92. The mating portion 78 is engaged within the housing 72 by aligning the pin 92 with the vertical channel 94, inserting the mating portion 78 into the housing 72 until the pin 92 reaches the end of the vertical channel 94, and then rotating the pin within the horizontal channel 96 to lock the mating portion within the housing 72.

Fig. 5b shows a perspective view of the housing 72 showing the vertical channel 94 and the horizontal channel 96. Fig. 5c shows the insert 76 in a locked position within the housing 72.

Another problem associated with the float valve 34 is that which can occur if the ball 70 sticks to the mating portion 82. This problem may occur because oil/grease will coat both surfaces during normal operation of the separating apparatus 10.

Figure 6a shows a schematic view of an alternative embodiment of the valve without the use of a floating ball. In fig. 6a, the sensor 100 can detect the interface position between two immiscible liquids. When the interface has reached a predetermined height, the sensor sends a control signal to the actuator 102. In response to the control signal, the actuator closes the valve 104 that controls flow between the oil/grease inlet 106 and the oil/grease outlet 108.

Fig. 6b to 6d show three valves (other valve types may be used) that may be applied to the valve 104. Fig. 6b shows a side cross-sectional view of the butterfly valve 110. The butterfly valve is operated by rotating the disc 114 within the cylindrical housing 112. When the surface of the disk 114 is aligned parallel to the axis of the cylindrical housing, the valve 110 is in an open state; the valve 110 is in a closed state when the surface of the disk 114 is perpendicular to the axis of the cylindrical housing 112.

Fig. 6c shows a side cross-sectional view of the gate valve 120. In the gate valve, a gate 122 is provided in a pipe 124 to prevent flow or is withdrawn from the pipe 124 to allow flow.

Figure 6d shows a side cross-sectional view of the ball valve 130 (not to be confused with the float valve 34). The ball valve incorporates a ball 132 with a cylindrical bore 134 through the centre of the ball. When the orifice is aligned with the inlet 136 and the outlet 138, liquid may flow from the inlet to the outlet. When the orifice 134 is rotated to a position where it is not in communication with the inlet 136 and the outlet 138, liquid is no longer able to pass through the valve.

The ball valve 130 is a preferred embodiment of the present invention because the rotating operation of the valve between the open and closed positions tends to scrape off solidified oil/grease at the inlet and outlet. The valve is therefore somewhat self-cleaning.

Figure 7a shows a modification of the separating apparatus 10 to improve the flow of liquid (and debris) within the separation chamber for improved operation. First, the inside of the housing 14 and the surfaces of the control plate 25, top plate 32, control plate 30 and weir plate 38 may be coated with a teflon coating 39 or another non-stick coating 39 to improve flow and reduce friction and adhesion between the oil/grease/debris and these surfaces.

In addition, fig. 7a shows an improvement to heating, particularly the liquid in the separation chamber 28. In the prior art, probe-type heating elements are used. This presents some problems. First, the heater is mounted on the outside of the unit where it may be inadvertently touched by an employee, or even loosened. Second, the surface area of the heater is relatively small and therefore the heat is concentrated.

In fig. 7a, several alternatives for heating the liquid in the separation chamber 28 are shown. These alternative methods may be used alone or in combination. A first alternative uses a heater blanket 140 disposed on the housing bottom 14. This eliminates any protruding housing for the heater and allows a greater surface area to be heated, keeping the temperature relatively constant across the separation chamber 28.

A second alternative uses induction heating to heat the top plate 32 and/or the valve 34. Since the top plate 32 and valve 34 are in nearly constant contact with the oil/grease, these components can be heated by induction, providing the most efficient heat to keep the oil/grease as liquid as possible. Inductive heating of top plate 32 and/or valve 34 may be used in conjunction with heater blanket 140.

Additionally, in FIG. 7a, a self-closing valve 147 is employed as the debris valve. The valve 147 is manually held open for a sufficient period of time (typically about 10 seconds) so that debris is forced out of the chamber by the water pressure and the valve closes immediately once the operator's hand is removed from the valve handle. This prevents operation of the device with the debris valve open, allowing effluent to flow directly out of the debris valve; causing the heater to overheat and burn and/or overheating the oil and smoke.

Figures 7a, 7b and 7c show top and bottom seals for use in the improved separation device. A top seal 142 is formed around the perimeter of the housing 14 and on top of the control panels 25 and 30 to form a continuous seal. In the preferred embodiment, the seal 142 is mechanically mounted to the housing 14 and control panel in the manner shown in FIG. 7 c. In fig. 7c, the sealing material is preferably in the form of a hollow neoprene tube or similar flexible hollow tube secured to the edge of the housing 14 and to the control panels 25 and 30 by a mechanical clamping mechanism 144. In the embodiment shown, the mechanical clamping mechanism includes teeth 146 that when pushed onto the housing edges will catch on the edges to form a secure mechanical bond. Any gaps between the strips of material should be filled with a sealing compound.

In operation, the top seal 142 can withstand a significant water pressure and only the weight of the lid 15 keeps it in contact with the seal 142. Thus, if water were to rush through the inlet 20, the water would remain within the housing 14 and would not escape from the coarse filtration chamber 24 or the water discharge chamber 40 into the interior chamber 148 of the housing 14 where it could become rancid.

The prior art mechanisms use compressed foam secured to the lower edge of the lid by self-adhesive tape and form a seal by using a lid clamp to hold the lid to the body. This makes it difficult for the user to reach the unit. Also, the clamped cover prevents the operator from properly maintaining the unit.

Another bottom seal 149 is mounted around the bottom edge of the housing. Also, the bottom seal 149 is preferably in the form of a hollow neoprene tube that is secured to the edge of the housing 14 using a mechanical clamping mechanism 144 as shown in FIG. 7 c.

The prior art methods of sealing the separating device to the floor, for example by caulking, have bonding problems especially in grout lines. As these units tend to be retrofitted to existing hotels, grease embedded in the grout prevents the bonding, allowing water from floor cleaning to leak under the unit. Also, caulking complicates the movement of the unit. Placing the unit on the legs so that the floor can be cleaned under the unit increases the height of the unit, thereby reducing the active fall of effluent from the sink and dishwasher drain.

It has been shown that the bottom seal 149 can effectively seal the unit to the floor and is particularly effective in sealing grout lines because the weight of the unit holds the bottom seal 149 firmly within the grout line.

Fig. 8 shows an embodiment of a separation device 150 which has the advantage that it can be used in an embodiment in the ground. For purposes of illustration, the separator 150 is shown with the prior art heater 16 and float valve 34, it being understood that other modifications described herein may be used in place of these components.

In fig. 8, the filter basket 60 performs coarse filtration of the effluent received through the inlet 12. The control panel 25 has a sloped portion 152 to improve fluid flow through the filter basket 60 (this improvement can be used in other configurations as well). The downwardly sloping bottom control plate 154 has a V-shape (or channel) to capture debris and is preferably coated with polytetrafluoroethylene. The V-shaped bottom control plate transitions into weir plate 156 to maintain a V-shape that slopes upward toward the desired predetermined height to create hydrostatic pressure on the separated oil at valve 34. A control panel 158 is connected to the top of the housing 14 and is provided with a passage 160 through which separated water flows. The control plate 158 includes an enlarged portion 162. The heater 16 is disposed through the ceiling 32 within the compartment 164. Separate from the compartment 164, the area above the top plate 32 may preferably serve as a sump 166 in the removable container for oil/grease from the oil/grease valve 34. Access to the conical filter basket 60, sump 166, compartment 164 and oil valve 34 may be gained by removing one or more lids (not shown) on the top of the housing 14. If debris is to be separated from the water, a water outlet 168 is provided above the debris valve 170. Alternatively, a single outlet may be provided for treating both water and debris. A mesh screen 172 is provided in front of the water outlet 168 to filter out debris.

In operation, debris from the effluent will collect at the floor 154 and will be drawn toward the lowermost portion of the "V" shaped plate 154 at the interface with the weir plate 156. The flow of water through the passage 160 will push the debris up the passage 160. The enlarged portion 162 of the channel will create a vortex and additional suction to push the debris up and over the top of the weir plate 156. The debris will fall toward the debris valve 170, which may be periodically opened to a debris outlet or separately collected in a receptacle connected to the debris valve 170. The remaining water flows out of the water outlet 168 into the sewerage system.

Over time, some debris will collect on the weir plate 156. Fig. 9 shows a scraper that matches the profile of the weir 156 to remove such debris.

Preferably, all inside surfaces of the separating apparatus 150 are coated with polytetrafluoroethylene to reduce drag and improve flow.

Fig. 10 shows a schematic of a separation device with a large grease container for containing grease/oil separated from the effluent and used grease/oil from operations such as from a fryer. In this embodiment, the underground separation apparatus 150 (which may also be of the type shown in figures 1-7 a-c) is connected to a storage vessel 170 which is large enough to hold all of the waste oil/grease from the effluent and operation. A conduit 173 connects the valve 34 with the storage container 170. The opening 174 enables a worker to pour oil/grease into the storage container, for example, from a tank. Alternatively, the oil/grease from the job may be pumped directly to the container 170. The heater 176 heats the contained oil so that it does not solidify. Valve 178, typically a quick-disconnect valve, provides a suitable connection for an oil pump used to pump oil/grease from container 170 for recovery. A conduit 180 is disposed between the valve 178 and the bottom of the container 170.

In operation, the embodiment shown in fig. 10 enables a business to solidify all of the oil/grease for removal by a collection company (typically an outside contractor or municipality). The same design enables the collection company to collect all used oil/grease from the restaurant. By using an underground structure, oil/trash cans can be eliminated from behind restaurants or other businesses.

Fig. 11 shows an embodiment of an above-ground bi-directional separation device 182 (with the cover 15 removed), i.e., the valve 34 and heater 16 may be provided on either side of the housing 14. The housing 14 includes two oil valve housings 72, one of which will receive the valve 34 and the other of which will have a plug mounted thereon. The container 18 is mounted through an opening 186 in the side of the valve 34, the other opening 186 being closed by a plate. Holes 186 have slotted holes adjacent to them for mounting container 18 or support member or blank 14. Threaded connections 188 are provided on either side of the housing 14 for receiving the heater 16; the side not containing the heater is closed with a threaded plug.

The embodiment shown in fig. 11 enables the separation device 182 to be installed in either flow direction, which reduces the cost that must be maintained and enables the most efficient installation within the enterprise. Additionally, if the galley is re-modified (commercial galleys on average are modified every five years), the orientation of the separating apparatus 182 may be changed to accommodate changes in flow through the duct.

Fig. 12 shows an embodiment for removing air trapped in the separation chamber 28. In certain situations, such as start-up, the flushing of effluent with entrained bubbles into the separation chamber 28 may cause the balls 70 to stick to the tapered openings 82 (see fig. 5 a). When entrained bubbles separate from the effluent, they can keep the ball 70 pressed against the tapered opening 82 and keep the valve closed. It has been found that daily cleaning of the valve can reduce this problem, but as the entrained air in the separation chamber 28 escapes through the valve it will push the oil/grease in the valve towards the person cleaning the valve.

In fig. 12, a vent tube 190 is in communication with the separation chamber 28 (in the illustrated embodiment, the vent tube 190 is disposed through the unused valve housing 72, but it may be disposed through any suitable portion of the top plate 32). The vent tube 190 extends to the vicinity of the lid 15 so that hydrostatic pressure cannot force oil/grease out of the vent tube 190. Alternatively, the vent tube 190 may feed a ball valve so that any oil/grease emanating from the vent tube 190 will be fed into the container 18.

In operation, since the vent tube is in direct communication with the separation chamber 28 without the ball valve interrupting the communication, air can always exit the separation chamber through the vent tube 190, and therefore the air does not cause the ball valve to close incorrectly.

It should be noted that animal fat may solidify in the vent tube 190. Thus, the snorkel 190 should be kept hot by electrical tracking and insulation or by other means.

Fig. 13a and 13b show side cross-sectional and top views, respectively, of an embodiment of the ball valve 34 with an integral vent tube 190. In this embodiment, a breather tube hole 191 is formed through the mating portion 78, and a tube 190 extends upwardly from the hole 191 to a height near the lid 15, or other height that ensures that hydrostatic pressure does not force oil/grease out of the breather tube 190. In addition, fig. 13a and 13b show the outlet 84 as a channel rather than a conduit. The trench structure is generally easier to clean and uses less material.

Fig. 14 shows another embodiment of the underground separation apparatus. This embodiment is similar to the embodiment of fig. 8, with container 18 being disposed above top panel 32 so that it is accessible by removing cover 15. The heater 16 is disposed below the top plate 32 and has an extension 16a to provide additional surface area to heat the effluent. The operation of the separating apparatus 200 is as described above.

This embodiment provides a ground separation device that can be used, for example, in a restaurant work area. The container is easily accessed and removed to deliver oil/grease to the storage container.

While the present invention has been described in detail with respect to certain exemplary embodiments, various modifications and alternative embodiments thereof will be apparent to those skilled in the art. The invention encompasses any modifications or alternative embodiments that fall within the scope of the claims.

Claims (10)

1. A separation device for immiscible liquids comprising:

a vessel having an inlet, an inlet chamber, a separation chamber, and an outlet chamber, the inlet feeding effluent into the inlet chamber, the inlet chamber communicating with the separation chamber through a first passageway, the separation chamber communicating with the outlet chamber through a second passageway;

a filter basket having at least one tapered side disposed in the inlet chamber below the inlet with the one tapered side disposed at an angle relative to an adjacent side wall of the inlet chamber.

2. The separation device of claim 1, further comprising a baffle disposed on the filter basket such that the baffle is disposed adjacent the inlet and effluent entering through the inlet is deflected away from the baffle into the filter basket.

3. The separation device of claim 1, further comprising first and second side flanges located on opposite sides of the filter basket to seat against respective first and second support flanges provided in the inlet chamber to hold the filter basket in place, wherein the first side flange and the first support flange have a first width and the second side flange and the second support flange have a second width greater than the first width.

4. The separator arrangement of claim 1 further comprising an oil/grease outlet valve replaceably disposed in one of a plurality of valve housings connected to said separator chamber, said valve having an interlocking connection with the valve housing.

5. The separator arrangement of claim 1 further comprising an auto-closing debris valve disposed adjacent the lower surface of the vessel for removing debris when opened.

6. The separation device of claim 1, further comprising a flexible hollow conduit disposed around the bottom of the container to form a seal with the floor to prevent liquid from leaking under the container.

7. The separation device of claim 1, further comprising:

an upper control panel; and

a valve is disposed through the upper control plate for passing low density fluid over the control plate for removal.

8. The separation device of claim 7, wherein the valve comprises an actuator responsive to a sensor to open and close the valve, the sensor being capable of sensing the level of high density fluid in the separation chamber.

9. The separation device of claim 7, further comprising:

a heater disposed through the upper control plate;

the heater, valve and low density fluid to be removed are thus accessible through a cover on the top of the housing.

10. The separation device of claim 9, further comprising a removable storage container for storing the low density fluid from the valve.