US2453219A - Grease interceptor - Google Patents

Description

Nov. 9, 1948.

INVENTOR. STANLEY J-GRUM.

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s. 'GRUM GREASE INTERCEPTOR Filed July 19, 1945 Patented Nov. 9, 1948 GREASE INTERCEPTOR Stanley J. Grum, Michigan City, Ind., assignor to Josam Manufacturing Company, Cleveland, Ohio, a corporation of Delaware Application July 19, 1945, Serial No. 605,945

The present invention relates to an improved grease interceptor of the type comprising a closed top intercepting chamber into which waste water is directed for causing separation of grease and other light weight Waste materials from the Water in the chamber, the clarified water being discharged from the chamber through a passage leading from the bottom of the chamber upwardly to a sewer connection located at the normal water level in the chamber.

Heretofore, it has been a practice to provide an air relief passage between the area over the waterin the chamber and the outlet passage of the chamber, which relief passage had its inlet at the top of the chamber and its outlet in the chamber outlet passage slightly below the normal static water level of the chamber. This arrangement enabled air to escape from the area above the Water level when the Water level was raised by incoming waste water. By locating the outlet of the air passage below the water level in the interceptor outlet, an effective seal or trap was provided for preventing sewer gases from entering the intercepting chamber through the air relief passage.

This'arrangement was not satisfactory, however, because there was considerable resistance to the escape of air through the relief passage due to friction in the passage and, principally because the water head over the outlet of the relief passage would increase considerably during surges of waste water into the interceptor. The result was that pneumatic pressure developed above the liquid in the chamber and this pressure depressed the water level below the normal static level and caused a surge of water to discharge from the interceptor, thereby lowering the static water level below that for which the interceptor was designed. This reduction in the normal static level decreased the capacity and efficiency of the interceptor.

An object of the present invention is to provide a grease interceptor of the type described in which the air relief passage has its outlet in the low pressure area of the vena contracta of the water stream formed in the outlet passage of the interceptor and below the liquid level in the latter outlet.

Reduction in back pressure to air release is also efiected by shaping the trap outlet easement to the sewer so that friction to water flow is reduced to a minimum, thereby requiring less lead to induce flow. Thus, the increase in pressure over the liquid will be minimized during surges of waste Water into the interceptor by the relief of 1 Claim. (01. 182-9) air from the interceptor and by the ready fiow of the liquid from the interceptor.

Other objects and advantages of the invention will be apparent from the following description of a preferred form of embodiment of the invention, reference being had to the accompanying drawing wherein:

Fig. 1 is a view in section of a grease interceptor embodying my invention; and 1 Fig. 2 is a fragmentary view in section, the section being taken on line 22 of Fig. 1.

Referring to the drawings, I have shown a grease interceptor indicated generally at 5, which interceptor is adapted to be connected in the drain of a sink or the like, from which water, laden with grease and other light weight waste material, is discharged. The interceptor removes light Weight Waste materials from the waste Water and discharges the clarified Water into a sewage system, for example. Although the invention may be embodied in different forms of interceptors, for the purposes of illustrating the invention, the interceptor 5 comprises a cubical intercepting chamber 6, which may be formed of iron or steel, and having an inlet connection 1 formed in the end wall 8 for connecting the cham-- ber with the drain pipe of a sink, or other source of grease laden water. The outlet of the chamber 6 is formed at the end opposite the inlet, and comprises a pocket or offset 9 communicating with the chamber through an opening ID at the bottom of the end wall I l. A vertically extending tube l2 leads from the pocket 9 upwardly to a horizontally extending sewer connection I l. The pocket 9 and the tube l2 form a trap leg through which water from the lower portion of the chamber 6 may be discharged into a sewer system. The static water level in the chamber is indicated by the line A, and this level obtains during the time no water is discharged into the interceptor. During flow of water into the chamber 6, the level will be above the static level.

Means is provided in the conduit l2 for forming an orifice effect so that a low pressure area is created in the conduit by the flow of water therethrough, the purpose of which will appear hereinafter. Preferably, this means comprises a ring-like flange structure l5 which projects inwardly from the walls of the conduit I2 for forming a restricted opening l9 through which the discharge water passes. This structure 15 is located slightly below the opening outlet of the connection l4 so that it lies below the static liquid level in the interceptor.

In the interceptor shown, the action of the water in the chamber is controlled by two sets of cascades I6, only one set appearing in the drawings, formed in the bottom wall of the chamber and separated by a channel I1, and baffles [8 extending transversely of the chamber. This construction facilitates the separation of the light weight materials ,from the Waste water, but other suitable arrangements may be utilized for'this purpose.

The top of the chamber 6 is adapted to be closed by a removable cover plate 20 which is secured over the chamber by a turned over edge f2l-engaging a flange 22 extending along the upp redge of wall 6, and a wing nut '25 lthreadedon albolt 24 extending from the chamber walls and through an opening in the cover plate. Preferably, a gasket 25 is interposed between thecover plate 20 and the upper edges of the chamber walls for forming an air-tight seal between the Walls and .the cover plate.

'To relieve the air from the area above the water level in the chamber 5 during theinflow of waste water, I have provided an air relief passage extending between the top portion of the chamber and the outlet tube 12. The outlet 30 ofthe air relief passage islocatedlin the wall H .at the top of the chamber 20 so that it will always be above the normal water levels in the chamber. From the inlet 30 the air passageis formed by a downwardly extending conduit 3|, which conduit has an outlet 32 opening into conduit l.2 immediately above the neck-like structure l5. It will be apparent that as the clarified water flows through tube 12 .to the sewer connection M, a vena contracta eifect will be created at th structure [5 and a low pressure area will exist at the outlet 32 of the airrelief passage, Thus, movement of air through the relief passage will be induced by the flow of water through tube I2 and there will be no pressure over the liquid in the chamber to cause surging and lowering of the liquid level in the chamber. Furthermore, since the outlet 32 of the air relief passage is below the static water :level, the passage is sealed against the entrance of sewergases.

able pressures above the liquid in the chamber and at the same time, an effective seal is provided against the entrance of sewer gas into the air relief passage and intercepting chamber. By my invention; surging of the liquid in the interceptor is .obviated and full eihciency of the interceptor is maintained.

Although I havedescribed but one form of the invention, other forms might be adopted, all falling within the scope of the claim which follows.

I claim:

In a grease interceptor, a closed chamber adapted to receive grease-ladened water said chamber having an outlet comprising a conduit,

circular in cross section, leading from adjacent the bottom of the chamber to an opening .dis- 'posed below the top of the chamber whereby'a body of liquid is maintained inthe chamber; .a

ring like formation projecting inwardly from the walls of the conduit below said opening an'd'iorming a constriction in said conduit; and means forming an air relief passage interconnecting said chamber andconduit, said passage"havingfits'inlet disposed in said chamber above the liquidlevel therein and its outlet disposed immediately above said ring like member iandbelow said opening.

STANLEY J. GRUM.

REFERENCES crimp The following references are of -recordin the "file of this patent:

UNITED 'STA'I'ES PATENTS .Number Name Date 2,268,854 Boosey Jan 6, 1942 2,272,912 Heinkel .Feb. 10,1942 2,284,737 Hirshstein June -2, 1942 2,345,787 Boosey .Apr. 4,, 1944:

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