GB2038388A - Gully Trap - Google Patents

Abstract

A gulley comprises an external chamber (1) having a cover (2) a side exit (3) and an internal chamber (6) having apertures (8). The cover (2) has apertures (5) overlying the chamber (6) forming an entry to the gulley. The exit (3) is above the level of the apertures (8) so that a liquid seal is formed between the entry to the gulley and its exit. <IMAGE>

Description

SPECIFICATION Gulley This invention relates to a gulley.

To cope with the problem of surface water removal, drainage channels are provided around structures such as buildings and industrial processing units. In locations such as oil refineries and chemical complexes, these surface drainage channels lead to underground sewers which generally lead in turn to effluent treatment systems. The surface water may become contaminated with oil before drainage or, at some point between the surface channels and the effluent treatment system, it may become mixed with water containing oil, acid or other undesirable substances. Noxious and/or explosive vapours may also be present in the sewers.

Thus in order to prevent the escape of such vapours and to provide a safe passage underground for surface water run-off it is common practice to provide gullies. These are generally cast iron fittings, although recently polypropylene gullies have been produced, which contain a liquid seal to prevent the upward flow of vapour while permitting the downward flow of liquid.

Water enters the gullies through a grid plate on the top, passes through a U bend generally formed within the gulley by means of a baffle plate and leaves through an outlet arm. Direct communication between the outward arm and the space immediately below the entry plate is prevented by means of a plug.

From time to time, gullies have to be dismantled for cleaning and the plugs must be removed to permit cleaning rods to enter the outlet arm. On re-assembling the gullies, it is possible for the plugs to be badly fitted or inadvertently omitted with the result that fumes and vapours can by-pass the liquid seal and emerge from the grid plate, thus creating an unpleasant and/or hazardous situation.

We have now designed a gulley in which the liquid seal cannot be by-passed since there is no possibility of direct communication between the outlet arm and the enters.

Thus according to the present invention there is provided a gulley comprising (1) an external chamber having a cover and a side arm forming the exit from the gulley and (2) an internal chamber situated within the external chamber and extending from top to bottom thereof and having a plurality of apertures in its lower portion, the cover of the external chamber having a plurality of apertures in that portion of it which lies over the internal chamber forming an entry to the gulley, the distance of the side arm from the base of the gulley being greater than the height of the tops of the apertures in the inlet chamber so that, in use, a liquid seal may be formed between the entry to the gulley and the exit.

For ease of construction the gulley is preferably cylindrical in construction, i.e., both internal and external chambers being cylindrical.

Both sets of apertures are preferably in the form of slots.

For ease of handling and chemical resistance, the components of the gulley are preferably manufactured from a rigid plastics materials.

Polypropylene is particularly suitable.

Such gullies can be made sufficiently large to cope with the increasing quantities of fire water, i.e., water to extinguish fires, specified by increasingly stringent fire regulations, e.g., 25,000 litres per minute, without becoming so heavy and unwieldy that they can only be handled by specialised lifting equipment. The dimensions of cast iron gullies are, of course, limited by weight considerations.

The invention is illustrated with reference to Figures 1 to 3 of the accompanying drawings wherein Figure 1 is a side elevation, partly in section, of a gulley, Figure 2 is a plan view and Figure 3 is a section on CC.

The gulley comprises an external cylindrical chamber 1 having a cover plate 2 and a side arm 3. The cover plate 2 is secured to the chamber 1 by means of bolts 4 and is provided with a number of slots in the form of a circular grid 5.

Beneath the grid 5 is placed a cylindrical internal chamber 6 having a support member 7 for the grid 5. The lower portion of the chamber 6 contains a number of slots 8.

Drainage water enters the gulley through the grid 5, drops into the internal chamber 6, passes out of the internal chamber through the slots 8, rises up into the external chamber 1 and overflows through the side arm 3. Water is retained within the gulley up to the levei of the side arm 3 to form a seal.

Claims

1. A gulley comprising (1) an external chamber having a cover and a side arm forming the exit from the gulley, and (2) an internal chamber situated within the external chamber and extending from top to bottom thereof and having a plurality of apertures in its lower portion, the cover of the external chamber having a plurality of apertures in that portion of it which lies over the internal chamber forming an entry to the gulley, the distance of the side arm from the base of the gulley being greater than the height of the tops of the apertures in the inlet chamber so that, in use, a liquid seal may be formed between the entry to the gulley and the exit.

2. A gulley according to Claim 1, wherein the internal and external chambers are cylindrical in construction.

3. A gulley according to either of the preceding claims, wherein both sets of apertures are in the form of slots.

4. A gulley as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Gulley This invention relates to a gulley. To cope with the problem of surface water removal, drainage channels are provided around structures such as buildings and industrial processing units. In locations such as oil refineries and chemical complexes, these surface drainage channels lead to underground sewers which generally lead in turn to effluent treatment systems. The surface water may become contaminated with oil before drainage or, at some point between the surface channels and the effluent treatment system, it may become mixed with water containing oil, acid or other undesirable substances. Noxious and/or explosive vapours may also be present in the sewers. Thus in order to prevent the escape of such vapours and to provide a safe passage underground for surface water run-off it is common practice to provide gullies. These are generally cast iron fittings, although recently polypropylene gullies have been produced, which contain a liquid seal to prevent the upward flow of vapour while permitting the downward flow of liquid. Water enters the gullies through a grid plate on the top, passes through a U bend generally formed within the gulley by means of a baffle plate and leaves through an outlet arm. Direct communication between the outward arm and the space immediately below the entry plate is prevented by means of a plug. From time to time, gullies have to be dismantled for cleaning and the plugs must be removed to permit cleaning rods to enter the outlet arm. On re-assembling the gullies, it is possible for the plugs to be badly fitted or inadvertently omitted with the result that fumes and vapours can by-pass the liquid seal and emerge from the grid plate, thus creating an unpleasant and/or hazardous situation. We have now designed a gulley in which the liquid seal cannot be by-passed since there is no possibility of direct communication between the outlet arm and the enters. Thus according to the present invention there is provided a gulley comprising (1) an external chamber having a cover and a side arm forming the exit from the gulley and (2) an internal chamber situated within the external chamber and extending from top to bottom thereof and having a plurality of apertures in its lower portion, the cover of the external chamber having a plurality of apertures in that portion of it which lies over the internal chamber forming an entry to the gulley, the distance of the side arm from the base of the gulley being greater than the height of the tops of the apertures in the inlet chamber so that, in use, a liquid seal may be formed between the entry to the gulley and the exit. For ease of construction the gulley is preferably cylindrical in construction, i.e., both internal and external chambers being cylindrical. Both sets of apertures are preferably in the form of slots. For ease of handling and chemical resistance, the components of the gulley are preferably manufactured from a rigid plastics materials. Polypropylene is particularly suitable. Such gullies can be made sufficiently large to cope with the increasing quantities of fire water, i.e., water to extinguish fires, specified by increasingly stringent fire regulations, e.g., 25,000 litres per minute, without becoming so heavy and unwieldy that they can only be handled by specialised lifting equipment. The dimensions of cast iron gullies are, of course, limited by weight considerations. The invention is illustrated with reference to Figures 1 to 3 of the accompanying drawings wherein Figure 1 is a side elevation, partly in section, of a gulley, Figure 2 is a plan view and Figure 3 is a section on CC. The gulley comprises an external cylindrical chamber 1 having a cover plate 2 and a side arm 3. The cover plate 2 is secured to the chamber 1 by means of bolts 4 and is provided with a number of slots in the form of a circular grid 5. Beneath the grid 5 is placed a cylindrical internal chamber 6 having a support member 7 for the grid 5. The lower portion of the chamber 6 contains a number of slots 8. Drainage water enters the gulley through the grid 5, drops into the internal chamber 6, passes out of the internal chamber through the slots 8, rises up into the external chamber 1 and overflows through the side arm 3. Water is retained within the gulley up to the levei of the side arm 3 to form a seal. Claims

1. A gulley comprising (1) an external chamber having a cover and a side arm forming the exit from the gulley, and (2) an internal chamber situated within the external chamber and extending from top to bottom thereof and having a plurality of apertures in its lower portion, the cover of the external chamber having a plurality of apertures in that portion of it which lies over the internal chamber forming an entry to the gulley, the distance of the side arm from the base of the gulley being greater than the height of the tops of the apertures in the inlet chamber so that, in use, a liquid seal may be formed between the entry to the gulley and the exit.

2. A gulley according to Claim 1, wherein the internal and external chambers are cylindrical in construction.

3. A gulley according to either of the preceding claims, wherein both sets of apertures are in the form of slots.

4. A gulley as hereinbefore described with reference to the accompanying drawings.