GB2427879A

GB2427879A - Vacuum sewage apparatus

Info

Publication number: GB2427879A
Application number: GB0513580A
Authority: GB
Inventors: Martin Hugh Roche; Joseph Charles Edmunds; Paul Bernard Parker
Original assignee: Rockbourne Environmental Ltd
Current assignee: Rockbourne Environmental Ltd
Priority date: 2005-07-04
Filing date: 2005-07-04
Publication date: 2007-01-10
Also published as: GB0513580D0

Abstract

A collection chamber 1 for a vacuum wastewater/sewage apparatus, the chamber 1 comprises a unitary body 2 defining a main chamber, a top 3 and a bottom 4 and an inlet 17 for waste intermediate the top 3 and the bottom 4, the lowermost portion of the main chamber providing sump means 19 for the collection of waste to be discharged therefrom, an outlet 20 for waste held in the sump 19 being provided adjacent or proximate the bottom 4 and a suction pipe 22 communicating with the outlet 20 and extending into a sealed or sealable chamber 6 located in the main chamber in which an interface valve 10 is held.

Description

SEWAGE

This invention relates to sewage and to means of collecting sewage and waste water from a site.

Vacuum sewers were first used in Europe in 1882 but have recently become more commonplace in a variety of installations They have found particular utility in rural communities, new housing developments, old towns with narrow streets to name a few.

In brief, a vacuum sewage collection system comprises a collection chamber, vacuum sewers and a vacuum station.

The collection chamber is connected to, for example, a house, by conventional gravity fed drains. It has two purposes. Firstly, it collects the wastewater discharged from the house in a sump and secondly it allows the collected wastewater effluent to enter the sewer network via an interface valve, also known as the vacuum valve. I. II

Within the collection chamber, as the level of the wastewater within the wet sump rises, (IIf I air is trapped in a pipe called a sensor pipe', the pressure of which increases as the effluent level continues to rise. This increase in air pressure is subsequently transferred via flexible tubing to the controller' that is fixed to the interface valve Eventually this pressure becomes great enough to operate a switch within the controller which then allows vacuum pressure to be transferred to the main body of the valve and cause it to open.

With the valve in the open position, air at atmospheric pressure acting on the surface of the liquid within the wet sump then forces the waste water into the suction pipe', past the interface valve and onward into the vacuum sewer network.

Once all of the sewage has been removed from the wet sump, the valve remains open for a short period of time to allow air at atmospheric pressure to enter the vacuum network.

The valve then closes under the action of a spring to complete one cycle.

The vacuum sewers form a pipe network through which a vacuum is transferred to the interface valve and along which the wastewater/effluent is transported to the vacuum station The pipes are usually laid in a saw-tooth profile and consist of plastics pipes * having a diameter of from 90 to 250 mm. ** **,

* * 1 3 Typically the wastewater/sewage will initially travel as a foam plug' at velocities of up *. to about 6 ms1. The velocity gradually reduces as the aliquot of effluent moves along the pipes towards the vacuum station.

S... I I * I Finally, the sewage reaches the vacuum station, which is the third element of the system.

The main items of equipment within the vacuum station are vacuum pumps, a collection vessel, sewage discharge pumps and an electrical control panel.

The vacuum pumps are connected to the collection vessel which acts as the wet sump normally found within a conventional gravity pumping station.

Rising wastewater levels within this collection vessel are detected by level probes which initiate the operation of sewage discharge pumps connected via pipework to the vessel.

These pumps remove the collected wastewater from within the vessel and forward it to the local sewage treatment plant or nearby main sewer In conventional collection chambers, the suction pipe and the sensor pipe extend into the sump with either the valve above the wastewater. This can cause a problem with matter becoming adhered to the pipes, for example toilet paper, a problem known as rag-up' or ragging' A further problem can occur if the sump overfills. This can cause flooding of, and L:' damage to or blocking of, the valve. S... * 15 S...

One proposed solution is to be found in US 5510715 which discloses a float valve for *. the sump to close a passage to the valve once the sewage has reached a pre- determined level. However, it will be appreciated that float valves will take up valuable S.....

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space themselves and are susceptible to fault and so cannot be considered a complete solution.

The problem of valve flooding can also lead to complications when the valve is to be maintained or replaced as the engineer will have to clean the outside of the valve before he can perform the maintenance operation An alternative design is to have a wet sump with external pipes and a separate valve chamber' This takes up a larger area and also has more complex pipework and ducts than a single chamber.

Clearly, there is a need to provide apparatus which can address these problems.

Accordingly, one or more of the foregoing problems are addressed by a collection chamber of the current invention.

A first aspect of the invention provides a collection chamber for a vacuum wastewater/sewage apparatus, the chamber comprising a unitary body defining a main chamber, a top and a bottom and an outlet intermediate, the top and bottom for the ingress of waste, the lowermost section of the main chamber providing sump means for L: the collection of waste to be discharged therefrom and the body having located therein S...

a sealed or sealable chamber which houses an interface valve, the body having closure means at or adjacent the top through which the main chamber and the sealable :. chamber are accessible.

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A second aspect of the invention provides a collection chamber for a vacuum wastewater/sewage apparatus, the chamber comprising a unitary body defining a main chamber, a top and a bottom and an inlet for waste intermediate the top and the bottom, the lowermost portion of the main chamber providing sump means for the collection of waste to be discharged therefrom, an outlet for waste held in the sump being provided adjacent or proximate the bottom and a suction pipe communicating with the outlet through which waste is removable from said sump means.

There is further provided in a third aspect of the invention a collection chamber for a vacuum wastewater!sewage apparatus, the chamber comprising a unitary body defining a main chamber, a top and a bottom and an inlet for waste intermediate the top and the bottom, the lowermost portion of the main chamber providing sump means for the collection of waste to be discharged therefrom, an outlet for waste held in the sump being provided adjacent or proximate the bottom and a suction pipe communicating with the outlet and extending into a sealed or sealable chamber located in the main chamber in which an interface valve is held.

The, or a, suction pipe may have a constriction downstream of the, or a, outlet to prevent oversize solids passing therealong.

Preferably, a sensor pipe communicates with the suction pipe at a position downstream of the outlet S.. S

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A further aspect of the invention provides a collection chamber for a vacuum wastewater/sewage apparatus, the chamber comprising a unitary body defining a main chamber, a top and a bottom and an inlet for waste intermediate the top and the *SS.. S bottom, the lowermost portion of the main chamber providing sump means for the collection of waste to be discharged therefrom, a suction pipe communicating with said sump means through which waste is removable from said sump means and a sensor pipe, wherein the sensor pipe communicates with the suction pipe The sensor pipe preferably extends into a, or the, sealed or sealable chamber which houses a, or the, interface valve.

Preferably the, or a, sealed or sealable chamber housing the, or an, interface valve is located above the inlet.

The, or a, sealed or sealable chamber may be sealed or sealable using a removable closure, for example a threaded closure to engage a threaded portion in the sealed or sealable chamber.

The main chamber is preferably accessed through an access cover.

A grid or mesh may be provided below the, or a, access cover to prevent, or at least inhibit, articles from falling into the main chamber.

The main chamber may comprise a storage portion arranged to store overflow from the : sump means.

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The main body is preferably formed of a plastics material, for example double laminated, corrosion resistant, high density polyethylene. * S

* *.: A further aspect of the invention provides a method of making a collection chamber, the method comprising: a) forming a unitary body having a top and a bottom and an inlet therebetween for the ingress of waste, a lowermost section to provide sump means and an outlet for the discharge of waste from said sump means; b) connecting a suction pipe to said outlet, c) installing the collection chamber in a site.

A yet further aspect of the invention provides a method of making a collection chamber, the method comprising a) forming a unitary body having a top and a bottom and an inlet therebetween for the ingress of waste and a lowermost section to provide sump means; b) forming a pipe assembly comprising a suction pipe and a sensor pipe, wherein the sensor pipe communicates with the suction pipe; and c) installing or connecting the pipe assembly in or to the unitary body.

The pipes of the pipe assembly may be installed in or connected to the unitary body either before or after the suction pipe and sensor pipe communicate.

The unitary body may be formed by rotational moulding.

The unitary body maybe surrounded by a second body to provide a composite, double

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skinned body. *S * * * a..

*. In order that the invention may be more fully understood, it will now be described by : * way of example only and with reference to the accompanying drawings, in which.

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Figure 1A is a plan view of a collection chamber according to the invention; Figure lB is a sectional view along line A-A of Figure 1A; and Figure 1C is a sectional view along line B-B of Figure 1A.

Referring to the drawings, there is shown a collection chamber 1 for a vacuum wastewater/sewage system. The collection chamber 1 provides a collection chamber for wastewater emitted from a site, such as one or more houses and an interface between the house and the vacuum system and subsequent wastewater processing apparatus.

The collection chamber 1 is formed with a unitary body 2 which has a top 3 and a bottom 4 The body 2 is conveniently considered in three sections, an upper section 5A, intermediate section 5B and lower section 50.

The upper section 5A is of generally frusto-conical form, and is internally divided into two compartments, a valve compartment 6 and an access compartment 7 each provided with a removeable closure 8, 9 respectively The valve compartment 6 is sealed and contains therein an interface valve 10, chamber monitoring module 11, the service connection 12 as well as the terminal ends of a suction pipe 13 and sensor pipe 14 In accordance with standard practice, the suction pipe 13 is operably connected to, and communicates with, the interface valve and the sensor pipe 14 is operably connected to the interface valve 10. *S.

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The suction pipe 13 and sensor pipe 14 extend through the lowermost wall of the sealed valve compartment 6 and are sealed therein using conventional water-tight seal means such as grommets, 0-rings, silicone sealant and the like.

The output from the interface valve 10 and service connection 12 extends through the lowermost wall of the valve compartment 6 to provide an outlet 15 for connection to the sewage pipe (not shown).

The access compartment 7 has a screen 16 defining its lower extent which is removeable but which prevents detritus from falling further into the body 2 The intermediate section 5B is of generally C-shaped form (along a horizontal section) to define a vertical axially extending mouth 16 along which the suction pipe 13, sensor pipe 14 extend and from which the vacuum sewer pipe (not shown) extends.

An inlet for waste 17 from a site is provided in the wall of the unitary body 2 at a point towards the upper part of the intermediate section 5B As will be explained below, the intermediate section 5B provides emergency wastewater storage. To monitor wastewater storage in this section 5B a float valve 18 depends thereinto which is operably connected to the chamber monitoring module 11 Typically the usable volume of the intermediate section 5B (the usable volume being the volume from the bottom of the section 5B to the lowermost part of the inlet 17) is . about 2201 per serviced site * .

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* The lowermost section 5C provides the principal waste storage zone 19 (usually called :. a batch sump). It is of conical form and has an outlet 20 adjacent its bottom 21 which communicates with the proximal end of the suction pipe 13. The bottom 21 is angled * :...: so that it tilts towards the outlet to ensure maximum waste egression.

The storage zone 19 will typically have a useable volume of 30U per batch.

The suction pipe 13, which extends from the outlet 20 through the mouth 16 and into the valve compartment 6 is provided with a restriction 22 at a point downstream of the outlet to prevent oversized particles or agglomerates from being drawn into the pipe 13 and thereby reducing the risk of the pipe 13 or (more importantly) the interface valve 10 becoming blocked The sensor pipe 14 communicates with the suction pipe 13 as a T junction off the suction pipe 13. As the wastewater level in the waste storage zone 19 rises the level in the sensor pipe also rises, thereby compressing the air above to provide a positive pressure for (after suitable compression) actuation of the controller of the interface valve 10 Upon activation, the interface valve 10 opens and the rush of wastewater up the suction pipe 13 causes a venturi effect in the sensor pipe 14 drawing the water from the sensor pipe 14 with a vigorous cleansing action for self cleansing of the sensor pipe 14 each batch This prevents the build up of fats and greases in the sensor pipe 14 which can be problematic.

To form the collection chamber 1 the walls 2A, 2B are rotationally moulded from plastics material for example high density erosion resistant polyethylene. Protective .: layers may be sprayed or otherwise applied to the walls of the body 2. S..

It is possible to form the sealed valve compartment 6 integrally although it may be as * convenient to form it as a separate item and then install it within the upper section 5A of the body 2.

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The body is formed with apertures to provide the inlet 17, the outlet 20 and to accept the ends of the suction 13 and sensor 14 pipes.

The suction 13 and sensor 14 pipes are then installed and are sealed in place using conventional seal means (not shown). The components of the valve compartment 6 are then installed A connection for the sewage pipe (not shown) is provided to connect to the outlet 15.

If further protection is required the mouth 16 can be back-filled with foam to protect the suction 13 and sensor 14 pipes as well as the sewage outlet 15 and connection for the sewage pipe (not shown). Foam may be used to cover and surround all exposed parts of the suction 13 and sensor 14 pipes to afford protection thereto or concrete can be used when installing the collection chamber in the ground.

In this way the valve chamber 1 can be factory constructed, transported to a site and then lowered into the site In order to render the chamber 1 operative, the inlet 17 and sewage pipes need be connected only. The volume surrounding the chamber 1 is then filled with concrete to a minimum thickness of 150 mm.

Once installed, the cable for the valve and sump monitoring may be connected and a conventional access cover 30 may be located to allow access to the chamber 1 (note: L:' * non electric operation, just a low voltage cable for the monitoring system) a a..

In operation, waste from a site enters the chamber 1 via the inlet 17 and collects in the * * storage zone 19. The level of waste located in the storage zone 19 is monitored by the * sensor pipe 14 which, when a predetermined level has been reached, exerts an a..... * a

* : ** activating pressure on the interface valve 10, causing it to open and expose the suction pipe 13 to the vacuum in the vacuum sewage pipes. The atmospheric pressure in the chamber 1 forces the waste in the collection zone 19 into the suction pipe 13 and from there into the vacuum sewage network and on to treatment.

Typically, the interface valve 10 will remain open for a number of seconds, sayS to 15 seconds to effect complete evacuation of the collection zone 19. As the collection zone 19 is empty the sensor pipe 14 is reset and the process can start again The air to liquid ratio within the chamber 1 is chosen so that the sewers are not flooded with wastewater and that there is sufficient air capacity in the sewers to enable a vacuum to be drawn We have found that a ratio of between 3:1 and 121, preferably 6. 1 air-to- liquid is suitable, although other ratios may also be used.

In normal operation the sensor pipe 14 is cleaned as the waste is pushed into the suction pipe 13 as explained above If, for any reason, the waste is not evacuated from the collection zone 19 waste will start to collect in the emergency waste storage provided by the intermediate zone 5B.

As waste rises in the intermediate zone 5B it will at some point start to actuate the float valve 18. This will be monitored by the chamber monitoring module 11 which can be arranged to inter a/ia automatically open the interface valve 10 and/or record that a : fault has occurred and/or to send a signal to a remote monitoring station that I..

.5 maintenance may be required a * * * a..

*. The float valve 18 is above the lowermost part of the intermediate section 5B to allow for surges in waste which are not immediately evacuated from the collection zone 19. * a

a.... I * * If an engineer is required to inspect the chamber 1 he simply needs to remove the access cover 30 and then one or both of the closures 18, 19. If the module 11 is fully automated and able to run diagnostic programs a signal will or may have been sent to the engineer and he will have foreknowledge of the problem. In which case he need only access the appropriate part of the chamber 1.

For example, if there is a problem with the interface valve 10 the engineer need only access the valve compartment 6. It will further be appreciated that suction and/or positive pressure can be applied to the suction pipe 13 by disconnecting the interface valve 10 and connecting pipes to the terminal end of the suction pipe 13.

If it is required to access the collection zone then this can be done in isolation, without the need to remove the interface valve 10 or the valve 10 obstructing the passage.

It will be further appreciated that because the suction 13 and sensor 14 pipes are without the collection zone 19 there is no opportunity for material to become adhered to those pipes Also, because the chamber 1 can be constructed in a factory installation, time on site is reduced, leading to a concomitant reduction in installation costs The overall footprint is small so less problems installing in roads and footpaths with 0Ip S numerous utilities that could be problematic. I' * q * *iS

Gravity sewers from house can be connected at any line or level to suit the collection chamber dimensions and sealed using grommets etc. S...., * 0 The discharge pipe can be set on site to the required level.

The volume of either the intermediate section 5B or the sump 5C will be chosen as appropriate the regulations in the country in which the chamber 1 is to be installed and the particular operating conditions (e.g. the water company design flows and loads).

Claims

Claims 1. A collection chamber for a vacuum wastewater/sewage apparatus,

the chamber comprising a unitary body defining a main chamber, a top and a bottom and an inlet for waste intermediate the top and the bottom, the lowermost portion of the main chamber providing sump means for the collection of waste to be discharged therefrom, an outlet for waste held in the sump being provided adjacent or proximate the bottom and a suction pipe communicating with the outlet and extending into a sealed or sealable chamber located in the main chamber in which an interface valve is held.
2 A collection chamber for a vacuum wastewater/sewage apparatus, the chamber : * comprising a unitary body defining a main chamber, a top and a bottom and an inlet for waste intermediate the top and the bottom, the lowermost portion of the main chamber providing sump means for the collection of waste to be discharged therefrom, an outlet for waste held in the sump being provided S.....

adjacent or proximate the bottom and a suction pipe communicating with the outlet through which waste is removable from said sump means.

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3. A collection chamber for a vacuum wastewater/sewage apparatus, the chamber comprising a unitary body defining a main chamber, a top and a bottom and an intlet intermediate the top and bottom for the ingress of waste, the lowermost section of the main chamber providing sump means for the collection of waste to be discharged therefrom and the body having located therein a sealed or sealable chamber which houses an interface valve, the body having closure means at or adjacent the top through which the main chamber and the sealable chamber are accessible.
4. A chamber according to Claim 3, further comprising a suction pipe communicating with said outlet and providing a conduit between said outlet and said interface valve.
A chamber according to Claim 1, 2 or 4, wherein the suction pipe has a constriction downstream of the outlet to prevent oversize solids passing therealong.
6. A chamber according to Claim 1, 2, 4 or 5, wherein a sensor pipe * communicates with the suction pipe at a position downstream of the outlet. S... * S * 555
7. A chamber according to Claim 6, wherein the sensor pipe extends into a, or the, S... * .

* S sealed or sealable chamber which houses a, or the, interface valve.

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8 A chamber according to any preceding Claim, wherein the, or a, sealed or *S55SS * sealable chamber housing the, or an, interface valve is located above the inlet.
9. A chamber according to any preceding Claim, wherein the, or a, sealed or sealable chamber is sealed or sealable using a removable closure.
A chamber according to Claim 9, wherein the removable closure is a threaded closure to engage a threaded portion in the sealed or sealable chamber.
11 A chamber according to any preceding Claim, wherein the main chamber is accessed or accessable through an access cover.
12 A chamber according to any preceding Claim, further comprising a grid or mesh provided below the, or a, access cover to prevent, or at least inhibit, articles from falling into the main chamber.
13. A chamber according to any preceding Claim, wherein the main chamber comprises a storage portion arranged, in use, to store overflow from the sump means.
14. A chamber according to any preceding Claim, wherein the main body is formed of a plastics material. I... * S S...
15. A chamber according to any preceding Claim, wherein the plastics material is S...

double laminated, corrosion resistant, high density polyethylene.

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16. A method of making a collection chamber, the method comprising: S.....

* a) forming a unitary body having a top and a bottom and an inlet therebetween for the ingress of waste, a lowermost section to provide sump means and an outlet for the discharge of waste from said sump means; b) connecting a suction pipe to said outlet; c) installing the collection chamber in a site.
17. A method of making a collection chamber, the method comprising: a) forming a unitary body having a top and a bottom and an inlet therebetween for the ingress of waste and a lowermost section to provide sump means; b) forming a pipe assembly comprising a suction pipe and a sensor pipe, wherein the sensor pipe communicates with the suction pipe; and c) installing or connecting the pipe assembly in or to the unitary body.
18. A method according to Claim 17, comprising installing or connecting the pipes of the pipe assembly in or to the unitary body either before or after the suction pipe and sensor pipe are arranged to communicate.

19 A method according to any of Claims 16 to 18, comprising forming the unitary body by rotational moulding. * S.. * . *SSS

20 A chamber as hereinbefore described, with reference to the Figures. *.. . * . S.

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21 A method as hereinbefore described. * S * S..

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