Patent Description:
The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.

Wastewater systems, including sewage systems, are inherently affected by the presence of unwanted pressurized air in pipelines that can result in operational problems such as broken pumps, valves and pipes. In order to minimise these problems, air release valves (ARVs) are located at the highpoints of pressurised pipelines to de-aerate the pipelines and relieve any excess pressure.

An ARV typically includes a receptacle engaged with the pipeline to receive pressurized air and wastewater. A float valve is fitted to the receptacle and releases air in the receptacle as pipeline pressure increases. The float valve also permits the ingress of air into the receptacle as pipeline pressure decreases. The float valve further includes a float which rises with the wastewater level in the receptacle, to close the valve and thereby prevent wastewater from exiting the ARV.

International patent application <CIT> discloses a valve for a vessel, into which a liquid is filled, and from which a liquid is drained off, with a float that has substantially the form of a cylindrical tube sealed at one end, that can move back and forth, along its axis, between an open and closed position in a coaxial cylindrical chamber of a housing whose internal diameter is slightly larger than that of the external wall of the tube, so that a passageway with a ring-shaped cross section is formed between the external wall of the tube and the internal wall of this chamber, whereby the closed end of this tube, in said closed position, closes the inlet and outlet opening provided in the latter, and the opposite open end is located opposite a distribution device for said liquid, that during the filling of the vessel with liquid, prevents the latter from flowing directly into the cavity inside the float, thus ensuring that a bubble of gas is always present inside it.

Japanese patent application <CIT> discloses an air valve that guides lifting and lowering of a idling valve body and a float valve body with a guide cylinder member, that lifts the floating valve body via the float valve body with water flowed from a small opening formed at a bottom of the guide cylinder member into the guide cylinder member, and brings the idling valve body in contact with a valve seat around a big air hole in a valve box having the big air hole communicating with a communicating passage and discharging air at an lower end to close. Between the valve box and the guide cylinder member, a circumferential strainer for removing the foreign substance in fluid flowing from the communicating hole into a communicating hole is provided. The strainer is comprised of a capturing cylinder made of metal in which many openings are formed, and caps and installed along a edge of the capturing cylinder coming in contact with the valve box and the guide cylinder member.

British patent application <CIT> discloses a valve for releasing gas from a liquid container comprising a float which co-operates with an orifice in an upper chamber of a housing is provided with a second float in a lower chamber communicating with the upper chamber which second float is normally held away from a valve seat but which on dismantling of the upper part of the housing automatically closes against the valve seat so that inspection can be carried out without leakage from the container.

Patent application <CIT> discloses a valve according to the preamble of claim <NUM>.

In practice, wastewater flotsam builds up within the receptacle over time and can have a detrimental effect on the operation of the ARV. Accordingly, it is often necessary to periodically clean the interior of the receptacle from flotsam which can be an arduous task. Furthermore, wastewater flotsam can clog up the float valve and thereby render the ARV ineffectual.

Furthermore, the float is often in the form of a sealed ball which can implode or burst in the event of excess pressure in the receptacle, thereby also hindering the performance of the ARV.

Embodiments of the present invention provide a wastewater valve arrangement for impeding clogging of the valve with flotsam.

Embodiments of the present invention provide a wastewater valve arrangement having an implosion resistant float.

According to a first aspect of the present invention, there is provided a wastewater valve arrangement according to claim <NUM>.

Preferably, the valve means is configured to permit the release and ingress of air relative to the second receptacle. Typically, the valve means is configured to be normally open. The valve means may include a float that defines a recess.

The filter may include an endless mesh wall. The filter may further include an inlet tube which extends from the mesh wall. The inlet tube may have a lesser cross sectional area than a portion of the mesh wall. The filter may further include a handle mounted to the mesh wall.

The first lid may be fitted to the first receptacle in air tight engagement using an O-ring.

The upper end of the first receptacle forms a compression chamber in which air can be compressed.

The second lid defines an aperture through which the valve means extends when fitted.

The receptacles are interconnected by a pair of connection tubes. The connection tubes may be spaced apart and parallel. Alternatively, the tubes may divergently extend from the first receptacle.

According to a second aspect of the present invention, there is provided a wastewater system comprising a wastewater valve arrangement according to the first aspect.

Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of the Invention in any way. The Detailed Description will make reference to the drawing as follows:.

According to an embodiment of the present invention, there is provided a wastewater air release valve ARV <NUM> shown in <FIG> which is suitable for fitting to the pipeline <NUM> of a sewage system. The ARV <NUM> includes a filtration receptacle <NUM> for receiving a removable filter <NUM> to filter wastewater. A valve receptacle <NUM> is provided for receiving the filtered wastewater from the filtration receptacle <NUM>. The ARV <NUM> further includes a float valve <NUM> which is fitted to the valve receptacle <NUM>. The float valve <NUM> permits the release and ingress of air relative to the valve receptacle <NUM>, and impedes the egress of filtered wastewater from the valve receptacle <NUM>. A detailed description of the ARV <NUM> is provided in detail below.

The filtration receptacle <NUM> includes a container <NUM> to which a lid <NUM> can be fitted in air tight engagement using an O-ring (not shown). The lid <NUM> is releasably fastened to the container <NUM> using fasteners <NUM> that take the form of nut and bolt arrangements. A handle <NUM> is mounted to the lid <NUM> to facilitate hand separation of the lid <NUM> from the container <NUM>. The base of the container <NUM> defines a throat from which a flange extends. The flange can be mounted to the pipeline <NUM> using fasteners <NUM> so that the throat of the container <NUM> is in register with an aperture <NUM> defined in the pipeline <NUM>.

The ARV <NUM> further includes the filter <NUM> which, in turn, includes an endless mesh wall <NUM>. The filter <NUM> further includes a solid inlet tube <NUM> which extends from the base of the mesh wall <NUM>. The base of the mesh wall <NUM> also defines a throat so that the inlet tube <NUM> has a lesser cross sectional area than the upper end of the mesh wall <NUM>. The filter <NUM> further includes a handle <NUM> mounted to the top of the mesh wall <NUM> to facilitate hand removal of the filter <NUM> from the container <NUM>.

A pair of open connection tubes 32a,b interconnect the receptacles <NUM>,<NUM> so that fluid can freely pass between them. These two spaced tubes <NUM> provide for a structurally stable ARV <NUM>.

The valve receptacle <NUM> includes a container <NUM> to which a lid <NUM> can be fitted in air tight engagement using an O-ring (not shown). The lid <NUM> is releasably fastened to the container <NUM> using fasteners <NUM> that take the form of complementary nut and bolt arrangements. The lid <NUM> defines a central aperture through which the float valve <NUM> extends when fitted.

The float valve <NUM> includes a float <NUM> at its base that defines an underside recess. In use, wastewater filling the container <NUM> lifts the float <NUM> and thereby traps air in the underside recess. The float is not prone to implosion as there is no significant pressure differential between the air in the underside recess and the air in the container <NUM>.

The float valve <NUM> further includes a bent housing <NUM> in which an annular seat <NUM> is fitted. An arm, extending from the float <NUM>, terminates in an upper stopper that engages with the seat to close the valve <NUM>. The float valve <NUM> is configured to be normally open and closes as the wastewater level rises in the valve receptacle <NUM>.

In use when the pipeline pressure increases, wastewater (i.e. sewage) including flotsam and other debris exits the pipeline <NUM> and enters the filtration receptacle <NUM>. In turn air in the filtration receptacle <NUM> passes through the connection tubes 32a,b, the valve receptacle <NUM> and out through the float valve <NUM>. As the wastewater level in the filtration receptacle <NUM> increases, wastewater passes into the valve receptacle <NUM> via the filter <NUM> and connection tubes 32a,b respectively. Accordingly, flotsam is impeded from entering the valve receptacle <NUM> and remains within the filter <NUM>.

Compressed air is trapped at the top the filtration receptacle <NUM> as the wastewater level rises therein above the connection tube 32a. This compressed air cannot escape as the lid <NUM> is fitted in air tight engagement with the container <NUM>, and facilitates flushing of flotsam back into the pipeline <NUM> when the wastewater level (and pipeline pressure) drops. The wastewater fills the ARV <NUM> at a controlled rate and thereby prevents a shock or water hammer condition from occurring that might otherwise damage the ARV <NUM> or pipeline <NUM>.

As the filtered wastewater level increases above a predetermined threshold within the valve receptacle <NUM>, the valve <NUM> closes as previously described to thereby impede the egress of wastewater from the valve <NUM>. As the pipeline pressure drops with decreasing wastewater level, the valve <NUM> opens once more to permit the ingress of fresh air into the ARV <NUM>.

Periodically, the user can clean the ARV <NUM> of collected wastewater flotsam. The lid <NUM> is unfastened from the container <NUM> and removed using the lid handle <NUM>. In turn, the user can readily remove the filter <NUM> from within the container <NUM> using the filter handle <NUM>. In practice, the filter <NUM> holds accumulated flotsam which is prevented from reaching and otherwise clogging the valve <NUM>. Much of the heavier filtered flotsam rests in or upon the base tube <NUM> and can be extricated using a pipe cleaner. The mesh wall <NUM> of the filter <NUM> can be subsequently cleaned using a high pressure hose, and the filter <NUM> can then be returned to the cleaned container <NUM>. The high pressure hose can also be used to clean the interior of the container <NUM> and float valve <NUM> upon removal of the lid <NUM>.

A person skilled in the art will appreciate that many embodiments and variations can be made without departing from the ambit of the present invention.

For example, in one embodiment, compressible hollow rubber balls may be provided within the underside recess of the float <NUM>.

In another embodiment, the throat at the base of the container <NUM> may be fitted with a drain tap through which any excess wastewater in the container <NUM> can be drained during cleaning.

In another embodiment shown in <FIG>, the connection tubes 32a, 32b divergently extend from the filtration receptacle <NUM>. Once again, compressed air is trapped at the top the filtration receptacle <NUM> as the wastewater level <NUM> rises therein above the mouth of connection tube 32a. Compression of the air within receptacle <NUM> in the embodiment of <FIG> occurs sooner than the embodiment of <FIG>.

Claim 1:
A wastewater valve arrangement (<NUM>) including:
a first receptacle (<NUM>) receiving a removable filter (<NUM>) to filter flotsam from wastewater;
the first receptacle (<NUM>) comprising a first container (<NUM>) having a base defining a throat from which a flange extends which flange can be mounted to a wastewater pipeline; and
a second receptacle (<NUM>) comprising a second container (<NUM>) for receiving the filtered wastewater;
characterized in that
a pair of spaced and open connection tubes (32a,b) interconnect the receptacles (<NUM>,<NUM>) so that fluid can freely pass between them;
a first lid (<NUM>) is releasably fastened to the first container (<NUM>) in air tight engagement;
the first receptacle (<NUM>) defines a compression chamber at an upper end in which air can be compressed, the compressed air being trapped at the top the filtration receptacle (<NUM>) as the wastewater level rises therein above the connection tubes (32a,b), wherein this compressed air cannot escape as the lid (<NUM>) is fitted in air tight engagement with the container (<NUM>), and facilitates flushing of flotsam back into the pipeline (<NUM>) when the wastewater level drops;
a second lid (<NUM>) is releasably fastened to the second container (<NUM>) in air tight engagement; and
the wastewater arrangement (<NUM>) includes valve means (<NUM>) for impeding the egress of filtered wastewater from the second receptacle (<NUM>), the second lid (<NUM>) defining an aperture through which the valve means (<NUM>) extends.