GB2070694A - Sewage collection and disposal apparatus - Google Patents

Abstract

Sewage collection and disposal apparatus for passenger vehicles, particularly railway carriages and boats, comprises an enclosed collecting tank 1 carried on the vehicle and having one or more inlet ducts 4 which can be closed automatically or manually when the tank is being emptied. Emptying is effected through an outlet duct 5 to a fixed drainage or disposal system when the vehicle is at a service depot, by pressurising the tank using compressed air or other purging fluid so as to expel its contents, admitted through a non-return valve 12 and a diaphragm actuated pressure responsive valve 13. The latter valve renders the purging system inoperative (e.g. by maintaining venting of the tank to atmosphere and/or cutting off the purging fluid flow) until the diaphragm is acted on by fluid pressure through one or more auxiliary valves 15, 17 whose positioning is interlocked with other components and/or under manual control e.g. to ensure that a hose is correctly connected to the outlet and/ or that the inlet ducts are closed so that the correct operating sequence is ensured. <IMAGE>

Description

SPECIFICATION Sanitary apparatus This invention relates to apparatus for the collection and disposal of sewage and/or other liquid or semi-liquid waste products from vehicles, particularly from railway passenger trains though the invention may have application to aircraft, road vehicles, boats, or other passenger transport means and the term passenger vehicle" is used herein to comprise all the foregoing transport means.

Present Health and Safety requirements in countries which are becoming more environmentally conscious make it necessary to improve upon the present system of sewage disposal from passenger vehicles. Until recently, and in fact, even at the present day, lavatories installed in most passenger trains are flushed whilst the train is in motion and the raw excreta is deposited on the track between the lines. With the advent of high speed trains, the hazard is increased due to the scatter effect of flushing at high speed. It is most desirable, therefore, for the sewage and waster water to be retained on the train in suitable tanks and subsequently removed at a servicing depot whilst the train is stationary.

In this way the sewage can be safely transferred into a main drain for subsequent processing and/or safe disposal to avoid health hazards and pollution.

Pollution from boats is also a cause for current concern, particularly on inland waterways such as the Norfolk Broads where there is substantial pleasure traffic. Many inland waterways prohibit discharge into the water even where chemical closets are used and a simple and speedy means of collection and on-shore disposal, preferably readily operable by the boat users themselves is most desirable.

The object of the invention is to provide a simple, reliable and easily and quickly opera ble collection and disposal apparatus.

According to the invention there is provided sewage collection and disposal apparatus for a vehicle including an enclosed collecting tank for liquid or semi-liquid sewage or other waste products; one or more inlet ducts through which the waste products pass into the tank in service each provided with valve means adapted to prevent back flow from the tank through the inlet duct or ducts at least while the tank is being emptied; a connection for pressurising the tank with air or other purging fluid; an outlet duct communicating with a lower region of the tank through which the contents are discharged as the tank is so pressurised; and a pressure responsive valve in said connection having a closure member displaceable between a first position at which the connection is rendered inoperable and a second position at which the connection is operable to pressurise the tank for emptying, and actuating means to which fluid pressure is applied to urge the member to the second position; said actuating means being connected to the pressure connection upstream of the pressure responsive valve by way of one or more auxiliary valves interlocked with components of the apparatus and/or an associated discharge installation to ensure that said components are correctly positioned or set for emptying the tank before the tank can be so pressurised.

The pressure responsive valve is preferably a diaphragm valve responsive to a low air or other purging fluid pressure and including a poppet valve member of substantial diameter to reduce the likelihood of clogging or blockage. It may operate by closing the connection and/or venting the tank to atmosphere at the first position; conveniently it closes the connection and vents the tank to permit filling at the first position and opens the connection and closes the tank venting at the second position.

The inlet duct valve means may be a manually or fluid pressure actuated valve interconnected with the or one of the auxiliary valves to ensure closure before the emptying operation can commence, or it may be an automatic one-way non-return valve.

Further auxiliary valves may include a manual valve for controlling the emptying cycle and a valve associated with means for connecting a static flexible or other discharge pipe to the discharge duct ensuring that operation can only commence when that connection is properly made.

One practical embodiment of the invention for use with railway passanger trains is now more particularly described with reference to the accompanying drawings wherein: Figure 1 is a side elevation of collection and disposal apparatus for a railway carriage; Figure 2 is a plan view of said apparatus; Figure 3 is a diagram of air connections and valve means of said apparatus while the carriage is in service; and Figure 4 is a like diagram showing the arrangement during discharge.

Each carriage is equipped with an enclosed holding tank 1 and associated connections and valve means, conveniently located beneath the floor and which may be shaped to suit available space though preferably it has a sloping bottom leading to a lowermost sump portion 3 into which opens a rising outlet duct 2. The latter extends through the top of tank 1 and is curved to terminate at a connecting portion 5 to which a flexible discharge hose 6 may be connected.

Waste water and sewage from toilets, washbasins or possibly sinks and/or waste disposal units of a dining car is collected in the tank by gravity through an inlet duct 4 and a back flow preventing valve 7, in this case a manu ally operable valve though an automatic nonreturn valve or an automatic or other pneumatically actuated valve may be used. There may be more than one inlet duct to the tank.

A connection 9 for a compressed air hose 8 is provided adjacent portion 5 leading via a main air line 11 and non-return valve 1 2 to an automatic diaphragm valve 1 3 leading into the upper portion of the tank 1. A vent pipe 19 leads from valve 13.

An auxiliary air line 14, 16, 1 8 leads from connection 9 by way of a manually operable shut-off valve 10, a shut-off valve 1 5 which is urged to a closed position unless displaced by an arm which is contacted when hose 6 is properly connected to portion 5, and a further shut-off valve 17 interconnected to valve 7 so that it is only opened when the latter valve is fully closed to prevent back-flow through inlet 4.

Line 1 8 is connected to an enclosed diaphragm chamber 32 of valve 1 3. The latter, shown in Figs. 3A and B, includes a pair of interconnected poppet valve members 30, 31 linked to the diaphragm and, when no pressure is applied in chamber 32, urged to the position shown in Fig. 3A at which the connection of line 11 to the tank is closed and, the tank is vented to atmosphere through vent pipe 1 9. (Chamber 32 is vented through valve 1 7 in this condition). When even a low pressure is applied in chamber 32 members 30, 31 are displaced to close off vent pipe 1 9 and open line 11 to the tank (Fig. 3B).

In operation while the train is in service waste flows along inlet duct 4 and enters tank 1 via valve 7 which will be open. Air displaced from the tank as the liquid rises is expelled to atmosphere via valve 1 3 and vent pipe 1 9. The tank fills whilst the carriage is on normal passenger carrying runs. When the carriage arrives at a servicing depot, the waste water and sewage is expelled from the tank into a fixed drainage or disposal system by the use of compressed air.

The depot is equipped with a fixed sewage pipeline for conveying the sewage to the disposal system comprising a trunk line and spurs, each of the spurs carries an upright branch pipe fitted with a respective hose 6. In the case of a passenger train, the hoses may be at platform level.

A small bore pipeline system laid alongside the sewage pipeline supplies air under pressure from a central air compressing station and has branches with flexible hoses 8 alongside the sewage connections at platform level.

To empty tank 1 hose 6 is connected (by the operator of the depot), between the sewage collecting branch pipe and outlet portion 5 on the vehicle and air hose 8 is coupled to connection 9. The operator then closes valve 7 by turning its operating wheel clockwise.

The system will not operate until flexible hose 6 has been properly attached, and valve 7 has been closed so opening auxiliary valves 1 5 and 1 7. The auxiliary air line 14, 1 6 and 1 8 is now open from manual valve 10 through to chamber 32 of valve 13. Valve 10 is now opened by the operator and pressurised air is admitted to diaphragm chamber 32. The diaphragm and valve members 30 and 31 are deflected, thus vent pipe 1 9 is closed and air from the line supply via non-return valve 1 2 is passed into the tank. The air pressure exerted on the face of the liquid causes a flow from the tank via duct 2, along portion 5 and then into the disposal system via hose 6.When the tank is empty valve 10 is closed by the operator, valve 1 3 reverts to a de-energised state as in Fig. 3A and the trapped air under pressure is released to atmosphere via vent pipe 19.

Valve 7 is now opened, hoses 6 and 8 disconnected, and the tank is ready for further service.

It is not essential that the pressure responsive diaphragm valve 1 3 operates to open and close main air line 11. It may prevent initiation of emptying until all connections are properly made by keeping the tank vented, thus if purging air is admitted to the tank prematurely it will merely escape through the vent pipe. Alternatively valve 1 3 need not control the tank venting but merely the main air line 11, in which case the tank air vent would be opened and closed by other means, e.g. a further valve connected to operate with any of the valves 7, 10, 15 or 17.

Claims (11)

1. Sewage collection and disposal apparatus for a vehicle including an enclosed collecting tank for liquid or semi-liquid sewage or other waste products; one or more inlet ducts through which the waste products pass into the tank in service each provided with valve means adapted to prevent back flow from the tank through the inlet duct or ducts at least while the tank is being emptied; a connection for pressurising the tank with air or other purging fluid; an outlet duct communicating with a lower region of the tank through which the contents are discharged as the tank is so pressurised; and a pressure responsive valve in said connection having a closure member displaceable betwen a first position at which the connection is rendered inoperable and a second position at which the connection is operable to pressurise the tank for emptying, and actuating means to which fluid pressure is applied to urge the member to the second position; said actuating means being connected to the pressure connection upstream of the pressure responsive valve by way of one or more auxiliary valves interlocked with components of the apparatus and/or an associated discharge installation to ensure that said components are correctly positioned or set for emptying the tank before the tank can be so pressurised.

2. Apparatus as in Claim 1 wherein the pressure responsive valve is a diaphragm actuated valve responsive to low purging fluid pressure.

3. Apparatus as in Claim 2 wherein the diaphragm actuated valve includes a closure member in the form of a poppet valve member displaceable by the action of the diaphragm in response to said fluid pressure from the first position to the second position.

4. Apparatus as in Claim 3 wherein the valve member closes the pressurising connection at the first position and opens it at the second position.

5. Apparatus as in Claim 3 or 4 wherein the valve member vents the tank to atmosphere at the first position and closes said venting at the second position.

6. Apparatus as in any one preceding claim including at least one inlet duct valve which is an automatic one-way non return valve.

7. Apparatus as in any one preceding claim including at least one inlet duct valve means which is a manually or fluid pressure actuated valve interconnected with the or one of the auxiliary valves to ensure that the inlet duct valve is closed before the tank is pressurised.

8. Apparatus as in any one preceding claim including an auxiliary valve in the form of a manual valve for selective control of the pressurising of the tank.

9. Apparatus as in any one preceding claim including an auxiliary valve associated with a connector for a static flexible or other discharge pipe to be operably releasably connected to the outlet duct whereby pressurising of the tank cannot occur until said connection has been properly made.

10. Apparatus as in any one preceding claim wherein the outlet duct rises from a lowermost sump portion of the tank.

11. Sewage collection and disposal apparatus substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

1 2. A railway carriage, boat or other passenger vehicle including apparatus as in any one preceding claim.