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(11) | EP 1 291 468 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
| published in accordance with Art. 158(3) EPC |
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| (54) | VACUUM FLUSH SYSTEM WITH TEMPORARY-RETENTION WASTE WATER TANK |
| (57) It comprises a wastewater tank (2) to which is connected at least one toilet bowl
(1) and which has an outlet pipe (7) with a discharge valve (8); said tank (2) is
placed under the floor (P) of the railway carriage and said outlet pipe (7) is open
at its bottom part facing down on to the track, the discharge valve (8) being connected
to a control module (6). It does not require maintenance and occupies a small space. |
[0001] The present invention relates to a vacuum disposal system with wastewater temporary retention tank for railway carriages, of the type that includes a wastewater tank to which is connected at least one toilet bowl and which has an outlet pipe with a discharge valve.
BACKGROUND OF THE INVENTION
[0002] Vacuum disposal systems for railways involve the fitting of toilets whose outlets have traditionally been connected to a wastewater collector tank of high capacity. This tank must be emptied at intervals, for example when the train reaches one of the ends of its route, and this naturally complicates and increases the cost of maintenance of the installation.
[0003] Moreover, it should be taken into account that in systems designed for railways it is always preferable to avoid high volumes and weights, such as those involved in a tank of this type.
[0004] Another disadvantage of this system with general tank is that the stations need to have suitable equipment for emptying such tank.
[0005] Some recent systems include an intermediate tank, having a volume of four or five litres, connected to each toilet bowl, so that one dose of wastewater passes rapidly and with low energy consumption from the bowl to the intermediate tank, and this intermediate tank later discharges into a larger tank, which is emptied at intervals.
[0006] This design improves the efficiency of the system, due to the fact that it requires lower consumption for emptying the contents of the toilet bowl into the intermediate tank, but it does not eliminate the above-mentioned disadvantages associated with the maintenance, volume and weight of the system.
DESCRIPTION OF THE INVENTION
[0007] The object of the present invention is to solve the aforesaid disadvantages by developing a vacuum-disposal system that does not require maintenance and occupies a small space.
[0008] In accordance with this object, the vacuum-disposal system of the present invention is characterised in that said tank is placed under the floor of the railway carriage and in that said outlet pipe is open at its bottom part facing down on to the track, the discharge valve being connected to a control module.
[0009] Thanks to these structural characteristics, after a predetermined number of operating cycles of the toilet the wastewater tank can be emptied automatically when the train is running through an uninhabited zone, thereby eliminating the need for maintenance operations related with emptying of the tank. Furthermore, the tank can be small in size and of low weight.
[0010] Preferably, the tank is substantially cylindrical and is placed vertically underneath the floor of the carriage, the outlet pipe being connected at its bottom part.
[0012] In accordance with a preferred embodiment of the invention, the tank has associated therewith a level detector; the emptying process can thus be activated either after a certain number of operating cycles or when a certain level of wastewater is reached, thereby preventing excessive filling of the tank from occurring.
[0013] Advantageously, the tank has a volume of between five and twenty litres; in a preferred embodiment, it has a volume of about ten litres.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] For a better understanding of all that has been outlined some drawings are attached which show, schematically and solely by way of non-restrictive example, a practical case of embodiment.
[0015] In said drawings, the sole figure shows a diagram of a vacuum disposal system in accordance with one embodiment of the invention, fitted onto a railway carriage.
DESCRIPTION OF A PREFERRED EMBODIMENT
[0016] The system essentially comprises a toilet bowl 1, a wastewater tank 2 to which is connected the outlet from the bowl 1 through a cut-off valve 3 and a pipe 4, a pneumatic unit 5 which includes electrically-operated valves for controlling the various organs of the system and an ejector for causing vacuum into the tank 2, and a control module 6.
[0017] In accordance with one particular feature of the invention, the tank 2 is mounted underneath the floor P of the carriage and has at its lower part an outlet pipe 7 with a discharge valve 8, governed by the control module 6, as will be explained below. The outlet pipe 7 is open at its lower part, so that the wastewater discharged from the tank 2 drops onto the track.
[0018] Associated with the tank, provision is also made for a level detector 9, whose signal is supplied to the control module 6.
[0019] The tank 2 can have a capacity of some ten litres, although this figure is not restrictive; in any case, the volume of the tank 2 must be suitable for housing at least some wastewater discharge units from the toilet bowl 1.
[0020] The pneumatic assembly 5 and the control module 6 have connections (in general not shown) to the various pneumatic and electrical components of the system.
[0021] In particular, on the one hand, the ejector (not shown) of the pneumatic assembly 5 is connected through a pipe 10 to the tank 2, such as to cause a depression therein, synchronised with the opening of the cut-off valve 3 and with the discharge of water in the toilet bowl 1, all this with the function that a unit of wastewater passes from the toilet bowl 1 to the tank 2.
[0022] On the other hand, the discharge valve 8 from the tank is controlled by one of the electrically-operated valves of the pneumatic assembly 5, which is in turn governed by the control module, as will be described below.
[0023] In accordance with the invention, the contents of the tank are emptied onto the track when the conditions are appropriate, that is, away from inhabited centres. For this purpose, the control module 6 governs the discharge from the tank by opening the discharge valve 8 when, following completion of a predetermined number of toilet bowl discharge cycles, or once a certain level in the tank (indicated by the level detector 9) has been reached, the train is travelling at a speed higher than a predetermined threshold, for example 40 km/h. This ensures that the train is in an uninhabited zone; furthermore, thanks to the speed of the train, the discharge takes place over a relatively long section of the track, thereby minimising its impact.
[0024] Thanks to this characteristics, the tank of the system of the invention can be of relatively low volume and occupy little space, and at the same time it does not require intervention at intervals in order to empty it.
[0025] When the discharge valve 8 is opened, the emptying of the tank can occur simply by gravity or by simultaneously inducing a partial pressure in the tank itself through a suitable connection (not shown in the figures) with an element of the pneumatic assembly.
[0026] Although one specific embodiment of this invention has been described and shown, it is obvious that an expert in the subject would be able to introduce variations and make changes, or replace the details by others that are technically equivalent, without departing from the scope of protection defined by the appended claims.
[0027] For example, although an approximately cylindrical tank, arranged vertically, has been shown, the geometric characteristics and orientation could be changed. Similarly, a single tank could be used for more than one toilet bowl, depending on its volume and the layout of the toilets in the carriage.
[0028] On the other hand, the operating parameters of the discharge, such as the number of cycles before the discharge is carried out, or the cited threshold speed, will depend on the characteristics of the system and on the zone through which the train is travelling, and will preferably be programmable.
1. A vacuum disposal system with wastewater temporary retention tank for railway carriages,
which includes a wastewater tank (2) to which is connected at least one toilet bowl
(1) and which has an outlet pipe (7) with a discharge valve (8), characterised in that said tank (2) is placed under the floor (P) of the railway carriage and in that said outlet pipe (7) is open at its bottom part facing down on to the track, the
discharge valve (8) being connected to a control module (6).
2. A disposal system as claimed in Claim 1, characterised in that said tank (2) is substantially cylindrical and is placed vertically underneath the
floor (P) of the carriage, the outlet pipe (7) being connected at its bottom part.
3. A disposal system as claimed in Claim 1 or Claim 2, characterised in that the tank (2) has associated with it a level detector (9).
4. A disposal system as claimed in any of the preceding claims, characterised in that the tank (2) has a volume of between five and twenty litres.
5. A disposal system as claimed in Claim 4, characterised in that the tank (2) has a volume of about ten litres.