US20120124726A1

US20120124726A1 - WC Apparatus for Rail Vehicles

Info

Publication number: US20120124726A1
Application number: US12/949,922
Authority: US
Inventors: Ralph Gärtner; Jens-Christian Holst; Jan Papproth; Raymond Ullrich
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2010-11-19
Filing date: 2010-11-19
Publication date: 2012-05-24

Abstract

A WC apparatus for rail vehicles is provided. The WC apparatus includes a flushing liquid tank, a toilet and a collecting tank. Further, the apparatus has control device which automatically initiates discharges of doses of disinfectants and/or calcification inhibitors into flushing water in order to keep a pH value below an associated threshold value.

Description

FIELD OF INVENTION

The invention relates to a WC apparatus, having a flushing liquid tank, a toilet and a collecting tank, as used in rail vehicles, for example.

SUMMARY OF INVENTION

In a WC apparatus in transport engineering (rail, aircraft) with and without the addition of pH-acidic and pH-neutral biocidic disinfectants in the flushing water, it is sometimes possible for limescale and urine scale deposits to arise in the WC apparatus which can significantly impair functionality and result in total failure.
The procedure for removing deposits, such as limescale and/or urine scale, in WC apparatuses is to periodically perform tortuous cleaning of the WC apparatuses with decalcifiers. This means very significant maintenance involvement.
There is a relationship between the pH value of the flushing liquid, the amount of urine and feces introduced and the tendency toward calcification and urine scale formation in the waste water system of the WC apparatus. Within a particular range, above a limit value, any increase in the pH value increases the risk of urine scale and limescale deposits forming in the waste water system.
Against this background, the invention is based on the object of presenting a WC apparatus also for use in rail vehicles which is more maintenance-friendly in terms of avoiding calcification and ensuring the disinfecting action.
This object is achieved in the WC apparatus cited at the outset by virtue of a control device being provided which automatically initiates discharges of doses of disinfectants and/or calcification inhibitors into the flushing water in order to keep the pH value below an associated threshold value.
In this case, the control device of such a WC apparatus can be operated in regulated or else unregulated form.
In the case of regulated operation of the control device, said control device can monitor a profile of the pH value and, when the associated threshold value is exceeded, initiate the discharges of disinfectants and/or calcification inhibitors into the flushing water, wherein the control device has a connection for signaling purposes to at least one sensor for the pH value in order to monitor the pH value.
On account of the typically continuous monitoring of the profile of the pH value, it becomes possible to tell when measures to reduce the pH value need to be taken. In this context, one or more threshold values may be defined which initiate discharge of disinfectants and/or calcification inhibitors.
A first pH threshold value may be between 6 and 7, preferably 6.3, and the control device can discharge calcification inhibitors into the flushing water when this threshold value is exceeded. The choice of the first pH threshold value is based on empirical examinations by the inventors.
The same also applies to a second pH threshold value, which may be 8.0. Whenever this threshold value is exceeded, the control device discharges disinfectants into the flushing water, so that the disinfecting action is ensured.
In respect of maintaining an adequate disinfecting action, provision may be made for the control device to monitor a time profile of the pH value and, when a threshold value for a pH value increase is exceeded, to initiate discharge of additional disinfectant into the flushing water. In this respect, there are two alternative procedures available for prompting the discharge of additional disinfectant into the flushing water. With regard to the pH value increase, it may be necessary to consider a change in the pH value of one unit per hour to be a benchmark.
Preferably, the control device is of adaptive design and it optimizes respective doses of disinfectants and/or calcification inhibitors for discharge into the flushing water, on the basis of the profile of the pH value. By way of example, it is possible for the control device to discharge various doses of calcification inhibitors into the flushing water, and at the same time to monitor the time profile of the pH value, when the threshold value of 6.3 for the pH value is exceeded. It is then possible to detect a dependency of the pH value profile on the metered dose of calcification inhibitor. The result will then be that an optimum dose of calcification inhibitor is found which effectively lowers the pH value below the threshold value of 6.3. In this case, the control device is able to minimize the period for which the threshold value is exceeded for the purpose of optimization.
There is a plurality of alternatives for discharging the doses of disinfectants and/or calcification inhibitors. Said discharge may be directly into a flushing line or else directly into the toilet, for example.
The WC apparatus may also be provided with a control device in which no active regulation takes place, but instead the aims of this invention are achieved automatically in another way. By way of example, the control device can initiate the discharge of the doses of disinfectants and/or calcification inhibitors on the basis of detection of a degree of use of the WC apparatus. This means that after the WC flushing apparatus has been operated a number n of times, the discharges to which reference has been made take place automatically, for example. Alternatively, provision may be made for the control device to have a timer which it uses to initiate the discharge of the doses of disinfectants and/or calcification inhibitors into the flushing water at fixed intervals of time. The illustrated alternatives are therefore based either on use or on time, so that the pH value is kept in a suitable range without the use of any kind of sensors.
During unregulated operation, the control device can discharge firmly set doses of disinfectants and/or calcification inhibitors. The pH threshold value may be between 6 and 7.
In other words, use-dependent or time-interval-controlled discharge—without checking the pH value by means of a sensor—of disinfectants and/or calcification inhibitors could take place over the period of use of the WC installation.

BRIEF DESCRIPTION OF THE DRAWINGS

An exemplary embodiment of the invention is explained in more detail below with reference to the drawing. The single FIGURE shows a schematic block diagram illustration of a WC apparatus.

DETAILED DESCRIPTION OF INVENTION

The WC apparatus shown has a flushing liquid tank 1, the flushing liquid in which is used to purge feces from a toilet 2. Purged feces are routed to a collecting tank 3.
The flushing liquid tank 1 is connected by means of respective valves 4, 5 both to a reservoir 6 containing calcification inhibitors and to a reservoir 7 containing disinfectants.
The effect intended to be achieved in the WC apparatus is now that calcification is reduced and a required degree of disinfection is ensured. For this purpose, a pH value in the WC apparatus is continuously monitored. In the present exemplary embodiment, two pH value sensors 8, 9 are provided, one of which is arranged within the line connection between toilet 2 and collecting tank 3 and the other of which is arranged within the collecting tank 3.
A control device 10 is connected for signaling purposes to the pH value sensors 8, 9 and, on the basis of recorded measured values, forms a representative pH value which can then be compared with threshold values. In this case, a first pH threshold value is 6.3. When it is exceeded, this prompts the control device 10 to actuate the valve 4 such that a suitable dose of calcification inhibitor is discharged from the reservoir 6 into the flushing liquid tank 1. Besides the calcification inhibitors, it is additionally alternatively possible to discharge complexing agents, such as citric acid.
When the pH value of approximately 8.0 is exceeded, there is the risk that the disinfecting action is no longer adequate. If this threshold value is exceeded, or the pH value increases significantly over a certain period, the control device 10 prompts the discharge of a suitable dose of disinfectants from the reservoir 7 into the flushing liquid tank 1, specifically by opening the valve 5. Alternatively, the discharge may also be directly into the flushing line or the toilet 2. This applies to all modes of operation of the control device 10.
The control device 10 is of adaptive design, i.e. it is capable of discharging various doses of disinfectants and/or calcification inhibitors/complexing agents into the flushing liquid tank 1 and at the same time of observing the time profile of the pH value. In this way, it is possible to optimize the doses at which the prescribed threshold values remain reliably undershot.
The invention can be used both for recirculating WC apparatuses—this is indicated by means of a dashed line in the FIGURE—or else to nonrecirculating WC apparatuses, as are used for WC apparatuses in the leisure/camping sector and in the commercial sector, for example.
Unregulated operation of the control device 10 is performed such that the control device 10 discharges a firmly set volume of disinfectants and/or calcification inhibitors into the flushing liquid tank 1 or directly into the line for the flushing liquid before the toilet 2 at an interval of time or after the WC apparatus has been used. This results in essentially the same design as that shown in the FIGURE. Only the sensors 8, 9 and their supply lines are missing. Instead, the control device 10 has a timer or means for detecting a degree of use of the WC apparatus.

Claims

1.-15. (canceled)

16. A WC (water closet) apparatus, comprising:

a flushing liquid tank;

a toilet;

a collecting tank; and

a control device which automatically initiates discharges of doses of disinfectants and/or calcification inhibitors into flushing water in order to keep a pH value below an associated threshold value.

17. The WC apparatus as claimed in claim 16, wherein the control device monitors a profile of the pH value and, when the associated threshold value is exceeded, initiates the discharges of disinfectants and/or calcification inhibitors into the flushing water.

18. The WC apparatus as claimed in claim 17, further comprising:

a sensor connected to the control device, the sensor measuring the pH value and transmitting the pH value to the control device.

19. The WC apparatus as claimed in claim 17, wherein a first pH threshold value is between 6 and 7 and the control device discharges calcification inhibitors into the flushing water when the first threshold value is exceeded.

20. The WC apparatus as claimed in claim 17, wherein a second pH threshold value is 8.0 and the control device discharges disinfectants into the flushing water when the second threshold value is exceeded.

21. The WC apparatus as claimed in claim 19, wherein a second pH threshold value is 8.0 and the control device discharges disinfectants into the flushing water when the second threshold value is exceeded.

22. The WC apparatus as claimed in claim 16, wherein the control device monitors a time profile of the pH value and, when a threshold value for a pH value increase is exceeded, initiates discharge of additional disinfectant into the flushing water.

23. The WC apparatus as claimed in claim 17, wherein the control device is configured to adapt and optimize respective doses of disinfectants and/or calcification inhibitors for discharge into the flushing water on the basis of the profile of the pH value.

24. The WC apparatus as claimed in claim 23, wherein the control device is configured to minimize a period for which the threshold value is exceeded for the purpose of optimization.

25. The WC apparatus as claimed in claim 18, wherein the sensor is arranged in the collecting tank.

26. The WC apparatus as claimed in claim 25, wherein a further sensor is arranged upstream of the collecting tank.

27. The WC apparatus as claimed in claim 18, wherein a further sensor is arranged upstream of the collecting tank.

28. The WC apparatus as claimed in claim 16, wherein the doses of disinfectants and/or calcification inhibitors are discharged directly into a flushing line.

29. The WC apparatus as claimed in claim 16, wherein the doses of disinfectants and/or calcification inhibitors are discharged directly into the toilet.

30. The WC apparatus as claimed in claim 16, wherein the control device is configured to initiate the discharges of the doses of disinfectants and/or calcification inhibitors based upon a degree of use of the WC apparatus.

31. The WC apparatus as claimed in claim 16, wherein the control device includes a timer for initiating the discharge of the doses of disinfectants and/or calcification inhibitors into the flushing water at fixed intervals of time.

32. The WC apparatus as claimed in claim 30, wherein the control device discharges firmly set doses of disinfectants and/or calcification inhibitors.

33. The WC apparatus as claimed in claim 31, wherein the control device discharges firmly set doses of disinfectants and/or calcification inhibitors.