Vacuum toilet and vacuum tank for a vacuum toilet

Description

Technical field

[0001] The invention relates to a vacuum tank for a vacuum toilet, wherein the vacuum tank comprises an inlet opening arranged on a side wall of the tank, which can be connected to the main outlet of a shell via an intermediate valve, and an outlet opening arranged at the lowest point for conveying the extracted wastewater stream, and wherein furthermore the air in the tank can be vacuumed to a pressure below atmospheric pressure via the outlet opening or via further openings in the vacuum tank, wherein the vacuum tank is divided into an upper and a lower volume by a separating element, and wherein the separating element is arranged approximately at the level of the inlet opening in the tank.

[0002] Furthermore, the invention relates to a vacuum toilet comprising a shell with a main drain, a flushing mechanism, a vacuum tank with an inlet opening arranged in a side wall and an outlet opening arranged at the lowest point, wherein the main drain of the shell is connected to the inlet opening of the vacuum tank via a valve, and a control unit with at least one operating unit for the user, via which a flushing process can be triggered. State of the art

[0003] Vacuum toilets are often used in vehicles, ships, or trains because they require very little flushing water. Typically, only about one liter of water is needed per flush. The bowl, whose main drain is closed by a valve, is first rinsed with this amount of water. Then, the flush water, along with feces, urine, and paper, is sucked out through the valve at high speed. To achieve sufficient suction, a vacuum tank of appropriate size is necessary, which is first evacuated using a pump. When the valve is opened, a rapid pressure equalization occurs, drawing the entire wastewater stream into the vacuum tank. The valve is then closed, and the wastewater stream is carried away from the vacuum tank.

[0004] Due to their low water consumption, these types of toilets are also attractive for use as composting toilets, where wastewater streams containing feces are to be separated from those without and directed to separate applications. In this context, a particularly low flushing water requirement for the further processing of the wastewater streams is also advantageous.

[0005] It has been shown that a limiting factor for the amount of flushing water available is the vacuum tank. It must have a certain volume, usually several liters, for example, 6 to 8 liters for an average toilet, to provide the necessary suction for a flush. During the flush itself, the wastewater stream, consisting of feces, urine, paper, and flush water, is sucked into the tank at high speed. This causes an explosive distribution across the entire inner walls of the vacuum tank upon entry, especially with a wastewater stream laden with feces. To prevent the vacuum tank from gradually becoming clogged and its function impaired as the wastewater stream travels along the walls, the amount of flushing water cannot be reduced further.

[0006] Especially when using a composting toilet, where fecal streams with a high solids content are to be fed into a further treatment process with a high solids content, it is necessary to significantly reduce the flushing water volume again to avoid the need for subsequent energy-intensive treatment of the fecal stream. If the wastewater streams are to be treated differently depending on their type even after passing through the vacuum tank, the flushing water volume must still be high enough to minimize cross-contamination between successive wastewater streams between flushes.

[0007] EP 0330490 B1 shows a wastewater tank for a vacuum wastewater system installed in a transport vehicle. The tank has a cyclone separator for moisture droplets contained in the airflow. The tank's construction is complex and requires many individual parts, and the devices shown do not serve to save flushing water.

[0008] EP 0287350 A2 and WO 2006 / 104231 A1 each show vacuum toilet systems with macerating devices for feces. Separation elements for saving flushing water by reducing the tank volume available for wastewater are not shown. Description of the invention

[0009] The object of the present invention is therefore to provide a vacuum tank for a vacuum toilet, by means of which the flushing water requirement can be significantly reduced. Furthermore, it is an object of the present invention to provide a vacuum toilet with low flushing water requirements, which can also be used as a composting toilet, in which the different wastewater streams can be processed separately even after passing through the vacuum tank. The design of both the vacuum tank and the vacuum toilet should be modified as little as possible compared to known systems, so that largely standardized components can be used, thereby keeping manufacturing costs low.

[0010] This problem is solved, firstly, by a vacuum tank which has a separating element that, together with a side wall section of the vacuum tank, forms a downwardly open channel running along the circumference of the tank, preferably helically shaped, which extends from the inlet opening at least once around the substantially horizontal circumference towards the lower volume, and wherein a through-opening is arranged centrally in the separating element between the upper and lower volumes, which is funnel-shaped towards the lower volume, and wherein optionally the upper surface of the separating element is also funnel-shaped towards the through-opening. The use of the separating element allows the amount of rinsing water to be significantly reduced.During the flushing process, the wastewater flow is slowed as it travels along the longer path of the circumferential channel from the inlet opening, allowing it to spread only downwards into the lower volume. This prevents an explosive distribution throughout the entire interior of the vacuum tank. The wastewater flow is thus directed precisely to the outlet opening located in the lower volume of the vacuum tank. The upper volume never comes into contact with the wastewater flow and is therefore solely dedicated to creating the vacuum. This allows the channel and the lower volume to be cleaned with less flushing water per cycle. Tests have shown that a reduction in the amount of flushing water to just 300 ml is possible, while still ensuring that the entire relevant section of the channel and the lower volume are completely flushed in a single cycle. This was even achievable with heavily contaminated fecal streams, such as those resulting from diarrhea.The opening in the partition allows the entire volume of the vacuum tank to be used to generate the vacuum for the next rinsing cycle. The partition can be positioned exactly in the middle of the vacuum tank or, preferably, offset in the lower half, for example, at one-third of its height.

[0011] The funnel-shaped design of the opening in the separating element further ensures that the upper volume of the vacuum tank remains uncontaminated. Even if a wastewater stream were to spread at a higher velocity in the lower volume, the funnel-shaped design of the opening ensures that virtually no liquid reaches the upper volume. Even if some of the wastewater stream were to pass through the opening into the upper volume, it would be directed back towards the opening and into the lower volume via a funnel-shaped top surface of the separating element.

[0012] According to a further preferred feature, the separating element is formed integrally with a tank section forming the lower volume and is connected to a tank section forming the upper volume via the through-opening. For manufacturing reasons, it can be advantageous if the separating element and the tank section forming the lower volume are manufactured as a single unit. The lower tank section has the inlet opening in the area of ​​the separating element and the outlet opening at its lowest point. The separating element forms the top surface for this tank section and has the through-opening facing upwards. A further tank section, forming the upper tank volume, can then be connected to the lower tank section via the through-opening.The upper tank volume can be funnel-shaped in its lower area towards the through-opening.

[0013] The object of the invention is further achieved by a vacuum toilet of the aforementioned type, characterized in that the vacuum tank is divided into an upper and a lower volume by a separating element, wherein the separating element is arranged approximately at the level of the inlet opening in the tank and optionally, together with a side wall section of the vacuum tank, forms a downwardly open channel extending along the circumference of the tank, preferably helically shaped, which extends from the inlet opening at least once around the substantially horizontal circumference towards the lower volume, and wherein a passage opening between the upper and lower volumes is arranged centrally in the separating element. By providing a corresponding vacuum tank in a vacuum toilet, the advantages described above are also realized here.Apart from the position of the inlet opening on the vacuum tank and the installation of the separating element, standard components can still be used, thus keeping manufacturing costs low.

[0014] The opening in the separating element is funnel-shaped towards the lower volume, and optionally, the upper surface of the separating element is also funnel-shaped towards the opening. As described above, this has the advantage that practically no portion of the wastewater flow can enter or remain in the upper volume of the vacuum tank.

[0015] As already described above in connection with the vacuum tank, another preferred feature is that the separating element is formed in one piece together with a tank section forming the lower volume and is connected to a tank section forming the upper volume via the through-opening. This can offer advantages for cost-effective manufacturing.

[0016] According to a preferred embodiment, a three-way valve with one inlet and two outlets is provided downstream of the vacuum tank's outlet opening. This valve can be controlled via the control unit to direct the wastewater flow into two different downstream drain lines, depending on whether it is a urine or fecal flow. A vacuum toilet designed in this way allows for the effective separation of different wastewater flows. For example, a wastewater flow consisting of urine, flush water, and possibly paper can be directed to one outlet, while a wastewater flow consisting of feces, flush water, paper, and urine is directed to another. Due to the low flush water content, it is possible to achieve fecal wastewater flows with a solids content of 7-12%. This allows the corresponding fecal wastewater flow to be further processed in an energy-efficient manner.

[0017] According to a possible preferred design, the three-way valve is switched via input on the control unit. In the simplest case, the switch between the two drain lines occurs as soon as the flush is initiated. As with conventional water-saving toilets, the user has, for example, a flush button for "small" and "large" flush, and decides whether the wastewater stream contains fecal matter or not by pressing the button. In this case, the amount of flush water is not changed, but only the three-way valve is set accordingly. However, since this type of flush button is already familiar to most users, no new operation needs to be learned, and the number of incorrect uses is minimized.

[0018] Alternatively, according to a preferred alternative, a sensor unit is provided in the basin, connected to the control unit, to detect the type of wastewater flow, specifically whether it is urine or fecal. The three-way valve is then switched based on the sensor data via a control pulse from the control unit. To eliminate any user error, the selection of the correct drain line can also be made using a sensor unit that provides the corresponding information to the control unit. One possible sensor is an optical sensor mounted in the basin, which detects the basin's contents and then transmits whether or not it is fecal wastewater. This measurement is also taken when the flushing process is initiated, and the control unit evaluates the sensor reading and adjusts the three-way valve accordingly.It is obvious to the average person with expertise that other equivalent designs are possible instead of a three-way valve. For example, the vacuum tank could have two separate outlet openings at its lowest point, each equipped with its own valve that can be controlled by the control unit.

[0019] An additional preferred feature of the vacuum toilet is that a further separating device for diverting a large portion of the urine flow is already provided in the bowl upstream of the main outlet. This allows for even more effective separation of the wastewater streams. A particularly simple separating device for diverting the urine flow is disclosed, for example, in AT 521114. In the solution described therein, the urine flow is directed directly over the bowl wall into a separate outlet due to the teapot effect. As a result, the main outlet of the bowl only contains wastewater streams that either consist solely of feces, paper, and flush water, or only paper and flush water.

[0020] Another preferred feature is the inclusion of a filter system in the downstream drain line for the fecal-free wastewater stream, located after the three-way valve. To remove paper from the urine stream or the nearly pure flushing stream, a suitable filter system can be used. Various solutions exist in the prior art, such as separation via a screw, a centrifuge, or similar devices. If the urine stream is separated within the bowl, a clean flushing stream can then be easily treated for re-flushing after passing through the filter system. This further reduces the overall water consumption of the vacuum toilet.

[0021] Finally, another preferred feature is the arrangement of a macerator pump downstream of the outlet opening. This pump conveys the wastewater stream from the vacuum tank and, if necessary, homogenizes it. Downstream of the macerator pump, a three-way valve with one inlet and two outlets is optionally provided. One outlet is connected to the outflow line, and the second outlet is connected via a return line to the lower volume of the vacuum tank. Particularly with a wastewater stream containing fecal matter, such as toilet paper, it is advantageous to homogenize the wastewater stream for further transport and treatment. To achieve sufficient homogenization, a macerator pump can be provided to pump the wastewater stream from the lower volume of the vacuum tank.Due to the very small volume of rinse water, a single pass through the macerator pump may not result in sufficient homogenization. Therefore, recirculation into the lower volume of the vacuum tank may be necessary. This allows the relevant wastewater stream to be pumped back into the vacuum tank and thus repeatedly transported through the macerator pump until it is completely homogenized. The homogenized wastewater stream is then directed into the discharge line and fed into further treatment, as described above. The macerator pump and the duration of the recirculation cycle are also controlled by the control unit. Brief description of the drawings

[0022] The invention will now be described in greater detail with reference to exemplary embodiments and the accompanying figures. Figs. 1 and 2different schematic views of a vacuum tank according to the invention, Fig. 3 and 4 different schematic views of a separating element, Figs. 5 to 8 Schematic circuit diagrams of possible embodiments of vacuum toilets according to the invention with a vacuum tank arranged therein, Fig. 9 A schematic sectional view of a lower tank section with an integrated separating element at the top. Way(s) to implement the invention

[0023] In the Figs. 1 and 2 A vacuum tank 1 according to the invention is shown schematically. Fig. 1 The tank itself is shown in section, while a built-in separating element 7 is shown in its entirety with dashed, invisible lines. In the Fig. 2The same representation is shown in a top view. The vacuum tank 1 has an inlet opening 2 on one side wall, approximately just below half its height. At the lowest point of the vacuum tank 1 is an outlet opening 6. The internal volume of the vacuum tank is divided into an upper volume 8 and a lower volume 9 by the integrated partition 7. The partition 7 has a helically extending, downwardly open channel 10, which slows down the incoming wastewater flow from the inlet opening 2 across the circumference of the vacuum tank 1 and directs it downwards towards the outlet opening 6. In the center of the partition 7 is a through-opening 11, which is particularly important in Fig. 2As can be seen, the opening is funnel-shaped and tapers downwards. Furthermore, the upper surface of the separating element 1 is also funnel-shaped, extending towards the opening 11. This makes it very difficult for wastewater to enter the upper volume 8, and even if it does, it is immediately directed downwards through the opening 11 to the outlet 6 via the funnel-shaped surfaces.

[0024] In the Fig. 3 The separating element 7 is shown alone in a perspective view and in the Fig. 4 in a longitudinal section. As can be seen, the separating element 7 in the illustrated embodiment is designed as a funnel, with the helically downwardly open channel 10 formed around the downwardly projecting funnel nozzle. The separating element 7 can thus be designed as a single-piece component.

[0025] In Fig. 5Figure 1 shows a schematic circuit diagram of a possible embodiment of a vacuum toilet according to the invention. A bowl 5 with a main outlet 4 is connected via a valve 3 to the inlet opening 2 of a vacuum tank 1 described above. Downstream of the outlet opening 6 of the vacuum tank 1, a three-way valve 13 with one inlet and two outlets is connected. At each of the two outlets, a drain line 15 is provided for a wastewater flow containing feces and a drain line 14 for a wastewater flow free of feces. The vacuum toilet also has a control unit 12, which is connected to an operating unit 19, a vacuum pump 18, a sensor unit 20, and the valves 3 and 13.

[0026] A flushing cycle is initiated via the control unit 19. The control unit 19 can be designed to allow the user to select a corresponding button for the type of wastewater flow. In this case, a sensor unit 20 is not necessary, and the three-way valve 13 is controlled by the user. If only a single flush button and a sensor unit 20 are present, the sensor unit 20 is activated when the control unit 19 is pressed. This unit then determines the type of wastewater flow. The sensor unit 20 can, for example, include an optical sensor mounted in the basin 5, which detects the contents of the basin. Subsequently, flushing water is pumped into the basin, and a vacuum is created in the vacuum tank 1. Following this, the valve 3 below the main outlet 4 of the basin 5 is opened, and the contents of the basin are drawn into the vacuum tank 1.The separating element 7 slows the wastewater flow over the side wall of the tank and directs it into the lower volume 9 of the vacuum tank 1. Once the contents of the shell 5 have been completely extracted, the valve 3 upstream of the inlet opening 2 is closed again, and the three-way valve 13 is opened by the control unit 12, depending on the type of wastewater flow, to one of the two discharge lines 14, 15. If necessary, when the three-way valve 13 is opened, the vacuum pump 18 can also create overpressure inside the vacuum tank 1 to expel the contents of the lower volume 9 from the tank.

[0027] During the Fig. 6In the illustrated embodiment, a further separating device 16 is provided in the bowl 5, through which the urine flow can be directly diverted. In principle, any known separating device 16 for the urine flow in the bowl 5 can be provided. Preferably, it is a separating device such as that disclosed in AT 521114, in which the urine flow is directly diverted via a secondary drain in the bowl 5 using the teapot effect. The flushing process is controlled in the same way as in the embodiment described above. Fig. 5 described. Another difference in the embodiment according to Fig. 6The system consists of a filter unit 17 in the drain line 14 for the fecal-free wastewater stream. Here, toilet paper, for example, is separated from the wastewater stream. The toilet paper, considered a "solid" component, can, after separation via the filter unit 17, be fed into the fecal-laden wastewater stream in the other drain line 15 and processed together with it. In the example shown, the wastewater stream remaining after the filter unit 17, which contains only flush water and traces of urine, is combined with the urine wastewater stream from the separator 16 for the urine stream and processed further. However, it is also possible to separately feed the flush water stream into a reprocessing unit for further treatment.

[0028] The one in Fig. 7 The illustrated embodiment shows in its essential elements the arrangement according to Fig. 6Here, a further separation of the fecal-free wastewater stream takes place downstream of the filter unit 17. To separate a wastewater stream containing a certain amount of urine from a wastewater stream consisting almost entirely of rinse water, another directional control valve 23 is provided downstream of the filter unit, which is also controlled by the control unit 12. The directional control valve 23 can be controlled in various ways; for example, time-separated cleaning rinse cycles can be separated from wastewater rinse cycles, or the control can be based on another sensor unit 20, which is arranged in the filter unit 17. This sensor could, for example, be a conductivity sensor that measures the urine content in the wastewater stream in the filter unit 17.Based on this information, the control unit 12 can either open the directional control valve 23 towards a flush water treatment unit 22, or, in the case of a higher urine concentration, direct the wastewater flow to a urine stream treatment unit 21. The urine stream separator 16, already provided in the bowl 5, also feeds into the urine stream treatment unit 21. This additional separation option allows urine wastewater flows to be effectively distinguished and separated from flush water flows, even when the toilet is in use while upright.

[0029] Fig. 8Figure 1 shows another possible embodiment in which the entire wastewater flow is transferred via the main outlet 4 into the vacuum tank 1 and subsequently treated into different streams. For this purpose, a macerator pump 25 is connected downstream of the outlet opening 6 of the vacuum tank 1. This pump transports and homogenizes the wastewater flow located in the lower volume 9 of the vacuum tank 1. If the wastewater flow is urine, it is diverted via the three-way valves 26, 13 and the directional valve 23 located downstream of the macerator pump 25 towards a urine stream treatment unit 21. If the flow is pure rinse water, it is diverted via a filter unit 17 into a rinse water treatment unit 22. The filter unit 17 can, of course, also be arranged between the three-way valve 13 and the directional valve 23.The control of the flushing processes and the positions of valves 26, 13, and 23 are again controlled by the control unit 12, either based on user input at the operating unit 19 or based on sensor units 20. To achieve the lowest possible water consumption, the wastewater streams are largely separated from the flushing processes. For example, in the case of a urine wastewater stream, it is first extracted via the vacuum tank 1 during the flushing process and directed to the corresponding urine stream treatment unit. This is followed by a separate flushing cycle with approximately 1 liter of water, which is then fed into the flushing water treatment unit 22.

[0030] If the wastewater stream is contaminated with fecal matter, the small amount of water used in the rinsing process may prevent the wastewater stream from being sufficiently homogenized during its first pass through the macerator pump 25. Here, too, the rinsing process is carried out separately to save water. For example, only 0.3 liters of water are used to transport the fecal matter. Therefore, the control unit can switch the three-way valve 26 towards a return line 27, which is connected to the lower volume 9 of the vacuum tank 7. This allows the wastewater stream to be circulated through the macerator pump 25 several times until it is sufficiently homogenized. It is then diverted via the three-way valves 26 and 13 towards a discharge line 15 for the fecal matter stream. Only then does the actual cleaning rinse cycle for the shell 5 and the lower volume 9 of the vacuum tank 1 take place, for which approximately...1.5 liters of flushing water are used. Due to the low level of soiling, this flushing water can then also be reused via the flushing water treatment system 22. In total, such a toilet then has an extremely low total flushing water consumption of only about 2.6 liters per day, compared to about 40 liters for a conventional vacuum toilet or even about 200 liters for a conventional flush toilet.

[0031] In Fig. 9A possible embodiment of a lower tank section 24 is shown in a schematic sectional view. The lower tank section 24, together with the separating element 7, forms the upper end of the tank section 24 as a single unit. The channel 10 is formed by the separating element 7 together with the uppermost wall section of the side walls of the lower tank section 24. The inlet opening 2 leads into the lower tank section 24 in the area of ​​the separating element 7, and the outlet opening 6 is located at the lowest point. The through-opening 11 is located at the top, to which an upper tank section (not shown) can be connected to increase the vacuumable volume. Depending on the application and required vacuum, upper tank sections with different geometries or volumes can be arranged. The lower tank section always remains the same, which keeps manufacturing costs low.

[0032] The present invention thus makes it possible to create a vacuum toilet which, on the one hand, can be operated with extremely small amounts of flushing water, and, on the other hand, when used as a separating toilet, produces even better separable and already concentrated wastewater streams, which also means significant energy savings for the further treatment of these wastewater streams.

Claims

1. Vacuum tank (1) for a vacuum toilet, the vacuum tank (1) comprising a side wall having an intake port (2) connectable to a drain (4) of a toilet bowl (5) via an interposed valve (3) and an output port (6) at a lowest point for passage of an extracted waste-water stream, and furthermore air in the tank being maintained via the output port (6) or via further openings in the vacuum tank (1) at a sub atmospheric pressure, wherein a partition (7) divides the vacuum tank (1) into an upper compartment (8) and a lower compartment (9), the partition (7) being approximately level with the intake port (2) in the tank, characterized in that, a downwardly open groove (10) is formed together with a side wall of the vacuum tank (1) in a preferably helicoidally shape, that, starting from the intake port (2), runs at least once around the substantially horizontal circumference toward the lower compartment (9), and wherein a passage (11) extends centrally in the partition (7) between the upper compartment (8) and lower compartment (9), and wherein the passage (11) in the partition (7) tapers at a lower end like a funnel downward and an upper end of the passage (11) of the partition (7) also optionally flares like a funnel upward.

2. Vacuum tank (1) for a vacuum toilet according to claim 1, characterized in that the partition (7) is formed in one piece together with a tank section (24) forming the lower compartment and is connected via the passage (11) to a tank section forming the upper compartment.

3. Vacuum toilet with a bowl (5) with a main drain (4), a rinsing device, a vacuum tank (1) according to claim 1 with a side wall having an intake port (2) and an output port (6) at a lowest point, a valve (3) connecting the main drain (4) of the bowl (5) to the intake port (2) of the vacuum tank (1), and a controller (12) having at least one operator unit (19) for the user for initiating a flushing process, characterized in that a partition (7) divides the vacuum tank (1) into an upper compartment (8) and a lower compartment (9), the partition (7) being approximately level with the intake port (2) in the tank and together with a side wall section of the vacuum tank (1) forms a preferably helicoidally shaped, downwardly open groove (10) that, starting from the intake port (2), runs at least once around a substantially horizontal circumference toward the lower compartment (9), and wherein a passage (11) extends centrally through the partition (7) between the upper compartment (8) and lower compartment (9), which passage (11) is funnel shaped toward the lower compartment (9), and optionally an upper side of the partition (7) is formed as a funnel.

4. Vacuum toilet according to claim 3, characterized in that the partition (7) is formed in one piece together with a tank section (24) forming the lower compartment and is connected via the passage (11) to a tank section forming the upper compartment.

5. Vacuum toilet according to claim 3 or 4, characterized in that a three-way valve (13) with an inlet and two outlets is provided downstream of the output port (6) of the vacuum tank (1) that can be controlled by the controller (12) in order to direct a waste-water stream into two different downstream outflow lines (14, 15) depending on whether the stream is a urine or faecal stream.

6. Vacuum toilet according to claim 5, characterized in that the three-way valve (13) is switched by input to the operator unit (19).

7. Vacuum toilet according to claim 5, characterized in that the bowl (5) has a sensor (20) that is connected to the controller (12) and that detects the type of waste-water stream, namely whether it is a urine or faeces stream, and the three-way valve (13) is switched over by the controller (12) on the basis of the sensor data.

8. Vacuum toilet according to one of claims 3 to 7, characterized in that a further diverter (16) for discharging most of the urine stream is already provided in the bowl (5) upstream of the main drain (4).

9. Vacuum toilet according to one of claims 5 to 8, characterized in that a filter device (17) is provided in the outflow line (14) downstream of the three-way valve (13) for a waste-water stream free of faeces.

10. Vacuum toilet according to one of claims 3 to 9, characterized in that a comminution pump (25) is provided downstream of the output port (6) for conveying and optionally homogenizing the waste-water stream coming from the vacuum tank (1), wherein a three-way valve (26) with an inlet and two outlets is optionally provided downstream of the comminution pump, and one of the outlets is connected to the further outflow line and the other outlet is connected to the lower compartment (9) of the vacuum tank (1) via a return line (27).