Patent Publication Number: US-2023144334-A1

Title: Vacuum toilet and container body for a vacuum toilet

Description:
CROSS-REFERENCE TO FOREIGN PRIORITY APPLICATION 
     The present application claims the benefit under 35 U.S.C. §§ 119(b), 119(e), 120, and/or 365(c) of PCT/EP2021/057698 filed Mar. 25, 2021, which claims priority to Application DE 202020101760.8 filed Apr. 1, 2020. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a vacuum toilet and a container body for such a vacuum toilet. The vacuum toilet has a toilet bowl and a container body, for example a transfer tank with a first tank interior, and a flushing water tank with a second tank interior. The flush water tank is configured and connected such that flush water can be transferred from the flush water tank to the toilet bowl by means of an overpressure that can be applied in the flush water tank. The transfer tank is designed and connected in such a way that suction mass can be sucked out of the toilet bowl into the transfer tank with the aid of a negative pressure that can be applied in the transfer tank. 
     BACKGROUND OF THE INVENTION 
     Vacuum toilets are used, for example, as mobile toilets in vehicles (such as rail vehicles, aircraft, watercraft, buses, etc.) and offer the possibility of extracting suction mass from the toilet bowl with the aid of a vacuum and transferring it to a wastewater reservoir, e.g. a tank. 
     Such a vacuum toilet is known, for example, from EP 1 913 208 B1. The vacuum toilet comprises a seat, a bowl arranged thereunder, a pipeline and controlled valves for transporting suction mass from the bowl into a transfer tank and from there into a wastewater line. The vacuum toilet further comprises a flushing water tank from which rinse water can be transferred to the bowl. The transfer tank, flushing water tank, piping and valves are substantially located in the space below the seat. The manufacture of the transfer tank as well as the flushing water tank and their installation on the vacuum toilet are complex and cost-intensive. 
     It is therefore the object of the present invention to provide a vacuum toilet that is simple to manufacture and allows simplified assembly of the transfer tank and the flushing water tank. 
     According to the present invention, the transfer tank and the flushing water tank are formed by a container body having a partition with a first side and a second side facing away from the first side. The first side delimits the first tank interior of the transfer tank, and the second side delimits the second tank interior of the flushing water tank. In other words, the transfer tank and the flushing water tank are formed as a single component, for example by injection molding or rotational molding. However, other manufacturing processes are also conceivable. For example, the container body can be made of metal, in particular sheet metal, with individual pieces of metal or sheet metal being joined together in a sealing manner by means of welding. 
     In the context of the present invention, the term “suction mass” is understood to mean the mass removed from the toilet bowl during flushing thereof. The suction mass may contain flushing water as well as fecal matter and other components. 
     In the context of the present invention, the term “negative pressure” is further understood to mean a pressure that is lower than the atmospheric pressure at sea level, in particular lower than 1.013 bar. For example, a negative pressure is 0.5 bar to 1.013 bar. 
     In the context of the present invention, the term “overpressure” is understood to mean a pressure that is greater than atmospheric pressure at sea level, in particular greater than 1.013 bar. For example, an overpressure is 2 bar to 6 bar. 
     Preferably, the partition forms the flush water tank in the form of a truncated hollow cone, the flush water tank having a bottom with a first opening formed as a drain opening at a first end and having a second opening at a second end opposite the first end. For example, the drain opening is connected to the toilet bowl via a plurality of hoses so that flush water can be delivered from the flush water tank into the toilet bowl via a plurality of inlets in the toilet bowl. Preferably, the drain opening is located at the lowest point of the flush water tank to allow complete emptying of the flush water tank. Preferably, the flushing water tank is filled with such a quantity of flushing water that is sufficient for flushing the toilet bowl once. Alternatively, it is equally possible to dimension the flushing water tank in such a way that it can hold a quantity of water sufficient for multiple flushings of the toilet bowl. 
     SUMMARY OF THE INVENTION 
     In one embodiment of the present invention, the flushing water tank has a first inner diameter at its first end and a second inner diameter at its second end that is larger than the first inner diameter. The flushing water tank widens from the first inner diameter toward the second end to the second inner diameter. The second opening is circular and has an opening diameter equal to the second inner diameter of the flushing water tank. Preferably, the second opening extends over an entire end face of the hollow circular cylinder. Optionally, the flushing water tank has a demolding slope along which the flushing water tank expands. Preferably, the demolding slope is inclined by about 1° to 3° to a longitudinal axis of the flushing water tank. 
     In another embodiment of the present invention, the container body has an outer wall and the flushing water tank is connected at its second end to the outer wall such that the second opening of the flushing water tank is formed in the outer wall of the container body. This avoids undercuts in the flushing water tank. If the container body is manufactured, for example, by injection molding or rotational molding, this enables simple demolding of the container body from the mold. 
     Also preferably, the second opening of the flushing water tank is closed by a lid, the lid having an inlet opening for filling the flushing water tank with flushing water and a compressed air opening. Preferably, a float switch also protrudes through the lid, which senses the filling level in the flushing water tank and interrupts the supply of rinsing water through the supply opening when a desired filling quantity is reached. Optionally, the transition between the lid and the flushing water tank is sealed with the aid of a gasket. 
     In one embodiment of the present invention, the lid is configured as a mounting receptacle for mounting system components of the vacuum toilet. For example, such system components may be valves, connectors, hose lines or further electronic components such as ejectors or pumps. Preferably, the lid is made of metal so that a secure fastening is made possible. By designing the lid as a fastening receptacle, the system components can be fastened easily and quickly. For example, if the system components are a rinse water connection by means of which rinse water is filled into the flushing water tank, the length of hoses required to connect the rinse water connection to the flushing water tank is minimized. Optionally, the flushing water connection is connected directly to the flushing water tank so that no connecting hoses are required. 
     In another embodiment of the present invention, the drain opening of the flushing water tank is connected to a drain channel and the drain channel is connected to the outer wall of the container body such that a channel drain opening of the drain channel is formed in the outer wall. Preferably, the channel drain opening in the outer wall of the container body allows individual hoses to be connected to the flushing water tank. Preferably, this is achieved via a manifold connecting the channel drain opening to the individual hoses. The use of a drain channel enables the transfer tank to surround the flushing water tank on the one hand, but the flushing water to drain from the flushing water tank and be conveyed beyond the outer wall of the container body in the direction of the toilet bowl. 
     It is also preferred that the outer wall of the container body together with the partition wall and an outer wall of the drain channel form the transfer tank. The transfer tank and the rinse tank are separated from each other only by the partition wall. Preferably, a first portion of the partition wall forms the flushing water tank and a second portion of the partition wall together with the outer wall of the container body and the outer wall of the drain channel form the transfer tank. Preferably, the first and second parts are adjacent to each other in the longitudinal direction of the flushing water tank. 
     In a further embodiment of the present invention, the transfer tank is fluidically connected to the toilet bowl and is fluidically connectable to a wastewater reservoir. Preferably, a switchable valve is provided between the toilet bowl and the transfer tank and between the wastewater reservoir and the transfer tank, respectively. Thus, when the valve is open in the direction of the toilet bowl, suction mass can be sucked into the transfer tank by means of negative pressure and then, when the valve between the toilet bowl and transfer tank is closed but the valve is open in the direction of the wastewater reservoir, the suction mass can be conveyed into the wastewater reservoir with the aid of positive pressure in the transfer tank. 
     Preferably, the container body can be manufactured by rotational molding or injection molding. These processes allow simple production of complex geometries. 
     In another embodiment, the container body is made of polyethylene (PE), polyamide (PA) or polyvinylidene fluoird (PVDF). It has been shown that these materials are resistant in contact with suction mass, especially in contact with fecal matter. 
     The above-mentioned task is also solved by a container body having the features of protective claim  12 . The container body for a vacuum toilet comprises a transfer tank with a first tank interior and a flushing water tank with a second tank interior. The flushing water tank is designed and connected in such a way that flushing water can be conveyed from the flushing water tank into a toilet bowl of the vacuum toilet with the aid of an overpressure which can be applied in the flushing water tank. The transfer tank is designed and connected in such a way that suction mass can be sucked out of the toilet bowl into the transfer tank with the aid of a vacuum that can be applied in the transfer tank. The transfer tank and the flush water tank are formed by the container body, the container body having a partition with a first side and a second side facing away from the first side. The first side defines the first tank interior of the transfer tank, and the second side defines the second tank interior of the flushing water tank. The container body may be sold individually as a replacement part, for example, or produced as a contract manufacture fora manufacturer of vacuum toilets. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is explained below with reference to a preferred embodiment shown in the figures. The particular features illustrated therein may be used individually or in combination to provide preferred embodiments of the invention. The embodiment described is not a limitation on the generality of the subject matter defined in the claims. Showing: 
         FIG.  1    is a perspective view of a vacuum toilet with a container body; 
         FIG.  2    is a sectional view of the vacuum toilet with the container body according to  FIG.  1   ; and 
         FIG.  3    is a perspective view of the container body. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     A vacuum toilet  1  is described below with reference to  FIGS.  1 - 3   . The vacuum toilet  1  comprises a toilet bowl  2  and a container body  3  having an outer wall  4 . The container body  3  is made of polyethylene (PE) by rotational or injection molding. Alternatively, other materials may be used to make the container body  3  by rotational or injection molding, such as polyamide (PA) or polyvinylidene fluoird (PVDF). Optionally, the container body can also be made from sheets which are joined together in a sealing manner by means of welding. 
     The container body  3  forms a transfer tank  5  with a first tank interior  6  and a flushing water tank  7  with a second tank interior  8 . The container body  3  has a partition  9  with a first side  10  and a second side  11  facing away from the first side. The first side  10  delimits the first tank interior space  6  of the transfer tank  5  and the second side  11  delimits the second tank interior space  8  of the flushing water tank  7 . 
     The flushing water tank  7  is designed and connected in such a way that flushing water can be conveyed from the flushing water tank  7  into the toilet bowl  2  with the aid of an overpressure that can be applied in the flushing water tank  7 . The flushing water tank  7  has the shape of a hollow truncated cone and is formed by the partition wall  9  of the container body  3 . At a first end  12 , the flush water tank  7  has a bottom  13  with a first opening formed as a drain opening  14 . The drain opening  14  is arranged at the lowest point of the flushing water tank  7 . At a second end  15  opposite the first end  12 , the flushing water tank  7  has a second circular opening  16  with an opening diameter (D Öff ). 
     The flushing water tank  7  has a first inner diameter D 1  at its first end  12  and a second inner diameter D 2  at its second end  15 , which is larger than the first inner diameter D 1 . The flushing water tank  7  has a demolding slope  28  along which it widens from the first inner diameter D 1  in the direction of the second end  15  to the second inner diameter D 2 . The opening diameter (D Öff ) of the circular opening  16  corresponds to the second inner diameter D 2  at the second end  15  of the flushing water tank  7 . 
     The flushing water tank  7  is connected at its second end  15  to the outer wall  4  of the container body  3  in such a way that the second opening  16  of the flushing water tank  7  is formed in the outer wall  4  of the container body  3 . The flushing water tank  7  is thus completely open at its upper end face. The second opening  16  of the flushing water tank  7  is closed by a lid  17 . The lid  17  has an inlet opening (not shown) for filling the flushing water tank with rinsing water and a compressed air opening (not shown). A float switch  18  projects through the lid  17  into the flushing water tank  7 . A seal  19  is arranged between the lid  17  and the container body  3  to seal the connection between the lid  17  and the container body  3 . 
     The vacuum toilet  1  further comprises a plurality of system components, such as water and compressed air connections  20 , a control unit  21 , and an ejector  22 . The control unit  21  is adapted to control the ejector  22 . The ejector  22  is adapted to generate overpressures as well as underpressures in the flushing water tank  7  as well as in the transfer tank  5 . The overpressures in the transfer tank  5  can be about 2 bar. The overpressures in the flushing water tank  7  can be approx. 5 bar. The negative pressures in the transfer tank  5  are approx. 0.5 bar to 0.8 bar. The cover  17  is designed as a mounting receptacle for attaching the water and compressed air connections  20 . 
     The drain opening  14  of the flushing water tank  7  is connected to a drain channel  23 . The drain channel  23  has a channel drain opening  24  formed in the outer wall  4  of the container body  3 . 
     The transfer tank  5  of the vacuum toilet  1  has a first connection  25 , by means of which the transfer tank  5  can be fluidically connected to the toilet bowl  2 . The transfer tank  5  further comprises a second connection  26 , by which the transfer tank  5  is fluidically connectable to a waste water reservoir (not shown). The transfer tank  5  is formed by the outer wall of the container body  3  together with the partition  9  of the container body  3  and an outer wall  27  of the drain channel  23 . 
     In the following, the function of the vacuum toilet  1  is explained with reference to  FIGS.  1 - 3   . 
     Before using the vacuum toilet  1 , the flushing water tank  7  is filled with flushing water from a flushing water reservoir (not shown) via a water connection  20 . The filling takes place until the float switch  18  in the lid  17  of the flushing water tank  7  signals a predefined amount of flushing water present in the flushing water tank  7 . Preferably, the predefined amount of flushing water is sufficient for a single flushing of the toilet bowl  2 . Alternatively, it is also possible to dimension the flushing water tank  7  in such a way that it can hold a quantity of water that is sufficient for multiple flushes of the toilet bowl  2 . 
     If the toilet bowl  2  is to be flushed after use of the vacuum toilet  1 , this is communicated to the control unit  21  by pressing a switch (not shown) by the user of the vacuum toilet  1 . The control unit  21  then controls the ejector  22  in such a way that it generates an overpressure of approximately 5 bar in the flushing water tank  7  and thereby conveys the flushing water located in the flushing water tank  7  via the drain opening  14  of the flushing water tank  7 , the drain channel  23  and hoses connected thereto (not shown) into the toilet bowl  2 . 
     Then, the control unit  21  closes a first valve between the toilet bowl  2  and the first port  25  of the transfer tank  5  and a second valve between the second port  26  of the transfer tank  5  and a wastewater reservoir (not shown). 
     In a further step, the control unit  21  controls the ejector  22  in such a way that it generates a vacuum of approx. 0.5 bar to 0.8 bar in the transfer tank  5 . After the first valve is opened, the vacuum in the transfer tank  5  sucks off the aspirated mass in the toilet bowl  2  into the transfer tank  5 . 
     The first valve is then closed again by means of the control unit  21  and an overpressure of approx. 2 bar is generated in the intermediate tank in the transfer tank  5  via the ejector  22 . After opening the second valve, the extraction mass in transfer tank  5  flows into a wastewater reservoir connected to transfer tank  5 .