Toilet system with reduced or eliminated flushing requirement, especially for transportation vehicles

Abstract

A toilet system, especially for passenger transport vehicles, includes a toilet bowl connected via a suction valve and a waste collection pipe to a waste collection tank. Waste-contacting surfaces of the toilet system that come into contact with urine and fecal waste are coated with an adhesion-inhibiting or adhesion-reducing nanocoating. Thereby, the adhesion of waste to the toilet bowl and other components is significantly reduced, and the total flushing water demand can be substantially reduced or, preferably completely eliminated. An airflow flowing into the toilet bowl, induced by the vacuum suction through the suction valve, is sufficient to “flush” the waste material from the nanocoated waste-contacting surfaces. The toilet system provides a substantial reduction in the total system weight and in the required quantity of flushing water that must be carried in the vehicle, and thus makes the toilet system particularly applicable for passenger transport vehicles such as aircraft.

What is claimed is:  
     
         1 . A toilet system for collecting waste material including at least one of urine and feces, said system comprising: 
 a toilet bowl with a bowl outlet and a first waste-contacting surface adapted to come into contact with the waste material;    a waste discharge arrangement that is adapted to convey the waste material from said toilet bowl, and that includes a waste pipe connected to said bowl outlet and adapted to convey the waste material therethrough, a waste collection tank connected to said bowl outlet by said waste pipe and adapted to receive and collect the waste material therein, and a waste suction valve connected and interposed in said waste pipe between said bowl outlet and said waste collection tank, wherein at least one of said waste pipe, said waste collection tank and said waste suction valve has a second waste-contacting surface adapted to come into contact with the waste material; and    a suction source connected to said waste discharge arrangement and adapted to provide a suction airflow that flows into said toilet bowl from an outside environment outside of said toilet bowl, flows along said first waste-contacting surface, and flows out of said toilet bowl through said suction valve when said suction valve is open, such that said suction airflow assists in removing the waste material from said toilet bowl; and    wherein at least one of said toilet bowl and said waste discharge arrangement comprises a structural substrate and a nanocoating disposed directly or indirectly on said structural substrate so that said nanocoating forms at least one of said first waste-contacting surface and said second waste-contacting surface.    
     
     
         2 . The toilet system according to  claim 1 , further comprising an air jet arrangement that communicates from the outside environment outside of said toilet bowl into said toilet bowl and that is arranged and adapted to direct an air stream along said first waste-contacting surface.  
     
     
         3 . The toilet system according to  claim 2 , further comprising a toilet lid adapted to selectively close and open a top opening of said toilet bowl, wherein said air jet arrangement includes at least one air nozzle oriented to direct the air stream along said first waste-contacting surface.  
     
     
         4 . The toilet system according to  claim 2 , arranged and adapted so that the suction airflow through said suction valve drives the air stream from the outside environment through said air jet arrangement into said toilet bowl as at least a part of a totality of said airflow.  
     
     
         5 . The toilet system according to  claim 1 , wherein at least one of said waste pipe, said waste valve and said waste collection tank comprises said structural substrate and said nanocoating.  
     
     
         6 . The toilet system according to  claim 1 , wherein said toilet bowl comprises said structural substrate and said nanocoating, and wherein said first waste-contacting surface is at least a portion of an inner bowl surface of said toilet bowl.  
     
     
         7 . The toilet system according to  claim 6 , wherein said nanocoating is a thin film having a thickness in a nanometer range, and wherein said thin film has been formed by a nanotechnology process.  
     
     
         8 . The toilet system according to  claim 1 , expressly excluding all means of supplying a flushing liquid into said toilet bowl.  
     
     
         9 . The toilet system according to  claim 1 , further comprising a base layer arranged between said nanocoating and said structural substrate, so that said nanocoating is disposed indirectly on said structural substrate with said base layer therebetween.  
     
     
         10 . The toilet system according to  claim 1 , wherein said nanocoating is disposed directly on and in contact with said structural substrate.  
     
     
         11 . The toilet system according to  claim 1 , wherein said nanocoating consists essentially of a metal.  
     
     
         12 . The toilet system according to  claim 1 , wherein said nanocoating consists essentially of a polymer.  
     
     
         13 . The toilet system according to  claim 1 , wherein said nanocoating consists essentially of an element of the fourth group of the periodic table.  
     
     
         14 . The toilet system according to  claim 1 , wherein said nanocoating consists essentially of at least one element selected from the group consisting of Cr, Ti, Mn, Ni, Ta, Al, V, W, Co, Be, Zr, Hf, Nb, Mo, C, Si, Ge and Sn.  
     
     
         15 . The toilet system according to  claim 1 , wherein said nanocoating consists essentially of at least one metal carbide.  
     
     
         16 . The toilet system according to  claim 1 , wherein said nanocoating consists essentially of at least one of a metal nitride and a metal boride.  
     
     
         17 . The toilet system according to  claim 1 , wherein said nanocoating consists essentially of at least one compound having a covalent bonding property.  
     
     
         18 . The toilet system according to  claim 1 , wherein said nanocoating consists essentially of at least one compound having an ionic bonding property.  
     
     
         19 . The toilet system according to  claim 1 , wherein said nanocoating consists essentially of a sialon compound.  
     
     
         20 . The toilet system according to  claim 1 , wherein said nanocoating consists essentially of a nanocomposition of organic and inorganic components, and wherein said nanocomposition has a low surface energy.  
     
     
         21 . The toilet system according to  claim 1 , wherein said nanocoating has such a character that it provides a wetting angle of 0° to 10° with respect to a droplet of the waste material.  
     
     
         22 . The toilet system according to  claim 1 , wherein said structural substrate on which said nanocoating is disposed has a maximum substrate surface roughness of less than 100 nm and a mean substrate surface roughness of less than 10 nm.  
     
     
         23 . A toilet system for collecting waste material including at least one of feces and urine, comprising: 
 a toilet bowl comprising a bowl structure substrate, a bowl outlet, and a nanocoating that is provided on at least a portion of an inner bowl surface of said bowl structure substrate and that forms a first waste-contacting surface adapted to come into contact with the waste material;    a waste discharge arrangement that is adapted to convey the waste material from said toilet bowl, and that includes a waste pipe connected to said bowl outlet and adapted to convey the waste material therethrough, a waste collection tank connected to said bowl outlet by said waste pipe and adapted to receive and collect the waste material therein, and a waste suction valve connected and interposed in said waste pipe between said bowl outlet and said waste collection tank, wherein at least one of said waste pipe, said waste collection tank and said waste suction valve has a second waste-contacting surface adapted to come into contact with the waste material;    a suction source connected to said waste discharge arrangement and adapted to provide a suction airflow from said toilet bowl through said suction valve when said suction valve is open, such that said suction airflow assists in removing the waste material from said toilet bowl; and    air directing means that direct at least a portion of said airflow along said first waste-contacting surface downwardly toward said bowl outlet; and    expressly excluding all means of supplying a flushing liquid into said toilet bowl.