Integrated system marine sanitation device

A sanitation system, particularly for use in vehicles such as marine vessels (boats), trains, planes, etc. Into a holding tank with a sloping bottom containing sewage from a toilet system, such as a vacuum toilet system, about eight ounces of deodorant chemical is automatically injected into the tank approximately every 48 hours. This effectively controls odors while minimizing chemical consumption. A gas vent from the tank passes through a vent filter having a first type of activated charcoal effective against H.sub.2 S, and a minor amount of activated charcoal effective against amino acid gaseous compounds, the vent filter removing odors. A tank cap in the top of the cap supports "high" and "full" level indicator switches and allows for the injection of the chemical and the gas vent. A tank cleaning device comprising a piece of surgical tubing with a nozzle at its free end and connected to a source of liquid under pressure can also be utilized. In use, the nozzle impacts the tank walls while spraying liquid in it to effect cleaning. A control module and control panel provide for an indication of the tank liquid level, control of the injector pump, and control of the discharge pump which discharges sewage from the holding tank.

BACKGROUND AND SUMMARY OF THE INVENTION 
For many vehicles having toilet systems, particularly marine vessels, it is 
desirable to provide effective and relatively large holding capacity for 
the sewage, which may be ultimately legally discharged. Such tanks, 
however, typically have nauseating odors associated therewith, have 
breakdowns in equipment, and in general can be a nuisance that can render 
a very expensive craft unpleasant to operate. According to the present 
invention, a system, and individual component parts thereof, are provided 
which allow effective odor control of the holding tank over significant 
periods of time, to allow practical on-board retention until discharge is 
legally permissible, without odor problems. 
According to the present invention, a holding tank is provided with a gas 
vent in the top thereof through which odoriferous gases pass, such as--in 
particular--hydrogen sulfide and amino acid odors. An in-line filter, 
comprising a tubular housing with end terminations and retaining means 
adjacent each end for retaining activated carbon within the housing, is 
provided. The filter does not offer significant resistance to air flowing 
therethrough, and contains two different types of activated carbon, a 
first (about 90%) particularly effective against hydrogen sulfide, and a 
second particularly effective against amino acid gaseous compounds. 
Additionally, odor control chemical is injected into the tank. It has been 
found, according to the present invention, that maximum odor control with 
a minimum amount of chemical usage is provided when a small and 
predetermined amount of chemical is injected into the tank on a periodic 
basis. The chemical is injected after a significant amount of bacteria 
build-up but before exponential growth of the bacteria. A chemical 
injection pump remote from the tank provides for the injection. 
In order to facilitate odor control and tank discharge operations, a tank 
cap is provided in the top of the tank, the cap in removable sealing 
relationship with the tank top. The odor vent and chemical injection take 
place through the tank cap, and additionally the tank cap has operatively 
mounted thereon a pair of level indicator switches, such as "Reed" 
switches, one indicating a "high" level of liquid in the tank, and the 
other indicating that the tank is "full." The tank cap also can be 
provided for other purposes, such as allowing the passage of tank cleaning 
apparatus therethrough. The level switches are operatively connected to a 
control panel, which also controls the chemical injection, and controls 
the discharge pump. 
A discharge pump is operatively connected adjacent the bottom of the tank, 
at a point where a downwardly sloping bottom wall of the tank is at its 
nadir. A downwardly disposed flexible conduit loop connects the bottom 
portion of the tank to the discharge pump and an upwardly extending 
conduit loop connects the discharge pump to a nozzle discharge system 
which is below the waterline of a marine vessel. The top of the upwardly 
extending loop is at least a foot above the waterline of the vessel. 
The tank, hoses and other components are selected so that they do not pass 
odors. Such components, such as hoses that will not pass odors, may be 
purchased from SeaLand Technology, Inc., of Big Prairie, Ohio. 
A tank cleaning device which may be utilized according to the invention 
comprises a piece of flexible tubing, such as surgical tubing, connected 
at a first end thereof, to or adjacent a wall (preferably the top wall) of 
the tank and in communication with a source of fluid (preferably liquid) 
under high pressure. The free end of the tubing has a nozzle associated 
therewith, the nozzle having significant mass and also significantly 
restricting the flow of fluid therethrough and thereby increasing its 
velocity. The tube has sufficient length so that when fluid under pressure 
is supplied to the interior thereof, the tube will thrash wildly within 
the tank, and dispense fluid in the tank while the nozzle impacts against 
the tank walls. 
It is a primary object of the present invention to provide a vehicle toilet 
system holding tank assembly or the like that has excellent odor control. 
This and other objects of the invention will become clear from an 
inspection of the detailed detailed description of the invention, and from 
the appended claims.

DETAILED DESCRIPTION OF THE DRAWINGS 
An exemplary holding tank assembly according to the present invention is 
illustrated schematically in FIG. 1. The major components of the system 
include the holding tank 10, deodorant chemical container injection unit 
11, vent filter 12, discharge pump 13, a tank cap 14, a control module 15, 
and a control panel 16. The discharge conduit 17 from the toilets on the 
vehicle (in this case, a boat having a hull 18) with which the assembly is 
utilized passes into the tank 10, and an outlet conduit 19 is provided at 
the bottom of the tank. Preferably the bottom wall 20 of the tank slopes 
downwardly toward the discharge conduit 19 so that nothing accumulates and 
remains stagnant within the tank 10. 
The discharge pump 13, which may be of any suitable type but is preferably 
the type sold by SeaLand Technology, Inc. of Big Prairie, Ohio, and having 
a pump and a reciprocal pumping element connected the pump housing by a 
bellows or rolling diaphragm, is connected to the tank outlet 19 via a 
conduit having a downwardly extending loop--as indicated at 21 in FIG. 1. 
A discharge nozzle 22 passes through the hull 18 of the vessel below the 
waterline, and the discharge pump is connected to the discharge nozzle 22 
utilizing upwardly directed conduit loop 23. The very top portion of the 
loop 23 preferably is at least a foot higher than the waterline, and more 
desirably, at least two feet higher. The electrical control wires for 
operating the discharge pump 13 pass to the control module 15, which is 
connected to a source of electrical energy 24, and the control module 15, 
in turn, is connected to the control panel 16. 
A gas vent is provided in the holding tank 10 through the tank cap 14 at 
the top of the tank 10, and is connected via a 5/8" vent hose 25 to the 
vent filter 12 at one end thereof, the other end of the vent filter 12 
being connected to a vent fitting 26, which passes through the hull 18 
above the waterline. Deodorant chemical may be that sold under the 
trademark "WasteBeGone".TM. biodegradable deodorant with a detergent 
additive, sold by SeaLand Technology, Inc. of Big Prairie, Ohio. The 
chemical passes from the container/injection unit 11 through a 3/8" inside 
diameter hose 26' to the tank cap 14. 
Also provided on the tank cap 14 are first and second level indicators 27, 
28, respectively. The level indicators include cylindrical portions, such 
as the portion 29, extending downwardly from the tank cap 14 and 
containing a Reed switch therein. A float portion 30 moves up and down on 
the cylinder 29 in dependence upon the level of liquid in the tank 10, and 
the float 30 has a permanent magnet associated therewith for actuating the 
Reed switch. The electrical wires from the level controls 27, 28 pass 
through the tank cap 14 to the control module 15 and are controlled by the 
control panel 16. The wires for the injection control pump also pass 
through the control module 15 and are controlled by the panel 16. 
FIG. 2 illustrates a typical wiring diagram. Of course, a suitable timer is 
provided associated with the control module 15 for controlling periodic 
operation of the chemical injection pump 32 disposed in the unit 11. 
The control panel 16 is seen in FIG. 3. It includes a three-position switch 
34. When the switch 34 is in the central "off" position, both discharge 
pump 13 and the chemical injection pump 32 (controlled by a timer) are 
off. When it is in the "on" position, as illustrated in FIG. 3, then the 
deodorant injection system is activated and the pump 32 will be 
periodically activated to introduce a desired amount of chemical into the 
tank 10. An indicator light 35 indicates that the deodorant injection 
system is activated, and the light 36 indicates when an actual injection 
of deodorant chemical into the tank 10 is taking place. 
When the switch actuator 34 is in the righthandmost position, then the 
discharge pump 13 is on. The indicator light 37 indicates that the 
discharge pump 13 is working. Because the single switch 34 provides for 
deodorant injection and discharge pumping, it is impossible to have the 
mistaken situation where chemical is being injected while the discharge 
pump is running. 
Indicator 38 is responsive to float switch 27, and indicates that the level 
in the holding tank 10 is high. Indicator light 39 is responsive to float 
switch 28 and indicates that the tank is full and that discharge should be 
effected at the earliest opportunity. Another electrical switch 40, or the 
like, with associated indicator light 41, also may be provided for other 
functions, such as for a cleaning system for cleaning the inside of the 
tank. 
It has been found, according to the present invention, that optimum odor 
control with a minimum amount of use of deodorant chemical can be achieved 
when a predetermined amount of deodorant chemical is injected into the 
tank at predetermined time intervals. It is desirable to let the bacteria 
level build up somewhat before injecting the chemical, but not allow it to 
build up to the point where exponential growth occurs. It has been found 
effective to introduce between about 6-10 ounces of undiluted 
"WasteBeGone".TM. chemical into the tank 10 every 24 to 72 hours. An 
optimum has been found to be approximately an 8-ounce injection of 
chemical approximately every 48 hours. 
FIG. 4 illustrates the holding tank cap 14 and associated components. The 
cap comprises a cap body 42 having an exteriorally threaded collar 43 
depending therefrom, and which cooperates with an interiorally threaded 
portion in the top wall of the tank. A plurality of openings 44 through 46 
are provided through the body 42. For example, openings 44 and 46 can 
cooperate with an elbow, such as elbow 47, for connection to the vent 
filter 12 and chemical container/injection unit, respectively, while the 
electrical wires 48, 49 from the float switches 27, 28 pass through the 
opening 45. An 0-ring is disposed between the body 42 in the top wall of 
the tank 10 to provide a sealing engagement of the tank cap 14 to the tank 
10. Other passageways may be provided in the tank cap 14 for other 
devices. 
For tanks that do not have interiorally threaded openings in the top 
thereof, the adaptor flange 51 of FIG. 5 may be utilized. The flange 51 
includes an interior internally threaded portion 52 and smooth, exterior 
collar 53, which can pass through the circular opening in the top of the 
tank 10. A gasket 54 is provided between the flange 51 and the top of 
tank, with fasteners 55 passing through aligned openings in the flange 51 
and the gasket 54 for holding a structure onto the top of the tank. 
The vent filter 12 is shown in detail in FIGS. 6 through 10, and includes a 
tubular housing 60 having PVC end caps 61, 62, respectively connected to 
the tank 10 and the hull vent fitting 26. Details of the PVC end cap 62 
are illustrated in FIG. 9, cap 62 having interior 3/4" pipe threads 63, 
which are connectable to an exteriorially threaded connection 64 (see FIG. 
6) for ultimate connection to the conduit leading to fitting 26. The 
housing 60 typically would be elongated so that it had a length of about 
14", with a minimum length of about 8", and the housing 60 preferably is 
of PVC pipe, with end caps 61, 62 solvent bonded thereto. The PVC pipe 
forming the housing 60 preferably has a diameter of about 11/2". 
Within the tubular housing 60 at each end thereof is a retaining means for 
holding activated carbon 65 (FIG. 9) within the housing. The retaining 
means comprises a piece of open-cell foam 66 which actually engages the 
activated carbon 65, and an apertured first, retaining polypropylene 
element 67. An end view of the element 67 is seen in FIG. 10, including 
the large apertures 68 therein. Preferably, the activated carbon 65 is 
composed of two different types, a first type, comprising a majority of 
the activated carbon (e.g., about 90%), which is particularly effective 
against hydrogen sulfide , and a second type, which is particularly 
effective against amino acid gaseous components. Both types may be 
purchased commercially from Calgon, or other sources. The housing 60 has 
sufficient cross-sectional area and the retaining means 66, 67 are 
constructed with sufficient porosity so that the filter 12 does not offer 
significant resistance to air flowing therethrough, but rather removes 
odors from the air before they are vented through fitting 26. 
One particularly useful way that the housing 60 can be oriented and mounted 
for a wide variety of environments is by utilizing the bracket 70 
illustrated in FIGS. 7 and 8. The bracket 70 preferably comprises an 
integral piece of wire having opposed side portions 71, 72, which are 
spaced apart from each other in a manner such that they are normally 
spaced apart a distance slightly less than the diameter of the housing 60, 
and therefore when the housing 60 is moved into contact therewith, they 
are deflected outwardly and clamp the housing in place, as illustrated in 
FIG. 7. The bracket 70 also includes elongated sections 73 connecting the 
side portions 71, 72, and fastener-receiving loop forming portions 74, 75 
between the side portions 71, 72, respectively, for receiving screw 
fasteners 76 or the like to mount the bracket 70 to another surface, such 
as deck or bulkhead surface 77 (see FIG. 8). 
It is also desirable, in order to effect maximum odor control, to be able 
to periodically clean out the holding tank. A tank or container interior 
cleaning system according to the invention is illustrated in FIGS. 11 and 
12, shown in association with a tank or container 80 having interior walls 
including side walls, a bottom wall, and a top. Preferably, a cap 81, 
comparable to the tank cap 14, is disposed in the top wall of the 
container 80 and includes a hollow fitting 82 to which a flexible tube 83 
is connected at a first end thereof using a conventional hose clamp 84. 
The flexible tube 83 also has a second, free end 85 thereof. The tube 84 
may be formed of any flexible material, such as surgical tubing. At the 
second end 85 thereof, a nozzle is provided, indicated by reference 
numeral 86. The nozzle adds mass to the free end 85 of the tubing 83, and 
preferably is of metal, hard plastic, or the like. The nozzle is clamped 
solidly to the free end of the tube, as by barbs extending from the nozzle 
86 into the tube material (not shown) and/or with a wire clamp 87. The 
nozzle 86 includes a flow restricting portion or orifice 88, which 
significantly restricts the flow of liquid through the nozzle 83, thereby 
increasing its velocity. The tubing 83 is connected, through cap 81, to a 
source 89 of liquid (e.g., a cleaning liquid) or other fluid under high 
pressure. 
When liquid under high pressure is supplied to the interior of the tubing 
83, tubing 83 thrashes wildly about the interior of the container 80 (as 
indicated in dotted line in FIG. 11), dispensing liquid throughout the 
interior of the container 80, with the nozzle 86 at the free end 85 
thereof impacting at least the side walls of the container 80 to 
facilitate the cleaning action. Note that the hose 83 has sufficient 
length within the container 80 so that the nozzle 86 can impact at least 
the side walls of the container 80, and in fact it is desirable for the 
tube 83 (though not shown in FIG. 11) to have a length greater than the 
distance between the cap 81 and the bottom of the container 80. 
It will thus be seen that according to the present invention an effective 
odor control system and procedure for toilet systems associated with 
vehicles (particularly boats, planes and trains or the like) is provided. 
While the invention has been herein shown and described in what is 
presently conceived to be the most practical and preferred embodiment 
thereof, it will be apparent to those of ordinary skill in the art that 
many modifications may be made thereof within the scope of the invention, 
which scope is to be accorded the broadest interpretation of the appended 
claims so as to encompass all equivalent structures, methods, and devices.