AU596023B2

AU596023B2 - Waste processing unit

Info

Publication number: AU596023B2
Application number: AU19049/88A
Authority: AU
Inventors: Daniel George McLennan
Original assignee: NORMAN WALSH
Current assignee: NORMAN WALSH
Priority date: 1984-10-24
Filing date: 1988-10-23
Publication date: 1990-04-12
Anticipated expiration: 2007-10-23
Also published as: AU1904988A

Description

j.

.I

V

C000 0 0 6 0~ C SOC 6 0~fl 0046 0 C SOC C SOC C 4 C 00CC. C

C

0*

CC

~.6 0 CC .6 501* 6 0CCt 6 00444.6 p 6 59.602 3-.

COMMONWEALTH OF AUSTRALIA The Patents Act 1952-1969 NORMAN WALSH Lot 2, Richardson Road,' STONEVILLE. W.A. 6554.

DANIEL GEORGE McLENNAN G.R. CULLEN COMPANY Dalgety House, 19 Eag16 -Street, BRISBANE-. Qid. Australia.

Name of Applicant: Address of Applicant: Actual Inventor(s): Address for service: CC 1-6 4 6 6 Cl COMPLETE PATENT SPECIFICATION FOR THE INVENTION ENTITLED: WASTE PROCESSING UNIT The following statement is a full description of the invention including the best method of performing it known to us: -i

-"I

H66 .T SUB-OFFI OCT 19O.1 ;bane G. Ahearn) '4 I ~LIIL I I L-~-L~LZi- :uLr i' n 00 04 0 0490 QQer ogo 04 0 04 o 00 'o 0 15 ~o 4 .o gO0 Do 0s go t o1 4 THE PRESENT INVENTION relates to a waste processing unit. In particular, the invention is directed to an anaerobic waste processing unit suitable for treating human waste from one or more toilets.

A waste digestion unit is disclosed in Australian Patent Application No. 20,890/83. Such a waste digestion unit is particularly suitable for small scale communal use, particularly in rural areas. One of the recognized problems of such a waste digestion unit is that undigested waste collects at the top surface of the waste mixture in the container and forms a crust.

This, in turn slows down the digestion of waste in the container. For this reason, the waste processing unit of Australian Patent Application No. 20,890/83 provides a stirrer assembly which is designed to break up the crust of undigested waste. However, the stirrer assembly increases the cost of construction of the waste digestion unit, and is difficult to remove for repair.

Moreover, the stirrer assembly is ineffective in those surface areas outside its range.

It is an object of the present invention to overcome, or substantially ameliorate the above describ-d disadvantages by providing an improved waste processing (or digestion) unit.

In one broad form, the present invention provides a waste processing unit of the type comprising a container having at least one waste inlet, and an i 2-

I-"

o an 0 0040 10 *r 4 4 4 44 0 4Q 44D 15 a 4( @4 4 1 outlet for digested waste, said waste inlet being below the level of waste in said container in use, said waste processing unit further comprising pump means adapted to recirculate liquid waste and effluent from the bottom region of the container over the top surface of the waste within the container.

Typically, the pump means comprises a manually operated plunger which pumps liquid waste and effluent from the bottom region of the container up through a vertical conduit to the top of the container and through a plurality of openings onto the top of the waste mixture. In this manner, the undigested waste at the top is kept moist and prevented from forming a hard crust. Unlike the prior art waste digestion unit which uses mechanical agitation of the undigested waste to break up the crust which is formed, the present invention uses a pump to irrigate the undigested waste to prevent the formation of a hard crust.

Preferably, the plunger has a flange or cap at the bottom thereof for agitating the waste and effluent at the bottom of the container to accelerate or enhance the digestion of the waste.

Notwithstanding other forms of the invention, a preferred embodiment thereof will now be described with reference to the accompanying drawings in which: Fig. 1 is a schematic sectional view of a waste processing unit according to the preferred 3 ~r L~1-i i l b .p embodiment; and Fig. 2 is a schematic sectional view of part of the plunger assembly of Fig. 1.

As shown in the drawings, the waste processing unit 10 of the preferred embodiment comprises a container 11 of cylindrical shape, typically having a cylindrical asbestos cement side wall, e.g. a length of asbestos cement pipe. The container 11 has a roof and floor which are circular and also of asbestos cement.

o~r oo. I10 The roof and floor are secured to opposite ends of the 9000 o side wall by any known suitable method.

The container 11 is provided with an inlet pipe o 4 12 which delivers human waste from one or more flush o toilet pans or urinals. Preferably, the inlet pipe 12 o II 15 is vented via vent 13. The container 11 is also provided with an outlet pipe 14, the outlet opening 00 being at the lower end of the container 11 but spaced above the floor. The outlet pipe 14 rises from the container outlet opening to a unit outlet at a higher level which determines the level of waste within the container. The unit outlet leads to a French drain, holding tank or the like. It is to be noted that the opening of the inlet pipe 12 into the container is below the level of waste within the container.

A vent 16 interconnects the top of the 4 0000 0 a 0000 0 s o a 00900 0 0 00 0 0 00 0 60 15 o oo a 0 0. 0 o a 0 0 0 S 09 0 0 00® 06

-'C

container to the riser portion of the outlet pipe 14 at a position below the unit outlet level. In other words, the volume in the container above the waste is liquid sealed. All openings into the container are also sealed to provide an anaerobic environment.

When operation of the unit is conenced, it will be filled with water to the level 24 of the unit outlet, i.e. until water starts to overflow from the unit outlet pipe 14 under gravity. Use of the toilet(s) or urinal(s) will then lead within a short time to the build up of population of anaerobic bacteria in the container 11, for anaerobic digestion of waste in the container. Waste will enter the container via the inlet pipe 12 and issue from the opening of the inlet pipe 12 to the container. Fresh waste will tend to float to the top of the waste level within the container. A spectrum of waste will develop over the depth of the container 11, with undigested waste at the top, fully digested waste at the bottom, and partially digested waste in between. Combustible gas will collect in the gas base above the level 24. Excess gas pressure is vented via pipe 16 through outlet pipe 14 and outlet vent 15. As undigested waste enters the container, fully digested waste will issue via the outlet opening near the bottom of the container through outlet pipe 14 to the unit outlet, and thereafter to a French drain, holding tank or the like.

5 An irrigating pump is provided to minimise the formation of a hard crust on the surface of the waste.

The irrigating pump comprises a vertical conduit 23 having an opening near the bottom of the container and a top opening communicating with a plurality of irrigation holes near the underside of the container roof. A plunger 17 extends through the conduit 23 and has a water piston arrangement at the bottom end thereof. The plunger also extends through the roof of the container 10 11, the top end being fashioned into a handle 18. A seal 19 is provided to seal' the closure of the opening in the container roof through which the plunger protrudes.

o" o The water piston is illustrated in more detail o, 15 in Fig. 2. It comprises a piston head 21 having a plurality of bores 24 therethrough. The plunger 17 is also surrounded by a loose fitting washer 22 located over the piston head 21.

When the plunger handle 18 is depressed, the piston head moves downwardly causing liquid to flow through the bores 22 and elevate the loose fitting washer 22. The washer 22 then sinks down to sit over the piston head 21. When the plunger handle 18 is elevated, the bores 24 are effectively sealed by the washer 22 and the piston head forces the water in the conduit above it up to the top of the conduit and out through the irrigation holes 26. The liquid then 6 irrigates the top surface of the waste, moistening the undigested waste to minimise the formation of a hard crust. Moreover, the moistening of the undigested waste tends to break it up and accelerate its digestion.

Openings 27 are provided in the conduit 23 above the piston head 21 to allow water to enter the conduit and be pumped to the surface.

In addition, the plunger 17 extends beyond and eaoR below the piston head 21 to terminate in a plunger plate o~o 1o 0 or flange 20 near the bottom of the container. Each time the plunger is raised and lowered, the plunger plate 20 agitates the effluent at the bottom of the tank to maximise the digestion of waste.

"o Preferably, the plunger 17 has a stroke of S 0@ S 15 approximately 300 mm. The plunger should be operated by raising and lowering at least once a day and preferably whenever a toilet or urinal is used. The waste should ar0 then be fully digested after approximately one and a @4 half days in the tank.

The present invention provides a robust, simple, inexpensive and trouble-free waste processing unit which is particularly, but not solely suitable for rural use. Digested waste issuing from the unit

I/

comprises a nutrient-rich aqueous solution suitable for agricultural use, a substantial proportion of potentially harmful organisms in the waste having been killed by the anaerobic operation of the unit.

-7

IJ

i l-nu~~ aY;oYix~umrr~- ,P-u too.

o 00 00 0

*OPP

099 o 00P 0 0 The foregoing describes only one embodiment of the invention, and modifications which are obvious to those skilled in the art may be made thereto without departing from the scope of the invention. For example, the manual plunger assembly can be replaced by a power actuated plunger or pump.

Although the waste processing unit of the present invention is particularly suitable for flush toilets, it can also be adapted for use with non-flush toilets if required.

094 09 .9 *0 S00 0 8 4 004 0 0 *9 9 so 9 .0 9 8

L

B

Claims

499.E 9999( 0 4t 99 B. si 4 THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:- 1. A waste processing unit of the type comprising a container having at least one waste inlet, and an outlet for digested waste, said waste inlet being below the level of waste in said container in use, said waste processing unit further comprising pump means adapted to recirculate liquid waste and effluent from the bottom region of the container over the top surface of the waste within the container. 2. A waste processing unit as defined in Claim 1 wherein said pump means comprises a manually operated plunger which pumps liquid waste and effluent from the bottom region of the container through a conduit to the top of the container and through a plurality of openings onto the top of the waste within said container. 3. A waste processing unit as defined in Claim 2, wherein the plunger has a flange or cap at the bottom thereof for agitating the waste and effluent at the bottom of the container to accelerate or enhance the digestion of the waste. 4. A waste processing unit as defined in any one of the preceding claims wherein said conduit extends through an upper wall of said container, said plunger being reciprocably slidable within said conduit, a piston head attached to said plunger such that reciprocation of said plunger within said conduit pumps waste into said conduit. A waste processing unit as defined in any one of 0999 O 9 9* 9990 9 94 9 9e 4 1 4 4; -II r 1 II the preceding claims whereii said piston is located above said flange or cap. 6. A waste processing unit as defined in any one of the preceding claims wherein said piston head includes a plurality of bores. A waste processing unit as defined in any one of the preceding claims wherein said conduit includes a plurality of openings located above said piston head. 8. A waste processing unit substantially as described with reference to the drawings. DATED this 23rd day of October, 1987. NORMAN WALSH By his Patent Attorneys G.R. CULLEN CO. ao.1 0 1 0 A 0a 0 0 6 ~0 0 0'~ 0 r, 141: