AU665202B2 - Processing of animal and poultry manure - Google Patents

Description

665202

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

C C Ct 11 DI 1C. L X6 UGO .NIG \IR O NjE Name of Applicant: Actual Inventor: DARRYL UGO JENNINGS GARRY GORDON JENNINGS 9 Cr St Address for Service: SHELSTON WATERS Clarence Street SYDNEY NSW 2000 "PROCESSING OF ANIMAL AND POULTRY MANURE" Invention Title: Details of Associated Provisional Application No. PL0191 dated 24/12/91 T e following statement is a full description of this invention, including the best method of performing it known to me/us:t 1 2 PROCESSING OF ANIMAL AND POULTRY MANURE *1 V Vr BACKGROUND OF THE INVENTION The present invention relates to the curing of animal and poultry manure to produce a product substantially free of pathogens.

It is known to compost manure, especially poultry manure, to produce a substance which may be used as a fertiliser or a feed stock for ruminant animals.

However, this process often gives rise to a product which although rich in nutrients is incompletely sterilised and so is often unsuitable for use as either a fertiliser or a feed stock. In particular, the live pathogens within the composted manure may pose a health hazard to persons handling it or livestock consuming it, and the shelf life may be unsatisfactorily short.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for curing animal and poultry manures to produce a product substantially free of pathogens which is cost-effective and avoids or at least ameliorates some of the disadvantages of the prior art.

Accordingly, in a first aspect of the invention, there is provided a method for producing a product substantially free of pathogens from animal and poultry manure, said method including the steps of: stockpiling manure having a moisture content of five to sixty percent for a first predetermined period in a substantially sealed enclosure to produce partially i

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'1 i~: i; r:i i;' :1 -3cured and densified manure, said substantially sealed enclosure including a gas o'tlet for effluent gases; collecting effluent gases from said gas outlet; heating said effluent gases to a temperature between 46°C and 210"C; and passing said heated gases through a bed of said partially cured and densified manure for a second predetermined period thereby to suspend the growth of pathogens and to produce a cured product.

Preferably the first predetermined period is not o. less than one week and the second predetermined period is not less than seven minutes.

Preferably, the substantially sealed enclosure includes a gas inlet for ambient air and the bed of 15 partially cured and densified manure is formed on a 9 perforated wire mesh conveyor.

Preferably also, the effluent gas which passes through the bed of partially cured and densified manure is filtered to remove solids, then injected into a 20 chamber under a bioactivated medium for absorption and consumption by micro-organisms.

The bioactivated medium used for the final treatment of the effluent gases may be implemented as a S"biogarden". This second aspect of the invention is applicable to the areas of public health and hygiene, horticulture, agriculture and industry. The second aspect of the invention provides a layer of porous aggregate in which is embedded a grid formation of 4-- -4perforated tubes, the porous aggregate lying upon an impermeable barrier. Above the porous aggregate, a porous lining is provided to physically separate the aggregate from an overlying biomass which supports plant life.

In use, effluent gases are ducted into the perforated tubes to pass into the aggregate and biomass.

The biomass and its resident plant life consumes nutrients in the effluent gases as well as nutrients generated from the effluent gases by natural micro-organisms within the biomass.

Preferably, the aggregate is kept moist by a commercial water supply apparatus, such as sprinklers, which supplements natural rainfall. Preferably also, the porous lining is provided by a non-corroding, non-biodegradable porous netting such as commercial shade cloth. The impermeable barrier is preferably concrete or plastic to prevent leakage of water and/or water table contamination. I 20 BRIEF DESCRIPTlON OF J'HE RAWINGS A preferred, embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 illustrates effluent gas management according to the first aspect of the present invention; Figure 2 illustrates solid product management according to the first aspect of the present invention; and .2 Li __l

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:i IIX-i 5 *9 ane Figure 3 illustrates, in side and end elevation the bioactivated medium according to a second aspect of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to Figure 1, manure with a moisture content of between 5% and 60% is blended and stockpiled in a large curing room 1. Handling is performed with the aid of a large four wheel drive commercial loader, shown schematically 2, which drives over the stockpile 3, compressing it into a block. This represents the first stage of curing and densifying. It will be appreciated that even in the absence of compression by the loader some densification will occur.

Unlike commercial composting systems, the method of the present invention substantially deprives the curing manure of oxygen. Where ambient air is supplied for the convenience of the loader operator, compacting of the manure reduces the exposure to atmospheric oxygen.

At this point the natural gases emanating from the curing manure include ammonia, carbon dioxide, oxygen, nitrogen, nitrous oxide and methane. These effluent gases, together with ambient air from the curing room are vented by means of an exhaust fan 5 to the curing machine 6 described below.

The venting of effluent gases creates a negative pressure in the curing room, helping to ensure that offensive odours do not escape into the atmosphere.

Sufficient ambient air is supplied to the curing room to 4::1 rJ, -6ensure safe and tolerable working conditions for the operator of the loader.

e the vented gases enter the curing machine 6, they are mixed, concentrated and passed through a flame burner 7 heating the mixture to between 46 0 C and 210 0

C.

The heated mixture is then pressurised and passed through a bed of product 8. The details of the bed of product will be described hereinafter with reference to Figure 2.

theI The pressurised gas mixture is passed through the i product for a period of not less than seven minutes in border to suspend the growth of harmful toxin producing pathogens and to remove excess moisture. Saturated gases are then removed from the curing machine and ducted 9 into an exculpation chamber 10 for removal of solids.

Once the solids are removed, the gas mixture is then repressurised and directed into a chamber 11 under a bioactivated medium 12, where micro-organisms consume and convert the gases into a non-offensive vapour 13 before venting to the atmosphere.

20 Parallel and complementary to the effluent gas treatment shown in Figure 1 and described above, the solid product preparation is shown in Figure 2. A minimum of one week after initial stockpiling, the semi-densified, partly cured product 3 is sliced, chopped and dumped into a commercial, continuous feeding hopper The product 21 then passes to a special screening sieve 22 for removal of impurities 23. The screen of the sieve is kept clear by means of a 7ushion of heated air -7- (not shown) between the screen and the (at this stage) "tacky" product.

From the screen, the "fluffed" product 24 is fed to a commercial densifying or globulising mill 25 and then to the curing machine 6.

As previously described, within the curing machine the effluent gases complete the curing of the product by suspending the growth of pathogens while allowing the multiplication of micro-organisms which are beneficial to plant growth and health.

At this point, the product is cured, densified and sterilised and may be used as fertiliser or a feed stock for ruminant animals. It remains only to be packaged with commercial packaging and/or bulk storage systems (not shown).

Referring now to Figure 3, a preferred embodiment of the second aspect of the invention is shown in both oo end and side elevation. The perforated grid 30 allows .effluent gases to escape into the aggregate 31 where the 20 gas is partially absorbed and retained by the moist particles of aggregate.

The effluent gases from the curing room previously described diffuse through the porous lining 32 to the 4 "next layer, the biomass 33. Plant life growing in the biomass consumes nutrients in the eifluent gases and fixes other components to form further nutrients.

Several levels of plant life give overlapping degrees of absorption through the foi7age. Grass 34, shrubs 35 and k I TI T 8 trees 36 as illustrated schematically in Figure 3, o provide a maximum degree of alorption. Moisture in the biomass and aggregate is controlled by a commercial garden watering system 37.

It will be understood by those skilled in the art that the method of the first aspect of the present invention, having been described with reference to specific examples, may be embodied in many other forms.

It will also be understood that, while the second aspect of the invention has been described with reference 0 to the treatment of effluent gases from the processing of animal and poultry manure, it is applicable to other forms of waste gas treatment. It will be appreciated that the size of the biogarden may be chosen 15 appropriately to the application and proportionally to the pressure of gas to be treated.

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Claims (9)

1. A method for producing a product substantially free of pathogens from animal and poultry manure, said method including the steps of: stockpiling manure having a moisture content of five to sixty percent for a first predetermined period in a substantially sealed enclosure to produce partially cured and densified manure, said substantially sealed enclosure including a gas outlet for effluent gases; collecting effluent gases from said gas outlet; heating said effluent gases to a temperature between 466C and 210 0 C; and passing said heated gases through a bed of said partially cured and densified manure for a second predetermined period thereby to suspend the growth of 15 pathogens and to produce a cured product.

2. A method as claimed in claim 1, wherein the first predetermined period is not less than one week and the second predetermined period is not less than seven minutes.

3. A method as claimed in claim 1 or claim 2, wherein the substantially sealed enclosure includes a gas inlet for ambient air.

4. A method as claimed in any one of the preceding claims, further including the step of forming a bed of partially cured and densifitd manure on a perforated wire mesh conveyo 'Aj ~I L1 il .i iI 10 A method as claimed in any one of the preceding claims, further including the step of filtering the heated gases, after they have passed through the bed of partially cured and densified manure, to remove solids.

6. A method as claimed in claim 5, further including the step of injecting said filtered heated gases into a chamber under a bioactivated medium for absorption and consumption by micro-organisms.

7. A method for absorbing effluent gases from the method of claim 1 including the steps of: providing a porous layer of aggregate upon an impermeable barrier; providing a layer of biomass above said aggregate layer; embedding a grid formation of perforated tubes within said aggregate layer; providing a porous lining to physically separate the aggregate layer from said overlying biomass layer; E ,t providing plant life within said biomass; providing moisture to said biomass layer and said aggregate layer; and passing said effluent gases into said grid formation of perforated tubes for absorption by said biomess.

8. A method as claimed in claim 7, wherein the biomass layer and aggregate layer are kept moist by the provision of a commercial water supply apparatus. A y W U I<r

9. A method as claimed in claim 8, wherein the wate-r supply apparatus is a sprinkler system. A method as claimed in any one of claims 7 to 9, wherein the porous lining is a non-corroding, non-biodegradable porous netting.

11. A method as claimed in claim 10, wherein the porous netting is shade cloth. Iv 1' DATED this 14th day of August, 1992 s R:Zr-GDQNJEN-NING FllTow Inttueof PaetAtony of Australia 4 t o SHESTONWATERS I III.. 12 i ABSTRACT A method for producing a substantially biologically inirt product from animal and poultry manures includes the steps of stockpiling manure having a moisture content between 5 and 60 percent for a predetermined period in a substantially sealed enclosure which has a gas outlet for effluent gases. The effluent gases are collected and heated to a temperature between 46°C and 210°C then passed through a bed of partially cured and densified i manure from the enclosure for a further predetermined period to suspend the growth of harmful pathogens and to produce a fully cured product. r1i 1&i-m