WO1994007358A1

WO1994007358A1 - Flushing systems

Info

Publication number: WO1994007358A1
Application number: PCT/AU1993/000501
Authority: WO
Inventors: Ian Robert Jones; Donald Matthew Mcleish
Original assignee: Stockyard Industries Pty. Ltd.
Priority date: 1992-10-06
Filing date: 1993-09-30
Publication date: 1994-04-14
Also published as: AU3994493A; AU662057B2

Abstract

A flushing system (10) including: (i) a plurality of flushing channels (11) located in a livestock shed or barn (12); (ii) a suspended floor (38) for supporting animals (53) located above the floor (38) which has a plurality of apertures (37, 62) whereby faeces, animal feed, urine and other animal detritus may fall and thus be deposited in said plurality of flushing channels (11); (iii) conduit means (14) whereby water is transported to each flushing channel (11); and (iv) valve means (30) for controlling water flow through each flushing channel (11) selectively.

Description

TITLE FLUSHING SYSTEMS FIELD OF INVENTION THIS INVENTION relates to flushing systems for use with livestock pens which may be used in piggeries, cattle pens, horse stables, goat pens and the like.

BACKGROUND ART It is well known in relation to piggeries or hog barns to provide a f.ooring system comprising steel or wooden members which are arranged in spaced parallel positions so as to define slots through which droppings inclusive of faeces and other waste material can pass. However, the animal droppings had a severe deleterious effect on the steel or wooden members causing corrosion of steel members and rotting of wooden members. Also a further problem was caused by bacteria growing on the wooden flooring members in the moist environment of a piggery with subsequent risks to animal health. The use of steel flooring members had a further disadvantage of rapidly conducting heat away from animals which can be deleterious to the health of young animals in particular in cold climates. In U.S. Patent 4,329,939 reference is made to a flooring system comprising spaced wooden beams extending transversely of an animal pen which beams support a plurality of flooring units or tiles which are a one piece plastics moulding which have relatively high heat insulating properties and which are unaffected by animal droppings. The tiles were generally rectangular and included a plurality of longitudinal slots. Each tile also included a tread surface comprising upstanding ribs. There was also provided reinforcing ribs on the underside of each tile. The droppings from the animals fell through the slots and onto a base floor usually formed from concrete.

Reference also may be made to slotted flooring for use in animal husbandry which is discussed in US Patent 4,048,960 having a plurality of elongate aluminium floor lengths with longitudinally spaced slots as well as transversely spaced slots wherein each length was provided with a multiplicity of integral vertical support beams. One longitudinal side of a slotted floor length was provided with a male connector part which engaged in a female connector part of an adjacent floor length.

Reference also may be made to French Patent 2,490,071 and German Patent 3030854 which concerns similar subject matter. Reference may also be made to US Patents 492777, 2856897 and 4953501 as well as German Patents 2812008, 3244732 and 3204754 as well as UK Patent 2248076 which serves as background state of the art.

One marked disadvantage of the abovementioned prior art was that while provision was made for animal droppings or faeces to fall onto a base floor below the slotted upper floor or suspended floor supported by the spaced floor beams there was no mention in these specifications as to the means of disposal of the faeces.

There have been many traditional methods in which the faeces has been removed in the past especially in regard to adoption of a suspended slotted or perforated floor above a base floor especially whereby spaced floor beams were not utilised. One method adopted the provision of a deep wide area under the suspended floor wherein the faeces and other detritus were shovelled from the deep wide area to an adjacent location such as a collection trench by hand. Alternatively the faeces and other detritus were pushed out of the deep wide area by a small tractor or in other cases by a circulating chain which was used as a scraper.

In later years the faeces have been removed hydraulically whereby in one hydraulic method the solid base floor was formed as a closed catchment which was half filled with water. As the animals defecate, drink and urinate above the base floor the catchment generally filled with detritus and thereby quantities of ammonia, hydrogen sulphide and other noxious and corrosive combinations of gases were produced. When the catchment area was filled with water, a gate at one end thereof was opened and the resulting huge mass of putrefying material was then transferred to a dam or other collection location which resulted in a horrendous odour which was not appreciated by neighbours or workers at the piggery. In this regard it had to be realised that very corrosive and odoriferous gases were released and that such gases were released often inside a piggery building or hog barn which often resulted in suffocation to people present in the building or hog barn.

Another hydraulic method was the provision of an oxidation trench in the form of an elliptically shaped trough underneath the slotted or perforated suspended floor supporting the animals having a central laneway. There was also provided a paddle wheel or beater to push the material around the periphery of the building in an elliptical flow wherein the material was entrained with water. The relevant theory was that it was necessary to keep the detritus under constant agitation and also to keep the material oxygenated. However huge amounts of energy are required to carry out this task effectively. One of the problems of this hydraulic method was that any solids that come in through the faeces are dropped onto the floor of the oxidation ditch and gradually a sediment bed was created which has to be removed by shovel. This was not an easy task because of the slotted or perforated flooring above the trench. The speed of the water travelling in the oxidation ditch was slow and of the order of 0.1 - 0.2 metres per second. Another hydraulic method which has been utilised was to provide a tipping bucket whereby water can be released and thereby race down a fairly wide channel between transversely spaced beams supporting the suspended flooring and remove deposited material to the other end. This was conceivably the only flushing method that would have worked in relation to the prior art discussed above especially in relation to US Patent 4,329,939.

BROAD STATEMENT OF INVENTION It therefore is an object of the invention to provide a flushing system for piggeries and the like which may alleviate the abovementioned difficulties associated with the prior art.

Another object of the invention is to provide a method of flushing piggeries and the like to remove faeces and other detritus which also may alleviate the abovementioned difficulties associated with the prior art.

The flushing system of the invention includes - (i) a plurality of flushing channels located in a livestock shed or barn;

(ii) a suspended floor for supporting animals located above the floor which has a plurality of apertures whereby faeces, animal feed, urine and other animal detritus may fall and thus be deposited in said plurality of flushing channels; (iii) conduit means whereby water is transported to each flushing channel; and (iv) valve means for controlling water flow through each flushing channel selectively. There also may be provided a receiving tank for receiving water flushed from each flushing channel entrained with animal detritus.

There also may be provided pump means for pumping water from the receiving tank to a treatment location through a transfer conduit.

The flushing system of the invention may also include a return conduit whereby water may be recycled from the treatment location to an inlet tank in fluid communication with said conduit means.

The flushing method of the invention may also include the following steps:

(i) passing water from conduit means on a controlled basis through a plurality of flushing channels in the form of a full width stream of water and at a velocity sufficient to maintain faeces, urine and other animal detritus as a suspension to thereby flush said animal detritus from each flushing channel; and (ii) collecting water entrained with said animal detritus after passage through each of the flushing channels for ultimate disposal. Preferably there is included a step (iii) wherein water collected in step (ii) is passed to a receiving tank and a further step (iv) wherein said water is transferred under pressure from said receiving tank to a treatment location.

Preferably there is further included a step (v) whereby treated water is recycled from the treatment location to a header tank which is in fluid communication with said conduit means.

In relation to the flushing system of the invention each flushing channel may have any suitable cross-sectional shape which is suitably square or rectangular. It is highly desirable that the maximum width or transverse dimension of each flushing channel by 500 mm and that the minimum width or transverse dimension of each flushing channel be 150 mm. Preferably each flushing channel has an optimum width or transverse dimension of 300-400 mm and more suitably 400 mm. The height of each flushing channel is not critical but may be of the order of 100-300 mm and more suitably 200 mm. The slope of each flushing channel to the horizontal may be of the order of 0-6 mm.

The suspended floor may be of any suitable construction and for example may be of the same structure embodied in US Patent 4,329,939 or US Patent 4,048,960 discussed above. Preferably however a base structure of the suspended floor is formed from a plurality of structural blocks placed in end to end relationship. However such structural blocks may be replaced by elongate beams if desired. However, it will be appreciated that such beams are suitably formed from concrete or plastics material to avoid corrosion from the animal detritus. To this end steel reinforcing is preferably avoided.

The base structure of the suspended floor may support a plurality of tiles or blocks which are again suitably formed from plastics or concrete. However metal tiles may be utilised which may be formed from corrosion resistant material such as expanded metal, perforated metal sheet, woven wire or welded wire. The tiles may be laid transversely across a pair of spaced rows of structural blocks in side by side and abutting relationship. If concrete tiles are used then they may include one or more elongate slots.

Releasable attachment means may be utilised between adjacent tiles such as a plug socket interconnection but is not believed essential.

The base floor for supporting the suspended floor may be of any suitable construction such as concrete.

The conduit means for supplying flushing water to each flushing channel may be of any suitable type. In one form a plurality of flow conduits may be arranged so that each flow conduit may comprise an extension of an adjacent flushing channel. Each flow conduit may also be provided with valve means so as to control flow of water into an adjacent flushing channel. Each flow conduit may also be connected to a common manifold.

However more preferably there is provided a manifold conduit which is provided with a plurality of valves at spaced intervals along the length of manifold conduit whereby each valve is located adjacent an associated flushing channel.

There also is provided a receiving or collection tank for receiving water flushed through each flushing channel which is entrained with the animal detritus. The receiving tank may also be provided with a submerged pump for pumping waste water from the receiving tank to a treatment location wherein the waste water may be treated biologically and/or using suitable filtration means to provide treated water which may be used for flushing purposes.

The treated water may then be recycled to a header tank which is in fluid communication with the conduit means associated with the flushing channels. In this regard the inlet tank may be provided with a float valve for ensuring that treated water may flow to the conduit means only after achievement of a height in the inlet tank.

BRIEF DESCRIPTION OF THE DRAWINGS Reference may now be made to a preferred embodiment of the invention as shown in the attached drawings wherein -

FIG 1 is a perspective view of a flushing system constructed in accordance with the invention; FIG 2 is a side elevation of the flushing system referred to in FIG 1 ; FIG 2A is a detailed view of the float valve used in the header tank shown in FIG 2;

FIG 3 is a plan view of the flushing system shown in FIG 1 ; FIG 4 is a perspective of the flushing channels and associated conduit means;

FIG 5 is a front view of the flushing channels shown in FIG 4;

FIG 6 is a perspective view of the underside of a plastics tile use with the flushing system shown in FIG 1 ;

FIG 7 is a side view of the plastics tile shown in FIG 6;

FIG 8 is a plan view of the plastics tile shown in FIG 6.

FIGS 9 and 9A are views showing an operative and inoperative position of a float valve different to that shown in FIGS 2 and 2A;

FIGS 10, 11 and 12 are perspective views of different types of valves that may be used for controlling water flow in each flushing channel; and

FIG 13 is a perspective view similar to FIG 4 but showing the valve means from a different orientation. BEST METHOD FOR CARRYING OUT THE INVENTION In relation to the flushing system 10 shown in FIG 1 , there are provided a plurality of flushing channels 11 that extend outwardly beyond the end of a building or shed 12 at each end of the building 12. At one end 13 of the building the flushing channels 11 are connected to a common manifold 14 which is in fluid communication with a header tank 15 having float valve assembly 16. Water 17 is contained in header tank 15 and flows through manifold 14 for flushing out channels 11. There is also provided conduit 18 interconnecting header tank 15 with water treatment lagoon 19. Water after being flushed through flushing channels 11 in shed 12 is then collected in collection ditch or trench 20 located outwardly of end 20A of shed 12 whereby water will flow to tank 21 located below ground level 24. Tank 21 contains pump 22 which pumps water through conduit 23 to treatment lagoon 19.

In FIG 2 the float valve assembly 16 includes ball 25, support arm 26 and valve body 27 located adjacent to side wall 28 of tank 15 which is in fluid communication with inlet conduit 18. Flow valves 30 are shown mounted to manifold 14 to regulate the amount of water being flushed through flushing channels 11. Branches 31 of collection ditch 20 extend into associated flushing channels 11 as shown. FIG 2A shows the operation of float valve assembly 16 wherein support arm 26 is pivoted at 26A to valve body 27. An inoperative position of support arm 26 is shown in full outline and an operative position shown in phantom. When the water level is less than the desired height shown in FIG 2 support arm 26 may pivot to the operative position resulting in elevation of valve stem 26B and associated sealing member 26C from engagement with valve orifice 26D and thus allowing water to enter tank 21 through inlet conduit 18 and subsequently through internal bore 26E of valve body 27 as shown by the arrow in full outline.

FIG 3 shows a plan view of this arrangement.

In FIG 4 a more detailed view is shown of the inlets 32 of flushing channels 11. Manifold 14 is indicated as abutting riser blocks 33 which are aligned in end to end relationship as shown in FIG 4 and abut at 34. Rows 35 of riser blocks 33 are shown and such rows form the boundaries of an individual flushing channel 11 as indicated. There is also shown concrete tiles 36 having internal slots 37 which form one type of suspended floor 38 which is located above base floor 39 which is normally formed from concrete. Tiles 36 also include enlarged end portions 40 to facilitate mounting to an adjacent row 35 of riser blocks 33. Each of the concrete tiles 36 are oriented in side by side relationship as shown in FIG 4 and abut at 41. As well as abutting at 41A with an adjacent concrete tile 36 associated with an adjoining channel 11.

Gate valve assembly 30 includes an inlet 42 and outlet 43 and valve body 44. Inlet 42 is shown mounted in an associated aperture 45 of manifold 14 and outlet 43 has an extension conduit 46 attached thereto at 47. Gate valve assembly 30 also includes actuating handle 48, valve stem 49 and valve member or gate 50 which may prevent flow through valve bore 51 when required. It will also be noted that an access space 52 is created for access to valve assemblies 30 wherein the concrete tiles 36 are spaced from manifold 14. In FIG 5 pigs 53 are shown on suspended floor 38A which in this case comprises plastics tiles 53 illustrated in more detail in FIGS 6-8. Faeces drop through apertures 54 shown in FIGS 6-8 in plastics tiles 53 to base floor 39. Also shown is adjacent wall 55 of shed 12 supporting flushing channels 11 wherein a ledge 56 supports tile 54 at 57. Base floor 39 comprises a layer of concrete 58 as shown on ground 24.

Tiles 53 are shown in more detail in FIGS 6-8 and include end portions 59 having hollows 60 separated by partitions 61 , a plurality of apertures 62 and reinforcement ribs 63 oriented diagonally as shown with associated support rods 64. There is also shown locating dowels 65 which may engage an associated recess 66 in an adjoining plastics tile 53 when required. Apertures 62 are of conical shape as indicated in phantom in FIG 7. There is also provided upper surface 67 as well as end walls 68 and side walls 69. Also shown are inner walls 70.

FIGS 9 and 9A show the operation of a float valve assembly 71 different in construction to float valve assembly 16 shown in FIGS 2 and 2A. Inlet conduit 72 in the form of a flexible hose is attached to header tank 15 at 73 and has an inner end 74 subject to the operation of a needle valve 75 which is attached to support arm 77 which is pivoted at 79 to bracket 78A attached to side wall 78 of header tank 15. Support arm 78 carries float member 80. The operative position of the valve assembly 71 is shown in FIG 9 when the height of water 81 is less than the desired or usual height shown in FIG 9A. In the position shown in FIG 9 support arm 77 pivots downwardly thereby moving needle valve 75 away from inner end 74 of hose 72 allowing water to enter header tank 15 as shown in FIG 9. Also shown is manifold 14.

FIGS 10, 11 and 12 show the construction of a gate valve, butterfly valve and ball valve which may be used as various forms of flow control valve 30. The gate valve shown in FIG 10 has already been described in some detail in FIG 4. An additional component shown is nut 82 of handle 48. FIG 11 shows butterfly valve 83 having handle 84 which is attached to boss 85 and associated sleeve 86 which contains valve stem 87 and attached valve member 88. Upon movement of handle 84 valve member 88 may move to from a vertical plane shown in full outline to a vertical plane aligned with the longitudinal axis of the valve bore formed by inlet 42 and outlet 43 and thus allow water flow to occur from inlet 42 to outlet 43. Valve stem 87 is attached to valve body 87A at 88A. In FIG 12 ball valve 89 is shown having handle 90 which is attached to boss 91 and support member 92 which is attached to ball 93 having hollow passage 94. When pivoted from a closed position shown in FIG 12 to an open position passage 94 may thereby allow inlet 42 to communicate with outlet 43. Ball 93 is attached to valve body 95 in a lower position at 96. FIG 13 shows the location of float valve 30 from a different view to that shown in FIG 4 with two tiles 36 removed for convenience to illustrate gate valve 30. Longitudinal beams 97 may be utilised in substitution of riser blocks 33 and manifold 14 is shown abutting beams 97 at 98.

In operation of the flushing system of the invention when designing a piggery or livestock building 12 it is usually necessary to calculate the approximate load of faeces which will be dropped on to floor 39 over a certain period of time eg. a year. This can be worked out from the number of pigs which may be produced each year which also includes the number of sows which may be produced. For example, sows normally have 2 litters per year and 10 pigs per litter. Pig populations normally comprise (a) breeding animals or sows, (b) farrowing animals or animals giving birth, (c) weaners and (d) growing animals. The requirements of these four different types of pigs are different and for example in relation to breeding animals they are normally kept in individual pens or crates. In relation to farrowing animals they are normally kept whereby the mother pig is kept separated from the piglets and wherein the piglets may communicate with each other in different pens. One manner of achieving this is to retain the mother pig in a high walled pen. , Weaners and growing animals are usually retained 15-20 per pen.

In relation to food intake it usually also is necessary to calculate the amount of food required to maintain a certain number of pigs and this may be calculated on the basis that breeding pigs eat 2 kg of feed per day, farrowing animals eat 4-5 kg of feed per day, weaners eat 1-2 kg of feed per day and growing animals eat 2-3 kg per day.

From the relevant food intake it therefore is possible to calculate the load required to maintain the pigs over a relevant time interval and the flooring system utilised for the pigs may be constructed having regard to the value of the load.

In accordance with the invention the piggery is constructed on the premise that no hand cleaning at all is to be carried out. Pigs are social animals and tend to defecate in one area of the pen and socialise in another.

From the load therefore can be calculated the amount of water required to clean the flushing channels 11.

In order to achieve this objective the valve assemblies 30 are required to be opened for a period of 20-60 sec each day based on the calculation of the amount of water required to shift the load deposited into flushing channels 11. This also can be calculated from the level of water in the header tank 15 and also how much water will be required to flow through a valve orifice of a given size. In practice some channels 11 may require more flushing than other channels and therefore the flushing operation may be repeated if necessary.

The diameter of manifold 14 is suitably substantially greater (ie. 2:1 or 3:1 for example) greater than the diameter of valve passage or orifice 51. Also it is important to stress that valve assemblies 30 are opened individually and that usually an array of 10 valve assemblies 30 is required to be opened and closed at one time.

The height of each flushing channel 11 is suitably 800 m but this parameter is not critical in relation to operation of the flushing system of the invention. Also from elementary physics it can be deduced that water needs to flow about 1 metre per second to keep normal solids in suspension. This therefore is the preferred speed of water flows through each of the flushing channels. In the context of the invention the solids that have to be removed include faeces, spilt animal feed, bone fragments and any reaction product of feed and faeces.

The flushing channels are aligned with the length of the building so that there are no real constraints on the length of the building. Suitably each flushing channel may be sloped and from a set of mathematical tables or other criteria the relevant flow rates can be calculated to efficiently remove the animal detritus from each flushing channel.

So in relation to designing a particular flushing system in accordance with the invention that may be required, the load that has to be removed from the flushing channels can be calculated based on the number of animals as described above. This means that each flushing channel should be flushed per day or other suitable period of time. Also the putrefaction should occur outside the confines of the building to overcome some of the problems of the prior art as discussed above.

The valve means that may be utilised in relation to each flushing channel may be of any suitable type. Thus gate valves, bufferfly valves, spool valves or any valve having a movable valve member which in the closed position prevents water flow through a valve body may be utilised.

The valves may also be actuated manually or automatically and such actuation may be carried out mechanically, hydraulically, pneumatically or any other suitable means.

Suitably the concrete tiles 36 described above are of dimension 395 x 200 x 100 mm. The slot size may be between 10 mm width in the case of baby pigs to 25 mm width in the case of adult pigs. The top surface is suitably non skid so that some knurling may be appropriate but suitably is not abrasive. Slotted concrete tiles, slotted plastics tiles and solid riser blocks may be provided in any suitable combination as may be required.

The mode of action of the water in flushing animal detritus from flushing channels 11 is by the creation of a full width stream of water dictated by the relatively narrow width of each channel which engulfs all animal detritus in its wake as it flows down flushing channels 11. This prevents the water from skirting around heaps of animal detritus that would occur if the flushing channels were relatively wide as indicated in the prior art.

Claims

CLAIMS :

1. The flushing system of the invention includes - (i) a plurality of flushing channels located in a livestock shed or barn; (ii) a suspended floor for supporting animals located above the floor which has a plurality of apertures whereby faeces, animal feed, urine and other animal detritus may fall and thus be deposited in said plurality of flushing channels;

(iii) conduit means whereby water is transported to each flushing channel; and (iv) valve means for controlling water flow through each flushing channel selectively.

2. A flushing system as claimed in claim 1 wherein there is further provided a receiving tank for receiving water flushed from each flushing channel entrained with animal detritus.

3. A flushing system as claimed in claim 2 further including pump means in the receiving tank for pumping water to a treatment location through a transfer conduit.

4. A flushing system as claimed in claim 1 further including a return conduit and a header tank whereby water may be recycled from the treatment location to the header tank which is in fluid communication with said conduit means.

5. A flushing system as claimed in claim 1 wherein each flushing channel has a width or transverse dimension of 150-500 mm.

6. A flushing system as claimed in claim 5 wherein each flushing channel has a width or transverse dimension of 300-400 mm.

7. A flushing system as claimed in claim 1 wherein said suspended floor is formed from -

(i) a plurality of modular structural blocks formed in abutting relationship which form a multiplicity of longitudinal rows with a spacing therebetween which corresponds to a respective flushing channel, and (ii) a plurality of slotted or perforated modular tiles laid transversely across a pair of spaced rows of structural blocks in abutting relationship.

8. A flushing system as claimed in claim 1 wherein said conduit means includes a manifold conduit having a plurality of flow control valves located at spaced intervals along the length of manifold conduit with each flow control valve located adjacent an inlet of a respective flushing channel.

9. A flushing system as claimed in claim 8 wherein the flow control valves are manually operable.

10. A flushing system as claimed in claim 9 wherein the flow control valves are selected from gate valves, ball valves or butterfly valves.

11. A flushing system as claimed in claim 2 wherein the receiving tank is located underground below a bottom level of each flushing channel.

12. A flushing system as claimed in claim 3 wherein the pump is submerged by water in the receiving tank.

13. A flushing system as claimed in claim 4 wherein there is provided float controlled valve means for controlling flow of water through said return conduit.

14. A flushing system as claimed in claim 1 wherein each flushing channel is oriented in a direction longitudinally of the livestock shed or barn.

15. A flushing system as claimed in claim 4 wherein the treatment location is located above the level of the header tank and water flow from the treatment location to said header tank through said return conduit under the influence of gravity.

16. A flushing system as claimed in claim 1 wherein each flushing channel extends beyond an associated end of the livestock shed or barn.

17. A method of flushing faeces, urine, animal feed and other animal detritus from a floor of a livestock shed or barn which includes the steps of -

(i) passing water on a controlled basis through a plurality of flushing channels located on said floor in the form of a full width stream of water and at a velocity sufficient to maintain said animal detritus as a suspension to thereby flush said animal detritus from each flushing channel; and

(ii) collecting water entrained with said animal detritus after passage through each flushing channel for ultimate disposal.

18. A method as claimed in claim 17 further including step (iii) wherein the water collected in step (ii) is passed to a receiving tank and in a further step (iv) is transferred under pressure from said receiving tank to a treatment location.

19. A method as claimed in claim 17 further including a step (v) wherein treated water is recycled from the treatment location to a header tank which is in fluid communication with conduit means associated with said flushing channels.