CA2045633A1

CA2045633A1 - Process and installation for manufacturing a pasteurized substrate

Info

Publication number: CA2045633A1
Application number: CA002045633A
Authority: CA
Inventors: Adelrich Spescha
Original assignee: Adelrich Spescha; Adymat Ag
Current assignee: Adymat AG
Priority date: 1989-11-22
Filing date: 1990-11-21
Publication date: 1991-05-23
Also published as: WO1991007365A1; EP0429744A3; EP0429744A2; JPH04505001A; AU6711590A; AU653503B2; HUT60985A; CH679999A5; CZ580290A3

Abstract

ABSTRACT
In a process for manufacturing a pasteurized substrate by biological decomposition of organic refuse, the refuse is introduced into a container whereit is intimately mixed with air under constant stirring during a residence time in order to induce bacterial aerobic decomposition, and the end product is refined.The process of the invention is characterized by the following processing steps: a) The container (1) is half filled with a mixture of solid refuse to be decomposed.
Liquid substances are then added, and at the same time air is supplied naturally by constant stirring of the mixed refuse. Stirring is continued for a first residence time of 2 to 3 hours. b) A quantity not greater than one-third of the weight of the mixed refuse of decanted clarified sludge at a temperature equal to that of the mixed refuse is added. A quantity of white lime equal to approximately 4% of the weight of the clarified sludge, depending on the acid content of the mixed refuse, is added. Stirring is continued for a further residence time of 69 to 70 hours. An installation for carrying out the process, with a container for the refuse to bedecomposed, including feed and discharge devices and screw conveyors for stirring the mixed refuse, comprises a parallelepipedal container (1) with a heptagonal profile in the shape of an inverted house roof with its ridge pole sunk in the ground and whose width (b) is greater than its length (I). The base of the container consists of two identical, obtuse-angled, mutually inclined half-bases (1.1, 1.2) the surface of which is shaped to match the screw conveyors (2). At least one screw conveyor (2) is arranged in the vicinity of the two sloping half-bases (1.1, 1.2) parallel to the latter.

Description

1~ JUL '~ Z4 INTERTEXT GRIS 0~ 1 71 ~33 144 P. Z
~045~3.3 Process and In6t~11ation for ~qan~fucturln~ P~leur~zod Sub~tratto The invention relates to a procoss for manufacturiny pa~teurized sub~ates according to the n ain clairn a~ Patent Claim 1.
In a known pr~cess of appropriate ~encric form, ~ollowin~ prcparation in the usual manner by p~cosses of siftin~. sopAration and size roduction, rofusc is introduced into a circl~lar fermentation container with a circular motion of distribution at the porimeter and, for the purposo of introtucing and malntaining ~n aorobic and biological process of dccompo~ition, the rcfuse is constantly agitated and gradu~lly displaced towatd~ 2he central exit aperturo of the fcrmen~tion container. ~he refuse is agitated by a sequenc¢ of connected movcment~ running in a sctew-like motion in a predetermined circular direction. This process provcnts the s~called "shott circuit currents" in the refuse material.
wherc par~ o~ the refuse to be troated roacb the exit aper~ure in a shorter time than the residcnce time required for coJnpletc biolo~ical decomposition or conversion rospoctively of the rcfuse mstori~l. 'rhus ~n anempt is made to a~oid mixin~ the a~ Y ferm~int~ finfll nr~u~t n~th J .. .~ v~ ", ~v~pV~;U.
From thi~ ~u~gestion concerlline the proce~s in que~tion, no oxact details can be gathcrod about thc to~l len~th of time neoded for the process. On the bas~ of appEopriate refetence to th~ corre~pondin~ publication. it i9 highly probable that thc rosidence time of the waste to be treated in the fermontation container will bc, perhaps, bctween 4 and 6 d~ly9. Further.
this su~egostion does not state whether there i~ a periodic proccss proccdurc in which a definite ammlnt o~ refu~e i~ put into thc fermon~ation ~ntainer cach time arld then fermcnted or whot~let it i8 El matter of a continuou~ly supplied and runtun~ decomposition p~S8.
Flnally, the su~gestlon does not offer any advice as to the oomposition of tho re~u8e to be proces~cd: whether and t~ what extent agrieultural waste, sowage sludge, liquid man~n etc can bc processed usin~ this method, Only urban reflJse is montioned as a raw m~terial to bo treatet.
Furthormoro, ~e question of stonlizin~ the flnal product retnains opon.
rn accordance with tho shtcmollt, the proces~ in question is simply an int~nsivo aera~on of tho rofuso materia~ by continuous agitation ~ same, while it is trar~ported from ~e inlet of the fcnnentation container to the outlet of ~ne in an unspcci~led residence time.

19 JUL ~91 21: 25 INTERTEXT GflIS ~IE141 71 333 144 P. 3 The object of the present in-~ention is the provision of a process as doscnbed which ~llows tho biological convorsion of or~anio refuse material into a past~urized ~ubstrate within tho shortest possible rGaidencc time, whilo avoidin~ the previously mentionod disadvantages of the knowtl fcrmenting m~thods.
According to the in~ention, the stated object i9 achioved by thc treatmcnt proccss a~ tescnbed in the steps given in Patent Cla~m 1.
Mea~uros fo~ a particularly advantageous ~nd expanded form of thc process a~cording to the invention can be taken from the attachod Patent Claims ~ to 10.
A procedure of this type facilitates a spcedy, rnechanized and controllable decomposition of all kinds ~f or~anic refuse material, including ~ewa~c sludge, ~nimal carcasses, liquid manure, etc, with degennination, into a p~teudzcd substrate without the use of e~traneous heat.
Further the invention ha~ a facility for implementlng the process according to the prc~ent invention with ~ receptaclc for the refuse mi~ture oo bc treatet, to~ether with devicos for supplying the refuse and for removin~ the already fermented product, as well a~ having scrow convey~r~ for stirrin~ the refuse mixture.
There is a ~nown composting device to carry out the above mentioAed, anticipated process. This has a ~wivel brid8e which tra~rsrses the as~ocia~d circul~r forment~tion containor along tho di~neter of same and which can movc alon~ thc rails secured in cireular fathion around the u~er ~edu of the conta~ fltJB~halt~ &
clectric driYe via a step-down ge~r acting on one of the rollers In this way it i~ also ~upported by a central be~rin~ which is attached to the truncatcd cone shaped innor wall in the centre of the in~ide of the fermen~ti~n conlainer. Fur~er the swivd bridge corlsists of two b~idge halves which eac.h ~o from the central bea~n~ radially to the perimebr of the cont~iner. ~ne of the brid8e halves be~rs a scrcw conveyor which is assi~ned to convey thc waste material so bc processcd to the penphery of tbo fermentation cont~ineJ. This reachc~ from a receiving funnel assigned to tho eentral bearing to a delivery chute situated in the poriphcral area. On tho other half of thc bridge, numerous motor-driven acrating screws a~o attached in two parallcl row~, which run ~dially bet~vcen the truncatod conc shaped inner wall and the cylindrical outer wall of the fermontation containcr. The po~nts of the aeratin~ serews are sct in a downwards diroction from tlK bridge and arc inclined diagonally so that each spir~l tip poinh forwards in thc direction ~f rotation 0I the bridge and at the same time in tho direction of the outer wa~i of tho i ., `~ ,. -` :

19 JUL '91 2~:SS I~TERrEXT GFIIS 0E141 71 933 144 P.3 20g5f.i;33 container~ tn ~dition, the aerating screws in one row are displaeed in a r~i~l Jir~Jti~l~.witt. r~a~ IJ~ eUI~ T~ no~oul ou~fQoo of the aerating scrovs lifts tho rofusc material fsom the base of the oontainer and, stinin~E continuously, transports it upwards.
The fennentation container can be ~IIIod to ~enveen 80 and 859~a of thehei~ht of the wall.
The rotation of the brid~o is supported b~r the aerating screws which rotate in the s~me direction ~nd intimatoly mi~ the refuse actoss the wholc wid~ of ~he fermentati~n containen l`he air neeessary for the sa~d process is ~uppliet by me~n~ of a ventilator, via a number of openin~s ncar thc b~e in the outer wall and vi~ the distnbutivn pipes connecting tho openings with tho ventilator.
The tr~ated refilse matenal ~1n he. ~xpPetnli ~n rli~ itc~,lf in a continual ~nd un-form movemont from the outcr wall to the exit in the inner wa}l as a result of the diagonal position of the acrating screws~
Tho penpheral speed of ~e individual sorating screws can be set to achievo a suitablc decompo~ition of the refuse mateNal. There are al30 mea~uros to suspond the opcration of the device in casc an aerating screw comes into contact with an unexpected obstacle.
A numbcr of p~wer operated probes, which can be inserted into the fermentation conta;ner from below, help to achicve the prevailing oonditiona of, for ~xnmpl~, temperntllr~ nntl nYy~n rnnt~nt nF ~hr r~fil~r being treated and to control thc supply of sir.
A rna.jor disadvQntage o~ the equipment s~ doscribed previously is its cost of construction~ There is al~o the drawback of the considerable arnount of ener~y requircd and the numerous opportunities for error~
~ further objcct of the invention i9 thcrefore to creat~ a pieee of egluipment in accordance with the $cneric type in particul~r to carry out thc process outlined abovo. This is to facilitatc tho productio~ of a pssteunized substratc which is satisf~ctory in both technological and economic terms while ~Yoiding the aforc-mentioned disadvanta~es~
Accordin~ to the inYc~tion, thc stated objoct is ~chicvod by ~ device with in~tructions accordiny to the characteristics given in the separate Pa~ent Claums 11.
Charactoristic~ o~ a particul~rly useful devclopment to the device are given in the attached Patent Claims 1~ to 21.

1~ JU~ '~31 Zl:?6 INTERTEXT G~IS 2041 71 ~C~3 144 P.5 ~045633 Accordin,~ to dle invention, tbis de~ico is 3igniffcantly simpler than the ~l~,vi~ kn-~n ;n the ~rt. An incr~-d op~ tiom~l roli~bilit~ und m~ cd reduction in cnerS~ usap can thereforo bo anticipnted.
The invention i9 explained in greator dotail in the drawing, ~or ~xamplo with a proferred way of constructing the device for substr~te pasteurizstion .
Shown u~:
Figure 1 a device for producing ~terilized substrates according to the invention In pro~lle along onc of thc cuttin~ plane~
1-1 mentioncd in Pigu~e 2 and Fl~ure 2 horizontal project;on on tho devicc according to Fi~ure 1, whcrein the upper pau~ has been removed atong a ~iven plane sectio~
The device includes a teceptacle 1 for th¢ rofuse to bc decompo~ed, two pairs ~ ~crc~ conveyon 2 fixed in thc receptacle to stir aud, at the sarn~
timc, aerato the rcfuse rnixture and two delivcry spirals 5 assigned tc) each of the wrew conveyors.
From above, the recep~cle is a quadrilateral shape but when viewed from the fiont, it has a penta~ona3 shapo resembling ~n inverted house whose rc~ sunlc into d~e ground. ~# can be seen particularly from ~Igurc 2, the receptaclo h~r. a largc width ~ in compari~on with its length I. The b~sc of tho container consists of t~40 equal, obtuse-angled, mutually inclinet b~lse hal~os 1.1, 1.2 whose surfaceo. are shaped to rnatch the ~nw ~ nv~.ynrq 7 ~n~ ~ ThP fmlr o~ r ~om~-oso Qr ~mmB~d tlO thClt one pair is ne~r one of the two slopin~ half-bases 1.1, 1.2 of the reccptaclo 1, runDing par~llel to same. Thc an~le of inclination of the hal~ ses 1.1, 1.2 to tho hoAzontal is advantageously chosen t~ be 30 degrees. A 4uadrilfltoral con~iner lid ss dcs~gnet to cover the recep~cle 1 and ~akes the form of t~vo idcntical lid halve~ 1.3, I.4. Both lid hal~es 1.3, 1.4 aro made of l~vel, rsctangutar lit elemen~ 1.3.1, ~.4 I which are linkcd togetbor by hinges. ~n th;~ way, when tho container iid i8 un, both ~f the inna nei~hbourin,~ lid elemen~. 1.3.1, 1.4.1 can bo folded b~c~ to create ~n opening l.S in the lid for the refusc mixture A which ;B to be decomposed. The supply of refuse m~xture ~ or the components ~f s~ne to the opening 1.S can take placc in way9 known in the art, for example by me~ns of a c~>nveyor belt.
rt i~ advan~eous to include at least one door 1.6.1, 1.7.1 in the pcnta~ond wQll~. (ie, in thc front wall 1.6 and in tbe ~ear wall 1.7) to facili~te servicing ~nd cloaning work ir~ide ~e receptaclo 1.

i~ JUL '91 Z1:27 INTERTEXT GRIS E~041 71 ~33 144 P.6 Z04s633 Thc bcaring 2.1 of the s~row conYeyors 2 on each of tho assi~nsd half-bases 1. I, 1.2 of the rocoptaole is po~itioned at both cnds of the scrow. A
reves~lng electric drive 3, connected to the upper ~crew end, is arr~n~cd on thc narrow side 1.8 or 1.9 of thc out~idc ~uRuc:e of thc receptacle 1, throu~h which the relevant 6crew end is c~Tie~.
A lenth o~ 4.5 metres pro~cd to be a particularly ~uitable lon~th for the scrcw conveyors 2. A diarneter of 60 to 80 mm is ~uitable for the sh~ft-shaped sctew core 2.2. The sc~ow convcyors 2 aro approp~atoly shsped to improve the mi~ture of treated refuse wlth the freely circulating air, ie they are slulpcd in ~ucb a way that the conveyin~ direction of the first 859~o of the ovcrall length goes from thc bottom of thc screw to the top, and in the rcver~c direction on th~ rem~inin~ 1S% of ~he len~th.
Bctween the lower ends of bo~h pairs of 6crcw conveyors 2 in ~e co~ner formed by the two ir,lclined half-bases 1.1, 1.2 of the receptac~e 1 thex is a partition 4 witb a triangular profilc. The height OI the parti~on should be le~s than tho diamcter ~f the ~crcw projcctcd onto iL In acidition, there are ~ number of cntrance ports 4.1 ;n the partidon 4, via which the air requlred~or n,c bac~ l ~n)b~ ;UIIVt;~i~l~ ur~ 7rU~ u~
the receptacle I by the vacuum prosent inside the the receptacie.
The extraction of the fermented substrate OCCU11'9 at the mecting point of the two sections of cach ~crew eonveyor, advancing in opposite directions and having a mutual aspect ratio of 8~%:1S9'o of the ~crew length. Hore thcrc is a dclivery screw S on each of the two inclined half-bases 1.1, 1.2 of thc ~eceptacle 1, symmctrically posiffoned between the two screw conveyors 2 ~si~ned ~ere. The upper end ~f each dclivery sorew S penetra~os tho rcspccdvc narrow sides 1.8 or 1.9 of tho receptacle I and i8 linkod to an clectric drive 6. Corrcsp~ndin~ to the windin~
dire¢tion of the deli~er~r #crew 5 ~om the lower end of the screw upwards, an outlet 7 i~ positioncd near ~he uppcr end of each one, facilitatin~ the movement of the final pr~duct, for o~ample by means of a conveyor bolt. The leng~ of the delivory screw 5 extends from the outlet 7 to the hoight at which thc opposin~ actions of the screw conveyors 2 mcct.
control unit re~ulates the downwards stirring motion of the serew con~rcyors 2 with a number of revolutions n equal to 6 ~o 8 revolutions/minute with an initial cycle timc tl cqual eo 10 n~inutes for tho forward displacement of the re~use mixture, with a secondary cloek e ~ ~u~l ~ 0.5 lI~ U~ IIC ~ CCl~CHt ~f ~hc mil~turo ~d with a penod l~ equal to S minute~ for the standst~ll between the two motions. Th~ ¢ontrol unit is not depicted in the dra~ving. The rcarward motion of thc screw conveyor i5 nece5~a~y to prevent the material from ~ticking to the inner surf~ces of the rccept~cle 1. This avoids ths creation 19 JUL '91 Z1 2e INTERTEXT ~;~IS 00~11 71 933 14~ P.7 ;~:045633 of "dead" %on~s and the wholc of the refuse mixture is continuously ~itated shroughout the compostin~ process.
The in~ention facilitates the elimination of all kints of refuse, such as urban or agricultural waste, sewage ~ludge, liquid manure. animal catca~ses ctc and malces it possible to use it in the form of pastcurizcd substratc with tho aid of a controllable and biological rotting procoss which can be mech~nically implementet wi~ a tOt~ll duration of 72 hours, whetein the temperature of OVOt 80 dogreos Celsius that occllrs during ll-C t~ U~U~;l wil~ uL t;~r~ ~Ui~
The so~alled carcass soup which is addod to thc re~use mixture is a meat ~oup made ftom anin al carcass with the fat content removcd. This is ncccssaly because ~e fat bloclis thc capillaty routes in thc rcfuse mixture and thereby rostricts the supply of air for the totting process.
the rottin~ p~cess has a tendency to come to a standstill, domons~rated by a ~apit coolin~ of the treated refuse mixture as a result of thc prcscnce of acidic refuse rnaterial, ~us lowering the ph value, the proeess can be re-activaled by the addition of small quantities of whitc lime or by mixing an additional quantity o~ wood cbip~ qnd~or untreated grass and/or straw manure into the refuse m~xture.

Claims

PATENT CLAIMS

1. Process for manufacturing pasteurized substrates by aerobic biological decomposition of organic waste, wherein such waste is introduced into a container, where it is continuously stirred in order to mix it intimately with air during a residence time, thus inducing bacterial aerobic decomposition, and the end product of this decomposition process then undergoes a refining process characterised by the following stages, whereby:
a) After half-filling the container with a mixture of various kinds of intermixed refuse of a solid consistency and then adding liquid substances while at the same time continuously for an initial residence a natural air supply, stirring is continued for an initial residence time of two to three hours, b) Then doses of decanted clear sludge are added, the maximum weight of which must not exceed a third of the weight of the solid waste mixture and the temperature of which must be equal to that of the partially fermented waste mixture, a quantity of white lime is also added depending on the ph-value of the waste mixture, in the proportion of 4% of the weight of the clear sludge, and stirring is continued for a further residence time of 69 to 70 hours.

2. Process as described in patent claim 1, whereby the mixture ratio of the waste to be decomposed, mixed up together, consists of a proportion of 30 to 40% of dry substance and a proportion of 60 to 70% of moist substance.

3. Process as described in patent claim 2, whereby the dry substance consists of biologically degradable organic household and/or agricultural waste matter, whereas the moist substance consists of liquid manure and/or so-called carcass soup with fat content removed.

4. Process as described in patent claim 3, whereby crushed material such as wood chips and/or leaves are added in order to increase the inner friction surfaces of the waste mixture.

5. Process as described in patent claim 4, whereby there is a timing program for the control of the stirring process so that the material advances in one direction for a certain length of time and then in the reverse direction for a certain length of time, thus intensively combining the waste mixture to be processed at different rates (d Index 1, d Index 2) both with regard to the directions of feed and with a standstill interval (d Index ?) in between.

6. Process as described in patent claim 5, whereby the timing program allows an initial conveying cycle time (t1) of 10 minutes for advancing the waste mixture away from the feed side of the container and a second conveying cycle time (t2) of half a minute for advancing the waste mixture in the opposite direction, and a time interval (t?) of five minutes for the standstill time between the two conveyor movements, and whereby the advance of the waste mixture occurs simultaneously with a stirring motion of six to eight rpm inducing static natural aeration.

7. Process as described in patent claim 6, whereby before adding the clarified sludge, the same is warmed to the processing temperature of 20 to 30 degrees centigrade reached in the waste mixture at the end of the first phase of treatment.

8. Process as described in patent claim 7, whereby instead of or in addition to wood chips, untreated grass and/or straw manure is added to the waste mixture.

9. Process as described in patent claim 7 or 8, whereby the fermented end-product is ground to a fine grained pasteurized substrate in a grinding operation.

10. Process as described in patent claim 9, whereby the product resulting from the decomposition process undergoes a two-hour drying process.

11. Plant for implementing the process as described in patent claims 1 to 10, with a container for depositing the refuse to be composted, including devices for introducing the same and for delivering the fermented end-product as well as screw conveyors to stir the waste mixture, whereby there is a parallelipedal container (1) with a pentagonal profile in the shape of an inverted house with its roof sunk into the ground, having a larger width (b) in comparison with its overall length (l), wherein the base of the container consists of two equal, obtuse-angled mutually inclined base halves (1.2, 1.2) whose surfaces are shaped to match the screw conveyors (2) and wherein at least one of the screw conveyors (2) is assigned to the proximity of one of the two inclined base halves (1.1, 1.2) and runs parallel to the same.

12. Installation as described in patent claim 11, whereby the angle of inclination of each of the two base halves (1.1, 1.2) of the receptacle (1) in 30 degrees from the horizontal.

13. Installation as described in patent claim 12, whereby there is a quadrilateral container lid consisting of two lid halves (1.3, 1.4), wherein the lid halves (1.3, 1.4) are made of rectangular lid elements (1.3.1, 1.4.1) hinged together, and when the lid is on the container the two inner neighbouring lid elements (1.3.1, 1.4.1) can be folded back to create an opening (1.5) in the lid for the refuse mixture (A) which is to be decomposed, as well as at least one door in each of the two pentagon-shaped walls of the container (1), is the front and rear wall (1.6 and 1.7), for servicing and cleaning purposes.

14. Installation as described in patent claim 13, whereby a pair of screw conveyors (2) running parallel to each other are installed near each of the two inclined halves (1.1, 1.2) of the base of the receptacle (1), running parallel to the same.

15. Installation as described in patent claim 13 or 14, whereby the bearing (2.1) of each screw conveyor (2) assigned to the base half (1.1, 1.2) of the receptacle (1) is situated at the end of each of the two screw ends, and whereby a reversible electric drive (3), connected to the top end of the appropriate screw conveyor (2), is assigned to the outer surface of one of the narrow sides (1.8, 1.9) of the receptacle (1).

16. Installation as described in patent claim 15, whereby the screw conveyors (2) with an overall length of 4.5 m have a core diameter of 60 to 80 mm, and whereby the screw core (2.2) is a hallow shaft.

17. Installation as described in patent claim 18, whereby the screw conveyors (2) are constructed in such a way that the conveying direction on 85% of the overall length goes from the bottom end towards the top end of the screw and in the opposite direction on the remainder of the overall length.

18. Installation as described in patent claim 17, whereby two delivery screws (8) for the removal of the fermented substrate are situated symmetically between the two screw conveyors (2) assigned to each of the two inclined base halves (1.1, 1.2) of the receptacle (1), the overall length of which extends from an outlet (7) in the upper range of the same to the level of the joint between the two sections of the two neighbouring screw conveyors (2) running in opposite directions to each other, and bearing a relation to each other of 86% to 18% of their overall length.

19. Installation as described in patent claim 18, whereby the upper end of each of the two delivery screws (8) goes through the relevant narrow side (1.8, 1.9) of the receptacle (1) and is connected to an electric drive (6) attached to the outer surface of the receptacle, and whereby the conveying direction of the two delivery screws (8) runs from the top end of the screw towards the bottom.

20. Installation as described in patent claim 19, whereby there is a partition wall (4) with a triangular profile situated between the bottom end of the two pair of screw conveyors (2) in the corner formed by the two inclined half-bases (1.1, 1.2) of the receptacle (1), the height of the said partition wall being less than the diameter of the screw projected onto it.

21. Installation as described in patent claim 20, whereby there is at least one air inlet opening (4.1) in the area of the partition wall (4).