WO2012002813A1 - Biogas system - Google Patents

Biogas system Download PDF

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Publication number
WO2012002813A1
WO2012002813A1 PCT/NL2011/050472 NL2011050472W WO2012002813A1 WO 2012002813 A1 WO2012002813 A1 WO 2012002813A1 NL 2011050472 W NL2011050472 W NL 2011050472W WO 2012002813 A1 WO2012002813 A1 WO 2012002813A1
Authority
WO
WIPO (PCT)
Prior art keywords
biogas system
flanges
segments
tank
biogas
Prior art date
Application number
PCT/NL2011/050472
Other languages
French (fr)
Inventor
Samuel Castro
Mirik Castro
Original Assignee
Simgas B.V.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Simgas B.V. filed Critical Simgas B.V.
Priority to AP2013006688A priority Critical patent/AP3498A/en
Priority to CN201180032803.XA priority patent/CN103003410B/en
Publication of WO2012002813A1 publication Critical patent/WO2012002813A1/en

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M21/00—Bioreactors or fermenters specially adapted for specific uses
    • C12M21/04—Bioreactors or fermenters specially adapted for specific uses for producing gas, e.g. biogas
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M23/00—Constructional details, e.g. recesses, hinges
    • C12M23/02—Form or structure of the vessel
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M23/00—Constructional details, e.g. recesses, hinges
    • C12M23/34—Internal compartments or partitions
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E50/00—Technologies for the production of fuel of non-fossil origin
    • Y02E50/30—Fuel from waste, e.g. synthetic alcohol or diesel

Definitions

  • Biogas systems comprise a digestion chamber to contain a mixture of manure and other biodegradables, called feedstock, that is partly dissolved in water in order to produce methane gas.
  • feedstock a mixture of manure and other biodegradables
  • the methane gas can be used for household or small industrial purposes.
  • a known biogas system is build of bricks. As a closed dome of bricks is necessary to enclose the methane gas, a skilled mason has to be present at the building site and even a skilled mason has some weeks work to build one biogas system, and before building heavy bricks need to be supplied to the building site. A brick biogas system needs to be engineered for every size and every location separately. Once it is in place it size is fixed.
  • the invention provides a biogas system comprising an elongated tank forming an elongated internal digester chamber, wherein in its longitudinal direction the tank comprises in series a front end section, multiple intermediate sections and a back section that bound the digestion chamber, wherein the front end section, the intermediate sections and the back section comprises flanges that are coupled against each other.
  • the biogas system according to the invention can be supplied as separated sections which are subsequently assembled by coupling the flanges against each other. This can be done by low skilled people.
  • the intermediate sections comprise multiple intermediate segments which are positioned in series around the longitudinal axis of the tank, wherein at the meeting ends the intermediate segments comprise flanges that are coupled against each other.
  • the intermediate sections can be formed by coupling the flanges thereof against each other on site.
  • the intermediate segments can be transported to the assembly site in a compact manner.
  • the tank can be scaled up in its length by supplying the necessary amount of intermediate sections.
  • the intermediate segments comprise a deformable seal strip that is formed as one unity with the flange, wherein the deformable strip extends oblique from the flange with its distal end towards the digestion chamber.
  • the deformable seal strip is oriented from the flange towards the digestion chamber and abut with its distal end the opposite flange to be coupled with.
  • the feed stock in the digestion chamber can penetrate between the coupled flanges up to the seal strip, whereby it accumulates and further closes possible gaps between the coupled flanges.
  • the biogas system comprises an expansion chamber above the top tank half that is separated from the digestion chamber and that is in fluid connection with the digestion chamber via an outlet channel only.
  • the expansion chamber can store a fraction of the mixture that is expelled from the digestion chamber via the outlet channel due to the production of methane gas. The mass of the expelled fraction can keep the produced methane gas under some pressure.
  • the expansion chamber is open at the upper side, whereby the level of produced methane gas can be easily derived by notifying the level of the mixture in the expansion chamber by sight.
  • the expansion chamber is bounded by a circumferential wall that extends upright from the tank.
  • the circumferential wall can be provided together with the tank to be assembled thereon.
  • the circumferential wall comprises a free extending upper edge that bounds the open upper side of the expansion chamber.
  • the circumferential wall comprises wall segments that are coupled against each other, wherein the transitions between the wall segments preferably coincide with the transitions between the intermediate sections.
  • the wall segments can be easily scaled up together with the intermediate sections.
  • the tank comprises an upper wall that bounds the upper side of the digestion chamber and the lower side of the expansion chamber, wherein the outlet channel extends downwards from the upper wall into the digestion chamber.
  • the lower side of the outlet channel thereby determines the maximum height of the methane gas body in the digester chamber. In this manner it is prevented that too much mixture is expelled towards the expansion chamber, and it is thereby also prevented that the gas pressure of the methane gas exceeds values beyond the specifications of the gas appliances that retrieve the methane gas from the digestion chamber.
  • the flanges at the meeting ends of the intermediate sections extend in vertical direction all below the lowest end of the outlet channel, whereby the coupled flanges are continuously submerged into the feedstock. Thereby the abovementioned sealing action of the feedstock between the flanges is assured.
  • the tank comprises an upper wall that bounds the upper side of the digestion chamber, and an inlet channel that extends downwards from the upper wall into the digestion chamber, wherein the inlet channel is spaced apart from the outlet channel in the longitudinal direction of the tank.
  • the inlet chamber allows the methane gas to be enclosed inside the digestion chamber while more feedstock can still be inserted in the digestion chamber.
  • the outlet channel is separated from the expansion chamber, wherein the outlet channel is preferably upwardly extended by a circumferential wall that is located inside the expansion chamber.
  • the inlet channel extends in downward direction deeper inside the digestion chamber than the outlet channel, whereby superfluous methane gas will escape via the outlet channel only, thus keeping the inlet area free of methane gas.
  • the intermediate tank sections form a cylindrical circumferential wall of the tank.
  • the tank comprises a top tank half and a bottom tank half having horizontally extending flanges that are coupled against each other, wherein the top tank half comprises in series a front top segment, multiple intermediate top segments and a back top segment having vertically extending flanges that are coupled against each other, wherein the bottom tank half comprises in series a front bottom segment, multiple intermediate bottom segments and a back bottom segment having vertically extending flanges that are coupled against each other.
  • intermediate top segments and the intermediate bottom segments are identically formed, whereby these segment can be produced in an efficient manner.
  • the sections comprise a continuous insertion chamber along the flanges, wherein the insertion chambers of the coupled flanges are positioned straight opposite each other, wherein a common resilient sealing is inserted in the opposite insertion chambers.
  • the inserted and enclosed resilient sealing seals the coupled flanges along the length, whereby the mixture and the produced methane gas remains enclosed inside the digestion chamber, at least to a large extent.
  • the sections comprise a wall section between the flanges, and an U-shaped insertion profile for the sealing between the wall section and its flange, wherein the wall section connects to the back of the U-shaped insertion profile and the flange forms a continuation of one of the legs of the U-shaped insertion profile.
  • the U-shaped insertion profile forms a clearly visual indication for the intended position of the seal, whereby can be ensured that the seal will be placed in the intended way.
  • the resilient sealing comprises an elongated base strip having sealing flaps along the length of the base strip that extend sideways from the base strip.
  • the base strip and the sealing flaps are in cross section configured as arrow heads that point outside.
  • the arrow heads indicate the intended insertion direction of the seal.
  • the flanges are coupled by multiple couplings that are evenly distributed along the flanges, wherein the couplings comprise a coupling pin having a coupling head and a coupling shaft extending from the coupling head, wherein the flanges comprise sets of aligned holes wherein the coupling shaft is inserted.
  • the couplings comprise a wedge having two wedge legs to accommodate the coupling shaft in between, wherein the wedge legs and the coupling shaft comprise a series of locking edges that incline with respect to the longitudinal axis of the shaft.
  • the coupling can be tightened by bringing the coupling shaft further between the wedge legs by pushing the wedge towards the shaft.
  • the inclined series of locking edges that are brought against each other provide the conversion of the sliding movement of the wedge transverse to the longitudinal direction of the coupling shaft into a tightening movement of the coupling head towards the wedge in the longitudinal direction of the coupling shaft.
  • the locking edges are barbed shaped to enable the accommodation of the shaft between the wedge legs and to counteract disengagement. In this manner the couplings can be installed once by one way locking interaction between the locking shaft and the wedge.
  • the flanges that are coupled against each other can be biased towards each other when the coupling head has a convex shape and is configured to be biased towards a flatter shape when the wedge is tightened.
  • sections or segments or couplings are made of plastic, preferably HDPE .
  • Figure 1 is an isometric view of a modular biogas tank according to the invention
  • Figure 2 is an isometric view of the biogas tank according to figure 1, wherein the upper parts have been removed;
  • Figure 3 is an isometric view of the biogas tank according to figure 2, wherein some side parts have been removed;
  • Figure 4 and 5 are side views of the biogas tank according to figure 1, for different illustrating purposes;
  • Figure 6 is a back view of the biogas tank according to figure 1;
  • Figures 7A and 7B are a cross section and an isometric view of a first coupling of the biogas tank at the position as indicated in figure 2;
  • Figure 8 is a cross section of a second coupling for the biogas tank at the position as indicated in figure 2;
  • Figure 9A is a cross section of two wall segments and a seal at the position as indicated in figure 3;
  • Figure 9B is an isometric view of the seal according to figure 9A;
  • Figure 10 is a cross section of the wall of the biogas tank at the position as indicated in figure 2
  • Figure 11A is an isometric view of a second modular biogas tank according to the invention.
  • Figure 11B is an exploded view of the modular biogas tank according to figure 11A;
  • Figure 12 is a longitudinal section of the biogas tank according to figure 11A, for different illustrating purposes ;
  • Figure 13 is a cross section of the modular biogas tank according to the line XII-XII in figure 11A;
  • Figure 14A is a detail view of the modular biogas tank according to circle XIII in figure 13;
  • Figure 14B is an exploded view of the modular biogas tank according to figure 14A;
  • Figure 15A is an isometric view of a third coupling for the biogas tank
  • Figure 15B is an exploded view of the coupling according to figure 15A;
  • Figure 16 is a detail view of the modular biogas tank according to circle XV in figure 11A;
  • Figure 17 is a cross section of the modular biogas tank according to the line XVI-XVI in figure 16;
  • Figure 18 is an isometric view of a fourth coupling for use in the modular biogas tank of figure 1 or the alternative biogas tank of figure 11A.
  • FIGS 1, 4 and 6 show a first modular biogas tank 1 according to the invention.
  • the elongated biogas tank 1 is destined to digest a mixture of manure and biodegradables, called feedstock, that is partly dissolved in water in order to produce methane gas under low pressure.
  • the biogas tank 1 comprises a front bottom segment 20, three intermediate bottom segments 40, 41, 42 and a back bottom segment 30, a front top segment 50, three intermediate top sections 70, 71, 72 and a back top segment 60 that are coupled along their sides to bound a closed digestion chamber 2.
  • the biogas tank 1 further comprises two vertical side walls 80, 82, a vertical front wall 81, and a vertical back wall 83 on the top segments 50, 70, 71, 72, 60 to bound an open expansion chamber 3 having on top an overflow 84 above the digestion chamber 2.
  • the back top segment 60 is provided with an inlet channel 5 that has been extended by a vertical shaft 90 aside the expansion chamber 3.
  • the front top segment 50 is provided with an outlet channel 4 that communicates between the digestion chamber 2 and the expansion chamber 3.
  • the segments are discussed in more detail hereafter, wherein reference is made to a horizontal plane of symmetry U, a longitudinal vertical plane of symmetry V and a lateral vertical plane of symmetry W of the outside shape of the biogas tank 1.
  • the front bottom segment 20, the back bottom segment 30, the front top segment 50 and the back top segment 60 have an identical outside shape, which is described hereafter under reference to the front top segment 50.
  • the front top segment 50 comprises a top wall section 59 extending parallel to the horizontal plane of symmetry U, an elongated straight front wall section 51 and two straight side wall sections 53 that together form a box- shaped stiffening construction, a second, substantially square straight front wall section 52 standing outwards from the middle of the elongated front wall section 52, two convex front wall sections 54 that extend between the square front wall section 52 and the elongated front wall section 51, and two convex side wall sections 55 below the straight side wall sections 53.
  • the front top segment 50 further comprises a first flange 56 that extends along the straight front wall section 51 and the convex wall sections 54, 55 in the horizontal plane of symmetry U, a second flange 57 that extends along the convex side walls 55 and the straight side walls 53 and a third flange 58 that extends along the straight top wall 59, both parallel to the lateral vertical plane of symmetry W.
  • the intermediate bottom segments 40, 41, 42 and the intermediate top segments 70, 71, 72 have an identical shape, which is described while referring to the second top segment 81 in figure 3.
  • the second top segment 81 comprises a straight, rectangular top wall 73 and two substantially square straight side walls 74 standing outwards from the top wall 73.
  • the second top segment 80 further comprises first flanges 75 that extend along the lower side of the side walls 74 in the horizontal plane of symmetry U, second flanges 76 that extend along the sides of the side walls 74 and third flanges 77 that extend along the sides of the top wall 73, both parallel to the lateral vertical plane of symmetry W.
  • the top segment 81 comprises upright insertion profiles 78 wherein the vertical side walls 80, 82 have been inserted.
  • Figure 9A shows in detail the second flange 57 of the front bottom segment 20 and the second flange 76 of the first intermediate bottom part 40, which are kept against each other by means of identical first couplings 100 of which one is shown in more detail in figure 7A.
  • the couplings 100 are equally distributed along all flanges to keep the flanges and thereby the segments tightly against each other over their entire length.
  • the front bottom segment 20 and the first intermediate bottom segment 40 are both provided with a U-shaped profile 11 that at the outer side of the biogas tank 1 connects the respective wall section 53, 74 to the respective flange 57, 76, and at the inner side of the biogas tank 1 is connected to an end flange 12.
  • the U-shaped profile 11 bounds an elongated, continuous insert chamber 10 along the flanges, wherein a resilient, elongated seal 14 has been inserted.
  • the seal 14 is shown in detail before its insertion in figure 9B.
  • the seal 14 comprises a flexible base strip 15 having for each insert chamber 10 an arrow-shaped side flap 16, a slim side flap 17 and a hollow side flap 18 on both sides of the base strip 15.
  • the base strip 15 and the side flaps 16, 17, 18 are (co) extruded from rubber, preferably Nitrile Butadiene Rubber (NBR) , and form arrow heads that point in the direction of the bottom of the insert chamber 10.
  • NBR Nitrile Butad
  • each of the segments is symmetrical with regard to the planes of symmetry U, W, V.
  • the first coupling 100 comprises a circular hole 101 in the second flange 57 of the front bottom segment 20 and an annular protrusion 102 on the second flange 76 of the first intermediate bottom segment 40 that is confined in the circular hole 101 like a male-female connection to bring and keep the flanges 57, 76 aligned against each other in a fool proof manner. Inside the protrusion 102 there is a smaller hole 103 which is provided with a locking edge 104.
  • the coupling 100 further comprises a plastic locking pin 110 which is shown in detail in figure 7B.
  • the locking pin 110 comprises an elongated shaft 112 and a broader, circular flat head 111.
  • the shaft 112 comprises a beveled front 113, two notches 114 on either side followed by an elongated hole 115 that divides the shaft 112 into two resilient halves 116 having multiple locking edges 117 at the outer side.
  • the locking edges 104, 117 are designed such that the locking pin 110 immediately locks permanently after having been inserted into the smaller hole 103 in direction F, which lock can only be tightened further by pulling or pushing further in direction F.
  • Figure 8 shows an alternative, second coupling
  • the coupling 200 comprises the same circular hole 101 in the second flange 57 of the front bottom segment 20 and the annular protrusion 102 on the second flange 76 of the first intermediate bottom segment 40 that is confined in the circular hole 101 like a male-female connection to bring and keep the flanges 57, 76 aligned against each other in a fool proof manner. Inside the protrusion 102 there is a smaller hole 203.
  • the coupling 200 further comprises a plastic locking pin 210 having an elongated shaft 212 and a broader, circular flat head 211.
  • the shaft 212 comprises a beveled front 213, two notches 214 on either side followed by an elongated hole 215 that divides the shaft 212 into two resilient halves 216 having multiple locking edges 217 at the outer side.
  • the second coupling further comprises a ring plate or cup spring 220 having a hole 218 which is provided with a locking edge 204.
  • the locking edges 204, 217 are designed such that the locking pin 210 immediately locks permanently after having been inserted into the smaller hole 103 in the direction F, which lock can only be tightened further by pulling or pushing further in direction F, such as by means of the pulling side of a hammer head 300 that is supported on the cup spring 217 to bias the cup spring 220.
  • the protrusions 102 and holes 103 are distributed such along the flanges that on the vertically extending flanges the holes 103 change into an protrusion 102 or reverse when passing the longitudinal vertical plane of symmetry V, and that for the horizontally extending flanges the holes 103 and protrusions 102 are opposite to each other when considered at the opposite sides of the longitudinal vertical plane of symmetry V.
  • the intermediate segments 40, 41, 42, 70, 71, 72 all still are identically shaped, enabling one and the same intermediate segment to be flipped over in direction A or turned around its vertical axis in direction B as indicated in figure 3 to be used at any intermediate position of the biogas tank 1.
  • the front bottom segment 20 and the back bottom segment 30 are still identically shaped to be interchangeable by turning around its vertical axis in direction C as indicated in figure 3.
  • the front top segment 50 uniquely further comprises a rectangular outlet shaft 65 extending downwardly from the top wall 59 to bound the outlet 4.
  • the outlet shaft 65 has a lower outlet edge 66 that extends parallel to and above the first flange 56.
  • the back top segment 60 uniquely comprises a rectangular inlet shaft 67 to bound the inlet 5.
  • the inlet shaft 67 has a lower inlet edge 68 that extends parallel to and above the first flange 56. In vertical direction, the lower outlet edge 68 extends below the lower inlet edge 66, over about 10 centimeter.
  • the inlet edge 68 has a smaller cross section than the outlet edge 66 to prevent that pieces of the feedstock are thrown into the digestion chamber 2 cannot be taken out at the outlet 4 anymore.
  • Both the front top segment 50 and the back top segment 60 are provided with upright insertion profiles 91, 95 wherein the vertical front wall 81 and the vertical back wall 83 have been inserted.
  • the segments 20, 30, 40, 41, 42, 50, 60, 70, 71, 72 have been manufactured by injection moulding of nitrogengas enclosing HDPE .
  • a cross section of a wall section is shown in figure 10.
  • the wall section encloses nitrogen bubbles in its centre and smaller nitrogen bubbles at both sides of the centre.
  • the solid outside faces of the wall section are free of bubbles.
  • the enclosed bubbles provide thermal insulation of the digester chamber 2.
  • the methane forming process inside the digester chamber 2 is explained under reference to figure 5.
  • the digester chamber 2 is fully filled by insertion of a mixture of water and feedstock via the inlet shaft 67, at a maximum level E some centimeters from the dome that is formed by the upper wall sections 59, 73.
  • the mixture starts to generate methane gas, which escapes from the mixture and stays enclosed in the digestion chamber 2 to push down the level of the mixture.
  • the lowest level D is determined by the height of the lower edge 66 of the outlet shaft 65, as the gas will escape via the outlet when the level has reached the lower edge 66.
  • the surplus of mixture is pushed into the expansion chamber 3 via the outlet 5.
  • the mass of the expelled mixture keeps the enclosed methane gas under pressure, which pressure is enough to force the methane gas into a hose 700 that is connected to the top side of the digester chamber 2.
  • the overflow 84 ensures that when the expansion chamber reaches its maximum level, the mixture is expelled in a controlled manner .
  • the mixture in the digester chamber 2 occupies 75% of the total volume of the digester chamber 2. That is, the total volume of the stored methane gas can be 25% of the total volume of the digester chamber 2.
  • the maximum volume of the expansion chamber 3 is 25% of the volume of the digester chamber 2 as well.
  • the entire biogas tank 1 can be scaled up or down only by adding or removing some identical intermediate segments 40, 70. In this manner the above mentioned volume rates will remain the same.
  • the vertical side walls 80, 82 are formed of interconnected side wall sections of which the interconnections coincide with the transitions between the top sections 50, 70, 71, 72, 60.
  • the intermediate segments, and the front segments and the back segments can be stacked and nested in themselves, allowing the biogas tank 1 to be transported as a compact package to its place where it will be assembled and employed.
  • FIGS 11A, 11B, 12 and 13 show a second modular biogas tank 301 according to the invention.
  • the biogas tank 301 is assembled out of segments, the form of which will be described hereafter.
  • the segments have been manufactured by injection molding HDPE, and have a substantially constant wall thickness over their entirety.
  • the segments enclose a straight circular cylindrical digester chamber 302 and an expansion chamber 303 with the same functionality as the ones described in relation to the first biogas tank 1 of figures 1, 4 and 6, utilizing the same methane forming process as described above.
  • FIG 11B shows in exploded view that the biogas tank 301 comprises a semicircular front bottom segment 320 and a semicircular front top segment 350 which together form a circular front end cap 351 for the digester chamber 302, and a semicircular back top segment 360 which together form a circular back end cap 361 for the digester chamber 302 as shown in figure 11A.
  • the front bottom segment 320, the back bottom segment 330, the front top segment 350 and the back top segment 360 have an identical shape, which is described hereafter under reference to the front top segment 350.
  • the front top segment 350 comprises wedge-shaped, convex wall portions 352 that continues into radial reinforcement ribs 353, a first flange 356 in the horizontal plane of symmetry U and a second flange 357 that extends along the semicircular circumference of the surface 352.
  • the front top segment 350 is provided with a recessed connection 354 for a sewage pipe.
  • the alternative biogas tank 301 is provided with three first intermediate bottom segments 340, 341, 342, three second intermediate bottom segments 343, 344, 345 and three intermediate top segments 370, 371, 372.
  • the first intermediate bottom segments 340, 341, 342 and the second intermediate bottom segments 343, 344, 345 have an identical shape, which is described hereafter under reference to the first intermediate bottom segment 340 at the front.
  • the first intermediate bottom segment 340 comprises an arched wall 373, as shown in figure 13, which describes a 105 degree circular section of the digester chamber 302.
  • the first intermediate bottom segment 340 is provided with a first radially extending flange 375 that extends along the lower side of the arched wall 373 in the longitudinal vertical plane of symmetry V, a second radially extending flange 376 that extends along the upper side of the arched wall 373, parallel to the longitudinal horizontal plane of symmetry U, and third radially extending flanges 377 that extends along the arched sides of the arched wall 373, parallel to the lateral vertical plane of symmetry W.
  • circumferential reinforcement ribs 501 are formed in the arched wall 373.
  • the three intermediate top segments 370, 371, 372 each comprise an arched wall 502 which describes a 150 degree section of the cylindrical digester chamber 302.
  • Each of the intermediate top segments 370-372 is provided with a first radiaaly extending flange 503 that extends along the first lower end of the arched wall 379 parallel to the horizontal plane of symmetry U, a second radially extending flange 504 that extends along the second lower end of the arched wall 502, parallel to the longitudinal horizontal plane of symmetry U, and third radially extending flanges 505 that extends along the arched sides of the arched wall 502, parallel to the lateral vertical plane of symmetry W.
  • circumferential reinforcement ribs 506 are formed
  • the first intermediate top segment 371 is provided with an outlet channel 304 that communicates between the digestion chamber 302 and the expansion chamber 303.
  • the third top segment 373 is provided with an inlet channel 305. As in the first biogas tank 1, the inlet channel 305 extends deeper into the digestion chamber 303 than the outlet channel 304.
  • the biogas tank 301 comprises multiple vertical wall segments 380 that are identically shaped. Two of the vertical wall segments 380 are placed near the front end cap 351 to form a vertical front wall 381. Two of the vertical wall segments 380 are placed near the back end cap 361 to form a vertical back wall 383. Between the vertical front wall 381 and the vertical back wall 383 six vertical wall segments 380 are arranged on each side of the intermediate top segments 370, 371, 372 to form two vertical side walls 385, 386, respectively. The front wall 381, the back wall 383 and the side walls 385, 386 together bound the open expansion chamber 303.
  • the vertical wall segments 380 form a quadrangular vertical shaft 390 that vertically extends the inlet channel 305 through the expansion chamber 303.
  • the vertical wall segments 380 comprise flanges along the outer circumference to mutually couple the segments 380.
  • the flanges at the bottom side are connected to supporting flanges 378 extending from the top segments 370, 371, 372.
  • additional vertical wall segments 380 can be added to scale or extend the expansion chamber 303 accordingly.
  • the intermediate bottom segments 340-345 and the intermediate top segments 370-372 are provided with a thin walled U-shaped profile 311 that is located at the transition from the arched walls into the third flanges.
  • the open end of the U-shaped profile 311 faces to the adjacent segment, the front end cap 351 or the back end cap 361.
  • the front end cap 351 and the back end cap 361 are provided which such U-shaped profile 311 along its circumference.
  • the U-shaped profile 311 bounds an elongated, continuous insert chamber 310 along the flanges, which in an assembled state holds a resilient, elongated seal 314, similar to the one depicted in figure 9B.
  • the elongated seal 314 seals the vertical connections between the intermediate segments, and between the outer intermediate segments and the end caps 351, 361.
  • Figure 16 shows in detail two first flanges 503 of two adjacent intermediate top segments 371, 372 placed on top of two second flanges 376 of two adjacent intermediate bottom segments 341, 342.
  • the flanges 503, 376 are provided with mutually aligned holes 403 such that the intermediate top segments and the intermediate bottom segments can be kept against each other by means of identical third couplings 400.
  • Figures 14A, 15A and 15B show one of the third couplings 400 in relation to coupling of the second flange 376 of one of the first intermediate bottom segments 341 to the first flange 503 of one of the intermediate top segments 371.
  • the third coupling 400 is shown in more detail in figures 15A and 15B.
  • the third coupling 400 is made of plastic, such as HDPE or a stronger plastic, and comprises a locking pin 410 and a wedge 430 which locks onto the locking pin 410 in the locking direction G.
  • the locking pin 410 is provided with an elongated, substantially rectangular shaft 412 that is dimensioned to snug fit through the aligned holes 403 of the adjacent flanges to be interconnected and at one end of the shaft 412 a convex head 411 which is dimensioned to abut against reinforcement ribs around the hole 403.
  • the shaft 412 When viewed from the head 411, the shaft 412 subsequently comprises a guiding section 413, a midsection 414 and a foot section 415.
  • the narrow midsection 414 is provided with recessed sides 418 that extend parallel to the locking direction G.
  • the recessed sides 418 are at a smaller distance from each other than the dimension of the width of the guiding section 413.
  • the foot section 415 is of similar width as the guiding section 413.
  • the guiding section 413 once inserted in insert direction H into the hole 403, is in is close proximity with the inner wall of the hole 403 in order to align the locking pin 410 in respect thereof.
  • the locking pin 410 is provided with tooth-shaped first locking edges 416 on the recessed sides 418 of the narrow midsection 414.
  • the first locking edges 416 extend in the longitudinal direction of the elongated shaft 412, parallel to the insert direction H and transverse to the locking direction G.
  • the vertical locking edges 416 form barbs facing in the locking direction G.
  • the 415 comprises tooth-shaped second locking edges 417 which extend outwards from both recessed sides 418.
  • the subsequent second locking edges 417 incline in the locking direction G, opposite to the insert direction H.
  • the second locking edges 417 form barbs facing in the locking direction G, and inclining opposite to the insert direction H.
  • the wedge 430 comprises a first wedge leg 431 and a second wedge leg 432 that are parallel to each other.
  • the wedge legs 431, 432 are connected to each other by a bridge section 433 to form a U-shaped body 434 with an accommodation space 439 therein for reception of the locking pin 410.
  • the wedge legs 431, 432 are provided with tooth-shaped third locking edges 435 which extend parallel to the insert direction H of the locking pin 410.
  • the third locking edges 435 form barbs facing opposite to the locking direction G.
  • the U-shaped body 434 has a flat top surface 436 for abutment with one of the flanges to be interconnected, opposite to the head 411 of the locking pin 410.
  • the wedge legs 431, 432 are provided with inclined surfaces 437 that taper or converge towards the flat top surface 436 in the locking direction G.
  • tooth-shaped fourth locking edges 438 are provided which form barbs facing in an opposite direction relative to the locking direction G.
  • the locking pin 410 is inserted in the insert direction H into one of the aligned holes 403 of the adjacent flanges.
  • the head 411 is brought into contact with the reinforcement ribs around the hole 403.
  • the wedge 430 can be placed around the locking pin 410 in the locking direction G, thereby wedging it between the flange surface and the foot section 415.
  • the first locking edges 416 and the second locking edges 419 of the locking pin 410 mesh with respectively the inverted third locking edges 435 and the inverted fourth locking edges 438 of the wedge 430.
  • the wedge 430 can only be advanced in the locking direction G, while movement in the opposite direction is blocked by the barbed shape of the locking edges 416, 419, 435, 438.
  • the meshing locking edges 416, 419, 435, 438 ratchet over each other, wedging the wedge 430 further between the foot section 415 and the flange surface around the hole 403.
  • the thickness of the wedge body 434 located vertically under the head 411 increases as the wedge 430 is moved in the locking direction G, thereby pulling the foot section 415 further in the insert direction H and tightening the coupling of the flanges between the head 411 and the foot section 415. In this manner the convex head 411 is biased from its convex shape into a flatter shape.
  • the second flange 376 of the intermediate bottom segment 344 and the first flange 503 of the intermediate top segment 371 are provided with respectively a first deformable seal strip 510 and a second deformable seal strip 511 that extend parallel to the longitudinal horizontal plane of symmetry U.
  • the deformable seal strips 510, 511 stand out from the surface of their respective flanges 376, 503 at an angle towards the digester chamber 302. During the tightening of the coupling 400, the flanges 376, 503 are pulled towards each other, thereby deforming the seal strips 510, 511 to the form as shown in figure 14A.
  • the seal strips 510, 511 form two seals between the flanges 376, 503 that prevent the escape of methane gas from within the digester chamber 302 through the horizontally extending connections between the segments.
  • the sealing effect of the seal strips 510, 511 is further increased as the level of the feedstock within the digester chamber 302 is kept high enough to keep the seal strips 510, 511 permanently submerged in the feedstock, so that the feed stock accumulates from within the digester chamber 302 against the seal strips 510, 511.
  • the third couplings 400 are equally distributed along all flanges to keep the flanges and thereby the segments tightly against each other over their entire length.
  • the first intermediate bottom segments 340, 341, 342, the second intermediate bottom segments 343, 344, 345 and the intermediate top segments 370, 371, 372 are assembled to form three intermediate circular ring segments which in turn form the circumferential wall around the cylindrical digester chamber 302 between the front end cap 351 and the back end cap 361.
  • the vertical wall segments 380 can alternatively also be interconnected by the use of the couplings as shown in figures 7A, 7B or 8.
  • Figure 18 shows a fourth, alternative coupling 600 which can be used in the modular biogas tank of figure 1 or the alternative biogas tank of figure 11A to couple any of the segments.
  • the fourth coupling 600 comprises a plastic locking pin 610 having an elongated round shaft 612 and a broader, circular flat head 611.
  • the shaft 612 comprises a beveled front 613, an elongated blind hole 615 that divides the shaft 612 into two resilient halves 616 having multiple circumferential locking edges 617 at the outer side.
  • the alternative biogas tank 301 comprises many identically shaped segments, enabling one and the same segment to be flipped over to be used at any other suitable position in the alternative biogas tank 301. Furthermore, additional intermediate segments can be added to form extension ring segments which extend the digester chamber 302 in the longitudinal direction.

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Abstract

The invention relates to a biogas system comprising an elongated tank forming an elongated internal digester chamber, wherein in its longitudinal direction the tank comprises in series a front end section, multiple intermediate sections and a back section that bound the digestion chamber, wherein the front end section, the intermediate sections and the back section comprises flanges that are coupled against each other.

Description

Biogas system
BACKGROUND
The invention relates to a biogas system. Biogas systems comprise a digestion chamber to contain a mixture of manure and other biodegradables, called feedstock, that is partly dissolved in water in order to produce methane gas. The methane gas can be used for household or small industrial purposes.
A known biogas system is build of bricks. As a closed dome of bricks is necessary to enclose the methane gas, a skilled mason has to be present at the building site and even a skilled mason has some weeks work to build one biogas system, and before building heavy bricks need to be supplied to the building site. A brick biogas system needs to be engineered for every size and every location separately. Once it is in place it size is fixed.
It is an object of the invention to provide a biogas system that can be provided in an efficient manner.
It is an object of the invention to provide a biogas system that can be assembled by low skilled people.
It is an object of the invention to provide a biogas system that can be easily scaled up. SUMMARY OF THE INVENTION
The invention provides a biogas system comprising an elongated tank forming an elongated internal digester chamber, wherein in its longitudinal direction the tank comprises in series a front end section, multiple intermediate sections and a back section that bound the digestion chamber, wherein the front end section, the intermediate sections and the back section comprises flanges that are coupled against each other.
The biogas system according to the invention can be supplied as separated sections which are subsequently assembled by coupling the flanges against each other. This can be done by low skilled people.
In an embodiment the intermediate sections comprise multiple intermediate segments which are positioned in series around the longitudinal axis of the tank, wherein at the meeting ends the intermediate segments comprise flanges that are coupled against each other. The intermediate sections can be formed by coupling the flanges thereof against each other on site. The intermediate segments can be transported to the assembly site in a compact manner.
In above mentioned embodiments the tank can be scaled up in its length by supplying the necessary amount of intermediate sections.
In an embodiment the intermediate segments comprise a deformable seal strip that is formed as one unity with the flange, wherein the deformable strip extends oblique from the flange with its distal end towards the digestion chamber. The deformable seal strip is oriented from the flange towards the digestion chamber and abut with its distal end the opposite flange to be coupled with. The feed stock in the digestion chamber can penetrate between the coupled flanges up to the seal strip, whereby it accumulates and further closes possible gaps between the coupled flanges. In an embodiment the biogas system comprises an expansion chamber above the top tank half that is separated from the digestion chamber and that is in fluid connection with the digestion chamber via an outlet channel only. The expansion chamber can store a fraction of the mixture that is expelled from the digestion chamber via the outlet channel due to the production of methane gas. The mass of the expelled fraction can keep the produced methane gas under some pressure.
In an embodiment the expansion chamber is open at the upper side, whereby the level of produced methane gas can be easily derived by notifying the level of the mixture in the expansion chamber by sight.
In an embodiment thereof is in horizontal direction the open upper side larger than the outlet channel .
In an embodiment the expansion chamber is bounded by a circumferential wall that extends upright from the tank. The circumferential wall can be provided together with the tank to be assembled thereon.
In an embodiment thereof the circumferential wall comprises a free extending upper edge that bounds the open upper side of the expansion chamber.
In an embodiment the circumferential wall comprises wall segments that are coupled against each other, wherein the transitions between the wall segments preferably coincide with the transitions between the intermediate sections. The wall segments can be easily scaled up together with the intermediate sections.
In an embodiment the tank comprises an upper wall that bounds the upper side of the digestion chamber and the lower side of the expansion chamber, wherein the outlet channel extends downwards from the upper wall into the digestion chamber. The lower side of the outlet channel thereby determines the maximum height of the methane gas body in the digester chamber. In this manner it is prevented that too much mixture is expelled towards the expansion chamber, and it is thereby also prevented that the gas pressure of the methane gas exceeds values beyond the specifications of the gas appliances that retrieve the methane gas from the digestion chamber.
In an embodiment thereof the flanges at the meeting ends of the intermediate sections extend in vertical direction all below the lowest end of the outlet channel, whereby the coupled flanges are continuously submerged into the feedstock. Thereby the abovementioned sealing action of the feedstock between the flanges is assured.
In an embodiment the tank comprises an upper wall that bounds the upper side of the digestion chamber, and an inlet channel that extends downwards from the upper wall into the digestion chamber, wherein the inlet channel is spaced apart from the outlet channel in the longitudinal direction of the tank. The inlet chamber allows the methane gas to be enclosed inside the digestion chamber while more feedstock can still be inserted in the digestion chamber.
In an embodiment thereof the outlet channel is separated from the expansion chamber, wherein the outlet channel is preferably upwardly extended by a circumferential wall that is located inside the expansion chamber.
In an embodiment the inlet channel extends in downward direction deeper inside the digestion chamber than the outlet channel, whereby superfluous methane gas will escape via the outlet channel only, thus keeping the inlet area free of methane gas.
In a constructive strong embodiment the intermediate tank sections form a cylindrical circumferential wall of the tank.
In an alternative embodiment the tank comprises a top tank half and a bottom tank half having horizontally extending flanges that are coupled against each other, wherein the top tank half comprises in series a front top segment, multiple intermediate top segments and a back top segment having vertically extending flanges that are coupled against each other, wherein the bottom tank half comprises in series a front bottom segment, multiple intermediate bottom segments and a back bottom segment having vertically extending flanges that are coupled against each other.
In an embodiment thereof the intermediate top segments and the intermediate bottom segments are identically formed, whereby these segment can be produced in an efficient manner.
In an embodiment the sections comprise a continuous insertion chamber along the flanges, wherein the insertion chambers of the coupled flanges are positioned straight opposite each other, wherein a common resilient sealing is inserted in the opposite insertion chambers. The inserted and enclosed resilient sealing seals the coupled flanges along the length, whereby the mixture and the produced methane gas remains enclosed inside the digestion chamber, at least to a large extent.
In an embodiment thereof the sections comprise a wall section between the flanges, and an U-shaped insertion profile for the sealing between the wall section and its flange, wherein the wall section connects to the back of the U-shaped insertion profile and the flange forms a continuation of one of the legs of the U-shaped insertion profile. The U-shaped insertion profile forms a clearly visual indication for the intended position of the seal, whereby can be ensured that the seal will be placed in the intended way.
In an embodiment thereof the resilient sealing comprises an elongated base strip having sealing flaps along the length of the base strip that extend sideways from the base strip.
In particular, the base strip and the sealing flaps are in cross section configured as arrow heads that point outside. The arrow heads indicate the intended insertion direction of the seal.
In an embodiment the flanges are coupled by multiple couplings that are evenly distributed along the flanges, wherein the couplings comprise a coupling pin having a coupling head and a coupling shaft extending from the coupling head, wherein the flanges comprise sets of aligned holes wherein the coupling shaft is inserted.
In an embodiment the couplings comprise a wedge having two wedge legs to accommodate the coupling shaft in between, wherein the wedge legs and the coupling shaft comprise a series of locking edges that incline with respect to the longitudinal axis of the shaft. The coupling can be tightened by bringing the coupling shaft further between the wedge legs by pushing the wedge towards the shaft. The inclined series of locking edges that are brought against each other provide the conversion of the sliding movement of the wedge transverse to the longitudinal direction of the coupling shaft into a tightening movement of the coupling head towards the wedge in the longitudinal direction of the coupling shaft.
In an embodiment thereof the locking edges are barbed shaped to enable the accommodation of the shaft between the wedge legs and to counteract disengagement. In this manner the couplings can be installed once by one way locking interaction between the locking shaft and the wedge.
The flanges that are coupled against each other can be biased towards each other when the coupling head has a convex shape and is configured to be biased towards a flatter shape when the wedge is tightened.
In preferred embodiments the sections or segments or couplings are made of plastic, preferably HDPE .
The various aspects and features described and shown in the specification can be applied, individually, wherever possible. These individual aspects, in particular the aspects and features described in the attached dependent claims, can be made subject of divisional patent applications .
BRIEF DESCRIPTION OF THE DRAWINGS The invention will be elucidated on the basis of an exemplary embodiment shown in the attached drawings, in which :
Figure 1 is an isometric view of a modular biogas tank according to the invention;
Figure 2 is an isometric view of the biogas tank according to figure 1, wherein the upper parts have been removed;
Figure 3 is an isometric view of the biogas tank according to figure 2, wherein some side parts have been removed;
Figure 4 and 5 are side views of the biogas tank according to figure 1, for different illustrating purposes;
Figure 6 is a back view of the biogas tank according to figure 1;
Figures 7A and 7B are a cross section and an isometric view of a first coupling of the biogas tank at the position as indicated in figure 2;
Figure 8 is a cross section of a second coupling for the biogas tank at the position as indicated in figure 2;
Figure 9A is a cross section of two wall segments and a seal at the position as indicated in figure 3;
Figure 9B is an isometric view of the seal according to figure 9A;
Figure 10 is a cross section of the wall of the biogas tank at the position as indicated in figure 2
Figure 11A is an isometric view of a second modular biogas tank according to the invention;
Figure 11B is an exploded view of the modular biogas tank according to figure 11A;
Figure 12 is a longitudinal section of the biogas tank according to figure 11A, for different illustrating purposes ;
Figure 13 is a cross section of the modular biogas tank according to the line XII-XII in figure 11A;
Figure 14A is a detail view of the modular biogas tank according to circle XIII in figure 13;
Figure 14B is an exploded view of the modular biogas tank according to figure 14A;
Figure 15A is an isometric view of a third coupling for the biogas tank;
Figure 15B is an exploded view of the coupling according to figure 15A;
Figure 16 is a detail view of the modular biogas tank according to circle XV in figure 11A;
Figure 17 is a cross section of the modular biogas tank according to the line XVI-XVI in figure 16; and
Figure 18 is an isometric view of a fourth coupling for use in the modular biogas tank of figure 1 or the alternative biogas tank of figure 11A.
DETAILED DESCRIPTION OF THE INVENTION
Figures 1, 4 and 6 show a first modular biogas tank 1 according to the invention. The elongated biogas tank 1 is destined to digest a mixture of manure and biodegradables, called feedstock, that is partly dissolved in water in order to produce methane gas under low pressure.
The biogas tank 1 comprises a front bottom segment 20, three intermediate bottom segments 40, 41, 42 and a back bottom segment 30, a front top segment 50, three intermediate top sections 70, 71, 72 and a back top segment 60 that are coupled along their sides to bound a closed digestion chamber 2. The biogas tank 1 further comprises two vertical side walls 80, 82, a vertical front wall 81, and a vertical back wall 83 on the top segments 50, 70, 71, 72, 60 to bound an open expansion chamber 3 having on top an overflow 84 above the digestion chamber 2. The back top segment 60 is provided with an inlet channel 5 that has been extended by a vertical shaft 90 aside the expansion chamber 3. The front top segment 50 is provided with an outlet channel 4 that communicates between the digestion chamber 2 and the expansion chamber 3. The segments are discussed in more detail hereafter, wherein reference is made to a horizontal plane of symmetry U, a longitudinal vertical plane of symmetry V and a lateral vertical plane of symmetry W of the outside shape of the biogas tank 1.
The front bottom segment 20, the back bottom segment 30, the front top segment 50 and the back top segment 60 have an identical outside shape, which is described hereafter under reference to the front top segment 50.
The front top segment 50 comprises a top wall section 59 extending parallel to the horizontal plane of symmetry U, an elongated straight front wall section 51 and two straight side wall sections 53 that together form a box- shaped stiffening construction, a second, substantially square straight front wall section 52 standing outwards from the middle of the elongated front wall section 52, two convex front wall sections 54 that extend between the square front wall section 52 and the elongated front wall section 51, and two convex side wall sections 55 below the straight side wall sections 53.
The front top segment 50 further comprises a first flange 56 that extends along the straight front wall section 51 and the convex wall sections 54, 55 in the horizontal plane of symmetry U, a second flange 57 that extends along the convex side walls 55 and the straight side walls 53 and a third flange 58 that extends along the straight top wall 59, both parallel to the lateral vertical plane of symmetry W.
The intermediate bottom segments 40, 41, 42 and the intermediate top segments 70, 71, 72 have an identical shape, which is described while referring to the second top segment 81 in figure 3.
The second top segment 81 comprises a straight, rectangular top wall 73 and two substantially square straight side walls 74 standing outwards from the top wall 73. The second top segment 80 further comprises first flanges 75 that extend along the lower side of the side walls 74 in the horizontal plane of symmetry U, second flanges 76 that extend along the sides of the side walls 74 and third flanges 77 that extend along the sides of the top wall 73, both parallel to the lateral vertical plane of symmetry W. Along the short corner sides of the top wall 73, the top segment 81 comprises upright insertion profiles 78 wherein the vertical side walls 80, 82 have been inserted.
Figure 9A shows in detail the second flange 57 of the front bottom segment 20 and the second flange 76 of the first intermediate bottom part 40, which are kept against each other by means of identical first couplings 100 of which one is shown in more detail in figure 7A. The couplings 100 are equally distributed along all flanges to keep the flanges and thereby the segments tightly against each other over their entire length.
As shown in figure 9A, the front bottom segment 20 and the first intermediate bottom segment 40 are both provided with a U-shaped profile 11 that at the outer side of the biogas tank 1 connects the respective wall section 53, 74 to the respective flange 57, 76, and at the inner side of the biogas tank 1 is connected to an end flange 12. The U-shaped profile 11 bounds an elongated, continuous insert chamber 10 along the flanges, wherein a resilient, elongated seal 14 has been inserted. The seal 14 is shown in detail before its insertion in figure 9B. The seal 14 comprises a flexible base strip 15 having for each insert chamber 10 an arrow-shaped side flap 16, a slim side flap 17 and a hollow side flap 18 on both sides of the base strip 15. The base strip 15 and the side flaps 16, 17, 18 are (co) extruded from rubber, preferably Nitrile Butadiene Rubber (NBR) , and form arrow heads that point in the direction of the bottom of the insert chamber 10.
As far as now described, the shape of each of the segments is symmetrical with regard to the planes of symmetry U, W, V.
The first coupling 100 comprises a circular hole 101 in the second flange 57 of the front bottom segment 20 and an annular protrusion 102 on the second flange 76 of the first intermediate bottom segment 40 that is confined in the circular hole 101 like a male-female connection to bring and keep the flanges 57, 76 aligned against each other in a fool proof manner. Inside the protrusion 102 there is a smaller hole 103 which is provided with a locking edge 104. The coupling 100 further comprises a plastic locking pin 110 which is shown in detail in figure 7B. The locking pin 110 comprises an elongated shaft 112 and a broader, circular flat head 111. The shaft 112 comprises a beveled front 113, two notches 114 on either side followed by an elongated hole 115 that divides the shaft 112 into two resilient halves 116 having multiple locking edges 117 at the outer side. The locking edges 104, 117 are designed such that the locking pin 110 immediately locks permanently after having been inserted into the smaller hole 103 in direction F, which lock can only be tightened further by pulling or pushing further in direction F.
Figure 8 shows an alternative, second coupling
200. The coupling 200 comprises the same circular hole 101 in the second flange 57 of the front bottom segment 20 and the annular protrusion 102 on the second flange 76 of the first intermediate bottom segment 40 that is confined in the circular hole 101 like a male-female connection to bring and keep the flanges 57, 76 aligned against each other in a fool proof manner. Inside the protrusion 102 there is a smaller hole 203. The coupling 200 further comprises a plastic locking pin 210 having an elongated shaft 212 and a broader, circular flat head 211. The shaft 212 comprises a beveled front 213, two notches 214 on either side followed by an elongated hole 215 that divides the shaft 212 into two resilient halves 216 having multiple locking edges 217 at the outer side. The second coupling further comprises a ring plate or cup spring 220 having a hole 218 which is provided with a locking edge 204. The locking edges 204, 217 are designed such that the locking pin 210 immediately locks permanently after having been inserted into the smaller hole 103 in the direction F, which lock can only be tightened further by pulling or pushing further in direction F, such as by means of the pulling side of a hammer head 300 that is supported on the cup spring 217 to bias the cup spring 220.
Per each segment 20, 30, 40, 41, 42, 50, 60, 70, 71, 72 the protrusions 102 and holes 103 are distributed such along the flanges that on the vertically extending flanges the holes 103 change into an protrusion 102 or reverse when passing the longitudinal vertical plane of symmetry V, and that for the horizontally extending flanges the holes 103 and protrusions 102 are opposite to each other when considered at the opposite sides of the longitudinal vertical plane of symmetry V. In this manner the intermediate segments 40, 41, 42, 70, 71, 72 all still are identically shaped, enabling one and the same intermediate segment to be flipped over in direction A or turned around its vertical axis in direction B as indicated in figure 3 to be used at any intermediate position of the biogas tank 1. On the same manner the front bottom segment 20 and the back bottom segment 30 are still identically shaped to be interchangeable by turning around its vertical axis in direction C as indicated in figure 3.
The front top segment 50 uniquely further comprises a rectangular outlet shaft 65 extending downwardly from the top wall 59 to bound the outlet 4. The outlet shaft 65 has a lower outlet edge 66 that extends parallel to and above the first flange 56. The back top segment 60 uniquely comprises a rectangular inlet shaft 67 to bound the inlet 5. The inlet shaft 67 has a lower inlet edge 68 that extends parallel to and above the first flange 56. In vertical direction, the lower outlet edge 68 extends below the lower inlet edge 66, over about 10 centimeter. The inlet edge 68 has a smaller cross section than the outlet edge 66 to prevent that pieces of the feedstock are thrown into the digestion chamber 2 cannot be taken out at the outlet 4 anymore. Both the front top segment 50 and the back top segment 60 are provided with upright insertion profiles 91, 95 wherein the vertical front wall 81 and the vertical back wall 83 have been inserted.
The segments 20, 30, 40, 41, 42, 50, 60, 70, 71, 72 have been manufactured by injection moulding of nitrogengas enclosing HDPE . A cross section of a wall section is shown in figure 10. The wall section encloses nitrogen bubbles in its centre and smaller nitrogen bubbles at both sides of the centre. The solid outside faces of the wall section are free of bubbles. The enclosed bubbles provide thermal insulation of the digester chamber 2.
The methane forming process inside the digester chamber 2 is explained under reference to figure 5. The digester chamber 2 is fully filled by insertion of a mixture of water and feedstock via the inlet shaft 67, at a maximum level E some centimeters from the dome that is formed by the upper wall sections 59, 73. The mixture starts to generate methane gas, which escapes from the mixture and stays enclosed in the digestion chamber 2 to push down the level of the mixture. The lowest level D is determined by the height of the lower edge 66 of the outlet shaft 65, as the gas will escape via the outlet when the level has reached the lower edge 66. During lowering the level, the surplus of mixture is pushed into the expansion chamber 3 via the outlet 5. The mass of the expelled mixture keeps the enclosed methane gas under pressure, which pressure is enough to force the methane gas into a hose 700 that is connected to the top side of the digester chamber 2. The overflow 84 ensures that when the expansion chamber reaches its maximum level, the mixture is expelled in a controlled manner .
At the lowest level D the mixture in the digester chamber 2 occupies 75% of the total volume of the digester chamber 2. That is, the total volume of the stored methane gas can be 25% of the total volume of the digester chamber 2. The maximum volume of the expansion chamber 3 is 25% of the volume of the digester chamber 2 as well. The entire biogas tank 1 can be scaled up or down only by adding or removing some identical intermediate segments 40, 70. In this manner the above mentioned volume rates will remain the same. For this purpose the vertical side walls 80, 82 are formed of interconnected side wall sections of which the interconnections coincide with the transitions between the top sections 50, 70, 71, 72, 60. The intermediate segments, and the front segments and the back segments can be stacked and nested in themselves, allowing the biogas tank 1 to be transported as a compact package to its place where it will be assembled and employed.
Figures 11A, 11B, 12 and 13 show a second modular biogas tank 301 according to the invention. The biogas tank 301 is assembled out of segments, the form of which will be described hereafter. The segments have been manufactured by injection molding HDPE, and have a substantially constant wall thickness over their entirety. As shown in figure 12, the segments enclose a straight circular cylindrical digester chamber 302 and an expansion chamber 303 with the same functionality as the ones described in relation to the first biogas tank 1 of figures 1, 4 and 6, utilizing the same methane forming process as described above.
The segments are discussed in more detail hereafter, wherein reference is made to a horizontal plane of symmetry U, a longitudinal vertical plane of symmetry V and a lateral vertical plane of symmetry W of the outside shape of the alternative biogas tank 301.
Figure 11B shows in exploded view that the biogas tank 301 comprises a semicircular front bottom segment 320 and a semicircular front top segment 350 which together form a circular front end cap 351 for the digester chamber 302, and a semicircular back top segment 360 which together form a circular back end cap 361 for the digester chamber 302 as shown in figure 11A. The front bottom segment 320, the back bottom segment 330, the front top segment 350 and the back top segment 360 have an identical shape, which is described hereafter under reference to the front top segment 350. The front top segment 350 comprises wedge-shaped, convex wall portions 352 that continues into radial reinforcement ribs 353, a first flange 356 in the horizontal plane of symmetry U and a second flange 357 that extends along the semicircular circumference of the surface 352. The front top segment 350is provided with a recessed connection 354 for a sewage pipe.
As shown in figure 11B, the alternative biogas tank 301 is provided with three first intermediate bottom segments 340, 341, 342, three second intermediate bottom segments 343, 344, 345 and three intermediate top segments 370, 371, 372. The first intermediate bottom segments 340, 341, 342 and the second intermediate bottom segments 343, 344, 345 have an identical shape, which is described hereafter under reference to the first intermediate bottom segment 340 at the front. The first intermediate bottom segment 340 comprises an arched wall 373, as shown in figure 13, which describes a 105 degree circular section of the digester chamber 302. The first intermediate bottom segment 340 is provided with a first radially extending flange 375 that extends along the lower side of the arched wall 373 in the longitudinal vertical plane of symmetry V, a second radially extending flange 376 that extends along the upper side of the arched wall 373, parallel to the longitudinal horizontal plane of symmetry U, and third radially extending flanges 377 that extends along the arched sides of the arched wall 373, parallel to the lateral vertical plane of symmetry W. In the arched wall 373 circumferential reinforcement ribs 501 are formed.
As shown in figures 11B and 13, the three intermediate top segments 370, 371, 372 each comprise an arched wall 502 which describes a 150 degree section of the cylindrical digester chamber 302. Each of the intermediate top segments 370-372 is provided with a first radiaaly extending flange 503 that extends along the first lower end of the arched wall 379 parallel to the horizontal plane of symmetry U, a second radially extending flange 504 that extends along the second lower end of the arched wall 502, parallel to the longitudinal horizontal plane of symmetry U, and third radially extending flanges 505 that extends along the arched sides of the arched wall 502, parallel to the lateral vertical plane of symmetry W. In the arched wall 502 circumferential reinforcement ribs 506 are formed
The first intermediate top segment 371 is provided with an outlet channel 304 that communicates between the digestion chamber 302 and the expansion chamber 303. The third top segment 373 is provided with an inlet channel 305. As in the first biogas tank 1, the inlet channel 305 extends deeper into the digestion chamber 303 than the outlet channel 304.
As shown in figure 11B, the biogas tank 301 comprises multiple vertical wall segments 380 that are identically shaped. Two of the vertical wall segments 380 are placed near the front end cap 351 to form a vertical front wall 381. Two of the vertical wall segments 380 are placed near the back end cap 361 to form a vertical back wall 383. Between the vertical front wall 381 and the vertical back wall 383 six vertical wall segments 380 are arranged on each side of the intermediate top segments 370, 371, 372 to form two vertical side walls 385, 386, respectively. The front wall 381, the back wall 383 and the side walls 385, 386 together bound the open expansion chamber 303. Four vertical wall segments 380 form a quadrangular vertical shaft 390 that vertically extends the inlet channel 305 through the expansion chamber 303. The vertical wall segments 380 comprise flanges along the outer circumference to mutually couple the segments 380. The flanges at the bottom side are connected to supporting flanges 378 extending from the top segments 370, 371, 372. When the biogas tank 301 is extended by additional intermediate segments, additional vertical wall segments 380 can be added to scale or extend the expansion chamber 303 accordingly.
As shown in figure 16 and 17, the intermediate bottom segments 340-345 and the intermediate top segments 370-372 are provided with a thin walled U-shaped profile 311 that is located at the transition from the arched walls into the third flanges. The open end of the U-shaped profile 311 faces to the adjacent segment, the front end cap 351 or the back end cap 361. The front end cap 351 and the back end cap 361 are provided which such U-shaped profile 311 along its circumference. The U-shaped profile 311 bounds an elongated, continuous insert chamber 310 along the flanges, which in an assembled state holds a resilient, elongated seal 314, similar to the one depicted in figure 9B. The elongated seal 314 seals the vertical connections between the intermediate segments, and between the outer intermediate segments and the end caps 351, 361.
Figure 16 shows in detail two first flanges 503 of two adjacent intermediate top segments 371, 372 placed on top of two second flanges 376 of two adjacent intermediate bottom segments 341, 342. The flanges 503, 376 are provided with mutually aligned holes 403 such that the intermediate top segments and the intermediate bottom segments can be kept against each other by means of identical third couplings 400. Figures 14A, 15A and 15B show one of the third couplings 400 in relation to coupling of the second flange 376 of one of the first intermediate bottom segments 341 to the first flange 503 of one of the intermediate top segments 371. The third coupling 400 is shown in more detail in figures 15A and 15B.
The third coupling 400 is made of plastic, such as HDPE or a stronger plastic, and comprises a locking pin 410 and a wedge 430 which locks onto the locking pin 410 in the locking direction G. The locking pin 410 is provided with an elongated, substantially rectangular shaft 412 that is dimensioned to snug fit through the aligned holes 403 of the adjacent flanges to be interconnected and at one end of the shaft 412 a convex head 411 which is dimensioned to abut against reinforcement ribs around the hole 403. When viewed from the head 411, the shaft 412 subsequently comprises a guiding section 413, a midsection 414 and a foot section 415. The narrow midsection 414 is provided with recessed sides 418 that extend parallel to the locking direction G. In a direction transverse to the locking direction G, the recessed sides 418 are at a smaller distance from each other than the dimension of the width of the guiding section 413. The foot section 415 is of similar width as the guiding section 413. The guiding section 413, once inserted in insert direction H into the hole 403, is in is close proximity with the inner wall of the hole 403 in order to align the locking pin 410 in respect thereof. The midsection
414 and the foot section 415 extend through and out of the hole 403 at the side of the flanges opposite to the head 411.
The locking pin 410 is provided with tooth-shaped first locking edges 416 on the recessed sides 418 of the narrow midsection 414. The first locking edges 416 extend in the longitudinal direction of the elongated shaft 412, parallel to the insert direction H and transverse to the locking direction G. The vertical locking edges 416 form barbs facing in the locking direction G. The foot section
415 comprises tooth-shaped second locking edges 417 which extend outwards from both recessed sides 418. The subsequent second locking edges 417 incline in the locking direction G, opposite to the insert direction H. The first locking edges
416 merge into the second locking edges 417. The second locking edges 417 form barbs facing in the locking direction G, and inclining opposite to the insert direction H.
The wedge 430 comprises a first wedge leg 431 and a second wedge leg 432 that are parallel to each other. At one end, the wedge legs 431, 432 are connected to each other by a bridge section 433 to form a U-shaped body 434 with an accommodation space 439 therein for reception of the locking pin 410. At the mutually facing sides the wedge legs 431, 432 are provided with tooth-shaped third locking edges 435 which extend parallel to the insert direction H of the locking pin 410. The third locking edges 435 form barbs facing opposite to the locking direction G. The U-shaped body 434 has a flat top surface 436 for abutment with one of the flanges to be interconnected, opposite to the head 411 of the locking pin 410. At the side of the U-shaped body 434 that faces away from the flanges to be interconnected, the wedge legs 431, 432 are provided with inclined surfaces 437 that taper or converge towards the flat top surface 436 in the locking direction G. Along the he inclined surfaces 437 tooth-shaped fourth locking edges 438 are provided which form barbs facing in an opposite direction relative to the locking direction G.
In order to couple the flanges of two adjacent segments of the alternative biogas tank 301, first the locking pin 410 is inserted in the insert direction H into one of the aligned holes 403 of the adjacent flanges. The head 411 is brought into contact with the reinforcement ribs around the hole 403. With the narrow midsection 414 and the foot section 415 of the locking pin 410 sticking out of the other end of the hole 403, opposite to the head 411, the wedge 430 can be placed around the locking pin 410 in the locking direction G, thereby wedging it between the flange surface and the foot section 415.
As shown in figure 14A, the first locking edges 416 and the second locking edges 419 of the locking pin 410 mesh with respectively the inverted third locking edges 435 and the inverted fourth locking edges 438 of the wedge 430. As a result of this meshing, the wedge 430 can only be advanced in the locking direction G, while movement in the opposite direction is blocked by the barbed shape of the locking edges 416, 419, 435, 438. By pushing or pulling the wedge 430 further in the locking direction G, the meshing locking edges 416, 419, 435, 438 ratchet over each other, wedging the wedge 430 further between the foot section 415 and the flange surface around the hole 403. Because of the wedge shape of the wedge legs 431, 432, the thickness of the wedge body 434 located vertically under the head 411 increases as the wedge 430 is moved in the locking direction G, thereby pulling the foot section 415 further in the insert direction H and tightening the coupling of the flanges between the head 411 and the foot section 415. In this manner the convex head 411 is biased from its convex shape into a flatter shape.
As shown in figure 14B, the second flange 376 of the intermediate bottom segment 344 and the first flange 503 of the intermediate top segment 371 are provided with respectively a first deformable seal strip 510 and a second deformable seal strip 511 that extend parallel to the longitudinal horizontal plane of symmetry U. The deformable seal strips 510, 511 stand out from the surface of their respective flanges 376, 503 at an angle towards the digester chamber 302. During the tightening of the coupling 400, the flanges 376, 503 are pulled towards each other, thereby deforming the seal strips 510, 511 to the form as shown in figure 14A. The seal strips 510, 511 form two seals between the flanges 376, 503 that prevent the escape of methane gas from within the digester chamber 302 through the horizontally extending connections between the segments. The sealing effect of the seal strips 510, 511 is further increased as the level of the feedstock within the digester chamber 302 is kept high enough to keep the seal strips 510, 511 permanently submerged in the feedstock, so that the feed stock accumulates from within the digester chamber 302 against the seal strips 510, 511.
The third couplings 400 are equally distributed along all flanges to keep the flanges and thereby the segments tightly against each other over their entire length. With a plurality of the third couplings 400, the first intermediate bottom segments 340, 341, 342, the second intermediate bottom segments 343, 344, 345 and the intermediate top segments 370, 371, 372 are assembled to form three intermediate circular ring segments which in turn form the circumferential wall around the cylindrical digester chamber 302 between the front end cap 351 and the back end cap 361. The vertical wall segments 380 can alternatively also be interconnected by the use of the couplings as shown in figures 7A, 7B or 8.
Figure 18 shows a fourth, alternative coupling 600 which can be used in the modular biogas tank of figure 1 or the alternative biogas tank of figure 11A to couple any of the segments. The fourth coupling 600 comprises a plastic locking pin 610 having an elongated round shaft 612 and a broader, circular flat head 611. The shaft 612 comprises a beveled front 613, an elongated blind hole 615 that divides the shaft 612 into two resilient halves 616 having multiple circumferential locking edges 617 at the outer side.
In a similar manner as with the biogas tank 1 of figures 1, 4 and 6, the alternative biogas tank 301 comprises many identically shaped segments, enabling one and the same segment to be flipped over to be used at any other suitable position in the alternative biogas tank 301. Furthermore, additional intermediate segments can be added to form extension ring segments which extend the digester chamber 302 in the longitudinal direction.
It is to be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the spirit and scope of the present invention .

Claims

C L A I M S
1. Biogas system comprising an elongated tank forming an elongated internal digester chamber, wherein in its longitudinal direction the tank comprises in series a front end section, multiple intermediate sections and a back section that bound the digestion chamber, wherein the front end section, the intermediate sections and the back section comprises flanges that are coupled against each other.
2. Biogas system according to claim 1, wherein the intermediate sections comprise multiple intermediate segments which are positioned in series around the longitudinal axis of the tank, wherein at the meeting ends the intermediate segments comprise flanges that are coupled against each other.
3. Biogas system according to claim 2, wherein the intermediate segments comprise a deformable seal strip that is formed as one unity with the flange, wherein the deformable strip extends oblique from the flange with its distal end towards the digestion chamber.
4. Biogas system according to any one of the preceding claims, comprising an expansion chamber above the top tank half that is separated from the digestion chamber and that is in fluid connection with the digestion chamber via an outlet channel.
5. Biogas system according to claim 4, wherein the expansion chamber is open at the upper side.
6. Biogas system according to claim 5, wherein in horizontal direction the open upper side is larger than the outlet channel.
7. Biogas system according to any one of claims 4-6, wherein the expansion chamber is bounded by a circumferential wall that extends upright from the tank.
8. Biogas system according to claims 5 and 7, wherein the circumferential wall comprises a free extending upper edge that bounds the open upper side of the expansion chamber .
9. Biogas system according to claim 7 or 8, wherein the circumferential wall comprises wall segments that are coupled against each other.
10. Biogas system according to claim 9, wherein the transitions between the wall segments coincide with the transitions between the intermediate sections.
11. Biogas system according to any one of the claims 4-10, wherein the tank comprises an upper wall that bounds the upper side of the digestion chamber and the lower side of the expansion chamber, wherein the outlet channel extends downwards from the upper wall into the digestion chamber .
12. Biogas system according to claims 2 and 12, wherein in vertical direction the flanges at the meeting ends of the intermediate sections all extend below the lowest end of the outlet channel.
13. Biogas system according to any one of the claims 4-12, wherein the tank comprises an upper wall that bounds the upper side of the digestion chamber, and an inlet channel that extends downwards from the upper wall into the digestion chamber, wherein the inlet channel is spaced apart from the outlet channel in the longitudinal direction of the tank.
14. Biogas system according to claims 4 and 13, wherein the outlet channel is separated from the expansion chamber .
15. Biogas system according to claim 14, wherein the outlet channel is upwardly extended by a circumferential wall that is located inside the expansion chamber.
16. Biogas system according to claims 4 and 13, wherein in downward direction the inlet channel extends deeper inside the digestion chamber than the outlet channel.
17. Biogas system according to any one of the preceding claims, wherein the intermediate tank sections form a cylindrical circumferential wall of the tank.
18. Biogas system according to any one of the preceding claims, wherein the tank comprises a top tank half and a bottom tank half having horizontally extending flanges that are coupled against each other, wherein the top tank half comprises in series a front top segment, multiple intermediate top segments and a back top segment having vertically extending flanges that are coupled against each other, wherein the bottom tank half comprises in series a front bottom segment, multiple intermediate bottom segments and a back bottom segment having vertically extending flanges that are coupled against each other.
19. Biogas system according to claim 18, wherein the intermediate top segments and the intermediate bottom segments are identically formed.
20. Biogas system according to any one of the preceding claims, wherein the sections comprise a continuous insertion chamber along the flanges, wherein the insertion chambers of the coupled flanges are positioned straight opposite each other, wherein a common resilient sealing is inserted in the opposite insertion chambers.
21. Biogas system according to claim 20, wherein the sections comprise a wall section between the flanges, and an U-shaped insertion profile for the sealing between the wall section and its flange, wherein the wall section connects to the back of the U-shaped insertion profile and the flange forms a continuation of one of the legs of the U- shaped insertion profile.
22. Biogas system according to claim 20 or 21, wherein the resilient sealing comprises an elongated base strip having sealing flaps along the length of the base strip that extend sideways from the base strip.
23. Biogas system according to claim 22, wherein the base strip and the sealing flaps are in cross section configured as arrow heads that point outside.
24. Biogas system according to any one of the preceding claims, wherein the flanges are coupled by multiple couplings that are evenly distributed along the flanges, wherein the couplings comprise a coupling pin having a coupling head and a coupling shaft extending from the coupling head, wherein the flanges comprise sets of aligned holes wherein the coupling shaft is inserted.
25. Biogas system according to claim 24, wherein the couplings comprise a wedge having two wedge legs to accommodate the coupling shaft in between, wherein the wedge legs and the coupling shaft comprise a series of locking edges that incline with respect to the longitudinal axis of the shaft.
26. Biogas system according to claim 25, wherein the locking edges are barbed shaped to enable the accommodation of the shaft between the wedge legs and to counteract disengagement.
27. Biogas system according to any one of claims
24-26, wherein the coupling head has a convex shape and is configured to be biased towards a flatter shape when the wedge is tightened.
28. Biogas system according to any one of claims 24-27, wherein the couplings are made of plastic, preferably
HDPE.
29. Biogas according to any one of the preceding claims, wherein the sections or segments are made of plastic, preferably HDPE. o-o-o-o-o-o-o-o-
FG/HZ
PCT/NL2011/050472 2010-06-30 2011-06-30 Biogas system WO2012002813A1 (en)

Priority Applications (2)

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AP2013006688A AP3498A (en) 2010-06-30 2011-06-30 Biogas system
CN201180032803.XA CN103003410B (en) 2010-06-30 2011-06-30 Biogas system

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NL2005004A NL2005004C2 (en) 2010-06-30 2010-06-30 Biogas system.
NL2005004 2010-06-30

Publications (1)

Publication Number Publication Date
WO2012002813A1 true WO2012002813A1 (en) 2012-01-05

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AP (1) AP3498A (en)
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WO (1) WO2012002813A1 (en)

Cited By (3)

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Publication number Priority date Publication date Assignee Title
US20120005947A1 (en) * 2010-07-08 2012-01-12 Gardner Manufacturing Co.,Inc. Pest Control Device with Glueboard Guide
US20120174470A1 (en) * 2010-07-08 2012-07-12 Gardner Manufacturing Co., Inc. Pest control device with glueboard guide
CN103421848A (en) * 2013-07-12 2013-12-04 盐城市新洋农业试验站 Annular kiln type dry type biogas fermentation method

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104531510B (en) * 2014-12-29 2016-08-24 张万俊 Modified plastics horizontal full gravity flow high-position backflow stirring solar temperature-raising marsh pool

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Publication number Priority date Publication date Assignee Title
JPS5420419A (en) * 1977-07-18 1979-02-15 Hitachi Ltd Large tank
FR2502174A1 (en) * 1981-03-23 1982-09-24 Royer Michel Horizontal cylindrical digester to produce methane from organic waste - in baskets which can be changed without interrupting gas prodn.
EP1533252A2 (en) * 2003-11-21 2005-05-25 ZETAPLAST S.r.l. Method for making a large storage container of moulded plastics for use underground and large storage container thus obtained
US20080067179A1 (en) * 2006-09-04 2008-03-20 Graf Plastics Gmbh, A German Corporation Water tank and method for manufacturing a water tank
CN101603002A (en) * 2009-06-19 2009-12-16 昆明普尔顿管业有限公司 Combined biogas pool

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5420419A (en) * 1977-07-18 1979-02-15 Hitachi Ltd Large tank
FR2502174A1 (en) * 1981-03-23 1982-09-24 Royer Michel Horizontal cylindrical digester to produce methane from organic waste - in baskets which can be changed without interrupting gas prodn.
EP1533252A2 (en) * 2003-11-21 2005-05-25 ZETAPLAST S.r.l. Method for making a large storage container of moulded plastics for use underground and large storage container thus obtained
US20080067179A1 (en) * 2006-09-04 2008-03-20 Graf Plastics Gmbh, A German Corporation Water tank and method for manufacturing a water tank
CN101603002A (en) * 2009-06-19 2009-12-16 昆明普尔顿管业有限公司 Combined biogas pool

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120005947A1 (en) * 2010-07-08 2012-01-12 Gardner Manufacturing Co.,Inc. Pest Control Device with Glueboard Guide
US20120174470A1 (en) * 2010-07-08 2012-07-12 Gardner Manufacturing Co., Inc. Pest control device with glueboard guide
CN103421848A (en) * 2013-07-12 2013-12-04 盐城市新洋农业试验站 Annular kiln type dry type biogas fermentation method
CN103421848B (en) * 2013-07-12 2019-04-23 盐城市新洋农业试验站 Annular kiln formula biogas dry fermentation method

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CN103003410B (en) 2015-03-25
CN103003410A (en) 2013-03-27
NL2005004C2 (en) 2012-01-03
AP3498A (en) 2015-12-31

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