WO1995005451A2

WO1995005451A2 - Method and apparatus for mixing of fluid biomass in a bioreactor, especially in the presence of mesophilic and/or thermophilic micro-organisms obtaining the methane gas simultaneously

Info

Publication number: WO1995005451A2
Application number: PCT/PL1994/000015
Authority: WO
Inventors: Miros$m(D)aw SZUSTER
Original assignee: Przedsiebiorstwo Komunalne 'aqua' S.A.; Wojewódzki Fundusz Ochrony S^´Rodowiska I Gospodarki Wodnej
Priority date: 1993-08-13
Filing date: 1994-08-16
Publication date: 1995-02-23
Also published as: PL300077A1; AU7391794A; PL176200B1; WO1995005451A3

Abstract

The manner according to the invention consists in: the mixing occurs in two successive phases: the rising phase - during which the biomass is led to the upper tank (1) through the ascent pipe (2) into the upper tank (1) and the recirculation phase during which the biomass swelled before is introduced into the upper part of the bioreactor (5). The apparatus according to the invention has the upper tank (1), inside which the upper ending of the ascent pipe (2) is placed and out of which at least one recirculating pipe (3) closed return is led out.

Description

METHOD AND APPARATUS FOR MIXING OF FLUID BIOMASS IN A BIOREACTOR, ESPECIALLY IN THE PRESENCE OF MESOPHILIC AND/OR THERMOPHILIC MICRO-ORGANISMS OBTAINING THE METHANE GAS SIMULTANEOUSLY

Technical field.

The subject of the invention is a method and an apparatus for mixing of fluid biomass in the bioreactor, especially in the presence of mezophyllic and/or thermophyllic

micro-organisms and obtaining the methane gas

simultaneously, and particularly for mixing of waste sediments in specified closed fermentation chambers.

State of technique.

There are known and commonly used the methods of biomass mixing in the bioreactor, in which the biomass is moving from the bottom of the bioreactor to the upper part of it through an ascent pipe by means of gas that is introduced into it or by means of a rotation of a propeller installed in it. The most frequent solution of mixing of the biomass applied predominantly, in a specified closed fermentation chamber, is the ascent pipe and a helical agitator mounted in its upper part. The helical agitator is installed the most often on a solid floor at the bioreactor axis. The flow of biomass in the ascent pipe occurs from bottom to top with the possibility of the change of sense of rotation of the helical agitator and the change of direction of biomass flow i.e. from top to bottom. When the biomass flows in the ascent pipe from bottom to top, the biomass of larger specific density taken from the bottom part of the reactor is thrown onto a floating layers of lower density. Thereby a submergence of floating layers occurs that accelerates the digestion of organic matter. Consecutive changes of the sense of rotation of the helical agitator, cause that a surface scum gathered in the upper part of the bioreactor is forced into the lower biomass layers in the bioreactor by means of the ascent pipe. In such a manner an additional destruction of the scum layers occurs. If a heat exchanger is installed onto the ascent pipe, than the biomass mixing is connected with heating of bioreactor and the biomass comprised in it.

The disadvantage of this method is a fact , that for reactors of high volume, the biomass mixing by usage of the ascent pipe is sufficiently only for the destruction of the floating biomass layers but is insufficient for precise mixing and homogenising of biomass in whole bioreactor volume. Besides, the helical agitator in a less or greater degree , causes breaking of sediment floes , that leads to disturbances of fermentation process of biomass in the bioreactor, and next diminishes the bioreactor output. When such a such method of mixing is used the difficulties in precise mixing of bioreactor contents consists in necessity of high power mixing equipment. To destroy the floes and cause a swirl of biomass in the bioreactor one needs a large amount of energy in a short time. Even in the case of a periodical mixing of biomass in the bioreactor one needs electrical terminals of high powers . Therefore the additional mixing, systems are installed in the bioreactors of large volumes for instance pumps, associated with a heating system of the biomass in bioreactor. The helical mixer also needs a good damping of vibrations transmitted from it onto a solid floor of the bioreactor.

Disclosure of the invention.

The manner according to the invention consists in mixing in two phases , one after the other : in an ascent phase - during which the biomass under increasing gas pressure at the upper part of bioreactor and / or under decreasing gas pressure at the upper tank is transported through the bottom end of the ascent pipe into the upper tank, where the process of biomass swelling occurs - and in a recirculation phase during which at least a majority of the biomass swelled before at the upper tank, is put into the upper layers of biomass being in bioreactor under an influence of hydrostatic pressure or both, hydrostatic pressure and increased gas pressure at the upper tank. The duration time of the recirculation phase is shorter than the rising phase time . The rising phase begins after gas-tight closing of the bioreactor, and the recirculation phase starts from the moment of gas drainage from the bioreactor. The bioreactor becomes closed gas-tightly at the moment of the achievement by the biomass a lower level of tankage at the upper tank. As a result of gas production and / or gas supplied in to the bioreactor in an artificial manner, the biomass is displaced by gas to the upper tank, causing an increase in biomass tankage at the upper tank. Gas from the bioreactor is drained off when the biomass reaches a higher level of tankage at the upper tank or when the biomass reaches a minimal level of tankage at the bioreactor as a result of that, the gas pressure at bioreactor decreases and in the place of the gas drained off from the bioreactor , the biomass from the upper tank is transported under its hydrostatic pressure, resulting the diminishing of the biomass filling at the upper tank and increasing the bioreactor filling ,and again the level of the biomass at the upper tank reaches the lower state of filling. At the moment when biomass in the upper tank in the bioreactor reaches a higher state of filling or when the biomass in the bioreactor reaches minimal level of filling at bioreactor, the gas from the bioreactor flows to the upper tank or to the gas holder and / or equalising pressure tank. In the case of an other he kind of manner according to the invention, the rising phase begins at the moment of gas draining off from the upper tank and the recirculation phase starts at the moment when the gas is supplied to the upper tank. The gas drainage off from the upper tank is performed when the biomass achieves the lower level of filling at the upper tank, as a result of that, in the upper tank a negative pressure arises, that causes the biomass suction into it from the bioreactor, and owing to that, the state in the biomass filling of the upper tank increases. At the moment when the higher level of filling is reached in the upper tank or if the minimal level of biomass is reached in the bioreactor , the gas is directed into the upper tank. Consequently, the pressure in the upper tank increases and the biomass is moved from the upper tank to the bioreactor under the hydrostatic pressure or under the influence of its hydrostatic pressure and enhanced pressure in the upper tank. Therefore the state of filling in the upper tanks falls, and in the bioreactor increases, and after that again the biomass reaches the lower level of tankage at the upper tank. During the rising phase the gas from the upper tank is drained and introduced into the bioreactor, and during the recirculating phase the gas from bioreactor and/or gasholder is turned back into the upper tank. During the rising phase, the gas drained off from the upper tank can be compressed in a pressure tank and in the recirculating phase the compressed gas from the pressure tank can be supplied into the upper tank and / or to the ascent pipe. The fresh ration of the biomass or fresh ration of the biomass mixed before with biomass from the bioreactor is supplied to the bottom of the ascent pipe during the rising phase. The fresh portion of the biomass or fresh portion of the biomass mixed before with the biomass from the bioreactor can also be supplied directly to the upper tank.

In the apparatus according to the invention, the upper end of the ascent pipe is placed in the upper tank, from which at least one recirculation pipe closed in return manner for returning the biomass from the upper tank to the upper part of the bioreactor. The upper tank is placed inside and / or above the bioreactor and is equipped with a branch pipe for the gas drainage off or in the upper end of the ascent pipe protrudes above the bottom of the upper tank. The bottom of the upper tank is realised advantageously in the shape of truncated cone. The upper end of the ascent pipe is ended with an open hopper broadened to the upper edge, which is situated on the height equal to or lower than the higher level of the state of filling of the upper tank by the biomass. At least one over flow connection is led out from the side wall of the open hopper. The upper end of the ascent pipe can protrude over the level of higher state of the biomass filling in the upper tank , as well as it can be ended by a nozzle, above which a the mixing pipe is placed coaxially. The upper broadened end of this pipe is placed in the upper tank between the level of lower state of filling and the level of higher state of filling by the biomass. At least one of the recirculating pipes has a return water seal. The inlet of recirculation pipe is placed in the lower part of the upper tank below minimal level of biomass in the bioreactor or above this level with additional curve of the recirculation pipe towards the bottom , below the minimal filling level of the bioreactor. The highest outlet of the recirculation pipe is placed in the upper part of the bioreactor above the normal position of the biomass filling level in the bioreactor. The height of the return water-seal is larger than the distance between the lowest edge or a hole of the ascent pipe placed in the upper tank and the normal position of the biomass level in bioreactor, above which this edge or hole is situated. At least one from the outlets of the recirculation pipe is immersed in the bioreactor below the minimal level of biomass filling and by a vertical stub pipe is connected with at least one outlet of this pipe placed above the normal biomass filling level, the diameter of this stub pipe is smaller than the diameter of the recirculation pipe. The outlets of the recirculation pipe placed above the normal biomass filling level in the bioreactor are ended with side stub pipes, which ends are placed above the normal biomass filling level in the bioreactor. The lower end of the vertical stub pipe is connected with an upper pipe rim having the side channels placed on its circumference. The side channels of the upper pipe rim in the vertical projection from the top, branch out in the same direction from the internal as well as external surface of the upper pipe rim under the acute angle in relation to these surfaces, in order to cause an rotary motion of the biomass in the bioreactor round its axis of symmetry. The upper pipe rim is connected with a circulating branch with a circulating pump attached on it with the lower pipe rim, out of which external and internal surface are led out skew channels, that in the vertical projection are directed into the opposite direction in relation to the side channels of the upper pipe rim. The heat exchanger and / or heating elements are installed on the circulating branch . The bottom ends of the recirculation pipes in the vertical projection are tangent to the internal circle of the upper tank of the diameter larger than the diameter of the ascent pipe and they lay nearby it . The upper endings of the recirculating pipes are bent approximately under the right angle and turned advantageously under the acute angle to the level . The upper endings of the recirculating pipes can be underslung to the floor of the bioreactor by usage of flexible connectors. A supply pipe is led to the lower part of the ascent pipe. An injector of sucking a biomass from bioreactor through the suction stub pipe is installed on the supplying pipe. The suction stub pipe is connected with a lower pipe rim . A concrete support of the upper tank can constitute an ascent pipe in which a heating jacket is placed. The upper tank is covered by a solid floor of a shape of a dome or a cone. The upper tank can also be covered by a gasholder bell with a water seal. A mechanical agitator for scum breaking is installed on a middle part of the gasholder bell. A branch for gas supply with a control valve installed on it is led out from the upper part of bioreactor. A gas supplying branch from the side of the upper tank is connected by a gas stub with a gas holder and / or equalising gas pressure. A control vacuum valve is installed on the gas stub. The gas offtaking branch with the gas pump installed on it is connected with the upper part of bioreactor. The gas offtaking branch, from side of the upper tank is connected by a gas connecting stub with the gasholder and / or equalising gas pressure. An excess check-valve is installed on the gas connecting stub. The gas offtaking branch with the gas pump installed on it can also be connected with a gas pressure tank, out of which a gas connector with an impulse valve is led and joined with the upper tank and/or a gassing connector with a cut-off valve connected with the ascent pipe. From the gas pressure tank a gas pressure conduit with a safety valve is led taking-off a gas to the gasholder and / or equalising gas pressure. The upper tank can be made in a form of cylindrical tank of a vertical axis with a fasting flange. A liquid cut-off valve laying outside the upper tank is attached to the ascent pipe. From the ascent pipe, above the liquid cut-off valve, a blow-off pipe with a drain valve is led out.

A basic advantage of realisation according to the invention is , that yield per second of mixing during recirculation phase can be from a dozen or so to several hundred times larger than a yield of mechanical stirrer used in large anaerobic fermentation chambers with a biogas recovery. Additionally, the mixing according to the invention can occur without participation of the energy supplied from outside - using to this purpose an energy of gas being compressed in the bioreactor during fermentation of biomass present in it.

Short description of the drawings.

The subject of invention is presented in examples of performance in the drawings, in which Fig. 1 presents an apparatus diagramatically in vertical axial section, Fig. 2 - presents an apparatus in cross- section in A-A plane of the Fig. 1; Fig. 3 presents the apparatus similar to that presented in Fig.1, but with different equipment and the biomass control; Fig. 4- presents the apparatus in cross section in B-B plane of the Fig.3; Fig. 5 - presents upper and lower fragment of an apparatus modification in a vertical axial section with upper tank in a shape of vertically placed cylindrical tank; Fig. 6 - presents the apparatus in cross section in C-C plane of the lower fragment of the Fig. 5. Fig. 7 presents the apparatus in vertical axial section , the same as was shown in Fig. 5, but with differentiated equipment and the biomass control.

Principal use of the Invention.

The system according to the invention is equipped with an upper tank 1 , into which an ascent pipe 2 is mounted and out of which at least one recirculation pipe 3 is offtaken . The upper tank 1 is attached to a floor 4 of the bioreactor 5 in a monolytical performance as it was shown Fig. 1 and Fig. 3. or is installed separately on the floor 4 and fixed to it using a flange 6 , that is presented in Fig. 5 and Fig. 7. To the upper tank 1 a supplying branch 7 is led with a control valve 8 installed on it, but the second end of the supplying branch 7 of is connected with the upper part of the bioreactor 5 . The supplying branch 7 from the side of upper tank 1 is connected by a gas stub 9 with a gas holder and / or equalising the pressure. From the upper tank 1 an offtaking branch 10 can be installed with a gas pump 11 and introduced to the upper part of the bioreactor 5, that is shown in Fig. 5. The process of mixing according to the invention is carried out in two phases following one after the other ; in an ascent phase and in a recirculation phase. In the ascent phase the control valve 8 becomes closed , and the gas being formed during biomass fermentation an / or the gas from the upper tank 1 forced into the bioreactor 5 with a gas pump 11 through the offtaking branch 10) compresses in the upper part of the bioreactor 5 . This gas exerts a pressure on a surface of the biomass level lying below and displaces it from its common filling level 12 towards the bottom, till it achieves a minimal filling level 13 in bioreactor 5 . In this time, the biomass displaced from the bioreactor 5 flows from the bottom of bioreactor 5 through the ascent pipe 2 upwards into the upper tank 1 . When the biomass in the upper tank 1 riches the filling state 14 , or in the bioreactor 5 the minimal filling state 13 the control valve 8 gets open and the recirculation phase starts. The gas compressed earlier in the upper part of the bioreactor 5 goes to the upper tank 1 through the supplying branch 7 , and an excess of decompressed gas is directed through a gas stub 9 to the gasholder and/or pressure equaliser . In this phase of mixing , the biomass swelled earlier in the upper tank 1 flows through the recirculating pipeline 3 to the upper part of the bioreactor 5 , until in the upper tank 1 a lower biomass filling state 15 is reached. During the recirculation phase rather violent biomass mixing occurs in the upper part of the bioreactor 5, because large portion of biomass are ejected in a short time from the upper tank 1 to the upper layers of the biomass in bioreactor 5. It causes an intensive mixing of the scum layer formed on the biomass surface in the bioreactor 5 , an uniform distribution of the biomass in a whole volume of the bioreactor 5 and a proper its homogenisation. The recirculation pipelines 3 are equipped with a water seals H of height enclosed between the upper edge of the bottom inlet of the recirculation pipelines 3 , situated in the upper tank 1 or the upper edge of the opening of the lowest part of the recirculating pipe and the lower biomass filling state 15 in the upper tank 1. The upper endings of the recirculation pipelines are led to the upper part of the bioreactor 5 , and they are having at least one opening or a side stub 16 laying above the normal biomass filling level 12 of the bioreactor 5. The upper endings of the recirculation pipelines can have vertical stubs 17 of lower endings are placed in the bioreactor 5 below the minimal biomass filling level 13 and of diameters smaller than those of the recirculation pipelines 3. In an advantageous performance, shown in Fig. 1, the vertical stubs 17 are connected with an upper pipe rim 18 . From the upper pipe rim 18 side channels 19 are led off, situated on its circuit, that in the vertical section from the top they branch out in the same direction from an internal and an external surface of the upper pipe rim 18. In such a position of side stub pipes 16 and the vertical stub pipes 17 of the upper endings of the recirculation pipelines 3 in the upper part of the bioreactor 5, during the recirculation phase, the biomass is ejected from the upper tank 1 under its hydraulic pressure flows to the upper part of the bioreactor 5. through the side stub pipes 16 and is thrown on to the floating scum, while the remainder of the biomass flows downwards through the vertical stubs 17 to the upper pipe rim 18, from where it flows out through the side channels 19 causing the mixing of biomass in the bioreactor 5. The upper pipe rim 18 can be connected by a circulating branch 20 and attached on it a circulating pump 21 with a lower pipe rim 22, from which external and internal surface skew channels 23 are led out. These channels in the vertical section are pointed into the opposite direction that the side channels 19 of the upper pipe rim 18. After installing a heat exchanger 24 and/or heating elements 25 on the branch circulation 20 and advantageous circulation from top to bottom in the circulation pipe 20, owing to forced flow by the circulation pump 21, one gets a suitable heating system of the bioreactor 5. The side channels 19 led off slantwise from the upper pipe rim 18 and the skew channel 23 pointed in the opposite side to them cause additional swirls in the bioreactor 5, owing to that almost the same temperature level is kept in the whole volume of the bioreactor 5 . The upper endings of the recirculation pipelines 3 can also protrude as a whole above the normal biomass filling level 12 of the bioreactor 5 , and they are advantageously curved approximately under a right angle and pointed downwards under the acute angle to the level, that is shown in Fig. 3 and Fig. 4. In the Fig. 3 is shown the advantageous position of the lower endings of the recirculation pipe 3 that in the vertical section are tangent to the internal circuit of the upper tank 1 of the diameter larger than the diameter of the ascent pipe 2 and they lay near it and are directed in the same side. Such an arrangement of the lower endings of the recirculating pipe 3 causes numerous turbulence in the upperr tank 1 during the recirculation phase. The upper endings of the recirculation pipe 3 in the case of bioreactors of large capacity can be underslung to its floor 4 by usage of flexible connection 26. In the advantageous performance to the upper part of the ascent pipe 2 a feed pipe 27 is led, that can be connected by a stub suction pipe 28 directly or by means of the lower pipe rim 22 with the lower part of the bioreactor 5 , that is shown in Fig. 1 and Fig. 5. The suction stub pipe 28 is connected with an injector 29 installed on the feed pipe 27 . The supply of a fresh biomass to the lower part of the ascent pipe 2, during the rising phase causes accurate and turbulent mixing inside the ascent pipe 2 of the fresh biomass with an active and warm biomass being fed from the bioreactor 5 through the ascent pipe 2 to the upper tank 1. An earlier suction of biomass from the bioreactor 5 to the supply pipe 27 by means of the injector 29 is advantageous when one wants to heat and mix the biomass before supplying the ascent pipe 2 or directly to the upper tank 1 . An concrete pole can constitute the ascent pipe 2 , on which the upper tank 1 is built and inside it a heating jacket 30 is situated. In this case the ascent pipe 2 plays a role of assembling and transporting tower during a construction of the bioreactor 5. The upper tank 1 is usually covered over a solid roof 31 ^{of a} shape of a dome or a cone or by a gas -holder bell 32 with a water seal 33. On the gas - holder bell 32 can be installed a mechanical agitator 34 for scum breaking in the upper tank 1. On the ascent pipe 2 can be installed a liquid cut-off valve 35 In the case it is open, the biomass flows freely through the ascent pipe 2 upwards - in the course of rising phase. If during the rising phase the cut-off valve 35 is closed , the increase in pressure in the bioreactor 5 will occur. By its periodical closing and opening , one generates impulses of a short duration of increase in a flow velocity of biomass by the ascent pipe 2 to the upper tank 1 and in the case of exceeding a critical pressure in the bioreactor 5 the return water seal H on the recirculating pipes is broken. The water seal H protects against a penetration of the biomass from the upper part of the bioreactor 5 to the upper tank 1 , but in this case it also plays the role of protection against an excessive increase of pressure in the bioreactor 5. The achievement of a critical gas pressure in the upper part of the bioreactor 5 after an interruption of the water seal H can serve purposely for mixing of biomass in the upper tank 1 , owing to gas bubbling from the lower endings of recirculation pipe 3. From the ascent pipe 2, above the liquid cut-off valve 35 a blow-off pipe 22 can be drained off with installed on it a blow-off valve 37. When the liquid cut-off valve 35 is open and after opening the blow-off valve 37 a deposit from the bottom of the bioreactor 2 is drained off through the blow-off pipe 36 or , after closing the liquid cut -off valve 35 , the scum occurring in the upper tank 1 is removed through the same pipe. In the advantageous performance, the upper ending of the ascent pipe 2 protrudes above a bottom 38 of the upper tank 1, The upper tank bottom the most often is built of the shape of truncate cone with a vertex directed downwards. As it was shown in Fig.1, the upper ending of the ascent pipe 2 can be ended by an open hopper 39 widening upwards, which the upper edge is placed on the height equal to or lower than the higher level of filling 14 by biomass of the upper tank 1. From the side walls of the open hopper 22 blowdown connections 40 are led out that in a vertical section are arranged in a similar manner as the recirculation pipe 2. The blowdown stubs 40 of the open hopper 39 of the ascent pipe 2 serve to the uniform distribution of the biomass in the upper tank 1 handed through the ascent pipe 2 from the lower part of bioreactor 5. During the recirculation phase a part of biomass from the upper tank 1 returns through the ascent pipe 2 into the lower part of the bioreactor 5 and in this manner breaking and pumping downwards a scum present in the upper tank 1 occur. The upper ending of the ascent pipe 2 can also be placed above the higher level of the biomass filling state 14 in the upper tank 1 , that was shown in Fig. 7. During rising phase the biomass displaced from the bioreactor 5 reaches the upper tank 1 through the ascent pipe 2 and overflows through the upper ending of this pipe causing the mixing of biomass layers in the upper tank 1. In the case, when more intensive biomass mixing is necessary in the upper tankl, the upper ending of the ascent pipe 2 is equipped with a conical nozzle 41, above which a mixing pipe is placed. The upper widening end of mixing pipe is placed between the level of lower filling state 15 , and the level of higher biomass filling state 14 in the upper tank 1, that is shown in Fig.3. During the rising phase the biomass being moved through the ascent pipe 2 to the upper tank 1, owing to its kinetic energy sucks in a part of biomass from a bottom 38 of the upper tank 1, and these two streams of biomass are mixing together in a mixing pipe 42 and flow above the upper widened ending of this pipe. This causes pretty intensive circulation of biomass in the upper tank 2. The installation according to the invention can be built outside the place of a construction of bioreactor 5 and next it can be transported to the place of construction and assembled on the floor 4 of the bioreactor 2, that is shown in Fig. 5 and Fig. 7. Such a realisation accelerates the process of the bioreactor 5 construction and putting it into operation. During its repairing such a installation can be temporarily or for ever changed for a new one as well as for a repaired installation according to the invention. In the apparatus according to the invention presented in Fig. 5 and Fig. 7 a negative pressure control valve 43 was installed on a gas stub pipe 9. It enables the operation of the installation according to the invention also in a different manner. In this means a rising phase starts at the same moment as it was described earlier, but the negative pressure control valve 43 placed on the gas stub 11 becomes closed and the gas is led out from the upper tank 1 by the drain -off branch 10 ky the usage of a gas pump 11 assembled on it . At the same time, by simultaneous closing of the control valve 8 on the supplying branch 7 , in the upper tank 1 a negative pressure is formed, owing to that the biomass is sucked from the lower part of the bioreactor 5 through the lower part of the ascent pipe 2 to the upper tank 1, In this realisation the bioreactor 5 can be equipped with a separate connection for a gas , connected with a gas holder and/or equaliser of the gas pressure. In recirculation phase, after the achievement by the biomass in the upper tank 1 the level of higher filling state 14 or by the achievement by the biomass in the bioreactor 5 the minimal filling level 13 the control valve 8 opens. Consequently the pressure in the upper tank 1 rises and the biomass from the upper tank 1 is led out to the bioreactor 5 under an influence of its hydrostatic pressure and increased gas pressure in the upper tank 1 , because of that the state of biomass filling in the upper tank 1 falls, and in the bioreactor 5 it increases, and again that the biomass once more reaches the level of lower filling state 15 in the upper tank 1 . The excess of gas from the upper tank 1 is removed by an opening of negative pressure control valve 43 on the gas stub pipe 9, or through the junction gas pipe 44 installed on the drained -off branch 10 together with the return excessive valve 45 , to the gas holder and / or equaliser the gas pressure. In the course of the rising phase the gas pumped with the gas pump 11 from the upper tank 1 can be compressed in the pressure gas holder 46 connected the upper tank 1 through the drained branch 10 .During the recirculation phase, whereas the compressed gas from the gas pressure vessel 46 is led by the usage of a gas connector 47 - after opening of an impulse valve 48 installed on it and / or by means of a gassing connector 49 - after opening of a cut-off -valve 50 installed on it. The excess of gas can be removed from the upper tank 1, through a gas pressure conduit 51 with a safety valve 52 installing in the upper part of the pressure vessel 46 and through this connection gas can flow to the gas holder and / or equaliser the gas pressure. In the case of an accidental closing or choking of the ascent pipe 2 during rising phase, after overcoming the critical vacuum pressure in the upper tank 1, the return water seal H becomes open and as a result of this the gas from the upper part of the bioreactor 5 goes to the upper tank 1 through the bottom ends of the recirculating pipe 3 , which can be objective solution of biomass mixing in the upper tank 1. In the modification of the solution according to the invention described above shown in Fig. 5 and Fig. 7, the upper tank 1 is made as a cylindrical vessel situated vertically in the bioreactor axis with the fasting flange 6.

Industrial application.

The apparatus designed in examples presented in the figures is adapted in particular for anaerobic fermentation with gaining the biogas from the slurries of organic matter such as sewage sediments, liquid manure, slaughter wastes and others. The installation according to the invention can be adapted to sewage treatment containing dissolved organic compounds by adding to them a loose artificial filling and/or filling the bioreactor 5 with an artificial bed.

Claims

PATENT CLAIMS

1. The method of mixing of fluid biomass in a bioreactor, especially in the presence of mezophyllic microorganisms and / or thermophyllic with obtaining the methane gas simultaneously, in which the biomass is moved from the bottom of the bioreactor by means of the ascent pipe , is significant on account of the mixing occurring in two phases, one after the other; in a rising phase during which a biomass under gas pressure being increased in the upper part of the bioreactor 5 and / or under gas pressure being decreased in the upper tank (1) is transported through the bottom end of the ascent 2 into the upper tank (1), where the process of biomass swelling occurs - and in a recirculating phase during which at least a majority of the biomass swelled before at the upper tank (1) is put into the upper layers of biomass being in bioreactor (5) under an influence of hydrostatic pressure or both, hydrostatic pressure and increased gas pressure at the upper tank (1), · The duration time of the recirculation phase is shorter than the rising phase.

2. The method according to the claim 1, characterized , that the rising phase begins after a gas-tight closing of bioreactor [ 5 ) , and the recirculation phase starts from the moment of gas drainage from the bioreactor (5).

3. The method according to the claim 2, characterized ,that the bioreactor ( 5 ) becomes closed gas - tightly at the moment of achievement by the biomass at as a result of its own gas production and / or gas supplied into the bioreactor (5) in an artificial manner, the biomass is displaced by gas to the upper tank (1) , causing an increase in the biomass filling state at the upper tank (1), while gas the from the bioreactor (5) is drained off when the biomass reaches a higher level of filling (14) at the upper tank (1) as a result of that the gas pressure at the bioreactor (5) decreases, and in the place of the gas drained off from the bioreactor ( 5) the biomass from the upper tank (1) is transported under its hydrostatic pressure , resulting the diminishing of the biomass filling at the upper tank (1) , and increasing the bioreactor (5) filling, and again the biomass reaches the lower filling state (15) at the upper tank (1).

4. The method according to the claim 3, characterized, that at the moment when the biomass in the upper tank (1) reaches the higher filling state (14) or when the biomass reaches the minimal level of filling 22 at the bioreactor (5) , the gas from the bioreactor (5) gas from the bioreactor (5) flows to the upper tank (1) or to the gas holder and / or equalizing gas pressure.

5. The method according to the claim 1, characterized, that the rising phase starts from the moment of gas drainage from the bioreactor (5) , and the recirculation phase begins from the moment of supplying gas to the upper tank (1).

6. The method according to the claim 5, characterized, that the gas drainage from the upper tank (1) is performed when the biomass achieves the lower filling level (15) at the upper tank (1) , as a result of that , in the upper tank (1) a negative pressure arises, that causes the biomass suction into it from the bioreactor ( 5 ) , and owing to that, the state in the biomass filling of the upper tank (1) increases, while the gas is directed into the upper tank (1) at the moment when the higher level of biomass filling (14) is reached in the upper tank (1) or if the minimal level of biomass filling (13) is reached in the bioreactor (5). as a result of that, the pressure in the upper tank (1) increases and the biomass is moved from the upper tank (1) to the bioreactor (5) under its hydrostatic pressure or under the influence of its hydrostatic pressure and enhanced gas pressure at the upper tank (1), therefore the state of filling in the upper tank (1) falls and in the bioreactor [5] increases, and after that again the biomass reaches the lower filling state (15) at the upper tank (1) .

7. The method according to the claim 5, characterized , that during the rising phase , the gas from the upper tank [ 1 ] is being drained off and introduced into the bioreactor [ 5), and during the recirculation phase, the gas being supplied to the upper tank (1 ) is turned back from the bioreactor (5) and / or gas holder and / or equalizing gas pressure.

8. The method according to the claim 5, characterized, that during the rising phase, the gas drained off from the upper tank (1) is compressed in a pressure tank (46) , and in recirculating phase the compressed gas from the pressure tank (46) is supplied into the bioreactor and / or to the ascent pipe (2).

9. The method according to the claim 1,

characterized, that the fresh ration of the biomass or the fresh ration of the biomass mixed before with the biomass from the bioreactor (5) is supplied to the bottom of the ascent pipe (2).

10. The method according to the claim 1, characterized, that the fresh portion of the biomass or fresh portion of the biomass mixed before with the biomass from the bioreactor ( 5) is supplied to the upper tank (1).

11. The apparatus for mixing of fluid biomass in the bioreactor, especially in the presence of mezophyllic and / or thermophyllic microorganisms with obtaining of the methane gas simultaneously, having an ascent pipe, which the lower ending is placed at the lower part of the bioreactor - above the middle part of its bottom of a funnel shape, characterized, that the upper end of the ascent pipe ( 2 ) is placed in the upper tank (1), from which at least one recirculation pipe ( 3) closed in return manner is led out for returning the biomass from the upper tank ( 1) to the upper part of the bioreactor

(5) . The upper tank (1) is placed inside and / or above the bioreactor (5) , and is equipped with the supplying branch (7) and / or the offtaking branch (10) for gas.

12. The apparatus according to the claim 11, characterized, that the upper end of the ascent pipe

(2) protrudes above the bottom [38 ]of the upper tank The bottom of the upper tank is realised advantageously in the shape of truncated cone.

13. The apparatus according to the claim 12, distinctive from others, that the upper end of the ascent pipe (2 ) is ended with the open hopper ( 39) broadening upwards, which the upper edge is placed on the height equal to lower than he higher filling state (14) of the upper tank (1) by the biomass.

14. The apparatus according to the claim 13, distinctive from others, that from the open side wall of the open hopper (22) the blow down stub ( 40) is led out

15. The apparatus according to the claim 12, distinctive from others, that the upper end of the ascent pipe (2 ) protrudes over the higher filling state (14) by the biomass in the upper tank (1).

16. The apparatus according to the claim 12, distinctive from others, that the upper end of the ascent pipe (2 ) is ended by the nozzle (41), above which the mixing pipe ( 42 ) is placed coaxially, which the upper broadened end is placed in the upper tank (1) between the lower filling state (15) and the higher filling state ( 14) by the biomass.

17. The apparatus according to the claim 11, characterized, that at least of the recirculating pipe

(3) has the return water seal [H] , the inlet of the recirculating pipe (3) is placed in the lower part of the upper tank (1) below the minimal filling level (13) by the biomass of the bioreactor (5) or above this level with additional curve of the recirculating pipe ( 3) towards the bottom, below the minimal filling level (13) by the biomass of the bioreactor (5) , and the highest outlet of the recirculating pipe (3) is placed in the upper part of the bioreactor (5] above the normal filling level (12) by the biomass in the bioreactor (5).

18. The apparatus according to the claim 17, characterized, that the height of the return water seal (H) is larger than the distance between the lowest edge or the hole of the ascent pipe [ 2) placed in the upper tank (1); and the normal position of the normal filling level (12) by the biomass in the bioreactor (5) , above which this edge or hole is situated.

19. The apparatus according to the claim 17, characterized, that at least one from the outlets of the recirculating pipe (3 ) is immersed in the bioreactor (5 ) below the minimal filling level (13) by biomass and by the vertical stub (17) is connected with at least one outlet of this pipe placed above the normal biomass filling level (12) , the diameter of this stub is smaller than the diameter of the recirculation pipe ( 2 ) .

20. The apparatus according to the claim 19, characterized, that the outlets of the recirculation pipe( 3) Placed above the normal biomass filling level

(12) in the bioreactor (5) are ended with side stubs (16) ,, which ends are placed above the normal biomass filling level (12) in the bioreactor (5).

21. The apparatus according to the claim 19, distinctive from others, that the lower end of the vertical stub (17) is connected with the upper pipe rim (18), having the side channels 19) placed on its circumference.

22. The apparatus according to the claim 21, characterized, that the side channels (19) of the upper pipe rim [ 18) in the vertical section from the top, branch out in the same direction from the internal as well as external surface of the upper pipe rim (18) under the acute angle in relation to these surfaces, in order to cause an rotatory motion of the biomass in the bioreactor (5) round its axis of symmetry.

23. The apparatus according to the claim 21, characterized, that the upper pipe rim (18) is connected with the circulating branch [ 20 ) with the circulating pump (21) attached on it with the lower pipe rim [ 22) , out of which external and internal surface are led out the skew channels (23), that in the vertical section are directed into the opposite direction in relation to the side channels (19) of the upper rim (18).

24. The apparatus according to the claim 23, characterized, that the heat exchanger (24) and / or the heating elements (25) are installed on the circulating branch (20).

25. The apparatus according to the claim 11, characterized, that bottom ends of the recirculation pipes [ 3) i the vertical section are tangent to the internal circle of the upper tank [ 1) ^of the diameter larger than the diameter of the ascent pipe (2) and they lay nearby it, while the upper endings of the recirculating pipes (3) are bent approximately under the right angle and turned advantageously under the acute angle to the level.

26. The apparatus according to the claim 25, characterized, that the upper endings of the recirculating pipes [ 3) are underslung to the floor [4 ] of the bioreactor ( 5 ] by usage of the flexible connectors (26) .

27. The apparatus according to the claim 11, distinctive from others, that the supply pipe (27) is led to the lower part of the ascent pipe (2 ) .

28. The apparatus according to the claim 27, characterized, that the injector (29) sucking the biomass from the bioreactor [ 5 ) through the suction stub pipe (28) is installed on the supplying pipe (27).

29. The apparatus according to the claim 28, distinctive from others, that suction stub pipe (28) is connected with the lower pipe rim ( 22 ) .

30. The apparatus according to the claim 11, characterized, that the concrete support of the upper tank (1) constitutes the ascent pipe (2 ), in which the heating jacket (30) is placed.

31. The apparatus according to claim 11, characterized , that the upper tank (1) is covered by the solid floor (31) ^{of a} shape of a dome or a cone.

32. The apparatus according to the claim 11,

characterized, that the upper tank (1) is covered by the gasholder bell (32) with the water seal (33 ) .

33. The apparatus according to the claim 32, characterized, that the mechanical agitator (34) fore scum breaking in the upper tank (1) is installed on the middle part of the gas holder (32).

34. The apparatus according to the claim 11, characterized , that the gas supplying branch (7) with the control valve (8) installed on it is led out from the upper part of the bioreactor (5) .

35. The apparatus according to the claim 34, characterized, that the gas supplying branch (7) from the side of the upper tank (1) is connected by the gas stub (9) with the gas holder and / or equalising gas pressure.

36. The apparatus according the claim 35, characterized, that the control vacuum valve [ 43 ) is installed on the gas stub ( 9 ) .

37. The apparatus according to the claim 11, characterized, that the gas offtaking branch [ 10) with the gas pump (11) installed on it is connected with the upper part of the bioreactor ( 5) .

38. The apparatus according to the claim 37, characterized, that the gas offtaking branch (10) , from side of the upper tank (1) is connected by the

gas connecting stub (44 ) with the gas holder and / or equalising gas pressure.

39. The apparatus according to the claim 38, characterized, that the excess check-valve ( 45 ) is installed on the gas connecting stub (44).

40. The apparatus according to the claim 11, characterized, that the gas offtaking branch (10) with the gas pump (11) installed on it is connected the gas pressure tank (46), out of which the gas connector (47) with the impulse valve (48) is led and joined with the upper tank (1) and / or the gassing connector (49) with the cut-off valve (50) connected with the ascent pipe (2).

41. The apparatus according to the claim 40, characterized, that from the pressure tank (46), the gas pressure conduit (51) with the safety valve (52) is led, taking-off the gas to the gas-holder and / or equalising gas pressure.

42. The apparatus according to the claim 11, characterized, that the upper tank (1) is made in a form of cylindrical tank of a vertical axis with the fasting flange (6).

43. The apparatus according to the claim, characterized, that the liquid cut-off valve ( 35) laying outside the upper tank (1) is attached to the ascent pipe (2 ).

44. The apparatus according to the claim, characterized, that from the ascent pipe (2) , above the liquid cut-off valve (35), the blow-off pipe ( 36) with the drain valve (37) is led out.