DE102011118204A1 - Mixing device for mixing and fermenting e.g. liquid manure, in container in biogas plant, has pivoting levers associated with hinge elements for height adjustment of agitating device, and supply line arranged in container wall - Google Patents

Abstract

The device has a submersible agitator (1) immersed and operated in the interior of a container. Pivoting levers (4, 8) are associated with hinge elements (6b, 6c) for height adjustment of the agitating device. A bearing bracket is arranged in the interior of the container for receiving the pivoting lever, and a supply line is arranged in a container wall (3) in a gas-and liquid-tight manner, where the supply line is provided in a protective tube that is connected with the pivoting levers by a holder.

Description

Technical area

The invention relates to a mixing device for substrates or liquids in containers on biogas plants and the like with an immersion agitator arranged on one or more articulated arms.

Under Tauchrührwerk or sometimes referred to in various publications as submersible agitator is hereinafter understood a operated under the liquid level unit consisting essentially of a housed in a liquid-tight housing drive motor with and without gear and a flow-generating part driven there, usually a mixing propeller.

The mixing device allows a height adjustment of the submersible mixer and a direction adjustment exclusively via articulated elements connected to pivot arms and hinge elements.

The torque required for adjustment preferably results from the thrust of the propeller and the effective distance of its thrust vector to the horizontal and vertical axis.

With a control system, mixing operations can be input in advance, which are event-related or processed by the submersible mixer according to the instructions at a preselected time.

Containers on biogas plants are subdivided according to their function into pre-pits, mixing tanks, fermenters, secondary fermenters and repositories.

Fermenters become with solids, which are today predominantly renewable raw materials (Nawaros) such as corn, grass, etc. however z. As well as solid manure on solid inputs fed directly, the liquid phase, such as liquid manure is collected in pre-wells and fed to the fermenter via pumps.

Sometimes the liquid and the solid portion are already spent before the fermenter in Anmaischbehälter, there homogenized and fed liquid to the fermenter.

Biomass is fermented in fermenters and secondary fermenters of biogas plants. The resulting from the anaerobic degradation of organic matter in the fermenter biogas is used directly on the system in cogeneration plants for the production of electrical energy or fed into the gas network. Fermenter and Nachfermenter are gas-tight and are operated with gas pressures of a few millibars. Often, containers with film roofs are used, but there are also containers with concrete ceilings.

A homogenization of the substrate is indispensable for an undisturbed process flow and for an even gas production. The substrate then passes in the overflow method according to the principle of communicating tubes or by pumping from the fermenter on the secondary fermenter into the repository.

In the mostly gas-tight repository, the fermented substrate is stored from the fermenters and the resulting residual gas is also recycled. The substrate is occasionally dumped on fields or otherwise utilized.

Changing fill levels are to be expected due to the function of pre-pits, mixing tanks and repositories. If the storage space in the repository is too small, changing fill levels are also conceivable for secondary fermenters. A height adjustment of the agitator is essential in these cases.

Due to the density difference of the substances to be mixed in the containers, especially in Nawaros with a rapid segregation and with the risk of sudden floating surface formation can be expected.

However, the above-described relationships require complete mixing, even individual dead zones would increasingly accumulate with solids and eventually in the worst case, the entire substrate surface with a gas production inhibiting floating cover. In order to avoid such dead zones, more than one agitator is usually provided, these are then to be positioned at different heights and possibly also with predetermined beam directions. In order to reduce capital expenditure, the number of agitators is often minimized and a time-consuming manual adjustment is required.

State of the art

State of the art adjusting devices are after DE 20 2009 001 118 . DE 20 2008 002 576 or DE 10 2007 062 563 , in which the submersible mixer with a sliding carriage on a vertically installed form tube guided via a cable in height and by pivoting the guide tube about the vertical axis are made adjustable by a horizontal angle.

The energy is supplied via the electric cable, either on the wire rope or over a separate guide rod is guided in loops. Most inevitable langfaserige fabric parts hang in the course of time to this length adjustment by adjusting the height necessary cable loops and lead to fluttering of the cable in the flow similar to a hung on a rope to dry laundry in the wind. This permanent mechanical load and the development of tangling due to clogging always entail the danger of cable breaks.

Although the use of more or less elastic protective tubes for the power supply line reduce the risk of cable breaks something, but can never completely prevent interference. If, despite all efforts, floating ceilings are formed, it is to be expected that the protective hose will bend off and thus completely eliminate the protective effect for the cable.

Also around the substantially vertically oriented mold tube hang the mentioned long-fiber material parts and beyond is to be expected with caking in the transition region gas substrate. The immersion agitator is guided along a sliding carriage along the forming tube, which must be designed with little play to prevent inadmissible vibrations during the operation of the agitator. The caking and also the long-fiber fabric parts often interfere with the height adjustment and lead repeatedly to business interruptions.

The wire rope for the height adjustment is also susceptible to interference. Inevitable vibrations due to the rotating mixing propeller force the wire rope so much that only a frequent replacement can prevent rope breakage.

In addition, in gas-tight containers, both the wire rope and the adjustment must be performed consuming and maintenance-intensive through the container wall to the outside.

An improvement in terms of manual effort are adjusting devices, in which the height adjustment is motorized. In the DE 10 2007 009 451 Such a motor-height-adjustable submersible mixer with an automatic height adjustment to the level is described. The immersion agitator with the sliding carriage is guided on a forming tube and adjusted via a cable. To detect a necessary pivoting movement around the entire container area, would have to be carried out manually.

The aforementioned disadvantages with the sliding carriage on the forming tube, the wire rope and the cable guide also apply here, these disadvantages are compounded by the fact that in automatic operation often the necessary control and the immediate correction, as given in manual operation, is missing.

An improved execution in terms of manual effort is also in the DE 100 09 958 disclosed. About a lifting device to be lowered on a guide device and to be lifted from the container flow aggregate for containers. The flow aggregate or submersible agitator is still moved up and down on a guide device so as to be prone to malfunction, manual adjustment of the height is also necessary since the adjustment of the jet direction can by no means replace height positioning. The problem with the cable, the wire rope and the tendency to block slide guide is also not solved.

An improvement in terms of cable management provides the guiding device for a submersible mixer DE 20 2005 017 638 , The submersible mixer is attached to a rail which is mounted in a pivot bearing in the immediate vicinity of or in the wall of a container. This allows a pivoting in at least one spatial direction. By supplying the drive energy within the rail are in the environment no lines in the substrate. A cable device is also no longer necessary. The possible pivoting movement of the submersible mixer is made from the outside of the container.

However, the gas-tight implementation of the pivotable rail through the container wall is complex and is solved in the present case with a rubber cuff, which should accommodate the pivotal movement of the rail. The wall bushing also limits the pivoting angle at the same time both about a vertical and about a horizontal axis and thus requires a very long rail, at the end of the submersible mixer is fixed so that both the upper and in the lower area can be stirred and the stirring jet not too deviates strongly from the horizontal. The reaction forces thus lead to significant, the overall design and the container wall stressful moments. Accordingly, the area that can be coated with the propeller jet, greatly restricted.

In larger fermenters also several submersible mixers are used stationary according to the prior art, a variant is in the DE 10 2010 014 239 disclosed. Two submersible agitators are used so that they should work in correspondence with each other. A fixed installation of the supply lines is not possible even with stationary installation, since the agitators must be lifted out in case of service.

The Rührstrahlrichtung is determined once permanently determined, so dead zones are in operation in the frequently encountered changing input materials even with several corresponding submersible mixers unavoidable, moreover, the investment costs are relatively high.

Object of the invention

• • eine zur Blockierung neigende Schlittenführung
• • ein freihängendes, flatterndes und langfaserige Stoffteile aufsammelndes Kabel
• • ein bruchgefährdetes Drahtseil auskommt. Darüber hinaus soll die erfindungsgemäße Mischvorrichtung
• • einen geringen Abstand zum Lagerpunkt zur Reduzierung entstehender Kräfte und Momente aufweisen
• • eine zeit- bzw. ereignisgesteuerte Automatisierung des Mischvorgangs mit vorwählbaren Positionen sowohl in der Höhe als auch im Winkel des zur Mischpropellerachse koaxialen Rührstrahls ermöglichen und damit das Entstehen von Totzonen zuverlässig und ahne manuellen Aufwand verhindern.
• • eine kostengünstige Serienfertigung ermöglichen

The object of the invention is therefore to provide a mixing device with comparatively low capital expenditure, which without

• • a sledge guide tending to lock
• • a free-hanging, flapping and long-fiber fabric pieces collecting cable
• • a breakage-prone wire rope gets by. In addition, the mixing device according to the invention
• • have a small distance to the bearing point to reduce forces and moments
• • enable time- or event-controlled automation of the mixing process with pre-selectable positions in both the height and the angle of the mixing jet coaxial to the mixing propeller axis and thus reliably prevent the formation of dead zones reliably and without manual effort.
• • enable cost-effective mass production

Description of the invention

The object of the invention is achieved in that the height adjustment takes place only on attached to joint elements arms and the supply lines are fixed in the pivot arms and thus come into contact neither with the gas nor with the substrate. One or more hinge elements with articulated arms attached thereto allow for height adjustment and almost any choice of beam direction, thereby avoiding dead zones and effectively breaking up resulting floats.

The submersible agitator is advantageously mounted on the last pivoting arm so that the mixing jet coaxial with the mixing propeller axis produces an effective distance of the reaction force of the flow impulse to the respective pivot axis and the resulting torque can be used for adjustment.

In a preferred further embodiment of the invention releasable blocking elements are housed in the joint structures, the adjacent pivot lever or the bearing bracket rigidly connect to the first hinge lever together. Thus, a predetermined position of the Tauchrührwerks in height and the beam direction of the mixing propeller is determined.

The mixing device according to the invention can be used in largely unchanged design both in containers with concrete ceiling or gas hood and for mash tank, pre-wells, fermenter, Nachfermenter and repository for use and thus enables cost-effective mass production.

LIST OF REFERENCE NUMBERS

1

submersible agitator

2

gas hood

3

container wall

4

first swivel arm

5

bearing bracket

6a

Joint element 1

6b

Joint element 2

6c

Joint element 3

7a

Blocking element 1

7b

Blocking element 2

7c

Blocking element 3

8th

second swivel arm

9

Liquid or substrate mirror

10

Swing angle around axis A

11

Swing angle around axis B

12

Swing angle around axis C

13

Container bottom or container bottom

14

Horizontal position of the first swivel arm

16

floor console

17

supply line

18

Wall penetration of the supply line

A

Axle of the first joint element

B

Axle of the second joint element

C

Axle of the third joint element

a

Distance of the axis A to the container wall

b

Distance between the first and second joint element

c

Effective distance of the flow pulse for torque generation about the axis B

d

Effective distance of the flow pulse for torque generation about the axis C.

In the following drawings, the invention is explained in more detail, showing:

1 a schematic sectional view of a first embodiment of the mixing device in the side view with the top view 2

3 to 8th Further arrangements, each with the corresponding plan view to illustrate the great possibility of variation of the axial positions and pivot lever in the invention

10 schematically the leadership of the supply lines

11 and 12 a schematic sectional view in the side view and plan view of another embodiment

1 and 2 show schematically a biogas fermenter with a container ( 3 ), a gas hood ( 2 ) and a bearing bracket mounted on the inside of the container ( 5 ) and a first joint element ( 6a ) with an approximately horizontal, approximately parallel to the container wall axis A. In this joint element is a blocking element ( 7a ), which is a required locking of the subsequent first pivot arm ( 4 ). A second joint element ( 6b ) is also mounted at the other end of the first pivot arm, which allows a pivoting of the adjoining articulated arm about a second axis B, which is approximately parallel to the first axis. In this joint element is also another blocking element ( 7b ) for a required locking of the first to the second pivot arm ( 8th ) housed. A third joint element ( 6c ) is mounted at the end of the second arm and allows pivoting of the third pivot arm about a third axis C which coincides with the longitudinal axis of the second arm and thus extends orthogonal to the second axis. Also in this joint element is a blocking element ( 7c ), so that the second and the third pivot arm can be blocked to each other. At the end of the third arm is the immersion agitator ( 1 ), which can thus be adjusted via the joint structures in all three spatial axes. The length of the arms is selected so that the outer circle of the mixing propeller of the submersible agitator in a horizontal jet position both approximately to the tank bottom ( 13 ) as well as the possible filling height of the container ( 9 ) enough.

The adjusting moments, for example, about the first axis A in the pivoting movement ( 10 ), which is considered in the extended position of the first and second pivot arm for the sake of simplicity, results from the product of the effective distance (b + c) and the reaction force of the flow impulse of the stirring jet. The maximum possible moment is achieved when the thrust direction acts perpendicular to the axis A, the immersion agitator before according to the pivoting movement ( 12 ) Was thus pivoted about the axis C before.

3 and 4 clarify the possibilities according to the invention with different arrangement of the joint axes. The axis B of the second joint element ( 6b ) coincides with the longitudinal axis of the first pivot arm and the second pivot arm moves on a plane orthogonal thereto. As a result, any angle of the beam axis can be adjusted to the horizontal.

5 and 6 show a further preferred variant. To reduce the investment costs here are only two joint axes ( 6a and 6b ) intended. The preferred circular flow is achievable at any altitude clockwise and counterclockwise. The adjusting moment about the axis A is calculated from the effective distance to the mixing propeller axis. The maximum possible adjustment also acts here with previous pivoting of the submersible mixer in the swivel range ( 12 ) about the axis B until the thrust direction acts perpendicular to the axis A.

7 and 8th also show a two-axis mixing device according to the invention, wherein the first axis A in the bearing console ( 5 ) is oriented approximately vertically and the second axis B is arranged orthogonal thereto. Thus, in this case also in the highest and in the lowest position a circular flow in both directions can be achieved, intermediate positions allow an inclination of the stirring jet, as it might be useful for use in the vicinity of solid entries.

9 shows the guide according to the invention of the supply lines using the example of the previous embodiment according to 3 and 4 , The supply line ( 17 ) becomes liquid-tight through the container wall ( 3 . 18 ) protected in the storage console ( 5 ) in the first joint element ( 6a ) and then inside the first pivot lever ( 4 ), the second joint element ( 6b ) and the second pivot arm ( 8th ) through the interior of the third joint element ( 6c ) and the second pivot arm ( 8th ) to the immersion agitator ( 1 ) guided.

10 and 11 show in a further embodiment of the invention, the attachment of the console at a distance from the container wall ( 3 ) on the tank bottom. The cultivation of all variations shown above is possible according to the invention.

The supply line would advantageously in this case from the console on the tank bottom along the wall and then gas-tight therethrough.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 202009001118 [0015]
• DE 202008002576 [0015]
• DE 102007062563 [0015]
• DE 102007009451 [0021]
• DE 10009958 [0023]
• DE 202005017638 [0024]
• DE 102010014239 [0026]

Claims (14)

Mixing device for containers on biogas plants and the like, consisting of a submersible, which is operated submerged inside the container, characterized in that the height adjustment and the setting of the Rührstrahlrichtung exclusively with at least two or more joint elements connected pivoting levers and the bearing bracket for recording the first pivot lever is also disposed in the container interior and thus only the supply line gas and liquid-tight must be performed by the container wall. Mixing device for fermenters and the like, consisting of a container with a vorzugswese gas-tight roof, characterized in that on the inside of the container wall, a console is mounted with a first hinge construction with subsequent pivot lever, which can follow several joint structures and pivot lever and the last pivot lever Immersion agitator is mounted, the agitating jet can be adjusted in effective height and orientation via an adjustment of the joint elements to the requirements. Mixing device according to claim 1, characterized in that in the pivoting levers and in the joint elements interconnected, liquid and gas-tight cavities are arranged, which can receive the supply lines to the immersion agitator protected against substrate and gas contact. Mixing device according to the preceding claims, characterized in that the supply lines are guided in protective sleeves connected to the pivoting levers, for example via holders, which are made elastic in the region of the joint structures for compensating the change in angle between the connected elements. Mixing device according to one or more of the preceding industrial property rights, characterized in that the submersible agitator is mounted with the propeller axis at the end of the last articulated lever, which at each axis at least in an adjustable pivot position of the submersible agitator is an effective distance, which are effective on the flow impulse torque leaves that can be used to pivot the agitator. Mixing device according to one or more of the preceding patent rights, characterized in that the first hinge construction is attached to a bracket on the inside of the fermenter wall or on a console connected to the container base. Mixing device according to the preceding claims, characterized in that the oil chambers are connected in the submersible agitator, for example, for lubrication of the mechanical seal or the transmission via supply lines with mounted outside the substrate container oil reservoirs, which allow control and oil change without lifting the Tauchrührwerks. Mixing device according to one or more of the preceding claims, characterized in that a control unit is equipped with programming, memory and computing elements that detects the signals of the housed in the hinge elements rotary encoder and calculates the altitude and the beam direction of the mixing propeller and optionally in a display outputs. Mixing device according to claim 8 and the preceding claims, characterized in that the mixing operations with height position and beam direction are preprogrammed with the control unit and stored in the memory, the processing of which can be time-controlled and event-controlled. Mixing device according to claim 8, characterized in that the adjustment of the articulated lever by the momentum generated by the Rührstrahl pulse and its effective distance to the associated axis of the joint element torque after release of the blocking device between adjacent articulated levers or the first articulated lever and the bearing bracket and by subsequent locking of the Lever positions via the blocking device of the hinge elements in the predetermined by the computer of the control unit for each joint position. Mixing device according to one or more of the preceding claims, characterized in that the blocking means of the joint elements is designed as a toothed or disc clutch, the hydraulically, pneumatically or electrically releasable otherwise caused by spring stiff connection between two adjacent pivot arms or the first pivot arm with the bearing bracket forms. Mixing device according to claims 1 to 7, characterized in that adjusting mechanisms are incorporated in the joint structures, which take over the angular adjustment of the pivot lever. Mixing device according to one or more of the preceding claims, characterized in that in containers with gas hood in the upper wall portion a liquid and gas-tight closable maintenance opening is arranged, the after lowering the tank level allows maintenance of the submersible mixer through the open service door. Mixing device according to the preceding claims, characterized in that the liquid- and gas-purged structural parts of the adjusting elements are made of stainless steel.

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