WO2009062693A2 - Eccentric stirrer - Google Patents

Abstract

The invention relates to a mashing vessel which comprises: a housing with a centre axis, wherein the housing has a bottom part and a stirring mechanism with at least one stirring blade. In order to obtain an improved mash-stirring action, the stirring mechanism is arranged eccentrically in the housing, wherein the stirring mechanism axis and the centre axis are spaced apart in the housing.

Description

 Eccentric stirrer

The invention relates to a mash vessel 1 according to the preamble of claim 1.

Mashing is an important process in wort production. The task of the mashing process lies in the best possible mixing of the meal and the mashing water. The desired ingredients present in the malt should be optimally dissolved in this process.

The known mash vessels, such as e.g. Mashed or mash tuns usually have a conical bottom that tapers downwards. For better mixing a stirrer is provided. Often the floor is also designed as a heating surface.

In Fig. 7, a mash vessel without extractor is shown schematically, as is known from the prior art. The mash supply and removal or cleaning solution removal is located in the middle of the vessel, also called outlet bowl. The conventional floor 9 has an elaborate construction requiring a plurality of radially extending cross braces. In the middle of the vessel, the agitator is provided, which here comprises two radially outwardly extending stirring arms.

It has been found that the mixing of the mash can be insufficient especially in the case of tough, relatively thick mashes in the upper region. In particular, a core can form in the center of the mash vessel, which rotates with the movement of the agitator, so that in particular in this area the mash is not thoroughly mixed.

Proceeding from this, the object of the invention is to provide a mash vessel which has a simple structure and can also mix high-viscosity mash or small mashes reliably.

According to the invention, this object is solved by the features of claim 1.

Characterized in that the agitator is arranged eccentrically in the housing, the mash is very well mixed, without additional flow breakers are required. A good mixing of the mash to the core is therefore guaranteed. Eccentric in the housing means here that the agitator axis and the central axis of the housing are spaced within the housing and at least do not intersect. Within The housing here, viewed from the lower peripheral edge of the floor upwards. Such an arrangement interferes with the formation of a symmetrical eddy current, but rather unbalanced flow movements result, with the result of constant intensive mixing of the partial streams and a resulting improved stirring result.

Preferably, the distance between the central axis L and agitator axis R at the level of a peripheral edge of the bottom part is 5 to 25%, preferably 10 to 20% of the housing diameter. At the level of the peripheral edge of the bottom part means here at an intersection of the agitator axis with a plane in which the peripheral edge. The solder from the intersection to the longitudinal axis then gives the distance. In this area results in a much better mixing of the mash.

Advantageously, the bottom part is designed such that it is inserted at a certain angle α, inclined to the central axis, in the housing, so that the peripheral edge of the bottom part lies in a plane inclined to the horizontal plane H. Preferably, the bottom part is formed such that it tapers from the peripheral edge of the bottom part upwards.

Such a floor can be easily realized without the need for elaborate bracing. Characterized in that the bottom is used inversely compared to the prior art and is also still inserted at a certain angle towards the central axis of the housing, the peripheral edge of the bottom extends in a plane which is inclined to the horizontal plane. By horizontal plane is meant here the plane which is perpendicular to the vessel wall.

This means that the mash can drain well from the deeper area without any leftovers in the mash jar. The fact that the bottom, viewed from the circumference, extends obliquely upward in the direction of the central axis L of the housing, results in a cavity below the floor which offers space for further elements. The shaft seal (stuffing box) of the stirrer can be welded directly into the topmost area of the floor, for example a cone point. The previously used outlet bowl can be completely eliminated. The height of the vessel is reduced, which is particularly advantageous in southern houses with a low platform height. It is particularly advantageous if the agitator axis R is inclined at an angle to the central axis of the housing. Due to the oblique and additionally eccentric installation of the agitator an even better mixing of the mash is achieved. At the same time, the conical bottom causes any core, which may be formed in the middle, to flow out of the mash, which is not well mixed, and thus also to be mixed. A uniform mixing of the mash to the core is ensured. In the solution according to the invention, the flow of the mash in the straight, cylindrical mash vessel constantly collapses and a partial flow is again flowed down to the bottom of the container at the edge.

Advantageously, the angle of inclination of the agitator axis to the central axis L is the same angle at which the bottom is inclined to the central axis L.

The bottom part may have a substantially conical bottom surface, the tip of which is arranged on the central axis L or eccentrically offset from the central axis L. If the tip lies on the center axis L, the agitator axis does not pass through the top of the bottom surface. If the tip of the conical bottom surface is arranged eccentrically to the longitudinal axis, the agitator can either be arranged so that the agitator axis passes through the top of the bottom surface, or can also be arranged offset to the tip.

Advantageously, a flange for guiding a stirrer shaft is joined at an angle to the horizontal plane in the bottom part, which preferably corresponds to the angle at which the peripheral edge of the bottom part is inclined to the horizontal. Thus, the most uniform possible distance between the at least one stirring blade and the bottom part.

Advantageously, the at least one stirring blade has at least one arm piece and an essentially U- or V-shaped end piece arranged thereon. The claw-shaped end piece results in a particularly good mixing. The tail advantageously has a length which corresponds to 30 to 50% of the length of the impeller arm.

The arm piece is advantageously formed as a flat material, which is employed at an angle of about 40 to 60 ° to the horizontal plane H.

Viewed in a longitudinal section of the housing, corresponds to the distance from one end of a rotating impeller to a first and closer side of the housing between 0.1 and 0.9 times the distance to the opposite and farther side of the housing. Thus, if the mash is conveyed obliquely upwards and the flow in the straight, cylindrical mash vessel collapses, the partial stream can flow well downwards through the larger distance to the side of the container.

The angle ε, under which the bottom part is inclined to the horizontal plane, is preferably in a range of 5 to 10 °.

The invention will be explained in more detail below with reference to the following figures.

Fig. 1 is a plan view of an agitator in a mash vessel according to an embodiment of the present invention.

FIG. 2 is a section along the line A-A in FIG. 1. FIG.

FIG. 3 is a section taken along the line B-B in FIG. 1. FIG.

Fig. 4 is a longitudinal section through another embodiment according to the present invention.

Fig. 5 is a schematic side view of a mash vessel according to the present invention.

Fig. 6 shows a perspective view of two superimposed pairs of impeller blades in a mash vessel according to the present invention.

Fig. 7 shows a mashing vessel according to the prior art.

Fig. 5 shows a rough schematic side view of a mash vessel 1, i. a mash tun or mash tun according to the present invention. The mashing vessel 1 has a housing 2, which here is essentially hollow-cylindrical. The housing 2 comprises a bottom part 9, which is here preferably inclined and will be explained in more detail below.

Furthermore, the mashing vessel 1 has a fume hood 11, a fume tube 14, a drive 13 for an agitator and an inlet 4 and a drain 5 for mash and / or cleaning liquid. Optionally, an inlet 60 for mash, in particular for dry meal, can be arranged in the upper region of the mash vessel 1. As can be seen in particular from Figures 1 and 2, the agitator 6 is arranged eccentrically in the housing 2 according to the invention. This means that the agitator axis R and the center axis L in the housing 2 are spaced from each other. In the housing here means viewed from a lower peripheral edge 15 of the bottom part 9 in the direction of the hood 11 that is, that the agitator axis 6 and the central axis L of the housing 2 in the housing 2 do not intersect.

According to the embodiment shown in Fig. 2, the bottom part 9 is formed so as to be viewed from the periphery 15 obliquely both in the direction of the center axis L and upwards, i.e., in the direction of the center axis L. in the direction of the hood 11 tapers. In addition, the bottom part 9 at an angle α, here z. B. angle α, inserted obliquely into the housing 2 to the central axis L and welded. The angle α is preferably in a range of 5 to 10 °, here about 5 °. The inclination of the bottom 9 implies that the circumference 15, i. the lower peripheral edge 15, which is fitted in the housing 2, lies in a plane E inclined to the horizontal plane H, the horizontal plane being a plane perpendicular to the housing walls. The angle ε between the peripheral edge of the bottom and the horizontal is then also at about 5 to 10 °.

In Fig. 2, the bottom part 9 is formed as an upwardly tapering cone whose open base is oval. The inclination results in that the mash is running on one side (in Fig. 2 to the left side), so that a discharge 5 for the mash in the bottom at the lowest point is arranged (see Fig. 5). The cone is here designed so that the conical bottom surface is inclined at an angle ß of about 5 to 20 ° to the cone base, the cone base is open and is limited by the peripheral edge 15. The bottom is preferably made of stainless steel sheet. Under the bottom of the cavity 10 results.

However, the invention is not limited to a conical bottom 9 with a corresponding tip S. The upwardly tapered bottom 9 can also run as a truncated cone or curved upwards.

In the mashing vessel 1, the agitator 6 is arranged. The agitator 6 is driven in rotation by the drive shaft 20 via the drive 13. Furthermore, the agitator 6 comprises at least one stirring blade 7, here with two arms extending radially outwards. The agitator 6 is, as noted above, eccentrically arranged in the housing. This results between the central axis L and agitator axis R a distance k. The distance k shown in Fig. 2 increases by the inclination of the agitator shaft 20 to the top. As shown in Figures 5 and 2, the distance k between the agitator axis R at the level of the peripheral edge and the central axis L is 5 to 25%, preferably 10 to 20% of the container diameter d (and is for example 300 to 500 mm). , with common mash vessel diameters from 3 to 7 m. At the level of the peripheral edge of the bottom part means here at an intersection of the agitator axis with a plane in which the peripheral edge. The perpendicular from the point of intersection to the longitudinal axis then gives the distance k. The agitator axis R is likewise inclined to the longitudinal axis L here. It is advantageous if the inclination angle of the agitator axis R to the central axis L substantially corresponds to the angle α, under which the bottom part 9 is inclined to the central axis L.

Advantageously, then the flange 21 for a waveguide at a certain angle, preferably the same angle ε as the conical bottom, welded. Thus, the most uniform possible distance between the Rührflügeln 7 and the bottom part can be accomplished.

The arms of the stirring blade 7 are adapted to the inclination ß of the bottom part 9 such that the most uniform distance between the stirring blades and the bottom part 7 can be achieved. The inclination angle φ, here the angle between the lower edge of an arm piece 7a to a horizontal, is in a range of 5 to 20 °.

In this embodiment, the tip S of the conical bottom surface is located on the central axis L. Here, it should be noted that the flange 21 extends to the tip S of the bottom part 9. As a result, the flow of the mash is not hindered by any edges. The flange 21 may also itself have a conical top, e.g. a 10 ° cone on the top, as shown in Fig. 2.

The stirring blade 7 itself here consists of two identical arms, each having an arm piece 7a and a substantially U-shaped or V-shaped end piece 7b arranged thereon. The V-shaped or U-shaped end piece is designed as a claw and outwardly, in the direction of the wall of the housing 2, opened. As can be seen in particular from FIG. 1, the U-shaped or V-shaped end piece 7b has a length I which corresponds to approximately 30 to 50% of the length of the agitator blade arm 7a. The arm piece 7a is advantageously designed as a flat material. formed whose width is at least 250 mm (with a diameter of the mash vessel of about 3 to 7 m).

As can be seen in particular from FIG. 3, the flat material of the arm piece 7a is set at an angle of 40 to 60 ° to the horizontal. The U- or V-shaped end piece 7b is welded with its closed or bent end at right angles to the flat material. The width of the end piece 7b corresponds to the width of the flat material.

2, the distance a2 from one end piece 7b to the housing wall 2b is greater than the distance a1 of this end piece from the opposite housing side 2a, due to the eccentric installation of the agitator 6, where a1 = 0.1 to 0, 9 x a2 is.

In the embodiment shown in Fig. 2, the tip of the cone lies on the longitudinal axis L.

The embodiment shown in Fig. 4 corresponds substantially to the embodiment shown in Fig. 2, but here the conical bottom 9 is eccentrically inserted into the housing 2, so that the tip S of the bottom part 9 is not on the central axis L lies. Here, the flange 21 is inserted in the region of the tip S in the bottom part 9. However, the flange 21 could also be used offset laterally to the tip S.

In the embodiments shown above, the agitator 6 is arranged so eccentric to the central axis L of the housing that it lies in the housing half, in which the outlet 5 is arranged for the mash (see Fig. 5).

Due to the oblique and additionally eccentric installation of the agitator 6 a much better mixing of the mash is achieved. At the same time, the conical bottom part 9 causes any core, which may arise in the middle, to flow out of unmixed mash to the outside and thus also be mixed. A uniform mixing of the mash to the core is ensured. The rectangular arrangement of the flat material 7a and the end piece 7b, an efficient mixing of the mash is also achieved. Due to the oblique installation of the flange 21 of the waveguide, the mash is conveyed obliquely upwards in the housing 2. The flow will collapse in a straight, cylindrical mash vessel 1 and a partial flow will preferably flow down to the bottom part 9 on the side of the agitator which has an increased distance a2 from the housing wall 2b. This means that the ex- centric installation further supports the above effect. Flow breakers are not required in such an arrangement.

As is evident in particular from FIG. 6, according to the present invention it is also possible to use an agitator which has a plurality of stirring blades 7 arranged one above the other. The example shown in FIG. 6 has two mutually perpendicular agitator blades 7 arranged one above the other.

Although the embodiments have been shown in FIGS. 1 to 5 in connection with an obliquely inserted, conical bottom, it is also already advantageous to arrange the agitator eccentrically in a conventional floor, the floor 9 is straight or at a certain angle to the outlet is inclined (see 9 'Fig. 6).

Claims

claims 1. mash vessel (1), comprising: a housing (2) with a central axis (L) and with a bottom part (9) as well an agitator (6) with at least one agitator blade (7), characterized in that the agitator (6) is arranged eccentrically in the housing (2), such that the agitator axis (R) and the central axis (L) in the housing (2) are spaced apart. 2. mash vessel (1) according to claim 1, characterized in that the distance (k) between the central axis (L) and agitator axis (R) at the level of a peripheral edge (15) of the bottom part 5 to 25, preferably 10 to 20% of the container diameter ( d) is. 3. mashing vessel (1) according to claim 1 or 2, characterized in that the bottom part (9) at a certain angle (α) inclined to the central axis (L) is inserted into the housing, so that the peripheral edge (15) of the bottom part ( 9) lies in a plane (E) inclined to the horizontal plane (H). 4. mashing vessel according to claim 3, characterized in that the bottom part is formed such that it tapers from the peripheral edge (15) of the bottom part (9) upwards. 5. mashing vessel (1) according to at least one of claims 1 to 4, characterized in that the agitator axis (R) at an angle (α) to the central axis (L) of the housing is inclined. 6. mash vessel (1) according to claim 5, characterized in that the inclination angle (α) of the agitator axis (R) corresponds to the inclination angle (α) of the bottom part to the central axis (L). 7. mashing vessel (1) according to at least one of claims 3 to 6, characterized in that the bottom part (9) has a substantially conical bottom surface has its tip on the central axis (L) or eccentrically offset from the central axis (L) is arranged. 8. mash vessel (1) according to at least one of claims 3 to 7, characterized in that a flange (21) for guiding a agitator shaft (20) is joined at an angle to the horizontal plane in the bottom part (9), preferably the angle (ε) corresponds to below which the peripheral edge (15) is inclined to a horizontal plane. 9. mashing vessel (1) according to at least one of claims 1 to 8, characterized in that the at least one stirring blade (7) has at least one arm piece (7a) and a substantially U- or V-shaped end piece (7b) arranged thereon. 10. mashing vessel (1) according to claim 9, characterized in that the U- or V-shaped end piece (7b) has a length which corresponds to 30 to 50% of the length of the Rührflügelarms (7a). 11. mash vessel (1) according to at least one of claims 8 or 10, characterized in that the arm piece (7a) is formed as a flat material which is employed at an angle of 40 to 60 degrees to the horizontal plane (H). 12. mashing vessel (1) according to at least one of claims 1 to 11, characterized in that viewed in a longitudinal section of the housing (2), the distance (a1) from one end of a rotating stirring blade (7) to a first and closer housing side ( 2a) corresponds to between 0.1 and 0.9 times the distance (a2) to the opposite and more distant side of the housing (2b). 13. mashing vessel (1) according to claim 3, characterized in that the angle (ε) under the bottom part inclined to the horizontal plane is 5 to 10 degrees.