Patent Grant
10799840
The invention relates to a stirring member for an industrial stirrer, in particular for a stirring rod arrangement, for connecting to a stirring mechanism combinable with a container for receiving liquids, wherein the container comprises a filling opening closable with a lid for filling the container in an upper bottom wall, wherein the stirring member is connectable to a rod-shaped stirring member carrier of the stirring rod arrangement, wherein the stirring member comprises a bearing end and a stirring member end connected to the bearing end via a link or crosspiece, respectively, and having a flow tube, wherein the flow tube comprises a tube wall.
A stirring member in a stirring rod arrangement of the make mentioned above is known from DE 20 2014 002 901 U1. The known stirring members of the stirring rod arrangement are pivoted against the stirring member carrier in a mounting configuration, in which the stirring rod arrangement can be inserted into in a container for receiving liquids, and are secured to the stirring member carrier in this position via a locking connection. The stirring members as such are pivotably mounted at a stirring member carrier at a bearing end and comprise a link starting from the bearing end, a flow tube being attached to the end of said link. The flow tube is cone-shaped and comprises a flow inlet cross section which is larger than the flow outlet cross section.
A stirring member is known from DE 10 2008 063 393 B3 which comprises an annular accumulating surface. The accumulating surface is arranged in an inflow plane of a flow inlet cross section of an opening of the stirring member. A flow tube is formed in the shape of a flange at the accumulating surface, i.e. the opening.
A disadvantage of the known stirring members is that depending on viscosity and flow behavior, a satisfactory mixing of the liquid to be mixed cannot be achieved. Simultaneously, it is desirable to realize a stable centering of the stirring members on a rotational path of the stirring rod arrangement.
The object of the invention at hand is to propose a stirring member and stirring rod arrangement which comprise improved mixing characteristics.
The object is attained by a stirring member having the features of claim 1, a stirring rod arrangement having the features of claim 11 and a transport and storage container having the features of claim 15.
The stirring member for an industrial stirrer, according to the invention, in particular for a stirring rod arrangement for connecting to a stirring mechanism combinable with a container for receiving liquids, wherein the container comprises a filling opening closable with a lid for filling the container in an upper bottom wall, is connectable to a rod-shaped stirring member carrier of the stirring rod arrangement, wherein the stirring member comprises a bearing end and a stirring member end connected to the bearing end via a link or crosspiece, respectively, and having a flow tube, wherein the flow tube comprises a tube wall, wherein the flow tube comprises an circularly formed accumulating surface at its flow inlet cross section, wherein the accumulating surface comprises at least one circular ring sector which is inclined with respect to an inflow plane of the flow inlet cross section.
By means of the circularly formed accumulating surface, which comprises at least one circular ring sector inclined with respect to an inflow plane of the flow inlet cross section, an additional force acting on the stirring members can be generated at a defined position, said force serving to influence a relative movement of the stirring member end in the flow environment. Simultaneously, the circularly formed accumulating surface enables a very good mixing of a liquid to be mixed, since a swirling of the liquid is realized. Simultaneously, the force produced at the stirring member via the inclined circular ring sector can stabilize or center the stirring member insofar that a steady and low-vibration rotation of the stirring rod arrangement is possible on a rotational path despite the swirling produced in the liquid to be mixed via the accumulating surface.
In an embodiment of the stirring member, it can be provided that the inclined circular ring sector extends over at least 90°, preferably at least 180°, particularly preferably at least 270°, of the accumulating surface based on an circular ring center. Depending on the viscosity and flow behavior of the liquid to be mixed, the inclined circular ring sector can be adjusted accordingly to the mixing task. The inclined circular ring sector can be arranged opposite a contact surface or level partial surface, respectively, of the link, based relatively on the circular ring center.
Furthermore, the accumulating surface can comprise at least one surface sector inclined at a surface sector angle ζ with respect to a level partial surface of the accumulating surface, wherein the surface sector angle ζ can preferably be 10°. The surface sector can then be formed levelly, for example. The surface sector angle ζ can also be 5° or up to 20°, for example.
In another embodiment of the invention, the inclined circular ring sector can extend over more than 360° of the accumulating surface based relatively on an circular ring center. Consequently, the entire accumulating surface can be inclined with respect to the inflow plane of the flow inlet cross section.
The circular ring sector can also be inclined at a surface sector angle ζ, wherein the surface sector angle can be formed consistently. Thus, the accumulating surface can be cone-shaped or funnel-shaped, wherein the accumulating surface forms a comparatively flat cone as a type of funnel with respect to the flow tube. A surface sector angle ζ of the cone can be 5° to 20°, preferably 10°. The surface sector angle ζ is measured at an edge of the circular ring sector and can vary by +/−1°.
Furthermore, the circular ring sector can be inclined by a surface sector angle ζ, wherein the surface sector angle is continuously changed along the circular ring sector according to a non-linear, preferably trigonometric, function, wherein sections of the surface sector angle ζ can be at least 5° to 20°, preferably 10°. Such a function can, for example, be a sine function, so that the circular ring sector can be formed wavelike in its radial progression. By means of this wavelike design of the circular ring sector, a better centering of the stirring member can be realized.
The circular ring sector can also be tilted by a surface sector angle ζ, wherein the surface sector angle can increase steadily relative to an circular ring center or an circular ring center axis, respectively, with a decreasing distance of the accumulating surface. The surface sector angle ζ can consequently be formed steady, linearly variable, for example, relative to the circular ring center or relative to an outer edge plane formed by an outer edge of the accumulating surface, so that a possibly improved inflow behavior of liquid into the flow tube is enabled. The surface sector angle ζ can be 5° to 20°, preferably 10°, to the outer edge plane at the outer edge of the accumulating surface.
The accumulating surface can be formed as a bell-shaped opening, for example. The opening can be formed as either a trumpet-shaped or bugle-shaped opening, wherein a possibly laminar flow within the flow tube can be thusly achieved, which favors a low-vibration rotation of stirring members.
In another advantageous embodiment of the invention, the circular ring sector can be inclined by a surface sector angle ζ, wherein the surface sector angle can be continuously changed according to a non-linear, preferably trigonometric, function as the distance of the accumulating surface relative to an circular ring center changes, wherein sections of the surface sector angle ζ can be 5° to 20°, preferably 10°. The circular ring sector can then be continuously changed in the type of a wave starting from the circular ring center.
Accordingly, the accumulating surface can be formed as a wavelike opening. The circular ring sector can form, for example, several sine-shaped waves.
If the tube wall is formed in such a way that the length of the tube wall in a cut perpendicular to the longitudinal axis of the link above a tube axis is larger than below the tube axis, a surface profile longer in the flow direction is formed above the tube axis than below the flow axis, so that the lift force acting on the stirring member ends is increased and a stabilizing of the stirring member ends in the liquid flow is consequently realized during operation.
If, in addition, a surface base of a lift surface formed by an upper part of the tube wall is inclined at an angle of attack to the inflow direction, a desired lift force can be adjusted at the stirring member ends by choosing the angle of attack as a function of the rotational speed of the stirring rod arrangement. Thus, it is possible, for example, to carry out a special adjustment of the stirring rod arrangement to the viscosity or other material consistency of the liquids to be mixed via an adequately chosen angle of attack.
Preferably, the tube wall is formed as a slanted cone in such a way that a flow inlet cross section of the flow tube is inclined to a flow outlet cross section of the flow tube under a tube angle, so that an influencing of the lift force is possible here as well.
If the flow tube comprises the accumulating edge having the circularly formed accumulating surface at the flow inlet cross section, the accumulating surface abutting to a link surface of the link, a desired flow resistance of the stirring member can also be adjusted depending on the embodiment and size of the accumulating surface.
It is particularly advantageous if the accumulating surface is inclined by an accumulating surface angle in the inflow direction with respect to the rotational axis, so that the flow resistance is adjustable via the accumulating surface angle disregarding the surface size of the accumulating surface.
If a lift pocket is formed in a middle section of the link or crosspiece, respectively, said lift pocket having a lift surface inclined by an inclination angle in the flow direction with respect to the rotational axis and inclined at an angle of attack with respect to the inflow direction, the lift behavior or the flow resistance behavior, respectively, of the stirring member can be influenced by a corresponding design of the link surface via an adequately chosen angle.
The stirring rod arrangement, according to the invention for an industrial stirrer, in particular for connecting to a stirring mechanism combinable with a container for receiving liquids, wherein the container comprises a filling opening closable with a lid for filling the container in an upper bottom wall, comprises a rod-shaped stirring member carrier formed as a hollow shaft for receiving a stirring mechanism shaft, wherein the stirring rod arrangement comprises stirring members pivotably connected to the stirring member carrier according to the invention. In an operational configuration, the stirring members can then take up a pivoted position at a stirring angle δ with respect to the rotational axis in consequence of a rotation of the stirring member carrier, the pivoted position being dependent on the rotational speed of the stirring member carrier, in such a way that the free stirring member ends are arranged in a stirring member distance r from the rotational axis. Further advantageous embodiments of a stirring rod arrangement can be found in the dependent claims of claim 1.
In a mounting configuration, a free stirring member end of the stirring members can be pivoted against a rotational axis of the stirring member carrier, wherein a spring device can be arranged between the stirring members and the stirring member carrier in such a way that a centrifugal force is applied to the stirring members in an operational configuration in consequence of a rotation of the stirring member carrier and the stirring members take up a pivoted position, which is dependent on the rotational speed of the stirring member carrier, at an angle δ formed with respect to the rotational axis, wherein the free stirring member ends are arranged in a stirring distance r from the rotational axis and the spring force acts against the centrifugal force, the spring force becoming stronger as the stirring angle increases. Accordingly, an automatic upward pivoting of the stirring members can take place in such a way that the stirring member ends are pivoted upward in consequence of the centrifugal force acting on the stirring member ends and are arranged in a stirring distance from the rotational axis when the stirring rod arrangements are in operation. Thereby, it is not only possible to carry out the adjustment of the stirring members from the mounting configuration to the operational configuration without manual intervention. Furthermore, the desired distance of the stirring member ends to the stirring member carrier can be adjusted via an adequately chosen rotational frequency. The spring force acts as a restoring force which counteracts the centrifugal force and causes a restoring of the stirring member ends against the rotational axis when the rotational speed is decreasing. Thereby, in particular residual amounts of the liquid in the container, which accumulate in a narrowed bottom region of the container, can be stirred, without the risk of the stirring member ends colliding with the container wall. The restoring spring action also has the effect that even stirring members of a low-density material do not float in a liquid of comparable density but instead are active in a desired stirring depth in the liquid.
It is particularly advantageous if the free stirring member ends of the stirring member are arranged beneath pivot bearings formed at the stirring member carrier in the mounting configuration, since consequently the stirring members can be directly pivoted against each other in the mounting configuration, so that the cross section essential for the insertion of the stirring rod arrangement via the filling opening of the container into the container is made as small as possible in the area of the stirring members pivoted against each other.
If the spring device is formed as a leg spring, the cross section minimization mentioned above in particular can be supported, since the leg spring is installable on the stirring members so as to be located radially outside while radially protruding as little as possible. Preferably, a leg of the leg spring is supported above the pivot bearing at the stirring member carrier and the other leg of the leg spring supports itself at the stirring member.
In another preferred embodiment of the invention, the spring device is formed as a spiral spring, which requires an installation space as small as possible. For example, an end of the spiral spring can be arranged at a pivot pin of the pivot bearing and the other end can be arranged at the stirring member.
If the spring device is formed as an electrically conductive connection between the stirring member carrier and the stirring member, a safe electrostatic discharge, which is independent to the formation of the pivot hearing, can take place from the liquid to be mixed via the stirring members into the stirring member carrier.
It is particularly advantageous if the spring device is made of an electrically conductive plastic, wherein all components of the stirring rod arrangement can be made of plastic, preferably an electrically conductive plastic, in a particularly preferred embodiment of the invention. The stirring member as such can therefore be injected in one piece, for example as an injection molding piece, made of electrically conductive plastic.
If the spring device is formed out of a material extension formed at the stirring member, it is possible to form the spring device together with the stirring member in one single process step, for example an injection molding step. Moreover, an integral connection between the spring device and the stirring member is thereby realized, so that special, separately formed linking devices are not necessary.
This is also the case for the connection of the spring device with the stirring member if the spring device is connected in a form fitting manner with a free connection end, for example via a locking connection, to the stirring member carrier.
Independently from the arrangement of the spring device at the stirring rod arrangement, it is also advantageous if the stirring members, in a stirring rod arrangement of the make mentioned above, are made of electrically conductive plastic.
Preferably, the stirring member carrier comprises a connection device for connecting the lid at its upper axial end, wherein the connection device comprises an axial abutment for contacting against a supporting edge formed in the bottom of a plug depression formed in the lid for receiving a drum plug, said supporting edge limiting a through link opening formed in the bottom. By this means, it is possible for the stirring rod arrangement to also be connected with the container by means of the lid independently of a stirring mechanism combined with the stirring rod arrangement. Thereby, the stirring rod arrangement can also be arranged, or remain, at a container without a stirring mechanism having to necessarily be coupled with the stirring rod arrangement.
The aforementioned advantageous embodiment of the stirring rod arrangement having the connecting device arranged at its upper axial end thereby proves to be advantageous independent of the remaining design of the stirring member carrier, also in particular independent of whether a spring device is arranged between the stirring members and the stirring member carrier and in particular also independent of how the stirring members are designed.
If the abutment of the connecting device described above is formed by a circlip received in a circlip receiver of the connecting device, this circlip can have a particularly simple design on the one hand and the embodiment of the abutment as a circlip which abuts on the supporting edge enables a rotational movement between the stirring rod arrangement and the lid if necessary, on the other hand. Preferably, the circlip abuts on the supporting edge only during a standstill of the stirring rod arrangement, whereas the circlip is lifted off of the supporting edge during a rotation of the stirring rod arrangement with respect to the lid in order to avoid friction and abrasions in particularly caused by friction and thus possible impurities of the liquid received in the container.
Preferably, the circlip receiver is formed as a separate component which is connected to the stirring member carrier in a form-fitting manner in order to form the connecting device.
Alternatively, however, it is also possible to integrally form the circlip receiver with the stirring member carrier.
It is particularly preferred if the circlip receiver is formed by a material extension formed at the stirring member carrier, said material extension being produced by a reshaping method at the contour of the stirring member carrier, for example.
If the stirring member carrier comprises a connecting device, formed at the lower axial end as a shaft hub, for connecting the stirring members, wherein the connecting device is connected in a form-fitting manner to the stirring member carrier and comprises bearing pins for connecting to the stirring members and for forming pivot bearings, the stirring member carrier can be designed particularly simply and the comparatively complexly formed connecting device can be produced separately. The forming of the connecting device at the stirring member carrier can then be carried out by simply producing the form-fitting connection between the connecting device and the stirring member carrier.
It is particularly advantageous if the connecting device simultaneously serves to connect the stirring mechanism shaft of the stirring mechanism.
If the connection of the connecting device to the stirring mechanism shaft is formed in a form-fitting manner, this connection can also be carried out in a simple manner without the use of tools.
Preferably, the connecting device comprises a first form-fitting linking device for transferring the turning moment of the stirring mechanism shaft onto the stirring members and a second linking device for axially securing the connecting device onto the stirring mechanism shaft, so that not only a safe transferal of the turning moment from the stirring mechanism shaft onto the stirring rod arrangement can be carried out by a form-fitting linking device, but additionally the axial securing of a defined axial relative position between the stirring mechanism shaft and the stirring rod arrangement via a form-fitting linking device is carried out as well.
Preferably, the stirring rod arrangement is formed in such a way that it is connected to the lid and can be inserted into a filling opening of a container as a mounting unit together with the lid and can be connected to the container by means of a connection of the lid to the filling opening of the container, so that a stirring rod arrangement and a container can be combined in such a manner that the combination is secured to the container by simply replacing the lid standardly arranged on the filling opening of the container with a lid connected as a mounting unit to the stirring rod arrangement.
Preferably, the lid is provided with a drum plug arranged in a plug depression of the lid for securing the connection of the lid to the stirring rod arrangement and for forming a captive linking of the lid to the stirring rod arrangement in such a way that the circlip is received in a circlip receiver space, axially defined on both sides, of the stirring rod arrangement formed as a mounting unit.
The invention at hand also relates particularly to a transport and storage container for liquids having a container formed as an internal container made of plastic, said container comprising a filling opening closable with a lid for filling the container in an upper bottom wall, and an outlet connection arranged at the front side for connecting an outlet fitting, as well as a lower bottom wall connecting two lateral walls, a rear wall and a front wall of the container for supporting the container on a pallet floor of a transport pallet having an outer jacket for receiving the container, wherein the lid of the container is provided with a stirring rod arrangement according to the advantageous embodiments of the invention described above.
In the following, the invention is further described by means of the drawings.
In the figures:
The upper bottom wall 26 is provided with a filling connection 27 closable with a lid 28 formed a screw-on lid in this case.
In the illustrated embodiment, the lid 28 forms a component of a stirring rod arrangement 29, the latter comprising as essential components a stirring member carrier 30 formed as a hollow shaft made of electrically conductive plastic in the case at hand as well as a stirring rod arrangement 31, which comprises three stirring members 32 in the case of the embodiment at hand, said stirring members connected to the stirring member carrier 30 by means of a shaft hub 33.
As in particular a synopsis of
The leg springs 34 are formed, like the stirring members 32 and the shaft hub 33, out of an electrically conductive plastic material analog to the stirring member carrier 30.
In
As in particular a synopsis of
As a comparison of
As in particular a synopsis of
As further shown in
A stirring member 82 is illustrated in
As in particular
The two surface segments are formed levelly in the embodiment illustrated and further comprise a conforming size in the case at hand.
Apart from the stirring member end 83, which comprises the accumulating surface 84 instead of the accumulating surface 51, the stirring member 82 illustrated in
As in particular a synopsis of
As is in particular illustrated in
If the drum plug 75 is now screwed into the plug depression 76 of the lid 28, a lower edge 80 of the drum plug 75 now limits a ring receiving space 81 together with the supporting edge 79 of the lid 28, in which the circlip can carry out a limited or essentially no axial movement, if anything, so that a secure connection between the lid 28 and the stirring member carrier 30 is formed.
In this way, the container 20 can be combined with a stirring rod arrangement 29 independent of the installation of a stirring mechanism as well. If a stirring mechanism is to be connected to the stirring rod arrangement 29 in order to mix a liquid received in the container, it will suffice to remove the drum plug 75 from the plug depression 76 of the lid 28 and to insert the stirring mechanism shaft 38 into the stirring member carrier 30 from above and to couple the two. Thereby the stirring mechanism can be set on and connected to the container 20 or a support structure connected to the outer jacket of the container 20, respectively, as usual. Preferably, a slight axial lifting of the stirring member carrier 30 out of the container 20 is carried out, as illustrated by way of example in
A synopsis of
A synopsis of
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2015 011 967 | Sep 2015 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/069116 | 8/11/2016 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2017/045846 | 3/23/2017 | WO | A |
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| 20180236419 A1 | Aug 2018 | US |
