Patent Application
20140177379
This application claims priority to JP 2012-280988, filed on Dec. 25, 2012, entitled “Mixing Device”, which are herein incorporated by reference for all purposes.
The present invention relates to a mixing device and more particularly to a mixing device that can enhance mixing capabilities for mixing liquids in a mixing tank.
Conventional mixing devices were structured such that an impeller-type mixing member was attached to a shaft (See patent documents 1 and 2).
In contrast, certain mixing devices do not have the configuration of impeller blades being attached to a mixing member. A cross-section of a circular shaped mixer body, as described in Patent Document 3, proposes a structure in which flow passages link inlet ports and outlet ports so as to blend two or more fluids, uniformly disperse powder added to a fluid, and to avoid damage and fluid contaminants associated with impeller blade mixing operation.
(Patent Document 1) Unexamined Japanese Patent Publication 2010-230420
(Patent Document 2) US 2010/00894281A1
(Patent Document 3) Patent No. 4418019
In consideration of the above points, the present invention proposes a non-impeller-type mixing device with an improved mixing function so that dangers associated with operating an impeller blade-type mixer and the disadvantage of hazardous objects entering into the fluid being mixed can be overcome.
In order to solve the problem, the present invention provides a mixer body 5 that rotates around the center axis line L1 of a cylindrical housing 21 which is a cylindrical rotating member 13 via a rotating drive shaft 11 connected to a top plate 13A that encloses the upper end of the cylindrical housing 21. The cylindrical rotating member 13 has a plurality of discharge ports 22A-22D formed in the peripheral surface of the cylindrical housing 21. Provided at the inner peripheral surface of the cylindrical housing 21 are a plurality of inwardly, projecting extruded plate portions 24A-24D. Provided at the bottom end of the cylindrical housing 21 is a suction port 23, 30. When the cylindrical rotating member 13 rotates, the extruded plate portions 24A-24D cause an inner circulation current fin which the liquid to be mixed 4 circulates around the center axis line L1. A portion of the liquid to be mixed 4, that forms the inner circulation current f, is discharged outwardly, as outer discharge current d1-d4, by centrifugal force through discharge ports 22A-22D. At the same time, the liquid to be mixed 4 that is outside the cylindrical rotating member 13 is sucked into the cylindrical rotating member 13 as suction current e1-e3, h1-h4 via suction ports 23, 30.
According to the present invention, inside the cylindrical housing, which acts as a cylindrical rotating member, are extruded plate portions that cause an inner circulation current of the liquid to be mixed when the cylindrical housing is rotated. Centrifugal force discharges a portion of the inner circulation current outwardly via discharge ports provided in the cylindrical housing. At the same time, liquid to be mixed that is outside the cylindrical housing is drawn therein as suction current via suction ports thus mixing the liquid in the mixing tank.
A first embodiment of the present invention will now be described with reference to the drawings.
In
The mixer body 5 extends vertically from a rotation drive portion 10 and is attached to a lower end of a rotating drive shaft 11. The rotating drive shaft 11 extends vertically and is driven by rotation drive portion 10 around a center axis line L1.
As shown in
The rotating member 13, to which the upper surface and lower surface of the respective top plate 13A and bottom plate 13B are attached, has a cylindrical housing 21 made of a thin sheet of metal. In the outer surface of the cylindrical housing 21, as shown in
In this embodiment, the arrangement of the discharge ports 22A-22D is that they are formed vertically at intermediate positions in two levels in the cylindrical housing 21. Accordingly, there are 8 discharge ports formed in the cylindrical outer peripheral surface of the cylindrical rotating member 13 at 90 degree intervals.
At the end edges of the discharge ports 22A, 22B, 22C and 22D of the cylindrical housing 21 at the rotation direction b side, extruded plate portions 24A, 24B, 24C and 24D are formed in the direction toward the central axis line L1 side. Accordingly, when the cylindrical housing 21 containing the liquid to be mixed 4 is rotated in the rotation direction b, the liquid to be mixed 4 is forced out by the extruded plate portions 24A, 24B, 24C and 24D through discharge ports 22A, 22B, 22C and 22D to which said extruded plate portions 24A, 24B, 24C and 24D are adjacent thereto.
According to the above configuration, when the mixer body 5 has been inserted into the liquid to be mixed 4 and rotated by the rotation drive portion 10 in the direction of arrow a, the space between the extruded plate portion 24A of the discharge port 22A and the extruded plate portion 24B of discharge port 22B, the space between the extruded plate portion 24B of discharge port 22B and the extruded plate portion 24C of discharge port 22C, the space between the extruded plate portion 24C of discharge port 22C and the extruded plate portion 24D of discharge port 22D and the space between the extruded plate portion 24D of discharge port 22D and the extruded plate portion 24A of discharge port 22A at the circumferential surface of the cylindrical housing 5, moves in the same direction as arrow a as is illustrated by arrows c1, c2, c3 and c4.
At this time, as the above mentioned portions each move in the direction of c1, c2, c3 and c4, a portion of the liquid to be mixed 4 inside the cylindrical housing 21 comes in contact with the center portion of the cylindrical housing 21 and is drawn along by the movement.
From this, after the cylindrical rotation member 13 starts rotating and a stable rotation state is attained, the rotation operation draws along the liquid to be mixed 4 at the extruded plate portions 24A-24D. The rotation speed of the liquid to be mixed 4 around the center axis line L1 is the same rotation speed of the rotation drive shaft 11 (This is called inner circulation current f.).
The outer side of the liquid to be mixed 4, that forms the inner circulation current f, is drawn along by the rotation. The liquid to be mixed 4 centered around then central axis line L1 is dispersed outward by centrifugal force.
In due course, a portion of the inner circulation current f of the liquid to be mixed 4 that has been acted upon by centrifugal force, is discharged, as shown by arrows d1-d4 in
With this embodiment, when discharge ports 22A-22D are punched in the outer circumference of the metal sheet portion of the cylindrical housing 21, plate members are positioned at the outer circumferential edge of the discharge ports 22A-22D forming a gap. These plate members are folded inward after machining to form extruded plate portions 24A-24D.
In that case, if the fold angle relative to the inner side surface of the cylindrical housing 21 is, for example 45 degrees and if the cylindrical rotation member 13 is rotated, the extruded plate portions 24A-24D push the liquid to be mixed 4 in direction of the center axis line L1. In this way, the inner circulation current f forming operation can be easily carried out by the extruded plate portions 24A-24D.
At this time, only the portion of the liquid to be mixed 4 inside the cylindrical housing 21 that was dispersed as an outer discharge current d1-d4 is subject to negative pressure. As a result and as shown in
At the time of this flow of the liquid to be mixed 4 that is inside the cylindrical housing 21, the outer discharge current d1-d4 is discharged from the discharge ports 22A-22D at the same time that suction current e1-e3 occurs from the suction tube 23. As a result, the liquid to be mixed 4 that is drawn into the suction tube 23 and after the inner circulation current f centers around the central axis line L1 of the cylindrical housing 21, a portion of the inner circulation current f is discharged outward as an outer discharge current d1-d4 to become a mixing current of the liquid to be mixed 4.
With the above configuration, the rotation of the cylindrical member 13 causes the occurrence of inner circulation current f therein. At the same time, centrifugal force causes a portion of the liquid to be mixed 4, as outer discharge current d1-d4, to go against the current. In addition, negative pressure is used to draw liquid 4 in the mixing tank 3 into the cylindrical housing and around the cylindrical rotating member 13, as indicated by the suction current e1-e3. The cylindrical rotating member 13 stirs and mixes the liquid. This produces a homogenized liquid in the mixing tank.
As the liquid to be mixed 4 as a whole can be engulfed in the mixing current, even if the mixing tank 3 is cylindrical or a quadrate or other shape, a uniform mixture can be made.
Actually, the discharge power of the outer discharge current d1-d4 and the suction power of the suction current e1-e3 can be controlled by appropriately determining the RPM of the cylindrical rotation member 13 thus enhancing the mixing function. In this way, the type of mix needed for the mixing tank 3, for example a gentle mix when a liquid to be mixed 4 is of low viscosity or a strong mix when a liquid to be mixed has a high specific gravity ratio or viscosity, can be determined.
In addition, in order to clean the mixer body 5, one simply needs to replace the liquid to be mixed 4 in the mixing tank, with a cleaning liquid (e.g. clean washing water, methanol, etc.) and perform the foregoing mixing operation. Thereafter, the spent mixing liquid is discarded thus obtaining a practical, sufficient cleaning.
As
In the case of
Regarding the configuration in
At this time, an inner circulation current f is generated inside the cylindrical housing 21 by the occurrence of a discharge current d1-d4 causing a negative pressure to the liquid to be mixed 4 that is above the discharge ports 22A-22D of the cylindrical housing 21. As a result, the liquid to be mixed 4 above the upper plate 13A is drawn into the cylindrical rotation member 13, as indicated by arrows g1-g4, as a suction current.
At the same time that a suction current e1-e3 is being formed at the lower portion of the cylindrical rotation member 13 that is inside the mixing tank 3, an intake current g1-g4 is formed at the upper part of the cylindrical rotation member 13 via intake ports 25A-25D.
In this case, because the intake current g1-g4 occurs in the vicinity of the surface of the liquid to be mixed 4 and serves as a water surface interface, the mixer body 5 is able to intermix air into the liquid to be mixed 4 thus forming bubbles at the liquid surface because the mixing function draws air therein. (This is called aerobic mixing.)
In relation to this, in the cases of the above-mentioned
As
The configuration of the mixing device 1 according to this embodiment, is that the suction tube 23 and the lower plate 13B of the cylindrical rotation device 13 of
As a result, the bottom of the cylindrical rotation member 13 is a cylindrical shaped communication hole 30, the diameter of which corresponds to the diameter of the cylindrical housing 21. The same symbols as shown in
In this case, if the cylindrical rotation member 13 is set so that the space between the bottom plate 3A of the mixing tank 3 and the bottom edge of the cylindrical rotation member 13 of the mixer body 5 is narrow, a strong suction strength of the mixing device 1, with respect to the liquid to be mixed 4 around the periphery of the bottom plate 3A of the mixing tank 3, can be obtained.
(4-1) The anaerobic mixing embodiments such as in
In particular, when aerobic mixing in
From this, thorough mixing can be made even if the liquid to be mixed 4 is of high viscosity or contains particles such as a liquid to be mixed at a sewage treatment facility.
(4-2) Regarding the above embodiments, the case was discussed where the cylindrical rotation member 13 has discharge ports 22A-22D, each having an extruded plate 24A-24D, formed vertically therein at two levels. However, the number of vertical levels formed is not limited to 2. There can be more than two levels and there can be more than 2 discharge ports in one level. The point is that these configurations obtain the same effect as above since an inner circulation current f is formed at the central axis line and centrifugal force creates a plurality of outer discharge currents via discharge ports.
(4-3) Regarding the embodiments discussed above, the cylindrical housing 21 is made of a thin sheet of metal into which discharge ports 22A-22D are cut in the outer surface forming a gap. The plate portions are folded inward at 45 degrees to form extruded plate portions 24A-24D. However, the fold angle may be other than 45 degrees and the shape of the extruded plate portions 24A-24D may be adjusted to more easily form an inner circulation current.
(4-4) In addition, the vertical positioning relationship of the discharge ports 22A-22D and the extruded plate portions 24A-24D may be changed from one in which the heights are the same to one in which they are mutually shifted. In other words, it is sufficient as long as an inner circulation current f is formed inside the cylindrical rotation member 13 by the movement of the extruded plate portions 24A-24D and a portion of the inner circulation current f is discharged via discharge ports 22A-22D by centrifugal force.
(4-5) Regarding the embodiments of
In this case, the pipe shaped rotation drive shaft 11 is configured so that the upper end is above the liquid to be mixed 4 so as to discharge air. This causes a negative pressure to occur inside the cylindrical housing 21 when a portion of the inner circulation current f is discharged outward as an outer discharge current d1-d4. Air is thus mixed into the liquid to be mixed 4 that is inside the cylindrical housing 21 via the hollow portion of the rotation drive shaft 11.
Thus, a mixing device that enables aerobic mixing can be achieved.
In this way, when the rotation drive shaft 11 is in the shape of a pipe, the length of the pipe does not have to stop at the upper plate 13A but can pass through the upper plate 13A and into the cylindrical housing 21.
When applied to the embodiments in
The present invention can be used for mixing a liquid to be mixed in a mixing tank.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-280988 | Dec 2012 | JP | national |
