JP4410483B2 - Stir and mix pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stirring and mixing pump for mixing and supplying a mixed flow obtained by mixing a liquid and plastic strips before being supplied to a processing apparatus.
[0002]
[Prior art]
Plastics are widely used in modern life and are discarded in large quantities from various fields. In recent years, various sports drinks, mineral water, and tea have been sold at vending machines and have been increasing every year, and many used PET bottles have been discarded as they are sold at convenience stores. ing. These plastics are expected to be separated with high precision according to the type of plastics for the production of recycled fibers, and the use of recycled plastics or oils.
[0003]
There is a specific gravity separation method for separating plastic pieces, but in order to separate various plastics with high accuracy, for example, it is necessary to mix plastic pieces crushed to about 5 to 30 mm well with specific gravity liquid, Conventionally, a mixing agitation tank having an agitation blade inside is provided in front of a pump.
[0004]
[Problems to be solved by the invention]
If a mixing agitation tank is separately provided in the previous stage of the pump, the mixing agitation tank requires a relatively large installation location and piping to the pump, and a rotation driving motor for the agitation blades must also be provided separately. Further, when the distance to the pump is long, there is a tendency that a deviation occurs in the density of the mixture with respect to the liquid.
[0005]
The present invention has been devised in view of the above, and an object thereof is to provide a solid piece stirring and mixing pump that is excellent in reducing the space occupied by the mixing apparatus, can omit piping, and has high stirring and mixing ability. It is said.
[0006]
[Means for Solving the Problems]
The stirring and mixing pump of the present invention is provided with a casing having a stirring blade for mixing and stirring directly connected to the pump shaft on the suction port side of the spiral pump body, and the solid pieces and liquid in the mixed flow are previously stirred in the casing. Mix and immediately suck into the centrifugal pump body and then deliver.
[0007]
In the present invention, a stirring blade for stirring and mixing is directly driven by a pump rotation shaft, and a mixed flow composed of solid pieces and liquid is stirred and mixed in a casing, and immediately after that, the pump body sucks, so that the fixed piece sinks. The pump can be supplied to the pump without providing a margin for separation. Therefore, the mixed liquid from the pump outlet is excellent in mixing uniformity of the solid pieces.
[0008]
Furthermore, since the mixing and stirring pump of the present invention has the functions of stirring and mixing at the same time, the stirring structure and the pump structure can be made very small, and since the rotating shaft is shared, the motor for stirring and mixing is omitted. There is an advantage that the tank and piping for stirring and mixing can be saved and the installation space can be reduced.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Specifically, the stirring and mixing pump of the present invention is attached to a spiral pump main body provided with an impeller that is driven to rotate by a rotary shaft inside the spiral chamber, and to a suction port portion of the spiral pump main body, in the direction of the rotary shaft A long cylindrical casing, a mixed inlet portion provided at the opposite end of the cylindrical casing with respect to the pump main body, to which a mixed fluid is supplied, and an extension portion of the pump main body rotating shaft extended inside the cylindrical casing And a plurality of stirring blades provided around the rotating shaft extension.
[0010]
The cylindrical casing is a vertically long cylindrical tube, and is connected to the suction port portion of the spiral pump main body. The rotary shaft extension is an extension of the rotary shaft of the bump and is inserted into the cylindrical casing. The extension portion is provided with a stirring blade around it, and the stirring blade rotates with the rotation of the pump rotor. Solid pieces and liquid are supplied to the mixing inlet of the casing in a mixed or unmixed state, and the pump main body sucks the solid pieces and liquid into the cylindrical casing along with the rotation of the pump rotor. In the cylindrical casing, the stirring blade flows into the pump body while mixing and stirring the solid piece and the liquid to form a mixed liquid. The mixed liquid that has flowed in is sent to the outlet portion of the pump body by the impeller of the pump rotor, and is fed to the connection pipe.
[0011]
The cylindrical casing is preferably attached to the suction port portion of the centrifugal pump body so as to be replaceable, and the rotary shaft extension portion is preferably attached to the pump rotary shaft so as to be replaceable. Maintenance and inspection of the casing and the rotary shaft extension can be facilitated, and there is an advantage that the rotary shaft extension can be replaced with an appropriate stirring blade corresponding to the shape and properties of the solid piece.
[0012]
The stirring blade can be composed of a large number of paddle blades having a twist for sending the mixed fluid toward the suction port portion of the pump body in the rotation direction. The paddle blades have a small twist angle with respect to the rotation axis direction, project each blade toward the outer periphery around the rotation shaft extension, are spaced apart from each other, and sufficiently act on stirring so that the inner periphery of the cylindrical casing It is preferable to reduce the protrusion height so as to form a flow path between the tip of the paddle blade and the paddle blade tip. Thereby, even if the extension part is directly driven by rotation by the pump rotation shaft having a relatively high rotational speed, while obtaining the stirring and mixing effect, the pump suction port part is prevented from being excessively fed to increase the stirring residence time, Further, cavitation damage at the blade tip can be prevented.
[0013]
Another form of the stirring blade may be formed of a spiral blade having a twist that feeds the mixed fluid toward the suction port portion of the pump body with respect to the rotation direction. The spiral blade reduces the twist angle of the spiral, causes the spiral body to protrude to the outer peripheral side around the rotating shaft extension, and works sufficiently for stirring to flow between the inner periphery of the cylindrical casing and the tip of the spiral blade. It is preferable to reduce the protruding height of the spiral so as to form a path. In this way, even if the rotary shaft extension is directly driven by the pump rotary shaft having a relatively high rotational speed, it is possible to prevent the pump body intake port from being overfed while obtaining the stirring and mixing effect with the spiral blade. Thus, it is possible to increase the stirring residence time of the mixed fluid and to prevent cavitation damage around the blade.
[0014]
Further, the rotary shaft and the rotary shaft extension may be directly connected, but an appropriate speed reducer can be interposed at the joint between the rotary shaft and the rotary shaft extension. May be driven to rotate at a lower speed than the rotational speed of the pump rotating shaft. As such a reduction gear, for example, a planetary gear type reduction gear can be used. By providing a speed reducer, it is possible to effectively prevent the pump main body suction port portion from being excessively fed and to prevent cavitation damage around the blade by using a low speed rotating stirring blade.
[0015]
Preferably, a vertically long bubble separation tube is installed upright and connected to the mixing inlet of the cylindrical casing. The vertically long pipe preferably has an opening to which solid pieces are supplied at the upper end and a fluid inlet to which fluid is supplied at a position below the opening.
[0016]
The vertical pipe keeps the supply opening of the solid piece that causes air inhalation away from the inlet as much as possible to prevent the generation of bubbles harmful to the separation of the solid piece in the subsequent process, and floats upward to separate it can do.
[0017]
In another form, the mixing flow inlet of the cylindrical casing can be directly connected to a receiving tank for receiving solid pieces and fluid and supplying them to the lower inlet. In the case of mixing, the solid piece and the liquid can be directly supplied to the stirring and mixing pump through the receiving tank, and the structure of the stirring and mixing pump can be simplified.
[0018]
The stirring and mixing pump of the present invention can be widely used for mixing a solid piece and a liquid and feeding the mixed liquid. In particular, the solid piece is a plastic piece, and various types of mixed plastic pieces are classified by type. It can be used by being connected to the previous stage of the specific gravity separator for separation. The liquid is selected according to the use of water or other liquid mixture. In the above specific gravity separator, a heavy liquid having an appropriate specific gravity for specific gravity separation can be used according to the type of the mixed plastic piece.
[0019]
【Example】
In the following examples, two or more types of plastic strips as solid pieces and water as a liquid are stirred and mixed.
[0020]
FIG. 1 shows an outline of specific gravity separation equipment. Waste plastic P containing various plastics having different specific gravities is supplied, and is pulverized by a pulverizer 5 into fine plastic strips P2 having a size of about 5 mm square to about 30 mm square. A constant amount is supplied to the mixing and stirring pump by a feeder. This equipment is provided with a specific gravity separation device 20 to separate light plastic LP and heavy plastic HP in waste plastic pieces from the separated plastic by separating sieves 25 and 26. The waste water is drained, and the waste liquid is mixed again with the waste plastic piece and returned to the specific gravity separator 20.
[0021]
The stirring and mixing pump 1 of the embodiment is used for mixing and feeding the liquid W and the plastic piece P2 in which the specific gravity of the waste liquid is adjusted.
The stirring and mixing pump 1 includes a spiral pump body 3 that rotatably supports a rotary shaft 16 including an impeller 1b that is rotationally driven at 100 to 300 RPM via a joint C by a motor M within the spiral chamber 1a. The stirring and mixing unit 10 is attached to the suction port 17 of the pump body via a flange F.
[0022]
The stirring and mixing unit 10 includes a cylindrical casing 11 that is long in the direction of the rotation shaft 16, a mixing inlet 11 a that is provided at an end of the casing 11 opposite to the pump spiral chamber 1 a and to which a mixed fluid is supplied, The pump 11 includes a pump rotation shaft extension 12 extended inside the casing 11 and a plurality of paddle-shaped stirring blades 13 provided around the rotation shaft extension 12.
[0023]
This mixing agitation pump has a structure in which an agitation / mixing tank, which has been separately provided in the past, is integrated into the pump so that piping can be omitted, and the occupied space can be reduced. Therefore, the configuration of stirring and mixing and supply is very compact.
[0024]
The mixed inlet 11a has a top opening 14a to which the plastic strip P2 is supplied at the upper end, and a liquid inlet 14b to which the return water W from the specific gravity adjusting tank 40 is supplied at the top and bottom. A long vertical tube 14 is connected.
[0025]
The vertical tube 14 functions as a bubble separation tube, and sucks the plastic strip P2 supplied in a fixed amount together with the returning water W to maintain a constant mixing ratio, while maintaining a constant mixing rate from the supply top opening 14a of the plastic strip P2. Inhalation of air is suppressed to the minimum to prevent the separation accuracy due to air bubbles from being lowered in the specific gravity separator in the subsequent process.
[0026]
The rotary shaft extension 12 is attached to the pump rotary shaft 13 in a replaceable manner with a screw joint (not shown) and includes a rotary shaft extension having an appropriate stirring blade 13 corresponding to the nature, size, or shape of the solid piece. To be replaced.
[0027]
In this example, paddle stirring blades 13 are used as stirring blades. The paddle blades 13 project each blade around the rotating shaft extension portion toward the outer peripheral side, and send the mixed fluid in the direction of the pump suction port portion 17. A small twist angle is provided with respect to the direction of the rotation axis. Further, a large number of paddle blades 13 are arranged away from each other over the longitudinal direction of the rotary shaft extension 12. The paddle blades sufficiently perform the stirring function and have a small protruding height so as to form a wide flow path between the inner circumference of the cylindrical casing and the tip of the paddle blade.
[0028]
These paddle blades 13 are fed to the pump inlet port 17 while obtaining a sufficient stirring and mixing effect even when the rotary shaft extension 12 is directly rotated by the pump rotary shaft 16 having a relatively high rotational speed. Therefore, it is possible to increase the stirring and residence time of the mixed fluid in the mixing section, and to reduce the flow velocity with respect to the paddle blade 13 to prevent cavitation damage at the blade tip.
[0029]
Although the front side of the rotary shaft extension 12 can be cantilevered, in this example, the front end of the rotary shaft extension 12 is connected to the mixed inlet portion 11a side of the casing via a bearing. It is supported on the end face.
[0030]
FIG. 2 shows a stirring and mixing pump 2 according to another embodiment, which is different from the stirring and stirring pump 1 of FIG. 1 in that the mixing unit 101 is provided with a spiral stirring blade 131 in the rotating shaft extension 121. Yes.
[0031]
The spiral blade 131 is formed in the axial direction by projecting a spiral body around the rotary shaft extension 121 to the outer peripheral side, and a small twist angle of the spiral so as to send the mixed fluid of the pump body 3 toward the suction port 17. The projecting height of the spiral body is reduced so as to sufficiently act on stirring and form a flow path between the inner periphery of the cylindrical casing 11 and the tip of the spiral blade 13.
[0032]
As a result, even if the rotary shaft extension 121 is directly driven by the pump rotary shaft 16 having a relatively high rotational speed, the pump blade suction port 17 is fed while the stirring and mixing effect is obtained by the spiral blade 131. Therefore, it is possible to increase the stirring residence time of the mixed fluid and to prevent cavitation damage around the blade.
[0033]
A receiving tank 141 to which the plastic piece P2 and the fluid W are supplied is connected to the mixed liquid inlet 111a of the casing 11 in this example. The receiving tank 141 is a tank in which a solid piece supply pipe and a water supply pipe are connected in parallel to the upper part, and simultaneously receives the solid piece P2 from the solid piece supply pipe and the water W from the water supply pipe. To the liquid mixture inlet 111a. Such a receiving tank is preferably used particularly in the case of stirring and mixing that is not affected by the generation of bubbles.
[Brief description of the drawings]
FIG. 1 shows a stirring and mixing pump according to an embodiment of the present invention and a specific gravity separation device using the stirring and mixing pump.
FIG. 2 is a schematic cross-sectional view of a stirring and mixing pump according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Stirring mixing pump 1a Centrifugal chamber 1b Impeller 2 Stirring mixing pump 3 Centrifugal pump 10 Mixing part 11 Casing 11a Inlet part 12 Extension part of a pump rotating shaft 13 Stirring blade (paddle blade)
131 stirring blade (spiral blade)
14 Vertical pipe 141 Receiving tank 14a Top opening 14b Liquid inlet 15 Pump 16 Rotating shaft 17 Pump suction port P2 Plastic piece W Water

Claims (4)

A mixing agitation pump 1,101 that mixes and supplies liquid W with fine plastic strips P2 of about 5 mm square to about 30 mm square pulverized from waste plastic P containing various plastics having different specific gravities,
A centrifugal pump 3 main body including an impeller 1b having a large rotation radius that is rotationally driven by a rotary shaft inside the spiral chamber 1a, and sending a mixed flow of the plastic strip P2 and the liquid W;
Rotating shaft direction having a smaller diameter than the spiral chamber 1a, one end attached to the suction port of the spiral pump 3, and the other end provided with a mixed inlet for supplying a mixed flow containing the plastic strip P2 and the liquid W A long cylindrical casing 11, an extension portion of the pump rotating shaft 16 extended inside the cylindrical casing 11, and a plurality of stirring blades 13 and 131 provided around the extending portion of the rotating shaft. A stirring and mixing unit,
The stirring blade is composed of a number of paddle blades 13 or spiral blades 131 having a twist for feeding the mixed fluid toward the suction port portion of the pump body in the rotation direction, and the twist is the suction port portion 17 of the pump body. The tip of the stirring blade forms a flow path between the cylindrical casing 11 and the rotation of the pump. By rotating the shaft at 100 to 300 rpm, the plastic strip P2 and the liquid W are uniformly stirred and mixed by the large number of paddle blades 13 or spiral blades 131 of the stirring and mixing unit, and at the same time, the impeller 1b is placed inside the spiral chamber 1a. The agitated and mixed pump for waste plastic, wherein the mixed flow is sucked from the suction port portion of the pump main body and the mixed flow is sent out from the supply port .  A vertically long tube 14 is erected and connected to the mixed inlet 11a. The vertically long tube 14 has a solid piece opening 14a for supplying solid pieces at the upper end, and a fluid inlet portion 14b for supplying fluid is solid. The stirring and mixing pump according to claim 1, wherein the stirring and mixing pump is located below the one opening 14 a.  The stirring and mixing pump according to claim 1, wherein a tank 141 for receiving solid pieces and fluid is connected to the mixing inlet 111a.  The stirring and mixing pump according to claim 1, wherein the cylindrical casing (11) is detachably attached to the suction port portion of the centrifugal pump body, and the rotating shaft extension (12) is replaceably attached to the pump rotating shaft (16). .

Images