JP5064070B2 - Peristaltic pump, method of manufacturing a hose therefor, and hose for such a pump - Google Patents

Abstract

A pump for circulating a medium comprises: an elastically deformable hose which lies against a pressing surface, and has a medium inlet and a medium outlet; and pressing elements which move along the hose and press the hose part in contact with a pressing element against the pressing surface while locally compressing and closing the hose part; whereby medium is drawn in via the medium inlet and discharged under pressure via the medium outlet. The pump has the special feature that the pressing surface, the hose and the pressing elements are situated in a bath with lubricant, and that the hose consists solely of a thermoplastic vulcanizate (TPV).

Description

  The present invention relates to a peristaltic pump for circulating a medium such as liquid, gas, slurry, particulates, or a combination of two or more thereof, the pump comprising: a pump chamber; and the pump chamber A pressure surface that is present and an elastically deformable hose, a portion of the hose being placed against the pressure surface, the hose having a media inlet and a media outlet, and a roller or cam And pressurizing means comprising several pressurizing elements arranged at equal intervals, the pressurizing means being drivable so that the pressurizing element moves along the hose, During operation, the pressurizing element locally compresses and closes the hose part while pressing the hose part in contact with the related pressurizing element against a part of the pressurizing surface. During operation of the pressure means, the medium is the medium Drawn through the inlet, and to a peristaltic pump that is discharged through the medium outlet under pressure.

  Such a peristaltic pump is known, for example, from US 2006/0018777.

  Thanks to the local compression, thereby blocking the hose by the pressurizing element, and this local compression movement under the influence of the pressurizing element operating along the hose, the medium present in the hose is along the hose. Pushed out. After the pressurizing element has passed, the hose shape is restored to its original state by the elastic nature of the hose. By this mechanism, the medium is drawn into the suction side of the hose.

  Since the hose is always locally pressurized and closed by at least one locally actuated pressurizing element, the pump appears to be separated from each other on the delivery side and the suction side Acts as a closed valve.

  Within the peristaltic pump, the hose is successively loaded locally as the pressurizing element passes under pressure. This causes fatigue of the hose material. As a result, fatigue cracks that occur after a while may eventually cause the hose to break. As a result, the fed medium and the fed medium flow out of the hose, and in some cases, the lubricant present outside the hose may be mixed with the fed medium. Since the process of crack formation depends on many factors, it is difficult to predict the moment when fracture occurs. Destruction causes the technical breakdown specifically described and results in undesired maintenance at unpredictable times.

  In light of the foregoing, it is an object of the present invention to significantly increase the life of the hose.

  Furthermore, the known types of peristaltic pumps described do not compete much with other displacement pumps. This is because the pumping capacity of the peristaltic pump is relatively small with respect to the capacity of the pump and the cost of the pump. If it is not true that the hose life is significantly shortened by a normal peristaltic pump, it can be considered to increase the capacity by increasing the circulation rate. It is a further object of the present invention to modify known pumps to increase hose life or increase pump capacity by increasing pump circulation rate.

  A pump known from the aforementioned US 2006/0018777 is provided with a layered hose. The inner layer is made of PTFE (polytetrafluoroethylene) that allows the chemical resistance of the hose to reach the desired level. The carrier or casing can be composed of an elastomer having a very large elasticity at various ordinary temperatures, for example a commercially available material named Santoprene. According to this US published patent, the pump hose has the resistance to chemicals of fluororesin material and the elasticity of elastomer that has very large elasticity at room temperature.

  However, a problem that occurs with this well-known hose is that the pump suffers from premature delamination that occurs as a result of strong shear forces that are repeatedly generated due to repeated compression and expansion. is there. This makes the hose unusable in a short time. Because the integrity of the PTFE layer is destroyed and therefore the chemical resistance of the hose becomes determined by the chemical resistance of the carrier material not specifically designed or selected for this purpose. It is. This leaves many demands on the life of this known pump.

  In view of the foregoing, the present invention provides a peristaltic pump of the type described in the preamble. This peristaltic pump is characterized in that a pressurizing means comprising a pressurizing surface, a hose and a pressurizing element is placed in a tank containing a lubricant. The hose consists only of a homogeneous thermoplastic vulcanizate (TPV).

  It is known that US Pat. No. 2,248,619 shows a possible mechanical principle of a smoothed hose pump. In general terms and without going beyond the specification, plastic materials such as natural rubber, synthetic rubber or similar materials suitable for the above medium for circulation are mentioned.

  This publication, in accord with the teachings of the present invention, does not give any indication of the possible direction of a hose consisting solely of a homogeneous thermoplastic vulcanizate. Attention is drawn to the fact that the US patent publication focuses attention on layered hoses. Furthermore, this fact is completely opposite to the important basic principle of the present invention.

  It is also noted that the hose according to the invention is independent of any form of reinforcing agent (for example in the form of a mat) in which fibers with tensile strength are embedded, according to the definition given. For example, these tougheners are well known and conventional per se for hose pumps.

  In a preferred embodiment, the pump is characterized in that the material of the hose is made of ethylene propylene diene rubber (EPDM) and polypropylene (PP).

  In a specific embodiment, the pump is characterized in that the pump is a linear type. “Linear” is understood to mean a pump in which the pressurizing element follows more or less at least one linear path along the pressurization surface, as well as a pressurization surface with more or less at least one linear configuration. Is done.

  Furthermore, a rotary peristaltic pump for circulating the medium, comprising a pump chamber and a curved pressure surface existing in the pump chamber, wherein at least a part of the curved pressure surface is an arc having a central axis. It takes a general form and comprises an elastically deformable hose, a part of the hose being placed against the pressure surface, the hose having a medium inlet and a medium outlet, and a roller or cam A rotor with several pressurizing elements, such that the pressurizing elements are placed radially at equal angles, the rotor can be driven rotationally around a central axis, and the pressurizing The element locally compresses and closes the hose portion during operation while pressing the hose portion in contact with the associated pressure element against a portion of the pressure surface, and pressurizing means During operation, the medium is drawn through the medium inlet. Filled-and peristaltic pump that is discharged through the media exit are known under pressure.

  This pump is particularly important in the context of the present invention. This is because pumps, commonly referred to as “hose pumps”, are so common that the pumps are well suited for conformance with the teachings of the present invention.

  According to the present invention, the rotary peristaltic pump comprises a pressurizing means including the pressurizing surface, the hose and the pressurizing element placed in a tank containing a lubricant, and the hose is a homogeneous thermoplastic vulcanization. It is characterized by consisting only of things (TPV).

  It is noted that according to the present invention, this rotary pump has a structure other than, for example, a linear pump. Nevertheless, the principle realized there is the same. Thereby, the effect taught by the present invention is easily realized in a rotary pump.

  Furthermore, the present invention relates to a method of manufacturing a hose for a particular type of peristaltic pump. According to this method, a granular material made of rubber and thermoplastic plastic is pressurized through an annular extrusion nozzle at an elevated temperature and pressure, and the hose-like extrusion from the extrusion nozzle is cooled. And a hose of a desired length is cut from the extrudate thus obtained.

  According to this method, a “new” material is used, that is, a material that was clearly not used in principle.

  The above-mentioned material selection according to the invention is also suitable, for example, for recycling a hose of the type according to the invention that has already been used. In that regard, the present invention also provides a method of manufacturing a hose for a pump. According to this method, previously manufactured and possibly already used hoses are crushed into granules made of rubber and thermoplastic plastic, which are annular extruded at elevated temperature and pressure. Pressure is applied through the nozzle, the hose-like extrudate exiting the extrusion nozzle is cooled, and the hose of the desired length is disconnected from the extrudate thus obtained.

  The present invention still further relates to a hose intended and embodied for application as a component of a peristaltic pump of the type according to the invention. According to the present invention, this hose is characterized in that the material of the hose is a thermoplastic vulcanizate (TPV).

They currently follow three definitions for purposes of clarity of the present invention.
(1) A thermoplastic vulcanizate or TPV is a thermoplastic elastomer (TPE) composed of a chemically cross-linked rubber phase formed using dynamic vulcanization.
(2) The thermoplastic elastomer or TPE forms part of a family of rubbery materials other than ordinary vulcanized rubber. Thermoplastic elastomers or TPE can be processed and recycled in the same way as thermoplastic materials. Thermoplastic elastomers have performance and properties that are consistent with conventional cured rubber products. However, thermoplastic elastomers can be processed with the speed, efficiency, and economic advantages of thermoplastic materials.
(3) Dynamic vulcanization is a process for dissolving an intimate mixture of a rubber polymer that reacts appropriately with a thermoplastic polymer to obtain a TPE which is a chemically cross-linked rubber phase; The rubber thermoset results in closer properties than the same configuration without cross-linking.

  The invention will be clarified with reference to the sole figure.

  This figure shows a cross section through 1 of a peristaltic pump according to the invention of the rotary type.

Pump 1 is
Pump chamber 2,
With a pressure surface present in this pump chamber 2, the pressure surface has the general form of a semi-cylinder extending up to 180 ° and has a central axis 5,
An elastically deformable hose 4 having a medium inlet and a medium outlet;
A rotor 8 with two pressure cams 9, 10, which are arranged diametrically opposite each other, for example with respect to a central axis 5 which is also the central axis of the rotor 8 at a mutual angle of 180 ° Evenly arranged in relative radial positions. In this embodiment, the pressurization cam is embodied as a partially cylindrical cam with a central axis 11, 12, respectively. The rotor 8 can be rotationally driven around the central axis 5 using drive means (not shown). During operation, the pressure cams 9 and 10 locally compress the hose part while pressing a part of the hose 4 contacting the pressure cams 9 and 10 against a part of the pressure surface 3. Then block. The medium is drawn through the medium inlet 6 during operation of the pressurizing means and discharged through the medium outlet 7 under pressure.

  The sucked medium is indicated by arrow 13. The medium discharged under pressure is indicated by arrow 14.

  The structure of the pump 1 is known per se. The present invention resides in the selection of the material of the hose 3. This material is a thermoplastic vulcanizate (TPV).

  Very suitable materials are ethylene propylene diene rubber (EPDM) and polypropylene (PP). This material has excellent resistance to acids, bases, oxidizing substances, alcohols, aldehydes, and light foodstuffs.

  As another option, the material of the hose is composed of nitrile rubber (NBR) and polypropylene (PP). One example is the registered trademark Geolast of Advanced Elastomer Systems, Belgium. This material is very suitable for the discharge of oil, base and diluted acid.

  As another option, the material of the hose is composed of nitrile rubber (NBR) and polyvinyl chloride (PVC). One example in this regard is Nitrovin, a registered trademark of Vi-Chem Corporation of the United States.

  Furthermore, as another option, it is composed of polyacrylate rubber (ACM) and polyamide (PA). One example in this regard is the registered trademark Zeotherm of Zeon Chemical, USA.

  A liquid lubricant is present in the space 15 arranged in the pump. Very suitable as the action of a liquid, such as a lubricating coolant, is a lubricating coolant named “Bredel Genuine Hose Lubricant” commercially available from the applicant. This is a liquid having a kinematic viscosity coefficient from about 600 mPa · s to about 700 mPa · s at 20 ° C. This lubricating coolant is registered with the United States NSF under the number 123204.

The experiment shows a combination of materials for the hose according to the invention and the peristaltic pump according to the invention. Rotor 8 with pressurization surface 3, hose 4 and pressurization cams 9, 10 was placed in the lubricant and the pump could have a life of 3-7 times longer than described below. .
(1) When an unlubricated pump of the same material is used for the hose and the pressure cams 9 and 10 are replaced with freely rotating rollers.
(2) When other tested materials are used in unlubricated peristaltic pumps with rollers.
(3) For a lubricated peristaltic pump with a fixed cam and normal hose material. The normal hose material is, for example, a rubber hose selectively provided with a reinforcing agent.
(4) When a hose having a strong tendency to delaminate as a result of shearing is employed in the pump according to US Published Patent Application 2004/0018777. Therefore, the pump has a short life.

  Experiments also show that by increasing the rotational speed of the rotor 8, the combination allows for a faster pump flow rate of 3 to 10 times.

  It is noted that the material of the hose is not limited to the examples described above.

1 shows a cross-sectional view through a rotary pump according to the invention.

Claims (15)

A peristaltic pump for the circulation of media such as liquid, gas, slurry, particulates, or a combination of two or more thereof,
The above pump
A pump room,
A pressure surface present in the pump chamber;
An elastically deformable hose, a portion of the hose being placed against the pressure surface, the hose having a medium inlet and a medium outlet;
A pressure means comprising a number of pressure elements arranged at regular intervals, such as rollers or cams,
The pressurizing means can be driven so that the pressurizing element moves along the hose,
The pressurizing element compresses and closes the hose part locally while pressing the hose part in contact with the related pressurizing element against a part of the pressurizing surface during operation,
During the operation of the pressurizing means, the medium is drawn through the medium inlet and is discharged through the medium outlet under pressure,
The pressurizing means comprising the pressurizing surface, the hose and the pressurizing element are placed in a tank containing a lubricant,
A peristaltic pump characterized in that the hose is made of only a homogeneous thermoplastic vulcanizate.   2. The peristaltic pump according to claim 1, wherein the material of the hose includes ethylene propylene diene rubber and polypropylene.   2. The peristaltic pump according to claim 1, wherein the material of the hose includes nitrile rubber and polypropylene.   2. The peristaltic pump according to claim 1, wherein the material of the hose includes nitrile rubber and polyvinyl chloride.   2. The peristaltic pump according to claim 1, wherein the material of the hose includes polyacrylate rubber and polyamide.   The peristaltic pump according to any one of claims 1 to 5, wherein the material of the hose has a hardness in a range of shear A hardness 55 to 95, the dimensions of the hose, and the design height of the medium in the hose. A peristaltic pump, characterized in that it is selected on the condition of pressure and desired chemical resistance. In the peristaltic pump according to any one of claims 1 to 6,
A peristaltic pump characterized in that the pump is a linear type. A rotary peristaltic pump for circulation of a medium according to any one of claims 1 to 6,
A pump room,
A curved pressure surface present in the pump chamber, at least a portion of the curved pressure surface takes the general form of an arc having a central axis;
An elastically deformable hose, a portion of the hose being placed against the pressure surface, the hose having a medium inlet and a medium outlet;
With a rotor with several pressure elements such as rollers or cams, the pressure elements being placed radially at equal angles;
The rotor can be driven to rotate around the central axis,
The pressurizing element compresses and closes the hose part locally during operation while pressing the hose part in contact with the related pressurizing element against a part of the pressurizing surface,
During the operation of the pressurizing means, the medium is drawn through the medium inlet and is discharged through the medium outlet under pressure,
The pressurizing means comprising the pressurizing surface, the hose and the pressurizing element are placed in a tank containing a lubricant,
A peristaltic pump characterized in that the hose is made of only a homogeneous thermoplastic vulcanizate.   9. A method of manufacturing a hose for a peristaltic pump according to any one of claims 1 to 8, wherein the granulate made of rubber and thermoplastic plastic is annularly extruded at an elevated temperature and pressure. A method in which pressure is applied through a nozzle, the hose-like extrudate exiting the extrusion nozzle is cooled, and a hose of a desired length is disconnected from the extrudate thus obtained.   A method for manufacturing a hose for a peristaltic pump according to any one of claims 1 to 8, wherein a previously manufactured hose and possibly already used hose is crushed to produce rubber and thermoplastic A granulate made of plastic is obtained, the granulate is pressurized through an annular extrusion nozzle at an elevated temperature and pressure, the hose-like extrudate exiting the extrusion nozzle is cooled, and thus A hose having a desired length is cut off from the extrudate obtained in step (b). A hose intended and embodied to be applied as a component of a peristaltic pump according to any one of claims 1-8,
The hose is made of a thermoplastic vulcanizate. The hose according to claim 11, wherein the material of the hose includes ethylene propylene diene rubber and polypropylene. 12. The hose according to claim 11, wherein the material of the hose includes nitrile rubber and polypropylene. 12. The hose according to claim 11, wherein the material of the hose includes nitrile rubber and polyvinyl chloride. 12. The hose according to claim 11, wherein the material of the hose includes polyacrylate rubber and polyamide.

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