US20110180172A1

US20110180172A1 - High pressure, high flow rate tubing assembly for a positive displacement pump

Info

Publication number: US20110180172A1
Application number: US13/011,822
Authority: US
Inventors: Robert Gledhill, III; John Nguyen
Original assignee: Blu White Ind Inc
Current assignee: Blu White Ind Inc; Blue White Industries Ltd
Priority date: 2010-01-22
Filing date: 2011-01-21
Publication date: 2011-07-28
Also published as: US9828984B2; US20180298891A1; US20150198153A1

Abstract

A tubing assembly is provided that can comprise a plurality of tubes or lumens that can be disposed within a head of a peristaltic pump. The tubing assembly can provide a flow rate or volume capacity that is generally equal to or greater than that achieved with a comparable prior art tube while operating at higher pressures than that possible using the prior art tube. Further, in accordance with some embodiments, the tubing assembly can achieve a longer working life than a comparable prior art tube, and the load on the pump motor can be reduced such that the pump life is increased and/or a larger pump motor is not required to achieve such advantageous results.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/297,710, filed Jan. 22, 2010, the entirety of which is incorporated herein by reference.

BACKGROUND

1. Field of the Inventions
The present inventions relate to tubing assemblies, and more specifically to tubing assemblies for use with peristaltic pumps.
2. Description of the Related Art
A peristaltic roller pump typically has two or more rollers, but may have other configurations. The rollers are generally spaced circumferentially evenly apart and are mounted on a rotating carrier that moves the rollers in a circle. A length of flexible tubing may be placed between the rollers and a semi-circular wall. In medical and lab applications, the tubing can be a relatively soft and pliable rubber tubing. For relatively high-pressure industrial applications, however, the tubing can be exceedingly durable and rigid, albeit flexible under the high pressure of the rollers.
In use, the rollers rotate in a circular movement and compress the tubing against the wall, squeezing the fluid through the tubing ahead of the rollers. The rollers are configured to almost completely occlude the tubing, and operate essentially as a positive displacement pump, each passage of a roller through the semicircle pumps the entire volume of the fluid contained in the tubing segment between the rollers.
As a positive displacement pump, relatively high positive pressures can be generated at the pump outlet. Peristaltic roller pumps are typically driven by a constant speed motor that draws fluid at a substantially constant rate.

SUMMARY

The present inventions relate to pumps and tubing assemblies that are configured to pump fluids at high pressures and high flow rates. More particularly, the tubing assemblies can comprise multiple small diameter tubes that replace the traditional single large diameter hose in peristaltic pumps. In particular, embodiments disclosed herein can enable pumping against high pressures while providing a high flow rate, increased tube life, increased drive efficiency, lower replacement cost, lower energy consumption, cooler operating temperatures, and reduced operating and maintenance costs. All of these advantages are achieved while implementing designs that contrast with the traditional industry standard and knowledge.
In many facilities, typical water pressures can range from 60 to 85 PSI. Most municipalities prefer chemical pumps that can exceed system pressure by at least 20%. Some traditional peristaltic “tube” pumps (which use a single conduit having a diameter of less than 1 inch, referred to as a “tube”) meet the requirements of some water treatment facilities that have small to medium chemical injection demands. However, system pressures and chemical flow rates often exceed the capabilities of existing peristaltic “tube” pumps. Consequently, operators must use larger peristaltic “hose” pumps (which, in contrast to peristaltic “tube” pumps, use a single conduit with a diameter of at least 1 inch or more, referred to as a “hose” because it is larger than a “tube”). Peristaltic hose pumps are considerably more expensive to operate (often three times more) because they use large, high-torque, high-horsepower AC drives.
Although peristaltic pumps have gained widespread popularity, the effectiveness of current peristaltic pumps is severely limited by the design of the tube or hose. The present Applicants spent considerable time and resources researching and redesigning large tubes and hoses for use in high pressure, high flow rate applications. The general rule in industry has always been that the larger diameter of the tube or hose, the higher the pump flow rate (or output). Further, high-pressure industrial peristaltic pumps typically require durable, stiff tubing in order to withstand high pressures. However, using a large diameter tube or hose at high pressure also requires a larger wall thickness in order to withstand the high pressure and avoid “ballooning.” Tubing in a peristaltic pump tends to expand or balloon at the outlet side where system pressure is exerted, and the effects of the ballooning and relaxing of the tubing can build up over time. As the tube size increases in diameter (in order to increase flow rate), the ballooning effect becomes more prevalent. In order to overcome the ballooning problem, the wall thickness of the tubing must be increased, which in turn, causes more resistance to the pumping unit, adding more load to the pump drive unit. These challenges only increase as the required operating pressure is increased. Accordingly, the industry solution prior to the development of the present inventions was to provide a pump with a very powerful motor that can rotate the rollers over a single large diameter, large wall thickness, stiff tube or hose and deliver fluid at high pressures.
In contrast to prior art techniques and applications, some embodiments disclosed herein reflect the realization that instead of using a single large diameter, large wall thickness, stiff tube or hose in a peristaltic pump, high pressures and high flow rates can be achieved with a peristaltic tube pump that uses a system of two or more tubes in which each tube has a smaller diameter and a specific relationship between tube wall thickness and tube durometer. As a result, the pump motor can be much smaller and more efficient than the traditional counterpart peristaltic hose pump that uses a large, stiff tube with a large wall thickness. Moreover, some embodiments are capable of pumping at high pressures and high flow rates while also resulting in increased tube life, increased drive efficiency, lower replacement cost, lower energy consumption, cooler operating temperatures, and reduced operating and maintenance costs. Further, embodiments disclosed herein can deliver fluid at pressures and flow rates that well exceed industry demands. For example, some embodiments can deliver fluid at pressures at or well above 100 PSI while achieving the industry-required flow rates.
Accordingly, some embodiments reflect realizations that in contrast to prior art peristaltic pumps and systems that use a single larger, stiff tube, a peristaltic pump and system using multiple smaller tubes can handle higher pressures, have a longer tube life than a single larger tube, have better memory retention than a single larger tube, and be more energy efficient than a single larger tube. Thus, while the industry has sought to increase fluid output by increasing the size of the tube and increasing the RPM of the motor, some embodiments disclosed herein reflect a contrary view and achieve superior results by using multiple tubes with smaller diameters.
For example, some embodiments disclosed herein reflect the realization that due to the continual cycles of compression and relaxation produced by each pass of the rotating cam, larger diameter tubes (hoses) flatten out sooner, causing a lower flow rate after a short amount of time. Some embodiments disclosed herein also reflect the realization that the ballooning effect can be minimized by using smaller tubes, and that a pump can generally overcome this phenomenon without challenges. Furthermore, some embodiments reflect the realization that smaller tubes tend to retain original memory for an extended amount of time (much longer than a larger diameter tube), resulting in higher accuracy and longer tube life. Moreover, some embodiments reflect the realization that unlike traditional small diameter tubing (which has not been used in high-pressure applications and have a low pressure rating), embodiments can be provided in which a small diameter tube has a desired tube wall thickness and/or desired tube durometer, and/or a desired ratio of tube wall thickness to tube durometer.
Further, some embodiments disclosed herein reflect the realization that there are various potential hazards associated with running a peristaltic pump with large diameter tubing (hose). For example, as noted above, having a large wall thickness to achieve high pressures can cause additional load to the pump drive. Tube diameter expansion (ballooning) can occur on pressure side of pump, which can require additional pump drive load to overcome tube diameter expansion (ballooning) and may result in early tube rupture. In pumps having a glycerin-filled pump head (which is used to reduce friction and heat), tube rupture can cause glycerin to enter the fluid path and contaminate the system.
Therefore, in accordance with an embodiment, a tubing assembly is provided that can comprise an elongate body. The elongate body can define a longitudinal axis, a first end, and a second end. The elongate body can have two or more lumens extending along the longitudinal axis. Each lumen can be surrounded by a tube wall. The lumens can be formed with the tube wall as a monolithic assembly. However, the lumens can also be formed separately from each other with separate tube walls. The plurality of lumens can extend from the first end to the second end such that the first end is in fluid communication with the second end of the elongate body. The first end of the elongate body can be coupled with a first tubing connector of the peristaltic pump. The second end of the elongate body can be coupled with a second tubing connector of the peristaltic pump. Further, the tubing assembly can be inserted into a pump head of the peristaltic pump such that a rotor of the peristaltic pump can operate against the tubing assembly for pumping fluid through the tubing assembly.
The tubing assembly can be configured such that the tubing assembly comprises two or more lumens or tubes. The tubing assembly can also be configured such that the tubing assembly comprises three or more lumens or tubes. Additionally, the tubing assembly can be configured such that the tubing assembly comprises a pair of lumens or tubes that are fused together. Furthermore, the tubing assembly can be configured such that the tubing assembly comprises three tubes that are fused together. Moreover, the tubing assembly can be configured such that the tubing assembly comprises a plurality of tubes that are interconnected by a coupling. For example, the coupling can extend between a given pair of tubes of the plurality of tubes.
Additionally, some embodiments can provide for a tubing assembly for a peristaltic pump that comprises an elongate body. The elongate body can define a longitudinal axis, a first end, and a second end. The elongate body can have a plurality of tubes extending along the longitudinal axis. Each tube can define an inside diameter and be surrounded by a tube wall defining a wall thickness. A ratio of the inside diameter of the tubes to the wall thickness can be within a range of about 0.25 to about 0.45. Each of the plurality of tubes of the elongate body can define a durometer within a range of about 70 to about 90. The plurality of tubes can extend from the first end to the second end such that the first end is in fluid communication with the second end of the elongate body. Further, the tubing assembly can be positionable relative to the peristaltic pump to be operated against for pumping fluid through the tubing assembly.
In some embodiments, the ratio of the inside diameter of the tubes to the wall thickness can be about 0.30. Further, the ratio of the inside diameter of the tubes to the wall thickness can also be about 0.45. The durometer of each of the plurality of tubes can be about 80. Furthermore, the inside diameter of the tubes can be between about ¾″ to about 1″. The assembly can comprise a plurality of tubes, and in some embodiments, can comprise a pair of tubes.
In accordance with some embodiments, a tubing assembly can be provided for a peristaltic pump which comprises a pair of tubes that can be interconnected along their longitudinal extent. The tubes can each define an inside diameter and be surrounded by a tube wall defining a wall thickness. The pair of tubes of the tubing assembly can be positionable in a pump head of the peristaltic pump to be operated against for pumping fluid through the tubing assembly. Further, a ratio of the inside diameter of the tubes to the wall thickness can be within a range of about 0.30 to about 0.45. Furthermore, the tubes can define a durometer within a range of about 70 to about 90. However, the durometer of each of the plurality of tubes can also be about 80. In some embodiments, the inside diameter of the tubes can be between about ¾″ to about 1″.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features of illustrative embodiments of the inventions are described below with reference to the drawings. The illustrated embodiments are intended to illustrate, but not to limit, the inventions. The drawings contain the following figures:

FIG. 1 is a perspective view of a prior art peristaltic pump.

FIG. 2 is a cross-sectional view of tubing of the prior art peristaltic pump shown in FIG. 1.

FIG. 3 is a cross-sectional view of a tubing assembly, according to an embodiment disclosed herein.

FIG. 4 is a cross-sectional view of a tubing assembly, according to another embodiment disclosed herein.

FIG. 5 illustrates the interaction of rollers in a peristaltic pump head when operating against prior art tubing.

FIG. 6 illustrates the interaction of rollers in a peristaltic pump head when operating against a tubing assembly according to an embodiment disclosed herein.

FIGS. 7-14 illustrate cross-sectional views of various tubing assemblies, according to embodiments disclosed herein.

FIG. 15 illustrates a tubing assembly and connectors for a peristaltic pump, according to an embodiment.

FIG. 16 illustrates a peristaltic pump having a tubing assembly formed in accordance with the principles disclosed herein, according to an embodiment.

FIG. 17 illustrates a peristaltic pump and tubing assembly in accordance with an embodiment.

DETAILED DESCRIPTION

While the present description sets forth specific details of various embodiments, it will be appreciated that the description is illustrative only and should not be construed in any way as limiting. Furthermore, various applications of such embodiments and modifications thereto, which may occur to those who are skilled in the art, are also encompassed by the general concepts described herein.
As noted above, embodiments of the present inventions can overcome several prior art deficiencies and provide advantageous results. Some embodiments provide for a peristaltic pump that can operate at high pressures while maintaining a high flow rate. Some embodiments therefore allow the peristaltic pump to operate effectively at higher pressures and flow rates without requiring that the pump have a larger motor. Further, some embodiments can comprise a tubing assembly that can operate at high pressures and flow rates without requiring a larger wall thickness. Furthermore, some embodiments can comprise a tubing assembly that utilizes multiple lumens that are acted upon by one or more rollers to achieve a high flow rate at high pumping pressures.
FIG. 1 illustrates a prior art peristaltic pump 10 that uses a single tube 20, which is shown in cross-section in FIG. 2. As discussed above, one of the problems associated with a single tube arrangement in a peristaltic pump is that the pressure and flow rate are limited. For example, if the pressure is to be increased, the wall thickness of the tubing must also be increased, which creates additional stress on the pump drive. Further, if the flow rate is to be increased, the inner diameter of the tubing and/or the roller RPM must also be increased, which can result in shorter tubing life and higher stress on the pump drive. Therefore, in order to increase both the pressure and flow rate, the tubing life is generally decreased while tubing failure and pump stress is increased. Therefore, at least one of the embodiments disclosed herein reflects that an increased pressure and/or flow rate has only been possible by sacrificing tubing life or increasing the size of the motor of the peristaltic pump.
FIGS. 3-4 illustrate embodiments of a tubing assembly fabricated in accordance with principles of the inventions disclosed herein. For example, FIG. 3 illustrates a tubing assembly 30 having a pair of lumens 32. FIG. 4 similarly illustrates a tubing assembly 50 having a plurality of lumens 52. Further, the tubing assembly can be configured to comprise four or more lumens.
The lumens of tubing assembly can extend along a longitudinal direction of the tubing assembly. In this regard, the tubing assembly can comprise a first end and a second end. The lumens of the tube assembly can extend intermediate the first end and the second end such that the first end and the second end are in fluid communication with each other.
Further, each of the lumens can be surrounded by a wall structure. In some embodiments, the lumens can be surrounded by a wall structure having a generally constant thickness. In other embodiments, the lumens can be surrounded by a wall structure having a variable thickness. However, in some embodiments, the wall thickness and inner diameter of the tube can be generally constant along the length of the tube.
Some embodiments reflect the realization that high pressures and high flow rates can be achieved in a peristaltic tube pump by using a system of one, two, or more small tubes. In some embodiments, multiple tubes can be used to replace a single tube in order to allow for pumping higher volumes at higher pressures. The tubes in such an arrangement can each be uniquely configured to provide desired strength and durometer characteristics. Through substantial testing and analysis, the Applicants have discovered excellent pressure, tube life, and flow characteristics using the measurements, ranges, and tubing characteristics disclosed herein.
For example, in some embodiments, the inside diameter of a tube can be within a range of at least about 1/16″ (1.59 mm) and/or less than or equal to about 3″ (76.2 mm). The inside diameter of a tube in some embodiments can be at least about ⅛″ (3.18 mm) and/or less than or equal to about 1.5″ (25.4 mm). Further, in some embodiments, the inside diameter of a tube can be at least about ½″ (12.7 mm) and/or less than or equal to about 1″ (25.4 mm). For some larger capacity applications, the inside diameter of a tube can be about ¾″ (19.1 mm). For some smaller capacity applications, the inside diameter of a tube can be about ⅜″ (9.5 mm). Two or more tubes can be used together in a tubing application. Thus, a tubing assembly can be provided in which two or more tubes having an inside diameter within the ranges or at the dimensions listed above.
Further, embodiments are provided in which the tube wall thickness is within a range of at least about 1/32″ (0.80 mm) and/or less than or equal to about 1″ (25.4 mm). In some embodiments, the tube wall thickness can be within a range of at least about 1/16″ (1.59 mm) and/or less than or equal to about ½″ (12.7 mm). In some embodiments, the tube wall thickness can be within a range of at least about ⅛″ (3.18 mm) and/or less than or equal to about 5/16″ (7.94 mm). In some larger applications, the tube wall thickness can be about 9/32″ (7.14 mm). In smaller applications, the tube wall thickness can be about 3/16″ (4.76 mm).
Additionally, some embodiments reflect the realization that high pressures and high flow rates can be achieved in a peristaltic tube pump by using a system of one, two, or more tubes in which each tube has a specific relationship between the inner diameter, tube wall thickness, and/or the durometer of the tube. In embodiments using more than one tube, the tubes can be identical. However, the tubes can have different dimensions; for example, the tubes can vary in inner diameter, tube wall thickness, and/or tube durometer. Additionally, as the tube wall thickness increases, the horsepower of the motor must also increase.
In some embodiments, the tube can be configured to have a ratio of tube wall thickness to tubing inner diameter of at least about 20% (0.2:1) and/or less than or equal to about 125% (1.25:1). In some embodiments, the ratio of the tube wall thickness to the inside diameter of a tube can be at least about 20% (0.2:1) and/or less than or equal to about 60% (0.6:1). In some embodiments, the tube can be configured to have a ratio of tube wall thickness to tubing inner diameter of at least about 25% (0.25:1) and/or less than or equal to about 50% (0.50:1). In some embodiments, the ratio of the tube wall thickness to the inside diameter of a tube can be at least about 25% (0.25:1) and/or less than or equal to about 45% (0.45:1). Further, in some embodiments, the ratio of the tube wall thickness to the inside diameter of a tube can be at least about 27% (0.27:1) and/or less than or equal to about 43% (0.43:1). It has been found in some embodiments that excellent pumping qualities and results are achieved when the ratio of tube wall thickness to the inside diameter of a tube is about 28% (0.28:1).
For example, in some embodiments, the inside diameter of a tube can be at least about 1/16″ (1.59 mm) and/or less than or equal to about 2″ (50.8 mm), and the tube wall thickness of the tube can be at least about 1/32″ (0.80 mm) and/or less than or equal to about ⅝″ (15.9 mm). Further, in some embodiments, the inside diameter of a tube can be at least about ⅜″ (9.53 mm) and/or less than or equal to about 1.5″ (38.1 mm), and the tube wall thickness of the tube can be at least about ⅛″ (3.175 mm) and/or less than or equal to about ½″ (12.7 mm). In some larger applications, the inside diameter of a tube can be about 1″ (25.4 mm), and the tube wall thickness of the tube can be about 5/16″ (7.94 mm). In other applications, the inside diameter of a tube can be about ¾″ (19.1 mm), and the tube wall thickness of the tube can be about 7/32″ (5.56 mm). One, two, three, four, or more tubes having such dimensions can be used in a peristaltic tube pump.
In some embodiments, the durometer of a tube can be within the Shore A hardness, within a range of at least about 70 and/or less than or equal to about 90. In some embodiments, the durometer of a tube can be at least about 75 and/or less than or equal to about 90. Further, the durometer of a tube can be at least about 80 and/or less than or equal to about 90. The durometer of a tube can be at least about 83 and/or less than or equal to about 90. Furthermore, the durometer of a tube can be at least about 85 and/or less than or equal to about 89. Durometer values within the above-noted ranges can be implemented for a tube having an inner diameter and/or thickness within any of the above-noted ranges for those parameters. For example, a tube can have inside diameter of at least about 1/16″ (1.59 mm) and/or less than or equal to about ½″ (12.7 mm), a tube wall thickness of at least about 3/32″ (2.38 mm) and/or less than or equal to about 3/16″ (4.76 mm), and a durometer of at least about 75 and/or less than or equal to about 90.
In their studies, Applicants have found excellent test results when comparing multi-tube tubing assemblies to single tube tubing assemblies having approximately equivalent flow rates. In particular, when compared to similar single tube tubing assemblies, multi-tube tubing assemblies provide a much higher tube life before tube failure and experience minimal variance or drop-off in flow rate during the life of the tube.
For example, Applicants have discovered that a dual tubing assembly having tubes with a ⅜″ inside diameter, a durometer of 80, and a tube wall thickness of between about 0.095″ to about 0.10″, tested with water at 30 PSI and 125 RPM, resulted in tube life of 1072 hours until failure. At these dimensions, the ratios of the wall thickness to the inside diameter is about 26%. Further, at 30 PSI and 125 RPM, the dual tubing assembly had a flow rate drop of only 1.25% over the life of the tube (indicative of superior tubing memory characteristics). In particular, the flow rate at start-up was about 7580 ml/min and the flow rate about 24 hours prior to tube failure was 7485 ml/min.
In contrast, a single ½″ inside diameter tube and a tube wall thickness of about 0.125″, was tested with water at 30 PSI and 125 RPM and resulted in a tube life of only 344 hours until failure. Further, at 30 PSI and 125 RPM, the single tube had a flow rate drop of 21.4% over the life of the tube (indicative of poor tube memory characteristics). In particular, the flow rate at start-up was about 6900 ml/min and the flow rate about 24 hours prior to tube failure was about 5420 ml/min.
In further contrast, a single ¾″ inside diameter tube and a tube wall thickness of about 0.125″, was tested with water at 30 PSI and 125 RPM and resulted in a tube life of only 270 hours until failure. Further, at 30 PSI and 125 RPM, the single tube had a flow rate drop of 19.1% over the life of the tube (indicative of poor tube memory characteristics). In particular, the flow rate at start-up was about 9043 ml/min and the flow rate about 24 hours prior to tube failure was about 7316 ml/min.
Accordingly, based on these results, embodiments of a multi-tube tubing assembly can provide far superior tube life and maintain higher flow rates with minimal flow rate reduction over the life of the tubing assembly when compared with a single, larger inside diameter tube that provides approximately the same flow rate as the multi-tube tubing assembly. In this regard, a tubing assembly of two ⅜″ inside diameter tubes would provide higher tube life and lower variance than a comparable 9/16″ inside diameter single tube assembly. Further, other benefits are achieved including decreased loads that enable the use of a smaller pump, easier handling, and increased longevity and efficiency in an operation. Applicants also note that in the field of high pressure, high flow rate pumping, the loss of viable tube life and decrease in flow rate are longstanding problems with single tube designs and have been unresolved until the introduction of embodiments disclosed herein.
In some embodiments, Applicants have also found that the use of a multi-tube tubing assembly achieves higher flow rates than single tube assemblies due to an increased tubing length. For example, a ⅜″ inside diameter dual tube assembly can have a 18⅛″ length as compared to a ½″ inside diameter or ¾″ diameter single tube assembly that has a 17¾″ length. The 18⅛″ length of tubing advantageously provides improved flow rates as opposed to the 17¾″ length. Accordingly, some multi-tube embodiments can provide additional advantages over single tube assemblies.
A desirable ratio of tube wall thickness to the tube durometer can beneficially enable the tubing to have an optimal size and performance. Some embodiments can be configured such that the wall thickness of the tube can be inversely related the durometer of the tube. The thickness and durometer can be modified to provide various benefits, such as enabling the use of a pump motor that is much smaller and more efficient than the traditional counterpart pump required for a peristaltic hose pump. Moreover, some embodiments are capable of pumping at high pressures (exceeding 100 to 125 PSI) and high flow rates while also resulting in increased tube life, increased drive efficiency, lower replacement cost, lower energy consumption, cooler operating temperatures, reduced operating and maintenance costs, and reduced shipping costs.
The lumens of the tubing assembly can also be coupled or joined within the tubing assembly using a variety of manufacturing techniques. In some embodiments, the tubing assembly can be extruded and therefore comprise a monolithic part. Some embodiments can comprise two or more separate parts. For example, some embodiments can be configured such that the tubing assembly 30 comprises one or more tubes that are fused together at a joint. Such an embodiment is shown in FIGS. 3 and 4. Additionally, some embodiments can be configured such that the tubing assembly comprises a plurality of tubes that are coupled to each other via an intermediate coupling or attachment portion.
Moreover, some embodiments can be configured to comprise a plurality of individual tubes. For example, a plurality of individual tubes can be disposed side-by-side within the pump head or cavity of the peristaltic pump.
In addition, when the tubing assemblies of 30, 50 are compared to the tubing assembly 20, the volume capacity of the tubing assemblies 30, 50 can be the same as the tubing assembly 20. For example, the flow area or cross-sectional area as defined by the inner diameter of the lumens of the tubing assemblies 30, 50 can be equal to the flow area or cross-sectional area as defined by the inner diameter of the lumen of the tubing assembly 20. Other advantages may also be present which enable the volume capacity of the tubing assemblies to be equivalent as well.
For example, the rotations per minute (RPM) or drive speed of the roller assembly may be higher when the tubing assemblies 30, 50 are used because of the lower rolling resistance and loading on the pump motor. Thus, it is possible to use tubing assemblies having a flow area that is smaller than a comparable prior art tube while maintaining a common volume capacity or flow rate. Indeed, the volume capacity or flow rate of a given embodiment can be greater than the volume capacity or flow rate of a prior art tube that has a larger flow area than that of the given embodiment. An additional benefit of embodiments disclosed herein is that the volume capacity or flow rate of an embodiment can be equal to the volume capacity or flow rate of a prior art tube while reducing the load on the pump motor. In this manner, embodiments disclosed herein can advantageously increase tubing life and pump motor life.
FIG. 5 illustrates a prior art peristaltic pump 100 in which the tubing 102 is a larger size in order to provide for a higher flow rate. The rollers of the peristaltic pump operate against the tubing 102 and create a large depression in the tubing 102 as the tubing 102 is compressed against the interior wall of the pump head or pump cavity. As a result, the rollers encounter greater resistance and overall, the peristaltic pump is subjected to high loads with the tubing 102 being compressed and deformed against the roller.
Additionally, as the pump 100 operates at high pressures, the tubing 102 can be subject to significant internal pressures which can result in ballooning and/or rupture of the tubing 102. This unfortunate result is due at least in part to the wall thickness of the tubing 102 and the inner diameter of the tubing 102. Therefore, if the wall thickness of the tubing 102 is not increased, the tubing 102 may be subject to failure at high pressures. However, if the wall thickness of the tubing 102 is increased, the rollers of the pump will encounter a greater resistance in compressing the tubing 102 and therefore result in an increased load for the peristaltic pump 100.
FIG. 6 illustrates a peristaltic pump 120 and tubing 122 formed in accordance with an embodiment disclosed herein. Although shown in side view, the tubing 122 comprises a plurality of lumens, similar to one of the embodiments illustrated above in FIGS. 3-4. As will be discussed further herein, the tubing 122 can also be representative of another embodiment, such as one of the embodiments illustrated in FIGS. 7-14.
As shown, the tubing 122 is comparatively much smaller in outer diameter than the tubing 102 illustrated in FIG. 5. Thus, the tubing 122 can be configured to provide an appropriate wall thickness to inner diameter ratio while having a compression radius that is much smaller than the compression radius of the tubing 102. A “compression radius” can be considered as the amount of radial deflection of the tubing as measured relative to the axis of rotation of the roller assembly of the pump. The compression radius of the tubing 102 is illustrated as being much less than the compression radius of the tubing 122. Such a factor is relevant in computing rolling resistance of the roller assembly of the pump, which relates to the load on the pump in order to cause rotation of the roller assembly. Accordingly, when compared with the pump 100 and the tubing 102, the rollers of the peristaltic pump 120 will generally undergo a lower degree of rolling resistance while compressing against the tubing 122, thus decreasing the load on the pump 120.
FIGS. 7-14 illustrate various embodiments of tubing assemblies formed in accordance with the principles and teachings herein. FIG. 7 illustrates a tubing assembly 200 similar to the tubing assembly shown in FIG. 3.
FIG. 8 illustrates a tubing assembly 220 having a plurality of lumens 222 through which fluid can pass. The tubing assembly 220 of FIG. 8 can be configured such that the lumens 222 are spaced apart from each other by a void, hollow portion, or lumen. The lumens 222 can each be disposed in a tube that is separated from an adjacent to by the void or lumen. The tubes can be interconnected via one or more couplings or attachment portions 224. The couplings or attachment portions 224 can extend along the entire length of the tubing assembly 220. Alternatively, the couplings or attachment portions 224 can have a longitudinal length that is less than the longitudinal length of the tubing assembly 220. In such an embodiment, the couplings or attachment portions 224 can be disposed at a plurality of longitudinal positions along the length of the tubing assembly 220.
Further, the couplings or attachment portions 224 can be separate from and later attached to the tubes or formed monolithically with the tubes in an extrusion process. For example, the middle tube of the tubing assembly 220 can be formed monolithically with the couplings or attachment portions 224 such that the overall thickness or width of the tubing assembly 220 as measured at the middle tube thereof does not exceed the outer diameter of the middle tube thereof.
Furthermore, the couplings or attachment portions 224 can extend generally tangentially relative to the tubes of the tubing assembly so as to connect upper and lower points of the tubes to each other. The dimension and the coupling of the couplings or attachment portions 224 can therefore be accomplished along the entire length of the assembly, along only a portion of the length of the tubing assembly, at one or more locations or positions along the tubing assembly, and/or integrated with one or more tubes of the tubing assembly. In this manner, the tubing assembly can therefore be configured generally in the shape of a ribbon of tubes.
FIG. 9 illustrates a tubing assembly 240 having a plurality of tubes defining interior lumens. The tubes of the tubing assembly 240 can be coupled to each other by one or more couplings or attachment portions that extend intermediate the tubes. In particular, FIG. 9 illustrates that a single length of a coupling or attachment portion extends between a given pair of tubes. As noted above, the longitudinal dimension or length of the couplings or attachment portions can be equal to the longitudinal length of the tubing assembly or less than a longitudinal length of the tubing assembly. Further, in some embodiments, the couplings or attachment portions can be disposed at one or more positions along the length of the tubing assembly.
FIG. 10 illustrates a tubing assembly 260 comprising a plurality of tubes that each defines an interior lumen. In this embodiment, the tubes can be generally unconstrained or detached from each other. In particular, the tubing assembly can be devoid of any interconnections between the tubes. As such, the tubes can flex during compression without being physically constrained relative to each other.
As discussed above, each of the tubes of a tubing assembly can define a wall thickness. The wall thickness of a given tube can be different from the wall thickness of another tube of the tubing assembly. For example, one or more of the tubes of a tubing assembly can have an inner diameter, outer diameter, and/or wall thickness that is different from another of the tubes of the tubing assembly.
In addition, in embodiments that utilize a coupling or attachment portion, the ratio of the thicknesses of the coupling or attachment portion relative to the wall of the tube can be at least about 1:1 and/or less than or equal to about 1:3. In some embodiments, the ratio of the thicknesses can be about 1:2.
FIGS. 11-14 illustrate two-tube embodiments corresponding to the three-tube embodiments illustrated and discussed above in FIGS. 7-10. As shown, the embodiments in FIGS. 11-14 include a pair of tubes or lumens instead of three tubes or lumens. Nevertheless, the principles and features discussed above with respect to the tubing assemblies 200, 220, 240, 260 shown in FIGS. 7-10 can also be applied to the embodiments of the tubing assemblies 270, 272, 274, and 276 shown in FIGS. 11-14. Accordingly, the above discussion is incorporated herein with respect to FIGS. 11-14, but will not be repeated. In accordance with the embodiments disclosed herein, a high flow rate can be obtained at high pressure.
FIG. 15 illustrates a tubing assembly 400 that can be coupled with first and second tubing connectors 402, 404. Once the tubing assembly 400 is coupled to the first and second tubing connectors 402, 404, the tubing assembly 400 can be installed into a peristaltic pump. Although the tubing assembly 400 is illustrated as comprising three lumens or tubes, the assembly 400 can comprise two, four, or more lumens or tubes. Further, the assembly 400 illustrates the use of a single inlet and a single outlet. Thus, in some embodiments, a single inlet and single fluid source can be split into a plurality of lumens or tubes in a tubing assembly, pumped through the pump head, and then rejoined through a single outlet. However, as shown in subsequent FIGS. 16-17 below, multiple pump sources can be used to feed lumens or tubes of a tubing assembly.
FIGS. 16-17 illustrate peristaltic pumps that utilize a tubing assembly according to an embodiment disclosed herein. As shown in FIG. 16, the peristaltic pump 450 can be retrofitted with a tubing assembly 452 of one of the embodiments disclosed herein without modifying the pump head or rollers. Thus, existing peristaltic pumps can beneficially use embodiments of the tubing assembly disclosed herein. However, the peristaltic pump can also be modified such that the pump cavity is deeper or wider in order to receive an embodiment of the tubing assembly's disclosed herein.
The tubing assembly of embodiments disclosed herein can comprise a plurality of lumens or tubes that are operatively connected to one or more fluid inlets and one or more fluid outlets. In this regard, as shown in FIG. 15, a plurality of tubes or lumens can be operatively connected to a single inlet and a single outlet. However, in some embodiments, as illustrated in FIG. 17, a peristaltic pump 500 can operate on a tubing assembly 510 in which an inlet of one or more of the tubes or lumens of the tubing assembly 510 is coupled to a first fluid source 520 and an inlet of another one or more tubes or lumens of the tubing assembly 510 is coupled to a second fluid source 522. Thus, the tubing assembly 510 can operate with one or more working fluids passing through one or more tubes or lumens thereof. The multiple fluid sources can be joined to a single outlet; however, multiple outlets can also be used that correspond to the multiple inlets and the fluids can be maintained separate.
Embodiments of the tubing assemblies disclosed herein can be fabricated using a variety of materials, such as polymer materials, rubber, polyurethane, neoprene, tygothane, and others. Further, the tubing assemblies can be fabricated as a composite of multiple materials, or monolithically or uniformly using a single material.
Although embodiments of these inventions have been disclosed in the context of certain examples, it will be understood by those skilled in the art that the present inventions extend beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the inventions and obvious modifications and equivalents thereof. In addition, while several variations of the inventions have been shown and described in detail, other modifications, which are within the scope of these inventions, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the embodiments may be made and still fall within the scope of the inventions. It should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the disclosed inventions.

Claims

1. A tubing assembly for a peristaltic pump, the tubing assembly comprising:

an elongate body defining a longitudinal axis, a first end, and a second end, the elongate body having a plurality of lumens extending along the longitudinal axis, each lumen being surrounded by a tube wall, the plurality of lumens extending from the first end to the second end such that the first end is in fluid communication with the second end of the elongate body, the first end of the elongate body being configured to be coupled with a first tubing connector of the peristaltic pump, the second end of the elongate body being configured to be coupled with a second tubing connector of the peristaltic pump;

wherein the tubing assembly is configured to be inserted into a pump head of the peristaltic pump such that a rotor of the peristaltic pump can operate against the tubing assembly for pumping fluid through the tubing assembly.

2. The tubing assembly of claim 1, wherein the tubing assembly comprises three lumens.

3. The tubing assembly of claim 1, wherein the tubing assembly comprises two lumens.

4. The tubing assembly of claim 1, wherein the tubing assembly comprises a pair of tubes that are fused together.

5. The tubing assembly of claim 1, wherein the tubing assembly comprises three tubes that are fused together.

6. The tubing assembly of claim 1, wherein the tubing assembly comprises a plurality of tubes that are interconnected by a coupling.

7. The tubing assembly of claim 6, wherein the coupling extends between a given pair of tubes of the plurality of tubes.

8. A tubing assembly for a peristaltic pump, the tubing assembly comprising:

an elongate body defining a longitudinal axis, a first end, and a second end, the elongate body having a plurality of tubes extending along the longitudinal axis, each tube defining an inside diameter and being surrounded by a tube wall defining a wall thickness, a ratio of the inside diameter of the tubes to the wall thickness being within a range of about 0.25 to about 0.45, each of the plurality of tubes of the elongate body defining a durometer within a range of about 70 to about 90, the plurality of tubes extending from the first end to the second end such that the first end is in fluid communication with the second end of the elongate body, wherein the tubing assembly is positionable relative to the peristaltic pump to be operated against for pumping fluid through the tubing assembly.

9. The tubing assembly of claim 8, wherein the ratio of the inside diameter of the tubes to the wall thickness is about 0.30.

10. The tubing assembly of claim 8, wherein the ratio of the inside diameter of the tubes to the wall thickness is about 0.45.

11. The tubing assembly of claim 9 or 10, wherein the durometer of each of the plurality of tubes is about 80.

12. The tubing assembly of claim 11, wherein the inside diameter of the tubes is between about ¾″ to about 1″.

13. The tubing assembly of claim 8, wherein the tubing assembly comprises a pair of tubes.

14. A tubing assembly for a peristaltic pump, the tubing assembly comprising:

a pair of tubes being interconnected along their longitudinal extent, the tubes each defining an inside diameter and being surrounded by a tube wall defining a wall thickness, the pair of tubes of the tubing assembly being positionable in a pump head of the peristaltic pump to be operated against for pumping fluid through the tubing assembly,

wherein a ratio of the inside diameter of the tubes to the wall thickness being within a range of about 0.30 to about 0.45, and

wherein the tubes define a durometer within a range of about 70 to about 90.

15. The tubing assembly of claim 14, wherein the durometer of each of the plurality of tubes is about 80.

16. The tubing assembly of claim 15, wherein the inside diameter of the tubes is between about ¾″ to about 1″.