WO2012006464A2

WO2012006464A2 - Pulsation dampener

Info

Publication number: WO2012006464A2
Application number: PCT/US2011/043250
Authority: WO
Inventors: Douglas Rodenburg; James D. Mcchesney
Original assignee: Ironstone Separations, Inc.
Priority date: 2010-07-07
Filing date: 2011-07-07
Publication date: 2012-01-12
Also published as: WO2012006464A3

Abstract

A liquid pulsation dampening system for preparative chromatography is disclosed. In one implementation, the system effectively dampens liquid pulsation while minimizing holdup volume and maximizing the effective dampening range. The liquid pulsation dampening system comprises disc spring washers (also known as belleville spring washers) which are compressed by liquid pulsation though an inert diaphragm, a liquid pressure transmitter and a piston.

Description

PULSATION DAMPENER

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of United States provisional application no. 61/362,293, filed 7 July 2010, which is hereby incorporated by reference as though fully set forth herein.

BACKGROUND

a. Field

[0002] The present invention relates to an apparatus for dampening pulsating liquid flows in applications such as, but not limited to, preparative liquid chromatography. b. Background

[0003] Liquid Chromatography represents a major technology for analysis and separation of complex mixtures. In the technique a mobile liquid (eluent solvent) is passed through a column of adsorbent such that when samples of the mixture to be separated are introduced, they are carried through the column and separation effected via the differential partitioning of the components of the mixture between the adsorbent surface and the mobile liquid. The

chromatographic system can be suitably scaled for analytical applications (sample injections of micrograms) or preparative separations (sample injections of milligrams to kilograms). The efficiency of the separation can be improved by increase of the adsorbent surface area in the column. This is accomplished by use of porous adsorbent particles and most effectively by reduction in adsorbent particle size. The limitation introduced by adsorbent particle size reduction is the great increase in pumping pressure required to deliver the mobile phase through the small particle packed bed of adsorbent in the column.

[0004] This has resulted in the development of high pressure liquid chromatography (HPLC). In HPLC a chromatographic column is connected by tubing to a pump that operates to deliver the mobile liquid through the column from a reservoir. The most common type of pump is a plunger type and the delivery is accomplished by a reciprocating motion of the plunger. This generates a pulsating pressure and flow of the liquid being delivered in accordance with the reciprocal motion of the plunger. These pressure and flow gradients follow the pumping frequency of the reciprocating plunger of the pump. They can cause detrimental effects for the operation of the HPLC by disturbing the smooth flow of the mobile liquid through the adsorbent bed of the column, by mechanically damaging the bed structure, and by interfering with the recording of data using sensitive detection instruments. A conventional method to reduce or eliminate the pulsations in the pressure and flow is to use a plurality of plungers (2 or more) such that they react with each other to reduce flow fluctuations. This has resulted in a reduction in the pressure and flow fluctuations but not eliminated them. One alternative approach is to insert in the liquid flow path an apparatus for the reduction of pressure and flow pulsations (a Pulse Dampener).

BRIEF SUMMARY

[0005] In one implementation, a liquid chromatography system is provided. The liquid chromatography system comprises a solvent reservoir, a reciprocating pump, a pulse dampener, a chromatographic column, detector(s), and a solvent receiver connected by suitable conduits. The sample can be introduced to the solvent stream and then to the chromatographic column by various mechanisms. In one implementation, the solvent and sample are transported through the chromatographic column for separation of the constituents of the sample. Reciprocating pump types are used to control flow rates at the pressures required, but also produce flow and pressure pulsation by their nature. Pulsations in flow are detrimental to chromatographic performance, detection, and stability of the chromatographic column. In some implementations of a chromatographic system, the solvent flow paths ideally should have minimal internal volume and be well swept to afford uninterrupted flow of the liquid and sample to and through the column. A minimal internal volume of the solvent flow paths, for example, can be important during changes in solvent composition, solvent changeovers or gradient elutions. If excessive internal volume of the solvent flow path is present it can cause mixing which is detrimental to efficient solvent changeover and loss of reproducible time-based solvent proportions during gradient elutions.

[0006] In one particular implementation, a pulse dampener for use in a fluid flow system is provided. In this implementation, the pulse dampener comprises: a base comprising an inlet port, an outlet port, and an interior fluid flow chamber, the inlet port and the outlet port configured to couple the interior fluid flow chamber to the fluid flow system; a diaphragm defining at least a portion of a surface of the interior fluid flow chamber being defined by a diaphragm; and a pulse dampener assembly comprising a piston, at least one resilient member, and a spring guide, wherein the diaphragm is configured to cooperate with the piston to compress the at least one spring within the spring guide under pressure from fluid flow in the interior fluid flow chamber.

[0007] In another implementation, a pulse dampener for use in a fluid flow system is provided. In this implementation, the pulse dampener comprises: a base comprising an inlet port, an outlet port, and an interior fluid flow chamber, the inlet port and the outlet port configured to couple the interior fluid flow chamber to the fluid flow system; a first diaphragm defining at least a portion of a first surface of the interior fluid flow chamber; a second diaphragm defining at least a portion of a second surface of the interior fluid flow chamber; a first dampener assembly comprising a first piston, a first resilient member, and a first resilient member guide, wherein the first diaphragm is configured to cooperate with the first piston to compress the first resilient member within the first resilient member guide under pressure from fluid flow in the interior fluid flow chamber; and a second dampener assembly comprising a second piston, a second resilient member, and a second resilient member guide, wherein the second diaphragm is configured to cooperate with the second piston to compress the second resilient member within the second resilient member guide under pressure from fluid flow in the interior fluid flow chamber.

[0008] In one implementation, a pulsation dampener which overcomes the disadvantages of the previously known pulse dampening apparatuses is provided. A pulse dampener can be sized for practically any chromatography application from consideration of one or more of the size of the reciprocating pump and its delivery volume per stroke, the pressure ranges which are expected, the volume of fluid to be delivered per amount of pressure change and from these considerations, appropriately sizing the diaphragm, piston and springs.

[0009] Although a pulsation dampener is described herein for use in a chromatograph system, the pulsation dampeners described herein may also be used in any number of other fluid flow applications. For example, a pulsation dampener may be used in various fluid (e.g., food or pharmaceutical) processing applications, high purity applications, any fluid flow application in which contaminants or other particles being introduced may be undesirable, or the like. [0010] The foregoing and other aspects, features, details, utilities, and advantages of the present invention will be apparent from reading the following description and claims, and from reviewing the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a cross sectional view of a preferred embodiment of the disc spring pulsation dampener.

[0012] Figure 2 is an expanded cross sectional view of a preferred embodiment of the disc spring pulsation dampener focusing on the base, diaphragms, non-compressible fluid chamber and pistons.

[0013] Figure 3 is pressure recording of the output of a first reciprocating pump without a pulse dampener and with the present invention installed.

[0014] Figure 4 is a pressure recording of the output of a second reciprocating pump without a pulse dampener and with the present invention installed.

DETAILED DESCRIPTION

[0015] Referencing Figures 1 and 2, one implementation of the present invention is illustrated as a pulsation dampener installed as close as possible to the source of pulsations, the reciprocating pump or other pulsation source.

[0016] In the implementation shown in Figures 1 and 2, for example, a disc spring pulsation dampener 28 comprises a square body 1 containing an inlet port 16 and an outlet port 17.

Circular diaphragms 2 and 3 nest into the base 1. Cylindrical bodies 4 and 5 insert into the base and when assembled compress the outer ring on diaphragms 2 and 3 to form seals. Inserted into each body are flanged cylindrical pistons 10 and 11. Piston 10 has a groove 20 for an elastomeric seal and has grooves 22 and 23 for elastomeric piston guides. Piston 11 has a groove 21 for an elastomeric seal and has grooves 24 and 25 for elastomeric piston guides.

[0017] Between the pistons 10 and 11 and the spring guides 8 and 9 provide areas housing for disc spring washer sets 12 and 13. The disc spring washer sets 12 and 13 can be varied in size and sequence to accomplish various loads and deflections. When assembled with bolts 31 threaded into the base 1, the caps 6 and 7 press the spring guides 8 and 9 onto the spring washer sets 12 and 13 preloading the spring washer sets 12 and 13 and seating the piston flanges 10 and 11 against bodies 4 and 5. A non-compressible fluid (e.g., oil) is installed though ports 18 and 19 and fill compression chambers 14 and 15. In some implementations, the non-compressible fluid in the compression chambers 14 and 15 transfer force from the diaphragms 2 and 3 to the pistons 10 and 11, respectively, which in turn each compress at least one resilient member (e.g., a spring such as a spring washer set). In the particular implementation shown in Figures 1 and 2, chambers 26 and 27 are formed simply to reduce the mass of the assembly and serve no other purpose. The chambers 26 and 27, for example, may be otherwise shaped or not be provided depending on the design of a particular pulsation dampener.

[0018] Pulsating fluid from the reciprocating pump flows into the inlet port 16 and between diaphragms 2 and 3 and exits the pulse dampener though outlet port 17. Diaphragm 3, piston 11 and spring washer set 13 comprise the low pressure pulse dampening portion of the assembly. As the fluid pressure exceeds a particular pressure (e.g., a predetermined pressure, such as approximately 107 psi), pulsation dampening begins with diaphragm 3, a non-compressible fluid (e.g., oil) in chamber 15, and piston 11 compressing spring washer set 13. The pulse of fluid is absorbed within the assembly as the diaphragm 3 moves and the spring washers 13 are compressed. As the fluid pulse subsides, the spring washers 13 through the piston 11, the fluid (e.g., oil) in chamber 15 and diaphragm 3 discharge absorbed fluid which maintains fluid flow and pressure at the outlet 17. The low pressure side ceases to dampen fluid pulses when the piston 11 has moved enough to contact the spring guide 9 and eliminate the space 30. In one implementation, for example, the combination of the components of the low pressure side may cease to dampen fluid pulses at about 537 psi, however, as described below the pulsation dampener may be designed to stop at any desired pressure. The stop prevents over deflection and damage to the disc spring washer set 13.

[0019] The high pressure side operates similarly. Diaphragm 2, piston 10 and spring washer set 12 comprise the high pressure pulse dampening portion of the assembly. As the fluid pressure exceeds a particular pressure (e.g., a predetermined pressure, such as approximately 477 psi), pulsation dampening begins with diaphragm 2, a non-compressible fluid (e.g., oil) in chamber 14, and piston 10 compressing spring washer set 12. The pulse of fluid is absorbed within the assembly as the diaphragm 2 moves and the spring washers 12 are compressed. As the fluid pulse subsides, the spring washers 12 through the piston 10, the fluid (e.g., oil) in chamber 14 and diaphragm 2 discharge absorbed fluid which maintains fluid flow and pressure at the outlet 17. The high pressure side ceases to dampen fluid pulses when the piston 10 has moved enough to contact the spring guide 8 and eliminate the space 29. In one implementation, for example, the combination of the components of the high pressure side may cease to dampen fluid pulses at about 1749 psi, however, as described below the pulsation dampener may be designed to stop at any desired pressure. The stop prevents over deflection and damage to the disc spring washer set 12.

[0020] In one particular implementation, the disc spring pulsation dampener 28 provides a limited holdup volume (e.g., volume within a fluid flow chamber disposed between the input port and the output port of the pulse dampener 28). The relatively small holdup volume reduces or even eliminates separate fluid flows (e.g., solvents in a chromatograph implementation) from mixing within the fluid flow chamber. In various example embodiments, for example, the fluid flow chamber may have a holdup volume of approximately less than or equal to 50 mL, less than 25 mL, between 10 an 20 mL, and less than lOmL.

[0021] Although the implementation shown in Figures 1 and 2 describe various shaped or sized components, one of skill in the art would readily recognize that these components need not be so limited, but merely describe the one particular implementation shown in Figures 1 and 2. Thus, while the body 1 of the pulsation dampener is described with relation to Figures 1 and 2 as being a square body, diaphragms 2 and 3 are described as circular diaphragms, bodies 3 and 4 are described as being cylindrical, and any other components are described in the particular implementation as having a particular shape and/or size, the components need not be so limited but rather can vary in size and shape depending on the particular design of a pulsation dampener.

[0022] The pulse dampener can be sized for practically any chromatography application from consideration of the size of the reciprocating pump and its delivery volume per stroke, the pressure ranges which are expected, the volume of fluid to be delivered per amount of pressure change and from these considerations, appropriately sizing, as taught above, the diaphragm, piston and springs.

[0023] In addition, although the implementation shown in Figures 1 and 2 show two pulse dampener assemblies generally opposing each other, a pulse dampener may have a single pulse dampener assembly, two pulse dampener assemblies, or even additional pulse dampener assemblies.

[0024] One or more components of a pulse dampener can be designed and/or selected to achieve various operating conditions for the dampener. The design and/or selection of components of the pulse dampener are briefly described as follows and are illustrated in Figures 1 and 2.

[0025] In one example, the following aspects of the pulse dampener are designed according to needs of a chromatograph. For example, a stroke volume of the pump plunger or diaphragm can be designed. In an implementation shown here, a 7 mL stroke volume is selected.

Similarly, the portion of the stroke volume to be delivered by the pulse dampener can also be designed. In this particular implementation, 50% of the stroke volume is selected (thus, 3.5 mL). A change of pressure during which the 3.5 mL selected above will be delivered by the pulse dampener can also be designed. In this particular implementation, for example, a change of pressure of 100 psi is selected. A range of pressure over which the pulse dampener will function can also be selected. In this example implementation, a range of pressure of 100 to 1500 psi is selected. Various energy absorbing mediums can also be selected for a pulse dampener. In this implementation, for example, disc spring washers are chosen for the energy absorbing medium. A number of loading cycles for energy absorbing medium (in this case, the disc spring washers) can also be designed. In this particular implementation, for example, 2,000,000 cycles is selected. This determines the deflection range for a given disc spring washer. Since a single set of spring washers may not be capable of meeting all the above criteria, a high pressure set and low pressure set of spring washers are employed in this implementation. By trial and error, a combination of piston diameter and disc spring deflection change which will deliver the volume desired, 3.5 mL, during the desired change of pressure, 100 psi, can be selected. For the high pressure, for example, the following components can be selected:

a. a 3 inch diameter piston, 7.06 square inch area, delivers a force of 10,603 lb when 1,500 psi is applied and travels 0.0305 inches to deliver 3.5mL.

b. Christian Bauer disc spring washer number 920 276 01 has a 2M expected cycle life when deflected approximately 15 to 45% of its full deflection and delivers 12,364 lb force or 1749 psi on the 3 inch piston face at approximately 45% deflection for the upper pressure limit.

c. A single series stack of 11 each of these washers with these deflections will move the 3 inch piston the 0.0305 inches needed to deliver 3.5mL over a 100 psi pressure drop. This spring stack is preloaded to approximately 15% of its deflection or 3,372 lb force or 477 psi at the 3 inch piston face for the lower pressure limit of the high pressure side.

For the low pressure side, the following components can be selected:

the operating range is 100 psi to 500 psi for an overlap of dampening, 477 to 500 psi.

a 2 inch diameter piston, 3.14 square inch area, delivers a force of 1,571 lb when 500 psi is applied and travels 0.0685 inches to deliver 3.5mL.

Christian Bauer disc spring washer number 920 201 01 has a 2M expected cycle life when deflected approximately 15 to 45% of its full deflection and delivers 1,686 lb force or 537 psi on the 2 inch piston face at approximately 45% deflection for the upper pressure limit.

A single series stack of 8 each of these washers with these deflections will move the 2 inch piston the 0.0685 inches needed to deliver 3.5mL over a 100 psi pressure drop.

This spring stack is preloaded to approximately 15% of its deflection or 377 lb force or 107 psi at the 2" piston face for the lower pressure limit of the low pressure side.

[0027] In summary, to achieve a nominal 100 psi to 1500 psi range of dampening, a low pressure single series stack and a high pressure single series stack of disc spring washers are used in this particular implementation. The low pressure single series stack of eight each disc spring washers are preloaded by mechanical compression to begin to deflect at 107 psi and are mechanically stopped from further deflection at 537 psi. The total movement over this range of pressure is 0.268 inches. The piston diameter is 2 inches. Total volume adsorbed is 15.4 mL. The high pressure single series stack of 11 each disc spring washers are preloaded by

mechanical compression to begin to deflect at 477 psi and are mechanically stopped from further deflection at 1749 psi. The total movement is 0.303 inches over this range of pressure. The piston diameter is 3 inches. The total volume adsorbed is 45.1 mL. Both stacks of the disc spring washers are dynamic in the pressure range of 477 to 537 psi, providing smooth dampening through the transition from lower pressure stack of disc spring washers to the higher pressure stack of disc spring washers. At maximum pressure of 1749 psi the total volume of fluid adsorbed (held up) in the dampener is 60.5 mL, a relatively small volume when compared to the capacity of this pump which is approximately 550 mL per minute. This represents a fluid volume change rate of the held up volume of greater than 8 volume changes per minute at the maximum held up volume occurring at maximum operating pressure, 1749 psi. The volume change rate increases at lower pressures since the held up volume is less. The high rate of flushing of the held up volume has minimal effects on gradient elutions which is important to reproducible gradient chromatography. Additionally, at less than 107 psi the held up volume is very small estimated at 5 mL, which can be flushed during solvent changes very quickly. The calculated range of pressure dampening is 107 to 1749 psi.

[0028] Other stacking configurations of the disc spring washers may be possible, such as combinations of springs in series and in parallel. The low and high pressure springs can be stacked together forming one spring stack using deflection limiting devices such as mechanical stops or rings. It may be possible to insert the 2 inch piston into the 3 inch piston thus having only one diaphragm acting on 2 pistons which act upon a spring stack comprised of

combinations of disc spring washers.

[0029] For chromatographic applications the material of construction for the process fluid contact is important. In one implementation, for example, PTFE is chosen for its inertness and broad chemical compatibility. The limited elasticity of the PTFE is accounted for in the design of the flexing region or the web of the diaphragm. Importantly, the support of the web under loads is by a non-compressible fluid. Other fluoropolymers such as Kynar ® PVDF or Kalrez® and their derivatives might be considered. The base which also is in contact with the process fluid is a non reactive alloy such as 316 stainless steel, 304 stainless steel, other high nickel alloys such as Monel®, Inconel®, Hastalloy® or others.

[0030] With the above information available, balance of the detailed mechanical design can be performed.

[0031] Another example of working through an example design process of a pulse dampener, which was not fabricated, is as follows:

[0032] The stroke volume of the pump plunger or diaphragm, for this example, is selected as 0.37 mL. The portion of the stroke volume to be delivered by the pulse dampener is selected as 50% or 0.185 mL. The change of pressure during which the 0.185 mL selected above will be delivered by the pulse dampener is a change of pressure of 100 psi. The range of pressure over which the pulse dampener will function is nominally 100 to 1500 psi. Disc spring washers are again chosen for the adsorbing medium. The number of loading cycles for the disc spring washers is 2,000,000 cycles. Again a single set of spring washers are not capable of meeting all the above criteria. A high pressure set and low pressure set of disc spring washers are to be employed. By trial and error, a combination of piston diameter and disc spring deflection change which will deliver the volume desired, 0.185 mL during the desired change of pressure, 100 psi, is selected. For the high pressure side:

a. a 1.5 inch diameter piston, 1.8 square inch area, delivers a force of 2,651 lb when 1,500 psi is applied and travels 0.0064 inches to deliver 0.185 mL. b. Christian Bauer spring washer number 920 254 01 has a 2M expected cycle life when deflected approximately 15 to 45% of its full deflection and delivers 3,260 lb force or 1,845 psi on the 1.5 inch piston face at approximately 45% deflection for the upper pressure limit.

c. A single series stack of 2 each of these washers with these deflections will move the piston the 0.0064 inches needed to deliver 0.185 mL

d. This spring is preloaded to approximately 15% of its deflection or 1,068 lbforce or 604 psi at the 1.5" piston face for the lower pressure limit of the high pressure side.

For the low pressure side:

the operating range is approximately 100 psi to 650 psi for an overlap of dampening, 604 to 650 psi.

a 1.5 inch diameter piston, 1.8 square inch area, delivers a force of 1,149 lb when 650 psi is applied and travels 0.0064 inches to deliver 0.185 mL.

Christian Bauer spring washer number 920 195 01 has a 2M expected cycle life when deflected approximately 15 to 45% of its full deflection and delivers 1,169 lb force or 662 psi on the 1.5 inch piston face at approximately 45% deflection for the upper pressure limit of the low pressure side.

A single series stack of 1 each of this washer with these deflections will move the piston the 0.0064 inches needed to deliver 0.185 mL. e. This spring is preloaded to approximately 15% of its deflection or 225 lb force or 127 psi at the 1.5" piston face for the lower pressure limit of the low pressure side.

[0034] In summary, to achieve a nominal 100 psi to 1500 psi range of dampening, a low pressure single series stack and a high pressure single series stack of spring washers are used. The low pressure single series stack of one disc spring washer is preloaded by mechanical compression to begin to deflect at 127 psi and is mechanically stopped from further deflection at 662 psi. The total movement is 0.0335 inches. The piston diameter is 1.5 inches. The volume adsorbed is 0.97 mL. The high pressure single series stack of 2 each disc spring washers are preloaded by mechanical compression to begin to deflect at 604 psi and are mechanically stopped from further deflection at 1845 psi. The total movement is 0.063 inches. The piston diameter is 1.5 inches. The volume adsorbed is 1.8 mL. For both high and low pressure dampening the total volume of fluid held up is 2.8 mL. Again, this held up volume of 2.8 mL is very small relative to the flow capacity of this pump which is approximately 250 mL per minute. At less than 127 psi the held up volume is estimated to be very small and is very quickly flushed during solvent changes. The calculated range of dampening is 127 to 1,845 psi. Since the piston diameters are the same the low pressure and high pressure disc spring washers can easily be stacked in a single stack with a single diaphragm.

[0035] The assembly of the present invention comprises a base having an inlet port and an outlet port and internal cylindrical curves into which closely seat upper and lower chemically inert diaphragms. There are top and bottom cylindrical bodies which seat onto the base and compress the top and bottom diaphragms circumferencely to form the fluid seals. A flanged piston is inserted into each body and the pistons are sealed with an elastomeric seal. The pistons move axially within their respective body. Each body, piston and diaphragm assembly form a chamber which is filled with a non-compressible fluid such as hydraulic oil. This fluid transfers the pressure from the diaphragm to the pistons and then to the springs which are the pressure absorbing components of the system. Each piston has a flange and the flange is one seat of the stack of disc spring washers. Disc spring washers can sustain large loads in a smaller envelope than helical coiled compression springs. Additionally, disc spring washers can be arranged in different sequences to vary the sustained load and total deflection. The other side of each disc spring washer set is a flanged cylinder where the flange is the other seat for the spring washers and the cylinder is an internal guide for the spring washers. These flanged cylinders are held in place by caps which provide the preloading on the disc spring washer set when bolts are installed attaching the caps to the base from each side. These bolts also hold the assembly together and are threaded into the base from each side. The disc spring washers bias the piston toward the base and through the non-compressible fluid hold the diaphragms in position. The diaphragms nearly touch each other and form the very small volume chamber which is the fluid flow path. Fluid flows into the inlet port, between the diaphragms and out the outlet port. As pressure increases on the system the force on the diaphragms is transferred to the non- compressible fluid, to the pistons which compress the disc spring washers. During the fluid delivery portion of the reciprocating pump stroke, the pulse of fluid is absorbed by the compression of the disc spring washers. When the reciprocating pump is not delivering fluid (retracting), the springs uncompress to deliver fluid downstream maintaining fluid flow and dampening the pressure change. The disc spring washers on each side are sized differently. As shown in Figure 1 the spring washers 12 are larger than the spring washers 13. The combination of these sets of disc spring washers extends the dampening range of the assembly. The non- compressible oil in the chamber formed between the diaphragms, bodies and pistons and is necessary to support the web region of the diaphragms and to provide a region for the diaphragms to flex.

[0036] Figure 3 is pressure recording of the output of a first reciprocating pump without a pulse dampener and with a pulse dampener as shown in Figures 1 and 2 installed. The first reciprocating pump is a duplex piston pump having a displacement of approximately 7 mL for each stroke of each piston. The duplex piston pump is manufactured by Jaeco Inc.

[0037] Figure 4 is a pressure recording of the output of a second reciprocating pump without a pulse dampener and with a pulse dampener as shown in Figures 1 and 2 installed. The second reciprocating pump is a small triplex piston pump used for chromatography having a displacement of less than about 1 mL for each stroke of each piston. The triplex piston pump is manufactured by Scientific Systems Inc. as model number Prep 250.

[0038] As can be seen in Figures 3 and 4, the pulse dampener shown in Figures 1 and 2 significantly dampened the fluid flow from the pumps.

[0039] Although embodiments of this invention have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this invention. All directional references (e.g., upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above, below, vertical, horizontal, clockwise, and counterclockwise) are only used for identification purposes to aid the reader's understanding of the present invention, and do not create limitations, particularly as to the position, orientation, or use of the invention. Joinder references (e.g., attached, coupled, connected, and the like) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. As such, joinder references do not necessarily infer that two elements are directly connected and in fixed relation to each other. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims.

Claims

CLAIMS What is claimed is:

1. A pulse dampener for use in a fluid flow system comprising:

a base comprising an inlet port, an outlet port, and an interior fluid flow chamber, the inlet port and the outlet port configured to couple the interior fluid flow chamber to the fluid flow system;

a diaphragm defining at least a portion of a surface of the interior fluid flow chamber being defined by a diaphragm; and

a pulse dampener assembly comprising a piston, at least one resilient member, and a spring guide, wherein the diaphragm is configured to cooperate with the piston to compress the at least one spring within the spring guide under pressure from fluid flow in the interior fluid flow chamber.

2. The pulse dampener according to claim 1 wherein the diaphragm separates the interior fluid flow chamber from a compression chamber of the pulse dampener assembly.

3. The pulse dampener according to claim 1 wherein the piston comprises a sealed piston.

4. The pulse dampener according to claim 3 wherein the sealed piston comprises a flanged piston.

5. The pulse dampener according to claim 3 wherein the sealed piston comprises a flanged elastomerically sealed piston.

6. The pulse dampener according to claim 1 wherein the resilient member comprises at least one spring.

7. The pulse dampener according to claim 6 wherein the at least one spring comprises at least one belleville disc spring washer.

8. The pulse dampener according to claim 7 wherein a mechanical resistance of the at least one belleville disc spring washer is adjustable by varying one or more of the group comprising a number of washers, a size of washers, and stacks of washers.

9. The pulse dampener according to claim 7 wherein a mechanical stop restricts the compression of the at least one belleville disc spring washer beyond a predetermined compression.

10. The pulse dampener according to claim 6 wherein the at least one spring comprises a plurality of belleville disc spring washers.

11. The pulse dampener according to claim 1 wherein the dampener assembly comprises a mechanical stop to prevent the at least one resilient member from compressing beyond a predetermined distance.

12. The pulse dampener according to claim 1 wherein the diaphragm, piston, and base define a compression chamber of the pulse dampener assembly.

13. The pulse dampener according to claim 12 wherein the compression chamber is filled with a non-compressible fluid.

14. The pulse dampener according to claim 13 wherein the non-compressible fluid comprises oil.

15. The pulse dampener according to claim 1 wherein the base is constructed of a relatively inert metal alloy.

16. The pulse dampener according to claim 15 wherein the relatively inert metal alloy comprises one or more of the group comprising as stainless steel and a nickel alloy.

17. The pulse dampener according to claim 1 wherein the interior fluid flow chamber comprises an internal holdup volume of less than or equal to about 50 mL.

18. The pulse dampener according to claim 1 wherein the interior fluid flow chamber comprises an internal holdup volume of less than or equal to about 25 mL.

19. The pulse dampener according to claim 1 wherein the interior fluid flow chamber comprises an internal holdup volume of between about 10 mL and about 20 mL.

20. The pulse dampener according to claim 1 wherein the interior fluid flow chamber comprises an internal holdup volume of less than or equal to about 10 mL.

21. A pulse dampener for use in a fluid flow system comprising: a base comprising an inlet port, an outlet port, and an interior fluid flow chamber, the inlet port and the outlet port configured to couple the interior fluid flow chamber to the fluid flow system;

a first diaphragm defining at least a portion of a first surface of the interior fluid flow chamber;

a second diaphragm defining at least a portion of a second surface of the interior fluid flow chamber;

a first dampener assembly comprising a first piston, a first resilient member, and a first resilient member guide, wherein the first diaphragm is configured to cooperate with the first piston to compress the first resilient member within the first resilient member guide under pressure from fluid flow in the interior fluid flow chamber; and

a second dampener assembly comprising a second piston, a second resilient member, and a second resilient member guide, wherein the second diaphragm is configured to cooperate with the second piston to compress the second resilient member within the second resilient member guide under pressure from fluid flow in the interior fluid flow chamber.

22. The pulse dampener according to claim 21 wherein the second dampener assembly comprises a relatively lower pressure dampener than the first pressure dampener assembly.

23. The pulse dampener according to claim 22 wherein the first and second dampener assemblies extend a performance range of the pulse dampener.

24. The pulse dampener according to claim 21 wherein the diaphragm separates the interior fluid flow chamber from a compression chamber of the pulse dampener assembly.

25. The pulse dampener according to claim 21 wherein the first piston and second piston each comprise a sealed piston.

26. The pulse dampener according to claim 25 wherein each of the sealed pistons comprises a flanged piston.

27. The pulse dampener according to claim 25 wherein each of the sealed pistons comprises a flanged elastomerically sealed piston.

28. The pulse dampener according to claim 21 wherein each of the first resilient member and the second resilient member comprises at least one spring.

29. The pulse dampener according to claim 28 wherein the at least one spring comprises at least one belleville disc spring washer.

30. The pulse dampener according to claim 29 wherein a mechanical resistance of each of the at least one belleville disc spring washer is adjustable by varying one or more of the group comprising a number of washers, a size of washers, and stacks of washers.

31. The pulse dampener according to claim 29 wherein a mechanical stop restricts the compression of each of the at least one Belleville disc spring washer beyond a predetermined compression.

32. The pulse dampener according to claim 28 wherein the at least one spring comprises a plurality of belleville disc spring washers.

33. The pulse dampener according to claim 21 wherein each of the first dampener assembly and the second dampener assembly comprises a mechanical stop to prevent the first and second resilient members from compressing beyond a predetermined distance.

34. The pulse dampener according to claim 21 wherein the first diaphragm, first piston, and base define a first compression chamber of the pulse dampener assembly.

35. The pulse dampener according to claim 34 wherein the first compression chamber is at least partially filled with a non-compressible fluid.

36. The pulse dampener according to claim 34 wherein the first compression chamber is filled with a non-compressible fluid.

37. The pulse dampener according to claim 36 wherein the non-compressible fluid comprises oil.

38. The pulse dampener according to claim 21 wherein the base is constructed of a relatively inert metal alloy.

39. The pulse dampener according to claim 38 wherein the relatively inert metal alloy comprises one or more of the group comprising as stainless steel, a high nickel alloy, and a nickel alloy.

40. The pulse dampener according to any of the preceding claims further comprising a chromatograph fluid flow system coupled to the inlet and outlet ports of the pulse dampener.

41. The pulse dampener according to any of the preceding claims further comprising a fluid flow system coupled to the inlet and outlet ports of the pulse dampener, wherein the fluid flow system comprises one or more of the group comprising: a food processing fluid flow system, a pharmaceutical fluid flow system, a medical fluid flow system, and a high purity application.

42. The pulse dampener according to claim 21 wherein the interior fluid flow chamber comprises an internal holdup volume of less than or equal to about 50 mL.

43. The pulse dampener according to claim 21 wherein the interior fluid flow chamber comprises an internal holdup volume of less than or equal to about 25 mL.

44. The pulse dampener according to claim 21 wherein the interior fluid flow chamber comprises an internal holdup volume of between about 10 mL and about 20 mL.

45. The pulse dampener according to claim 21 wherein the interior fluid flow chamber comprises an internal holdup volume of less than or equal to about 10 mL.

46. The pulse dampener according to any of the preceding claims wherein the input port of the pulse dampener is coupled to a reciprocating pump and the output port of the pulse dampener is coupled to a chromatographic column.