Patent Application
20170226999
This disclosure relates to positive displacement pumps and more particularly to fluid covers for positive displacement pumps.
Positive displacement pumps discharge a process fluid at a selected flow rate. In a typical positive displacement pump, a fluid displacement member, usually a piston or diaphragm, drives the process fluid through the pump. When the fluid displacement member is drawn in, a suction condition is created in a fluid chamber between a fluid cover and the fluid displacement member, which draws process fluid into a fluid cavity from the inlet manifold. The fluid displacement member then reverses direction and forces the process fluid out of the fluid chamber through the outlet manifold.
After the process fluid has been applied, or when the positive displacement pump is going to be used to apply a different process fluid, the pump must be flushed to remove any residual process fluid remaining in the fluid chamber. The pump is operated in a typical fashion and drives a solvent or other cleaning fluid through the fluid chambers. The pump continues to drive the cleaning fluid through the fluid chambers until the fluid chambers are adequately cleaned. The volume of cleaning fluid required varies depending on the fluid flow paths within the fluid chambers, as areas of low or no fluid velocity allow contaminants to settle within the fluid chambers, thereby requiring additional flushing to ensure that the fluid chambers are adequately flushed.
According to an aspect of the present disclosure, a pump includes a pump drive system, a first fluid displacement member disposed at a first end of the pump drive system, a first fluid cover attached to the first end of the pump drive system and securing the first fluid displacement member between the first end and the first fluid cover, an inlet manifold attached to the first fluid cover, and an outlet manifold attached to the first fluid cover. The first fluid cover includes a first cover body defined by a first inner wall and a first outer wall. The first inner wall and the first fluid displacement member define a first fluid chamber. A first fluid port and a second fluid port extend through the first cover body. The first fluid port includes a first inner orifice extending through the first inner wall and configured to direct a flow through the first inner orifice and into the first fluid chamber at a first oblique angle to the inner wall. The second fluid port includes a second inner orifice extending through the first inner wall and configured to direct a flow through the second inner orifice at a second oblique angle to the first inner wall. The first inner orifice is disposed a first radial distance from a center of the first inner wall and the second inner orifice is disposed at a second radial distance from the center. The inlet manifold is configured to provide a fluid to the first fluid chamber through the first inlet. The outlet manifold is configured to receive the fluid from the fluid chamber through the first outlet.
According to another aspect of the present disclosure, a fluid cover for a pump includes a cover body extending between a convex outer wall and a concave inner wall. A first fluid port extends through the body, and a second fluid port extends through the body. The first fluid port includes a first outer orifice, a first inner orifice extending through the concave inner wall, and a first flow path extending between the first outer orifice and the first inner orifice. The first inner orifice is positioned on the concave inner wall such that a pumped fluid is directed through the first inner orifice at a first oblique angle to the concave inner wall. The second fluid port is disposed opposite the first fluid port and includes a second inner orifice extending through the concave inner wall, a second outer orifice, and a second flow path extending between the second outer orifice and the second inner orifice. The second inner orifice is positioned on the concave inner wall such that the pumped fluid is directed through the second inner orifice at a second oblique angle to the concave inner wall.
According to yet another aspect of the present disclosure, a method of flushing a fluid chamber includes drawing a fluid into a fluid chamber defined between a fluid cover and a fluid displacement member through an inlet orifice, and driving the fluid out of the fluid chamber through a second inner orifice positioned to receive the fluid circulating within the fluid chamber. The inlet orifice is positioned to provide the fluid to the fluid chamber at a first oblique angle relative to an inner wall of the fluid cover, thereby imparting a rotational movement to the fluid entering the fluid chamber. The second inner orifice is positioned on the inner wall to direct the fluid at a second oblique angle relative to the inner wall.
Air valve 20 is connected to drive system 12 and is configured to direct compressed air to drive system 12. Pump shaft 28 extends through drive system 12 and is driven in a reciprocating manner along axis A-A by the compressed air provided by air valve 20. Fluid displacement member 26a is connected to a first end of pump shaft 28. Diaphragm 44a is directly connected to the first end of pump shaft 28, with diaphragm plate 46a disposed between pump shaft 28 and diaphragm 44a. Similar to fluid displacement member 26a, fluid displacement member 26b is connected to a second end of pump shaft 28. Diaphragm 44b is directly connected to the second end of pump shaft 28, with diaphragm plate 46b disposed between pump shaft 28 and diaphragm 44b.
Fluid cover 14a is attached to a first end of drive system 12 by cover fasteners 48a. A peripheral edge of diaphragm 44a is disposed between fluid cover 14a and drive system 12, with fluid cover 14a and drive system 12 securing diaphragm 44a in place. The peripheral edge of diaphragm 44a forms a fluid seal between fluid cover 14a and drive system 12. Diaphragm 44a and inner surface 34a define fluid chamber 50a. Fluid cover 14b is attached to a second end of drive system 12 by cover fasteners 48b. A peripheral edge of diaphragm 44b is disposed between and secured in place by fluid cover 14b and drive system 12. The peripheral edge of diaphragm 44b forms a fluid seal between fluid cover 14b and drive system 12. Diaphragm 44b and inner surface 34b define fluid chamber 50b. It is understood that drive system 12 may be configured to drive pump shaft 28 in any suitable manner, such as pneumatically, electrically, hydraulically, or in any other suitable manner.
Inlet check valve 22a and outlet check valve 24a are disposed in fluid cover 14a. Similarly, inlet check valve 22b and outlet check valve 24b are disposed in fluid cover 14b. While inlet check valves 22a and 22b and outlet check valves 24a and 24b are shown as self-contained cartridges, which include all of the operating components of a check valve within a replaceable cartridge, it is understood that inlet check valve 22a may be of any suitable configuration for allowing flow into fluid chamber 50a from inlet manifold 16a and outlet check valve 24a may be of any suitable configuration for allowing flow out of fluid chamber 50a to outlet manifold 18. For example, fluid cover 14a may be configured to receive the individual components of inlet check valve 22a and outlet check valve 24a, such as a ball and a seat or poppet, without requiring a cartridge, or may include a permanently installed check valve.
First fluid port 38a through cover body 32a between inlet check valve 22a and inner surface 34a. First fluid port 38a extends through inner surface 34a proximate circumferential edge 42a. First fluid port 38a is configured to impart a swirl flow to the pumped fluid entering fluid chamber 50a. To impart the swirl flow, first fluid port 38a is positioned to introduce the pumped fluid to fluid chamber 50a at an oblique angle to diaphragm 44a and inner surface 34a. The oblique angle prevents the pumped fluid from impinging on either diaphragm 44a or inner surface 34a as the pumped fluid enters fluid chamber 50a.
Second fluid port 40a also extends through cover body 32a between outlet check valve 24a and inner surface 34a. Second fluid port 40b similarly extends through cover body 32b between outlet check valve 24b and inner surface 34b. Second fluid port 40a is configured to receive the pumped fluid within fluid chamber 50a and direct the fluid out to outlet manifold 18 through outlet check valve 24a. Second fluid port 40a is configured to impart and maintain a swirl flow throughout the pump cycle, and second fluid port 40a is oriented such that second fluid port 40a extends through inner surface 34a at an oblique angle to inner surface 34a and diaphragm 44a. To ensure that the desired flow characteristics are achieved, second fluid port 40a may be a mirror-image of first fluid port 38a. Second fluid port 40a extends through inner surface 34a proximate circumferential edge 42a, similar to first fluid port 38a. Positioning both first fluid port 38a and second fluid port 40a proximate circumferential edge 42a encourages the swirl flow at the periphery of fluid chamber 50a, where diaphragm 44a and fluid cover 14a meet, thereby enhancing the flush properties when a solvent or other cleaning agent is pumped through fluid chamber 50a. The flush properties are enhanced because the swirl flow maintains a constant fluid velocity in fluid chamber 50a and removes more contaminants in a quicker manner.
First fluid port 38b extends through cover body 32b between inlet check valve 22b and inner surface 34b. Similar to first fluid port 38a, first fluid port 38b is configured to impart a swirl flow to the fluid entering fluid chamber 50b. First fluid port 38b is positioned to introduce the pumped fluid to fluid chamber 50b at an oblique angle to diaphragm 44b and inner surface 34b, and first fluid port 38b extends through inner surface 34b proximate the circumferential edge of inner surface 34b. Second fluid port 40b also extends through cover body 32b between outlet check valve 24b and inner surface 34b. Second fluid port 40b is configured to receive the fluid within fluid chamber 50b and to direct the fluid out to outlet manifold 18 through outlet check valve 24b. Second fluid port 40b extends through inner surface 34b at an oblique angle to diaphragm 44b and inner surface 34b, similar to second fluid port 34a. Second fluid port 40b extends through inner surface 34b proximate the circumferential edge of inner surface 34b. To ensure that the desired flow characteristics are achieved, second fluid port 40b may be a mirror-image of first fluid port 38b.
Inlet manifold 16 is attached to both fluid cover 14a and fluid cover 14b by manifold fasteners 49. Inlet manifold 16 is configured to provide fluid to both fluid chamber 50a, through first fluid port 38a, and fluid chamber 50b, through first fluid port 38b. Outlet manifold 18 is also attached to both fluid cover 14a and fluid cover 14b by manifold fasteners 49. Outlet manifold 18 is configured to receive fluid from both fluid chamber 50a, through second fluid port 40a, and fluid chamber 50b, through second fluid port 40b. Outlet manifold 18 provides the fluid downstream to a downstream application, such as a paint applicator.
It is understood that fluid cover 14a is configured such that pumped fluid may be provided to fluid chamber 50a through either first fluid port 38a or second fluid port 40a, such that either first fluid port 38a or second fluid port 40a may function as the inlet. In such an instance, outlet manifold 18 may be connected to the other of first fluid port 38a or second fluid port 40a, such that either first fluid port 38a or second fluid port 40a function as the outlet. In this way, fluid covers 14a and 14b are reversible such that the inlet may function as the outlet and the outlet may function as the inlet. In addition, having fluid cover 14a and fluid cover 14b be reversible provides a mistake-proofing function, such that fluid cover 14a may be installed on either the first end or the second end of drive system 12 and fluid cover 14b may be installed on the opposite end of drive system 12 from fluid cover 14a.
During operation, compressed air is introduced to drive system 12 through air valve 20 to pump shaft 28. The compressed air causes pump shaft 28 to reciprocate and pump shaft 28 alternatingly drives fluid displacement member 26a to contract and expand fluid chamber 50a, and fluid displacement member 26b to contract and expand fluid chamber 50b. The pumping operation for fluid pumped through fluid chambers 50a and 50b is substantially similar, thus the pumping operation for fluid chamber 50a will be discussed in further detail. During a first stroke, pump shaft 28 drives fluid displacement member 26b into fluid chamber 50b and pump shaft 28 simultaneously pulls fluid displacement member 26a drawing fluid displacement member 26a away from fluid cover 14a, thereby increasing a volume of fluid chamber 50a. Pulling fluid displacement member 26a causes inlet check valve 22a to open and creates a suction condition in fluid chamber 50a, thereby drawing fluid into fluid chamber 50a. After pump shaft 28 completes the first stroke, pump shaft 28 transitions to a second stroke. During the transition, the movement of fluid displacement member 26a is temporarily ceased, but the orientation of first fluid port 38a and second fluid port 40a maintains a swirl flow within fluid chamber 50a during the transition. During the second stroke, pump shaft 28 drives fluid displacement member 26a into fluid chamber 50a, thereby decreasing a volume of fluid chamber 50a. Driving fluid displacement member 26a into fluid chamber 50a causes inlet check valve 22a to close and outlet check valve 24a to open. With outlet check valve 24a open, fluid displacement member 26a drives the fluid out of fluid chamber 50a through second fluid port 40a and downstream through outlet manifold 18.
First fluid port 38a introduces the fluid into fluid chamber 50a at an oblique angle to inner surface 34a and diaphragm 44a, which promotes swirling of the fluid within fluid chamber 50a. In addition, first fluid port 38a is positioned such that the fluid entering fluid chamber 50a through is prevented from impinging on inner surface 34a and diaphragm 44a. Preventing the fluid from impinging on inner surface 34a and diaphragm 44a maintains a desired fluid velocity in fluid chamber 50a, thereby preventing areas of low or no fluid velocity. In addition, first fluid port 38a is positioned proximate circumferential edge 42a. Positioning the first inner orifice proximate circumferential edge 42a encourages swirl flow about a periphery of fluid chamber 50a, thereby providing for quicker, more efficient flushing of fluid chamber 50a when a solvent is pumped to flush fluid chamber 50a.
As the fluid is driven out of fluid chamber 50a during the second stroke, second fluid port 40a receives the fluid from fluid chamber 50a. Second fluid port 40a is positioned at an oblique angle to inner surface 34a and diaphragm 44a. The oblique angle of second fluid port 40a promotes the swirl flow within fluid chamber 50a throughout the pump cycle, including the first stroke, the transition, and the second stroke. For example, unlike an outlet port aligned with an axis of pump shaft 28, which would cause a drop in flow velocity producing undesirable flow characteristics and areas of no flow velocity, positioning second fluid port 30a at the oblique angle, proximate circumferential edge 42a of inner surface 34a promotes the swirl flow and ensures that the flow has desirable characteristics. Positioning second fluid port 40a at the oblique angle and proximate circumferential edge 42a thus eliminates areas of low flow velocity or no flow velocity. In addition, having second fluid port 40a enter through inner surface 34a proximate circumferential edge 42a further encourages the maintenance of the swirl flow about a periphery of the fluid chamber 50a, thereby facilitating the flushing of fluid chamber 50a and preventing residual process fluid from settling in fluid chamber 50a.
Pump 10 is configured to drive a fluid, such as paint, to a downstream application. After applying the fluid, fluid chambers 50a and 50b must be flushed with a solvent or other cleaning fluid before storage or reuse. Flushing fluid chambers 50a and 50b both maintains the useful life of various components of pump 10 and ensures the quality of the next fluid pumped, such as a paint of a different pigment. To flush pump 10, the solvent is pumped through fluid chambers 50a and 50b in the same manner as other pumped fluids, described above. First fluid port 38a imparts a swirl flow on the solvent and prevents the solvent from having low velocity or no velocity when in fluid chamber 50a. The swirl flow of the solvent prevents pumped fluid, such as paint, from settling within fluid chamber 50a. In addition, the constant velocity maintained in fluid chamber 50a prevents solids, such as fillers and additives from the paint, from settling in fluid chamber 50a. Second fluid port 40a is configured to maintain the swirl flow in fluid chamber 50 during the transition and the second stroke. Second fluid port 40a receives the solvent and provides the solvent to outlet manifold 18. Both first fluid port 38a and second fluid port 40a are disposed proximate the circumferential edge 42a of inner surface 34a. Positioning both first fluid port 38a and second fluid port 40a proximate the periphery of inner surface 34 maintains the swirl flow about a periphery of fluid chamber 50a, which is also proximate a periphery of diaphragm 44a. Maintaining the swirl flow proximate a perimeter of diaphragm 44a and fluid chamber 50a facilitate flushing of fluid chamber 50a, thereby reducing both the volume of solvent and the time required to flush fluid chamber 50a.
The configuration of first fluid ports 38a and 38b and second fluid ports 40a and 40b provide significant advantages. Positioning first fluid port 38a and second fluid port 40a at oblique angles to inner surface 34a and diaphragm 44a encourages the rotational flow of solvent and promotes flushing of fluid chambers 50a and 50b, thereby reducing the material cost and the time cost associated with flushing pump 10. In addition, positioning both first fluid port 38a and second fluid port 40a proximate circumferential edge 42a promotes the swirl flow at a periphery of fluid chamber 50a. Promoting the swirl flow at the periphery of fluid chamber 50a provides for quicker, more efficient flushing of fluid chamber 50a. The swirl flow at the periphery of fluid chamber 50a removes paint or other fluid disposed at the interface of diaphragm 44a and fluid cover 14a, which is traditionally the most difficult portion of fluid chamber 50a to flush. Having a quicker, more efficient flush reduces both the volume of solvent required and the downtime required for flushing. Reducing the volume of solvent required reduces the material costs associated with pump 10a. In addition, reducing the downtime required to clean pump 10 increases the return on investment for pump 10. Furthermore, fluid covers 14a and 14b being interchangeable provides a cost savings to the end user, as the end user requires a single replacement fluid cover in the event either fluid cover 14a or fluid cover 14b requires replacement.
Cover body 32a extends between inner surface 34a and outer surface 36a (shown in
First fluid port 38a extends through cover body 32a between first check housing 52a and inner surface 34a. First flow path 60a extends between first outer orifice 58a and first inner orifice 56a. First outer orifice 58a opens to first check housing 52a, and first inner orifice 56a opens through inner surface 34a of fluid cover 14a. First inner orifice 56a is disposed proximate circumferential edge 42a of inner surface 34a at a radial distance R1 from point A.
Second fluid port 40a extends through cover body 32a between second check housing 54a and inner surface 34a. Second flow path 66a extends between second outer orifice 64a and second inner orifice 62a. Second outer orifice 64a is open to second check housing 54a, and second inner orifice 62a opens through inner surface 34a of fluid cover 14a. Similar to first inner orifice 56a, second inner orifice 62a is disposed proximate circumferential edge 42a of inner surface 34a. Second inner orifice 62a is disposed at a radial distance R2 from point A. Radial distance R1 is approximately equal to radial distance R2, and both R1 and R2 are preferably greater than half of the radial distance between point A and circumferential edge 42a. It is understood that first inner orifice 58a and second inner orifice 62a may be positioned at any desired location on inner surface 34a to provide fluid to fluid chamber 50a tangential to circumferential edge 42a and at an oblique angle to inner surface 34a. For example, first inner orifice 56a may be disposed approximately adjacent second inner orifice 62a, may be disposed opposite second inner orifice 62a, or may be disposed at any other angle of displacement relative to second inner orifice 62a.
During a first stroke of a pump, such as pump 10 (shown in
After completing the first stroke, the pump transitions to a second stroke, in which the fluid is driven downstream from the fluid chamber. During the transition from the first stroke to the second stroke, the pump momentarily stops moving, such that the diaphragm is neither expanding nor contracting the volume of the fluid chamber. During the transition, the positioning of second inner orifice 62a and first inner orifice 56a ensure that the rotational flow of the fluid is maintained within the fluid chamber. Second inner orifice 62a is positioned on inner surface 34a at an oblique angle to inner surface 34a, similar to first inner orifice 56a. In addition, second inner orifice 62a is positioned on inner surface 34a at radial distance R2, which is approximately equal to radial distance R1, such that second inner orifice 62a and first inner orifice 56a are disposed at approximately the same radial distance from point A. Positioning first inner orifice 56a and second inner orifice 62a at approximately the same radial distance from point A ensures that the swirl flow imparted on the fluid by first inner orifice 56a is maintained throughout the pump cycle.
During the second stroke, the diaphragm is driven into the fluid chamber, thereby reducing the volume of the fluid chamber and driving the fluid downstream through second fluid port 40a and outlet check valve 24a. The orientation of second inner orifice 62a relative to inner surface 34a facilitates the removal of fluid and any contaminants carried by the fluid from the fluid chamber. The orientation of second inner orifice 62a also encourages the swirl flow to continue throughout the second stroke. Ensuring that the rotational flow continues throughout the pump cycle prevents solids from settling in the fluid chamber; as such, the position on first inner orifice 56a and second inner orifice 62a enhances the flow characteristics within the fluid chamber.
Cover body 32a extends between inner surface 34a and outer surface 36a (shown in
First fluid port 38a provides a fluid to fluid chamber 50a. First inner orifice 56a is positioned to provide a flow of fluid into fluid chamber 50a at an oblique angle to inner surface 34a, such that a swirl flow is imparted to the fluid entering fluid chamber 50a. First inner orifice 56a is positioned proximate circumferential edge 42a of inner surface 34a. Positioning first inner orifice 56a proximate circumferential edge 42a encourages the swirl flow proximate circumferential edge 42a. First inner orifice 56a is thus positioned to purge any solids residing proximate circumferential edge 42a. While the rotational flow facilitates the purge of fluid chamber 50a, the rotational flow also actively prevents solids from settling anywhere within fluid chamber 50a by ensuring that the fluid within fluid chamber 50a is constantly flowing within fluid chamber 50a throughout the entire pump cycle, regardless of whether the pump is pumping a fluid for application, such as a paint, or a cleaning fluid, such as a solvent.
Similar to first inner orifice 56a, second inner orifice 62a positioned at an oblique angle to inner surface 34a. Second inner orifice 62a is configured such that the swirl flow of the fluid in fluid chamber 50a is maintained throughout the pump cycle. In addition, second inner orifice 62a is disposed on inner surface 34a at radial distance R2, which is preferably approximately equal to radial distance R1. Positioning first inner orifice 56a and second inner orifice 62a at approximately equal radial distances from point A encourages the rotational flow of the fluid in fluid chamber 50a throughout the pump cycle, such that no areas of low velocity or no velocity form within fluid chamber 50a. For example, unlike an outlet orifice aligned with axis A-A of pump shaft 28 (shown in
In
First inner orifice 56a is configured to impart a rotational flow to the fluid exiting first inner orifice 56a into fluid chamber 50a. First flow path 60a extends between first outer orifice 58a and first inner orifice 56a and enhances the flow characteristics of the fluid entering fluid chamber 50a by imparting swirl to the flow of the fluid entering fluid chamber 50a. First flow path 60a may extend helically between first inner orifice 56a and first outer orifice 58a, such that first flow path 60a may impart additional rotational flow to the fluid. It is understood, however, that first flow path 60a may take any suitable configuration for supplying fluid between first outer orifice 58a and first inner orifice 56a, such as a direct path, a curved path, or any other desired configuration. First fluid port 38a and second fluid port 40a produce significant advantages. First fluid port 38a introduces fluid to the fluid chamber 50a in a manner that produces rotational movement of the fluid within fluid chamber 50a. The swirl flow of the fluid within fluid chamber 50a enhances cleaning of the pump when a solvent or other cleaning solution is pumped through fluid chamber 50a. As stated above, second fluid port 40a is preferably a mirror-image of first fluid port 38a. Second fluid port 40a similarly enhances the cleaning of the pump as the orientation of second fluid port 40a encourages swirl flow throughout the pump cycle.
The orientation and positioning of first fluid port 38a and second fluid port 40a enhances the flow of fluid through fluid chamber 50a, thereby enhancing residue removal from fluid chamber 50a. First fluid port 38a and second fluid port 40a ensure a constant, fast fluid velocity throughout fluid chamber 50a. In addition, first fluid port 38a and second fluid port 40a promote flow at a perimeter of inner surface 34a, thereby enhancing flushing of the perimeter, which is typically the most difficult portion of fluid chamber 50a to flush. The oblique angle of first inner orifice 56a promotes swirling of the fluid within fluid chamber 50a and prevents the fluid from striking inner surface 34a, which would cause the fluid velocity to slow. The oblique angle of second inner orifice 62 further promotes swirling by encouraging the rotational flow throughout the pump cycle, including the first stroke, the transition, and the second stroke.
By introducing a swirl flow to fluid chamber 50a, and by maintaining the swirl flow throughout the pump cycle, first fluid port 38a and second fluid port 40a reduce the volume of flushing material required to flush fluid chamber 50a and provide for faster flush time. Using less flushing material reduces the material cost associated with flushing the fluid chamber. The faster flush time decreases the downtime of pump required for flushing, allowing for more efficient, effective use of the pump.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
This application claims priority to U.S. Provisional Application No. 62/193,241 filed on Jul. 16, 2015, and entitled “FLUSHABLE DIAPHRAGM PUMP FLUID CHAMBER,” the disclosure of which is incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62193241 | Jul 2015 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US2016/042096 | Jul 2016 | US |
| Child | 15490692 | US |
