Pump separating gas from liquid

Abstract

A centrifugal pump separating gases from liquids pumps fluid containing gas comprises a pump housing divided into a working fluid chamber and an empty chamber by a baffle, the empty chamber connected to the working fluid chamber by an opening and connected to a gas separation assembly by a pumping chamber duct; an inlet for drawing liquid into pump, a outlet for pumping liquid outward and a separated gas exhaust port; an electric motor with protective cover drives an impeller cluster to create rotary movement; gas separator has a spring of sufficient hardness to control the gas discharge valve to open and close; this gas separator is connected to the empty chamber by the duct mentioned above and connected to the pump outlet by the bleed hole. During operation, when suction gas reaches a certain amount, reduced pressure at the pump outlet opens the valve to release the gas.

Claims

1. A pump separating gas from liquid comprising: a pump housing defining a space area containing a working fluid, circulating a flow of liquid from a pump inlet on a cover plate to a pump outlet on a frame structure; a motor and driving mechanism comprising an electric motor fixed on the frame structure so that a drive shaft must satisfy concentricity with an inner circumference of the frame structure; an impeller cluster consists of an axial impeller in the shape of two or more spiral blades and a centrifugal impeller in the shape of plural vanes extending from a center to an outside, the axial and centrifugal impellers are mounted in succession on the drive shaft and fixed by bolts and an anti-turn, and the axial impeller are located downsteam the pump inlet; a sealing assembly includes an oil seal, an oil seal plate and a first O-ring, all of which are fixed to the frame structure by a baffle and bolts, wherein the baffle divides the pump housing into an empty chamber and a working fluid chamber; on the baffle there is an opening that creates a flow of liquid and gas into the empty chamber; a gas separator including a valve seat, a spring and a valve body, all of which are fixed to the frame structure by a gas separator cap and bolts sealed by a second O-ring; the gas separator has a gas discharge duct connected to the empty chamber to draw the gas outside the pump and a bleed hole connected to the pump outlet.

2. The pump separating gas from liquid according to claim 1 wherein the motor and driving mechanism is replaced by an internal combustion engine.

3. The pump separating gas from liquid according to claim 1, wherein the gas separator operates in an open state and a closed state: in the open state, the spring will compress and cause the valve seat to move along the valve body into an open position and create a flow from the empty chamber to a gas exhaust port on the gas separator cap; in the closed state, when force is applied to the valve seat, the spring is further compressed until it is strong enough to push the valve seat into a closed position.

4. The pump separating gas from liquid according to claim 1, wherein a position of the opening on the baffle of the seal assembly is located between a center and an inward edge of the frame structure in an opposite direction to gravity.

5. The pump separating gas from liquid according to claim 2, wherein the gas separator operates in an open state and a closed state: in the open state, the spring will compress and cause the valve seat to move along the valve body into an open position and create a flow from the empty chamber to a gas exhaust port on the gas separator cap; in the closed state, when force is applied to the valve seat, the spring is further compressed until it is strong enough to push the valve seat into a closed position.

6. The pump separating gas from liquid according to claim 1 wherein the motor and driving mechanism is replaced by a pneumatic engine.

7. The pump separating gas from liquid according to claim 2, wherein a position of the opening on the baffle of the seal assembly is located between a center and an inward edge of the frame structure in an opposite direction to gravity.

8. The pump separating gas from liquid according to claim 3, wherein a position of the opening on the baffle of the seal assembly is located between the center and an inward edge of the frame structure in an opposite direction to gravity.

9. The pump separating gas from liquid according to claim 1 wherein the motor and driving mechanism comprise an electric motor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1-a: Perspective drawing of components showing centrifugal pump according to the invention;

(2) FIG. 1-b: Perspective drawing of separate parts showing centrifugal pump according to the invention;

(3) FIG. 2-a: Cross-sectional drawing showing the location of assembly of pump components according to the invention;

(4) FIG. 2-b: Cross-sectional drawing showing the open state of a valve;

(5) FIG. 2-c: Cross-sectional drawing showing the closed state of a valve;

(6) FIG. 3-a: Drawing showing pump chamber from the gas separator view;

(7) FIG. 3-b: A-A cross-section drawing of the pump housing showing the position of the duct between the pump chamber and the gas separator, the gap between the gas separator and the pump outlet;

(8) FIG. 4: Perspective drawing of the pump according to the invention in complete assembly state.

DETAILED DESCRIPTION OF THE INVENTION

(9) Refer to FIG. 1-a, the structure of the pump separates gas from liquid or centrifugal pump according to the design including the basic components: Pump housing 100; Motor and driven mechanism 200; Impeller cluster 300; Seal assembly 400; Gas separator 500.

(10) FIG. 1-b shows the separate parts as below:

(11) Pump housing 100 is made up of cover plate 1 and frame structure 12 into a space containing the working fluid for circulating fluid flow from the pump inlet of the cover plate 1 to the pump outlet of the frame structure 12. The two parts are sealed by O-ring 2 to prevent liquid from leaking back out.

(12) Motor and driven mechanism 200 are electric motors 21 that provide the mechanical power through the drive shaft 20, the electric motor 21 is fixed on the frame structure 12 so that the drive shaft 20 must reach a certain concentricity with the inner circumference of the pump chamber, the purpose of this is to satisfy the assembly requirements of the seal assembly. This motor can be replaced by engines similar to internal combustion engines and pneumatic engines but must ensure the necessary power and revolutions.

(13) The impeller cluster includes 300 axial impeller shaped like two or more spiral blade and centrifugal impeller 6 that has many vane shapes extending from the center to the outside. These two impellers are mounted in succession on the drive shaft 20 in FIG. 2-a, the axial impeller 5 is located just behind the pump inlet (cover plate 1) which draws the fluid flow into the pump housing and shrinks large gas concentrated at the pump inlet, both impellers are fixed on the drive shaft 20 based on bolts 3 and anti-turn 4. Impeller material must ensure the request of mechanical strength, chemical corrosion resistance and cavitation erosion resistance such as copper, aluminum or stainless steel alloys.

(14) Seal assembly 400 includes oil seal 9, oil seal plate 10 and O-ring 11, seal assembly is fixed to frame structure 12 by baffle 8 and bolts 7. When the pump operates in the environment such as: chemicals, high temperature pressure, large rotation speed, it is necessary to select the type of oil seal 9 according to the standard of the shape and material of the seal, normally this seal is made from rubber or synthetic polymers. Baffle 8 has a special design that not only fixes the seal assembly, but also divides the pump housing into the empty chamber and the working fluid chamber. On baffle 8, there is an opening for allowing the passing of working fluid and gas into the empty chamber, the position of the opening is located between the center and the outside of the pump chamber in the opposite direction to gravity.

(15) Gas separator 500 is a gas discharge valve consisting of valve seat 14, spring 15 and valve body 16. All parts are sealed by O-ring 13 and 17 and fixed to frame structure 12 by the gas separator cap 18 and bolts 19. This gas separator is connected to the pump outlet by the bleed hole 22 and connected to the empty chamber by the gas discharge vent 23 as referenced in FIG. 3-a and FIG. 3-b. This valve operates in two states of opening and closing. In the open state, the spring 15 is compressed due to the valve seat 14 moving along valve body 16 into the open position as FIG. 2-b then creates a flow from the empty chamber to the gas exhaust port on the gas separator cap 18. This valve closes when there is a force applied on valve seat 14 so that the spring is further compressed until this force is large enough to push valve seat 14 into the closed position as FIG. 2-c.

(16) FIG. 2-a shows the position of correlation between parts when the pump is fully assembled and ready to operate. The pump according to the completed invention will be shaped as referenced in FIG. 4

(17) The gas separation mechanism of the pump according to the present invention is based on the pressure difference between the spaces inside the pump to control the discharge valve to open and close in the case of pumping the liquid containing gas which is described as follows:

(18) When the pump is not operating, this valve is always open due to compression of spring 15.

(19) Under normal operating conditions, the entire liquid without gas enters the pump inlet of cover plate 1, the liquid flows through axial impeller 5 to centrifugal impeller 6. Here, the rotation of motor 21 rotates the impeller cluster causing the entire liquid to rotate. Centrifugal inertial force applied on the fluid will push fluid to the pump outlet to form a continuous flow inside the pump. At rated flow, the pressure at the pump outlet establishes a stable value. This value is greater than the spring compression force 15 causing the valve to remain closed.

(20) There is another flow taking place inside the empty chamber, the rotating fluid will cause unevenly distributed pressure at the liquid areas with different distances from the center of the frame structure 12. For pump in invention, the liquid pressure at the position of the opening is higher than the pressure at the center position, so there is always a flow of liquid flowing from the working liquid chamber through the opening on the baffle 8, moving through the empty chamber and returning to the working liquid chamber. This flow causes the empty space to always be filled with liquid when pumping the liquid without gas.

(21) In the case of a gas containing liquid being drawn into the pump inlet, the gas is minimized by an axial impeller before entering the centrifugal impeller 6 to avoid the case of too large bubbles coming in suddenly and causing the pump to become unstable. Because the pressure distribution at the center of pump chamber is minimal, where small gas accumulate again into a gas-bag. The gas enters the empty space in place of the original liquid. The more the gas in the liquid accumulates the gas-bag until it is time for the volume of working liquid in the pump chamber to drop, resulting in a drop in pressure at the bleed hole 22 of the pump outlet. This opens the spring valve of gas separator. The gas in the empty space run through the gas exhaust port outward, then the gas from the gas-bag will enter the empty chamber according to the position behind the centrifugal impeller.

(22) The liquid flow through the opening in this process plays the role of filling the gas with the liquid that is drawn into the pump, drawing gas into the empty chamber.

(23) This process takes place continuously to separate gas from liquid.

(24) Impact of the Invention

(25) The invention that provides a solution to separate gas from liquid which is currently not available in commercial products. Because of simple structure, the built-in gas separation mechanism on the pump helps to reduce the size and production costs compared to similar role products.

(26) Currently the invention has been successfully tested and applied on fuel systems for jet engines. The invention is also suitable for general fuel systems as well as for systems requiring separation of gases mixed in input fluids such as pulp pumps, chemical pumps.