FIELD
The present disclosure relates to positive displacement pumps, and in particular, to a safety deflector for the drive system of a linear frac pump.
BACKGROUND
Existing frac pumps use a chevron-style “packing seal” on a plunger to create a robust seal against the frac fluid or media being pumped at pressures of approximately 15,000-20,000 PSI. This frac media may be composed of water, sand, gel, acid, cement, and other chemicals typically used in well servicing and completion. This media is extremely harsh and even more so at the extreme pressures needed for fracking operations. Therefore, the plunger packing seal has a limited life that may expire during the service pumping operation while under high pressure. Upon failure of the packing seal, high-pressure streams of the harsh frac fluid would escape, with the potential to cause considerable damage to the pump.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an embodiment of a linear pump according to the teachings of the present disclosure;
FIG. 2 is a cross-sectional view of an embodiment of a linear pump according to the teachings of the present disclosure;
FIG. 3 is a more detailed partial cut-away view of an embodiment of the linear pump incorporating a drive system safety deflector according to the teachings of the present disclosure; and
FIG. 4 is a more detailed partial cross-sectional view of the linear pump incorporating a drive system safety deflector according to the teachings of the present disclosure.
DETAILED DESCRIPTION
A plunger packing seal may fail during service pumping operations. When this failure occurs, the high-pressure frac fluid escapes past the plunger. On traditional frac pumps the jet stream of fluid may impact the power end of the pump and potentially damage the pump. In a linear pump configuration, where the fluid end and the drive system are in linear alignment, the risk of damage to the power end due to a failure of the packing seal is even higher. The present disclosure describes a novel deflector structure situated between the fluid end and the drive system of the linear pump that eliminates a direct pathway for the jet stream of frac fluid to enter the drive system. In this way, even in the event of a packing seal failure at high pressure, the drive system is protected.
In a double-action linear pump configuration 10 shown in FIGS. 1 and 2, the drive system 12 is disposed between two fluid ends 14 and 15. The drive system 12 actuates a plunger 16 with two ends that move the frac fluid in both fluid ends 14 and 15. The drive system 12 may be powered by natural gas electric generators, such as gas turbine generators and other types of generators, and an electric motor that powers a hydraulic system that drives the plunger. The fluid ends 14 and 15 each includes two or more valves 18 and 19, functioning as suction valve and discharge valve, that allow the frac fluid to be pumped in and out of the fluid end block by the linear actuation of the plunger.
Referring to FIGS. 3 and 4, an adapter 20 is disposed at an interface between each fluid end and the drive system 12 (referring to fluid end 14 as shown but also applicable to fluid end 15). The adapter 20 is secured to both the drive system 12 and the fluid end 14 at an interface therebetween. The linear pump configuration 10 shown in FIGS. 1 and 2 includes an adapter 20 at both ends of the drive system 12 serving as the interface between the drive system 12 and the fluid ends 14 and 15. The adaptor 20 houses a deflector 22 that is situated within a void 24 within the adapter 20 that is open to the atmosphere outside of the pump 10. With reference also to FIG. 4, the deflector 22 incorporates an angled conical surface 30 that would function to deflect jets of fluid if high-pressure frac fluids escape past the packing seal 32 in the fluid end 14 toward the drive system 12. The angled conical surface 30 of the deflector 22 encircles the plunger 16 and is tapered away from the packing seal 32. The deflector 22 maintains close contact with the plunger 16 so that there is not a gap that would allow fluids to travel between the plunger 16 and the deflector 22 and reach the drive system 12. The angled conical surface 30 of the deflector 22 may be shaped to include one or more concave features to improve the sealing characteristics of the deflector 22 in the event of a packing seal failure. The deflected fluid spray is directed by the angled surface of the deflector 22 out of the adapter 20 and vented to the atmosphere. The deflector 22 may be fabricated of any suitable elastomer and/or metal materials.
It should be noted that although the illustrations herein show a double-action pump configuration, the deflector is equally applicable to a single action pump with a single fluid end.
The features of the present invention which are believed to be novel are set forth below with particularity in the appended claims. However, modifications, variations, and changes to the exemplary embodiments described above will be apparent to those skilled in the art, and the drive system safety deflector for a linear pump described herein thus encompasses such modifications, variations, and changes and are not limited to the specific embodiments described herein.
Patent Application
20230142942
