Process pump with dynamic seal for dry run capability

A positive displacement pump comprising:

• a pump housing having an inlet and an outlet, the pump housing having a first side that houses a pumping fluid and a second side isolated from the pumping fluid;
• a fluid pathway arranged between the inlet and the outlet;
• an internal gear assembly arranged along the fluid pathway and configured to suck fluid into the pump housing at the inlet and expel the fluid out of the pump housing at the outlet, wherein the internal gear assembly comprises a shaft extending along an axial direction and having a first end and a second end opposite to the first end, the first end arranged closer to the first side of the pump housing than the second end;
• a first bearing arranged around the shaft and spaced apart from the fluid, wherein the first bearing is a thrust bearing;
• a first sealing element arranged between the first bearing and the internal gear assembly and configured to isolate the fluid from the first bearing, the first sealing element separating the first side of the pump housing from the second side of the pump housing:
• a seal holder plate arranged between, in the axial direction, the first end of the shaft and the first sealing element, the seal holder plate being removable from the pump housing at the first side of the pump housing;
• and
• a seal backing plate operably coupled to the seal holder plate, wherein the seal holder plate is arranged between, in the axial direction, the seal backing plate and the first end of the shaft,
• wherein the first sealing element and the seal holder plate are sized and shaped such that the first sealing element and the seal holder plate are merely accessible and removable from the first side of the pump housing.

A positive displacement pump comprising:

• a pump housing comprising an inlet and an outlet;
• a sealing assembly arranged within the pump housing and arranged between a fluid portion of the pump housing and a packing box portion of the pump housing, the sealing assembly comprising:
• a seal holder plate,
• a seal backing plate operably coupled to the seal holder plate,
• a first sealing element sandwiched between the seal holder plate and the seal backing plate, and
• a second sealing element sandwiched between the seal holder plate and the seal backing plate;
• an internal gear assembly arranged within the fluid portion of the pump housing and configured to pump fluid from the inlet to the outlet, wherein the internal gear assembly comprises a shaft arranged within and extending through the fluid portion of the pump housing and the packing box portion of the pump housing in an axial direction;
• and
• a first bearing concentrically surrounding the shaft in the packing box portion of the pump housing, the first bearing providing axial thrust support for the shaft,
• wherein the sealing assembly concentrically surrounds the shaft and prevents fluid flow from the fluid portion of the pump housing into the packing box portion of the pump housing, the sealing assembly being sized and shaped such that the sealing assembly is merely accessible and removable from the fluid portion of the pump housing.