Penberthy Jet Pumps (Eductors/Ejectors)
medium head, and
high head Penberthy Gas/Steam Motive and Liquid Motive Jet Pumps
(Eductors/Ejectors) in Bronze, Cast Iron, Carbon Steel (CS), Stainless
Steel (SS), Monel, Hastelloy, PVC, and Polypropylene.
Gas/Steam Motive Jet Pumps
Liquid Motive Jet Pumps
Steam Heating and Mixing Eductors
Principle of Operation for Jet Pumps
While Penberthy jet pumps may differ in appearance,
basic operation is the same. Jet pumps, also known as eductors, operate on
the principles of fluid dynamics. An operating fluid media, which is
referred to as the MOTIVE, place under pressure enters the inlet and is
forced through the nozzle where it is converted into a high-velocity
stream. This high-velocity stream decreases the pressure in the suction
chamber, creating a partial vacuum that draws the suction material into
the chamber where it is entrained by the motive media. Once the SUCTION
stream is drawn in, shear between motive media and the transported
material causes both media to be intermixed and pumped out the DISCHARGE
outlet, dispelled at a pressure greater than the of the SUCTION stream but
lower than that of the MOTIVE. This basic principle of fluid dynamics is
what makes Penberthy jet pumps work. (Jet
This function is the power phase of the pumping operation. At this stage,
the velocity of the motive media increases as it passes through a nozzle.
This phase of the pumping operation takes advantage of the kinetic
properties of the motive media, whether it is liquid, steam or gas.
Because of this, design differences may exist within the motive connection
of the jet pump. For instance, jet pumps with liquid motives use a
converging nozzle, since liquids usually cannot be compressed. On the
other hand, jet pumps with gas or steam motives use converging/diverging
nozzles to achieve trans-sonic flow velocity. The critical flow paths of
all Penberthy jet pumps are smoothly machined with no abrupt turns or
steps in order to produce the most efficient flow during the motive
function. Without this direct flow design and smooth interior surface, the
jet pump would not operate at peak efficiency.
This connection of the jet pump is where the pumping action takes place.
The high velocity stream of the motive causes a drop in pressure in the
suction chamber. This allows pressure in the suction vessel to push a
liquid, steam or gas into the suction chamber of the jet pump. This, in
turn, is entrained by the high-velocity motive stream emerging from the
As the motive flow combines with the suction medium, some kinetic energy
of the MOTIVE is transferred to the SUCTION, mixing and discharging at a
reduced pressure. The amount of pressure that can be recovered depends on
the ratio of the MOTIVE flow to SUCTION flow, plus the amount of SUCTION
pressure built up in the suction vessel. Kinetic energy is converted back
to pressure as the mixed media passes through the diverging taper and is
discharged out the pump.