An artificial-lift pumping system using a surface power source to drive a downhole pump assembly. A beam and crank assembly creates reciprocating motion in a sucker-rod string that connects to the downhole pump assembly. The pump contains a plunger and valve assembly to convert the reciprocating motion to vertical fluid movement.
EXPLANATION OF HOW IT WORKS/ IS USED:
| Figure B: Operational Detail of Sucker Rod Pump Here the plunger is shown at its lowest position. The pitman arm and the crank are in-line. The maximum pumping angle, denoted as theta in the calculations, is shown. L is the stroke length. After one stroke, the plunger moves upward by one stroke length and the walking beam pivots. The crank also rotates counterclockwise. At the end of the upstroke the pitman arm, the crank, and the walking beam are in-line. |
For name and location of parts, see Figure A.
- A motor supplies power to a gear box. A gearbox reduces the angular velocity and increases the torque relative to this input.
- As shown in Figure B, (the crank turns counterclockwise) and lifts the counterweight. Since the crank is connected to the walking beam via the pitman arm, the beam pivots and submerges the plunger. Figure B also shows the horsehead at its lowest position. This marks the end of the down stroke. Note that the crank and the pitman arm are in-line at this position.
- The upstroke raises the horsehead and the plunger, along with the fluid being pumped. The upstroke begins at the point shown in Figure B. At the end of the upstroke, all joints are in-line. This geometric constraint determines the length of the pitman arn.
Hydraulic pump
A hydraulic ram or impulse pump is a device which uses the energy of fallingwater to lift a lesser amount of water to a higher elevation than the source.See Figure 1. There are only two moving parts, thus there is littleto wear out. Hydraulic rams are relatively economical to purchaseand install. One can be built with detailed plans and if properlyinstalled, they will give many trouble-free years of service with no pumpingcosts. For these reasons, the hydraulic ram is an attractive solutionwhere a large gravity flow exists. A ram should be considered whenthere is a source that can provide at least seven times more water thanthe ram is to pump and the water is, or can be made, free of trash andsand. There must be a site for the ram at least 0.5m below the watersource and water must be needed at a level higher than the source
A Jet Pump
A Jet Pump is a type of impeller-diffuser pump that is used to draw water from wells into residences. It can be used for both shallow (25 feet or less) and deep wells (up to about 200 feet.) Shown here is the underwater part of a deep well jet pump. Above the surface is a standard impeller-diffuser type pump. The output of the diffuser is split, and half to three-fourths of the water is sent back down the well through the Pressure Pipe (shown on the right here).
At the end of the pressure pipe the water is accelerated through a cone-shaped nozzle at the end of the pressure pipe, shown here within a red cutaway section. Then the water goes through a Venturi in the Suction Pipe (the pipe on the left).
The venturi has two parts: the Venturi Throat, which is the pinched section of the suction tube; and above that is the venturi itself which is the part where the tube widens and connects to the suction pipe.
The venturi speeds up the water causing a pressure drop which sucks in more water through the intake at the very base of the unit. The water goes up the Suction Pipe and through the impeller -- most of it for another trip around to the venturi.
Advantages
• Increasing the speed before the onset of cavitation, because of the raised internal dynamic pressure
• High power density (with respect to volume) of both the propulsor and the prime mover (because a smaller, higher-speed unit can be used)
• Protection of the rotating element, making operation safer around swimmers and aquatic life
• Improved shallow-water operations, because only the inlet needs to be submerged
• Increased maneuverability, by adding a steerable nozzle to create vectored thrust
Disadvantages
• Can be less efficient than a propeller at low speed
• More expensive
• Higher weight in the boat because of entrained water
• Will not perform well if the boat is heavier than the jet is sized to propel
• Can suffer more easily from cavitation than a conventional propeller
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