Jet Pump (Wells)
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.
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 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
Lift Disk Pump
This type of pump uses flat disks attached to a chain or rope. The disks draw water up a tube.
This type of pump is probably thousands of years old. It is similar to a Rag Pump or Bucket Pump.
This pump can still be found on farms everywhere. The maximum suction to the lower valve (called the FOOT VALVE) is about 30 feet.
Water enters the lower chamber when the movable sealed plate is raised. The red valve is open and the green valve on the plate is closed.
When the plate is pushed back down, the red valve closes, and the liquid in the lower chamber is forced through the green valve, which opens.
On the next upstroke of the plate, the liquid which passed through the green valve on the previous downstroke is raised and spills out the spout.
Magnetic Flux Pump
Magnetic Flux Pumps (also known as Electromagnetic Pumps) have no moving parts. These pumps have very limited uses since very few liquids which people normally pump are good conductors of electricity, a requirement for this pump to work.
There are a wide range of capacities and models, using different principles of electromagnetism. When they can be used, Magnetic Flux Pumps offer several advantages:
First, there are no seals. This reduces the chance of spills because seals can be a major source of leaks. It also reduces maintenance, increases reliability, and makes it easier to move high-temperature liquid metals.
Second, because there are no moving parts (no journals, no bearings, no vanes, etc.), vibration- and friction-induced wear is reduced, downtime is reduced, and reliability is increased.
The pump shown below works like a liquid electric motor. The liquid between the copper conductor bars acts as a conductor.
Quoting Nuclear Reactor Engineering (by Glasstone and Sesonske; see bibliography for full reference):
“If a conductor in a magnetic field carries a current flowing at right angles to the direction of the field, a force is exerted on the conductor in a direction perpendicular to both the field and the current.” (Page 406.)
Immediately upon entering service in a nuclear reactor, these pumps start to become radioactively contaminated (for example, with Sodium-24), thus becoming at the same time, both extremely dangerous, and yet impossible to discard safely after use.