Water jet pump (fire service)
The water jet pump of the fire service is a water jet pump , particularly for Lenzen is used. Their main advantage is that they can also pump sandy, muddy and generally dirty liquids. The water jet pump is one of the fittings for water extraction.
It consists of a housing with C pressure inlet, B outlet, bottom sieve, propellant nozzle, collecting nozzle and a suction chamber. The fixed couplings for the inlet and outlet of the pump point in the same direction. In addition, the pump is secured at the inlet for the conveyed water and at the inlet for the motive water with a sieve to protect against major contamination.
In addition to the standardized CB water jet pump, there are also the CA and BA variants with higher delivery rates:
| designation | entrance | output | Delivery rate |
|---|---|---|---|
| Water jet pump CB | C. | B. | 400 l / m |
| Water jet pump CA | C. | A. | 800 l / m |
| Water jet pump BA | B. | A. | 1200 l / m |
A pressurized water supply ("motive water") is required to drive the pump. The mode of operation is based on the injector principle : The pressurized water is directed into the propellant nozzle, whereby it is accelerated. This creates a negative pressure between the propellant nozzle and the catch tube, which sucks in the conveyed water. Motive water and conveyed water mix in the suction chamber and are discharged via the outlet.
If water jet pumps are connected to hydrants, make sure that a non- return valve with a pipe aerator is used. If the water jet pump is withdrawn from a shaft and no check valve is used, the pressure may only be removed when the pump is no longer in the shaft, as otherwise the conveyed water and motive water will drain from the hose lines into the shaft. Alternatively, water jet pumps with a built-in check valve can be used.
Water jet pumps use if you do not re-adding the fuel and feed water a cycle, a lot of water and are increasingly Turbo submersible pumps and especially electric submersible pumps replaced. They were standardized in DIN 14422, which was withdrawn in 2006.
literature
- Diverse: Hamilton - Handbook for the fire brigade . Boorberg Verlag, 21st edition 2012. ISBN 978-3-415-04560-6