Submersible pump
As a submersible pump , Süffelpumpe or Söffelpumpe refers to a portable or stationary built-in ( centrifugal -) pump which is immersed in the liquid to be conveyed. It is mostly powered by electricity, all live parts are isolated from the environment. However, there are also versions that work with hydraulics, since the pump unit is then lighter because the motor is omitted, but a corresponding hydraulic pump is required here. The liter output ranges from around 100 l / min to 2,200 l / min. Submersible pumps can be equipped with a float switch. This is used to protect against dry running or to regulate the level.
Submersible pumps in disaster control
The tasks of disaster control , in particular of the technical relief organization , require submersible pumps with high flow and suction capacity in the elimination of damage situations with water involvement in small and medium-sized operations. According to STAN, the emergency services are to be equipped with submersible pumps with performance parameters of 400 l / min and 800 l / min. These are assigned to each rescue group according to STAN and stowed in the vehicles. In addition, the technical group water damage / pumps of the THW is equipped with further submersible pumps with performance parameters of up to 2,200 l / min. The requirements of the THW relate to a high throughput as well as the possibility of dry suction, continuous operation and the lowest possible residual water level (flat suction).
Disaster control uses the comparatively small submersible pumps (see HCP Modules ) to process operations in residential and commercial facilities, in particular for pumping out flooded basements, sewage treatment plants and wastewater with a high solid content. The portable submersible pumps from the Water Damage / Pumps department can process solids up to 80 mm in size without damaging the pump's mechanics.
Submersible pumps at fire departments
The fire brigades use submersible pumps for technical assistance . In the flood relief are generally used submersible pumps and turbine submersible pumps. They have largely replaced the classic water jet pump.
Submersible motor pumps (also known as submersible pumps for short) (TP) are operated electrically. Depending on the delivery rate, a distinction is made between types TP 4/1, TP 8/1 or TP 15/1 with a flow rate of 400, 800 or 1500 liters of water per minute at 1 bar pressure. Depending on the size and delivery rate of the pump, C, B or A Storz couplings are used as outlets . Turbine submersible pumps (TTP) are, however, driven by the motive water, with the pressure of a fire pump is pumped into the turbine submersible pump and drives the turbine wheel. Since, in contrast to a water jet pump, it has separate outlets for motive and dirty water, it can be operated in the circuit fire pump - submersible turbine pump - fire pump. The dirty water is discharged through another outlet.
A special application for submersible pumps is the use in extinguishing water wells when the water level is so low that the geodetic suction height would be exceeded and extraction with a centrifugal fire pump would not be possible.
As a rule, submersible pumps are not used for pumping extinguishing water, as the extinguishing water flow rate might not be sufficient. In special but rare cases, for example if the geodetic suction height for normal fire-fighting centrifugal pumps is too high or the suction line is too short, these are still used. A few fire brigades generally use submersible pumps to extract extinguishing water from open waters, but this is more the exception than the rule. For extracting large flows of extinguishing water, e.g. B. in industrial fires, fire pumps and swimming pump systems such as the "Hytrans Fire System" (HFS) are used.
Dirty water pumps represent another area for submersible pumps .
Submersible pumps in the water supply
Submersible pumps are used in smaller wells and cisterns for the water supply . A special submersible pump is the submersible motor pump handle that in the multi-stage design, larger amounts of water and heads and even narrow by design, well pipes can be installed.
Submersible pumps in sewage disposal
In the field of sewage disposal, submersible pumps are used in pumping stations. Reliability is particularly important here. The coarser the admixtures, the greater the free passage of the pumps must be in order to be able to rule out clogging as far as possible.
Since pumps with large free passages (in the sewage area, 80 mm ball passage and more) always require a corresponding pressure pipe, there is the possibility of working with cutting wheel pumps for the disposal of sewage from residential buildings or other individual objects , which crush the sewage and transfer it accordingly Convey tightly dimensioned pressure lines (from DN 32 in pressure drainage ).
Flat vacuum cups
Flat suction cups are also submersible pumps. With their flat strainer, they have the advantage of being able to suck in water that is very low. Flat vacuum cups can be used from a water level of one millimeter.
Submersible pumps in the aquarium hobby
Various types of filters in aquaristics use submersible pumps to pump the aquarium water through the filter substrate or back into the aquarium . This applies to most internal filters . Industrially manufactured internal filters often have an integrated centrifugal pump. The Hamburg mat filter , which is usually made in-house, is often operated with appropriately dimensioned submersible pumps that have to be purchased separately and which can be very small in terms of their external dimensions. The model in the illustration measures around 4 cm × 4 cm × 3 cm and can deliver up to 240 l / h. In such pumps, the rotor sits on a magnetic axis and rotates, virtually floating in the water, with very little friction and quietly.
Performance of submersible pumps
The power of a submersible pump or the power requirement (as electrical power to drive the motor of the pump) is calculated using the following formula:
with Q: delivery rate, p: delivery pressure and : overall efficiency of the submersible pump.
The unit for power is W (watt).
The delivery rate Q indicates the volume of the medium to be delivered that can be pumped per unit of time. The delivery pressure p is the pressure that a submersible pump can generate. The delivery pressure is often given as the delivery head. Both parameters, delivery rate and delivery head, are interdependent. The same always applies here: The delivery rate decreases with increasing delivery pressure or vice versa: the lower the delivery pressure, the greater the delivery rate. This relationship is shown in characteristic curves. The overall efficiency is determined by the ratio between the power that can be called up on the drive shaft (the actual pump power) and the electrical power used to operate the motor. The overall efficiency of a submersible pump can also be taken from a characteristic curve. Each submersible pump has its own characteristic curves that only apply to it. These can be found in the relevant technical documentation for the pump.
Web links
- Federal Office for Civil Protection and Disaster Relief - Downloads - Fire Service Regulations (FwDV) 1 (PDF, 10 MB, as of 09/2006 with editorial additions up to 03/2007), Section 11, pages 68–69
Individual evidence
- ↑ HECTAS Facility Services: When there's a fire at Volkswagen ...
- ↑ See THW-Helfervereinigung Bad Oldesloe - CHIEMSEE pump ( Memento from February 21, 2011 in the Internet Archive )
- ↑ a b Training of volunteer fire brigades, basic training - training service in the fire brigade; Neckar-Verlag, 7th edition 2005, page 151f