Q. Select one type of fire pump, and explain how the fire pump operates. Details in the essay shall include the water supply, operation, pump driver, controller, components, and discharge.
The most common fire pump used in the fire service is the centrifugal pump. This pump uses centrifugal force to generate pressure to move water.
The components of centrifugal fire pump include: The pump housing which includes all the moving parts. The impeller has curved vanes to help build water pressure. And the volute of a centrifugal pump is the casing that receives the water being pumped by the impeller, slowing down the fluids rate which increases the pressure. A volute has a curved funnel that increases in size as it approaches the discharge port. The fire pump works by drawing water from an external source. The water enters through the eye of the rotating impeller which creates a centrifugal force that sends high pressure water around the volute then exits the through the discharge. The stripping edge and centrifugal force inside the volute prevents water from being recirculated back into the impeller. (Sturzenbecker, 2012) The higher the water pressure entering the pump, the higher the pressure will be through the impeller and discharge. The benefits of having higher water pressure entering the fire pump is the impeller needs to spin at a reduced rate to achieve the desired PSI. On a fire truck water will flow freely flow through the fire pump and out the discharge. If the fire pump fails water will continue through the pump and out the discharge. (Sturzenbecker, 2012)
In order to drive the fire pumps drivers are used to turn the fire pumps. The three drivers used are: Electric motors, diesel engines, and steam turbines. Each of the drivers must have enough power to turn the pumps at a rated speed under all load conditions. (Sturzenbecker, 2012) Each of these drivers have there advantages and disadvantages. The electric motor is dependable and requires very little maintenance. The down side to electric motors it is dependent on an external electric source. If electricity is interrupted the pumps stop working. The steam turbine is the least common of the drive motors. This application can be found in older buildings with an uninterrupted supply of steam in sufficient quantities. (Sturzenbecker, 2012) The best choice
For pump drivers would be the diesel engine. The diesel engine has its own external power supply. The diesel engine is the only internal combustion engine suitable for fire protection applications. (Sturzenbecker, 2012) These engines need to be fitted with a variety of gauges and shut down devices to ensure its proper operation.
To control the operation of the fire pump a pump controller must be used. These devices govern the operation of the pumps. These devices can be designed to operate the pump automatically by using electronic circuits or manual operation. (Sturzenbecker, 2012)
Knowing how all of these different types of pumps operate is vital for safety of firefighters and public. Making sure that one knows how the equipment works to prevent malfunction due to misuse when it is needed most. Proper use will ensure efficiency at the fire scene and therefore decease property damage and potentially saves lives or civilians and firefighters alike.