The fire water pump, which is the "heart" of hydrant system, sprinkler system and other water extinguishing system. If the fire pump cannot be started in the fire fighting, no fire can be saved. Therefore, the water pump must work continuously during the whole fire fighting to ensure the fire water supply.
Although the function of fire water pump is irreplaceable, it is found that some owners and construction and maintenance managers have not attached great importance to the construction project acceptance and supervision and inspection. The selection and setting of fire water pump are often neglected, resulting in "congenital heart disease" in the water extinguishing system of the building. In view of this, The Croos Pump will talk about the selection and setting of fire pumps.
The selection of water pump
The main consideration of the fire pump is the water flow and the lift of the fire extinguishing system in the fire condition. The fire water pump does not have to consider the change rule of water for the water pump. It is necessary to select the pump of different flow to adjust the water volume to achieve the maximum economic benefit.
When selecting fire pump, the following points should be considered when meeting the flow and lift.
1. We should choose centrifugal pumps as far as possible, as the range of lift and flow is wider for fire water use in general buildings. The centrifugal pump has the widest range, and the variety, series and specifications of the products in the market are the most, so it is easy to select and maintain; At the same time, the centrifugal pump can be used for short time (2 ~ 3 min), and the operation is stable, which has certain significance for maintenance management.
2. The high efficiency water pump should be selected, such as the use of a water pump as far as possible to meet the flow and lift of the whole system.
3. In order to ensure the reliability of fire water supply, a certain number of spare pumps are required. The spare pump should be in the same state as the work pump at any time. And its working ability should not be less than one of the largest fire pump, to ensure that fire water pump can keep the water supply during the fire fighting.
4. When selecting type, we should consider the setting of pump, such as choosing vertical pump to save space.
In addition, to ensure that the fire pump can be started quickly, it should be used from the irrigation water. It is necessary to have reliable and rapid water diversion equipment if the water diversion is difficult.
Setting of the fire pump
The fire pump can only function when the fire extinguishing system protects the building. Normally, the pump is in a state of shutdown, and the normal operation of the fire pump does not affect the normal operation function of the building. In this way, the construction unit often sets the water pump in the position that he believes does not affect the function of the building, the water pump room is set in the room where the position is more partial, the condition is poorer, or share with other room. The scientific and reasonable arrangement of the water pump unit was neglected, which caused great trouble to the maintenance management in the later period, and even caused the pump to not function properly, which eventually led to the spread of fire. Therefore, it is an important condition for the water - extinguishing system to choose the pumping unit and the water pump unit scientifically.
Specifically, the setting of the pump should meet the following conditions:
1. The pump room was the last bastion of fire fighting. Therefore, the fire water pump room is designed to be in an independent building of one or two levels to reduce the fire hazard in the fire, if it is attached to a protective building, a better fire separation is required, if it is attached to a high-rise building, the fire resistance limit shall not be lower than 3h and 2h floor, and it shall be separated from other parts, and a class a fire door shall be used. At the same time, in order to ensure the safety of personnel in and out of fire and fire water pumping stations, fire water pump room should have direct outdoor safety exit.
In addition, keep the light and ventilation as good as possible, and have anti-freeze measures and good drainage facilities.
2. The arrangement of the water pump unit shall be based on the principles of safe operation and convenient management of the pump.
A. The base of the adjacent units should have a certain width of the corridor for the staff to pass through. The motor capacity is not greater than 55 kW and the net distance should be no less than Q8m. But when the motor capacity is less than 20 kW, the aisle width can be reduced appropriately. Of course, it is necessary to ensure that the protruding part of the equipment is not less than 0.7 m between the protruding parts and the wall.
B. For non-horizontal seam pumps, the pump shaft and impeller are usually removed along the axis of the pump during maintenance, therefore, when designing the pump room, we should consider this direction for a certain amount of leeway. The distance of the pump to leave the wall or other units should be greater than the length of the pump shaft and 0.25 m, so as to remove the rotor from the motor, the proper distance should also be set aside.
C. The main aisle width of the pump room should not be less than 1.2 m for safe operation.