WATER TREATMENT PLANT EQUIPMENT
There are a number types, sizes and uses of pumps in water treatment. This unit of instruction introduces the most commonly uses type of water system pump such as submersible pump and horizontal pump. This part describes various types of pumps, the basics concepts behind their operation. The lesson concludes with a brief commentary on pump operation and the other available pumps. The purposes of pump are used to convey liquids from the point to the next. There are some types of pumps used in GSL Water to transfer water to certain place. The pumps are:
A) LLP (low lift pump)-submersible pumps
B) HLP (high lift pump)- horizontal pumps
Term and definitions
Vacuum ; normally defined as a pressure below atmospheric pressure hence , flow is created from a high – pressure area to a low – pressure area.
Amperage; the strength of an electrical current in amperes. The amount of electric current flow, similar to the flow of flow of waters in litres /minute, m³/hr or l/s, etc.
Ampere; the unit used to measure current strength.
Back pressure; a pressure that can cause water to back flow into the water supply. The down stream water pressure is greater that upstream pressure in the system.
Back-flow; Reverse flow condition caused by a difference in water pressure.
Cavitations; the formation and collapse of a gas pocket or bubble on the blade of an impeller surface. Normally associated with rumbling noise from the pump.
NPSH ; Net Positive suction head (NPSH) is a measure of amount of suction head present to prevent vaporization at the lowest pressure point to pump.
Current ; the movement or flow electricity measured in amperes.
Static head ; vertical distance (in meters) equal to the pressure point in the pump.
Friction head ; the loss of energy lost by friction losses in pipes, fittings, etc. measured in meters.
Total head ; the total resistance to be overcome when pumping. it is the summation o static head plus friction head.
Impeller; a rotating set of vanes in a pump designed to pump or lift water.
Multi-stage ; a pump that has more than one impeller.
Voltage ; the electrical pressure available to create the flow of current when the circuit is closed , measure in volts.
(Term and definitions take from operator certification programme, grade 2)
- LLP (low lift pump),
LLP (Low lift pumps) is a submersible pumps that has been used in low lift pump house. This normally involve the pumping of raw , untreated water from the source to the treatment plant. This pump used in Selingsing canal to take the raw water and then transfer the raw water to the treatment plant for the next process.
Advantages and disadvantages of submersible pumps.
Low levels of noise and vibration
Ease of mounting
Stability and uniformity of discharge
Versatility of mounting position.
Leaking in the head of pumps will broke the electric component
Always change the oil in the pumps.
Picture: Submersible pump
- HLP (high lift pump),
HLP (high lift pump) is a horizontal pump. It located in high lift pump house in the treatment plant. This is normally the pumping of treated water to the distribution system under pressure. Normally associated with flows at high where the treated water must been transfer to the reservoir.
This pump move water by the force created by the impeller rotating within the casing. They have a rotating pump casing. Water enters at the centre of the impeller. When the impeller turns around (rotates), water is forced out of the pump radially due to forces. The result is a vacuum at the centre or the eyes and this gives the needed condition to move the treated water.
Continuously water is being drawn toward the vacuum (eye) due to the low pressure created and at the same time it is being discharged by the force of the impeller to the discharge point this gives a continuous and smooth flow of water.
Picture: HLP(high lift pump) in pump house 3
Cross sectional view
(picture taken form Grunfos Hs)
VIBRATION OF PUMPS
Using the SKF vibration pen can give the vibration level of pump. This is important thing where we can detect the status of pumps. So from that, we can know what the specific problem that happen in the pump. The common problem can be detect by the vibration SKF pen are:
heat of pumps
grease level in the both side of casing (inboard and outboard pump)
Picture: Vibration can be check by using the SKF vibration pen
(picture taken from GSL Water Sdn. Bhd)