Helico-centrifugal pump

Brand Yongsheng

The hellico-centrifugal pump was developed by a Peruvian research institute in 1960s, it was used to transport fish at that time, later, it was started to be used for conveying solid-liquid binary fluids, it can also be used for drainage and conveying liquids with high viscosity. To prevent clogging by solid matters and ensure their smooth outflow, the open (closed) type impeller has a twisted helical blade, it is on the conical hub body and extends out from the suction inlet along the axial direction, the radius of the blade is gradually increasing to form a helical propulsion effect, the impeller of the scroll portion generates a centrifugal effect as that of a general centrifugal pump. The acute angle part of the impeller pushes the debris to the pace near the axes, and then the debris are pushed further forward by spiral effect. This pump is like a combination of a positive displacement pump and a centrifugal pump, so it is called helicon-centrifugal pump. As this pump has the functions of a displacement pump and a centrifugal pump, so it has the following features compared with general centrifugal pumps:

Helico-centrifugal pup
Ordinary impurity pump
Vortex pump
Fig.3. Performance curve diagram
IV. Installation and operation methods, operation precautions and maintenance of the pump
1. Pump installation and operation methods
1. Before installation the use, the user should carefully check whether the appearance of the electric pump is in good condition, check each connection to see whether there is any loose or leakage, and whether the electric cable is damaged or cracked. And carefully check flow rate, head, power etc on the nameplate, in order to ensure correct use.
2. Use a megameter to measure the electric pump’s cold insulation resistance, which should be greater than 50 megohms, if it is lower than this value, the excessive moisture should be removed before it is used again;
3. The pump should have a separate power switch, and should be reliably grounded, ;
4. If the cable of the electric pump is not long enough, the extended cable must have a larger diameter which should be two times of that of the original cable, and the extended cable should be firmly connected and the number of connectors should be minimized and cable connector, and no connector should be submerged in water;
5. Check whether the pump can normally start and run (empty running should not exceed two seconds), whether the rotating direction is correct (the running direction is indicated on the pump cover), if the rotating direction of the three-phase electric pump is incorrect, you can correct it by changing any two main lines;
6. Tie a rope on the handle or hoist ring of the pump in order to place it, it is strictly prohibited to use electric cable of the pump to hang, place, lift or pull the pump.
2. Precautions in use of the pump
1. When the pump works, pay close attention to the water level, never allow the pump be above water surface or run without water;
2. When the pump works, do not touch and move it to prevent accidents;
3. Whenever the electric pump is used, an over current protection switch should be installed to protect the electric pump and cut off the power if there is any exceptional circumstance, so as to ensure that motor windings will not burn out;
4. All kinds of electric pumps should be well grounded whenever they are used, the yellow-green colored wire should be sued as ground wire and ground symbol should be used according to the requirements of the new standard; if necessary, use a multimeter to measure the ground wire in order to prevent wrong wiring which may cause accidents, if the pump can not be grounded, a leakage protector should be used;
5.Do not use the pump if the three-phase voltage is not stable or if there is an open phase, so as not to burn the windings;
6. In case of electric pump failure, no one, except professional repairers, is allowed to disassemble the pump, after disassembly, the electric pump must be check for air tightness, it can be used again only after the test result shows that it conforms to the requirements.
7. The electric pump is strictly prohibited to run without water
8. The cable connector should not be emerged in water, if the cable ruptures or scratched, it should not be used so as to prevent water from infiltrate into the cavity of the electric pump.
Note: The used head shall not be less than 0.7 time of the rated head.
3 Care and Maintenance
1. Regularly check the cold insulation resistance between winding and cabinet of the electric pump, which should not be less than 50 megohms, if it is lower than this value, it should be solved, or disassemble the electric pump to dry the stator, the pump can be used again only after the insulation resistance becomes normal;
2. After each use (especially after pumping viscous slurry), the pump should be placed in running water for a few minutes to clear off the dirt inside and outside of the pump, and wipe off the moisture, then store the pump in a dry and well-ventilated place, the pump should be emerged in water it is no used for a long time, when the temperature is too low, take the pump out from water in order to prevent electric pump casing from frost cracking;
3. Check the cable, carefully examine the cable surface to see whether it is scratched or broken, or has any small holes and other defects, otherwise, the cable should be replaced immediately;
4. After the electric pump is disassembled and repaired, its sealing performance must reach 0.2Mpa, there should be no leakage during the pressure test lasting for 3min;
5. After the electric pump works for 1000 successive or accumulated hours, check the fasteners and sealing parts, if there is any oil leakage, timely replace the related parts, No. 10 machine oil should be used in oil chamber;
6. The machine oil of the electric pump should be replace once every 1500 accumulated working hours (the oil chamber is in the water inlet joint), unscrew the oil plug screw, add 10 # methane oil up to 80% of the capacity of the oil chamber;
7. The wearing parts (such as rolling bearings, overall oil seals) of the electric pump should be replaced once every 3000 accumulated working hours, in order to prevent greater losses caused by seal damage;
8. If the pump is not used for a long time, it should be washed clean, if the surface coating falls off, it should be painted again, after repainting, store it a cool, dry and well ventilated place for safekeeping.
Note: To prevent electric shock, make sure to cut off the power before repairing or cleaning the electric pump.

Motor model

Yz280A-4/90kw

Date

2011-3-28

Motor model

R1 Ω

R2 Ω

R3 Ω

Insulation resistance mΩ

Inter-turn status

Withstand voltage 1.76kv

Locked-rotor voltage V

Ikx A

Locked-rotor power W

Open-circuit voltage　V

Iox A

No-load power　W

Test result

0.039

0.039

0.038

500

Qualified

Qualified

100

200

12500

380

43.2

16003

Qualified

Rules of submersible motor control cable wiring colors:
Red ------ lower float ball
Black------ upper float ball
White ------bearing temperature measurement
Blue ------ stator temperature measurement
Yellow ------ oil and water control head
Yellow ------ ground wire (ground yellow wire with a knot)

Control cable color	Two blue wires	Two black wires	Two red wires	One yellow wire	Two white wires	One yellow wire
Sensor name	Winding temperature measurement element	Leakage float switch inside the wiring box	Leakage float switch inside the motor	Leakage electrode inside the oil chamber	Bearing temperature measurement element	Ground
Normal state resistance value	0	Disconnect	Disconnect	≥33k％Ω	0
Function	≥4kΩAfter the stator coil over-temperature protection device actuates when the temperature exceeds 135℃	When junction box electric leakage occurs, the float switch state transition resistance R≈0	When motor cavity electric leakage occurs, the float switch state transition resistance R≈0	When water content of the oil reaches 10%, the electric resistance of the oil and water mixture <33kΩ	When bearing temperature exceeds 95℃, R≈∞