What pumps are suitable for pumping high-viscosity fluids?
What type of pump is suitable for transporting high-viscosity fluids? High-viscosity fluids such as honey, jam, resin, glue, lubricating oil, asphalt, pulp, etc., have high requirements on the pump, especially considering factors such as temperature and corrosion. Therefore, we need to be very cautious in the selection of high viscosity pump project. Pumps suitable for pumping high-viscosity fluids include gear pumps, pneumatic diaphragm pumps, screw pumps, industrial hose pumps, and other pumps. The selection of the right pump should be based on the fluid viscosity, flow rate, pump inlet, temperature, the corrosiveness of the conveying medium, pump energy consumption, efficiency, maintenance costs, and other factors.
The most basic form of a gear pump is that two gears of the same size mesh with each other and rotate in a tightly fitted casing. The inside of the casing is similar to an “8” shape, and the two gears are installed inside. body fit tightly. The material from the extruder enters the middle of the two gears at the suction port, and fills the space, moves along the casing with the rotation of the teeth, and finally is discharged when the two teeth mesh. For fluids whose viscosity or density changes during the process, this pump will not be affected too much.
The gear pump has the advantages of simple structure, low cost, pollution resistance, good suction performance under high viscosity, and convenient operation, but the gear pump will generate very high noise. Gear pumps use meshing gears; therefore, abrasive fluids cannot be used in them. And because the size of the gear pump is limited, it cannot be used in large flow occasions.
Air-operated diaphragm pump
The pneumatic diaphragm pump is a type of reciprocating pump, and the diaphragm is the main component. The driver of the pneumatic diaphragm pump uses compressed air to directly drive the diaphragm. Diaphragms and ball seats of different materials can be used in the pump to meet the needs of different working conditions. The common materials of the diaphragm are nitrile rubber, polytetrafluoroethylene, fluoro rubber, neoprene, and so on. Air-operated diaphragm pumps are also non-leakage pumps and explosion-proof products, without any piston parts in the pump. Pneumatic diaphragm pumps can transport all kinds of corrosive liquids, liquids with solids, high viscous liquids, volatile liquids, flammable liquids, and highly toxic liquids, all of which can be exhausted.
The screw pump is an ideal product for conveying high-viscosity materials in industrial pumps. By adjusting the speed of the motor, the screw shaft and rubber can be combined to extrude the medium to the outside. The pump has a wide range of uses, and the stable high-pressure can reach 1.2mpa. The conveyed medium can be extremely high viscosity medium such as toothpaste, glass glue, etc., it can be high temp liquid such as asphalt, coal slurry, tar, etc., it can be food material such as chocolate, jam, starch, etc., and it can also be used as various acid, alkali, salt liquid, and resin delivery pump for pigments, inks, varnishes, glycerin, paraffin. There are many types of screw pumps, which can be selected according to the actual pumped medium and specific working conditions and can be used in high-temp, corrosion, food hygiene, and other scenarios.
Our twin screw pump products have been carefully crafted by R&D personnel. According to the application requirements of petroleum, chemical, paint, oil, medicine, dye, food, and other industries, they have great advantages in conveying high-viscous materials. It can transport media with a maximum viscosity of less than or equal to 5000000mm2/s (such as glass glue transportation in the chemical industry, such fluids are almost immobile), and is widely used in the transportation of media with different properties and viscosities.
Industrial hose pump
The hose is arranged in a U shape in the pump body. When the rotating body drives the extrusion wheel to rotate, the extrusion hose is squeezed by the extrusion wheel and undergoes elastic deformation, and then the suction port forms negative pressure to suck the slurry. Pushed by the squeezing wheel, the slurry is discharged from the outlet, forming a pressure delivery of the slurry.
Industrial hose pumps are mainly used in long-distance transportation, metering pumping, pressure grouting, spraying, etc. of viscous slurry in construction, underground engineering, mining, food, paper, ceramics, and other fields.
The best pump for viscous fluids
The twin screw pump is the best pump for viscous fluids. Since the screw pump performs axial translational movement on the medium, it delivers the medium smoothly without pulsation (especially suitable for asphalt, heavy oil, etc.), and is suitable for transporting liquids that are easy to vaporize, high Viscous media that require self-priming; during the transportation process, the twin-screw pump shows an excellent energy-saving effect. It can be designed as a thermal insulation and sealed cooling system, suitable for medium transportation in high temperatures, corrosion, abrasion, and other occasions. In the structure of the twin-screw pump, a certain gap is maintained between the screw and the screw, and between the screw and the bushing, and there is no direct mechanical wear. Low noise and long life.
The twin-screw pump can completely replace other products, such as replacing the centrifugal pump, sliding vane pump, etc. to pump high viscosity fluid. We know that when the viscosity of a centrifugal pump exceeds 20cSt, the efficiency will drop sharply, while the screw pump can transport even When the liquid reaches 1 million cSt, it still has high efficiency, especially with extremely high volumetric efficiency. Therefore, the higher the viscosity of the conveyed medium, the more consideration should be given to selecting a screw pump to achieve the purpose of saving energy and reducing consumption.
Selection method of high-viscous liquid pump
For pump selection, you should pay attention to the specific viscosity, working temp, medium-specific gravity, medium composition, etc. delivered by the pump. Only by better understanding the conditions of the medium delivered by the pump can you better choose the pump you need.
1. It is necessary to understand the viscosity of the medium conveyed by the pump. Because the viscosity of the medium directly affects the speed of selecting a pump.
2. Understand the nature of the medium conveyed by the high-viscosity fluid pump, such as whether it is corrosive.
3. What is the concentration and specific gravity of the medium conveyed by the pump?
4. The medium conveyed by the pump.
5. Whether the medium conveyed by the high-viscosity material pump crystallizes or solidifies at room temperature.
6. Whether there are suspended substances in the medium conveyed by the high viscosity pump.
7. The medium conveyed by the pump is subject to temp changes.
8. The lubricity, cleanliness, and corrosiveness of the medium conveyed by the pump.
9. Pump inlet pressure, outlet pressure, and installation height.
10. Explosion-proof requirements for high-viscosity liquids pump.
Common faults of the pump to pump high viscosity fluids
1. The oil supply is small.
a. The oil supply volume of the fuel injection pump equipped with a new plunger should be increased by 0.5min/100 times during calibration. If the adjustment is improper: the new plunger will fail faster after working for a period of time.
b. Plunger wears: The phenomenon of serious wear of the plunger is that there is no idle speed, high speed does not drop, and the stop handle needs to be pulled to slow down, commonly known as fake speeding.
2. No outlet pressure or lack of pressure
Analysis of the cause of the failure: The pump does not generate pressure, it only outputs flow. Low or no pressure, indicating that the pump has not sucked liquid or has serious leakage.
Counter measurement: The output power of the motor is too small, and when the displacement of the viscosity pump is selected too large or the pressure is adjusted too high, it will also cause insufficient pressure. Of course, no pressure can be displayed when the pressure gauge is damaged or the pressure gauge orifice is blocked. At this time, a new pressure gauge can be replaced for inspection.
3. There is air in the pump.
a. The transmission shaft oil seal fails.
b. There is air in the low-pressure oil circuit.
4. No flow or lack of liquid output
Cause and solutions: If it is confirmed that the pump has no flow output, it may be because the pump is installed incorrectly, the steering of the pump is wrong, or the suction side (inlet and suction pipe) is blocked, the outlet check valve is reversed or stuck, or it may be the driver The shaft is broken. The high-viscous fluid pump will cause insufficient liquid output when the speed is too low. This phenomenon is often caused by slippage of the pump drive or insufficient power. At this time, the actual speed of the pump, the connection between the pump and the motor, and the power matching status should be checked.
5. The speed is unstable and the diesel engine shakes.
a. When an abnormal phenomenon occurs, check whether the fuel injector is invalid, and then check whether the oil outlet valve seat of a certain cylinder is loose.
b. There is air in the diesel or the oil outlet valve that fails, and the idle speed is too low, which may cause the diesel engine to vibrate or cause the speed to be unstable.
6. Abnormal vibration and noise
Because the viscosity of the working medium of the high viscosity pump is relatively high, it is easy to cause a hollow phenomenon and cause a large noise.
7. No oil supply, no oil from the injector.
a. The oil supply pressure is too low: the high-pressure oil pipe is over-tightened, and a torque is stored. When the diesel engine is working, the temperature rises or the vibration causes the torque to rebound, and the oil outlet valve becomes loose, which can also cause the oil pressure to drop. In most cases, it is caused by severe wear of the plunger or failure of the oil delivery pump, wall plug of the low-pressure oil circuit, and lack of oil in the fuel tank.
b. Fuel injection pressure is too low: Generally, it is due to incorrect adjustment or clogged injection holes.
Additional maintenance work:
For daily maintenance, whenever the viscosity material pump is shut down and does not work, the corresponding cleaning agent will be selected according to the nature of the conveyed material to effectively clean the pump, and finally, it must be washed with clean water to ensure that the pump is clean and hygienic.
FAQ about high-viscosity pumps
Q1. What kind of pump should be used for pumping the slurry, paste, and viscous liquid?
A: Generally speaking, the effect of a screw or gear pump is better.
Q2. Which pump types are better for pumping viscous chemical raw materials?
A: A gear pump can be used. If the viscosity is greater than 100,000, we can give priority to our twin-screw pump. The viscosity of its conveying medium can reach 5 million mm2/s
Q3. What kind of pump is better for conveying viscous chemical raw materials? Centrifugal pumps seem to be incapable
A: Generally, displacement pumps are used to transport viscous media, including screws, gear, rotor, diaphragm, reciprocating, progressive cavity pump, etc.
Q4. What kind of pump should be used for conveying high-viscosity materials?
A: The screw pump is the first choice, followed by the outer circulation rotor, gear pump and so on. If the medium contains large particles, a hose pump can be used.