Centrifugal Slurry Pump is a kind of general mechanical equipment, which is widely used in petroleum, chemical industry, electric power metallurgy, mining, ship selection, light industry, agriculture, civil and national defense departments, and plays an important role in the national economy. According to the statistics of 79 years, the output of pumps in China has reached 1.256 million. The electric energy consumption of the pump accounts for more than 21% of the national electric energy consumption. Therefore, it is of great significance to reduce the energy consumption of pumps.
In recent years, our pump industry has designed and developed many efficient and energy-saving products, which has played a positive role in reducing the energy consumption of pumps. But at present, in all fields of national economy, because of the unreasonable selection, many pumps are in the unreasonable operation status, low operation efficiency, and waste a lot of energy. Because of the unreasonable type selection, other pumps can not be used at all, or the use and maintenance costs increase, and the economic benefits are low. It can be seen that reasonable pump selection is also of great significance for energy conservation.
The so-called rational pump selection is to comprehensively consider the investment and operation cost of pump unit and pump station and other comprehensive technical and economic indicators, so as to make them conform to the principles of economy, safety and applicability. Specifically, there are the following aspects:
When choosing the slurry pump, we need to know where the slurry pump is used and the name of the medium, such as coal mine, mine, tailings, metallurgy, steel, sewage treatment, etc. Secondly, we need to know the flow, lift, diameter, specific gravity, particle content, viscosity, corrosiveness, pH value and temperature of the slurry pump.
There are many types of centrifugal slurry pumps. Different types of pumps should be selected according to the properties of the slurry. For example, GL type pumps can be selected for low abrasion slurry with a weight concentration of less than 30%; GAH type wear-resistant alloy metal pumps can be selected for high concentration strong abrasion slurry pumps; Gahr type rubber slurry pumps can be selected for high concentration non angular slurry pumps. When the height of the liquid level changes greatly and it is necessary to work under the liquid, it should GSP (GSPR) pump is selected. When high lift transmission is needed, ZGB pump, kzj pump and GHH pump are selected. When the particle diameter is large, GG type sand pump can be selected.
After the pump type is determined, the head and flow are the basis for selecting the pump size and whether it is connected in series. For the transportation of high concentration and strong abrasive slag slurry, the highest revolution of the pump (the highest revolution of multiple revolutions in the performance curve) is generally not selected, and it is appropriate to select the revolution of about 3 / 4 nmax. When the selected pump is at 3 / 4 nmax, the flow rate is suitable but the head is not reached, so multiple pumps can be used in series. For slurry pump, the flow range should be limited for different slurry; for slurry with high concentration and strong abrasion, the flow should be within 40-80% of the flow corresponding to the highest efficiency of the pump; for slurry with low concentration and abrasion, the flow should be within 40% – 100% of the flow corresponding to the highest efficiency of the pump. Generally, it is not selected in the range of 100% – 120% of the flow corresponding to the highest efficiency.
During the operation of slurry pump, the performance of the pump is declining because of the wear of the flow passage parts, until it can not meet the working condition requirements. In order to make the pump run near the rated working condition for a long time, a head margin is usually added during pump selection. The general margin is 10% of the rated lift.
There are many materials available for the overflow parts of the slurry pump, which shall be determined according to the characteristics of the room (particle composition, particle size, shape, hardness, concentration) and Chemistry (acid, alkali, oil) in which the slurry is delivered.
Slurry pump mainly has packing seal, expeller seal and mechanical seal. The expeller seal is generally used under the backflow operation, and the pressure of the upper management should be less than 10% of the pump outlet pressure. This type of shaft seal does not add the shaft seal water, but the use of the expeller seal increases the power consumption, generally about 5% of the rated power. The gland seal water shall be added to the packing seal to ensure enough water. The water pressure of the gland seal is equal to the pump outlet pressure plus 35kpa. The mechanical seal shall be added with the gland seal water with good sealing performance and no leakage.
The drive mode of slurry pump includes V-belt drive, elastic coupling drive, gear reducer drive, hydraulic coupling drive, frequency conversion drive device and silicon controlled speed regulation. Among them, elastic coupling and V-shaped triangle belt are cheap and easy to assemble and disassemble, which should be preferred. But the V-belt will increase the power consumption by 5%.
There are many installation types of slurry pump. CV drive, DCZ drive, CRZ drive and ZVZ drive.
When the pump shaft power is calculated, considering the factors such as pump start and flow fluctuation, the standard motor should be selected with a certain power margin coefficient. Generally, 1.1-1.2 is adopted for the rich system, small value is adopted for the high power, and large value is adopted for the low power.
Our company has been specializing in the production of slurry pumps for 20 years in China, and has been one of the largest manufacturers of slurry pumps in China. With rich experience, there are more than ten professional slurry pump engineers, who can choose a variety of slurry pumps for customers to meet their different needs. If you don’t know how to choose an efficient and energy-saving slurry pump suitable for your working condition, please feel free to contact us-Gempump China.