The sand transfer pump rated torque is an important indicator that determines its dynamic performance. Many professional customers have communicated with OCEAN PUMP engineers about this parameter, because the sand transfer pump torque will directly affect the sand pumping capacity, and overload capacity under extreme working conditions. Reasonably designed torque can ensure the stable operation and long service life of the sand transfer pump unit under harsh working conditions. OCEAN PUMP has been engaged in the R&D and manufacturing of sand transfer pumps for more than 20 years, and has accumulated a lot of industry experience. So what is the effect of torque on the sand pump system? This article explains the calculation and model selection methods of the sand transfer pump rated torque and supporting engine torque from a professional perspective, for reference and exchanges by peers and customers.
1. The sand transfer pump and supporting power torque significance.
Torque is a special moment that causes an object to rotate. Engine torque refers to the torque output from the crankshaft of the power plant. When the power is fixed, it is inversely proportional to the speed of the power equipment. The faster the speed, the smaller the torque, and vice versa, it reflects the load capacity of the power equipment within a certain range.
Torque (also called torsional moment) is a special moment in physics. It is the product of strength and force arm. The international unit is Nm. You can also see the torque units of kg·m and lb-ft. Because G = mg, when g = 9.8, the gravity of 1kg is 9.8N, so 1kg·m = 9.8N·m, and lb-ft is a unit of torque for 1 inch, 1lb = 45536kg; 1ft = 0.3048m, 1lb-ft = 0.113826kg·m. In people’s daily expression, torque is usually called torsion. To give a popular example, for example, when the human body is in motion, the power is like the body durability, the speed is the movement frequency, and the torque is the body explosive force. People use a shovel to dig sand, the shovel is the torque, the digging frequency is the speed, and the human stamina is the power. With a certain physical strength (power), use a large shovel (high torque) for digging, the frequency must be low (low speed), and the frequency of a small shovel (low torque) must be high (high speed). The final decision on how much sand you can dig depends on your physical strength (power).
In the sand pumping construction process, under the condition of fixed supporting power, large particle sand pumps and marine sand pumps are low-speed sand suction pumps, so the torque is greater; while small sand pumps and submersible sand pumps belong to High-speed sand transfer pumps, so the torque is smaller. But no matter what kind of sand suction pump, the sand pump with larger torque, the use effect is definitely better.
2. Sand transfer pump supporting power torque calculation formula.
The torque calculation formula for the sand dredging pump supporting power is: T=9550*P/N.
T is the torque, 9550 is the conduction coefficient, P is the rated power of the power equipment, and N is the rated speed of the power equipment. The formula can show that torque and power are proportional to each other and inversely proportional to speed. Take the Weichai 6170ZC600-4 marine diesel engine as an example. The power equipment of the sand transfer pump has a rated power of 450kw and a speed of 1500rpm. T=9550*450/1500=2865N*m.
The same calculation formula is applied to calculate the motor torque. Taking the YX3-90S-6 motor as an example, the rated power of the sand transfer pump supporting power equipment is 0.75kw, the rated speed is 910rpm, and the formula T=9550*0.75/910=7.87N*m. The motor under the same power has a high speed and a small torque. Take the YX3-801-2 motor as an example. The rated power of the equipment is also 0.75kw, but the rated speed is 2840rpm, T=9550*0.75/2840=2.52N* m. Also 0.75kw, the torque at 910rpm is much greater than at 2840rpm.
3. What’s the application of torque for sand transfer pump?
a. Torque application in the sand transfer pump
The torque of the sand transfer pump will directly affect the maximum sand pumping capacity and the overload capacity under extreme conditions. Reasonably designed torque can ensure the stable operation and long service life of the sand suction pump unit under harsh working conditions. When designing sand pump equipment, engineers will consider the actual utility of torque in operation, and thus design a high-torque sand pump machine. According to the different working conditions requirements, the design engineer of the sand pumping machine will first increase the outer diameter and width of the impeller to reduce the speed under the condition of the same flow and head. This will not only increase the torque, but also reduce the flow components wear resistance. Under the condition of low speed and high torque, it can achieve continuous and efficient sand pumping for a long time. At the same time, in order to match the high-torque impeller, the sand transfer pump shaft and bearing design also correspondingly increase the strength to ensure stable operation under high-torque conditions.
b. Application of torque in sand transfer pump and supporting equipment.
Diesel engines have large torque, strong explosive power, and are much more powerful under extreme conditions. They are generally low-speed machines. Diesel engines are also less worn and have a long life. Commonly used diesel engines such as Weichai, Zichai, and Yuchai are low-to-medium speed engines. Matching the gearbox is equivalent to reducing the output speed of the diesel engine, which can increase the output torque of the engine. The gear power loss is extremely small and can be ignored. The role of torque in the motor is the same as that of the diesel engine. If the belt pulley needs to be matched, it is recommended to use a low-speed machine, that is, 10 poles> 8 poles> 6 poles> 4 poles> 2 poles. The greater the torque in the sand pump, the more powerful it is, the better the power will be, and it can be opened instantly when encountering large particles or high-concentration working conditions. The greater the supporting power torque at the same power, the better.
c. In addition, there will be torque requirements in the assembly of the sand transfer pump.
Generally speaking, there are certain requirements for screws on mechanical parts, such as tightening torque and loosening torque. The torque used to tighten the teeth is called the breaking torque, so the size of the tightening torque cannot exceed the breaking torque. Generally speaking, the tightening torque is 70%-80% of the loose torque, which ensures the screw tightening strength and does not make the screw slip. The loose torque is the key to ensure the screw life after tightening. According to the screw material, the screw size is different, generally less than the tightening torque. In the assembly of sand pumps, diesel engines or ships, screws and other devices also have rated torque requirements. During the assembly, the bolts are installed strictly according to the fixed torque to ensure that the force is even, and the assembly is firm and does not slip off during continuous work.
4. How to match the diesel engine and gear box to ensure the maximum torque of the sand pump unit?
a. First, get the sand transfer pump shaft power through calculation, and determine the coefficient according to the medium specific gravity and the applicable working conditions. Past experience is that the shaft power is multiplied by a factor of 1.2-1.3, and the diesel engine is multiplied by a factor of 1.2-1.3.
b. Secondly, match the diesel engine according to the sand transfer pump The domestic brand takes 80% of the economic speed, and the imported model takes the rated speed, if it does not match the matching gear box or pulley.
c. After determining power and speed, Basically, the rated torque of the diesel engine or motor is greater than that of the sand pump. If the belt pulley is selected, the torque loss is large, and the horsepower needs to be increased.
d. It is also necessary to pay attention to the sand transfer pump steering and the diesel engine. Generally, the gearbox is hydraulically controlled forward and backward, so the forward and reverse gear has no loss on the diesel engine power and has no effect on the gearbox life.
OCEAN PUMP pays attention to the entire sand transfer pump production process. When the impeller and bearing are matched, high-torque products under different working conditions are designed to realize the continuous and stable sand mud transportation under high-concentration, large-flow and long-distance conditions. In the process of supporting power, select international and domestic high-cost power equipment to ensure that the diesel engine or motor torque can be better used; in-depth cooperation with auxiliary equipment manufacturers such as gearbox factories to design low-speed ratio gearboxes suitable for the sand transfer pump working, to ensure that the diesel engine is matched with the sand pump power and torque curves.
5. Torque design use case of sand transfer pump.
A customer from Jiangxi chose the 450GN-40 marine sand transfer pump produced by OCEAN PUMP. Considering that the local sand was relatively loose and the sand pumping concentration was high, after field surveys, OCEAN PUMP engineers selected high-torque diesel engine to match the gearbox. 450GN-40 marine sand transfer pump has a flow rate of 3100m³/h, a head of 40m, and a speed of 550rpm. The shaft power can be calculated to be 441.6kw. And through calculation, the rated torque T=9550*441.6/550=7667.8N*m, OCEAN PUMP engineers selected Jichai 12V190 type 1200 hp/1350rpm diesel engine, and Hangzhou Fada 1260 type 2:1 gearbox, the torque T=9550*900/675=12733.3N*m, the carrying torque is much larger than the sand slurry pump. This marine sand pump is suitable for high-concentration sand pumping, the sand output is up to 1,000 cubic meters per hour, and the sand suction pump torque up to 11000N*m. Due to the large torque margin of the diesel engine, the sand extraction pump runs stably, and the customer are very satisfied.
6. Conclusion
The torque plays a crucial role in the sand transfer pump and power system, serving important functions. Here is a summary of the functions of torque in the sand transfer pump and power system:
Providing starting power: Torque is essential for initiating the sand transfer pump. During startup, the pump needs to overcome inertia and resistance, generating sufficient torque to initiate and drive the rotating components of the pump. Adequate torque ensures smooth operation during startup.
Overcoming friction and resistance: The sand transfer pump may encounter friction and resistance during operation, which can adversely affect the pump’s performance and efficiency. By providing enough torque, the pump can overcome these resistances, ensuring the smooth transfer of sand.
Controlling flow rate and pressure: Torque is crucial in controlling the flow rate and pressure of the sand transfer pump. By adjusting the torque, the pump’s speed and output power can be regulated, achieving the desired flow rate and pressure. This is essential for adapting to different working conditions and requirements.
Providing stability and reliability: Proper torque control contributes to the stability and reliability of the sand transfer pump. By ensuring an adequate supply of torque, the pump can operate stably under various workloads and reduce instability caused by load variations or external disturbances.
Energy savings: Optimizing the use of torque can lead to higher energy efficiency. Efficient torque management helps reduce energy waste and improves the overall efficiency of the sand transfer pump and power system.
In conclusion, torque plays critical functions in the sand transfer pump and power system, including providing starting power, overcoming friction and resistance, controlling flow rate and pressure, providing stability and reliability, and enabling energy savings. Understanding and managing torque are essential for ensuring efficient operation and performance of the sand transfer pump.
OCEAN PUMP specializes in the research and development, production and sales of sand pumps, slurry pumps, dredging pumps, mud pumps, sand dredgers and other equipment. Especially has rich experience in dredging, sand mining, and embankment consolidation. OCEAN PUMP has focused on sand pump machine for more than 20 years. We not only provide high-quality products and overall solutions for the industry, but also provide on-site installation services. Please feel free to contact us for plan design and equipment issues related to dredging and sand pumping.
