Gearboxes are frequently used in the mining industry, especially for power transmission between the electric drive and the ball mill; besides the extreme complexity of a ball mill gear transmission system, the fault diagnosis by vibration analysis can be easily distorted by the presence of impulsive noises due to the ball pulses on the mill shell. Although several works in the literature are ...
WhatsApp: +86 18203695377torque speed curves ball mill vfd motor | ® Crusher . is the best torque speed curves ball mill vfd motor . main products includes mobile crusher,jaw . speed and torque. . you get a new torque curve. ... Hot Products Used for ball mill load torque curve pew jaw crusher scm ultrafine mill hpc cone crusher cs cone . torque speed ...
WhatsApp: +86 18203695377The use of VSDs makes it very easy to set the mill speed by just modifying this value on a touchscreen. But this is not only an option for new installations. In installations where SAG and Ball mills have been working for several years at fixed speed, but the speed regulation has been observed to be necessary VSDs can also be integrated very ...
WhatsApp: +86 18203695377The approximate horsepower HP of a mill can be calculated from the following equation: HP = (W) (C) (Sin a) (2π) (N)/ 33000. where: W = weight of charge. C = distance of centre of gravity or charge from centre of mill in feet. a = dynamic angle of repose of the charge. N = mill speed in RPM. HP = A x B x C x L. Where.
WhatsApp: +86 18203695377The results obtained from simulations and subsequent torque data processing show the possibility of characterizing the load torque of ball mills in the frequency domain without the influence of components alien to the grinding process. In this paper, it is shown that load torque signal in ball mills contains enough information to characterize ...
WhatsApp: +86 18203695377Power drawn at the pinion is 448 kW, kWh/tonne (SAG mill) and 570 kW, kWh/tonne (ball mill) when processing mtph, for a total of kWh/tonne or % above the conventional estimate. A ball charge volume which is lower than those tested has been selected in order to minimize wear.
WhatsApp: +86 18203695377The starting torque characteristic of this type of ball mill is not linear. Figure 2 shows the graph of mill speed versus torque requirement: Figure 2 The graph clearly shows that the torque requirement exceeds 120% at 80% speed. This is why the starting torque of the drive motor should be at least 130% of full load torque.
WhatsApp: +86 18203695377The SMCPMSM is wrapped on the ball mill to realize direct drive, which eliminates the torque transfer part such as the reduction box and gear in the traditional drive mode to improve transmission ...
WhatsApp: +86 18203695377Very little torque is normally required at 0 speed. (See Fig. 4.) Fig. 3 Load SpeedTorque Curve A motor having high LRT, such as defined by the National Electrical Manufacturer's Association (NEMA) for Design C on small motors, or large motors with less exaggerated high torque curves, will normally have a large dip in torque in the 5080%
WhatsApp: +86 18203695377The power, which is given by the product of this torque curve with the mill speed, has a much rounder peak centered on N= before dropping sharply for higher rotation rates. For a mill operating at a typical 80% of critical, the power predicted by the model is 3×10 5 W/m of mill length. For a typical 7mlong mill, the power required is ...
WhatsApp: +86 18203695377fies a higher rated speed of the mill will get a lower torque design, usually resulting in a lower motor cost. The paper specifically describes SAG mills, but the equations and principles apply equally to any conventional tumbling mill, such as AG, ball or rod mills. The engineering and process effects of choosing a motor design speed
WhatsApp: +86 1820369537712. Pullin Torque curve (inertial load): This curve represents the maximum torque and speed combination that a stepper motor with an inertial load ( damper) can supply to a load and start or stop without any acceleration or deceleration. In order to operate above the pullin torque curve, the motor must be accelerated into or decelerated ...
WhatsApp: +86 18203695377Figure 1. The torque curve and power curve for a constanttorque spindle. Figure 2 shows the torque and power curves for a spindle motor with constant torque followed by constant power. This kind of design is more common for spindles intended for use in the lower speed range, and, typically, the torque is higher.
WhatsApp: +86 18203695377At the stage of starting of ball mill, load torque, rotary inertia and so on could be acquired. ... break and it quickly followed by other particle in the top curves and form a sliding stream ...
WhatsApp: +86 18203695377The aim of this paper is to present a method to analyze the dynamic of the charge in a ball mill. The method is based on the mill torque estimated from angular position and motor electrical signals. The estimated torque signal obtained from a Luenberguer velocity observer is bandpass filtered to isolate the millfillingrelated component. The rootmeansquare value of this component, used as ...
WhatsApp: +86 18203695377Torque mill solids load during test: kg ( lb) of ball mill feed sample from plant survey. Sample is reconstituted with water to be the same percent solids as the plant ball mill discharge. Mill speed: rpm (65 percent of critical speed) Length of time of test: 363 seconds Average torque reading: 1,056 inlbs Mill HP = (1,056 in ...
WhatsApp: +86 18203695377Step 2: Get a handle on horsepower. The rule of thumb for motor horsepower is: Select only what you need, and avoid the temptation to oversize or undersize. Calculate the required horsepower from this formula: Horsepower = Torque x Speed / 5250. Where torque is in lbft and speed is in rpm.
WhatsApp: +86 18203695377We can calculate the steel charge volume of a ball or rod mill and express it as the % of the volume within the liners that is filled with grinding media. While the mill is stopped, the charge volume can be gotten by measuring the diameter inside the liners and the distance from the top of the charge to the top of the mill.
WhatsApp: +86 18203695377the ratio of the area underneath the motor torque curve during acceleration to the area between the motor and load torque curve during accelera tion. For typical ball mills this starting torque ...
WhatsApp: +86 18203695377Haas Torque and Power Charts ES0088M Rev BR 1/29/2016 Page 1 Page Contents 2 Tool Room Mill and Mini Mill Spindle 3 Super Mini Mill Spindle. 4 Super Mini Mill 15K Spindle 5 VF Standard, UMC Inline Spindle: ... 150% spindle load (75% of the peak number) for 15 minutes, spindle load (50% of the peak number) continuously. ...
WhatsApp: +86 182036953771. Introduction. Grinding is an industrial process that accounts for a large proportion of the mineral processing industry [1], SAG mill is the main mining equipment in this main working device of the SAG mill is a drum that is placed horizontally and can be rotated, the lifters are provided on the inner wall of the drum that includes the cylinder face and the end faces on both sides.
WhatsApp: +86 18203695377According to the Morrel powerdraw model (Morrell, 1994), the mill powerdraw, P Gross, is as follows: The noload component of the mill powerdraw, P N o Load is, The mill pulp density, ρ p, is ...
WhatsApp: +86 18203695377The torque speed curve of a load is a plot showing its torque requirement on the yaxis versus the speed on xaxis. It's the torque requirement of the load from zero speed to full speed. Its application/load specific and varies with different load types. Loads like centrifugal pumps and fans follow quadratic speed torque curve, where
WhatsApp: +86 18203695377The drum diameter is m, so if the maximum load (including the cable) is say 1000 kg, the tension in the cable (mg) will be 9810 N, and the torque applied by the load at the drum will be given by Force × radius = 9810 × ≈ 2500 Nm. When the speed is constant ( the load is not accelerating), the torque provided by the motor at the drum must be equal and opposite to that exerted ...
WhatsApp: +86 18203695377The mill power draw models are used to predict how much power will be consumed by a particular type of mill, mill geometry and set of mill operating conditions. This power is transferred to the ore and used to predict the throughput when combined with the specific energy consumption models. Models of this type do not predict the particle size ...
WhatsApp: +86 18203695377valve torque. The initial ball/seat torque of the valve is results of the seats preload (determineby the designer), and the seat material. The relative high friction arias, together with the floating ball design concept,which allows the system pressure to force the ball into the downstream seat, cause the Ball/seat torque to be very sensitive to
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