Which of the following motors are best for the rolling mills? A. Single phase motors. B. Squirrel cage induction motors. C. Slip ring induction motors. D. D.C. motors.

SAG mills are also an optimum solution for wet grinding since crushing and screening in these cases can be difficult, if not impossible. Efficiency through automatic operation. Outotec's process engineers will assist you in creating an efficient software-driven process, from circuit design to start-up and optimization, to ensure you get ...

•Select motor(s) to fit the mills. Step 1: Mill overload power •Determine a set of operating conditions that reflects the maximum "overloaded" condition that the mill should be able to handle: –SAG mills: 20% v/v ball charge, 30% v/v filling and 78% critical speed with worn liners –Ball mills: 36% v/v …

SAG mills grinding media includes some large and hard rocks, filled rate of 9% – 20%. SAG mill grind ores through impact, attrition, abrasion forces. In practice, for a given ore and equal processing conditions, the AG milling has a finer grind than SAG mills.

30 July, 2013. ABB is buying Alstom's ring motor business to enhance its gearless mill drive (GMD) activities. The business, based in Bilbao, Spain, has about 120 employees and achieved a turnover of €57m in 2012/13. It will become part of ABB's Process Automation division. The financial details of the deal have not been revealed.

wound rotor motor is not the best option for SAG mills becuse the slip rings always are a problem even with liquid resistors.Best option is synchronuos motor in combination with variable frequency drive.However if you already have the wound rotor motor the ERS operation is simple.

Ring Motors vary the speed of the mill by changing the sta-tor frequency. A cycloconverter provides variable frequency for start, stop and speed variation during operation. Figure 1: Ring Motor of the 38' SAG-Mill of Rio Paracatú Mineraçao; Brazil 3 Design Verification To assure reliability of operation the mechanical design must be verified.

inching drive for sag mill. inching drive for sag mill. As a professional crushing and grinding equipments manufacturer, …. Complete with 250 KW Drive … 5250 Morgardshammer Ball Mill: ….

The motor's slip rings & brush gears, critical components on any wound rotor machine are rated for continuous operation and are fitted with highly reliable brush - lifting & short-circuiting devices.The unit's high quality carbon brushes feature a large cross- sectional area to better conduct high currents safely during heavy peak load conditions.

SAG mills of comparable size but containing say 10% ball charge (in addition to the rocks), normally operate between 70 to 75% of the critical speed. Dry Aerofall mills are run at about 85% of the critical speed. ... for the 20 MW ring motor alone exceeding A$1M. …

Slip Ring Motor MCQ Question 10: In a 3-phase slip-ring induction motor, the slip at some speed is 0.05. The speed is reduced by inserting an external resistance in the rotor circuit and the slip is 0.15. If the rotor winding resistance per phase is 0.2 Ω, the external resistance is. 0.2 Ω.

The disadvantages are that the D.C. motor, tends to be inefficient, and also tends to have a poor lagging power factor. Capital cost of a variable speed motor is higher than a fixed speed motor, but the biggest disadvantage of utilizing a D.C. motor, as a general rule of. Variable Speed SAG Mills Motor Capability vs Mill Capability

Pinions Geared Rings Ball Mills and spares SAG Mills and spares Crushers and spares Buckets and teeth Support Rollers Lower, Upper, Bottom shells Infocenter SAG is an acronym for semi-autogenous grinding. SAG mills are autogenous mills that also use grinding balls like a ball mill. A SAG mill is usually a primary or first stage […]

Outotec called on its Field Services and A&CA teams to meet the challenge of changing out the main motors for the SAG ball mills at the underground site of the state miner in under 2 months. Located in the Valparaíso region, Andina stands out for being Codelco's division with the highest copper mineral reserves in the country, combining ...

Most of our work since 2000 has been in developing grinding mill foundations to avoid vibration and unacceptable deflections. On a recent project for a plant in Peru, the client was told by the mill vendor that there was no need to do a systems (dynamic) analysis on the mill foundations because the mills on that project were gear driven rather than being driven by ring motors (gearless drives).

The principal component of the new drive system, which was designed and constructed within just two years, is a ring motor with a width of 25 meters and a height of 20 meters. 38-foot SAG mill with gearless drive system from Siemens.

for induction and synchronous motors in single- and dual-pinion configurations. These drives are well-suited for all type of mills and ball mill ap-plications, and are able to cover the power range up to the mechanical limit of the gearbox or the ring gear. The solution provides ad-justable speed for AG and SAG mills, or the opportu-

Advantages of SER drives for SAG mills. Friday, December 19, 2014 ... So for a fixed torque and higher speed, the power obtained from the motor is higher than the motor nameplate rating. Brush/slip ring maintenance is one issue. However, when the brushes are specified correctly for the load, the wear is manageable. ...

1. SAG mill is the primary tool for grinding. SAG mill is used before the other mills. Ball mill is a secondary, and it is used after the SAG mill. 2. SAG mill breaks the raw material into pieces for the further grinding. Ball mill is used to grind the pieces of raw material into. powder-like structures. 3.

The standard inching drive motor is a NEMA or IEC frame typically foot mounted to a motor scoop or base plate. Typical motor speeds are either 4 or 6 pole, i.e. 1750 rpm or 1170 rpm for 60 Hz applications and 1450 rpm or 970 rpm for 50 Hz applications. The advantage of using a four pole motor allows for a smaller footprint and a smaller brake if

autogenous grinding (SAG) mills, or ball mills. The most important components of a GMD are the following ones: The stator is a massive electro-mechanical structure built around the grinding mill, hence its alternative names "wrap-around motor" and "ring motor" (see Figure 1). Its purpose is to

The Siemens 42-ft Gearless Mill Drive, still an evolutionary design approach? (SAG Conf. 2015) Optimization of the drive system for a cyclone feed pump (SME 2015) Increasing availability through advanced Gearless Drive Technology (CMP 2014) Design and dynamic behavior of large ring motors for grinding mills (SMMH 2012)

cement industry. The GMD is also known as "wrap-around motor" or "ringmotor". Almost 25 years later, the first GMD with 12.0 MW power and 13.0 rpm was installed in the minerals industry. Since then, numerous GMDs for ball mills and SAG mills have been installed in the minerals industry. The main advantages are that the GMD is

Wound rotor induction motors (WRIM) have been popular for decades in the cement and mining industry for starting and driving large grinding mills. In fact, until about 1985, a wound rotor induction motor was the only large ac motor that controlled starting characteristics and adjustable speed capability. Stator R ot r Slip Rings 3-Phase stator

Electric Maintenance / Control and specialized technical Assistance SAG Mills Ring Motors. Aug-2004 - Active CUSTOMER TYPE OF SERVICE YEARS Codelco, División Norte - Concentrating Plant A2 Electric Maintenance / Control and specialized technical …

ABB's contact called for delivery of four dual pinion low-speed mill drive systems for two semiautogenous (SAG) and two ball mills, each consisting of two synchronous motors, converter transformers and ACS6000 frequency converters including active rectifier units that allow the mill drives to achieve a power factor of 0.90 leading.

Gearless Warp Around SAG Mill. For almost a decade now, very good operating experiences have been gained with a total of 28 gearless ring motor drives in the cement industry, driving tube mills with diameters of 2.5 to 4 meters with drive powers ranging from 3000 to …

SKU: L02040. Category: Grinding Mills. Description. Description. 21′ x 11′ Hardinge SAG mill with 2875 DC slip ring motor, inching drive, & lubrication located …

The motor power, so far, can go up to 28 megawatts for such an application. An infographic of the ring motor and further visual materials can be found here. Raw material from the crushing stage is typically fed to SAG (semi-autogenous), AG (autogenous) and ball mills for further processing to break the rock into smaller pieces.

The motors are being applied in pairs to SAG and ball mills that operate through dual pinion drives supplying power to each mill. Historically, WEG says the customer was facing problems for a number of different reasons such as mechanical …