Gearless mill drives
pinion, gearbox, coupling, motor shaft and motor bearings, used within a conventional mill drive system. By mounting the rotor poles directly onto the mill, the mill itself becomes the rotor of the gearless motor. Building a track record ABB's experience in optimizing gearless solutions for grinding applications extends over 50 years,
TECHNICAL AND COMMERCIAL BENEFITS OF …
The first Gearless Mill Drive (GMD) with a power of 6.5 MW was installed 1969 in a cement milling process in the cement plant Le Havre in France. In the first few years, the GMD was only used in the cement industry. The GMD is also known as …
gearless mill drives Archives
The $1.2 billion expansion, which saw throughput rise from 60,000 t/d to 120,000 t/d, involved the addition of two new thyssenkrupp-made ball mills, with ABB providing the gearless mill drives (GMD) technology. This came on top of the 33 mills the miner already had up and running as part of the existing 60,000 t/d plant at the operation.
Ring gear drives huge grinding mill | Machine Design
Ring-motor drives were first used in cement industry mills and later in mining industry applications. The largest ringmotor- driven mill in the world is a 36-ft diam., 16,000-hp SAG mill that ...
Grinding | ABB
More powerful and larger mills, higher ball charges and demanding ambient conditions call for a strong partner for grinding solutions. We help you meet these challenges with our drive systems that come with a long …
SOPHISTICATED RING GEARED MILL DRIVES: FEATURES …
The electrical drive system configuration consists of a three winding, a converter transformer, an ACS 6000 multidrive medium voltage frequency converter and two …
Gearless mill drives
Our GMD eliminates all mechanical components of a conventional mill drive system, such as ring-gear, pinion, gearbox, coupling, motor shaft and motor bearings: By mounting the rotor poles directly onto the mill, the …
Large AC Adjustable Speed Motors for Metals Rolling …
Introduction. AC adjustable-speed motor drive systems have been established as the preferred. technology for new rolling mill installations and extensive modernization projects. The AC adjustable-speed motor drive system provides metals mills with many advantages compared to traditional DC drive technology, including: Improved drive effi ciency.
Solids | Choose the Right Grinding Mill
2. Don't choke the mill by starting with solids content that's higher than the mill can process. A rule of thumb is to start with 50% solids and adjust as needed. Remember that as particle size is reduced surface area and viscosity will increase, which may require lowering the percent solids.
SIMINE Gearless mill drives
mill-motor interface is a multifaceted task, a procedure ... Electrical equipment and automation of a drive system Larger grinding mills are at the heart of every grinding section. Stringent demands to achieve high throughput, highest availability, optimized grinding circuits and power consumption optimization require high-performance
Literature Review: Gearless Motor Failures – A Mill Designer…
In [1], Svalbonas reviews the states-of-the-art in the design of grinding mills and ring-motors (for gearless drives). He concludes that failures in ring motors occurred because the structural design of these motors had not been validated through measurement. Svalbonas expresses his hope that gearless drive manufacturers will …
Demystifying The Sag Mill: What Is It And How Does It Work?
The motor is a vital component of a SAG mill as it provides the necessary power to rotate the mill and drive the grinding media. The motor is connected to the mill through a power transmission system, which typically consists of gears, couplings, and a gearbox. The power transmission system ensures that the motor's rotational energy is ...
(PDF) Twin Synchronous Motor Grinding Mill Drives: …
1.0 Introduction In large grinding mills such as the mineral and cement industries where twin motor drives ... 1.0 Introduction In large grinding mills such as the mineral and cement industries where twin motor drives are used, the two major challenges which limit the use of two synchronous motors connected direct on line and mechanically ...
TWIN SYNCHRONOUS MOTOR GRINDING MILL DRIVES: …
1.0 Introduction In large grinding mills such as the mineral and cement industries where twin motor drives are used, the two major challenges which limit the use of two synchronous motors connected direct on line and mechanically coupled to the same mill are motor overheating – due to the fact that the two motors do not share the mill load …
Electric Drives for Large Ore Grinding Mills
The mill operating speed of a geared drive is usually fixed by a constant speed motor and must be preselected. That speed decreases as the mill diameter increases, thereby increasing the transmission and drive problem. Since speed has such an effect on grinding, production, mill wear, and resultant costs, it must sometimes be …
ABB Library
The grinding process with one 34' x 20' SAG mill and two 24' x 39.5' ball mills will be briefly discussed. All three mills are gear driven by a ring gear, dual pinion and two low speed synchronous motors. Copper Mountain has installed on all three mills, the new state-of-the art dual pinion mill drives.
Ring-geared mill drives
Ring-geared mill drive system. High performance and flexibility in grinding. Decreasing global mineral resources, exploitation of lower ore grades in more remote locations and extreme environmental conditions …
Products and solutions Drive systems for all grinding
Products and solutions. Drive systems for all grinding applications. A comprehensive portfolio for optimal results. More powerful and larger mills, higher ball charges and …
Mill drive selection for semiautogenous grinding mills
ball mills, 18x27 drive with an air clutch, motor, $602,000 6050 E Primary SAG, 34x1 6 Two variable speed ac motors coupled mill, $4 million 22,500 to a gear drive with air clutches. motor, $1.75 million each 6000 Two secondary ac synchronized motor coupled to a gear mill, $2.5 million ball mills, 18x27 drive with an air clutch. motor, $602,000 ...
Autogenous mills, semi-autogenous mills and ball mills …
xIdeal for ring motor drives. Polysius grinding mills can be driven via ring gear pinion drives or the COMBIFLEX® drive for drive capacities of up to 16,000 kW. Higher drive power is reliably transmitted via ring motor drives. Polysius standard range of grinding mills Polysius has established a standard for grinding mills, which
STEPPING FORWARD: USING VARIABLE SPEED …
after which everything is ready to drive the mill. Once the "variable speed solution" is chosen, an important decision to be made by the operator is left referring to the motor: whether to opt for a high speed or low speed solution. Gear driven mills can be motorized both with the high speed solution or the low speed solution.
Paper # 25
Mill type Wet grinding, grate discharge Mill drive motor size 17,000 HP Mill drive motor type Synchronous 200 RPM Inside diameter 10,363 mm Length 6,096 mm Effective grinding length (EGL) 5,334 mm Bearing type Partial Journal, 120 degree bronze insert Bearing size 2,950 mm diameter by 660 mm wide Bearing material Bronze
The Siemens 42ft gearless mill drive, still an …
The result is the design of a Gearless Mill Drive motor for a 42ft Grinding Mill providing up to 35MW of power. Evolution is still the main GMD design philosophy, but realistic and proven computer models help to look beyond experience, where testing is impossible. The Siemens 42ft gearless mill drive, still an evolutionary design approach?
Updates on geared vs gearless drive solutions for grinding mills
With successful operation of 2 x 6.5MW (Phu Kham, Laos) and three 2 x 7MW units under manufacture (Pascu Lama) and a further 40 projects worldwide, energy efficient Hyper Synchronous SER drives are now mature and ready for use on 2 X 10MW dual drive mills. Speed variation required is in the range of +/- 15% of synchronous motor speeds.
Design and dynamic behavior of large Ring Motors for …
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Load Sharing of Dual Motor Grinding Mill Drives
Relatively small slowly varying shaft position and velocity variations superimposed on the normal running speed of dual drive grinding mill motors can cause individual motor torque variations which disturb load sharing. The magnitude of load or torque unbalance is a function of the magnitude of the mechanical variation, the type of motors used, i.e., …
The future of vertical roller mill drive systems
The trend to larger grinding mills with the attendant increase in motor drive horsepower has affected the options for drive equipment. Also the development of large adjustable speed drives has ...
Technical evaluation and practical experience of high-power grinding …
Most of these mills are driven by adjustable-speed drive 2000 m (6000 ft) above sea level; synchronous machines, connected to cycloconverters or load- 3) low-frequency output, because large diameter grinding commutated inverters (LCIs) controlling the motor speed and mills must rotate at variable low speeds, in the range from torque [2], [8].
Solutions for the Mining Industry
Application 1. Grinding Mill Systems Grinding mills are crucial to mineral processing operations. As lower quality ore bodies are tapped, the tonnage processed per ounce of salable material will increase. This degradation in ore quality requires more power in the mill circuit, meaning larger motors and drives.
Increasing availability through advanced Gearless Drive …
The comparison of a conventional drive train to a gearless drive for a grinding mill is shown in figure 1. Figure 1 – Top view of SAG mills with alternative drive options; left …