Prospects for the use of inductor electric gate at ore mills stock company «ALROSA»

Prospects for the use of inductor electric gate at ore mills stock company

Joint Stock Company «ALROSA» is the leader of the diamond industry in Russia (97% of all diamonds in the country), the share in world diamond production — 25%. Probable reserves «ALROSA» make up about one third of world reserves of diamonds. Enrichment facilities are represented by ore factories (№ 3, 8, 12, 14 and 16), Drago (№201, 202 and 203), stationary factories placer (№ 13 and 15), mobile units. The total capacity of processing plant of the company exceeds 32 mln. Tons of processing of raw materials a year. Concentrating factory (PF) № 12 and 14, working as part of the complex, it is currently the largest among similar foreign diamond factories. Established by Russian specialists at the concentrators enrichment technology it is at the level of international standards, and in some technological processes and equipment — it exceeds. On concentrators «ALROSA» is widely used bessharovoe grinding mills using wet autogenous (MMC) domestic and foreign production. Grinding the ore in the MMC is performed by the collision of pieces, and resulting in their falling to the lining of the drum. The enrichment process used fluorescent and sink separation using fluorescent domestic separators, conveyors of various modifications, including vertical, screens, pumps and other equipment with a wide automation. Applied in the factories of enrichment technology and reagents used are environmentally friendly and provide an exception harmful effects on the environment. The leading Russian diamond mining company with the largest open-pit mines in the world is Udachninsky Mining and Processing Plant (GOK), which accounts for the largest volume of diamond mining companies (about 60%). Project annual volume of ore processing at the factory number 12, which is part of the structural unit Udachninsky GOK is 11 million. Tons. This is the most productive factory in «ALROSA», the first phase of which came into effect in 1976. In the management of production and technological processes on the factory uses modern means of automation and computer technology, which provide a clear operation of the equipment and high recoverability diamonds. In recent years the company has undergone great changes in the energy sector. Service chief power accumulated considerable experience in the operation of power equipment. Today the company has successfully introduced modern energy-saving technologies. Since 2002 Udachninsky GOK is preparing for the construction of an underground mine «Lucky» capacity of 4 mln. Tons of ore per year, which will extend the mining Udachninsky field for at least another 50 years. Capacity Udachninsky Mining and processing complex enough to process ore tubes «good» and «Summer lightning» proven reserves of ore Upper Muna group of fields. To the factory could accept and process the ore underground mine, it will be made on reconstruction, will undergo some changes in the technological process.

Rudnik «Aikhal» was put into operation in 1959 in the field of the tube «Aikhal.» Transformed into Aikhal GOK in 1986, with the subsequent increase in production due to the commissioning of a career «Jubilee», which is one of the largest companies and Russian and provide feedstock to 2021 The structure Aikhal GOK includes RP number 8 and 14. The process chain factory number 14 operating at full capacity since 1998, there are three biggest companies in the grinding mills such as MMC (drum diameter of 10.5 m). These dimensions allow the mill to eliminate pre-crushing operation, which is mandatory for commonly used wet autogenous mills. High quality proven reserves and conducting environmental calculations show that the mining of diamonds in the tube «Aikhal» is profitable to a considerable depth. So now here is being built at a fast pace with the release of an underground mine in 2012. The design capacity of 500 thousand. Tons — the prospect of Mining until 2030

Diamond mining has traditionally been a high technology manufacture, which focused modern technology, embodies advanced design solutions. Research and Design Institute Yakutniproalmaz, which is located in the town of Mirny, perform a significant amount of research in the field of mining technology and mineral processing. The Institute acts as the general designer and is the coordinator and generator projects, including the reconstruction of the concentrators and the introduction of energy saving technologies.

On the concentrator number 12 UGOK taking into account the technical condition and a 30-year lifetime is necessary to replace all the wet autogenous mills. The factory is equipped with the penalty bessharovymi MMC family, five of which were delivered by the Japanese company «Roksayl» and two -syzranskim plant «Tyazhmash» .On mills «Roksayl» as asynchronous drive installed high-voltage (6 kV) motors RVF-1F 3300 kW slip ring motors , slip rings, a brush mechanism unregulated speed of 735 min-1 and a starting liquid rheostat, which reduces efficiency. Due to the high rotational speed of the induction motor mill «Roksayl» is equipped with a two-stage step-down gear and a ring gear on the drum, which are in need of more intensive types of grease. The energy performance of the mill «Roksayl»: motor efficiency -0.91; Efficiency of open gear — 0.94; Efficiency of the gearbox — 0.96; Efficiency drum bearings — 0.98; The efficiency of the mill as a whole -0.804.

Drive gearless mills MMC 90-30 Soviet production is a high-voltage synchronous motor SDM 32-24-58-80 (6 kV) with a capacity of 4000 kW and a speed of 75 min-1 (weight 168 tons). It should be clarified that so-called «direct-drive» version of MMC 90-30 presupposes the existence of an open power reducing gear train, driven by a crown whose diameter is about 9 meters mounted on the hub, sitting on the drum shaft (see. Fig. 1b, the gear shaft) . For the selection of the optimal mode of grinding in order to increase safety both diamond mill MSK 90-30 were fitted conversion device PCHVS-4000 / 6.3, which allows to smoothly run the mill and set the desired speed of the engine, and hence of the drum mill. The energy performance of the mill MMC 90-30 as follows: motor efficiency — 0.95; Efficiency of open gear — 0.94; Efficiency drum bearings — 0.98; The efficiency of the mill in general-0.875.

Given the technology of enrichment of diamond ore, regulation of rotation of the drum mill can improve the safety of the natural qualities of diamonds. In 2003, the Institute together with the Institute Yakutniproalmaz IRGIREDMET research was carried out in which conducted the study of influence of the speed of rotation of the drums at the office №12 MMC UGOK on the energy performance of the drive and output products. Tests were conducted at the same time two working mills MMC 90-30 № 4 with a variable speed drive and MMC 90-30 № 5 with a fixed drive. Analysis of the results showed that with decreasing speed drum mills from 80 to 70% of the critical performance of one of the mill feed ore decreased by 7.6% and specific energy consumption for grinding rose by 3.2%. This shows a significant decrease in engine efficiency while reducing speed and load factor. The test results and analysis of sieve specifications of commercial products have shown the influence of the engine speed and thus the drum quality marketable products.

Processing plant number 14 Agok has two mills MMC 105-54 (drum diameter of 10.5 m) with a gearbox factory «Tyazhmash» with the drive ring gear on the drum (Fig. 2) and a similar mill companies «Svedala». MMC 105-54 with two drive gears are equipped with two high-voltage induction motors with wound rotor DAFZ-4000-6-750 capacity of 4000 kW and a speed of 750 min-1. The mill drive «Svedala» with gear and asynchronous motor is N31RXS 900 G6G wound rotor capacity of 5600 kW. After the reconstruction of the MMC 105-54 № 1 in 2003, the problem drive with two drive gears were replaced by odnoprivodny based asynchronous motor N3RXS 900 J / 6 with a wound rotor and liquid rheostat capacity of 7000 kW and a speed 992 min"1 produced by the French company ALSTROM MOTEUDS. At the same stage of reconstruction dvuhprivodnoy MMC 105-54 № 2.

Thus, the disadvantages of the mills of the electromechanical actuator associated with the presence of the bulky gear couplings and bearings of the motor are: the considerable losses of energy (efficiency tract gear less than 90%); The extra space; wear on contacting each other units and parts and hence the cost of their repair; the cost of completion of the lubrication and maintenance of the motor bearings and toothed gear pairs; pollution oil losses and increased fire risk; increased noise and vibration of the electromechanical actuator.

An alternative to the electric gear and so-called «gearless» motors are circular. The world leader in the production of semi-autogenous mills (SAG) with a full low speed gearless synchronous electric drive is the company Metso Minerals (US). Fig. 3 View larger SAG (drum diameter of 11.6 m) with a capacity of 20,000 kW, installed in Chile.

Circular multipole synchronous motors, which are supplied by Siemens (Germany), constructed and placed on the drum as follows. Rotor poles with an excitation winding is bolted to the flange of the drum mill. Stator with three-phase armature winding, which is fed by a frequency converter, embraces elements of the rotor. Thus, the drum mill rotating member becomes large low-speed synchronous motor. The rotational speed of the mill is controlled by changing the frequency of the voltage supplied to the armature winding.

To ring (gearless) electric characteristic: the absence of a mechanical connection between the motor and the mill (hence no friction, wear, loss of heat, and so on. N.); high efficiency (98%) and improved reliability (due to lack of gear); the ability to provide the slow rotation and low feed material to be processed by changing the frequency of the applied voltage, can smoothly change the speed in any frequency range — from 0 to the maximum; control system ensures a smooth start and stop the drive, braking and flexible use of the drive in any desired customer modes of operation of the mill; lack of drive gear system and its lubrication; a small amount of maintenance and a smaller area for installation of the drive.

Gear drives have a capacity ceiling of the order of 7500 kW (about 10,000 hp) per the pinion gear. Gearless electric motor with a ring removes restrictions on the size of the SAG or MMC and its power. The disadvantage of the ring actuator is relatively large initial cost of the development, manufacturing and installation (cost of the drive ring about 30% higher than the cost of the mill).

During the reconstruction of the OB number 12 UGOK four possible options for the replacement of equipment: 1) installation of similar mills MMC 90-30 Russian production (Syzran), equipped with synchronous motors and frequency converters PCHVS; 2) the installation of similar mills «Roksayl» (Metso Minerals), equipped with asynchronous motors and gearboxes; 3) custom design, manufacturing annular valve-inductor motors and purchase mills MMC 90-30 Russian production (Syzran); 4) Custom design, manufacturing annular valve-inductor motors of the mills and the acquisition of Metso Minerals.

The first two options include standard and test procedure for the acquisition of mills and traditional types of engines. For the mills’ Roksayl »Metso Minerals has provided commercial proposals in their manufacture and supply with gear and asynchronous drive. For mills MMC 90-30 also presented technical and commercial proposal of «Tyazhmash» (Syzran) to supply the mills equipped with synchronous motor and SDMZ PCHVS. However, technical solutions applied in the proposed construction of mills and characteristic of the art 70-ies, morally and physically obsolete both in terms of energy, and mechanical.

Alternatively, the drive for mills MMC production «Tyazhmash» and «Roksayl» proposed to use gearless drive with an annular inductor brushless motor (UCI). Development, delivery, commissioning and warranty VIEW will perform JSC «IRIS» (Novocherkassk) using the scientific potential of the South-Russian State Technical University (Novocherkassk Polytechnic Institute) (SRSTU (NPI)). At this point in the negotiation of intent «ALROSA» and ZAO «IRIS» presented technical and commercial proposals for the engines of 2600, 3300 and 7600 kW for the annular actuator respectively the penalty mill MMS 90×30 A «Roksayl» and mills MMC 105 -54 and 750 kW to drive groundwater pumps HRAT-1800. The introduction of a controlled valve drive inductor (VIP) for pumps HRAT dismisses the use of valves and to reduce power losses. Economically and technologically feasible is the use of inductor motors as drives of different pumps on heat supply enterprises of the city (settlement). Electric hoist and the main fan installations are customers of the 1st category of reliability of power supply. One of the necessary conditions for the work of such motors is speed control. Species also differs from common analog engines more reliable.

In accordance with the thematic plan in 2008, the institute has done work Yakutniproalmaz 036-08 / 07, which provides a technical and economic evaluation of the economic effectiveness of the valve-inductor motors for electric MMC concentrators «ALROSA». The paper shows the feasibility and economic efficiency of the inductor valve engine at the concentrators compared with asynchronous and synchronous motors.

From VIP benefits from the technical and economic side, compared to the synchronous and asynchronous motors are the following:

— the most important in terms of energy-saving advantage of VIP is to maintain the high efficiencies of the engine close to the nominal (for large machines 96-98%) in common modes of operation with partial loads on the shaft;

— a higher efficiency of the converter (inverter) by operating at a low frequency of 100-300 Hz unlike inverter induction motor (AM) operating in PWM mode at frequencies above 2000 Hz;

— precision torque control, the ability to control the speed in a wide range during the phase VIP management (improving the processing technology), better soft start and braking (increased service life of the motor windings, gear parts and other elements of the mill and the motor);

— simplicity of design of magnetic stator and rotor coil windings and the motor, without overlapping front parts provides high technology in manufacturing, increased reliability, and low failure rate, durability and serviceability (reduction of costs for repairs and maintenance);

— the rotor has no windings, rotor losses become small, so it is not required heat removal;

— enhanced survivability ID is provided by the magnetic independence of the phase windings in the motor and electrically independent phase of blocks in the frequency converter, so any damage to one or more of the phases does not lead to a complete loss of drive efficiency is reduced only by its capacity;

— no gearbox (no cost for the replacement of oil and eliminated component reduces the overall efficiency of transmission);

— released production area that gives an advantage in the reconstruction of the plant.

From the Company «IRIS» is also investigated the possibility of using as a drive TYPE MMC PF. It should be noted that the development of JSC «IRIS» based on the experience of almost fiftieth nauchnopedagogicheskoy School of Electrical SRSTU (NPI). On the topic of inductor machines and their electronic management defended fourteen candidates and two doctors of science. This is a respectable school, which tend to work with not only domestic, but also foreign companies, organizations and universities. In this paper, based on the experience of the Novocherkassk electrical scientific school in the field of inductor machines expediency and the ability to create energy-efficient and reliable traction valve inductor electric high power, which, without doubt, will be used primarily as an electric traction locomotives, heavy-duty dump trucks and trains , tractor trucks and excavation equipment in the system of electric propulsion surface ships and submarines, as well as in electric and other purposes. At the present time, taking into account the successful experience of introduction of the VIP support from 1.1 to 32.5 kW at the facilities of the Russian Navy and tests VIEW 500 kW Company «IRIS», with the assistance of scientists SRSTU (NPI) actively conducts scientific researcher and project-cal design work on the creation of the view from the frequency to 20 preobrazovatelyamimoschnostyu LLC kW at low speeds, which do not require the use of gear units. Drive efficiency is 96-98%. In 2009, the company will supply gearless electric drive for small marine tug rowing VIEW power 2000 kW and a speed of 200 min-1 (motor weight 30t).

According to the agreement on cooperation of JSC «IRIS» and «ALROSA» were carried out preliminary design work on the creation of low-speed ring view for MMC and concentrators Udachninsky Aikhal GOK and formed tehnikokommercheskie proposal. The construction of five-phase annular form for the autogenous mill drive diamond ore MMC 90-30 shown in Fig. 4 a, a circular design view of the drum of the mill «Roksayl» -on Fig. 4b.

the stator fastening part. As a support for the rotor drive motor SAG mill diamond ores applied sleeve 5 driven toothed crown gear of the mill, and the stator portion of the motor 6 is fixed by means of clutches on the base of the mill, with a gap spanning part of its rotor. With the engine coil winding turns of each phase provides a control voltage pulses of rectangular shape of five-phase half-bridge inverter voltage. Operating the magnetic flux passes through magnetic toothed stator 7, the working air gap of the magnetic core and the toothed rotor 4 creates an electromagnetic torque contactlessly acting on the teeth of the rotor part of the magnetic circuit and through the hub and the ring gear shaft mill drum, causing it to rotate.

Gearless reduces the amount of space occupied by the length of the mill is about twice eliminate polluting oil losses, significantly reduce the fire hazard. In addition, in the proposed actuator is no contact between the components and parts, such as bearing assemblies of the motor and gearbox, gear pairs, which improves the reliability of the drive, to significantly reduce power losses due to the absence of friction and increase the drive efficiency by 8-9% as well as significantly reduce the noise (including infrasound range and high-frequency components) and the vibration actuator and eliminate the cost of maintenance and repair of wearing contact nodes.

For a number of advantages (simple structure, a low cost, reliability and maintainability, the best energy performance) VIP obviously can compete with controlled asynchronous electric engines of industrial application, which are replacing DC drives.

However, some circumstances prevent the active promotion of the VIP market. Despite the fact that the cost of AD is higher than the species under mass production they are in the market less than inductor motors manufactured to order. The same applies to the inverters napryazheniya.Trёhfaznye bridge inverter which 1foizvodyatsya series also cost less than the half-bridge, which used to supply and control the view from the bathroom with the armature winding and the excitation (inductor jet engine or a self-excited).

One of the options on the way forward view of the market is its adaptation for the power bridge inverter. The Company «IRIS» proposed and approved scheme of power and control from the bridge inverter dvuhpaketnogo view from the two three-phase windings, ectopic space 180 e. hail, (six-phase machine), is protected by a patent. This engine of positive pulses through diodes powered three-phase winding one, but on the negative — out of phase in time for the 180 e. deg., — other.

Compared with the three-phase view from one winding, which is powered by a half-bridge inverter, the proposed variant has reduced torque ripple, twice the power factor and saves power cable. The view from the two three-phase windings can be performed not only in dvuhpaketnom, but in odnopaketnom (nizkooborotaye) versions. Odnopaketnoe execution of six-phase VIEW compared with dvuhpaketnym has smaller weight and size characteristics and higher efficiency. On construction odnopaketnogo view from two three-phase windings and the patent.

On the PF number 12 UGOK semiconductor converters that feed the engines driving pumps HRAT-1800, located approximately 40 m from the pump, so for practical implementation was selected VID-powered bridge converter with three-phase trёhzhilnogo cable.

Currently, the elaboration of JSC «IRIS» is a perspective view from the version of the ring magnetically independent autonomous U-shaped element of the stator core, which also realized the possibility of supply from three-phase inverter bridge voltage. Motor windings are connected in treugolnik.Pri excitation of the electromagnet, ie, supplying current in its windings, the rotor teeth are drawn to the magnetic field, which creates the torque. By alternately driving the respective electromagnets of the stator, which run over the teeth of the rotor provides a continuous rotation of the rotor. In order to avoid any braking torque at the electromagnets, from which escape the teeth of the rotor, the current is switched off. By varying the frequency of excitation of the electromagnets changing the rotor speed and, accordingly, the drum mill. Note that in this car inductor excited simultaneously at least three of the six phase electromagnets on the station phase zone. This provides a small torque fluctuation.

The proposed design of the ring Split view from the stator elements of the technology greatly simplifies installation and reduces its weight of electrical steel. Feeding a perspective view of windings can be realized by several bridge inverters, each of which independently supplies phase coils of two diametrically opposite zones the annular TYPE phase that provides improved system reliability and high power failure it remontoprigodnost.Vyshedshy semiconductor converter may be disconnected without loss of drive performance .

Conclusions:

1. Upgrading concentrators «ALROSA» should be carried out taking into account the modern scientific and technological level of development in the field of electrical engineering, power electronics and microprocessor technology.

2. Valve inductor drive is currently one of the most advanced, technically and economically feasible options to ensure effective modernization of equipment concentrators «ALROSA».

3. If you select execution of large-sized annular valve engine of high power inductor should consider not only the energy and mass and dimensions, but installation and adaptability, as well as issues of high reliability and maintainability of his work.

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