外文翻译21世纪前半叶矿井提升机在深井中的应用.doc
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1、英文原文Mine hoisting in deep shafts in the 1st half of 21st Century Alfred Carbogno 1 Key words: deep shaft, mine hosting, Blair winder, rope safety factor, drum sizing, skip factor Introduction The mineral deposits are exploited on deeper and deeper levels. In connection with this, definitions like “d
2、eep level” and “deep shaft” became more and more popular. These definitions concern the depth where special rules regarding an excavation driving, exploitation, rock pressure control, lining construction, ventilation, underground and vertical transport, work organization and economics apply. It has
3、pointed out that the “deep level” is a very relative definition and should be used only with a reference to particular hydro-geological, mining and technical conditions in a mine or coal-field. It should be also strictly defined what area of “deep level” or “deep shaft” definitions are considered. I
4、t can be for example: - mining geo-engineering, - technology of excavation driving, - ventilation (temperature). It is obvious that the “deep level” defined from one point of view, not necessarily means a “deep level” in another area. According to 5 as a deep mine we can treat each mine if: - the de
5、pth is higher than 2300 m or - mineral deposit temperature is higher than 38 C. It is well known that the most of deep mines are in South Africa. Usually, they are gold or diamonds mines. Economic deposits of gold-bearing ore are known to exist at depths up to 5000 m in a number of South Africa regi
6、ons. However, due to the depth and structure of the reef in some areas, previous methods of reaching deeper reefs using sub-vertical shaft systems would not be economically viable. Thus, the local mining industry is actively investigating new techniques for a single-lift shaft up to 3500 m deep in t
7、he near future and probably around 5000 m afterwards. When compared with the maximum length of wind currently in operation of 2500 m, it is apparent that some significant innovations will be required. The most important matter in the deep mine is the vertical transport and the mine hoisting used in
8、the shaft. From the literature 1-12 results that B.M.R. (Blair Multi-Rope) hoist is preferred to be used in deep mines in South Africa. From the economic point of view, the most important factors are: - construction and parameters of winding ropes (safety factor, mainly), - mine hoisting drums capac
9、ity, This article of informative character presents shortly above-mentioned problems based on the literature data 1-12. Especially, the paper written by M.E. Greenway is very interesting 3. From two transport systems used in the deep shaft, sub-vertical and the single-lift shaft systems, the second
10、one is currently preferred. (Fig.1.) 6 Hoisting Installation The friction hoist (up to 2100 m), single drum and the double drum (classic and Blair type double drum) hoist are used in deep shafts in South Africa. Drum winders Drum winders are most widely used in South Africa and probably in the world
11、 Three types of winders fall into this category - Single drum winders, - Double drum winders, - Blair multi-rope winders (BMR). Double drum winders Two drums are used on a single shaft, with the ropes coiled in opposite directions with the conveyances balancing each other. One or both drums are clu
12、tched to the shaft enabling the relative shaft position of the conveyances to be changed and permitting the balanced hoisting from multiple levels The Blair Multi-Rope System (BMR) In 1957 Robert Blair introduced a system whereby the advantage of the drum winder could be extended to two or more rope
13、s. The two-rope system developed incorporated a two-compartment drum with a rope per compartment and two ropes attached to a single conveyance. He also developed a rope tension-compensating pulley to be attached to the conveyance. The Department of Mines allowed the statutory factor of safety for ho
14、isting minerals to be 4,275 instead of 4,5 provided the capacity factor in either rope did not fall below the statutory factor of 9. This necessitated the use of some form of compensation to ensure an equitable distribution of load between the two ropes. Because the pulley compensation is limited, B
15、lair also developed a device to detect the miscalling on the drum, as this could cause the ropes to move at different speeds and so affect their load sharing capability. Fig.2 shows the depth payload characteristics of double drum, BMR and Koepe winders. The B.M.R. hoist is used almost exclusively i
16、n South Africa, probably because they were invented there, particularly for the deep shaft use. There is one installation in England. Because of this hoists physical characteristics, and South African mining rules favouring it in one respect, they are used mostly for the deep shaft mineral hoisting.
17、 The drum diameters are smaller than that of an equivalent conventional hoist, so one advantage is that they are more easily taken underground for sub-shaft installations. A Blair hoist is essentially a conventional hoist with wider drums, each drum having a centre flange that enables it to coil two
18、 ropes attached to a skip via two headsheaves. The skip connection has a balance wheel, similar to a large multi-groove V-belt sheave, to allow moderate rope length changes during winding. The sheaves can raise or lower to equalize rope tensions. The Blair hoists physical advantage is that the drum
19、diameter can be smaller than usual and, with two ropes to handle the load, each rope can be much smaller. The government mining regulations permit a 5 % lower safety factor at the sheave for mineral hoisting with Blair hoists. This came about from a demonstration by the% permits the Blair hoists to
20、go a little deeper than the other do. On the other hand, the mining regulations require a detaching hook above the cage for man hoisting. The balance wheel does not suit detaching hooks, so a rope-cutting device was invented to cut the ropes off for a severe overwind. This was tested successfully bu
21、t the Blair is not used for man winding on a regular basis. The B.M.R. hoist has been built in three general styles similar to conventional hoists. The three styles are (Fig. 3 and 4): The gearless B.M.R. hoist at East Dreifontein looks similar to an in-line hoist except that the drums are joined me
22、chanically and they are a little out of line with each other. This is because each drum directly faces its own sheaves for the best fleet angle. The two hoist motors are fed via thyristor rectifier/inverter units from a common 6.6-KV busbar. The motors are thus coupled electrically so that the skips
23、 in the shaft run in balance, similar to a conventional double-drum hoist. Each motor alternates its action as a DC generator or DC motor, either feeding in or taking out energy from the system. The gearless Blair can be recognized by the offset drums and the four brake units. A second brake is alwa
24、ys a requirement, each drum must have two brakes, because the two drums have no mechanical connection to each other. Most recent large B.M.R. hoists are 4.27 or 4.57 m in diameter, with 44.5 47.6 mm ropes 1. In arriving at a drum size the following parameters have been used: - The rope to be coiled
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