Mining and transportation of minerals is an important link in the process of mineral production. As the key equipment for mine transportation, mine hoists are responsible for the lifting of coal and ore, the lifting of personnel, and the transportation of materials and equipment. They are important equipment that connects the underground and the ground. .

my country's coal reserves are extremely rich and rank among the top in the world. It is a guarantee energy source for the sustainable development of my country's economy and plays a leading role in my country's energy system. The annual production volume of mine hoists in my country is mainly related to the demand for coal mines, especially large and super large mine hoists.

1　The development of domestic hoist

The design and manufacture of lifting equipment in my country was originally imitated the former Soviet Union, and then developed to self-design and manufacture. In 1953, Fushun Heavy Machinery Factory manufactured my country's first single-rope twin-cylinder hoist. In 1958, Luoyang Mining Machinery Factory designed and manufactured my country’s first well tower JKM2×4 multi-rope friction hoist. In 1960, it designed and produced another well tower JKM3×4 multi-rope friction hoist. Formed mass production capacity and got rid of the situation of relying on imports.

Since the 1970s, the structural defects of imitation hoists have become increasingly prominent. Luoyang Mining Machinery Factory began to re-examine the current situation and development direction of mine hoists in our country, and carried out some new structural tests and researches. On this basis, it learned from the new technology of foreign mine hoists, especially disc brake system technology. Designed my country's first large-scale single-rope mine hoist with a drum diameter of 6 m.

In addition, with the widespread use of shaft tower multi-rope hoists, their limitations have gradually emerged. For example, when the hoist is installed on a reinforced concrete shaft tower, its seismic resistance is far inferior to the steel structure derrick; when the mine passes through the quicksand layer and the geological conditions In poor areas, geological steel structure derricks with reinforced concrete shaft towers are used. In 1977, Luoyang Mining Machinery Factory developed my country's first floor-standing JKMD2×2 multi-rope friction hoist.

In the late 1980s, through the introduction of some new foreign technologies, Luoyang Mining Machinery Factory was able to produce a variety of new large-scale mine hoists, including large-scale multi-rope friction hoists with motor suspension and direct connection, with friction wheels up to 4 m in diameter. . In order to achieve standardization, generalization and serialization of hoist manufacturing, Luoyang Mining Machinery Factory has formulated national standards for single-rope winding and multi-rope friction hoists.

At the end of the 1990s, with the development of mines in our country towards large-scale and high-yield mines, multi-rope friction hoists became the dominant mining equipment, especially large-scale multi-rope friction hoists, which had significant advantages. Welcomed by mine users. At the same time, with the continuous progress of control technology, it is increasingly urgent to develop a new generation of large multi-rope friction hoist with advanced research technology, reliable performance, and high efficiency and energy saving. In 1999, CITIC Heavy Industry Machinery Co., Ltd. (hereinafter referred to as CITIC Heavy Industries) began to research and develop and in 2001 successfully manufactured the largest domestic double-motor direct-coupled JKMD-5.7×4 floor-standing multi-rope friction hoist. The friction wheel has a diameter of 5.7 m. It is the first domestic multi-rope friction hoist with a dual-motor suspension and direct connection, which has changed the situation that my country's super-large hoists rely on imports.

In the past ten years, with the comprehensive upgrade and transformation of CITIC Heavy Industries' technical equipment, the equipment specifications, performance and accuracy of the equipment have been comprehensively upgraded, and the manufacturing process of products has also been greatly improved, and further improvements have been made in product development methods and methods. With international standards. From 2008 to 2013, CITIC Heavy Industries supplied the domestic market with more than 200 hoists of various specifications and types each year, and exported them to Bangladesh, Iran, Venezuela, Turkey, Pakistan, and Zambia. In 2014, CITIC Heavy Industry exported a large floor-standing JKMD5.5×4PⅣ multi-rope friction hoist to Poland, with a friction wheel diameter of 5.5 m, which was driven by a dual-motor and a direct suspension connection.

In recent years, although the technical level of mine hoists in our country is getting smaller and smaller compared with developed countries, it still exists, especially in the performance and quality of certain products, as well as providing solutions for specific users to solve individual problems. Ability and so on. At present, my country still imports some mine hoists every year. Although the import quota is not large, the import quota of its electronic control system is relatively large.

At present, the representative maximum technical parameters of domestic hoists are listed in Table 1.

2　The development of foreign hoist

The development of foreign hoists has a history of more than 150 years. The representative periods are: in 1827, the first steam hoist appeared in Western countries; in 1877, the first single-rope friction hoist was manufactured; in 1905, due to the development of electric power, the first appeared Electric-driven mine hoists gradually replaced steam hoists; in 1938, the first multi-rope friction mine hoist came out; in 1957, the multi-rope winding hoist came out.

In order to adapt to the deep development of the mine (deep shaft) and the increasing demand for annual output, a multi-rope friction hoist was developed, that is, a few steel wire ropes with a smaller diameter are used instead of the original one with a thicker diameter. Promote.

From the application of the first multi-rope friction hoist in 1938, until 1948, there were only 6 hoists in operation in the world. By the end of 1959, there were more than 240 hoists. From 1938 to 1972, the Swedish ASEA company manufactured 224 friction hoists and supplied them to 23 countries, of which 4 rope hoists accounted for 57%; in 1968 they began to supply 6 rope hoists, accounting for 10%; in 1972 Supply of 8-rope and 10-rope hoists account for 5%. As of 1974, it is estimated that more than 600 multi-rope friction hoists are in operation worldwide.

Although the multi-rope friction hoist was originally used in deep well hoisting, it is currently used in shallow well hoisting in many countries. At present, multi-rope friction lifting has become one of the development directions of modernization, and it is developing in the direction of large-scale and fully automated.

According to statistics, the maximum technical parameters of representative multi-rope friction hoists used abroad are listed in Table 2.

3　 built-in hoist

The built-in hoist is a multi-rope friction hoist with a built-in electric motor. It is a new type of hoist with electromechanical integration, which is different from the conventional hoist. The connection method is not simply to install the motor in the friction wheel, but to integrate the mechanical and electrical parts. The friction wheel serves as the outer rotor of the motor and has the dual function of carrying the load of the wire rope. The motor stator and the friction wheel are coaxial Concentric arrangement, that is, the shaft of the friction wheel is the shaft of the motor stator at the same time, the rotor is outside, the stator is inside, the friction wheel and the motor are combined into one, and the motor is in the middle of the two main bearings, reducing the factors affecting the motor eccentricity and improving Safe and reliable operation.

In 1988, the world's first built-in hoist was officially put into operation in the New Ramberg mine in Germany. The mechanical part of the hoist is manufactured by GHH Company in Germany, and the electronic control part is manufactured by Siemens. Its friction wheel diameter is 6.5 m and the motor rated power is 2 200 kW. The hoist embodies a high degree of electromechanical integration and a high degree of electromechanical integration, which makes the transmission technology of the hoist enter a new stage, which has attracted the attention of domestic and foreign counterparts.

The built-in hoist has the following advantages:

(1) The structure is compact, the motor does not need to be installed, which reduces the area of the machine room, especially for the tower hoist, which can reduce the cost of the well tower;

(2) The torque of the motor is directly transmitted to the cylinder shell of the friction wheel, the transmission chain is short, and the transmission efficiency is high;

(3) The force on both ends of the spindle device is symmetrical, so that the force on the spindle and the bearing is uniform, and the rigidity of the spindle is improved;

(4) There is no need to adopt the motor rotor suspension structure, which reduces the deflection of the main shaft, reduces the deviation of the air gap between the motor rotor and the stator, and makes the operation more stable;

(5) The temperature rise of the motor will not cause asymmetry and will not affect the air gap of the motor;

(6) Mechanical and electrical integration, the maintenance of the hoist is small, and the operating cost is low.

The disadvantage of the built-in hoist is that the equipment is expensive. In 2005, the two sets of shaft tower 4.65×6 built-in hoists introduced by Xinji Liuzhuang Mine cost more than 200 million yuan.

The built-in hoists used in our country are all imported from abroad. For example, the auxiliary shaft of Donghuantuo Mine introduced 1 floor-standing 4.3 m hoist in 1994; Dayan Coal Industry Company No. 3 mine main shaft introduced 1 shaft tower of 4 m in 1995 Hoist: The main shaft of Chensilou Mine in Yongxia Mining Area introduced a floor-standing 4 m hoist in 1996, all manufactured by German Simag.

Although the manufacturing field of built-in hoists in my country is still blank, the built-in hoists are only a new form of hoist development, which is a perfect combination of mechanical and electrical. It will coexist with direct-connected hoists. , And will not replace the direct-coupled hoist. In the selection of the connection method of the hoist, it is usually necessary to take into account many factors such as the price of the equipment and the operational reliability, and comprehensive consideration should be given to choosing a reasonable price-performance ratio.

The development prospect of 4　km deep well

The current coal mining depth in my country is generally less than 800 m, and a large amount of coal has not been developed due to the depth of more than 1,000 m underground. With the rapid economic development, the society's demand for energy is increasing. Deep coal mining has become a problem that the world's major coal mining countries need to face and solve. According to statistics, the current average coal mining depth in my country is about 500 m, and it is developing into the deep at a rate of 8-12 m per year. In the next 10 years, the mining depth of our country's mines will surely reach 1 000 ~ 2 000 m.

In the early 1980s, the mining depth of German coal mines had reached 1 443 m. By the mid-1980s, there were at least 79 foreign mines with a depth of more than one kilometer. In 1977, my country’s Zhaogezhuang Coal Mine was exploited to a depth of 1154.4 m. At present, there are at least 17 mines in my country with a mining depth of more than one thousand meters.

When the multi-rope friction hoist is used in a deep shaft, the hoist wire rope is lengthened, which not only increases the lifting load, but also because of the excessive tension change of the wire rope under deep shaft hoisting conditions, its life will drop sharply, which restricts the safety of mine hoisting The main factor with efficiency. The common problems of deep-well hoisting wire ropes are: early and uneven wire breakage, reduction of the effective metal cross-section of the wire rope, lower tensile strength, lower overall breaking force, etc., resulting in a shorter service life of the wire rope. For example, the lifting height of Tongling Dongguashan Copper Mine is 1 100 m, and the average service life of the wire rope is about 3 months; the lifting height of the main shaft hoist of Zhang Xiaolou, Pangzhuang, Xuzhou is 1 039.6 m, and the average service life of the wire rope is 6 months; therefore; , The domestic multi-rope friction hoist is not recommended to be used when the depth exceeds 1 200 m.

Under normal circumstances, for deep well lifting, the segmented lifting method can be used, that is, the mature single-rope winding hoist or multi-rope friction hoist is used for segmented mining. The technology is easy to achieve, but more equipment is required , Production and management costs will increase significantly, and increase the probability of failure; another way is to use Blair hoist (ie multi-rope winding hoist), only one set of hoisting equipment can be completed, avoiding The complicated operation system and chamber engineering brought about by multi-stage lifting saves the investment cost.

In 1958, South Africa began to use multi-rope winding hoists, and they are widely used in mines with a hoisting height of about 2 000 m. The multi-rope winding hoist is a double-drum winding hoist. There is a rope baffle in the middle of each drum, so that 2 steel wire ropes can be wound on each drum at the same time. Two steel ropes behind the wheel device are connected to the same lifting container. Because it is no tail rope hoisting, it avoids the influence of excessive changes in the tension of the hoisting wire rope due to the change of the tail rope in the deep well hoisting on its service life.

The multi-rope winding hoist has many advantages such as large lifting capacity, small drum diameter, multi-level hoisting when using double hooks, no tail rope device, and suitable for extra-deep well hoisting. It solves the multi-rope friction hoist. The wire rope problem in deep well hoisting has changed the hoisting mode of deep well mining. This upgrading technology has been applied to a certain extent in foreign countries, but the application in China is still blank.

Deep coal resources are an important part of my country's energy security. In the future, many mines will gradually enter deep mining; therefore, deep mining will become the future development trend of the mining industry. Deep lifting is an important problem to be solved in deep mining. Due to the high stress and high temperature of the special geological environment of the kilometer deep well, new requirements are put forward for the lifting of transportation equipment, and it also poses new challenges for the technicians. How to mine and transport deep coal resources safely, efficiently, and at low cost will become a major technical issue that my country's coal industry needs to break through.

5　The status quo of domestic hoist industry

Throughout the history of the development of hoists in my country, from single-rope winding to multi-rope friction, from reducer transmission to electric motor and main shaft direct drive, the development and manufacturing of hoists have made great progress.

In the past 10 years, domestic hoists have always occupied an absolute advantage in the domestic market. This is related to price factors and national policies, but it also objectively reflects the high dependence of the domestic market on domestic equipment. Although the imported equipment is of good quality, the price is high, and users pay more attention to the cost-effectiveness of the product. In recent years, the improvement of the performance and quality of domestic hoist has promoted its market share.

At present, domestic companies producing mine hoists include CITIC Heavy Industries, Shanghai Metallurgical Mining Machinery Factory, Shanxi Xinfusheng Machinery Manufacturing Company, Sichuan Mining Machinery Group Co., Ltd., Jinzhou Mining Machinery Group Co., Ltd. and Chongqing Taifeng Mining Machinery Co., Ltd.

With the rapid growth of coal production, the demand for mine hoists has also continued to increase. ABB and Siemag have established hoist manufacturing bases in China to expand the domestic market by reducing manufacturing costs and intensify the domestic hoist manufacturing industry. Competitiveness. The products of multinational companies represent the technological manufacturing level of modern upgrading equipment in terms of reliability, intelligence, and automatic control. It also stimulates the domestic market to upgrade the machine manufacturing industry, changing design concepts, optimizing design methods, developing ideas, and constantly innovating to adapt Market requirements.

It is worth noting that due to many factors such as my country's weak industrial foundation, lack of technological innovation capabilities and backward product technical standards, the overall strength of my country's mining machinery manufacturing industry is weak and lacks international competitiveness. A considerable number of mining machinery manufacturing enterprises can only engage in the imitation of some simple products with low technical level, and are unable to engage in new product development. They can only participate in market competition at low prices.