Research on emergency hoisting method of mine hoist

2025-03-10 15:03:54

In view of the special circumstances such as power failure or motor failure in the whole mine, 

emergency lifting methods such as non-powered gravity decentralization and external power-assisted lifting are proposed, 

the composition, working principle and applicable occasions of the equipment are introduced,

 and the necessary functions such as auxiliary lifting hydraulic system, 

auxiliary lifting electrical control system and emergency power supply involved in external power-assisted lifting are elaborated in detail, 

as well as the precautions in the use of emergency lifting.

Mine hoisting system is used for the transportation of personnel, materials and shafts Ore is the throat equipment of underground mining mines.

 In the event of an anomaly at the underground working face, 

the mine must respond to emergencies and use elevators to ensure the safety of people underground. 

Once the elevator cannot operate normally, it will seriously affect the normal production and personnel safety of the mine.

 Mining enterprises must put safety production in the first place, 

and solving the emergency operation problem of mine hoisting system has always been an important problem faced by mining enterprises.

From the control system, transmission system to braking system, there are many ways to improve the reliability of the equipment itself, 

such as the failure driving mode when the control system is designed with a local failure; 

The transmission system is designed to set up DC or frequency conversion devices, and a single set of faults is switched to full-load half-speed mode; 

The safety braking circuit of the hydraulic braking system is multi-way constant deceleration redundancy, etc. 

In special situations such as mine-wide power outages or motor failures, the authors further discuss the emergency lifting methods that can be used in the mine,

 when the original lifting system cannot be restored in a short time.

1 Non-powered gravity devolution

1.1 Principle

Taking advantage of the tension difference between the two sides of the container, by adjusting the opening pressure of the brake,

 the lifting container on the heavier side is slowly lowered, and the lifting container on the lighter side is slowly raised, 

and it stops smoothly after reaching the predetermined position. When the whole mine power failure, motor damage and other faults occur, 

the short-term lifting system can not resume normal operation, and when the personnel are trapped in the tank cage, 

the gravity decentralization device can move the tank cage to the adjacent working face in time to realize the personnel get out of the predicament.

1.2 Equipment Required

Gravity decentralization requires hydraulics, operating control elements, and emergency power supplies. 

ABB generally integrates the gravity decentralization function in the gate control system, 

and uses the hydraulic station and control cabinet of the gate control system to realize the gravity decentralization function. In addition, 

CITIC Heavy Industries also has an independent gravity decentralization device, which is more suitable for on-site retrofits, 

including a separate hydraulic station, a small operator station and a battery cabinet. 

The hydraulic station and the original system hydraulic station are manually switched through the switch on the pipeline;

 The console is equipped with a speed-hydraulic dual closed-loop controller, and the encoder is used as a speed monitoring element; 

The battery cabinet supplies power to the console and hydraulic station and can be used in the event of a mine-wide power outage. 

During gravity decentralization, the system can always monitor the speed and gate temperature, and has safety protection such as overspeed,

 high brake oil pressure, power failure, gate temperature overrun, etc. With safety in mind, 

the system can also accurately calculate the container position for precise stopping of the tank cage and overroll protection.

1.3 Applicable working conditions

The non-powered gravity decentralization method has low investment cost and can solve the

 rescue problem of trapped tank cage personnel under special working conditions. However, 

this method is only suitable for short-term low-speed single operation, and cannot solve the problems of long-term power outage, 

groundwater level rise, and safe well ascent of all employees. Gravity decentralization is not applicable to all mines and working conditions. 

For example, when the vessels and loads on both sides of the system are similar and the tension is balanced, it is possible that it will not be operational.

2. Assist in the emergency response of external power

External power emergency assisted lifting is an emergency rescue method that uses newly invested external power to continuously and

 safely lift personnel under extreme circumstances such as motors and electrical transmission devices.

 The auxiliary lifting equipment is usually composed of a mechanical transmission system, an auxiliary lifting hydraulic system, 

an auxiliary lifting electrical control system and an emergency power supply.

 According to the different load and speed requirements in the emergency rescue process, the design should adopt the corresponding structure type.

2.1 Mechanical drive system

2.1.1 Ring gear drive type

The main engine specification of the hoist in use in a coal mine is JKMD-4×4ZIII., and the emergency improvement requirements are: 

40 people in the tank cage, the running speed is 1.2 m/s, and the motor power is calculated to be 90 kW. 

The motor has small power and limited space on site, and is designed with ring gear transmission mechanical structure, 

which includes ring gear, pinion, reducer, motor and base.

2.1.2 Coupling type

In order to meet the requirements of emergency lifting load of several tons to more than ten tons and high emergency lifting speed, 

quick connection couplings can be used to assist in lifting mechanical structure, including couplings, gearboxes, motors, etc.

2.2 Auxiliary lifting hydraulic system

Emergency lifting is usually not fast. The traditional secondary braking hydraulic station can be used to assist the lifting hydraulic system, 

which can work continuously for a long time. In order to ensure reliability,

 the hydraulic station should be equipped with two sets of oil pump devices and electro-hydraulic ratio pressure regulating devices,

 one for work and one for standby. The hydraulic station should be equipped with sensors such as pressure, temperature, liquid level, etc., 

and redundant return pipelines should be connected in parallel to meet the requirements of safety procedures.

2.3 Assist in improving the electronic control system

In order to meet the reliability of continuous safe work over a period of time, the design of 

the auxiliary improvement electrical control system should meet the requirements of safety procedures. 

The main control adopts the main control, starting from two sets of PLC systems equipped with redundant position, 

speed and other monitoring sensors; Manual/semi-automatic/slow-motion operation modes can be selected; 

It has the functions of digital travel monitoring, system operation data display and fault alarm. In addition, it should have the following features:

(1) Power switch monitoring function of power supply circuit;

(2) Control and monitor auxiliary equipment such as hydraulic systems and cooling fans;

(3) Cooperate with the inverter to realize the adjustment and control function of speed and torque;

(4) Switching condition monitoring function in the wellbore;

(5) Coil diameter calculation function to correct the elevator depth calculation coefficient;

(6) The hoist control system and the hoist signal are locked with each other;

(7) Monitoring and failure of the self-diagnosis system.

2.4 Emergency Power Supply

Most mining enterprises are equipped with diesel generators as an emergency power source, 

but the mine elevator is a four-quadrant operating equipment with a heavy object decentralization power generation operation state. 

If the diesel generator supplies power to elevators and other equipment of similar power at the same time, 

the electrical energy generated during power generation can be consumed by other equipment in the grid, and the grid can remain stable; 

If the diesel generator is mainly used to supply power to the lifting system,

 the auxiliary lifting inverter should be designed as a power consumption braking type, 

and the energy during power generation is consumed by the braking unit on the resistor, 

so as to maintain the stability of the power supply voltage of the diesel generator and avoid overvoltage shutdown.

3 Conclusion

The investment of non-powered gravity decentralization equipment is low, 

and it can only be used for emergency rescue of personnel in the tank, and its applicability is narrow. 

The external power emergency auxiliary lifting mechanism can integrate the gravity decentralization function into its own system, 

which can not only rescue the personnel in the tank when it is fully loaded, but also realize the continuous lifting of light loads,

 and have a wider range of applications. Among them, the coupling emergency auxiliary lifting mechanism covers a large area and has a high investment, 

which is suitable for new mines; The gear transmission emergency auxiliary lifting mechanism occupies a small area and has little investment. 

It is more suitable for the transformation of existing lifting equipment, with higher applicability and wider application prospects