Performance and Safety Considerations of Hydraulic …
The manufacturer of the oil can provide accurate data on the bulk modulus. A value of 320,000 psi is recommended in the absence of manufacturer data. This value can also be used for water-oil emulsions such as those used in longwall shields. K„ = stiffness of stage n, lbs/in. = area of stage n, in2.
Mechanical analysis of the structure of longwall mining hydraulic
A column hydraulic cylinder, balance hydraulic cylinder, rear connecting rod, and shield beam were treated as simplexes in the model to simulate the bearing capacity of the structure. Xu et al. 5,6 investigated the bearing capacity of a two-column shield hydraulic support using a plane bar support system model. After analyzing the …
Customized Roof Support Systems
The Longwall Top Coal Caving (LTCC) roof support allows mining to a total seam height of more than 10 m (33 ft) by using a longwall shearer to cut the bottom 2.8-3.0 m (9.2-9.8 ft) and then caving the top coal behind the roof supports onto a rear AFC. This type of longwall is in service for example at a mine in the Hunter Valley, Australia.
Hydraulic Controls – Australia's Most Trusted Fluid Power …
Hydraulic Controls is committed to providing exceptional service in the design, manufacture and supply of fluid power systems. Our objectives include creating satisfied stakeholders and continually improving our management system. To that end, we have developed a custom framework to establish, maintain and achieve these objectives.
Longwall Pump Stations | LW Hydraulics | Australia
Longwall Pump Stations. Hydraulics pump stations are customised to the requirements of each customer. They are an integrated design incorporating modern materials, equipment and technology. Pump Stations can be based on a tracked mobile platform, transportable pods or even suspended from the monorail system; they typically incorporate the ...
Guideline for fluid power safety systems at mines
5.1. General. This section applies to the commissioning of the fluid systems at mines, including pumps, hoses, valves, gauges, accumulators, filters and actuators. Fluid power systems should be commissioned in accordance with the designer's documentation and ISO 4413, ISO 4414 and AS 4041 as applicable.
THE NIOSH SHIELD HYDRAULICS INSPECTION …
ABSTRACT. Longwall shields provide essential ground control in longwall mining, yet a high percentage of shields are operating at less than peak capacity and many at well …
Improving safety and productivity in coal mines
Around 90 per cent of Australia's underground coal production comes from longwall mining. Traditionally, a mechanical shearer cuts along the coal seam beneath a roof supported by hydraulic jacks, exposing miners to multiple risks. Increasing safety and productivity in longwall mining has been a long-term industry goal.
The simulation of fluid flow in safety elements of longwall …
The paper presents the research on pressure variation in elements securing the shield support against overloading. The chosen constructions of connecting pipe were analysed and its flow characteristic were determined. The operational parameters of different connections were also considered in light of their interaction with whole …
Design Considerations for the Next Generation of …
capacities, while the hydraulic setting pressures have remained constant in the 4,000 to 4,200 psi range. This design practice coupled with the increased stiffness of the higher capacity supports means that the higher capacity shields are fully loaded as often as their lower capacity predecessors (figure 3). Hydraulic Components and Control Systems
Hydraulic Control Systems for Longwall Shield Supports
Abstract. Recent shield support developments demand a new approach to hydraulic control systems due to higher support loads, heavier supports and greater speed of operation demanded to cater for modern coal machines. The paper reviews system requirements and systems currently developed i.e.:-. Adjacent support control.
8.4.2c Longwall Mining | GEOG 000
Longwall Mining of Coal. Longwall mining of coal is a high production and high productivity method, employing sophisticated electrical, mechanical, and hydraulic systems, as well as computer-based monitoring and control systems. Most modern (coal) longwall faces are semi-automated. It is noteworthy that longwall operations in trona …
Measurement and analysis of the roof pressure on hydraulic …
The mining method employed is the longwall coal face, in which caving is controlled by means of individual hydraulic props.We first report the empirical formulas used to estimate the roof pressure ...
Details Home
Longwall mining is an underground mining operation in which a large panel or block of coal spanning up to 1,500 feet across distances of two to three miles is extracted. Longwall mines are characterized by low ceilings and tight spaces in which workers must operate heavy duty machinery. Hydraulic-powered roof supports, also called shields ...
Reducing risk of hose assembly failures
"The objective of this project is to identify possible improvements in longwall hydraulic system and hose assembly selection, management, operation and maintenance to reduce the risk of injuries and to maximise effective hose assembly service life." ... 41 for fluid power safety systems in mines. The guideline pushes mines into setting up ...
High-pressure incident prompts safety alert
17 February 2010. The perils of high-pressure hydraulic power are well known in the industry, with up to 20 longwall miners injured every year. A high-force jet of hydraulic …
Safety alert: longwall hydraulic system over …
A longwall hydraulic system became over-pressurised, resulting in the catastrophic failure of hydraulic isolation valves and other fittings in the pump station. These failures …
Performance and Safety Considerations of …
Hydraulic cylinders are used in several roof support systems, such as longwall shields and mobile roof supports, to provide critical ground control. Many state-of-the-art hydraulic …
Development of a Hydraulic System for the Automatic …
A mechanical support in a longwall complex requires proper supervision and control of operating parameters because it is responsible for the safety of machines and workers. Its main functions are to protect the excavation against the adverse effects of rock mass and to move it along with the operational progress of the shearer and the scraper …
Development of a Hydraulic System for the …
The pressure drop in the hydraulic system after expanding the sections in the longwall excavation causes uneven support of the roof along the length of the wall. This affects the improper cooperation of the …
Automation in U.S. longwall coal mining: A state-of-the-art …
The power train, which consists of power centers, hydraulic supply pump system, rock duster, water pumps, tool and supply cars, etc., is normally on a track or skids in the second entry outby the face and can easily be moved with the moving longwall face. ... Improvements in health and safety of semi-automated longwall system since mid …
Nonimpact rock pressure regulation with energy …
PDF | On Dec 31, 2021, V. V. Gabov and others published Nonimpact rock pressure regulation with energy recovery into the hydraulic system of the longwall powered support | Find, read and cite all ...
Dynamics of Hydraulic Leg of Powered Longwall Support
K. Stoinski, "Joint operation of valve block with hydraulic leg of powered longwall support," in: Proceedings of Scientific and Technical Conference on Testing, Designing, Manufacturing, and Maintenance of Hydraulic Systems [in Polish], Gliwice, Szczyrk (2000). "Polish Standard PN-G-50041:1994. Labor protection.
Fluid Power Systems for Longwalls
The hydraulic networks that deliver emulsion from the tanks in the headgate to the last shield on the face also determine the overall efficiency of operations. by alcwyn elliott. With today's modern longwall mining systems, fluid distribution from the high-pressure pumps to the last shield on the face has to be efficient in all respects ...
Longwall mining demands safety and reliability in equipment
This system uses a range of data supplied from equipment used in the process of continuous longwall mining and uses it to calculate the changes in demand for hydraulic fluid before they occur.
Hauhinco Water Hydraulics
Hauhinco high-pressure stations for longwall hydraulics are premium, certified systems with all the necessary approvals. This also applies to the spraying stations for the supply of the shearer water sprays, coal plow operations and cooling systems of drive motors. Hauhinco systems guarantee the necessary safety and …
Roof Support Systems
support control systems ranging from manual hydraulic controls to the highly acclaimed PMC™-R electronic control system for the most advanced face automation and equipment monitoring. Top priority is given to control flexibility, user friendliness, reliability, ease of maintenance and safety. The PMC™-R electrohydraulic longwall
Analysis of support by hydraulic props in a longwall working
Performance and safety considerations of hydraulic roof support systems. Proceedings of 17th International Conference on Ground Control in Mining, Morgantown, WV, pp. 176-186. Manual of FLAC ...
Hose Safety and Reliability in Mining | Power & Motion
The movable hydraulic shields in longwall mines advance with the shearer throughout the mining process, enabling increased productivity as well as improved …
