printer friendly version
Seismic event simulator
4th Quarter 2011, Hydraulic systems & components
Seismic events can lead to rockbursts in mines and can result in injury or death to mining personnel. The Dynamic Prop Tester was designed to test hydraulic props, which are used in mines to mitigate the effects of rock bursts by absorbing energy and hence reducing rockburst damage. A prop consists of two telescoping steel cylinders which are extended by hydraulic pressure, which in turn is generated by a hydraulic pump powered by air.
The test machine was built and commissioned by Gauteng Metrology Services, a company that manufactures special testing machines and refurbishes and upgrades all makes of test equipment. The client was Elbroc Mining, a manufacturer of non-sacrificial and sacrificial mine props.
Rapid yielding hydraulic props were introduced into the South African mining industry in 1970. These props rapidly gained popularity on mines which were experiencing rockbursts. Expansion and deepening of mining activities, combined with the need to meet operational and safety requirements, has resulted in increased demand for these props.
Developed by Elbroc, these sophisticated patented hydraulic props are now used in many South African gold mines. They meet CSIR and Chamber of Mine Research Organisation (COMRO) guidelines for the safety of hydraulic stope support and are designed to slow yield at 20 tons and rapid yield at 40 tons, with a travel capacity of 300 mm to 500 mm, which enables them to withstand seismic events. They are used in stopes up to four kilometres underground, where conditions include a typical roof movement of up to 35 mm in 24 hours. This requires a high level of engineering and component quality. Following manufacture, performance characteristics are verified through batch testing, where they are exposed to both slow yield and rapid yield of up to 3 ms-1.
CSIR and Comro specifications
The Dynamic Prop Tester was first required to compress the prop at 30 mm/min for a displacement of 100 mm. Once the prop reached a static load of 200 kN (20 ton) and had completed the displacement required, the dynamic test phase was triggered. This phase compressed the prop at a rate of 3 m/s for a displacement of between 100 and 200 mm. This released the relief valve on the prop, which had to attain a peak force of 500 kN (50 ton). Once this was completed, the machine had to go back to static testing (100 mm displacement at 30 mm/min).
A machine to meet the challenge
To meet these stringent demands the test machine had to have a variable static speed of 0–120 mm/min and a dynamic capability of 3 m/s. The data acquisition system was capable of a sample rate of 49 kHz. The machine frame capacity was rated for 100 ton maximum for safety reasons.
Specially developed software
Gauteng Metrology Services developed the interface electronics and software in-house to process the data, generate real-time graphs and print out a report on the performance of each prop against the required test specifications.
For more information contact Sidney Badenhorst, Hydromobile, +27 (0)11 394 5837, firstname.lastname@example.org, www.hydromobile.co.za
- Effect of brake heating on component durability
1st Quarter 2015, Hydraulic systems & components
The Mechanical Engineering Department at the University of the Witwatersrand is conducting research on the effect of heat from truck brakes on the temperature of surrounding vehicle components, assisted by donations from BPW, Siemens, CT Hydraulics, Fluid Power Group and Hytrain.
- New improved hydraulic motors
1st Quarter 2015, Hydromobile S.A. , Hydraulic systems & components
Hydromobile’s new range of 2-bolt 25 mm shaft hydraulic motors now includes an additional shaft bearing to absorb additional side load and prolong its overall lifecycle. Units are already available off ...
- Hydromobile training: 2015
1st Quarter 2015, Hydromobile S.A. , News & events
Hydromobile’s popular hydraulics training course will be run on the following dates in 2015: 25-27 March, 24-26 June, 11-13 November.
It gives students a good general understanding of hydraulic system ...
- Hytec and Power Team get torqueing
1st Quarter 2015, Power Team SA, Hydraulic systems & components
When industrial projects company, Bühler, needed a series of bolts to be torqued to precise levels within a strict deadline, they contracted Hytec in Durban to manage the process. This safety-critical ...
- Energy efficient hydraulic systems
1st Quarter 2015, Voith Turbo, Hydraulic systems & components
With Voith’s innovative new hydraulic systems, operators of sheet metal processing systems will be able to save up to 80% energy while simultaneously increasing productivity.
- Sun filter cartridges protect hydraulic systems
1st Quarter 2015, Axiom Hydraulics, Hydraulic systems & components
Hydraulic systems contain multiple parts and vary in complexity, but for longevity and reliability, they all need protection from oil-borne contamination. If abrasive particles enter an hydraulic system, ...
- High-performance hydraulic hose solution
1st Quarter 2015, Parker Hannifin (Africa), Hydraulic systems & components
Parker Hannifin has introduced theGlobalCore range – five hydraulic hoses and two fittings series that significantly reduce engineering and service complexity by providing the first comprehensive product ...
- Advanced Fluid and Transmissions services
1st Quarter 2015, Hydraulic systems & components
Advanced Fluid and Transmissions is one of the few one-stop service companies that offers design, manufacturing, supply on demand and repair services for a comprehensive range of hydraulic, pneumatic and power transmission systems to both private and public sectors.
- New hand pump range
1st Quarter 2015, Blanes Instruments, Hydraulic systems & components
The new Holmatro hand pumps offer significant advantages relating to reliability, maintenance, durability, price and quality.
- The full hydraulic flow solution
4th Quarter 2014, Hydromobile S.A. , Hydraulic systems & components
Hydromobile has added the Lake Monitors series of products under its vast umbrella of hydraulic components and equipment, resulting in an even more comprehensive offering to its customers.
- Hyflo leads the way in piping installations
4th Quarter 2014, Hyflo Southern Africa, Hydraulic systems & components
GS-Hydro is a world leader in non-welded piping technologies and is a global supplier of complete, non-welded piping solutions.
- World-first for local hydraulics company
4th Quarter 2014, Hydraulic systems & components
The Powerstart pre-engaged hydraulic starter is the first third-party Atex certified starter motor compliant with EN13463-5, EN13463-1, EN13463-8, EN1834-1 and EN1834-2 norms.