support centres the Devico survey instruments are also constantly gaining recognition worldwide. The DeviFlex non-magnetic survey tool has achieved wide acceptance as an affordable and accurate alternative to the gyro technology, and is now the most popular Devico survey instrument on the market.”
With the growing popularity of the survey instruments the production and quality control has been modernised and made more effective. New calibration rigs have been constructed to reduce calibration time and to improve the specification and overall performance of the instruments. Additionally, Devico has created two test holes at its head office in Norway, so the in-field accuracy of each instrument can be confirmed.
The test holes consist of a 250 m long horizontal borehole to test non-magnetic instruments, and a 150 m long hole for magnetic instruments. Since the holes are horizontal and located close to the surface a reference survey was performed with high accuracy GPS. The complete borehole lengths were surveyed and the exact positions are known within an error margin of less than 50 mm. The borehole trajectories include both straight and curved sections, with a maximum dogleg of 10° deviation over 30 m.
Both holes consist of two sets of pipes where
34 International Mining NOVEMBER 2009
a winch pulls a wire through in a loop. Instruments of all lengths and dimensions up to NQ size can be attached to the wire and pulled back and forth throughout the length of the hole. An accurate depth encoder delivered by Downhole Surveys in Australia has been installed, allowing surveys to be performed at any given depth interval.
As there are few test locations for survey instruments in Scandinavia, Devico has chosen to open this facility to any company that may wish to test the calibration and accuracy of their own instruments, independent of instrument type and brand.
Mining machinery has to operate in extremely challenging enviroment with high temperature, humidity and vibration. When it comes to heat exchangers, the information from the field is that there have been many difficulties with existing technology, such as aluminium products, Finnradiator reports. Aluminium is an economic solution for light-duty applications such as light trucks. In heavy-duty applications, such as machines for mining, the operational and environmental requirements favour the use of metals such as copper and brass. Their metallurgical excellence, for example tensile strength (copper 330 Mpa, aluminium 40 Mpa at room temperature) and thermal conductivity (copper 377 W/moC, aluminium 222 W/moC),
enables the optimisation of product reliability, which decreases life cycle costs and improves profitability.
CuproBraze is a new technology for manufacturing copper/brass heat exchangers that fulfills all current and near-future requirements of heavy-duty heat exchangers that is now hitting the market. The technology is implementated by Luvata Sweden (former Outokumpu) and is backed-up by the copper industry through the International Copper Association and by a recently established global interest group called CuproBraze Alliance.
The first generation of radiators was soldered copper/brass radiators. The second generation’s radiators are brazed aluminium radiators, which