Equipment and suppliers news (December 01, 2002)
Full-synthetic transmission/ hydraulic fluid for wear protection
Petro-Canada has launched Duratran Synthetic, the first full-synthetic transmission/hydraulic fluid (THF) for use in off-highway machinery. The lubricant features Petro-Canada’s unique Total Temperature Protection formula. In comparison tests, Duratran Synthetic performed better than the leading OEM THF, retaining fresh oil properties longer and protecting new equipment better against wear. In hot and cold temperature extremes, Duratran Synthetic proved to protect gears and bearings better, even in the presence of water.
Petro-Canada has also introduced its new Duratran No-Nonsense Warranty. This guarantees the repair or replacement of damaged equipment parts resulting from a failure due to defects of Petro-Canada’s Duratran THF, if it has been used in accordance with the equipment manufacturer’s and Petro-Canada’s recommendations, whether or not the equipment is still under OEM warranty.
Duratran can be purchased in Canada through Petro-Canada Associates by calling 1-800-268-5850. Technical and after-sales service support is available, including used oil analysis and disposal, bulk storage and dispensing, and product training. For more information visit www.petro-canada.ca.
Release of scalable business solution
Gemcom Software International Inc. of Vancouver, B.C., has released GEMS 5.0, a robust system that includes a broad range of technical applications to manage all aspects of mine-site performance. GEMS 5.0 is designed to address the needs of all mining operations. Its powerful, flexible architecture offers the ability to adapt to operations of all sizes and output levels. This release represents the outcome of several years of research and development, backed by feedback from diverse clients who have implemented pilot and subsequent commercial versions of GEMS at their mine sites.
The key new feature of GEMS 5.0 is its inherent scalability, which will allow Gemcom to roll the system out to all of its single desktop users. What may have once been alluring only to large-scale operations now addresses the needs of all sizes of mining operations. New features include enhanced block modeling capabilities, allowing users to execute multiple block model projects of varying size and orientation in a single session. Other specific features include new ore accounting tools, which allow for greater log report detail, and enhanced data storage, which boosts the security of user databases.
For more information, visit www.gemcomsoftware.com.
Technical tips for fan maintenance
by Neil Fraser, P.Eng.
senior engineer,
CH Ljungberg Inc.
Cambridge, Ont.
A common problem that has to be battled in fan maintenance is rapid thermal expansion or a “rapid Delta T” condition. It is not uncommon for a process piece of equipment to see temperature extremes such as 800*F, or higher, as well as starting at -40*F temperatures.
Equipment materials need to be selected to handle the temperature extremes. The lubricant and lubricant system must ensure the right viscosity at the cold end so that the bearings will operate properly while protecting the bearings and lubricant from overheating at the high end. In addition if the fan experiences the two temperature extremes within a very short period of time, then issues related to different rates of component expansion also have to be addressed.
Even though two components are made from the same material, a thin component exposed to a source of heat will see a more rapid increase in temperature than a thick component. A backplate, for instance, is generally made of steel plate whereas the hub is often made of a massive piece of cast iron or steel forgings. Under rapid delta T conditions the thinner backplate will act as a conducting fin and grow quicker than the hub. When this uneven expansion takes place the stress is transmitted through the bolts or rivets and can actually shear through the backplate.
Similarly a cast iron hub often has a large diameter end. This large surface area can result in a more rapid change in temperature than the shaft, which is essentially a compact block of steel. In this case the bore of the hub can expand quicker than the shaft, and the fit between the hub and shaft may be lost. Eventually the thicker component will “catch up”, but damage can occur while the temperatures are stabilizing. Shaft looseness or movement of a bolted hub/backplate connection can result in a change in the wheel’s centre of rotation. The resulting imbalance can cause damage to the bearings through increased vibration levels.
Rapid delta T events can be accommodated with good design. To combat hub/shaft movement, interference fits are used. To eliminate movement at the hub/backplate bolted connection, fitted bolts are often used. There are many other ways to accommodate differing expansion rates in order to prevent either harmful stresses or mechanical looseness from developing. Suppliers have various preferences, so it is worthwhile to discuss the options with a few.
In conclusion not only is it important to spell out what the equipment will experience, but in some cases, when it will experience it can be just as an important.
Neil Fraser specializes in equipment selection and application for heavy industrial markets including the mining industry, and can be reached at neil.fraser@rogers.com.
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