Heat-intensive processes can put immense strain on equipment, which is why using the correct lubrication is essential to prevent component failure. Selecting the right product can be daunting, but Colin Ford, Managing Director at Lubrication Engineers (LE) South Africa says there are some helpful guidelines that maintenance teams can use when selecting the correct lubrication for their equipment.
One of the most important is the recommended maximum useful lifetime for a grease in high temperature bearings. “This can depend on many factors, from temperature to the size and speed of bearing, the amount of oxygen available to the grease in the bearing, the load on the bearing and the degree of external contamination,” says Ford. A reputable product should come with a guideline range for its use.
For example, field testing has shown that the maximum useful lifetime guidelines for the Almasol High Temperature Lubricant (1250) that LE supplies are 10 000 hours at 93°C, 100 hours 149°C and between one and four hours at 204°C.
“Lubrication interval recommendations for LE’s 1250 Almasol High Temperature Lubricant are much lower than the maximum useful lifetimes,” Ford says. “This is because normal bearing relubrication practices replenish only a relatively small portion of the grease and the bulk of the grease in the bearing, at any given time period, has been there for a much longer time than the lubrication interval.”
In addition, it’s important to consider the thickener of a grease. Bearings operating in or near heat-generating equipment are exposed to temperatures that cause general greases to melt and run, leaving critical bearing surfaces unprotected, so having an effective thickener can protect equipment.
LE developed the 1250 Almasol High Temperature Lubricant with a clay thickener system that has “one of the highest temperature capabilities of any grease thickener technology currently available in the industry,” adds Ford. It uses a base oil with a heavy viscosity and high flashpoint, and it has a high natural viscosity index. “The high temperature thickener has a high dropping point, making it a good choice for heat-intensive applications,” says Ford.
Assessing the application
Assessing the temperature needs of a particular application is also helpful when selecting a lubrication solution. The Almasol in LE’s 1250 Almasol High Temperature Lubricant is a solid wear-reducing additive in the product that is able to withstand extremely heavy loads, chemical attack and temperatures of up to 1,038°C. This makes the lubricant ideal for applications such as asphalt plants, brick/ceramic kilns, exhaust fans, kiln car bearings, lime kilns, oven conveyors, pellet mills, plastics and soot blowers.
Lubrication products used in these applications are subjected to much harsher conditions or higher temperatures than others. By choosing products specifically designed for challenging circumstances, you can protect your equipment, improve performance, and save on maintenance and repair costs.