« New : Level Measurement Blog | Main | When is fail-safe really safe? »

Hammermills, whether reversible or non-reversible, must be checked for several reasons. For example, if the coal grind goes out of spec, then vary the cage adjustment. Our hammermill cages allow adjustments to compensate for normal wear by changing the distance between the cage bars and the hammers. If that fails to correct the problem, then open up the hammermill and check the hammers and cage parts for wear.

Plugging: this sticky problem won't go away on its own

Extremely sticky feed materials can result in plugging, and if that occurs, a temporary solution is to adjust the cages back and/or cut back the feed rate. Continued running often clears the problem if the sticky material was transient in nature: if not, a washdown may be necessary.

When a bearing's hot, you're not

As with other crusher models, hammermills may also exhibit uneven wear as well as hot-running bearings. The most common solution is to adjust the feed system to correct the wear problem, and to check the bearings as described above. Both of those remedies are far less time consuming and expensive than the fixes that will otherwise be needed if they are neglected.

Reversible Hammermill Examples

Pennsylvania Reversible Hammermill, Model SXCB. This model is widely used to crush Powder River Basin (PRB) coal from Wyoming as well as bituminous coals. Because PRB coal has such a low sulfur content, power generating plants tend to prefer it over coals that might be nearer to their generating station but which would require more expensive emissions control systems.

Since the hammers in a crusher are subjected to such punishing wear, Pennsylvania offers a hard-faced, forged-steel version which extends hammer life by as much as five times.

Many crusher models employ screen bars against which the hammers crush the coal. Pennsylvania developed these special profile bars to be self-cleaning to prevent clogging. The hard-faced version shown here increases the service life over ordinary bars by many times.

"Handbook of Crushing" available as free download

Learn more about the care and feeding of crushers with this his valuable, 42-page handbook, available for download (requires registration) from the Penn Crusher website. It provides a review of mechanical reduction methods and crusher selection criteria, with lots of illustrations, it also includes explanations and tables for the measurement of crushing resistance and relative abrasiveness.

A separate chart of abrasiveness indices lists over fifty minerals along with their numerical value and their site of origin. Yet another chart provides physical characteristics of numerous materials and minerals, coded according to abrasiveness, flowability and special characteristics. A typical product screen analysis report is also reproduced. Additional topics include power requirements for crushers, closed circuit crushing, crusher hammer types and other useful information, including an overview of all Pennsylvania crushers, sizers, breakers and feeders.

Where to find help to keep your crushers crushing

This is the last of three articles on crusher maintenance. I hope you've found these articles illuminating and perhaps you've gained some valuable tips that will save you time and money in the long run. See my previous article on the warning signs to listen for in a jaw crusher, and my first article on how to insure a longer life for ring hammers (granulators).

If you would like Pennsylvania Crusher to review your crusher maintenance procedures, or if you encounter service issues, please call me at 610-544-7200, or send your E-mail request to fschaffer@penncrusher.com. For more crusher information, visit Pennsylvania Crusher's website at www.penncrusher.com. You can learn more about our crusher services, parts and remanufacturing.

Fred Schaffer
Service Advisor
Pennsylvania Crusher

Comments

Post a comment