Avoiding the pulveriser

ContiTech has developed an air actuator with fewer moving parts designed to avoid wear inside a coal pulveriser.

The conditions inside a coal pulveriser can be very harsh, with coal dust and vibrations placing a large amount of strain on materials.

It is this strain that can wear down the resistance of both materials and machinery.

According to ContiTech Air Spring Systems, their air actu­ators are able to last much longer than hydraulic powered steel cylinders as they are more resist­ant to the conditions inside a coal pulveriser.

“The steel cylinders can not stand up to the coal dust and the oily environ­ment for longer than three months,” the company said.

“Nitrogen-operated air actu­ators used in coal pulverisers, on the other hand, have proven themselves under adverse con­ditions.”

Air actuators are dimen­sionally stable elements made of elastomer materials with vulcanised textile tensile


The reason for their ability to withstand the wear of the coal pulveriser is that air actu­ators are designed to function mainten­ance and oil-free and without sliding gaskets.

Essentially, Con­tiTech says that the fewer moving parts, the fewer instances of wear.

“As they function with­out mechani­cally moving parts, the air actuators are wear and main­tenance free,” the company said.

“Dirt, dust, granu­lated material and sludge can­not damage the air actuator, and it is also completely resistant to many chemicals.”

While Conti­Tech produces many air actuator de­signs, they can be split into two basic variants: convolution air springs and rolling lobe air springs.

Single, double and triple convolution air springs have a very low minimum height and low return forces.

Compared to convolution air springs, rolling lobe air springs have a smaller diame­ter but the same maximum force, and emit an almost con­stant level of force via the stroke.

With air actuators designed for pneumatic functions, the movement is generated by the bending of a highly flexible shell which according to the company, means the usual piston rods and the guiding and sealing elements are not required

Standard actuators are designed for temperatures from -30°C to 70°C and there are also designs for much hotter or cooler operating conditions, ranging from -60°C to 130°C peak temperature, ContiTech said.

• ContiTech Air Spring Systems

02 8901 0553


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