131

Larger blending ratios of imported coal and non-uniform blending can result in?

v  Slagging and fouling in the furnace

v  Higher temperatures near coal burners resulting in boiler tube leakages etc.

132

What are the precautions to be followed while using Imported Coal?

v  Imported coal to be stocked in layers of 1.0 m to 1.5 m and compaction of each such layer with dozer to be done in order to avoid auto-ignition of stacked coal

v  Loose un-compacted coal on sides of yard to be removed partially and compaction to be done again to avoid sliding on the tracks of stacker reclaimer 

v  Coal stockyard to be covered with polythene sheets during rainy season 

133

What is Operations and Maintenance?

Operations and Maintenance are the decisions and actions regarding the control and upkeep of property and equipment. 

These are inclusive, but not limited to, the following:

v Actions focused on scheduling, procedures, and work/systems control and optimization; and

v Performance of routine, preventive, predictive, scheduled and unscheduled actions aimed at preventing equipment failure or decline with the goal of increasing efficiency, reliability, and safety.

134

What is elasticity?

Elasticity is the tendency of solid materials to return to their original shape after being forces are applied on them.

When the forces are removed, the object will return to its initial shape and size if the material is elastic.

135

What is viscoelasticity?

Viscoelasticity is the property of materials that exhibit both viscous and elastic characteristics when undergoing deformation.

Synthetic polymers, wood, and human tissue, as well as metals at high temperature, display significant viscoelastic effects.

136

List some uses of viscoelastic material?

Viscoelastic materials are used for isolating vibration, dampening noise, and absorbing shock.

They give off the energy absorbed as heat.

137

What is plasticity?

Plasticity is the general property of all materials that are able to irreversibly deform without breaking.

Plastic is a material consisting of any of a wide range of synthetic or semi-synthetic organics, that are malleable and can be molded into solid objects of diverse shapes.

Plastics are typically organic polymers of high molecular mass, but they often contain other substances. They are usually synthetic, most commonly derived from petrochemicals, but many are partially natural.

138

What are the two types of plastics?

There are two types of plastics are thermoplastics and thermosetting plastics.

139

What are thermoplastic materials?

Thermoplastic materials are the plastics that do not undergo chemical change in their composition when heated and can be molded again and again.

Examples include polyethylene, polypropylene, polystyrene and polyvinyl chloride.

140

What are thermoset plastic materials?

Thermoset plastics can melt and take shape once.

After they have solidified, they stay solid.

In the thermosetting process, a chemical reaction occurs that is irreversible.

The vulcanization of rubber is a thermosetting process.