MATERIAL HANDLING

Bases on Design features and operational characteristics, material handling equipment may be broadly classified as:

Hoisting Equipment’s:

It constitute a group of equipment which are employed mainly for lifting or lowering of unit load or piece goods in batches. This group of equipment’s can be further sub classified into:

1. Pure Hoisting Machineries

• Jack
• Winches
• Hand Hoists
• Pulley Blocks

2. Cranes

• EOT Crane
• Jib Crane
• Cantilever Crane

3. Elevators

• Lift
• Bucket Elevators

Conveying Equipment’s:

It comprises of a number of equipment which are employed for handling principally bulk load (occasionally piece goods or unit load may also be handled) in continuous flow. Such machines do not have separate lifting or lowering gear. This group of equipment also can have further sub classifications as:

1. Belt Conveyor

2. Hydraulic Conveyor

3. Pneumatic Conveyor

4. Apron Conveyor

5. Screw Conveyor

6. Flight Conveyor

Surface/ Overhead Equipment’s:

These are the group of equipment’s which are employed for handling unit load or bulk load in batches on a horizontal surface. This group of equipment may be further sub classified into:

1. Truck and Lorries

2. Railway Cars and Wagons

3. Fork Lifts

4. Overhead mono-rail / Equipment

5. Scrapers and Skidders

Types of Material Handling Equipment Loads:

It usually classified into:

1. Unit Load

2. Bulk Load

Unit Load:

Unit loads are those which are counted by numbers or units. A component of a machine, a complete machine, a structural element, a beam, a girder, building block are some examples of unit load.

Sometimes certain quantities of free flowing materials can be placed in a container and can be handled as unit load. Hoisting equipment are primarily used for handling unit load. Unit loads are usually specified by it’s weight.

Bulk Load:

When the load is in the form of particles or lumps of homogeneous materials or powder like materials, which can not be counted by numbers, it is called as “Bulk load”.

Examples are:

Sand, Cement, Coal, Mineral, Stone, Clay etc.,

A bulk material may be classified by it’s:

1. Bulk Density

2. Lump-Size

3. Flowability

4. Abrasiveness

5. Miscellaneous Characteristics

INTERVIEW QUESTIONS:GERNAL:

• Explain the Second Law of Thermodynamics.
  The entropy of the universe increases over time and moves towards a maximum value.

 

• How do you measure temperature in a Wet Bulb Thermometer?
  Wet bulb temperature is measured in a wet bulb thermometer by covering the bulb with a wick and wetting it with water. It corresponds to the dew point temperature and relative humidity.

 

• What is Bending moment?
  When a moment is applied to bend an element, a bending moment exists in the element

 

• What are the points in the Stress Strain curve for Steel?
  Proportional limit, elastic limit or yield point, ultimate stress and stress at failure.

 

• Define Reynolds number.
  Reynolds number is the ratio of inertial force and viscous force. It is a dimensionless number. It determines the type of fluid flow.

 

• What is a Newtonian fluid?
  A Newtonian fluid possesses a linear stress strain relationship curve and it passes through the origin. The fluid properties of a Newtonian fluid do not change when any force acts upon it.

 

• How many Joules is 1 BTU?
  1 BTU is equal to 1055.056 joules.

 

• What is PS?
  PS is Pferdestarke, the German unit for Horsepower.

 

• Explain Otto cycle.
  Otto cycle can be explained by a pressure volume relationship diagram. It shows the functioning cycle of a four stroke engine. The cycle starts with an intake stroke, closing the intake and moving to the compression stroke, starting of combustion, power stroke, heat exchange stroke where heat is rejected and the exhaust stroke. It was designed by Nicolas Otto, a German engineer.

 

• Explain the nomenclature of a 6203-ZZ bearing.
  6 is the type code, which shows it is a single-row ball bearing, 2 is the series, means light, 03 is the bore, which is 17 mm and ZZ is the suffix meaning double shielded bearing.

 

• What is Gear ratio?
  It is the ratio of the number of revolutions of the pinion gear to one revolution of the idler gear.

 

• What is Annealing?
  It is a process of heating a material above the re-crystallization temperature and cooling after a specific time interval. This increases the hardness and strength if the material.

 

• Define Torque.
  Torque is defined as a force applied to an object that results in rotational motion.

 

• What is Ductile-Brittle Transition Temperature?
  It is the temperature below which the tendency of a material to fracture increases rather than forming. Below this temperature the material loses its ductility. It is also called Nil Ductility Temperature.