Oscillating Conveyor System

Selection of vibratory conveyor:

The oscillating motion of the trough is achieved via specially designed inclined arms and an eccentric shaft driven by a motor through V-belts. The eccentric shaft is mounted on anti friction bearings and has V-pulleys at both ends with weights on them to counteract the unbalancing force. The rotation of the eccentric shaft provides a forward and backward motion to a connecting arm attached to the trough through a rubberized pin. The trough motion is predominantly horizontal with some vertical component, which causes it to oscillate with a pattern conductive to conveying material. A retaining spring assembly at the back of the trough absorbs shock load. All components including drive motor are mounted on a rigidly constructed base frame.

Advantages:

· Hot and abrasive materials can be handled

· Cooling, drying and de-watering operation can be done during transport

· Scalping, screening or picking can be done

· Units can be covered and made dust tight

· Simple construction and low head room

· Can be made leak proof

Disadvantages:

· Relatively short length of conveying ( about 50m Maximum)

· Limited capacity, about 350 tons per hour for length of conveying of 30 m.

· Some degradation of material takes place.

Applications:

Vibratory conveyors find wide spread application in the transportation of dusty, hot, toxic, and chemically aggressive bulk material through a closed trough or pipe in chemical, metallurgical, mining industries and manufacturing of building materials.

Vibratory conveyors are also employed for transportation of steel chips in machine shop, hot knocked out sand, wastes and small castings in foundry shop. Vibratory feeders are also in use for delivery of small machine parts like screws, rivets etc.

Sticky materials like wet clay or sand are unsuitable for vibratory conveyors. In handling finely pulverized materials, like cement etc., the performance of such conveyors are reported to be poor.

Vibratory conveyors are hardly employed for handling common bulk loads, such as sand, gravel, coal etc as the same can be done more efficiency by belt conveyors.

JIB CRANE

Jib crane have the following motions:

1. Hoisting motion
2. Derricking or luffing motion
3. Slewing motion
4. Long travel motion

Hoisting motion:

It is used to lift or lower the load. This is usually achieved by steel wire ropes being affixed to a crane hook or a grab hanging from the outer end of the jib. The rope is applied through some receiving arrangement and controlled and operated by a winch system.

Derricking or Luffing motion:

It is imparted to the inclined member or the jib to move in a vertical plane so that the angle of the jib may be changed in order to bring the load line nearer to or further off from the centre of the crane.

Slewing motion:

It is imparted to the whole super structure of the crane including the jib, so that it can turn about a central pivot shaft w.r.t. the non-revolving parts. This motion enables the crane to shift the load line to revolve round the crane.

Long Travel Motion:

It may be required when the whole crane structure has to be shifted to a distant place along a rail track or along a road.

Jib crane consists of an inclined member supported by a rope or any other type of structural member attached to a vertical mast or frame. Load is usually suspended from the outer end of this inclined mast. The outreach of the jib may be fixed or variable. The cranes as a whole may be either fixed or moveable. Various sub-classification of these cranes are possible.

Lifting capacity of such cranes may vary from 1/2 ton to 200 ton and outreach from a few meter to 50 meter. Such cranes find various applications in port area, construction site, and other outdoor works.

For handling general cargo, lifting capacities are usually 1  1/2 ton to  5 ton with maximum outreach of 30 meter. Jib Cranes provided with grabbing facilities have usually a capacity ranging from 3 to 20 tons operating 50 to 100 cycles per hour. Lifting heights may be 30 meters or more.

Jib crane used in ship yards for lifting heavy machinery and equipment, weighing 100 to 300 tons, are usually mounted on pontoons. Frequently these cranes are provided with two main hoisting winches which can be employed singly or together to lift a load. For handling light loads these cranes may have auxiliary arrangement.

Types Of Jib Crane:

Depending on the use, jib cranes are classified into a number of varieties, primarily on the basis of their mountings.

These are:

1. Hand Operated Scotch Derrick Type
2. Wall Mounted Jib crane
3. Portal / Semi-portal cranes of different varieties-Wharf cranes
4. Mobile jib cranes consisting of truck mounted and crawler mounted cranes

Scotch Derrick Type / Wall Cranes:

Wall cranes are used in ware houses for handling light weight and when there is little or no wharf between them and the water front. Slewing or rotational motion of the crane is possible within restricted angle and the motion is slow. Hoisting and lifting speeds are comparable to those of wharf cranes. In some modified version these cranes can have travelling speed along the wall.

Wharf Cranes:

These are used in shipyard and port for handling unit and bulk load. These are usually self propelled balanced level luffing type with full circle slewing motion facility. Wharf cranes may be of different types, depending on the type of structure on which it is mounted.  The choice of structure for mounting depends on site condition.

The principal types of wharf cranes are:

• High pedestal
• Full Portal
• Semi-portal

Portal Cranes:

Portal crane is a fixed or revolving type jib crane mounted on a portal frame fixed in location or arranged to travel along a fixed track of rails at the same level. The portal frame consists essentially of horizontal girders connected at both ends to vertical or inclined member’s having equal lengths.

Semi portal Crane:

Semi portal crane is a fixed or revolving type jib crane mounted on a semi portal frame fixed in location or arranged to travel along a fixed track or rails at different levels. The semi portal frame essentially consists of horizontal girders connected at both ends to vertical or inclined members which constitute a shorter side and a longer side. The shorter members may consist only of the trolley running along the elevated rail.

Mobile crane:

Mobile Crane ( Power Driven ) includes all type of travelling jib cranes, such as truck mounted, crawler mounted, locomotive crane on rails.

 

X RAY DIFFRACTION

It’s useful for studying Crystal structure

This method have the details about

• Grain size (or) Crystal size
• Orientation of the crystal
• Cold worked, Distorted and Internally stressed crystals
• Re-Crystallization
• Preferred orientation etc

Methods of Examining and Measuring the condition of Crystal Structure

1. The Laue back reflection method
2. The Rotating Crystal method
3. The DeBye- Scherrer (or) Powder method:

The Laue back Reflection method:

It’s applicable to single crystals (or) poly-Crystalline masses.

When a beam of Mono chromatic (i.e. of Single Wavelength) X-Ray is directed as a narrow pencil at a specimen of a metal diffraction takes place at certain of the crystallographic planes.

The Rotating Crystal method:

It’s a useful method for determining angles and positions of planes.

Crystallographic planes are brought in to reflecting positions by rotating a crystal (Specimen) about one of it’s axis while simultaneously radially it with a beam of mono chromatic x-Rays.

If crystal orientation planes are known, the angles and directions can be calculated.

The DeBye- Scherrer (or) Powder method:

The narrow pencil of monochromatic X-Rays is diffracted from the powder and recorded by the photographic film as a series of lines of varying armature.

By the Bragg Equation:

nλ=2d Sinθ

Where,

λ– Wave length of X-ray

d- Spacing of the atomic planes

θ – Angle of reflection

 

 

 

 

 

X RAY DIFFRACTION

It’s useful for studying Crystal structure

This method have the details about

• Grain size (or) Crystal size
• Orientation of the crystal
• Cold worked, Distorted and Internally stressed crystals
• Re-Crystallization
• Preferred orientation etc

Methods of Examining and Measuring the condition of Crystal Structure

1. The Laue back reflection method
2. The Rotating Crystal method
3. The DeBye- Scherrer (or) Powder method:

The Laue back Reflection method:

It’s applicable to single crystals (or) poly-Crystalline masses.

When a beam of Mono chromatic (i.e. of Single Wavelength) X-Ray is directed as a narrow pencil at a specimen of a metal diffraction takes place at certain of the crystallographic planes.

The Rotating Crystal method:

It’s a useful method for determining angles and positions of planes.

Crystallographic planes are brought in to reflecting positions by rotating a crystal (Specimen) about one of it’s axis while simultaneously radially it with a beam of mono chromatic x-Rays.

If crystal orientation planes are known, the angles and directions can be calculated.

The DeBye- Scherrer (or) Powder method:

The narrow pencil of monochromatic X-Rays is diffracted from the powder and recorded by the photographic film as a series of lines of varying armature.

By the Bragg Equation:

nλ=2d Sinθ

Where,

λ– Wave length of X-ray

d- Spacing of the atomic planes

θ – Angle of reflection