Monday, December 31, 2007

Transport Equipment - Conveyors

An elaboration on Conveyors under the main point
'Transport Equipment' is as follows.


1. Chute Conveyor



Information:
  • Unit/Bulk + On-Floor + Accumulate
  • Inexpensive
  • Used to link two handling devices
  • Used to provide accumulation in shipping areas
  • Used to convey items between floors
  • Difficult to control position of the items

2. Wheel Conveyor



Information:
  • Unit + On-Floor + Accumulate
  • Uses a series of skatewheels mounted on a shaft (or axle), where spacing of the wheels is dependent on the load being transported
  • Slope for gravity movement depends on load weight
  • More economical than the roller conveyor
  • For light-duty applications
  • Flexible, expandable versions available


3. Roller Conveyor (2 types)

Information:
  • Unit + On-Floor + Accumulate
  • May be powered (or live) or nonpowered (or gravity)
  • Materials must have a rigid riding surface
  • Minimum of three rollers must support smallest loads at all times
  • Tapered rollers on curves used to maintain load orientation

3(a) Gravity Roller Conveyor



Information:

  • Alternative to wheel conveyor
  • For heavy-duty applications
  • Slope for gravity movement depends on load weight
  • For accumulating loads


3(b) Live (Powered) Roller Conveyor



Information:
  • Belt or chain driven
  • Force-sensitive transmission can be used to disengage rollers for accumulation
  • For accumulating loads and merging/sorting operations
  • Provides limited incline movement capabilities

4. Chain Conveyor


Information:
  • Unit + In-/On-Floor + No Accumulate
  • Uses one or more endless chains on which loads are carried directly
  • Parallel chain configuration used to transport pallets
  • Vertical chain conveyor used for continuous high-frequency vertical transfers (cf. vertical conveyor used for low-frequency intermittent transfers)
5. Slat Conveyor

Information:
  • Unit + In-/On-Floor + No Accumulate
  • Uses discretely spaced slats connected to a chain
  • Unit being transported retains its position (like a belt conveyor)
  • Orientation and placement of the load is controlled
  • Used for heavy loads or loads that might damage a belt
  • Bottling and canning plants use flat chain or slat conveyors because of wet conditions, temperature, and cleanliness requirements
  • Tilt slat conveyor used for sortation
6. Flat Belt Conveyor

Information:
  • Unit + On-Floor + No Accumulate
  • For transporting light- and medium-weight loads between operations, departments, levels, and buildings
  • When an incline or decline is required
  • Provides considerable control over the orientation and placement of the load.
  • No smooth accumulation, merging, and sorting on the belt
  • The belt is roller or slider bed supported; the slider bed is used for small and irregularly shaped items
  • In 1957, B.F. Goodrich, Co. patented the Möbius strip for conveying hot or abrasive substances in order to have "both" sides wear equally

7. Magnetic Belt Conveyor

Information:
  • Bulk + On-Floor
  • A steel belt and either a magnetic slider bed or a magnetic pulley is used
  • To transport ferrous materials vertically, upside down, and around corners
8. Troughed Belt Conveyor

Information:
  • Bulk + On-Floor
  • Used to transport bulk materials
  • When loaded, the belt conforms to the shape of the troughed rollers and idlers

9. Bucket Conveyor
Information:
  • Bulk + On-Floor
  • Used to move bulk materials in a vertical or inclined path
  • Buckets are attached to a cable, chain, or belt
  • Buckets are automatically unloaded at the end of the conveyor run
10. Vibrating Conveyor

Information:
  • Bulk + On-Floor
  • Consists of a trough, bed, or tube
  • Vibrates at a relatively high frequency and small amplitude in order to convey individual units of products or bulk material
  • Can be used to convey almost all granular, free-flowing materials
  • An Oscillating Conveyor is similar in construction, but vibrates at a lower frequency and larger amplitude (not as gentle) in order to convey larger objects such as hot castings
11. Screw Conveyor

Information:
  • Bulk + On-Floor
  • Consists of a tube or U-shaped stationary trough through which a shaft-mounted helix revolves to push loose material forward in a horizontal or inclined direction
  • One of the most widely used conveyors in the processing industry
  • Many applications in agricultural and chemical processing
  • Water screw developed circa 250 BC by Archimedes

12. Pneumatic Conveyor

Information:
  • Bulk/Unit + Overhead
  • Can be used for both bulk and unit movement of materials
  • Air pressure is used to convey materials through a system of vertical and horizontal tubes
  • Major advantages are that material is completely enclosed and it is easy to implement turns and vertical moves
12(a) Dilute-Phase Pneumatic Conveyor
Information:
  • Moves a mixture of air and solid
  • Push (positive pressure) systems push material from one entry point to several discharge points
  • Pull (negative pressure or vacuum) systems move material from several entry points to one discharge point
  • Push-pull systems are combinations with multiple entry and discharge points

12(b) Carrier-System Pneumatic Conveyor

Information:

Carriers are used to transport items or paperwork (e.g., money from drive-in stalls at banks)

13. Vertical Conveyor

Information:
  • Unit + On-Floor + No Accumulate
  • Used for low-frequency intermittent vertical transfers (cf. vertical chain conveyor can be used for continuous high-frequency vertical transfers
13(a) Vertical Lift Conveyor


Information:
  • Carrier used to raise or lower a load to different levels of a facility (e.g., different floors and/or mezzanines)
  • Differs from a freight elevator in that it is not designed or certified to carry people
  • Can be manually or automatically loaded and/or controlled and can interface with horizontal conveyors
13(b) Reciprocating Vertical Conveyor

Information:
  • Utilizes gravity-actuated carrier to lowering loads, where the load overcomes the magnitude of a counterweight
  • Can only be used to lower a load
  • Alternative to a chute conveyor for vertical "drops" when load is fragile and/or space is limited
  • Can be manually or automatically loaded and/or controlled and can interface with horizontal conveyors
14. Cart-On-Track Conveyor

Information:
  • Unit + In-Floor + Accumulate
  • Used to transport carts along a track
  • Carts are transported by a rotating tube
  • Connected to each cart is a drive wheel that rests on the tube and that is used to vary the speed of the cart (by varying the angle of contact between the drive wheel and the tube)
  • Carts are independently controlled
  • Accumulation can be achieved by maintaining the drive wheel parallel to the tube
15. Tow Conveyor
Information:
  • Unit + In-Floor + Accumulate
  • Uses towline to provide power to wheeled carriers such as trucks, dollies, or carts that move along the floor
  • Used for fixed-path travel of carriers (each of which has variable path capabilities when disengaged from the towline)
  • Towline can be located either overhead, flush with the floor, or in the floor
  • Selector-pin or pusher-dog arrangements can be used to allow automatic switching (power or spur lines)
  • Generally used when long distance and high frequency moves are required
16. Trolley Conveyor
Information:
  • Unit + Overhead + No Accumulate
  • Uses a series of trolleys supported from or within an overhead track
  • Trolleys are equally spaced in a closed loop path and are suspended from a chain
  • Carriers are used to carry multiple units of product
  • Does not provide for accumulation
  • Commonly used in processing, assembly, packaging, and storage operations
17. Power-And-Free Conveyor

Information:
  • Unit + Overhead/On-Floor + Accumulate
  • Similar to trolley conveyor due to use of discretely spaced carriers transported by an overhead chain; however, the power-and-free conveyor uses two tracks: one powered and the other nonpowered (or free)
  • Carriers can be disengaged from the power chain and accumulated or switched onto spurs
  • Termed an Inverted Power-and-Free Conveyor when tracks are located on the floor
18.Monorail
Information:
  • Unit + Overhead + Accumulate
  • Overhead single track (i.e., mono-rail) or track network on which one or more carriers ride
  • Carriers: powered (electrically or pneumatically) or nonpowered
  • Carrier can range from a simple hook to a hoist to an intelligent-vehicle-like device
  • Single-carrier, single-track monorail similar to bridge or gantry crane
  • Multi-carrier, track network monorail similar to both a trolley conveyor, except that the carriers operate independently and the track need not be in a closed loop, and a fixed-path automatic guided vehicle (AGV) system, except that it operates overhead
  • Termed an Automated Electrified Monorail (AEM) system when it has similar control characteristics as an AGV system
19. Sortation Conveyor

Information:
Unit + On-Floor/Overhead

Sortation conveyors are used for merging, identifying, inducting, and separating products to be conveyed to specific destinations

19(a) Sortation Conveyor: Diverter
Information:
  • Stationary or movable arms that deflect, push, or pull a product to desired destination
  • Since they do not come in contact with the conveyor, they can be used with almost any flat surface conveyor
  • Usually hydraulically or pneumatically operated, but also can be motor driven
  • Simple and low cost
19(b) Sortation Conveyor: Pop-up Device
Information:
  • One or more rows of powered rollers or wheels or chains that pop up above surface of conveyor to lift product and guide it off conveyor at an angle; wheels are lowered when products not required to be diverted
  • Only capable of sorting flat-bottomed items
  • Pop-up rollers are generally faster than pop-up wheels
19(c) Sortation Conveyor: Sliding Shoe Sorter
Information:
  • Sliding shoe sorter (a.k.a. moving slat sorter) uses series of diverter slats that slide across the horizontal surface to engage product and guide it off conveyor
  • Slats move from side to side as product flows in order to divert the product to either side
  • Gentle and gradual handling of products

19(d) Sortation Conveyor: Tilting Device
Information:
  • Trays or slats provide combined sorting mechanism and product transporter
  • Can accommodate elevation changes
  • Tilt tray sorters usually designed in continuous loops with a compact layout and recirculation of products not sorted the first time
  • Tilt slat sorters carry products on flat-surface slat conveyor and can handle wider variety of products compared to tilt tray

19(e) Sortation Device:
Information:
  • Either continuous loop, where individual carriages are linked together to form an endless loop, or train style (asynchronous), where a small number of carriers tied together with potential for several trains running track simultaneously
  • Each carriage equipped with small belt conveyor, called the cell, that is mounted perpendicular to direction of travel of loop and discharges product at appropriate destination
  • Automatically separates single line of products into multiple in-line discharge lines

source info: http://www.ise.ncsu.edu/kay/mhetax/TransEq/Conv/index.htm