Conveyor Operations

Conveyor Operations

Load Characteristics: Surface condition of product should have a smooth and firm bottom for efficient conveyability.  As Specialty items such as rolls of cloth or carpet may be conveyed on a “troughed roller” arrangement which forces the object to run down the center of the conveyor. In this instance, use of solid formed guard rails is imperative.

Operating Conditions: Special conditions dictate any modifications required for normal unit operation. A conveyor used in a wet or wash down application, foundry, oven or freezer will require special features that normally would not be required when operated in a clean dry ambient room environment.

Roller Capacity: Once the number of rollers required to convey the minimum package length is determined, roller capacity must be determined. Divide the maximum weight per linear foot by the number of rollers required per foot. The minimum required capacity per roller results.

Example: 18″ long package weighs 800 lbs. 800 / 18 x 12 = 534 lbs. per foot.

534/4 = 134 lbs. minimum roller capacity for 3″ roller centers when a minimum  of  rollers are required to carry the minimum package length.

534/3 = 17 lbs. minimum roller capacity for 4″ roller centers when a minimum of 3 rollers are required to carry the minimum package length.

NOTE: Additional rollers (or high capacity rollers) are required to support load when product loading is unevenly distributed.

Frame Capacity: After the roller capacity is determined, unit frame capacity must be calculated. Multiply the maximum product loading per linear foot by the conveyor length to determine the required frame capacity. The minimum required frame capacity results.

Example: Max. product load per foot is 250 lbs.

250 lbs. / ft. max. load x 10 = 2500 lbs. total live load per 10′ section.

Shock Loading: Shock loading  (i.e. loading from fork truck, or dropping load onto conveyor) places a great deal of stress on both conveyor rollers and frame. Therefore in instances where conveyor is subject to shock loading, provisions must be made to deal with this high stress loading. Rollers with greater capacity, heavier duty rollers and/or heavier gauge frame construction is required to offset this special loading condition.

Curves:
A. Straight Face Rollers: Straight face rollers are recommended where packages of uniform size are conveyed and rubbing against guards is not objectionable. Package orientation may be affected.

B. Differential Rollers: Differential Rollers offer reduced package swerve (when compared to a straight roller curve) and packages travel more easily. Guard rail should be used.

C. Tapered Rollers: Tapered rollers are recommended above all others because of their improved carrying surface. They hold the package in relatively the same position through the entire curve. Guards are normally used on the outside curve rail.

Curve Radius: There are various methods used to identify the point where radius is measured on Roach curves. Curve radius locations vary by individual manufacturers.

Curve Width: Once the appropriate curve has been selected, curve width must be determined. Lengthy objects will require special consideration. As a general rule of thumb the package length should not exceed the inside radius dimension (this will not be a factor if the BF is wide enough). It is recommended there-fore, to maintain a greater inside radius than the longest package length conveyed.

Supports:
A. Tripods: Tripods are used on light duty conveyors in portable or temporary applications. Tripods are not recommended for application using medium duty conveyors. When installing tripods, the top channel of the tripod assembly rests in the frame conveyor cross brace.

B. Permanent Floor Supports: Permanent “H-type” floor supports are the most common means of supporting conveyors. A full support is used to span intermediate bed sections where adjoined and at each end of a unit. Additional supports are required only when additional capacity is required to support the frame in extreme conditions or when a normal support location is blocked by other machinery (or similar instances). Single leg permanent floor supports are also available.

C. Ceiling Hangers: Ceiling hangers are commonly used in high elevation applications or when it is not practical to install permanent floor supports (aisles, walkways, etc.)

CAUTION: When using ceiling hangers at 7′ and above installed elevation, it is imperative that high solid guard rail is used to hold product on conveyor and that safety pop out rollers are retained in the conveyor frame.

D. Polytier Supports:
When two or  more tiers of conveyor must be installed, use polytier supports. Each set of legs is supplied with cross pipes and one pair of knee braces (standard) to support multiple tiers of conveyors. In minimum elevation applications, hardware is available for installation at frame depth + 0.

E. Undertrussing:
For installation of some conveyors, a full support or ceiling hanger cannot be used to maintain necessary clearances underneath unit or for other. In these instances, use of unit undertrussing may be a viable alternative. Tow bed sections or a total of 32′ may be undertrussed.