Page 263 - Root Cause Failure Analysis

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CONVEYORS

Conveyor failure modes vary, depending on the type of system. Two common types of
conveyor systems used in chemical plants are pneumatic and chain-type mechanical.

PNEUMATIC

Table 2 1-1 lists common failure modes associated with pneumatic-conveyor systems.
However, most common problems can be attributed to either conveyor piping plug-
ging or problems with the prime mover (Le., fan or fluidizer). For a centrifugal fan
troubleshooting guide, refer to Table 20-1. For fluidizer and blower guides, refer to
Table 20-2.

CHAIN-TYPE MECHANICAL
The Hefler-type chain conveyor is a very common type of mechanical conveyor used
in integrated chemical plants. Table 21-2 provides the more common failure modes of
this type of conveyor. Most of the failure modes defined in the table can be attributed
directly to operating practices, changes in incoming product quality (Le., density or
contamination), or maintenance practices.

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