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Chapter 14: Mill Maintenance

Wheat Flour Milling, Second Edition
Pages 419-434
DOI: https://doi.org/10.1094/1891127403.014
ISBN: 1-891127-40-3


Maintenance can be defined as the activity undertaken to allow continued use of buildings and equipment over a desired life expectancy. Management wants full productivity from the production facilities at the minimum cost necessary to ensure their safe use. The key for efficient maintenance is good management of the resources invested in this activity.

The miller has always been concerned with maintenance. Historical mill pictures show the miller sharpening and grooving the millstones. More dependable stone quality, better roll steel, or durable sifting cloth gives the miller more time between maintenance activities and allows more efficient scheduling of maintenance and production. In the modern mill, the effort of maintaining the mill is not reduced but simply directed toward handling more sophisticated equipment.

The electronically controlled equipment and high-technology instrumentation used today is very dependent on the operational condition of the machines. Inadequate maintenance results in lost production time from breakdown failure, inefficient production, accelerated depreciation of plant facilities, wasteful application of lubricants, and increased insurance premiums. In addition, the miller must deal with the specific maintenance needed to guarantee product quality. The miller should keep a shut-down report that records lost production and the causes, e.g., mechanical, electrical, scheduling, or mill chokes.

Expenditures on maintenance cannot show direct returns, but they are very important for guaranteeing the overall return from the operation. One of the first things to examine when a mill is experiencing poor results is the maintenance. Roll corrugations and sieves gradually wear, and this is sometimes not noticed by the operator, who sees them every day. A regular maintenance schedule is necessary as well as an inspection program to evaluate maintained equipment.

The issue of spare parts in the mill is directly related to mill maintenance and cost. Based on management experience, mill location, logistics, and the cost of inventory, a decision should be made about the kind and number of spare parts needed to secure a good maintenance program. The inventory of spare parts should be watched closely by mill management, using appropriate computer software to keep a record of all changes.

The size of a maintenance department is in direct relationship to the size of the plant and its complexity. The cost of operating the department is directly related to the number of persons who are assigned to it and their qualifications.