Feed Mill and Equipment Maintenance
May 01, 1997
by Teresa Acklin
A practical guide to developing and managing an effective maintenance program
Proper maintenance of feed manufacturing facilities and equipment improves feed quality and operational efficiency, reduces the likelihood of feed contamination and helps ensure safe meat, milk and eggs destined for human consumption.
A number of countries have developed feed processing guidelines, referred to as Good Manufacturing Practices (GMPs), that are designed to prevent feed contamination and provide reasonable assurance that feed is manufactured accurately. The guidelines often serve as the foundation for official government regulations.
GMPs address a variety of points that manufacturers should follow to assure safe and efficient feed manufacturing. These points range from landscaping and construction of the facility to proper procedures for managing equipment maintenance.
Following GMPs, buildings and grounds must be constructed and maintained to prevent the contamination of feed by rodents, insects, birds, nonfeed additives, chemicals, lubricants, dangerous foreign material such as glass and moisture.
Grain bins, hatches, lids, augers and terrain around the bin should all prevent moisture from entering the grain and feed components. Feed ingredients must be protected from excess moisture to avoid contamination by mold that can possibly produce harmful toxins and reduce palatability.
Rodents, birds and insects potentially can spread disease through feces, urine and body parts such as feathers or hair. They can cause grade reductions, and they can consume significant amounts of feed ingredients. Roofs, walls, doors and floors of feed manufacturing and storage facilities should be designed and maintained to prevent entry of these pests.Equipment
Under GMPs, feed processing equipment must be designed, maintained and operated in such a manner to ensure accuracy in ingredient proportioning and adequate processing.
A plan to regularly check or service equipment and make necessary repairs on a scheduled basis will more than pay for itself when compared with having to do the same work in a crisis or hurried situation. As a general rule, for every U.S. dollar spent on preventive maintenance, you will save at least U.S.$5 in subsequent expenses.
Maintenance is defined as the proper planning and action to minimize and avoid breakdowns and lost time. Maintenance includes a prepared and organized plan to return operations to normal in as short a time as possible if an incident does occur.
Maintenance can be divided into four different types. Routine maintenance consists of servicing equipment on a scheduled basis. This may consist of activities such as lubrication of bearings, replacing hammermill screens, turning or replacing hammers, checking drive V-belts and checking oil levels in gear boxes.
Emergency maintenance entails reacting to unscheduled breakdowns. This maintenance must be done immediately and supersedes all other types.
Call-in maintenance usually involves an emergency situation where the people required are not at hand and must be summoned from somewhere else, such as a millwright service or contractor.
Preventive maintenance consists of scheduled inspections and making adjustments and repairs to equipment to make sure it is in proper working order. This includes replacement of worn parts prior to failure, based on observed conditions or known useful life spans.Specific Procedures
The first step in developing a maintenance program entails collecting good information and organizing it in a useful form. This information may be gathered under the following headings:
1. Equipment identification
2. Equipment information
3. Equipment maintenance requirements
4. Parts inventory
5. Maintenance records At some point, every piece of equipment in the feed mill will need maintenance of some type. In order to track the frequency of maintenance needed and its type and cost, each piece of equipment must be identified in some manner.
Each piece of equipment should have its own identification number. An easy way to accomplish this is to draw a flow of the entire feed milling process showing each piece of equipment along with its identification number (see figure on pages 16-17).
It also may be desirable, in larger plants, to not only identify the equipment by number, but also by system, cost center or physical location. An example would be “A-RE-1,” which says receiving conveyor number 1 is located in building or area A.
Once the decision has been made on how to assign identification numbers to the equipment, it is necessary to prepare a master list of the equipment showing each identification number and the piece of equipment it identifies (see Chart 1).
An equipment identification system is useless unless it is used to obtain and keep information about each machine. This is most easily done by filling out an information sheet on each piece of equipment (see Chart 2).
The information may be gathered from operating manuals, purchase records, visual inspection, supplier information or other sources. The information should include not only key part data and sizes, but also a supplier code to show where parts may be found. This code could indicate a supplier's name, address and phone number; or if the part is in plant inventory the code may just say “inv.” Separate supplier code pages should be used for each letter of the alphabet (see Chart 3).
Each manufacturer can provide recommended routine maintenance procedures and schedules for the equipment supplied. This information may be found in installation and operating manuals, catalogs or by direct contact with the supplier.
Lubrication frequencies depend on operating conditions and time intervals. The equipment supplier, or your lubricant supplier, can suggest proper scheduling intervals and amounts to be used (see Chart 4).
Regular equipment checking and maintenance also will help to identify proper preventive maintenance scheduling and types. Emergency maintenance situations, especially as a history is developed for a machine, will determine routine and preventive maintenance scheduling.
Maintenance procedures, except for emergency maintenance, should be tied to a calendar to ensure that required maintenance occurs as scheduled (see Chart 5).Parts Inventory and Records
It would be wonderful if every time an emergency maintenance situation occurred, the necessary parts were on hand and available. Unfortunately, no company can afford the cash outlay it would require for the parts. A sensible approach to the parts inventory situation is to classify parts into three categories:
1. Critical hard-to-get parts
2. Parts readily available from a supplier
3. Parts needing sufficient time to order
Parts that are crucial or hard to get should be kept on hand or where they can be immediately obtained. Noncritical parts may be ordered from suppliers as needed.
On the equipment information sheets (see Chart 2 on page 18), you may want to include a required availability code by each part or piece of equipment. A suggested coding might be:
I = On hand (plant inventory)
S = On hand at supplier
O = must be ordered.
The parts in plant inventory will be determined by how often they are needed. Routine, preventive and emergency maintenance records will help identify availability requirements for parts.
As maintenance work is performed, a separate record of what was done, parts required, labor required, special equipment required and other cost items should be maintained. A total cost for each maintenance operation should be figured and shown on the record form (see Chart 6).
This information soon will establish the maintenance cost for each machine, and it will indicate potential and continuing trouble spots. The information also will reveal how often preventive maintenance should be scheduled and what should be done to avoid emergency maintenance situations.
Equipment and maintenance records help in making decisions about repairing or replacing equipment or even eliminating an operation or process.
This article is based on a bulletin written by Fred Fairchild, extension specialist, feed manufacturing, Department of Grain Science and Industry, Kansas State University, Manhattan, Kansas, U.S.