To ensure that you are getting the highest efficiency from your spiral freezer, it is necessary to go beyond the obvious maintenance techniques such as greasing bearings and performing preventive maintenance as well as adhering to factory-supplied maintenance schedules. It is -30oF (-34oC) in that freezer, so it is no picnic to have to spend a significant amount of time in there.
Think Outside the BoxThere are several factors to consider when it comes to spiral freezers.
Focus on the Uptime Line Efficiencies of the Spiral Freezer Unit. These can be calculated by taking the total number of hours the whole line runs in a 24-hr period and subtracting sanitation and changeover times (assuming the line is not dedicated to a single product). An example might be a 16-hr shift operation running with a 2-hr sanitation time and two product changes, which take 30 min each. The available time for the freezer is 13 hr, and of this time, the unit should be capable of producing saleable product at least 90 percent of the time. Unscheduled downtime for a freezer should not be an accepted practice if you want to maintain a high overall line efficiency rating.
Do What It Takes to Eliminate Waste. A commonly accepted practice is to allow for a scrap percentage. This can be from product ramping up on the freezer or from operational fluctuations such as coil inefficiencies (icing and frost on coils), which create unsaleable products. With a proper maintenance plan and personal commitment to the freezer, these can be minimized or eliminated.
Don't Use Human Resources Where They Aren't Needed. Your people should not be placing or arranging products on the infeed or discharge sides of the freezer. This is a waste of human resources that can be corrected easily with the proper conveyor transfers or other mechanisms that allow hands-free processing.
Get More When You BuyIt goes without saying that you should follow the freezer manufacturer's schedule for maintenance. But, you can make your freezer operate even better by helping the manufacturer design a system that takes into account both the latest technology in design and your specific needs. Addressing these needs up front helps with maintenance after the freezer is installed and operating.
Before buying a new system, listen to your employees' ideas and incorporate them into a plan. This plan should review each critical point of the freezer where improvements can be made, including sanitation, airflows, air temperatures, box openings and coil location in relation to openings, to name a few. Do not rely solely on the freezer supplier. Your freezer should be totally unique to your product and production needs, and should not be made as an off-the-shelf item.
Consider the best maintenance and safety procedures, and be sure they are incorporated into your process. Reducing maintenance costs will help increase production uptime, producing more saleable products per hour.
Get More When You OperateOnce you have purchased your spiral freezer, don't just forget it. No matter how well it is engineered, the human element plays an important role in keeping the system in tip-top shape. Although a bit unorthodox, there are steps you can take that will benefit production by creating good morale and, by extension, good performance. For instance:
- Give the freezer a name.
- Assign a single person per shift to look after the freezer.
- Get the freezer manufacturer to personally train this employee on the operation, maintenance, safety and sanitation of the freezer.
Also, consider who will have to operate and maintain the system when specifying it. Simple changes in the design stage can pay big dividends later. For example:
- Group your bearings for greasing as much as possible.
- Keep your belt clean to protect your investment. Problems due to dirty tracks are the single largest cause of belt complaints on a spiral freezer. Belts can look clean, but if the tracks they ride on are not cleaned, it is a waste of resources.
- Get your refrigeration person involved to make sure that the heart of the system (which is the refrigeration and not the spiral) is performing to its maximum capacity and at its most economical cost per hour of operation.
If you follow the above guidelines for operation, maintenance should fall right into place.
Get More When You MaintainMost spiral freezer systems that are operating poorly have definite signs of maintenance and upkeep problems that result in less product output. As maintenance and operational costs go up, your profits and product quality go down. When there is ice buildup on the coils, which has a negative impact on your freezing capacity, and products are blowing off the spiral belt and onto the floor (wasted products, loss of profits), you should address some simple but effective solutions to eliminate the problems.
For instance, reduce icing and frost buildup. These are signs of air infiltration -- hot going to cold -- and can be minimized by either balancing the air or closing off larger-than-needed openings. Coils that are operated under continually frosted coverage are doing so with less capacity and more strain, causing less production output and higher operating costs on the system due to more work required on the high side equipment of the freezer. While newer freezer designs allow for this, a problem with existing freezer units is more difficult to solve. A proactive approach is to measure the production output on a charted basis to define when this production output loss occurs, and then get together with your local refrigeration expert to come up with a way to keep the frosting of the coils to a minimum.
To get more out of your spiral freezer, walk through it and check the following:
- Coils inside the box are operating as near as frost free as possible.
- Openings in the box are closed off (except for the belt going in/out).
- Suction temperatures are operating in the range for which they were designed and installed.
- Belt track supports are kept clean (to protect that costly belt you purchased).
- Bearings are grouped properly for greasing.
- Belt cleaners are operating at a high efficiency level (getting most of debris off the belt).
To get the most out of your freezer, you must be willing to invest a little time and money. Follow the above suggestions and you should see reduced maintenance costs, increased production output and a heftier bottom line.