The type and viscosity of food product, thermal processing technology, desired texture, and cooking/processing cycle times are considerations for the applied cooking/blending solution. When selecting an agitator or changing an application, review the thermal processing and blending goals. The proper agitator selection, blending action and recipe controls provide the highest level of batch productivity and efficiently.
Agitator Selection
Mepaco has engineered several types of agitator configurations. Ribbon style blenders provide a lower level of shear. Single or double agitators with paddles provide a more aggressive blend.
The desired system expectation is also a factor. Agitators can be designed to reduce product discharge waste; designs can also provide suspension to hold product until downstream equipment is ready.
The type of thermal heat solutions and type of food product will drive the need for scrapers. Indirect heating applications typically require scrapers to prevent burn-on during the heating process.
For more information about mixing and blending applications, check out our e-book on “Comparing Agitator Solutions.”
Intended Use
The agitator and controls package for the cooker have been specifically engineered for a particular set of batch parameters. It is critical that operators understand the expected performance of the cooker and blending settings.
After commissioning, when a change is made in the food product, temperature, or recipe alteration, it may affect agitator effectiveness and overall efficiency of the cooker. If any delays or inefficiencies are noticed, contact the factory to provide a system check, or provide system adjustments to the application changes.
Maintenance Strategy
It is vital to keep agitators well maintained. Flexed or stressed agitators do not perform efficiently, and in some cases, minor efficiencies turn into critical downtime scenarios when not maintained properly.
If plant personnel make a repair to an agitator, it is important to schedule an after-event service call to make sure the repairs hold up to stainless welding fortifications and proper straightening to prevent future issues.
Scraper systems may degrade over time. Check scraper assemblies during maintenance intervals, and replace scrapers that become ineffective. Worn scrapers are a liability to food safety and product quality that can cause a critical shut-down if scrapers crack or break up into the food product; or become ineffective due to excessive wear.
Agitators are one part of the overall solution for cooking and blending. Visit our web page to learn more about thermal processing equipment.
Many processors make their own repairs to equipment, but in the case of agitators, the repair must be sound to avoid problems in the future. Mepaco Service technicians are trained and experienced to troubleshoot shaft wear and are specialists in the repair of stainless steel. Here is a list of what not to do when making your own repairs:
If you need to make a repair to continue production, be sure to schedule after care for the agitator. You need an assessment to make sure the agitator is straight and that the welds will hold under stress. We are currently experiencing long lead times for replacement agitators, so whether it is an after-event service call or a scheduled audit, it is important to have the agitator checked out to maintain production up-time.
In some cases, there is a particular event that causes agitator damage such as a shovel or fork falling into a piece of processing equipment. However, there are several other signs that determine when an agitator is failing:
Here are some causes of agitator damage:
Agitators are part of Mixers, Mixer-Cookers, and ThermaBlend Cookers. This equipment is the most important part of the processing line and must be maintained for maximum uptime. Other equipment, such as Metering Screws with Hoppers have leveling ribbons that may also need to be included in the list for agitator maintenance.
Currently, there is a 3-to-6-month lead time for a new agitator. In some cases, agitator repairs can be made at the customer site. Mepaco Services may be able to use a sleeve or secure welds to get the machine back up and running. Sometimes, it is possible to make repairs for temporary production while the new agitator is put on order.
Contact Parts and Service at 920-356-9900 for more information.
Case Story: What can happen when an agitator problem is ignored?
A high-volume pet food processor utilized a Mixer/Cooker in their operations which produced 45-minute batches. The application called for 28 RPM and mixing cold product at 35 – 45 degrees. During the process of loading different ingredients into the Mixer-Cooker, a Vmag buggy fell into the mixer, causing damage to the agitator.
The processor made repairs to the bent shaft and paddles and was able to get the Mixer-Cooker back online into full production.
Many processors assume that if the paddles do not rub the side of the tub, that the agitator has had a successful repair. But in many cases (and in this case), there was extensive damage and over time the shaft began to flex, causing the agitator to break. This failure completely stopped production.
There are a few choices to stay ahead of agitator care:
Preventative Maintenance: Partner with Mepaco Services to inspect agitators to ensure the shaft is straight and look for stress and other damage.
After Event Care: Processors may be able to fix the shift to continue production, but contract with Mepaco Services to inspect the shaft and straighten if necessary.
Most importantly, processors should avoid emergency maintenance, causing down-time and lost production.
It is not uncommon to have dropped tools into Mixers, so prepare for the event if it does happen. Consider an audit to assess the life of the agitator and consider ordering a replacement so you can have duplicity for uninterrupted down-time.
Delivery of agitator replacements are 3 – 6 months out due to the availability of stainless material. Mixers, Blenders and Grinders are the work horse of the processing system, so be sure that agitator care and component availability are part of the maintenance program.
Mepaco Services offer on-site audits, training, and service contracts as well as emergency repair.
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