Carousel dryer/cooler from CPM's IDAH offers sustainability in petfood industry

The carousel working principle

 

In the carousel dryer, the product enters through a rotary valve onto the revolving trays. The Carousel system ensures a first in, first out (FIFO) principle, after nearly one revolution, the product is gently discharged and mixed into the next lower tray. This process is repeated until the product drops from the last tray into the outlet where a rotary valve prevents air leakage. The revolution means that the product undergoes the same treatment all along the decks, ensuring that the product comes out in uniform moisture. Furthermore, the multiple tumbling action gives an efficient heat exchange with the air, resulting in a low dryer exhaust air temperature.

 

Integrating dryer and cooler as one solution

 

The Carousel technology is a unique solution for both energy efficiency and precise moisture control. Optimal moisture control is made easy by using carousel technology in both the dryer and cooler. Additionally, the exhaust air from the cooler can be directed as make-up air for the drying process. Therefore, an integration of the dryer and cooler into one compact machine with a FIFO discharge principle like the carousel dryer will give an outstanding moisture control performance.

Ambient air cools the product and after filtered and heated it is used as drying air for the upper section. This carousel model offers many benefits and features when compared to traditional equipment.

 

Improving product moisture control

 

Managing the temperature and moisture content of the finished product is the main task for the drying and cooling process. However, when the feed is overdried, it causes material loss, as well as extra energy consumption. When the feed is too wet, the product will have a higher risk of quality degradation and mold growth.

 

Due to its unique working principle, all the products in this carousel dryer will get the same heat treatment and retention time. This is combined with a unique and easy control system, along with real-time monitoring and modification of the drying parameters. The carousel dryer will give a uniform and constant moisture level that makes it easier to achieve the target average moisture, which will save energy and raw materials.

 

Improving energy efficiency

 

The drying and cooling process accounts for a significant part of the overall energy consumption. Rising energy costs and sustainability awareness regarding energy consumption have driven feed manufacturers to request further support to improve their drying and cooling functions. To maximize energy efficiency, we have to look into:

• Maximizing the use of warm product energy.
• Minimizing the amount of water evaporation.
• Minimizing energy loss with the exhaust air.

 

By using the cooling air as makeup air into the dryer, the heat energy can be reused. Also, efficient heat exchange lowers the amount of exhaust air. Low exhaust air volumes will reduce the cost needed for odor treatment.

 

Reducing the space required

 

While upgrading the production capacity of a feed mill or improving the production process, the introduction of new equipment into the facility is required and space limitations may arise. The carousel dryer is already more compact than a typical dryer.

 

Potential savings

 

A direct result of using cooling air as makeup air for the dryer is savings. If you assume that the temperature differential between the ambient and cooler exhaust air is 25°C, you save up to 30 kg/t steam. At the same time, you will reduce the amount of exhaust air by 50%, reducing odor treatment costs significantly.

Getting better moisture control, for example 0.5%, is saving not only about 10 kg/t steam consumption in the dryer but, even more importantly, saving 0.5% raw materials cost and having a 0.5% higher output capacity.

 

For more information, contact [email protected].

 

Source: CPM IDAH