Drying and Cooling shrimp feed in One machine

Incorporation of the carousel dryer to shrimp feed pelleting lines

Even though the G1 technology is still a popular option in many Asian countries, there is a growing demand to increase the incorporation of sustainable plant-based protein while keeping water stability (Bae et al., 2020). One way to improve the water stability of a plant-based protein is by adding moisture to the mash. The benefits of increasing the moisture content during mash cooking are the increase of starch cooking and the lubricating effect of the mash when passing the pelleting hole.

Carousel dryer was first incorporated into the shrimp pelleting line back in 2013 in a large Indian shrimp feed manufacturing company. This started the second generation (G2) pelleting system. This dryer can fulfill all conditions needed to dry the shrimp feed properly and produce high-quality shrimp feed. Nowadays, the G2 system has become popular and utilized in many different pelleting lines in Asia.

The incorporation of the carousel dryer after the postconditioning process in the production line opens up the possibility of increasing the mash moisture before the pelleting process, due to the ability of the dryer to take out 4-5% of moisture content from the feed. The significant improvement of G2, when compared with the G1 in shrimp feed drying, are:

• Optimum drying moisture control. The carousel dryer can dry material with ±0.5% moisture variance, much less than the G1 (± 1%). Having adequate moisture control means the water content in pellets can be precisely controlled and indirectly reduce the loss of raw materials.
• The dryer optimally utilizes the drying air, thus minimizing energy use.
• The G2 technology can reduce steam usage for the post-conditioning system by up to 15%.

Latest drying and cooling technology for shrimp feed pellet

So what is the latest technology in drying and cooling shrimp feed? We considered all the requirements and the experience in the field and have developed a Generation 3 (G3) pelleting system that incorporates the dryer and cooler (TK-series) in one machine (Fig. 1). IDAH sold the TK-series machine to China and India back in 2021 (Fig. 2). The two benefits of this G3 system, when compared to G2 system, are:

• Total moisture control: easy and fast. The TK-series can produce feed with ±0.5% moisture variance in both dryer and cooler. This combination solved the high moisture variance problem that usually occurs when applying the conventional box cooler. This TK-series machine lessens the point to control in the production flow.
• Saving drying energy. In a carousel dryer, the counterflow drying airflow will support efficient heat transfer and give a low exhaust air temperature. The system utilizes the air exhaust from the cooler as makeup air for the dryer. The dust-free makeup air discharged from the cyclone (or jet filter) still contains some amount of heat and can lower the energy use (15- 30%) and reduce the amount of air emission (30-50%) and decrease odor problems.

Conclusion

In the past 40 years, there have been breakthroughs in shrimp feed production technology. Along with the changes in the formulation from animal-based to become plant-based, we also utilized new technologies to enable the production of high-quality shrimp feed. The main changes were, first, the moisture level increase during the pre-pelleting process, which improved the cooking process and water stability; second, the post-conditioning system prolonged the cooking of the pellets; and lastly, the incorporation of carousel dryers, which gave total moisture control (+/- 0.5%), energy-saving (15-30%), and lower dust/odor exhaust (30-50%) that benefited feed producers.