Fish meal and blood meal are two versions of the same problem: both are animal protein, both are heat sensitive, and both carry a lot of water and stickiness. Fish meal differs in its oil content, which brings two extra difficulties. First, a film of oil forms on the surface during drying and blocks vapour from moving out of the particle, so hot air alone struggles to get through. Second, that oil is combustible and the dust concentration is high, so the dust collection system has to be specified at the strictest explosion protection level. Our standard configuration is therefore a flash airflow line, with the residence time compressed to seconds so the vapour leaves before the oil seals the surface.
Fish meal and blood meal are two versions of the same problem: both are animal protein, both are heat sensitive, and both carry a lot of water and stickiness. Fish meal differs in its oil content, which brings two extra difficulties. First, a film of oil forms on the surface during drying and blocks vapour from moving out of the particle, so hot air alone struggles to get through. Second, that oil is combustible and the dust concentration is high, so the dust collection system has to be specified at the strictest explosion protection level. Our standard configuration is therefore a flash airflow line, with the residence time compressed to seconds so the vapour leaves before the oil seals the surface. Temperature is again controlled by the material temperature: protein denaturation is more damaging than oil oxidation, so protecting quality comes first. Where throughput is very large, or the oil content is high enough to need a longer residence time, a rotary drum becomes an option, but then oil building up on the drum wall has to be solved as well.