P. Hargittai

Experiences with a high capacity industrial scale pilot onion irradiator

Since 1969 experimental and pilot-scale radiation technological work has been regularly carried out in our Institute including the radiation treatment of food and agricultural products /i/. Our universal, K-120 type irradiation facility designed for experimental purposes /2/ can be applied for the regular testing of food irradiation technologies since the introduction of container irradiation technology. Among others the radiation processing of onion 20-30 t a year was carried out by this facility at a dose of 50 Gy /5 krd/. The irradiation was ordered by the Central Food Research Institute with the aim of proving for food storing companies and cooperatives the practical use and economic efficiency of radiation treatment when storing large amounts. These large-scale preliminary experiments as opposed to previous laboratory experiments on a few kg items were convincing and gave rise to demands for large scale /commercial/ irradiation so as to implement a more economic way of storing onion and reduce sprout losses. The series of large-scale storage experiments carried out for years was very successful. The storage loss decreased to 20-50% against the previous 80%, that is by 30-60% more product could be marketed in spring, at higher prices. Seeing the favourable results, the idea to carry out radiation treatment on the spot where onion is stored arose again /3/. To make the treatment economic we set as an aim to establish two types of irradiation facilities: i. transportable irradiator with a mean irradiation capacity of 5-10 t/h /4/; 2. on-site high capacity irradiator with a maximum capacity of 30-60 t/h. In the case of the first type we aimed at avoiding the difficulties met with such irradiators already built: to strive for a general purpose facility with the consequence of a bulky mass, low capacity and high price. It is well-known that in the heroic age of isotope application the USA, France