H4-VV-23-A ependable largely lowmaintenance and above all Helical gear Reduction Box H4

Flender/Flender Gear Units/Helical gear Reduction Box H4

gement. An essential requirement for the industrial use of food irradiation is an economical source of radiation energy that can deliver the treatment. To-day, electron accelerators and synthesized radioisotopes are the two types that satisfy thisrequirement. The systems have comparable efciency but differ in the constraints impliedin their use. These systems must be installed in shielded room to allow the treatment totake place without compromising the health of humans in the vicinity of the irradiator. Electron accelerators (Fig. are simpler to operate because they can be turned on and off easily. There are available at relatively low cost. The limitations of these ma- chines are related to the low penetrating power of accelerated electrons. This technologyis suitable only for processing of thin layers or surface treatment of food materials. Thehigh voltage of electron beams must be lower than or equal to 1 MeV in order to preventinduction of radioactivity in food materials being irradiated. The power of the machine Irradiation 6 Fig. 1 View of an electron accelerator. can vary from 5 to 2 kW. Accelerated electrons penetrate to depth of about 4 cm in water. There are many types of electron accelerators; the main differences among themare in the methods used for creating the high voltage required. From one side, hotlament emits electrons into an evacuated chamber. These electrons are attracted by high positive electric potential and are focused into narrow beam. The electron beam passes between the poles of an electron magnet with changing magnetic eld. The beamsweeps from side to side. Food products are usually loaded with conveyor to the irradia-tion room. It is very important to survey the energy level of accelerated electrons continu-ously and to ensure that it does not surpass the value that would render the food radioactive. 6 Lacroix et al. With synthesized radionuclides, gamma radiation is produced continuously at spe- cic energy level. Selected