TECHNOLOGIES & APPLICATIONS

PULSED ELECTRON-BEAM STERILIZER OF THERMOLABILE POWDERY AND LOOSE MATERIALS MAIN FIELDS OF APPLICATIONS

Main fields of applications:

sterilization of powdery crude drugs for pharmaceutical industry;
disinsection and disinfection of loose agricultural products (grain, seeds, etc);
sterilization of biologically active additives (BAAs).

Besides the above-listed products, sterilization of hermetically packed dressing and surface sterilization of medical instrument are possible as well.

Advantages of a nanosecond e-beam pulse-periodic high-current accelerator relative the heated-cathode continuously operating accelerators are as follows:

2-5 times reduced required total absorbed dose owing to high power of a dose in each pulse as well as possibility of flexible optimization of electron energy (in the limits of 150-300 keV) and pulse repetition rate against the preset rate of transporter feed, grain size or thickness of the powder layer under radiation allow decreasing the flux of bremsstrahlung radiation dangerous for service staff and reducing the dimensions of the setup jointly with the local-protection lead chamber;
zero energy consumption for cathode heating;
practically unlimited life time of a metal-dielectric cathode.

The sterilizer setup includes:

source of nanosecond electron beam - a field-emission high-current pulse-periodic accelerator;
vibrofeeder with a sterilizable material bin;
conveyor for transporting the sterilizable material into the radiation chamber;
radiation chamber with the lead-reinforced shielding walls;
PC-based system for remote accelerator-mode and conveyor-feed control with self-diagnostic elements.

The powder or grain in the form of a homogeneous mass is supplied from the bin to the conveyor by means of the vibrofeeder and transported with the e-beam into the radiation zone. The sterile product is collected in the receiver.

The Setup Parameters:
1.	Electron energy	150–300 keV
2.	Beam current	5-6 kA
3.	Pulse width	10 ns
4.	Pulse repetition rate	1–200 Hz
5.	Power consumption	3–5 kW from the standard 220/380-V mains
6.	Computer control
7.	Local biological shielding

Capability of the sterilizer may vary depending on the seeding of the initial product, requirements to sterility, and powder density and can reach 100-200 kg/hour.

Testing of the pilot setup performed in collaboration with the ICN Pharmaceutical Company (Tomsk) demonstrated that, whatever is the kind of the powder or loose material, the sterilization is achieved at the dose level of 5-10 Mrad. Absorption of the doses with each fragment of the drug occurred during the time of the order of 1 sec and the heating during the sterilization was not over 8-10 °C. No changes of physicochemical properties or taste qualities of the food raw material (for example pine nut meal) were revealed as well.

For further information please contact:

Alexeenko Pavel I.
Leading Constructor

Phone: (3822) 49-14-76
Fax: (3822) 49-24-10
E-mail: api@lfe.hcei.tsc.ru

Vladislav V. Rostov
Dr. Sci. (Phys. & Math.), Department Head

Phone: (3822) 49-16-41
Fax: (3822) 49-21-34
E-mail: rostov@lfe.hcei.tsc.ru

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