Horizontal double temperature zone I-131 destructive distillation device

Abstract

The invention discloses a horizontal double temperature zone I-131 destructive distillation device. The horizontal double temperature zone I-131 destructive distillation device comprises a heating furnace of a horizontal tubular furnace structure, a furnace cover, a distillation absorber, and a telescopic rack; the distillation absorber is arranged in a heating furnace chamber; the furnace cover,and the telescopic rack are arranged on a same end of the heating furnace; one end of the telescopic rack is horizontally fixedly arranged at the top center of the heating furnace, and the other end of the telescopic rack is designed to stretch downward vertically and is connected with the furnace cover on the heating furnace side through slide connection. The horizontal double temperature zone I-131 destructive distillation device is realizing rapid carrying and high efficiency capturing of high temperature molten piled TeO2 distillation high temperature I-131 steam; a low temperature zone isadopted for purifying treatment of distillation carrying gas, and it is beneficial for increasing of Na131I production efficiency and production safety.

Description

technical field [0001] The invention belongs to the technical field of radioisotope preparation, and in particular relates to a horizontal double temperature zone I-131 retort device. Background technique [0002] Na used in the production of radiopharmaceuticals 131 I raw material, mainly TeO irradiated by high temperature (about 750°C) dry distillation reactor 2 (Tellurium dioxide), prepared by absorbing the radioactive I-131 (iodine-131) vapor in the carrier gas (generally air) with dilute lye (generally NaOH solution with a concentration less than 0.5mol / L). The Institute of Nuclear Physics and Chemistry of the China Academy of Engineering Physics, as well as the domestic China Institute of Atomic Energy and China Nuclear Power Research Institute, have all worked in their Na 131 In the production process, the vacuum pump is used to pump air, and the high-temperature carrier gas in the distillation furnace is directly introduced into the bottom of the absorption bottle ...

AI Technical Summary

Problems solved by technology

However, due to the high temperature of the carrier gas, the volume of the absorption liquid added in the absorption bottle is small (generally no more than 20mL), and the heat brought by the high-temperature carrier gas can easily cause the temperature of the absorption liquid to rise rapidly and appear in the upper part of the absorption bottle. "Fog", and carried by the exhaust gas into the exhaust gas treatment device, resulting in low absorption efficiency of I-131 vapor in the carrier gas and evaporation loss of the iodine-131-containing absorption liquid, and also creates greater pressure on the on-line treatment of the exhaust gas and discharge up to the standard

Reducing the flow rate of the carrier gas is beneficial to reduce the evaporation of the absorption liquid caused by heat exchange, but it is not conducive to preventing the loss of iodine-131 vapor in the air duct due to temperature loss and being absorbed by the tube wall, and it is also not conducive to the timely loading of a large amount of iodine-131 in the distillation tube. Prolonged production (distillation or holding) time and a greater risk of iodine-131 vapor leaking from the feed port, especially when tellurium dioxide reaches its melting point

Due to the domestic retort reactor lighting TeO 2 Production of Na 131 The devices of I all use vacuum pump to pump air to maintain the directional flow of the carrier gas, and maintain a certain negative pressure in the distillation furnace cavity to prevent iodine-131 vapor from leaking, and in order to obtain products with higher radioactive concentrations, a small amount is added to the absorption bottle. The dilute lye, the iodine-131 yield of the prior art is often lower than 90%, and the risk of iodine-131 vapor leakage polluting the environment is higher

Moreover, the distillation tube and the absorber of the prior art are split, connected by a plastic tube or a rubber tube, and the strong gamma radiation and high temperature of the radioactive iodine-131 in the carrier gas have a greater impact on the service life of the connecting tube. It is prone to aging and cracking in the medium, resulting in the leakage of radioactive iodine-131 vapor, which shortens the service life of the production device and increases the risk of maintenance personnel receiving more radiation doses, which is not conducive to safe production

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