Hydrogen analyzer for uranium dioxide fuel pellets

FIELD: analyzing metals for oxygen, nitrogen, and hydrogen content including analyses of uranium dioxide for total hydrogen content.

SUBSTANCE: proposed analyzer depending for its operation on high-temperature heating of analyzed specimens has high-temperature furnace for heating uranium dioxide pellets and molybdenum evaporator; molybdenum evaporator is provided with water-cooled lead-in wire, and molybdenum deflecting screen is inserted between molybdenum evaporator and furnace housing.

EFFECT: simplified design of electrode furnace, reduced power requirement.

1 cl, 1 dwg

 

The invention relates to high-temperature heating of samples and can be used for analysis of metals for oxygen, nitrogen and hydrogen, in particular for the determination of total hydrogen pellets of uranium dioxide.

Known analyzer hydrogen firm LEKO RH-404, equipped with a high-temperature oven EF-400 power 6,5 kW, also known domestic analyzer AV-7801 NGOs “Chermetavtomatika” - Moscow, having the same electrode pulse furnace resistance.

The hydrogen analyzer consists of a graphite crucible, in which at a temperature of 1800°C in an atmosphere of inert gas is hydrogen gas, which is then measured in cell thermal conductivity. The signal from the detector is processed by computer.

A disadvantage of the known electrode pulse furnaces of the resistance is that heating of the sample used a graphite crucible, which is placed in a sample weighing less than 1 gram.

A small amount of analyte may not always provide objective information, in addition, graphite at high temperature starts to evaporate, polluting gas path. Causes difficulty itself furnace design, which does not allow simultaneous loading of 5-6 tablets in the reactor.

The closest to the technical essence and the achieved is the result of (prototype) is the analyzer of hydrogen in the fuel pellets of uranium dioxide by the RF patent №2151434, IPC G 21 17/06, 1999

In the prototype heating element made in the form of a cylinder of graphite, inside of which is placed molybdenum evaporator. Heating of the pellets is carried out by heat transfer from the electrode graphite furnace through the walls of molybdenum evaporator.

The disadvantage of this construction of the electrode furnace analyzer hydrogen is an inefficient use of electricity by heating the tablets in the evaporator.

The objective of the invention is to simplify the design of the electrode furnace, reducing the power consumption of the current.

The problem is solved due to the fact that the analyzer hydrogen containing high-temperature furnace for heating pellets of uranium dioxide and molybdenum evaporator, according to the formula of the invention molybdenum evaporator equipped with waadookodaading the tokovodov, and between molybdenum evaporator and the furnace body is molybdenum reflecting screen.

This set of features is new and involves an inventive step, since the heating element is directly molybdenum evaporator, the ends of which are summed up two tocobaga made in the form of rings, providing a reliable contact with the molybdenum evaporator. The hydrogen analyzer equipped with a molybdenum reflective screen to create a uniform rate the temperature field around the molybdenum evaporator, and also to increase considered horizontally isothermal surface of the working area. The furnace housing is water-cooled.

The drawing shows a diagram of the analyzer of hydrogen.

The hydrogen analyzer consists of molybdenum evaporator 1, a water-cooled tokovodov 2, water-cooled casing 3, molybdenum reflective screen 4, stock delivery to the evaporator fuel pellets 5.

The hydrogen analyzer works as follows.

Using stem 5 fuel pellets of uranium dioxide is placed in a molybdenum evaporator 1, which is connected with the power source. On vodoohlazhdaemogo the tokovodov 2 serves voltage from 0 to 18 Century Molybdenum reflective screen 4 creates a uniform temperature field around the molybdenum evaporator. The voltage varies according to the program by the microprocessor. The rate of heating molybdenum evaporator 300°in a minute. If necessary, the heating rate may be changed or transferred in burst mode. For reliable electrical contact and avoid burning the surface of the current-carrying graphite molybdenum electrodes to the evaporator on the surface between them put a graphite paste. Tablets are heated to a temperature of 1800°in the helium atmosphere, highlighted the analyzed gas stream of helium is delivered to the detector of the analyzer. Electrical circuits is to heat the molybdenum evaporator provides the necessary temperature and allows you to adjust power and to reach the required temperature of the analyzed pellets of uranium dioxide. The presence vodoohlazhdaemogo case 3 allows to reach the optimal temperature inside molybdenum evaporator.

The use of the proposed invention reduces the power consumption and simplifies the design of the electrode oven.

The analyzer hydrogen containing high-temperature furnace for heating pellets of uranium dioxide, molybdenum evaporator, characterized in that the molybdenum evaporator equipped with a water cooled tokovodov, and between molybdenum evaporator and the furnace body is molybdenum reflecting screen.



 

Same patents:

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