Setting method of nuclear level indicator for pressure vessel

Abstract

The invention discloses a method for setting a nuclear level indicator for a pressure vessel, which comprises the following steps of: 1) determining the mounting position of the nuclear level indicator on the pressure vessel according to an operation level in the pressure vessel; 2) according to the mounting position of the nuclear level indicator, determining the installation sequence of the nuclear level indicator as follows: a, the built-in nuclear source sleeve is installed; b, setting a nuclear emission source; c, surfacing the annular boss; d, a non-penetrating hole is machined; and e, installing a nuclear ray receiver. According to the method for setting the nuclear level gauge, the depth of the non-penetrating open pore can be greatly improved, so that the penetrability of rays of the nuclear level gauge is improved, the dosage of a nuclear source is reduced, and the economic cost and additional radiation risk of the nuclear level gauge are reduced.

Description

technical field [0001] The invention relates to the field of pressure vessels, in particular to a method for setting a nuclear level gauge for a pressure vessel. Background technique [0002] In petrochemical installations, when the internal environment of the pressure vessel is high temperature, high pressure or the material is highly viscous and corrosive, in order to measure the change of the material level inside the vessel, a nuclear level gauge measurement system with non-contact characteristics is usually used. Nuclear level gauges generally consist of a built-in nuclear source and an external receiver. [0003] When the pressure vessel is subjected to high temperature and high pressure, the shell wall thickness is relatively thick, approximately 100-400mm. When the nuclear level gauge is running, the ray passes through the thicker steel plate and will have greater attenuation. In order to reduce the attenuation of rays, reduce the dose of the emission source, ensur...

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Problems solved by technology

[0004] In order to ensure the bearing capacity and anti-fatigue and anti-creep performance of the non-penetrating opening, the engineering design usually adopts to reduce the opening depth to ensure that the shell at the opening has a large residual wall thickness, but in order to ensure a certain For penetrability, it is necessary to increase the dose of the emission source of the nuclear level gauge. This solution is not only economical, but also brings strong radiation safety risks.

Another solution is to weld the reinforced short pipe outside the opening, but there are the following problems: it is difficult to achieve full penetration connection between the short pipe and the outer wall of the cylinder, and it is difficult to achieve a close fit between the inner side of the welded pipe and the outer edge of the opening, so its The strengthening effect is limited, and the local peak stress on the outer edge of the opening is difficult to be relieved

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