RU152349U1 - SURFACE ANALYZER ANALYZER - Google Patents

Abstract

на 1 Вт мощности рентгеновской трубки, где I₀ - интенсивность излучения рентгеновской трубки, I₁ - интенсивность излучения, прошедшего через фильтр; фильтр может быть выполнен из нескольких слоев фольги. Снижаются потери интенсивности излучения при его поступлении от рентгеновской трубки на детектор и, соответственно, снижается время экспозиции и увеличивается скважность измерений. The utility model relates to means for measuring the sulfur content in hydrocarbon liquids based on the absorption of x-ray radiation by a substance, namely, to x-ray absorption analyzers of sulfur in oil and oil products and can be used directly in process pipelines in the stream. In the in-line sulfur analyzer containing an X-ray tube, a measuring cell and an X-ray detector, a filter made of foil is installed between the X-ray tube and the measuring cell, the material of which is selected from metals with atomic numbers 42 to 49, and the minimum filter thickness b _min is not less than 50 microns, and the maximum thickness b _{max of the} filter is determined from the condition

per 1 W of power of the X-ray tube, where I ₀ is the radiation intensity of the X-ray tube, I ₁ is the intensity of the radiation transmitted through the filter; the filter can be made of several layers of foil. The loss of radiation intensity is reduced when it arrives from the x-ray tube to the detector and, accordingly, the exposure time is reduced and the duty cycle of the measurements increases.

Description

The utility model relates to means for measuring the sulfur content in hydrocarbon liquids based on the absorption of x-ray radiation by a substance, namely, to x-ray absorption analyzers of sulfur in oil and oil products and can be used directly in process pipelines in the stream.

Ionizing radiation is absorbed by both sulfur and oil hydrocarbons (oil products), in which the ratio of carbon to hydrogen C / H can vary widely. The absorption capacity of carbon and hydrogen are different, which is why not only the desired sulfur content, but also the C / H ratio will affect the absorption of radiation in oil (petroleum products). As a result, the uncontrolled composition of the hydrocarbon matrix — the C / H ratio, which is constantly changing — will affect the measurement error of sulfur content.

It is known that at an ionizing radiation energy close to 22.8 keV, the mass absorption coefficient μ in the hydrocarbon matrix is practically independent of the C / H ratio.

Known x-ray absorption analyzer of sulfur in oil and liquid petroleum products, including a radiation source - a radioactive isotope - cadmium-109, a measuring cell, a proportional x-ray counter, a detection unit, an amplitude discriminator, as well as a power supply unit, SU 16898117 A1, publ. 11/07/1991. The emission spectrum of this source contains a line with an energy of E = 22.3 keV.

The disadvantages of this technical solution, as well as other devices in which radioactive isotopes are used as a radiation source, are:

- the need to use special tools and compliance with established standards for the transportation, storage and use of radioactive substances;

- relatively low radiation intensity of the radioactive isotope, which reduces the duty cycle of measurements, since it is necessary to increase the exposure time for a set of statistical data, since the measurement of sulfur concentration is performed on the stream; a large exposure time leads to a loss of measurement reliability;

- the need to take into account a constant decrease in the activity of a radionuclide source due to its decay;

Known in-line sulfur analyzer containing an x-ray tube, measuring cell, x-ray detector, between the x-ray tube and the measuring cell placed in series, one after the other, two targets. In front of the measuring cell and in front of the detector, collimators are installed that form parallel radiation beams. Antimony was used as the first target, and silver was used as the second target. X-ray tube radiation is scattered on the first target and excites antimony fluorescence with an energy of 26 keV. This radiation hits the second target and excites the fluorescence of silver with an energy of 22 keV, RU 53017 U1, publ. 04/27/2006.

The disadvantage of this technical solution is the very large loss of radiation intensity on the targets, 1000 or more times on each target, as a result of re-radiation. In addition, a substantial part of the radiation is lost at the collimators. As a result of losses in radiation intensity, an increase in exposure time is required, which leads to a decrease in the duty cycle of measurements and, ultimately, to a loss in the reliability of the results.

Known in-line sulfur analyzer containing an x-ray tube, a measuring cell and an x-ray detector; between the x-ray tube and the measuring cell placed a target made of two materials - silver and an element with atomic numbers from 42 to 57; before the measuring cell and the detector are collimators, RU 2367933 C1, publ. 09/20/2009.

This technical solution was made as a prototype of this utility model.

The indicated device has the same drawbacks as the in-line analyzer according to RU 53017 - significant radiation losses on the target (1000 times or more), as well as on two collimators. In general, the radiation intensity is reduced by no less than 5000-10000 times. As a result, there is a significant decrease in the measurement duty cycle due to an increase in the exposure time and, accordingly, a loss in the reliability of the measurements.

The objective of this utility model is to reduce the loss of radiation intensity upon its arrival from the X-ray tube to the detector and, accordingly, to reduce the exposure time and increase the measurement duty cycle.

на 1 Вт мощности рентгеновской трубки, гдеAccording to a utility model, in a flow sulfur analyzer containing an X-ray tube, a measuring cell and an X-ray detector, a filter made of a foil is installed between the X-ray tube and the measuring cell, the material of which is selected from metals with atomic numbers 42 to 49, with a minimum thickness b _the filter _min is at least 50 μm, and the maximum thickness b _{max of the} filter is determined from the condition

at 1 W of power of an x-ray tube, where

I ₀ - the radiation intensity of the x-ray tube,

Ι ₁ is the intensity of the radiation transmitted through the filter;

the filter can be made of several layers of foil.

The applicant has not identified any technical solutions identical to the claimed one, which allows us to conclude that the utility model meets the patentability condition “Novelty”.

The sulfur flow analyzer comprises an X-ray tube 1, a measuring cell 2, and an X-ray detector 3. Between the x-ray tube 1 and the measuring cell 2 in the housing 4 is installed a filter 5 made of foil. The foil material is selected from metals with atomic numbers 42 to 49, since:

- the energy of the characteristic lines of the K-series and K-absorption edges of these elements is close to the required range of 22-24 keV;

- these metals are chemically passive in the atmosphere;

- obtaining thin foil from these metals is technologically available. When using metals with atomic numbers less than 42 and greater than 49, the energy of the characteristic lines of the K-series and K-absorption edges goes beyond the required range of 22-24 keV.

The minimum thickness b _{min of the} filter must be at least 50 μm, otherwise a satisfactory spectral composition of the radiation transmitted through the filter is not ensured.

на 1 Вт мощности рентгеновской трубки, гдеThe maximum thickness b _{max of the} filter is determined from the condition

at 1 W of power of an x-ray tube, where

I ₀ - the radiation intensity of the x-ray tube,

Ι ₁ is the intensity of the radiation transmitted through the filter.

, что достаточно для достижения требуемой скважности измерений. При этом b_max составит 1200-1600 мкм.The use of powerful x-ray tubes (the highest power of modern tubes reaches 5 kW) allows you to increase the thickness of the filter. However, the use of such powerful x-ray tubes in a in-line sulfur analyzer is completely impractical, since in this case a special water cooling system, a biological protection system from powerful radiation, a complex control system, etc. For a flow analyzer, it is advisable to use x-ray tubes with a power of no more than 3-5 watts. In this case, the maximum thickness b _{max of the} filter should provide a value of I ₁ at which

that is enough to achieve the required measurement duty cycle. In this case, b _max will be 1200-1600 microns.

In a specific example, an X-ray tube of type 1 BH-7 manufactured by Svetlana OJSC, St. Petersburg, Russia with a silver anode, and a X-ray scintillation detector 3 were used. The filter 5 can be made of several layers of foil, which allows you to form the spectral composition of the filtered by radiation so that the width of the spectral distribution is minimal (pseudomonochromatization) and its effective energy is as close as possible to the value of interest - 22.8 keV, while maintaining an acceptable intensity radiation detected by the detector at a given x-ray tube power.

The device operates as follows.

The characteristic and bremsstrahlung occurring at the anode of the X-ray tube 1 passes through the filter 5, the layer of oil (oil product) in the cell 2 and is registered by the X-ray detector 3. The filter 5 forms the spectral composition of the radiation I ₀ coming from the X-ray tube 1, so that the effective energy of the radiation transmitted through it is close to 22.8 keV. Such "pseudo-monochromatization" is necessary to eliminate the effect of a variable ratio C / H of petroleum hydrocarbons (oil products). The absorption of pseudo-monochromatized radiation will depend mainly only on the sulfur content in oil, the main absorbing component. The intensity I _{2 of the} radiation transmitted through the cuvette 2 registered with the aid of detector 3 allows us to calculate the sulfur content by the formula :.

,

,

where C _S is the sulfur content in the analyzed product;

ρ is the density of the sample, g / cm ³ ;

K ₁ , K ₂ - calibration factors, the value of which is determined from calibration measurements using standard samples with known sulfur content;

Ι ₁ is the intensity of the radiation transmitted through the filter;

I ₂ - the intensity of the radiation transmitted through the cell;

I _f - the intensity of the background radiation.

The implementation of the distinguishing features of the utility model provides a technical result consisting in a significant reduction in radiation intensity losses when it is received from an X-ray tube to an X-ray detector. This allows you to significantly reduce the exposure time, respectively, to increase the duty cycle of the measurements and the reliability of their results.

Prototypes of the device were manufactured and tested at OOO SPECTRON Scientific and Production Association, St. Petersburg, Russia, which, according to the applicant, allows us to conclude that the claimed technical solution meets the patentability condition “Industrial Applicability”.

Claims (2)

1. In-line sulfur analyzer containing an X-ray tube, a measuring cell and an X-ray detector, characterized in that a filter made of foil is installed between the X-ray tube and the measuring cell, the material of which is selected from metals with atomic numbers 42 to 49, while the minimum the thickness b _{min of the} filter is at least 50 μm, and the maximum thickness b _{max of the} filter is determined from the condition $$\frac{I_0}{I_{\mathrm{one}}}<200$$

per 1 W of power of the X-ray tube, where Ι ₀ is the radiation intensity of the X-ray tube, Ι ₁ is the intensity of the radiation transmitted through the filter. 2. The in-line sulfur analyzer according to claim 1, characterized in that the filter is made of several layers of foil.

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