DE2049500A1 - Device for determining the element concentration in hydrocarbon compounds - Google Patents

Description

PotentoftwoHe η η ι f \ π

Dr, Ing.H. Negendank 2 U 4 U 0

Dipl. Ing. H. Haudc Dipl. Phys. W. Schmitz

8 Münch fin 15, MoeoHst: .23

Yokogawa Electric Works Ltd. id.

j 32, 9, 2 -chome

| Musashino City October 8, 1970

j Tokyo, Japan Legal File: M-lj55O

: Device for determining the element concentration

in hydrocarbon compounds

The invention relates to a device for determining the concentration of sulfur or some other element, for example

j Chlorine, nickel or lead in hydrocarbon compounds such as

^ Crude oil or refined petroleum products by determining their abisorption of radioactive rays.

| Because the sulfur present in crude oil is dangerous for the general public conjured up, the control of sulfur concentration has recently received a great deal of public attention been. When determining the sulfur concentration in hydrocarbon compounds, especially in crude oil, heavy oil, Light oil and other refined petroleum products with the help of radioactive rays emitted by a target

> ι

The main sources of measurement errors are the change in the concentration ratio of carbon and hydrogen in the carbon and substance compounds and the change in the density of the hydrocarbons

connections viewed. The change in the concentration ratio can essentially be eliminated by suitable selection of the radioactive source and target , while the

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j the latter change through suitable further processing of a ι the signal representing the sulfur concentration and one for the Density of hydrocarbon compounds representative signal

can be compensated.

When the concentration of sulfur in hydrocarbon compounds I
j is to be determined in-by the intensity of a sample

j the hydrocarbon compound passing radioactive

Radiation is measured, the following equation (1) applies:

/ UH + R / U ™ / UH + R Is = Io exp { (/ ^u _s L / C H ¹

1 + R

1 + R

wherein
and

R = C _p / C _H

Kj Π

c _s + c _h + c _c = i

(2) D)

In the above equation (1), Is represents the electrical output of the measuring device caused by the radiation which has passed through the sample, Io represents the output of the measuring device caused by the radioactive radiation before passage, Ai is the mass absorption coefficient of sulfur, / u ... is the mass absorption coefficient of

/ ti

Hydrogen and ai " is the mass absorption coefficient of carbon, Cq is the concentration of sulfur, C _{11 is} the concentration

ο Xl

of hydrogen, C _c is the concentration of carbon, f is the density of the sample, t is the effective length of the sample, and R is the ratio of the concentrations of carbon and hydrogen. In the equation (1), the output Is is a puncture of the sizes C ₁ and R if it is possible to make the density f constant; the values of / U _g , Ai ^, ax _c and t are constant. In other words, the output signal Is changes with the concentration

- J - 109817/1864

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tration C ₀ of sulfur and is determined by the ratio C ^ / C ™ ^

ο L / JtI De-

influences. Should the output signal Is not due to the ratio R. are influenced, it is clear for this reason that the conditions / U "^ λλ_ and / u_" / U "should be metV and that it is necessary that the radioactive radiation fulfills the condition / U „= / U-. It is a sulfur analyzer

241
It has been proposed to use Am as a radioactive source for the radiation and silver as a target material to generate fluorescent X-rays with an energy of 22.162 KeV, which is characteristic of silver.

In this device, however, it is extremely difficult to determine the ratio of the concentrations of carbon and hydrogen to completely eliminate the error effect caused, so that it was impossible to achieve high measurement accuracy. With older ones Electrical measuring devices were used to compensate for the influence of the density of the sample after linearizing the sulfur concentration signal divides the signal by a density signal by means of a logarithmic amplifier. The logarithmic amplifier is not only complicated and expensive, but it also sets a design for great accuracies extraordinary Difficulties.

It is therefore the object of the invention to provide a device for determining to create the concentration of sulfur or any other element contained in hydrocarbon compounds, in which the influence of the ratio of the concentrations of carbon and hydrogen on the accuracy of the measurement in

- h - 109817 / 186A

is reduced to a large extent.

Another purpose of the invention is to provide a device for a

! to provide constant measurement of the sulfur concentration in which

Changes in the density of the sample are automatically compensated, without the need to use an expensive logarithmic amplifier.

Furthermore, a novel device for determining the concentration which uses radioactive radiation to pass through the sample, which works flawlessly, easily can be assembled and disassembled, has consistent operating characteristics and is radiated from the source Radiation used extremely effectively for determining the concentration.

Furthermore, the device should be used to determine the sulfur concentration or the concentration of other elements contained in hydrocarbon compounds so that the to measuring sample does not linger in a measuring tank, rather a steady flow of the sample substance through the measuring tank is ensured ' is.

According to the invention, the device for determining the concentration of a in a hydrocarbon compound or in • an element contained in a mixture of compounds, in particular one ; Elements with a mass absorption coefficient greater than

^! that of carbon and hydrogen (e.g. sulfur) by

- 5 - 10981 11 186A

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that they are a radiation emitting radioactive source with an I.
jEnergy level from 60 to 100 KeV, one with the radioactive radiation

Treatment of irradiated target for the emission of fluorescent IR-X-rays with an energy level of 23 to 24.5 KeV and

j a detector for the by the hydrocarbon compound ! has penetrated fluorescence X-rays.

In an expedient embodiment of the invention, the target is a composite body made from a combination of two metals which have been selected from the group consisting of silver, tin, indium and cadmium.

In another embodiment of the invention, the target is made from a single metal selected from the group consisting of indium and cadmium.

The invention also relates to a concentration measuring switch

ι *

: with a concentration detector for determining the concentration of an element contained in a hydrocarbon compound, with an amplifier for amplifying the concentration signal ^; from the detector, with a linearizing circuit for linearizing the output signal of the amplifier, a dividing circuit for

Dividing the output signal from the Linearisierkreis by \ a back related to the density signal of the hydrocarbon compound signal, having switching means for converting the density signal into a Exponentialsignai, which is a function of the density and a comparative concentration of the element / and means! For differentially adding the Exponentialssignals to a

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j Signal related to the concentration signal.

The invention will become more apparent from the detailed description that follows, which is accompanied by some drawings are. From the figures show:

! Fig. 1 is a schematic representation of the measuring device according to : Invention,

j FIG. 2 is a plan view of an embodiment of an inventive device trained targets,

3 shows a section through a target and a radioactive source for radiation,

Fig. 4 is a family of curves to illustrate the dependency of Display in percent by weight of sulfur for different target types of the ratio of the concentrations of Carbon and hydrogen,

Fig. 5 is a block diagram of a measuring circuit used in the invention;

6-10 are graphs showing the relationship between the sulfur concentration and the input-output ratio a dividing circle, where the density has been used as a parameter,

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Pig. 11 is a block diagram of a modified embodiment of FIG Invention,

12 is a partial circuit diagram of another embodiment of the measuring circuit,

Pig. 13 shows a section through a generator for generating a Concentration signal according to the invention,

Pig. 14 shows a cross section through the concentration signal generator according to FIG. IJ along the line XIV-XIV,

FIG. 15 is an enlarged sectional view of that shown in FIG. 14 Diffuser 56,

! F.

16 shows an enlarged perspective illustration of the diffuser »

17 shows a cross section through a source of radioactive radiation, as in the concentration signal generator shown in FIG is used,

18 shows a cross section through the source shown in FIG. 17 and FIG

19 shows the flow of liquid through a measuring tank in which; a diffuser is arranged.

The measuring device of the invention shown schematically in FIG. 1

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has a source 1 of primary radioactive or X-ray radiation with an energy level of 60 to 100 KeV, for example

241
can consist of Am. The primary radioactive radiation from the source 1 falls on a metal target 2 _; to generate fluorescent X-rays characteristic of the target material. The fluorescence x-ray radiation passes through the sample liquid to be examined, which flows through a tube 4a through a measuring tank 3; the X-ray radiation that has passed through is detected by means of a detector 5, which can be an ionization chamber, for example. The output current of the detector 5 is amplified in an amplifier and then fed to a display and / or recorder measuring device or an adjustment device after it has been previously combined with a density signal in order to compensate for differences in the density of the sample, as will be described further below .

According to FIG. 2, the target 2 has one made of different metals composite body on; in this example it consists of alternating sectors of silver (hatched sections) and tin. According to Fig. 3 »the one embodiment for represents a radioactive source 1 and a target 2, the target 2 is generally cup-shaped, with the center the bottom is slightly arched to form curved reflective surfaces; the source 1 is arranged over the center of the target.

For example, if the radioactive primary radiation comes from a source

241
falls on the target from Am, it radiates because of the

- 9 109817/1 86 Λ

photoelectric effect from fluorescence X-rays. The: energy of fluorescence x-ray radiation is due to the particular Material from which the target is made. The following Table 1 shows the specific energies of the fluorescence X-rays for various typical elements.

metal Ru Specific energy (KeV) Pd 17,478 ι molybdenum Mo Ag 19.278 'Ruthenium CD 21.175 palladium In 22,162 silver Sn 23.172 cadmium 24.207 Indium 25.270 tin

The fluorescence X-ray radiation emitted by the target 2 is obtained from the sample 4 in the measuring tank 3 (see FIG. 1) according to the equation

(1) absorbed, and the fluorescence X-ray radiation that has passed through the sample is detected by the detector 5 to produce an electrical output signal corresponding to the equation (1). The output signal is amplified in an amplifier and further processed in a suitable manner.

. The curves shown in Figure 4 were using a: obtained experimental arrangement shown in Figures 1 to 3 similar ISTJ the curves show the relationships between the listed values and the changing ^encryption: ratio of the concentrations of carbon and Hydrogen for j different target materials, where the concentration of the - 10-:

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Sulfur was kept constant. The initial values were calculated in units of the concentration of sulfur (percentages by weight)

calculates. The measuring tank used in the experiment was made of Bakelite and had a wall thickness of 6 mm. The effective length of the liquid was 30 mm and the areal density of the liquid (Was 1.975 g / cm. A mixture of cyclohexane and Tolaol was used and the ratio of the components was changed, '' to load different mixtures of liquid hydrocarbons

juxtaposed, which had different concentration ratios of carbon and hydrogen.

In FIG. 4, the curve marked Ag + Mo shows the characteristic features of a composite target which of silver «and molybdenum sectors with an area ratio of 50:50 is built up. The curves marked with Pd, Ag, Cd, In and Sn relate to targets made of palladium, silver, cadmium, Indium and tin, while the curve labeled Ag + Sn shows the characteristic of a composite target made of silver and Tin sectors with an area ratio of 50:50 is built up.

As can be clearly seen from FIG. 4, in the cases of the targets made of Cd, Ag + Sn and In, the deviations are Display values less than $ 0.01, while in the other cases deviations greater than $ 0.02. Especially in the case of the target composed of silver and tin the deviation of the display values less than $ 0.005. While in the exemplary embodiment described, the area ratio of

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20A950Q

Silver to tin is 50:50, the area ratio of 25: 75 to 75:25 if the allowable range of deviations is allowed expanded to less than - $ 0.01. It can therefore be concluded from Table 1 and FIG. 4 that the target is fluorescent X-ray radiation must emit in the energy range from 23 to 24.5 KeV in order to keep the permissible error in the range of - 0.01 $ Bring (in percent by weight sulfur).

According to FIG. 5, when a target composed of silver and tin is used, the body is made of tin, and 45 ° line sectors Ag of silver foil at 45 ° intervals (FIG. 2) are glued to the inner surface of the cup-like body. On the other hand, a target with silver and tin layers arranged one above the other can also be used, in which a thin film (10 to 100 αχ thick) of silver or tin is applied to a carrier made of tin or silver by means of suitable processes such as electroplating, vacuum vapor deposition, spraying will. If the thickness of the film is of a suitable value, the desired energy of the fluorescent X-ray emanating from the film can be obtained.

Since the values of the radiation efficiency are almost the same for silver and tin, the energy of the fluorescent X-ray radiation is per unit area of the target composed of silver and tin essentially equal to the corresponding energies of silver and tin multiplied by the corresponding areas of silver and tin divided by the total area of Silver and tin when the silver and tin layers are thick and

- 12 10981 11 186Z,

20495

have different surfaces; the energy is approximately equal to 2j5.7 KeV when the ratio of silver to tin is 50:50 i is; while in the case of a complete covering of the carrier made of one metal by a thin layer of the other metal

j the energy is determined by the thickness of the thin layer.

'In the case of the above-described combination of silver and tin

i set targets can have a sufficiently high sensitivity of the

Measurement can be achieved because the mass absorption coefficient / U _g j of the sulfur is greater than the composite mass absorption

I ption coefficient of carbon and hydrogen m „+ R / U ^ / l + R, 1 / π / ο

by a factor of 10 or a factor greater than 10.

! Although in the embodiment shown the measuring range of

Zero to $ 5 (in weight percent sulfur) and the density measurement range ranges from 0.8 to 1.0 g / cnr, it is necessary to use the area ratio of silver to tin in the target a suitable mask or a similar device to change to an extended measuring range of the concentration measurement or to achieve density.

As can be easily read from Fig. 4, show from one

! single metal (cadmium or indium) manufactured targets identification

: lines that coincide with the characteristic of the silver and tin set targets (see also Table 1) are obvious. Suitable! Combinations of cadmium and tin, cadmium and indium and indium

j and silver can also be used to build composite targets! that lead to similar energy levels as the ^hua

1 0 9 8 1 7/1 8 6 U

BATH ORIGINAL

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- -LJ? -

Silver and tin composite target. Since there is a target From a single material it is impossible to change the energy level, composite targets are preferable because it is at by changing the ratio of the metal components, it is possible for them to shift the energy levels within a certain range.

Although an ionization chamber has been used as a detector in the embodiment described above, this can be through a other suitable detector such as a scintillation counter. When compared with a scintillation counter shows ; that the ionization chamber is advantageous in that it j is not only possible to avoid errors due to miscounts, but that by increasing the intensity of the radioactive source also increases the sensitivity of the measuring arrangement can be. In addition, the accuracy of the measurement j

,

, because temperature fluctuations are easily compensated for and because the adverse effects of vibrations can be avoided.

According to the invention, therefore, X-ray fluorescence rays from a .Energy at which the absorption coefficients of carbon and

Hydrogen, generated by one made of silver and tin,

together ι tin and indium, cadmium and indium or cadmium and tin · set target or a target of only cadmium or indium loading] uses is. This creates a device for the very precise determination of the concentration of sulfur in hydrocarbon compounds, which cannot be determined by the

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2Q495QQ

Ratio of the concentrations of carbon and hydrogen is influenced.

at

Although / the embodiment described above, the concentration of sulfur has been measured, it should be noted that the device according to the invention can also be used to determine the concentration other elements can be used which have a larger mass absorption coefficient than hydrogen and Have carbon, such as chlorine, nickel, or lead.

The Pig. 5 shows a block diagram of a measuring circuit as shown in FIG of the invention is used. The measuring circuit has a detector 7 for determining the concentration of sulfur and closes

pill

a radioactive source 8 (e.g. Am), a cup-shaped one composite target 9 made of silver and tin, a measuring tank 10 and an ionization chamber 11 a. The measuring circle points furthermore an amplifier 12 with a high input resistance for amplifying the output current of the ionization chamber 11, and is provided with a feedback resistor 15 and a DC voltage source 14 provided for the ionization chamber, one terminal of the DC voltage source via an output terminal of amplifier 12 is grounded. Furthermore, a density detector 15 is provided, which is connected to the sulfur concentration detector by means of a line 16 is connected in series, the detector 7 being a known density detector of the vibration type. Of the j detector 15 has a resistor for measuring the temperature of the sample to correct the density signal in accordance with the reference temperature. Is in the same catfish

- PY 1098 1 7/1864

the measuring tank 10 with a resistor 18 -: for measuring the temperature; of the sample at the time when the sulfur concentration is measured in order to correct the density signal according to the temperature prevailing in the concentration measuring tank. The temperature measuring resistor 18 is placed in a branch of a bridge circuit, which generates a compensated density signal at its output terminals 20, which is the difference in the density of the sample at the temperature in the measuring tank and a correction factor for correcting the measured density with respect to the density at the reference temperature E in density signal converter 21 is connected as shown in Fig. 5 to convert the output signal (a frequency signal) of density detector 15 into a density signal considering the comparison density and into a density signal at the temperature of the concentration measuring tank and to convert the density signal into a DC voltage signal e ^, to be converted (e.g. into a DC voltage of 0 - 10 mV for <f = 0.8 - 1.0 g / cm). The correction of the density to the temperature at which the sulfur concentration is determined can take place outside the converter 21. For example, a correction signal can be applied to the output of converter 21. A voltage / current converter 22 is connected to the output of the converter 21 and is provided with a function conversion circuit to convert the output signal ej ., Of the density converter 21 into a current or voltage signal with a higher level (e.g. a direct current of 10-50 mA or a DC voltage from 1 to 5V), proportional to the output signal ef, and to be converted into a DC voltage signal e P ^ (e.g. 1 - 5V), where the DC voltage: signal e ^, the form of an exponential function of the density and the! Sulfur concentration (concentration at the Reference temperature)

1 Π 9 8 1 7/1 8 G h

-lo in the same way as the sensed sulfur concentration signal. A potentiometer 23 is across the output of the voltage-to-current converter 22 in order to generate a density correction signal from the exponential voltage signal e9 3. The output signal

of the potentiometer 23 is fed to a potentiometer 24 to I.

j set the reference concentration and the reference density of the sulfur!
j len, the potentiometer 24 being connected to a DC voltage source 25. Between the input terminal of the amplifier

12 and the connection point between potentiometer 24 and the DC voltage source 25, a resistor 26 is switched on, to generate a density correction signal (in the form of an output current) at the reference concentration of sulfur present on the Sum signal of the exponential signal taking into account the density at the measured temperature and the reference sulfur concentration j and des the reference sulfur I set by the potentiometer based on the signal taking into account the concentration, the potential

j tiometer 23 for generating a density correction signal setting

j is bar.

: An output terminal of the amplifier 12 is via a potentiometer ; 27 grounded so that the range of the sulfur concentration can be adjusted is cash. The wiper 28 of the potentiometer 27 is with a

! Input terminal of a voltage-current converter 30, the one

; Contains linearizing circuit, via a circuit 29 with variable

': Time is constantly connected in order to avoid the statistical error of the radio

'to be able to consider active source. The output signal

e _{oo of} the voltage-current converter 30 is applied to the input terminals of a dividing circuit 31, to the other two input

- 17 10 9 8 17/186 /.

clamp the first output signal e * jf ρ of the voltage-current converter 22 is applied, so that after a dividing process e _S o / ^e i _P ^an output signal e " _{N is present} via the output terminals;> 2. The density converter 21 is provided with output terminals 33, one of which

ι density signal corrected with respect to the reference temperature

ι is removable.

I The measuring device works as follows. If a compound

Target made of silver and tin with an area ratio of 50: ^ 0 j the primary radiation of the radioactive source 8 (Am) of the sulfur : concentration detector 7 is irradiated, it emits fluorescence

! X-rays with an energy of about 2j5 * 7 KeV, which pass through

ί the "ratio of the concentrations of carbon and hydrogen j in which petroleum (petroleum) is not influenced in any way, but only by the concentration of sulfur. Be accordingly

! that is, through the sample, for example petroleum, in the measuring tank ι penetrating rays absorbed by the sample liquid.

and the transmitted X-rays can be observed by means of the ionization chamber 11 which gives an output signal in accordance with the equation (1). In this equation, the expression / U _t . + R / U "/ l + R corresponds to the mass absorption coefficient L-

/ Ii / Kj

¹ cient of the hydrocarbon compound mixture. If this expression is replaced by AUtt, then equation (1) can be rewritten as

Ευ exp - \ t £ (^ usg - / Uo _c ) Cs _s + / ^U _CH J

At other times the density detector is in operation, around the clock of the sample chamber flowing through the concentration detector 7

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determine and to generate a frequency output signal proportional to the density. Since the frequency output signal is taken at a temperature prevailing in the density detector, it must necessarily be corrected for the reference temperature. The frequency output signal is therefore corrected in the density converter 21 by means of the output signal of the temperature measuring resistor 17. In order to further correct the frequency output signal with regard to the density prevailing in the sulfur concentration measuring tank, .isfc convert the output signal of the temperature measuring resistor 18 arranged on the sulfur concentration detector 7 into a correction voltage signal with the aid of the bridge circuit 19; the output signal of the bridge is applied to the density converter 21 in order _{to generate an output signal e J 1} (e.g. a voltage of 0-10mV at a density of £ - 0.8 - 1.0g / cm). This output voltage corresponds to the density signal at the temperature at which the concentration of sulfur was measured.

The output voltage e | - is converted into an equal voltage signal ei ₂ (e.g. e ^ ₂ = 1 - 5 V at a density of j = 0.8 - 1.0 g / cnr) and a signal e ° - * that is proportional to the exponential signal, the corresponds to the signal e \, and is expressed by the following equation (5), the conversion being carried out by means of the voltage-current converter 22 which is equipped with a puncture conversion circuit, not shown. This exponential signal el, (approximately 1-5V) is applied to the potentiometer 2} to adjust the density correction signal to provide an exponential output given by equation (5).

- 19 -

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e / = R ¹ / IO e'i.irs'AH ^{5 0} SZ ⁺ Ah /

-O.8t ^ C ₇ US ₃ - / U _CH ) C _{sz + /} u _CH | J (5),

-IO e

where C _{gz is} the reference concentration (in%) of sulfur and R ¹

! represent the resistance for the voltage conversion.

The DC voltage source 25 and the potentiometer 24 for setting! len of the reference concentration of sulfur work together, j around a constant expressed by the following equation (6) To create tension. ι

e "= Rtto e JV ^US S""/ ^U CH 'SZ ⁺ Z ¹ CH / (6).

Z v. J

The voltage eH generated by the potentiometer 23 for generating a density correction signal and the voltage e- * generated by the potentiometer 24 for setting a reference sulfur concentration * are added to provide the following voltage signal.

R'l _{0 e} - ⁰ ' ^Sl i ^ i- ^ c «) ^C 5J -Ah}.

\ (° / ^u s- Ah) ^c sz + AhJ (7).

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- 20 The voltage signal given by the equation (7) is given by passed through resistor 26 to produce a current signal representative of the reference concentration of sulfur, as indicated by the the following equation (8) is shown.

/ u _CH ) c _sz + / u

(8th)

Becomes the sulfur concentration signal given by the equation (4) Is from the reference concentration current signal of sulfur

deducted
(Equation (8) y, the difference is:

Δ Is = Is - Io β

-Λ {</ ^u s - / ^u ch> ^c sz7 ^u ch}

Io e-Λ (</ ^u S - / ^U CH ^{) C} CZ ⁺ A

- Io e

This difference signal Λ Is is amplified by the amplifier 12 with a high input resistance to produce an output signal e. which is proportional to the product of Als and the resistance of the feedback resistor 1J> . This output signal e is set by means of the potentiometer 27, and the output voltage of the wiper 28 is fed to the voltage-current converter 30 with a linearizing circuit (not shown) via the time constant circuit 29 for setting the statistical error, so that a linearized output signal e ₂ is present.

Since the signal e. the difference between the concentration signal and corresponds to the reference concentration signal of sulfur, the width of the signal e is very narrow, and therefore ir-t is the curvature

-21-

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BATH ORIGINAL

- ₂₁ _. 204950Q

the characteristic Δ Is with reference to the concentration of sulfur very low, so that it is very easily possible to use the signal e.

to linearize with the help of a simple linearization circle, whereby the linearization circuit can include a diode as a feedback circuit for the amplifier 12.

The Pign. 6 to 10 show the relationship between the concentration of sulfur and the ratio of e _g "/ e" (where e _{N is} equal to e j at a density of ^ = 0.8 g / cm) for different ranges

j is the sulfur concentration, namely 0 - 1%, 2 - j5 #, j5 - 4 $ and

j $ 4-5; in the representations of FIGS. 6-10, the density is as

Parameters have been used. :

From the figures it can be seen that an approximate value of e _{2 is given} by the following equation (10):

= Ko

-o.8) J (c _s -c _sz ) (ίο)

where Ko and K are constants.

Through the action of the dividing circuit jjl, the linear output signal e P ₂ , which takes into account the density and is provided by the voltage-current converter 22 equipped with a function circuit, is converted into a signal 1 + K (^ -0.8), and that by; the Equation (10) given signal e ″ ₂ given signal is then divided by the signal I ₊ K (^ - 0.8) as shown by the following equation (H), whereby an output signal e_j. is provided that the concentration of sulfur after a train-

- 22 - ^: 109817/1864

density (/ = 0.8g / cm ^) indicates:

e 1 _m (11)

SN 1 + K (/ -0.8)

= ^Ko 1 ^{1 + K} (/ - ° ⁸ )) ( ^C 3 ~ ^C SZ ⁾
1 + K ( f -O.ö)

^{= Ko} ( ^c s - ^c sz>, (ii)

By modifying equation (11) one obtains:

/ (12)

SN '

The left expression ^ö SN / ^e SN of this equation corresponds to the ordinate in the Pign. 6-10 so that the value of K can be determined from these figures and equation (12). For example, in the case of a sulfur concentration range from 0 to 1 # (Fig. 6), ^e op / ^e g is equal to 1.08 with / * = 1.0 g / cnr and Co = 1 · 0 # in equation (12) for K the value 0.4, which can be inserted in equation (11).

The FIGS. 6 to 10 also show that the ratio ^e _s2 / ^e sN approaches the value 1 and thus K approaches the value zero as the concentration Co of the sulfur increases. But that means nothing else than that the measurement error caused by the density is reduced.

Fig. 11 shows a modified measuring circuit of this invention, wherein

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'all the parts that came with parts from Pig. 5 are identical, are provided with the same reference numerals. The circuit of FIG. 11 differs from the circuit of FIG. 5 in the following points. The reference concentration signal of the sulfur at the reference density is subtracted from the measured sulfur concentration signal in the input circuit to the amplifier 12 with a high input resistance. The difference signal is amplified and linearized by the linearizing circuit 30 in order to provide an output signal e ^f _g2 . An output signal e f, the dee by appropriate setting Exponentialausgangssignales ^e f * of the voltage-current converter 22 is generated, 'is subtracted ₂ ^, and' from the output voltage e, the difference signal thus obtained is dividend by the signal e ^ ^_2! dated, which goes back to the density signal. It should be pointed out here again that the voltage-current converter 22 is equipped with a function conversion circuit (not shown). Such a difference signal is also achieved when the linear:}. -

I '

sierkreis 30 has a wide operating range. ^;

i j

! Fig. 12 shows a partial circuit diagram of a modification of the circuit according to FIG. 11. In this modification, the set voltage et of the exponential output voltage e ^ _ from the voltage-current converter 22 is not _{added differentially to the output voltage e '2 of} the linearizing ^{circuit 30:} but the voltage eP is added differentially to the input of the linearization circuit J50. On the other hand, the voltage eP can also be given to the output of the potentiometer 127 for setting the range.

1 09817 /

. ₂₄ . 20A9500

If the linearized signal relating to the density is applied to the dividing circle, as in this embodiment, where the range of the density is very narrow, for example from 0.8 to 1.0 g / cm, ie with a difference of 0.2 g / cm ^ the course of the expolential density corresponds essentially to a straight line, so that the curvature of the characteristic is only 2% of the curvature of the further density area. Accordingly, such a characteristic can be regarded as a straight line, even if it is linear! -; sized signal is applied to the potentiometer for setting the density correction signal and to the dividing circuit Jl, the resulting error is negligibly small.

Although in the embodiment described so far in a density range from 0.8 to 1.0 g / cnr a reference density of 0.8g / cnr has been selected, any reference density can be selected, as long as the reference density is in the range described above. It should also be noted that the density range does not apply to the Range is limited from 0.8 to 1.0g / cnr, but both above as well as below this specified range.

Although the range width of the sulfur concentration was 1% in the embodiment described, this width can be smaller or larger.

In the embodiments described above, there is a densitometer of the vibration type has been used as a density detector because it has a allows high accuracy and is suitable for continuous measurement.

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_25-204950Q

Any density detector can of course be used.

The measuring circuit described above has an amplifier for amplifying the concentration signal of the sulfur or another element in the hydrogen sulfide compound or in the Hydrogen sulfide compounds, furthermore a linearization circuit for linearizing the output signal of the amplifier, a dividing circuit for dividing the output signal of the linearizing circuit by an on the density signal of the hydrocarbon compound referenced signal, switching means for converting the density signal into an exponential function of the density and the reference concentration as well as the concentration signal of the sulfur or other element and means for differential application the exponential function and the sulfur concentration signal to the input of the amplifier or to the input of the dividing circuit. With this arrangement, a device for determining ■

with

the concentration ^ have been created, by means of the / great measurement accuracy, the concentration of sulfur or other impurities can be measured in hydrogen sulfide compounds and in which a required density compensation is possible without a logarithmic amplifier must be used.

The FIGS. I3 and 14 show in detail a signal generator such as

it is used in connection with the present invention, which:; a housing 40 with a base body 41 and two closures 42 and 4 ^ which releasably at opposite ends the main

- 26 -

109817/1864

- 26 body are attached. A frame 5I is in the main body 41 contain. A central opening 52 in the frame 51 works with covers 53 and 54 together on different frame sides, see above that a measuring tank 50 is determined by the components 51, 53 and 54.

After Pig. 14 is the frame with an inlet opening 55 for the; Provided sample liquid, there is also a diffuser 56 at the inlet passage of the chamber 57 provided in the measuring tank 50 and an outlet opening 58 trained. As from the enlarged views of the Pign 15 16 and 16, the diffuser 56 has a cylinder 561, a tapered opening 563, and a thermoset opening 564 in FIG of the bottom wall 562 of the cylinder 56I which is coaxially aligned with the axis of the cylinder 56I. Two rectangular windows 565 and 566 are of the same size on the circumference of the cylinder; 56I trained. According to the Pign. 14 and 15, the diffuser is arranged in the vicinity of the inlet opening of the chamber 57 in the measuring tank 50, the windows 565 and 566 on the inner circumferential surface of the chamber. mer 57 is aligned. The diffuser can be of various types. For example, round windows can be the rectangular windows replace and can form the bottom plate 562 as a hollow hemisphere will. It is only necessary to distribute the liquid evenly and to direct it in such a way that it flows to the Outlet opening flows towards. The frame 51 can be made of a corrosion-resistant Material such as stainless steel, while the covers 53 and 54 are made of fine material, which lets through the fluorescent X-rays with a small attenuation coefficient and is not deformed by heat or petroleum

- 27 - j

109817/1864

204950Q

- 27 is still being destroyed. A suitable material is polyethylene.

A radioactive source 60 is in FIG. 13 to the left of the measuring tank 50 an-j orderly. The source has a housing component 61 with a window 62 and a ring 63 for fastening the window 62 on the frame

j men 6l on. The window 62 provides a cover for the hermetic i

! Seals the interior of the source 60 and is in close contact

Imitated with cover 53 to reinforce it when the source is attached to tank 50. The window '62 is preferably made of a metal with an extremely low absorption coefficient 1 for radioactive radiation, for example beryllium. Inside the source 60 is a frame 70 of cup-shaped form ί ^; (cf. FIGS. 17 and 18) and has a holder 72 for holding a radioactive substance 71, four radially extending

Ribs 73 to 76 for supporting the radioactive substance 71 and eiii jTarget 77 on the inner bottom wall. The radioactive substance 71 is held in the holder 72 by means of a threaded bolt 78 in the vicinity of the focal point of the spherical composite target 77, which is composed of a metal M-, which forms the inner frame 70 itself, and of 45 ° metal foils M ₂ , which on the

inner surface are glued at a distance of 45 °. As a radio

24l
The active substance is preferably Am, while the metals M _{1 and M 2 of} the target are tin and silver, respectively.

A detector 80 in the form of an ionization chamber is attached to the right side of the measuring tank 50. The detector 80 has a potential electrode 81, a collector electrode 82 and a

- 28 109817/1 86A

Output terminal 83 and a window 84 made of the same material There is Vrie the window 62 of the source 6O. The inside of the detector

80 1st sealed and filled with a gas such as xenon to protect the To increase ionization current. The measuring tank 50 is by means of a Lei-i device 90 heated by steam. The tank is still with a Wi; The stand 100 for measuring the sample temperature for performing temperature compensation and is provided with a terminal box 110. Appropriate O-rings (represented by small black circles) are used to prevent leakage. :

To assemble the signal generator, the window covers 53 and 54 are first attached to opposite sides of the tank frame 51, and then the temperature measuring resistor 100 is inserted. Thereafter, the frame 51 is inserted into the main body 41 to complete the measuring tank 50. The inner frame 70 ^! with the radioactive substance 71 in the holder 72 is introduced into the housing 60 and the window 62 is put on. The sources- ! assembly 60 is attached to the left side of the measuring tank with screws, as can be seen in Fig. IJ. After that, gas is in

the detector 80 of the electrode 8l and the collector electrode 80 on

at ;

and the detector assembly / the right side of the measuring tank 50 is attached. After the necessary pipe connections and electrical connections have been made, the covers 42 and 4 ^ are opened. sets to complete the assembly. \

When operating the device, the liquid to be measured is through the inlet opening 55 let into the chamber 57 of the measuring tank 50.

- 29 -

10981 11 1 8 6 Λ

The arranged at the entrance of the chamber 57 diffuser 56 distributes the

I Flow of liquid in three directions. A small partial flow occurs j straight into the chamber through the opening 564 in the base plate 562, while two other partial flows along the circumferential surface the chamber 57 are conducted. In this way the j Liquid the chamber 57 evenly, as in Fig. 19 by the | Arrows is shown, so that in the chamber itself no jam on-i occurs. !

If the liquid is viscous, such as heavy oil, it will be

heated by steam flowing through line 90 to reduce viscosity. The radiation of the radioactive substance 71 spreads to the left in FIG. 13 and meets

j the target 77, the fluorescence X-ray radiation in the opposite direction:

set direction radiates. The energy level of the X-rays is determined by the area ratio of silver to tin in the composite Target determined. The X-rays are absorbed; and therefore by the concentrations of carbon, hydrogen, Sulfur and other substances contained in the measuring liquid are weakened and finally reach the detector 80. A measuring liquid can e.g. be petroleum. But since, as has already been explained above, the mass absorption coefficient of carbon and hydrogen are the same for fluorescent x-rays, the ionization current generated in the detector changes in Ab- j

dependence on the concentration of sulfur, so that a measurement the concentration of the sulfur contained in the petroleum is possible.

- 30 109817/1864

The new signal generator has the following advantages: In particular, the measuring tank 50, the radioactive source and the detector 80 are constructed as independent assemblies; it is possible to change the pressure j

in the source and in the detector 80 the liquid pressure in the measuring tank j

j to equalize. In this way, the pressure differences between i see the opposite faces of the covers to avoid them are reduced from breakage even if the covers 53 and 54 consist of a polyethylene plastic, which although a high | Permeability to radioactive radiation, but poor mechanical strength. In addition, these units easily assembled and disassembled. Corrosive gases such as hydrogen sulfide can also enter or sulfuric acid in the signal generator so that its properties cannot change due to corrosion. The one at the liquid inlet opening of the Diffuser arranged in measuring tanks ensures a uniform and constant flow of the admitted liquid, so that always the sulfur content of fresh liquid is measured. Because the target has the shape of a hemisphere and because the radioactive one Substance is arranged essentially at the focal point of the curved target, the emerging from the substance 71 become radioactive Rays used in an optimal way.

Furthermore, the windows 62 and 84 reinforce the covers 53 and 54, when these windows are in firm contact with the covers 53 and 54 of the measuring tank after assembly. The close contact the windows and covers prevents precipitation

- 31 -

1098 17 / 186A

- J) X -

I from moisture and a settling of dust, so that the permeability ! properties for radioactive radiation are not changed. Heating the measuring tank 50 by means of steam ensures a smooth Flow of measuring liquid through the tank. When the temperature the liquid to a constant temperature value by means of the temperature measuring resistors is controlled, errors caused by temperature changes can be eliminated.

While the invention is based on several specific exemplary embodiments has been shown and described, it is clear that many changes and deviations are possible without departing from the basic * thoughts of the invention deviate. .

1098 17/1 86A

Claims (15)

Claims [1. / Device for determining the concentration of a in hydrocarbon compounds containing element, in particular an element with a larger mass absorption coefficient than that of carbon and hydrogen in hydrocarbon compounds, characterized by emitting radiation radioactive source (1) with an energy level of 60 to 100 KeV, by an irradiated with the radioactive radiation Target (2) for the emission of fluorescent X-rays with an energy level of 23 to 24.5 KeV and a detector for the compounds penetrated fluorescent X-rays. 2. Apparatus according to claim 1, characterized in that the Hydrocarbons or the hydrocarbon compound petroleum or one of its refined products is and the element is selected from a group consisting of those in the coal -2- 109817 / Hydrogen contains sulfur, chlorine, nickel and lead consists. 3. Apparatus according to claim 1, characterized by a Dlcht ^ - detector (I5) to determine the density of the hydrocarbons ^ substances or the hydrocarbon, a measuring circuit (12) for amplifying one of the detector (11) for X-rays incoming signal, a linearizing circuit (30) for linear! - j sizing the output signal of the measuring circuit, a dividing | circuit (31) for dividing the output signal of the linearizer circle (30) through an au.f the diet signal of the density detector (15) related signal, switching means for converting the j density signal into an exponential signal representing a puncture j Density and a comparison concentration of the signal of the element is the same as the concentration signal of the element; ■ i andtaureh means for the differential addition of the exponential j signals to the concentration signal. j 4. Apparatus according to claim 1, characterized in that the target (2) is a composite target which consists of a ' ■ 1 combination of two metals from the group silver, tin, indium; and cadmium. ', 5. Apparatus according to claim 1, characterized in that the. Target made of a single metal from the group consisting of indium and cadmium. ; -3-109817 / 1864 j- 20-4950Q 6. Apparatus according to claim 1, characterized in that the dai3 Detector for the X-ray radiation includes an ionization chamber (11). 7. Concentration measuring circuit for a device for determining ^ tion of the concentration of compounds of an element in hydrocarbon \ or Kohlenwasserstoffverblndungsgeraisch; with the help of a fluorescence X-ray absorption! treatment by the detectors measuring the carbonic hydrogen compounds, characterized by an amplifier (12) for amplifying the signal coming from the concentration detector (11), a linearizing circuit (350) for linearizing the output | signals of the amplifier (12), a dividing circuit (31) for | Dividing the output signal of the linearizing circuit by; one related to the density signal of a density detector (15); Signal, switching means for converting the density signal into an exponential signal, which is a point on the density and a comparison concentration of the element is exactly like the concentration signal of the element and by means of differentiating Addition of the exponent! AIsignaIs to the concentration signal. 8. Circuit according to claim 7, characterized in that the exponential signal is applied to the input of the amplifier (12) is. 9. Circuit according to claim 7, characterized in that the exponential signal is applied to the input of the dividing circuit (31) is. 10981 11 1864 20Α9500 10. Circuit according to claim 7, characterized in that the exponential signal to the input of the linearizing circuit (30) is laid. 11. dividing circuit according to claim "J, characterized in that the sum signal of a density correction signal derived from the exponential signal and a comparison density and a comparison concentration of the element taking into account second exponential signal is applied differentially with the concentration signal to the input of the amplifier (12). 12. Circuit according to claim 7, characterized in that the exponential signal which is a function of a comparison density and the reference concentration of the element, and a concentration signal differentially to the input of the amplifier and a second exponential signal ^ which is a puncture of a comparison density and a comparison concentration of the element, differentially to the output of the amplifier (12) is applied. 13. Signal generator for use in a device for Determination of an element in hydrocarbon compounds, characterized by radioactive radiation emitting radiation Source (1) with a curved target (77). one essentially radioactive substance (7I) arranged in the focal point of the target · a detector with a potential electrode (8l) and a collector electrode (82) having Ionization chamber and one at opposite ends with 1098 17/1 8 6 U -sr- ₃₆ ' 20A9500 Penstern (53> and 54) provided measuring tank (50), the windows consist of a material with a low absorption coefficient for radioactive radiation and source and detector
have a sealed construction and are located on different sides of the tank (50). 14. Signal generator according to claim 1J>, characterized in that the source (60) and the detector (80) are arranged at opposite ends of the tank that the emission side of the source (60) and the radiation side of the detector (80) in 1 direct contact with the windows (53,54) of the measuring tank (50) stand. ! 15. The device according to claim Ij5, characterized by a measuring tank through which the hydrocarbon compounds or the
Hydrocarbon compound flows through it steadily, the
Tank near the inlet opening with a diffuser (56)
provided for the hydrocarbon compounds 1st. 1098 1 11 1 864