JP3134042B2 - Sludge component ratio measuring device and component ratio measuring method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sludge component ratio measuring device, and more particularly to a device capable of measuring the component ratio of sludge containing air bubbles with high accuracy.

[0002]

2. Description of the Related Art In sludge incineration equipment, it is necessary to know the component ratio of sludge to be introduced into an incinerator in order to optimize combustion control of the incinerator. Sludge is a mixture of water, organic matter, and inorganic matter, and often contains air bubbles. The component ratio of water, organic matter and inorganic matter in the sludge is usually measured by the method described below. Further, in this method, since each component ratio is obtained from the weight difference, it is not necessary to consider the volume content of bubbles. The component ratio may be represented by a volume ratio or a weight ratio. Here, the component ratio is finally determined as a volume component ratio (volume content).

[0003] First, the collected sludge (W) is weighed into a weighing bottle, washed with an as little amount of water as possible in an evaporating dish or crucible, and evaporated to dryness on a water bath. Next, this is 105
After drying at ~ 110 ° C for 2 hours and allowing it to cool in a desiccator, weigh the mass and determine the difference between this mass and the mass of the evaporation dish (Wd).
The water weight content is calculated from

Rw = (Ww / W) Ww = W-Wd where Rw: water weight content W: weight of collected sludge (g) Ww: weight of water contained in collected sludge (g) Wd: evaporation to dryness Weight of sludge after evaporating (g) Further, the sludge after evaporating to dryness was ash-ignited at 600 ± 25 ° C. for 1 hour using an electric furnace with the evaporating dish, allowed to cool in a desiccator, and weighed. From the difference (Wa) between this mass and the mass of the evaporating dish, the organic substance weight content is calculated.

Ro = (Wo / W) Wo = Wd-Wa where Ro is the weight content of organic matter and Wo is the weight of organic matter contained in the collected sludge (g). Wa is the sludge after evaporating to dryness. Subsequent weight (g) The weight content of the inorganic substance is determined from the residue on ignition (Wa) according to the following relationship.

Ra = (Wa / W) where Ra is the weight content of inorganic substance. Each of these weight content rates Rw, Ro, and Ra is the volume content rate T.
w, To, and Ta, respectively.

Tw = Rw / (Rw / ρw + Ro / ρo +
Ra / ρa) To = Ro / (Rw / ρw + Ro / ρo + Ra / ρa) Ta = Ra / [(Rw / ρw + Ro / ρo + Ra / ρ)
a) ρa] where, Tw: water volume content To: organic substance volume content Ta: inorganic volume content ρw: water density (g / cm ³ ) ρo: density of organic substance (g / cm ³ ) ρa: Density (g / cm ³ ) From the above, each volume content of water, organic matter, and inorganic matter is obtained, but this is a value that does not take into account the volume of bubbles contained in the sludge, Does not match the component ratio.

[0008]

When measuring the component ratio of sludge using the above-mentioned prior art, it takes a long time for these pretreatment steps, such as evaporating the collected sludge to dryness and heating. . Therefore, there is a problem that the measurement result is obtained several hours later.

On the other hand, the component ratio of the sludge is relatively stable, but when heavy rain falls, the mud flows into the sewer pipe from the drainage ditch of the road, and the inorganic volume content of the sludge rapidly increases. To increase. That is, the component volume ratio of the sludge measured by the above-described conventional technology does not necessarily reflect the present condition, and is not suitable for optimizing the combustion control of the sludge incinerator. However, a method for measuring the component ratio of the collected sludge in a short time has not been developed at present.

Furthermore, in the prior art, since each component of the sludge put into the furnace cannot be determined by the volume ratio, it is necessary to measure the sludge weight with a quantitative meter before putting it. Accordingly, an object of the present invention is to provide a component ratio measuring device capable of measuring the component volume ratio of collected sludge in a short time.

[0011]

Means for Solving the Problems To solve the above-mentioned problems, a sludge component ratio measuring apparatus according to the present invention comprises (a) a pressure-resistant container for storing sludge, and (b) a pressure-resistant container contained in the pressure-resistant container. Pressure applying means for applying an external pressure to the sludge, (c) an internal pressure measuring means for measuring the internal pressure of the pressure-resistant container, and (d) a neutron source for irradiating the sludge contained in the pressure-resistant container with neutrons,
(E) a neutron detector for detecting neutrons scattered by sludge, (f) neutron counting means for counting the counting rate of detected scattered neutrons, and (g) externally applying gamma rays to sludge in the pressure vessel. A gamma ray source, (g) a gamma ray detector for detecting gamma rays transmitted through sludge, (i) gamma ray counting means for counting the count rate of the detected transmitted gamma rays, and (j) at least two different pressure conditions. Based on the counted neutron count rates and the gamma ray count rate counted under any one of these pressure conditions, the volume of organic matter, inorganic matter, moisture, and bubbles contained in the sludge is calculated. Calculating means for calculating the content rate.

The method for measuring the component ratio of sludge according to the present invention comprises the steps of: (a) a first pressure P serving as a reference and a second pressure P different from the first pressure P;
The sludge is irradiated with neutrons under each condition of the pressure P ₀ , and the neutron counting rate N,
The N ₀ were measured, the ratio of these measurements (N ₀ / N)
Calculating the volume content rate Sv of bubbles contained in the sludge under the condition of the first pressure based on the following equation: Sv = P ₀ (N ₀ −N) / (P ₀ N ₀ −PN) ( b) irradiating the sludge with gamma rays under the condition of the first pressure P;
By measuring the count rate G ₂ of the gamma rays transmitted through the sludge, the measured gamma ray count rate G ₂ and the first pressure P
The ratio (G ₂ / G) of the gamma ray counting rate G ₁ and the gamma ray counting rate obtained for the sample containing only air under the condition of
₁ ) and calculating the average density ρ of the sludge based on the bubble volume content Sv using the following equation: ρ = [ln (G ₂ / G ₁ )] / (μX) + (2Sv−
1) ρv where μ is the mass attenuation coefficient (cm ² / g), X is the gamma ray transmission path length (cm), and ρv is the density of air (g / cm).
³ ), respectively. (C) The ratio (N / N ₁₎ between the neutron count rate N measured under the condition of the first pressure P and the neutron count rate N _{1 of} only water previously determined under the condition of the first pressure P. ), The average density ρ of the sludge, and the volume content Sv of the air bubbles, and calculating the volume content So of the organic matter contained in the sludge under the condition of the first pressure P using the following equation. And So = ρwHwMo [ρ−ρa + (ρa−ρv) Sv +
(Ρa−ρw) (N / N ₁ )] / [(ρo−ρa) ρw
HwMo + (ρa−ρw) ρoHoMw] where ρw is the density of water (g / cm ³ ), ρo is the density of organic matter (g / cm ³ ), and ρa is the density of inorganic matter (g / cm ³ ).
³ ), ρv is the density of air (g / cm ³ ), Hw is the number of hydrogen atoms contained in one molecule of water, Ho is the number of hydrogen atoms contained in one molecule of organic substance, Mw is the molecular weight of water, and Mo is the molecular weight of the organic substance. , Respectively. (D) The ratio (N / N ₁ ) of the neutron count rate N measured under the condition of the first pressure P to the neutron count rate N _{1 of} only water previously determined under the condition of the first pressure P ) And calculating the volume content Sw of the water contained in the sludge under the condition of the first pressure P using the following equation based on the organic material volume content So: Sw = [ρwHwMo (N / N) ₁ ) -ρoHoMwS
o] / (ρwHwMo) (e) On the basis of the bubble volume content Sv, the organic matter volume content So, and the water volume content Sw, the sludge under the condition of the first pressure P is obtained using the following equation. A step of calculating the volume content Sa of the contained inorganic material; and Sa = 1− (Sv + Sw + So).

In the present invention, the sludge component ratio is measured using two types of radiation (neutron rays and gamma rays). There are a scattering method and a transmission method as measurement methods based on the positional relationship between the radiation source, the sludge, and the detector. In the scattering method, a source and a detector are located in the same direction with respect to sludge. The detector detects the radiation radiated from the radiation source, which is multiply scattered by the sludge and turned around 180 degrees. In the transmission method, sludge is located between a radiation source and a detector, and among the radiations emitted from the radiation source, those transmitted through the sludge are detected by the detector. In the present invention, neutrons are measured by a scattering method, and γ-rays are measured by a transmission method.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The methods for measuring the volume content of bubbles, the volume content of organic substances, the volume content of water, and the volume content of inorganic substances using radiation will be described below with reference to FIG.
FIG. 1 is a block diagram showing a sludge component ratio measuring apparatus according to a first embodiment of the present invention.

The sample container 2 contains the sludge 1 therein, and the pressure outside the sample container 2 is transmitted to the sludge 1 by forming the upper (bottom) surface with a rubber film 3. Further, even when the sludge volume changes due to a difference in pressure conditions applied to the sludge 1, it is possible to cope with the elongation of the rubber film 3. The side portion of the sample container 2 is made of metal such as stainless steel so as not to be deformed when pressure is applied to the entire sample container 2. Sample container 2
Is stored in the pressure vessel 4 in a state filled with the pressure medium 6. The pressure medium 6 transmits the pressure generated by the pressure generator 5 to the inside of the pressure vessel 4 and to the sample vessel 2.
The pressure inside the pressure vessel 4 is measured by the pressure sensor 7.

Fast neutron rays and γ-rays emitted from the neutron source 10 and the γ-ray source 12 are supplied to the sludge 1 from outside the pressure vessel 4.
Irradiate toward Fast neutrons emitted from the neutron source 10 are multiple-scattered by the sludge 1 to become thermal neutrons, and are detected by the neutron detector 11. The output signal of the neutron detector 11 is amplified by the preamplifier 14 and
After the noise signal is removed in step (1), the counter 18 counts. Among the γ-rays emitted from the γ-ray source 12, sludge 1
Γ-rays that have passed through are detected by the γ-ray detector 13. The output signal of the γ-ray detector 13 is amplified by the preamplifier 15, the noise signal is removed by the wave height discriminator 17, and the output signal is counted by the counter 19. Finally, the measurement results of the pressure sensor 7, the counter 18, and the counter 19 are arithmetically processed by the arithmetic processor 20 to determine the component ratio of the sludge 1.

[Measurement of Bubble Volume Content] The volume content of bubbles is measured by neutron measurement by a scattering method. Fast neutrons with high energy emitted from the neutron source 10 are scattered by the sludge 1 and gradually lose energy.
Since the moderating power for neutrons is much higher than hydrogen by other elements, neutrons lose energy by colliding mainly with water in the sludge 1 and hydrogen atoms constituting organic matter, and eventually lose energy. Becomes thermal neutrons with very low energy. Detection efficiency of neutron detector 11 ⁽³ the He counters) is high for thermal neutrons is lower for fast neutrons, the water eventually neutron count rate (= the neutron count / measurement time) is sludge 1 The amount reflects the organic matter content ratio. Effective range volume Ve (cm) of the neutron detector 11
³ ) Since there is a proportional relationship between the number of hydrogen atoms Nt (pieces) contained in the sludge 1 and the neutron counting rate N (cpm) of the measuring device 17 measured by the neutron detector 11, N = KNt (1) where K represents a proportionality constant (cpm / piece).

The sample container 2 is a container filled with the collected sludge 1, and has a structure capable of transmitting the pressure outside the container to the sludge 1. Size of sample container 2 (internal volume V (cm
³ )) is sufficiently larger than the effective range volume Ve of the neutron detector 11, and the sludge volume does not become smaller under any pressure conditions. Therefore, the volume Ve
The relation between the sludge component ratio and the neutron count rate in the inside is described.

The first pressure P (a) within the effective measurement range volume Ve
tm) (reference pressure), the volumes of air bubbles, water, organic substances, and inorganic substances are expressed as Vv (cm ³ ), Vw (cm ³ ), Vo
(Cm ³ ) and Va (cm ³ ), Vv + Vw + Vo + Va = Ve If both sides are divided by Ve, bubbles under the condition of the first pressure P,
Each volume content Sv, Sw, So, of water, organic matter, inorganic matter,
The following equation (2) is obtained as the relational expression of Sa.

Sv + Sw + So + Sa = 1 (2) Further, since a series of measurements is performed with the sludge 1 sealed in the sample container 2 and the volumes of water, organic substances, and inorganic substances are almost constant regardless of pressure, The following relationship holds during the measurement.

Vo = mVw (0 ≦ m <1) (3) Va = nVw (0 ≦ n <1) (4) where m and n are constants, and the main component of sludge 1 is generally Since it is water, it may be assumed as in the above equation. By substituting the two sides of Equations (3) and (4) by Ve into Equation (2), if Sv + (1 + m + n) Sw = 1 m + n = k (constant), then Sv + (1 + k) Sw = 1 (5)

Since the sludge component containing a large amount of hydrogen is water and organic matter, if the number of hydrogen atoms contained in water and the organic matter in the volume Ve is Nw (number) and No (number), respectively, Nt
Is expressed as Nt = Nw + No. Here, the hydrogen density is defined. Hydrogen atom density of water (pieces / cm ³⁾ and Dw, the organic hydrogen atom density (number / cm ³⁾ and Do, Dw = Hw [ρwNa / Mw] ... (6) Do = Ho [ρoNa / Mo ] (7), Nw and No are respectively Nw = Hw [ρwNa / Mw] (VeSw) No = Ho [ρoNa / Mo] (VeSo) In the above formula, Hw: the number of hydrogen atoms contained in one molecule of water, Ho: the number of hydrogen atoms contained in one molecule of an organic substance,
ρw: density of water (g / cm ³ ), ρo: density of organic matter (g / cm ³ ), Na: Avogadro number (pieces / mol),
Mw: molecular weight of water, Mo: molecular weight of organic matter. The numbers on the right side of the formulas (6) and (7) indicate the number of molecules of water and organic substances contained in the unit volume, and by multiplying this by Hw and Ho, the hydrogen density of water and organic substances can be obtained.

Accordingly, the number of hydrogen atoms Nt in the volume Ve is Nt = Nw + No = Hw [ρwNa / Mw] (VeSw) + Ho [ρoNa / Mo] (VeSo) = (NaVe / MwMo) (HwρwSwMo + HoρoSoMw) = (NaVeMw) (HwρwMo + mHoρoMw) Sw (from equation (3)). At this time, the neutron counting rate N is calculated by the above equation (1).
Thus, N = KNt = K (NaVe / MwMo) (HwρwMo + mHorpoMw) Sw.

Next, pressure is generated by the pressure generator 5 shown in FIG. 1 and the pressure is transmitted into the pressure vessel 4 by the gas or liquid pressure medium 6. The sample container 2 is accommodated in the pressure container 4, and the space between the pressure container 4 and the sample container 2 is filled with a pressure medium 6. The sample container 2 has a structure capable of transmitting the pressure outside the container (that is, inside the pressure container 4) to the sludge 1 as described above. By the way, in order to measure the inorganic substance volume content by the γ-ray transmission method, it is necessary that the γ-ray transmission path length in the sludge 1 is always constant, and the cross-sectional shape of the sample container 2 including the γ-ray transmission path Must not deform under any pressure conditions. Therefore, when γ-rays are radiated in the horizontal direction, the upper and lower surfaces of the sample container 2 are made of the rubber film 3 or the upper (bottom) surface is moved by a vertical piston mechanism, so that the sample container 2 A structure that can respond to the volume change of the sludge 1 while transmitting the external pressure to the inside of the sample container 2 is required.

Now, assuming that the pressure inside the pressure vessel 4 is increased from the first pressure P to the second pressure P ₀ (atm), the pressure is increased by the rubber film 3 on the top (bottom) surface of the sample container 2 or the piston mechanism. It is transmitted inside. Assuming that the volume of the bubble at the second pressure P ₀ is Vv ₀ (cm ³ ), the relationship of Vv ₀ = VvP / P ₀ (8) is established from Boyle's law. Since P ₀ > P, Vv ₀ <Vv, and the volume of the bubbles decreases, and accordingly, the volume V of the entire sludge 1 also decreases to V ₀ (g / cm ³ ). At this time, the internal volume of the sample container 2 is changed by the extension of the rubber film 3 or the movement of the piston, and the pressure is constantly transmitted to the sludge 1 while absorbing the volume change of the sludge 1 from V to V ₀ . Although the total volume of the sludge 1 changes to V ₀ , only the sludge (volume Ve) within the effective measurement range affects the neutron counting rate.

Within this volume Ve, the volume of the bubbles is reduced according to the relationship of equation (8), and the reduced amount is replaced by water, organic substances and inorganic substances while maintaining the relations of equations (3) and (4). I will do it. The sample container 2 has a sufficiently large V
_0> because it is Ve, the volume content Sv ₀ of bubbles in the second pressure P ₀ may calculate the volume Ve as a reference, Sv from equation _{(8) 0 = Vv 0 /} Ve = (VvP / P 0 ) / Ve = (P / P ₀ ) Sv (9) Accordingly, under the condition of the second pressure P ₀ , water, organic matter,
The volume content of the inorganic substance is also changed to Sw ₀ , So ₀ , and Sa ₀ , and can be expressed as Sv ₀ + Sw ₀ + So ₀ + Sa ₀ = 1 as in the above equation (2). Similarly, it is expressed by the following equation (10).

Sv ₀ + (1 + k) Sw ₀ = 1 (10) If k is deleted from Expressions (5) and (10), and Sv ₀ is deleted using Expression (9), the following Expression (11) is obtained. Get)

Sw ₀ / Sw = (P ₀ −PSv) / [P ₀ (1−Sv)] (11) Also, at this time, the number N of hydrogen atoms contained in the volume Ve
t ₀ (pieces) is Nt ₀ = (NaVe / MwMo) (HwρwMo + mHo)
ρoMw) Since Sw ₀ , the neutron count rate N under the condition of the second pressure P _0
From equation (1), ₀ (cpm) becomes N ₀ = KNt ₀ = K (NaVe / MwMo) (HwρwMo + mHoρoMw) Sw ₀ . Taking the ratio of the neutron count rates N and N ₀ under the conditions of the first pressure P and the second P ₀ , N ₀ / N = Sw ₀ / Sw = (P ₀ −PSv) / [ P ₀
(1-Sv)] By transforming this, the following equation (12) is obtained.

Sv = P ₀ (N ₀ −N) / (P ₀ N ₀ −PN) (12) The bubble volume content Sv under the condition of the first pressure P is obtained. Note that the bubble volume content Sv ₀ under the condition of the second pressure P ₀ is Sv ₀ = SvP / P ₀ from the equation (8).

As described above, the neutron count rate N under the condition of the first pressure P and the neutron count rate N under the condition of the second pressure P _0
0, and the first pressure P, by measuring the second pressure P _0, the bubble volume content Sv ₀ under conditions of the bubble volume fraction Sv and second pressure P ₀ at the conditions of the first pressure P Was required.

In the above description, the pressure is increased from the first pressure P to the second pressure P _0. However, the pressure is decreased and the second pressure P _{0 is} increased.
It may be. At this time, since P ₀ <P, Vv ₀ > V
v, the volume of the bubble increases. Accordingly, the volume V of the entire sludge 1 also increases to V ₀ , but the other points are the same as those described in the case where the pressure is increased. [Measurement of volume content of organic matter, water and inorganic matter] FIGS. 2 and 3
The procedure for obtaining each of Sw, So, and Sa based on the measurement results of the neutron count rate and the γ-ray count rate will be described with reference to FIG.

As in the case of the measurement of the bubble volume content, the component ratio of the sludge 1 under the condition of the first pressure P is set as in the following equation (2). Sv + Sw + So + Sa = 1 (2) First, the neutron count rate (cpm) is proportional to the number of hydrogen atoms contained in the sludge. Therefore, the components of the sludge to be considered are water containing a large amount of hydrogen and organic matter. Therefore, in the above equation (2), if SH = Sw + So and SSw = Sw / SH SSo = So / SH, the following relational expression is obtained. Note that SSw
Represents the mixing ratio of water based on the (water + organic material) portion in the sludge, and SSo represents the mixing ratio of the organic material based on the (water + organic material) portion in the sludge.

SSw + SSo = 1 FIG. 2 is a conceptual diagram for explaining the neutron counting rate. Hereinafter, neutron measurement on the modeled samples A, B1, B2, and B3 will be considered with reference to this conceptual diagram, and a neutron count rate for each sample will be defined to derive an equation representing the water volume content. However, the pressure condition is the first in any measurement.
Let the pressure be P.

Sample A) Water (Sw = 1): N ₁ (cpm) Sample B1) Sludge (0 <SSw <1, 0 <SSo <
1): N ₂ (= N) (cpm) Sample B2) Organic substance + inorganic substance + bubble (SSo =
1): N ₃ (cpm) Sample B3) Water + inorganic substance + bubble (SSw = 1): N
₄ (cpm) The neutron count rate N ₂ described above is equal to N measured in the measurement of the bubble volume content.

From the above equations (6) and (7), Do / Dw = ρoHoMw / (ρwHwMo). Since N ₃ and N ₄ measure the same volume of organic matter and water, the relationship between the two is expressed by the hydrogen density ratio Do / Dw as in the following equation (13).

N ₃ = [ρoHoMw / (ρwHwMo)] N ₄ (13) Further, the neutron count rates N ₁ and N ₄ have the relationship of the following equation (14) due to the difference in the volume ratio of water.

N ₄ = (1−Sv−Sa) N ₁ (14) Next, referring to FIG. 3, mixing of water and an organic substance in the (water + organic substance) portion in the sample B1 from the neutron count rate N _2. The fact that the ratio [SSw (or SSo)] is determined will be described.

FIG. 3 shows the mixture ratio of water and organic matter [SSw (or SSo)] in the (water + organic matter) portion of sample B1 on the horizontal axis, and the neutron count rate on the vertical axis, and the water and organic matter FIG. 4 is a characteristic diagram showing the dependence of the neutron counting rate on the mixing ratio of the neutrons. Now, since SSw has changed from 0 to 1 and the neutron count rate has changed from N ₃ to N ₄ , N ₂ of sample B1 is expressed as follows.

N ₂ = N ₃ + (N ₄ −N ₃ ) SSw = N ₃ + (N ₄ −N ₃ ) [Sw / SH] = N ₃ + (N ₄ −N ₃ ) [Sw / (Sw + So) _{] = N 3 + (N 4} -N 3) obtain [Sw / (1-Sv- Sa)] following equation solving for Sw (15).

Sw = [(N ₂ −N ₃ ) / (N ₄ −N ₃ )] (1−Sv−Sa) = (ρwHwMoN ₂ −ρoHoMwN ₄ ) (1−Sv−Sa) / [(ρwHwMo−ρoHoMw) ) N ₄ ] (from equation (13)) = [ρwHwMoN ₂ −ρoHoMw (1-Sv-Sa) N ₁ ] / [(ρwHwMo−ρoHoMw) N ₁ ] (from equation (14)) (15) From equation (2), 1−Sv−Sa = Sw + So. Therefore, substituting this into equation (15) and rearranging Sw allows the following modification.

Sw = [ρwHwMo (N ₂ / N ₁ ) −ρoHoMwSo] / (ρwHwMo) (15-1) As described above, N ₂ is the N measured by the bubble volume content measurement.
Therefore, the following relational expression is eventually obtained.

Sw = [ρwHwMo (N / N ₁ ) −ρoHoMwSo] / (ρwHwMo) (15-2) By the way, the γ-ray counting rate (= γ) measured by the γ-ray measurement system
The meaning of (line count value / measurement time) is as follows. Generally, γ-rays emitted from the γ-ray source 12 are scattered by the sample and change direction, so that the transmitted γ-ray intensity I (= γ-ray count rates G ₁ , G ₂ ) (c
pm) is represented by the following equation (16).

I = B · G · exp (−μρt) (16) where G: sample incident γ-ray intensity (cpm) μ: mass attenuation coefficient (cm ² / g) ρ: average density of the sample (g / g) cm ³ ) t: transmission path length (cm) B: build-up coefficient G is a constant defined by the radioactivity of the γ-ray source. The interaction between γ-rays and substances that attenuate incident γ-rays includes photoelectric effect, Compton scattering, and electron pair generation, and their reaction cross section (probability of interaction) depends on the energy of the substance and incident γ-rays. I do.

When Compton scattering is the main loss process, the mass attenuation coefficient μ in equation (16) is almost constant irrespective of the element. Therefore, in this measurement method, Compton scattering is the main energy loss process. A gamma ray having such energy is used.

Further, γ of the sample container 2 containing the sludge 1
Since there is no deformation in the direction of the light transmission path, t is constant, and γ
The transmission γ-ray count rate detected by the line detector 13 is an amount dependent on the sludge density ρ in the transmission path. That is, by measuring the transmitted γ-ray intensity I, the average density of the sludge 1 can be known. Since γ-rays emitted from the γ-ray source do not always have good directivity, an event occurs in which scattered γ-rays enter the γ-ray detector 13. This apparent transmitted γ-ray intensity I
Is corrected by the build-up coefficient B.

Incidentally, the sludge 1 under the condition of the first pressure P
Is in the relationship of the following equation (2). Sv + Sw + So + Sa = 1 (2) Now, γ-ray measurement under the condition of the first pressure P is considered.

The total thickness of one side of the sample container 2 and the pressure container 4 is h (cm), and the γ-ray transmission length in the sludge 1 is X (cm).
And Regarding the respective mass attenuation coefficients, air is μv (cm ² / g), water is μw (cm ² / g), organic matter is μo (cm ² / g), and inorganic matter is μa (cm ² / g).
g), and the container wall is set to μs (cm ² / g). For the respective densities, air is ρv (g / cm ³ ), water is ρW (g / cm ³ ), organic matter is ρo (g / cm ³ ), inorganic matter is ρa (g / cm ³ ), and the container wall is ρs (g / cm
³ ). Further, the number of gamma rays incident on the pressure vessel 4 is G
(Cpm), the number of transmitted γ-rays when the sample was sludge 1 was G ₂
Assuming that (cpm), from the relationship of Expression (16), G ₂ = BGＢexp ｛−μvρvSvX｝ · exp ｛−μwρwSwX｝ · exp ｛−μｏρoS
oX｝ · exp ｛-μaρSaX｝ · exp ｛-μsρs2
h｝ When the sample container 2 contains only air (that is, in an empty state), the number of transmitted γ-rays G ₁ (cpm) is given by: G ₁ = BG ＝ exp ・ -μvρvX ・ exp ｛-μs
ρs2h｝.

From these, G ₂ / G ₁ = exp ｛-μvρv (Sv-1) X｝ · exp ｛-μwρwSwX｝ · exp ｛-μoρoSoX｝ · exp ｛-μaρaSaX｝ Here, the mass attenuation coefficient does not depend on the substance. Since this is almost constant, μ (cm ² / g) = μv = μw = μo = μa This relationship is substituted, and the natural logarithm is obtained. In (G ₂ / G ₁ ) = − μρv (Sv−1) X −μρwSwX−μρoSoX−μρaSaX = −μX [ρv (Sv−1) −ρwSw−ρoSo−ρaSa] This is further transformed to ρvSv + ρwSw + ρoSo + ρaSa = [ln (G
₂ / G ₁ )] / (μX) + (2Sv−1) ρv Therefore, the average density ρ (g / cm ³ ) of the sludge is given by the following equation (1)
7).

ΡvSv + ρwSw + ρoSo + ρaSa = ρ (17) Accordingly, the average density ρ is obtained as in the following equation (18). ρ = [ln (G ₂ / G ₁ )] / (μX) + (2Sv−1) ρv (18) By the way, the following relational expression is established from the above description.

Sw = [ρwHwMo (N / N ₁ ) −ρoHoMwSo] / (ρwHwMo) (15-2) Sa = 1− (Sv + Sw + So) (from equation (2)) (19) ρ = ρvSv + ρwSw + ρoSo + ρaSa By substituting the equations (15-2) and (19) into the equation (17) and solving for So, the following equation (20) is obtained.

So = ρwHwMo [ρ−ρa + (ρa−ρv) Sv + (ρa−ρw) (N / N ₁ )] / [(ρo−ρa) ρwHwMo + (ρa−ρw) ρoHoMw] (20) Sw is obtained from equation (15-2) using the obtained So. Further, since So and Sw have been solved, Sa can also be solved. Thus, So, Sw, and Sa can all be determined.

In the above description, the first pressure P was assumed as the pressure condition, and the sludge component ratios So, Sw, and Sa at the first pressure P were determined. Similarly, assuming that the pressure condition is the second pressure P ₀ , the respective volume contents So ₀ , Sw ₀ , and Sa ₀ of the sludge component at the second pressure P ₀ can be obtained. In this case, in the description for obtaining So, Sw, and Sa, the first pressure P is set to the second pressure P ₀ ,
Sv is Sv ₀ , So is So ₀ , Sw is Sw ₀ , S
a may be replaced with Sa ₀ and N may be replaced with N ₀ .

In the method described above, the first method is used.
From the measured values under the condition of the pressure P and the condition of the second pressure P ₀ , the respective volume contents Sv and S of the sludge component under the first pressure P
w, So, and Sa were determined. However, from the following formula, from each volume content under the condition of the first pressure P, an arbitrary pressure P _{0 0}
The respective volume content of the sludge components below can also be determined.
It bubbles under a pressure P _{0 0,} water, organic substances, ₀ Sv ₀ each volume content of inorganic _{matter, Sw 0 0, So 0 0} , Sa 0 0
And

[0054] First, the bubble volume content Sv _{0 0} formula (8)
The following equation (21) is established from the relationship. Sv _{0 0} = SvP / P _{0 0} (21) Under the first pressure P, Vw + Vo + Va = (1 + m + n) Vw from the equations (3) and (4) by dividing both sides of the above equation by Ve and the following equation (22) And

[0055] Sw + So + Sa = (1 + m + n) Sw ... (22) in the pressure P _{0 0 Similarly, Vw 0 0 + Vo 0 0} + Va 0 0 = (1 + m + n) Vw 0
₀ Therefore, the following equation (23) is established.

Sw _{0 0} + So _{0 0} + Sa _{0 0} = (1 + m + n) Sw _{0 0} (23) Therefore, Sw _{0 0} / Sw is obtained from Expressions (22) and (23). Sw _{0 0} / Sw = erases Sv _{0 0} using _{(Sw 0 0 + So 0 0} + Sa 0 0) / (Sw + So + Sa) = (1-Sv 0 0) / (1-Sv) equation (21), further Sw _{0 0}
Is solved, the following equation (24) is obtained.

[0057] _{Sw 0 0 = Sw (P 0} 0 -PSv) / [P 0 0 (1-Sv)] ... (24) Similarly organics volume content So. _{0 0} also given by the following equation (25).

[0058] _{So 0 0 = So (P 0} 0 -PSv) / [P 0 0 (1-Sv)] ... (25) Finally, inorganic volume content Sa _{0 0} is determined by the following equation (26).

[0059] _{Sa 0 0 = 1-Sv 0} 0 -Sw 0 0 -So 0 0 ... (26) under the conditions of any pressure P _{0 0} from each volume content under the conditions of the thus first pressure P Can be obtained for each volume content.

[0060] obtained in the same manner a second pressure P each volume content Sv ₀ sludge under conditions of _{0, Sw 0, So 0,} Sa 0, under conditions of any pressure P _{0 0} Using this each volume content _{Sv 0 0, Sw 0 0,} So 0 0, Sa 0 0 can also be determined. In this case, equations (21), (24), (2)
In 5), P is P ₀ , Sv is Sv ₀ , and Sw is Sw
₀ and So may be read as So ₀ , respectively.

As described above, the pressure, the neutron count rate, and the γ-ray count rate are each measured, and the sludge is included in the sludge in a short time by calculating using the predetermined relational expression based on these measured values. The volume content of each component can be obtained. That is, the pressure applied to the sludge is divided into the first pressure P and the second pressure P.
Set in two conditions of pressure P _0, the respective pressure and neutron count rate is measured, also measures the γ-ray count rate at the time of either the first pressure P or the second pressure P _0. The two pressure values, the two neutron count rates, and the one γ-ray count rate, which are the measurement results, are calculated by an arithmetic processor using the arithmetic processing unit, and the bubble volume content, the water volume content, the organic matter volume content in the sludge, The inorganic volume content can be determined.

According to the above sludge component ratio measuring device, the neutron count rate and the γ-ray count rate are amounts that substantially depend only on the abundance ratio of specific atoms in the sludge. do not do. In addition, the reaction between neutrons and γ-rays and specific atoms is prompt, and the neutron detector and γ-ray detector measure the reaction results, so that the measurement time is short.

Next, in the apparatus of the above embodiment, ²⁵² Cf (radioisotope) was applied to the neutron source 10 and
^The case where the volume content of each component of the sludge 1 under atmospheric pressure is measured using ¹³⁷ Cs (radio isotope) will be described.

As described above, the volume contents Sv, Sw, So, and Sa of the bubbles, water, organic substances, and inorganic substances in the sludge 1 are described.
Sv = P ₀ (N ₀ −N) / (P ₀ N ₀ −PN) (12) So = ρwHwMo [ρ−ρa + (ρa−ρv) Sv (20) + (ρa−ρw) (N / N ₁ )] / [(ρo−ρa) ρwHwMo + (ρa−ρw) ρoHoMw] Sw = [ρwHwMo (N / N ₁ ) −ρoHoMwSo] / (ρwHwMo) (15-2) Sa = 1− (Sv + Sw + So) ) (19) ρ = [ln (G ₂ / G ₁ )] / (μX) + (2Sv−1) ρv (18)

In the above equation, N ₁ and G ₁ are constants required for calculation and need to be measured in advance. N ₁ is a neutron count rate when water is used as a sample, and G ₁ is a γ-ray count rate when water is used as a sample. This is input to the arithmetic processing unit 20 in advance as a constant.

A sample container 2 is filled with the collected sludge 1,
The component ratio is measured. First, the measurement of the bubble volume content is performed. The two pressure conditions are atmospheric pressure [P = 1 (atm)] and 5
The pressure was set to [P ₀ = 5 (atm)], and air was used as the pressure medium 6. The sample container 2 containing the sludge 1 is placed inside the pressure container 4, and first the neutron counting rate is measured under the condition of atmospheric pressure.

Fast neutrons emitted from ²⁵² Cf with an average of about 2 MeV are mainly scattered by hydrogen atoms in the sludge 1 and gradually lose energy. Eventually, thermal neutrons with very low energy are generated, and the neutron detector 11
As a result, the counting rate N
Get.

Next, the valve 9 is closed and the valve 8 is opened to supply compressed air from the pressure generator 5 to the pressure vessel 4. After the pressure sensor 4 confirms that the inside of the pressure vessel 4 is stabilized at 5 atm, the valve 8 is closed. At this time, a pressure of 5 atm is also applied to the sludge 1 inside the sample container 2. The bubbles contained in the sludge 1 decrease in volume according to the formula (8), but the sample container 2 responds to the volume change of the sludge 1 while applying the same pressure to the sludge 1 as the inside of the pressure container 4 by the action of the rubber film 3. . Further, since the side surface is made of stainless steel, the side surface portion is not deformed, and the neutron source 10 and the neutron detector 1 are not deformed.
1. The relative positional relationship between the sample containers 2 is kept constant. The neutron count rate is measured under the condition that 5 atm is added to the sludge 1, and the counter 18 obtains the count rate N ₀ . The measured P, P
₀ , N, and N ₀ are input to the arithmetic processor 20, and the bubble volume content Sv of the sludge 1 under the atmospheric pressure is calculated from the calculation based on the equation (12).

Further, the atmospheric pressure [P = 1
(Atm)], the γ-ray counting rate G ₂ is measured in advance. 0.66 MeV emitted from ¹³⁷ Cs
Most of the γ-rays having the above energy are scattered by the sludge 1 and change direction, but a part of the γ-rays is transmitted without being scattered and is incident on the γ-ray detector 13 and detected. In equation (18), as the mass attenuation coefficient μ, the main component of the sludge is water, so the mass attenuation coefficient of water with respect to γ-ray of 0.66 MeV is adopted, μ = 0.085 (cm ² / g), density As water: ρ
w = 1.0 (g / cm ³ ), organic matter: ρo = 1.5 (g
/ Cm ³ ), inorganics: ρa = 2.44 (g / cm ³ ),
Air: ρv = 1.293 × 10 ⁻³ (g / cm ³ ) is input to the arithmetic processor 20 in advance. Here, X is the γ-ray transmission path length in the sludge 1 and is an amount dependent on the sample container 2. The γ-ray counting rate G ₂ obtained from the counter 19 and the above-described Sv are input to the arithmetic processing unit 20, and the average density ρ (g / cm ³ ) is calculated from the equation (18).

The neutron count rate N obtained from the counter 18 measured to determine the bubble volume content rate, and Hw = 2, M
w = 18 (water molecular formula: from H ₂ O), organic substance is represented by cellulose (C ₆ H ₁₀ O ₅ ), and Ho = 10, Mo = 1.
62, using the above-described Sv and ρ, the arithmetic processor 20 calculates So, S from the equations (20), (15-2) and (19).
w and Sa are calculated.

In the first embodiment, the atmospheric pressure is adopted as one of the pressure conditions, and the volume contents of bubbles, organic substances, water and inorganic substances under the atmospheric pressure are determined. Various measured values are measured by the formulas, and finally, equations (21), (24),
Using (25) and (26), bubbles under atmospheric pressure, organic substances,
It is also possible to determine each volume content of water and inorganic substances.

In the first embodiment, the component ratio of the sludge 1 is calculated by using G ₁ and N ₁ measured in advance when calculating the volume content of the inorganic substance and the volume content of the organic substance (water). The sludge average density was determined in advance by determining the sludge average density and the calibration curve of G ₂ , and the organic matter (water) volume content rate and the N / N ₁ calibration curve were determined in advance to obtain the bubble volume content. The organic matter (water) volume content can also be obtained by performing correction according to the rate.

Further, as in the apparatus of the second embodiment shown in FIG.
The pressure generated by the pressure generator 24 may be transmitted to the sludge 21 by the pressure medium 25 while separating the sludge 21 and the pressure medium 25 by the piston mechanism. Also, partition 2
The pressure generated by the pressure generator 24 while separating the sludge 21 and the pressure medium 25 by fixing a rubber film inside the pressure vessel 22 also serving as a sample container instead of
1 may be transmitted.

Further, in the first embodiment, ²⁵² Cf was used as the neutron beam source 10, but instead of Am-
Other neutron sources such as Be may be used. Similarly, in the apparatus of the first embodiment, ¹³⁷ Cs was used as the γ-ray source 12.
Instead, another γ-ray source such as ¹⁹² Ir may be used.

FIG. 5 shows a conventional measurement method on the horizontal axis (comparative example).
FIG. 4 is a graph showing the correlation between the water volume content obtained by the method and the water volume content obtained by the measurement method (Example) of the present invention on the vertical axis.

FIG. 6 shows the conventional measuring method (comparative example) on the horizontal axis.
FIG. 5 is a graph showing the correlation between the organic substance volume content obtained by the method of Example 1 and the organic substance volume content obtained by the measurement method (Example) of the present invention on the vertical axis.

FIG. 7 shows the conventional measuring method (comparative example) on the horizontal axis.
FIG. 4 is a graph showing the correlation between the inorganic substance volume content obtained by the method of Example 1 and the vertical axis representing the inorganic volume content obtained by the measurement method (Example) of the present invention.

As is clear from FIGS. 5 to 7, the results of the examples have a strong correlation with the results of the comparative examples, and the measurement method of the present invention has high reliability and high accuracy. There was found.

[0079]

As described above in detail, the sludge component ratio measuring apparatus according to the present invention can measure the component ratio of sludge mixed with air bubbles in a short time. For this reason, in the sludge incineration equipment and the like, the component ratio of the input sludge can be fed back as appropriate as combustion control information of the incinerator. Therefore, by operating the furnace under always optimized conditions, the processing efficiency of the furnace is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a device for measuring a sludge component ratio according to a first embodiment of the present invention in a cut-away manner.

FIG. 2 is a schematic diagram for explaining a definition of a neutron counting rate for each sample.

FIG. 3 is a characteristic diagram for explaining the principle of measuring the water / organic substance volume content.

FIG. 4 is a block diagram schematically showing a sludge component ratio measuring device according to a second embodiment, with a cutout;

FIG. 5 is a graph showing the relationship between the water volume content obtained by a conventional measurement method and the water volume content obtained by the present measurement method.

FIG. 6 is a graph showing the relationship between the organic substance volume content obtained by a conventional measurement method and the organic substance volume content obtained by the present measurement method.

FIG. 7 is a graph showing the relationship between the volumetric content of an inorganic substance obtained by a conventional measuring method and the volumetric content of an inorganic substance obtained by the present measuring method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... sludge, 2 ... sample container, 3 ... rubber film, 4 ... pressure container (pressure-resistant container), 5 ... pressure generator, 6 ... pressure medium, 7 ... pressure sensor, 8, 9 ... valve, 10 ... neutron beam source , 11 ...
Neutron detector, 12: gamma ray source, 13: gamma ray detector, 14: preamplifier, 15: preamplifier, 16: wave height discriminator, 17: wave height discriminator, 18, 19: counter, 20
... arithmetic processor, 21 ... sludge, 22 ... sample container and pressure vessel, 23 ... partition wall, 24 ... pressure generator, 25 ... pressure medium,
26: pressure sensor, 27, 28: valve.

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shuro Inokawa 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. (72) Inventor Kiyoshi Uyama 61-1 Onocho, Tsurumi-ku, Yokohama-shi, Kanagawa JP-A-9-43170 (JP, A) JP-A-7-243994 (JP, A) JP-A-7-243995 (JP, A) JP-A-58-223039 (JP) JP, A) JP-A-61-71341 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 23/00-23/227 JICST file (JOIS)

Claims (6)

(57) [Claims] 1. A sludge component ratio measuring device for measuring the volume content of each of organic, inorganic, moisture, and air bubbles contained in sludge, comprising: (a) a pressure-resistant container containing sludge; b) a pressure applying means for applying an external pressure to the sludge accommodated in the pressure-resistant container, (c) an internal pressure measuring means for measuring the internal pressure of the pressure-resistant container, and (d) a neutron to the sludge accommodated in the pressure-resistant container. A neutron source for irradiation, and (e) a neutron detector for detecting neutrons scattered by the sludge;
(F) a neutron counting means for counting the count rate of detected scattered neutrons; (g) a gamma ray source for irradiating gamma rays to sludge in the pressure vessel from the outside; and (h) gamma rays for detecting gamma rays transmitted through the sludge. A detector; (i) gamma ray counting means for counting the count rate of detected transmitted gamma rays; (j) a plurality of neutron count rates counted under at least two different pressure conditions; Calculating means for determining the volume content of organic matter, inorganic matter, moisture, and bubbles contained in the sludge based on the gamma ray counting rate counted under any one of the pressure conditions. Component ratio measurement device. 2. The pressure-resistant container comprises a sample container for accommodating sludge, and an external container for storing the sample container therein, wherein the sample container is formed by a gas or a liquid as a pressure medium by the pressure applying means. Claims characterized by having a movable portion which is displaced or deformed so that an internal pressure and an external pressure become substantially the same when an external pressure is applied to generate an internal / external pressure difference, and a rigid portion which is not substantially displaced or deformed. Item 7. The sludge component ratio measuring device according to Item 1. 3. The sludge component according to claim 2, wherein each of the neutron source, the neutron detector, the gamma ray source, and the gamma ray detector is provided outside the outer container. Ratio measuring device. 4. The pressure-resistant container has a partition member for partitioning the inside into a sludge storage portion and a pressure application portion, and the partition member can change the internal volume in accordance with a change in the volume of the sludge. The sludge component ratio measuring device according to claim 1, wherein the pressure applied to the pressure application portion can be transmitted to the sludge. 5. The sludge component according to claim 4, wherein each of the neutron source, the neutron detector, the gamma ray source, and the gamma ray detector is provided outside the pressure-resistant container. Ratio measuring device. 6. A sludge component ratio measuring method for measuring a volume content of each component of organic matter, inorganic matter, moisture, and air bubbles contained in sludge, wherein (a) a first pressure P as a reference; The second different from this
The sludge is irradiated with neutrons under each condition of the pressure P ₀ , and the neutron counting rate N,
The N ₀ were measured, the ratio of these measurements (N ₀ / N)
Calculating the volume content rate Sv of bubbles contained in the sludge under the condition of the first pressure based on the following equation: Sv = P ₀ (N ₀ −N) / (P ₀ N ₀ −PN) ( b) irradiating the sludge with gamma rays under the condition of the first pressure P;
By measuring the count rate G ₂ of the gamma rays transmitted through the sludge, the measured gamma ray count rate G ₂ and the first pressure P
The ratio (G ₂ / G) of the gamma ray counting rate G ₁ and the gamma ray counting rate obtained for the sample containing only air under the condition of
₁ ) and calculating the average density ρ of the sludge based on the bubble volume content Sv using the following equation: ρ = [ln (G ₂ / G ₁ )] / (μX) + (2Sv−
1) ρv Here, μ represents a mass attenuation coefficient (cm ² / g), X represents a gamma ray transmission path length (cm), and ρv represents an air density (g / cm ³ ). (C) The ratio (N / N ₁ ) of the neutron count rate N measured under the condition of the first pressure P to the neutron count rate N _{1 of} only water previously determined under the condition of the first pressure P ), The average density ρ of the sludge, and the volume content Sv of the air bubbles, and calculating the volume content So of the organic matter contained in the sludge under the condition of the first pressure P using the following equation. And So = ρwHwMo [ρ−ρa + (ρa−ρv) Sv +
(Ρa−ρw) (N / N ₁ )] / [(ρo−ρa) ρw
HwMo + (ρa-ρw) ρoHoMw ] However, Rodaburyu the density of water (g / cm ^3), ρo is the density of the organic matter (g / cm ^3), ρa is the density of the inorganic (g / cm ^3), ρv is the air Density (g / cm ³ ), Hw represents the number of hydrogen atoms contained in one molecule of water, Ho represents the number of hydrogen atoms contained in one molecule of an organic substance, Mw represents the molecular weight of water, and Mo represents the molecular weight of the organic substance. (D) The ratio (N / N ₁ ) of the neutron count rate N measured under the condition of the first pressure P to the neutron count rate N _{1 of} only water previously determined under the condition of the first pressure P ) And calculating the volume content Sw of the water contained in the sludge under the condition of the first pressure P using the following equation based on the organic material volume content So: Sw = [ρwHwMo (N / N) ₁ ) -ρoHoMwS
o] / (ρwHwMo) (e) Sludge under the condition of the first pressure P using the following formula based on the bubble volume content Sv, the organic matter volume content So, and the water volume content Sw. A method for calculating a component ratio of sludge, comprising: a step of calculating a volume content Sa of an included inorganic substance; and Sa = 1− (Sv + Sw + So).