CN1282430C - Radiation type method and system for measuring filled value of cut tobacco - Google Patents

Abstract

The present invention relates to a method and a system for measuring the filling value of tobacco shreds by radiation. A gamma ray radioactive source and a gamma ray detector are correspondingly arranged above and under or under and above a conveyer belt, and a press roll type thickness measuring device is arranged above the conveyer belt in front of the gamma ray radioactive source. The output voltage UO of the gamma ray detector when no tobacco shred passes by is obtained by a signal output by the gamma ray detector. Tobacco shreds to be measured are arranged on the conveyer belt and pass through the press roll type thickness measuring device, the gamma ray radioactive source and the gamma ray detector successively; the output voltage Ui of the gamma ray detector when the tobacco shreds pressed by a press roll pass by the gamma ray detector is obtained by a signal output by the gamma ray detector, the thickness hi of the tobacco shreds is obtained by a signal output by the thickness measuring device, and the output signal is input to a control processor which is connected with the detector and the thickness measuring device for calculation processing. The filling value d of the tobacco shreds is calculated by the control processor according to the formula d=h/K[ln(Ui/UO)](1(+/-)delta), wherein the calibration factor K and the correction coefficient delta are obtained by calibrating true objects.

Description

A kind of method and system of actinometry tobacco fill value

Technical field

The present invention relates to grow tobacco a process technology and an equipment, relate in particular to a kind of method and system of measuring tobacco fill value.

Background technology

The filling value is that influence rolls one of key factor of quality cigarette, and when filling is worth when big, the cigarette that rolls is few with the pipe tobacco amount, and good permeability during cigarette combustion, the tar in the flue gas, nicotine and carbon monoxide content are also few, and mouthfeel is good; When filling value hour, the cigarette that rolls is many with the pipe tobacco amount, and gas permeability is poor during cigarette combustion, and the tar in the flue gas, nicotine and carbon monoxide content are also many, and mouthfeel is poor.Therefore in time measure the filling value of pipe tobacco, and control and produce the high pipe tobacco of filling value, the quality that improves cigarette is had significance.

The most methods that adopt timing sampling, static measurement of tobacco fill value are measured by each cigarette factory of China at present, and this far can not reflect timely and accurately, the filling value of pipe tobacco in actual production.Thereby the quality cigarette that rolls can not get guaranteeing

Have only Germany to produce online tobacco fill value measuring instrument at present in the world, it is to adopt three wide pressure rollers of 50mm to measure the thickness of pipe tobacco on the belt feeder, with the weight of pipe tobacco on the belted electronic balance measuring belt.Owing to measure the thickness that the pipe tobacco thickness of being pressed by three pressure rollers can not be represented pipe tobacco on the whole belt exactly, secondly, the weight of pipe tobacco is not the pipe tobacco weight that three pressure rollers were pressed on the whole belt that electronic scale claimed.Therefore, the tobacco fill value error that records with this measuring instrument is bigger.

When measuring the filling value of pipe tobacco with method of radiating, then requiring to measure the pipe tobacco weight that pressure roller was pressed, how to record these pipe tobacco weight that pressure roller was pressed, is a great problem that radiation method is measured tobacco fill value.Uclear scale metering pipe tobacco weight, the metering formula that adopts is F=Kln (U usually _i/ U ₀);

Weight of material (kg/m on the unit are on F-belt in the formula ²)

U ₀Gamma detector output voltage during-no material

U _i-gamma detector output voltage when material is arranged

K-calibration coefficient

At this, disturb together because the pipe tobacco that pipe tobacco and pressure roller on the belt were pressed is mixed, be difficult to separate, thereby the pipe tobacco weight of can't weighing pressing through pressure roller, just can't determine COEFFICIENT K with the gross weight method.Obviously, determine that COEFFICIENT K is the another difficult problem that radiation method is measured tobacco fill value.Though in the patent No. is to have proposed to weigh with radiation method in ZL 00 2 35663.5 patents, the unexposed method that how specifically to solve above-mentioned two problems.

In addition, because COEFFICIENT K and ln (U _i/ U ₀) be non-linear relation, the K value is influenced by the accumulation shape of material load variations, material, residing position and dispersion factor often will, how to describe the F and the ln (U that are subjected to above-mentioned four factor affecting _i/ U ₀) between variation relation, and come its variation relation of match by computation model, in order to improve the precision that the metering tobacco fill value is measured, this is again a difficult point anxious to be solved.

Summary of the invention

Technical problem to be solved by this invention provides a kind of method and system of actinometry tobacco fill value, and it can the automatic on-line measurement tobacco fill value, and the accuracy of measurement height, and good stability, reliability height, maintenance capacity are little.

To achieve these goals, the invention provides 1, a kind of method of actinometry tobacco fill value, comprise the steps:

Step 1, upper and lower or corresponding gamma-rays radioactive source and the gamma ray detector of being provided with of upper and lower side at transport tape, above the transport tape of the place ahead of gamma-rays radioactive source, the roller measuring thickness device is set, gamma ray detector output voltage U when passing through that the output signal by described gamma ray detector obtains no pipe tobacco ₀

Step 2 places pipe tobacco to be measured on the conveyer belt, successively successively by described pressure roller measuring thickness device, gamma-rays radioactive source and gamma ray detector; Output voltage U when the pipe tobacco that obtains to be pressed by pressure roller by described gamma ray detector passes through gamma ray detector _i, and the thickness h that obtains described pipe tobacco by the output signal of described measuring thickness device _i, described output signal is input to the control processor that is connected with described measuring thickness device with described detector carries out calculation process;

Step 3, described control processor carries out computing by following data processing model, obtains tobacco fill value d:

d＝h/K[ln(U _i/U ₀)] ^(1±δ)

Wherein, COEFFICIENT K δ is by known tobacco fill value d ₀Pipe tobacco demarcate, determine.

The method of above-mentioned actinometry tobacco fill value, its characteristics are that in step 3, when δ=0, calibration coefficient K is d with known filling value ₀Pipe tobacco demarcate, determine K=K ₀, described control processor is according to the h that records _i, and utilize d=h _i/ K ₀[ln (U _i/ U ₀)] formula carries out computing, thereby realize on-line automatic measurement tobacco fill value d ₀

The method of above-mentioned actinometry tobacco fill value, its characteristics be, in step 3, and δ=-constant between 0.2-+0.2, calibration coefficient K is with known tobacco fill value d ₀Pipe tobacco demarcate, determine calibration coefficient K;

Described control processor is according to the pipe tobacco thickness h that records _iAnd utilize open

D=h/K ₀[ln (U _i/ U ₀)] ^{(1 ± δ)}Carry out computing, thereby realize on-line automatic measurement tobacco fill value d.

The method of above-mentioned actinometry tobacco fill value, its characteristics are that correction factor K is by known tobacco fill value d ₀Pipe tobacco demarcate, revise definite, and the pipe tobacco thickness that further records according to described measuring thickness device is by K _i=f (h _i) variation relation dynamically revises, and obtains revised dynamic calibration COEFFICIENT K _f

Described control processor is according to described dynamic calibration COEFFICIENT K _f, and utilize

D=h _i/ K _f[ln (U _i/ U ₀)] ^{(1 ± δ)}Thereby carry out computing and realize on-line automatic measurement tobacco fill value d.

The method of above-mentioned actinometry tobacco fill value, its characteristics are that described calibration coefficient K and pipe tobacco thickness are pressed K _i=f (h _i) variation relation obtains as follows: with known identical tobacco fill value d ₀Pipe tobacco, at different-thickness h ₁, h ₂H _iUnder the situation, COEFFICIENT K is demarcated the corresponding K that obtains ₁, K ₂K _i, further obtain K _i=f (h _i) the variation relation curve, obtain K with curve-fitting method again _i=f (h _i) variation relation, and with described K _i=f (h _i) variation relation deposits the control processor in.

The method of above-mentioned actinometry tobacco fill value, its characteristics are, described known tobacco fill value d ₀Be meant the tobacco fill value of measuring with static measurement method.

The method of above-mentioned actinometry tobacco fill value, its characteristics be, the center line of described radioactive source and detector is parallel to each other and in a plane, described plane and described transport tape handing-over line and described pressure roller pressed the center line of tobacco stream to coincide.

The method of above-mentioned actinometry tobacco fill value, its characteristics are, the barricade that has through hole in the middle of is set above described detector, and described gamma-rays can shine the ray sensitive volume of described detector by described through hole; The width D of described through hole≤pressure roller width D ₁, the length of the length L of described through hole≤described ray sensitive volume.

The method of above-mentioned actinometry tobacco fill value, its characteristics are that it is preceding through shaping that described pipe tobacco enters pressure roller.

In order to realize that better above-mentioned order has, the present invention also provides a kind of tobacco fill value measuring system of utilizing the described method of claim 1 to make, comprise rack-mount gamma ray radiator, gamma ray radiator detector, roller measuring thickness device, transport tape, control processor, described control processor connects described radioactive source detector and roller measuring thickness device respectively, and the pressure roller of described roller measuring thickness device is arranged on the place ahead of described transport tape top and described gamma ray radiator; Its characteristics are,

Described control processor is used for carrying out computing according to following data processing model, obtains tobacco fill value d:d=h/k[ln (U _i/ U ₀)] ^{(1 ± δ)}

Wherein, U ₀Gamma ray detector output voltage when passing through for no pipe tobacco;

U _iOutput voltage when passing through gamma ray detector for the pipe tobacco of being pressed by pressure roller;

H is the thickness of the pipe tobacco of being pressed by pressure roller;

K is a calibration coefficient;

δ is a correction factor.

Above-mentioned system, its characteristics are, the center line of described radioactive source and detector is parallel to each other and in a plane, described plane is perpendicular to described transport tape, and the center line of the tobacco stream that described plane and described transport tape handing-over line and described pressure roller were pressed coincides.

Above-mentioned system, its characteristics are, the barricade that has through hole in the middle of is set above described detector, and described gamma-rays can shine in the ray sensitive volume of described detector by described through hole.

Above-mentioned system, its characteristics are, the width D of described through hole≤pressure roller width D ₁, the length of the length L of described through hole≤described ray sensitive volume.

Above-mentioned system, its characteristics are that the area of described through hole is adjustable.

Above-mentioned system, its characteristics are that described pressure roller is for pressing a plurality of pressure rollers arranged in a straight line, and last pressure roller connects the linear grating displacement transducer.

Above-mentioned system, its characteristics are, the roller measuring thickness device comprises pressure roller, slide block, guide rail, linear grating displacement transducer, described pressure roller is installed on the described slide block, described guide rail is connected to described linear grating displacement transducer, and described slide block and linear grating displacement transducer are installed in the described guide rail.

Above-mentioned system, its characteristics are that described pressure roller is the spinning pressure roller, and the tangential motion direction of described pressure roller when the contact pipe tobacco is consistent with the transport tape moving direction.

Above-mentioned system, its characteristics are, also are provided with a pipe tobacco shaping feed bin before described roller measuring thickness device.

Above-mentioned system, its characteristics are that the gamma-rays radioactive source adopts ²⁴¹Am line source or point source, gamma ray detector adopt thin-wall chamber or proportional counter tube or G-M pipe or NaI scintillation counter, or plastic scintillant.

Adopt said method and system, solved the problems of the prior art, can the automatic on-line measurement tobacco fill value, and the accuracy of measurement height, good stability, reliability height, maintenance capacity are little.

Further specify specific embodiments of the invention below in conjunction with accompanying drawing

Description of drawings

Fig. 1 is the system that tobacco fill value is measured in first kind of radiation shown in the present automatically

Fig. 1 a is an A-A view among Fig. 1

Fig. 2 is the system that tobacco fill value is measured in second kind of radiation shown in the present automatically

Fig. 2 a is the enlarged drawing at I place among Fig. 2

Fig. 3 is the front view of barricade among Fig. 1 and Fig. 2

Fig. 3 a is the side view of Fig. 3

Fig. 4 is the schematic diagram of measurement mechanism among Fig. 1

Fig. 4 a is the cutaway view at A-A place among Fig. 4

Fig. 5 is the system that tobacco fill value is measured in the third radiation shown in the present automatically

Fig. 5 a is the schematic diagram of measurement mechanism among Fig. 5

Fig. 5 b is the cutaway view at B-B place among Fig. 5 a

Fig. 6 is that control system of the present invention is according to the h that records _iThe block diagram that k is dynamically revised

Wherein, accompanying drawing marking explanation:

1-controls processor, 2-gamma ray detector, 21-ionisation chamber collector, 22-ionisation chamber high-pressure stage, the 3-barricade, 4-pressure roller, 5-connecting rod, the 51-bolster, 5 '-slide block, 6-guide rail, the 7-angular displacement sensor, 7 '-linear displacement transducer, 8-pipe tobacco, the 9-radioactive source, 10-support, the last belt of 11-, the 12-screw rod, 12a-adjusts nut, 20-shell.

The specific embodiment

In Fig. 1, the present invention only provides the pipe tobacco weight that pressure roller was pressed in order to make radioactive source 9 and gamma ray detector 2, radioactive source 9 and gamma ray detector 2 are installed in last belt 11 upper and lower of belt feeder, and place the back of pressure roller 4, the center line of radioactive source 9 and gamma ray detector 2 is parallel to each other, and in a plane, the center line of the tobacco stream that the handing-over line of this plane and last belt should be pressed with pressure roller 4 coincides.

Secondly, be equipped with gamma ray shielding plate 3 above gamma ray detector 2, have the wide D that is on it, length is the oblong aperture of L.Here D and L adapt with the length of the gamma-rays sensitive volume of the width of pressure roller 4 and gamma ray detector 2 respectively, to guarantee to measure exactly pipe tobacco 8 weight that pressure roller 4 was pressed.

The present invention proposes a kind of Mathematical Modeling of measuring tobacco fill value:

The graduated cylinder that the method for static measurement filling value is is 60mm with a column type diameter, be scattered in the 20g pipe tobacco (containing moisture about 12.5%) of tested tobacco fill value in the graduated cylinder equably, the last survey piece of exerting pressure of pressing 3 kilograms, continue after 30 seconds, read the height of pipe tobacco, just can obtain the filling value of pipe tobacco.

d＝πr ².h/m……①

In the formula: d---tobacco fill value, cm ³/ g;

R---survey the radius of tube, cm;

The height of pipe tobacco behind h-pressurized, cm;

The quality of m---pipe tobacco, g

Measure tobacco fill value with Radiation Measurements, suppose:

The volume that V-pipe tobacco occupies

The weight of W-pipe tobacco

Belt speed is υ _i, the pressure roller width D is at t _iThe pipe tobacco average thickness that calibrator is measured in second is h _i, then the pipe tobacco volume by pressure roller is

Vi＝D·υ _i·t _i·h _i

At t in second, the pipe tobacco weight W that radiation detector provides _i=F υ _iT _iD,

Because of F=K[ln (U _i/ U ₀)] ^{(1 ± δ)}So, W _i=K[ln (U _i/ U ₀)] υ _iT _iD

According to formula 1.

d＝V/W＝(D·υ _i·t _i.·h _i)/{K[ln(U _i/U ₀)] ^(1±δ)·υ _i·t _i·D}＝h _i/{K[ln(U _i/U ₀)] ^(1±δ)} --②

In the formula: h _iThe pipe tobacco thickness that-calibrator is measured

U ₀Gamma detector output voltage during-no material

U _i-gamma detector output voltage when material is arranged

K-calibration coefficient

δ-correction factor.

2. formula is exactly the present invention measures tobacco fill value with radiation method Mathematical Modeling.

COEFFICIENT K in the above-mentioned formula and δ with known tobacco fill value (measuring) with static measurement method through materials calibration, correction and definite.Filling value scaling method is exactly: earlier with the COEFFICIENT K that configures ₁Be input to computer with δ, will have a certain amount of, same filling value d again ₀Pipe tobacco feeding conveyer, by a plurality of pressure rollers 4 and gamma ray detector 2, this computer-chronograph is d=h/K by formula ₁[ln (U _i/ U ₀)] ^{(1 ± δ)}, to tobacco fill value measure d ₁, then use d again ₀And d ₁To K ₁Revise with δ, by that analogy, repeated multiple times is until K _iOr δ satisfies error=[(d ₀-d _i)/d ₀] till the 100%≤desired error.

Owing to measure the Mathematical Modeling d=h of filling value _i/ K[ln (U _i/ U ₀)] ^{(1 ± δ)}K in the formula, δ value difference so it has multiple expression-form, are specifically described as follows:

Embodiment 1:

Used Mathematical Modeling d=h _i/ K[ln (U _i/ U ₀)] ^{(1 ± δ)}, establishing δ=0 in the formula, calibration coefficient K is the d of known filling value ₀Pipe tobacco is demarcated, and determines K=K ₀, concrete steps are as follows:

Establish K earlier ₁=20, and the input computer, treat that the conveyer blanking bar has moved 3 minutes, records V ₀=4.35, record the average filling value d of pipe tobacco with static method ₀Be 4.5cm ³The pipe tobacco of/g feeding conveyer, and making by pressure roller and detector, computer acquisition this moment be from measuring thickness device signal and detector signal, and in second, measure pipe tobacco average height h at t ₁=4.88cm, the output voltage signal mean value U of detector ₁=4.1V, last, computer calculates tobacco fill value

d ₁=h _i/ K ₁[ln (U _i/ U ₀)]=4.12cm ³/ g, then,

Use d ₀=4.5cm ³/ g, d ₁=4.12cm ³/ g and K ₁=20 couples of K revise,

Obtain K ₂=K ₁* d ₁/ d ₀=18.342;

With K ₂The input computer is again with d ₀=4.5cm ³The pipe tobacco feeding conveyer of/g, and make it by pressure roller and detector, computer acquisition this moment signal in second, draws pipe tobacco average height h at t ₂Be 4.83cm, the detector output voltage average value is U ₂=4.102V, computer calculate tobacco fill value d ₂=4.485, at this moment, according to error formula

The time, demarcation finishes.

If error does not satisfy requirement, as stated above, continue K is revised, till meeting the demands.At last, the correction value to K0 is K0=18.342.

In when metering, control system is according to the hi that records, by formula: di=hi/[18.342*ln (Ui/U0)] obtain tobacco fill value.

Embodiment 2

Used Mathematical Modeling is: d=hi/K[ln (Ui/U0)] (1 ± δ), δ is-a certain constant between 0.2-+0.2 in the formula, the K value is that the pipe tobacco with known tobacco fill value d0 carries out repeatedly materials calibration, comprehensively determines K and δ value, specifically as embodiment 1, determine K=18.342, δ is-0.0116, control system according to the hi that records by formula:

D=h _i/ K[ln (U _i/ U ₀)] ^{(1 ± δ)}=h _i/ 18.342*[ln (U _i/ U ₀)] ^1.0116, obtain the filling value.

Embodiment 3

Used Mathematical Modeling d=h _i/ K[ln (U _i/ U ₀)] ^{(1 ± δ)}, establishing δ in the formula and be a certain constant between 0-0.2, K is the pipe tobacco thickness function, i.e. K=f (h _i).

In enforcement of the present invention, because pipe tobacco thickness difference on the belt 11, so the dispersion factor influence is also different, thereby can not be considered as constant with K, so must obtain the pipe tobacco thickness h _iWith COEFFICIENT K _iBetween variation relation, its method is: with the pipe tobacco of known identical d value, at different-thickness h ₁, h ₂H _iUnder the situation, COEFFICIENT K is demarcated, obtain K accordingly ₁, K ₂K _i, obtain h _iWith K _iThe variation relation curve, obtain h with curve-fitting method again _iAnd K _iBetween variation relation, and deposit computer control system 1 in.When tobacco fill value is measured, according to the pipe tobacco thickness h that records _iTo K _iRevise.

The concrete operations step is as follows:

Step 1, with known filling value d ₀Pipe tobacco coefficient k is revised

Treat conveyer blanking bar operation 3 minutes, record U ₀=4.35V; Record the average filling value d of pipe tobacco with static method ₀Be 4.5cm ³/ g; Elder generation's bidding is decided coefficient k ₁=20 and δ=0, and the input computer, be d with tobacco fill value again ₀=4.5cm ³The pipe tobacco of/g feeding conveyer, and make it by pressure roller and detector, this computer-chronograph is gathered from calibrator signal and detector signal, and at t in second, measuring the pipe tobacco average height is h ₁=4.88cm, the output voltage signal mean value of detector is U ₁=4.1V, last, the tobacco fill value that computer records $d$ $1=\frac{h1}{\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="C20031012180200181.png"\; state="\{\{state\}\}">k</figure-callout>}1\mathrm{Ln}\frac{U1}{U0}}=\frac{4.88}{20\mathrm{Ln}\frac{4.1}{4.35}}=\frac{4.88}{20\&times;0.05919}=4.126$

Then, use d ₀=4.5cm ³/ g, d ₁=4.126cm ³/ g and k ₁=20 couples of k revise, $\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="C20031012180200181.png"\; state="\{\{state\}\}">k</figure-callout>}2=\frac{d1}{d0}\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="C20031012180200181.png"\; state="\{\{state\}\}">k</figure-callout>}1=\frac{4.126}{4.5}\&times;20=18.342;$ With k ₂Import computer again, again with d ₀=4.5 pipe tobacco feeding conveyer, and make it by pressure roller and detector, this computer-chronograph is gathered signal, draws pipe tobacco average height h in second at t ₂Be 4.83cm, the detector output voltage average value is U ₂=4.102V, last, computer records tobacco fill value $d$ $2=\frac{h2}{\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="C20031012180200181.png"\; state="\{\{state\}\}">k</figure-callout>}2\mathrm{Ln}\frac{U2}{U0}}=\frac{4.83}{18.342\mathrm{Ln}\frac{4.102}{4.35}}=\frac{4.83}{18.342\&times;0.05871}=4.485$

Error The time, demarcation finishes.Do not satisfy requirement as error, as stated above, continue k is revised, till meeting the demands.

Step 2 is asked h ₁..., h _iWith k ₁..., k _iVariation relation

Found first point: the h in the above in (step 1) ₁=4.83 o'clock, k ₁=18.342, still use known d ₀=4.5 pipe tobacco is at h ₂＞h ₁Give the conveyer feeding during a certain Metacentre Height, by pressure roller and detector, this computer-chronograph carries out signals collecting, in time second, records average h at t ₂=6.32cm, the detector output voltage U ₂=4.02V, computer calculates $\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="C20031012180200181.png"\; state="\{\{state\}\}">d</figure-callout>}2=\frac{h2}{\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="C20031012180200181.png"\; state="\{\{state\}\}">k</figure-callout>}1\mathrm{Ln}\frac{U2}{U0}}=\frac{6.32}{18.342\mathrm{<figure-callout\; id="4"\; label="Ln"\; filenames="C20031012180200221.png,C20031012180200222.png"\; state="\{\{state\}\}">Ln</figure-callout>}\frac{4.02}{4.35}}=\frac{6.32}{18.342\&times;0.07889}=4.367,$ Then use d ₀=4.5 and d ₂=4.367 and k ₁=18.342 couples of k revise, and obtain $\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="C20031012180200181.png"\; state="\{\{state\}\}">k</figure-callout>}2=\frac{d2}{d0}\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="C20031012180200181.png"\; state="\{\{state\}\}">k</figure-callout>}1=\frac{4.367}{4.5}\&times;18.342=17.79,$ Obtain h thus _iAnd k _iBetween second point, h ₂=6.32cm, k ₂=17.79;

By that analogy, use the same method and obtain thirdly: h ₃=7.8, k ₃=17.13, U _iMean value be 3.931; The 4th point: h ₄=9.4, k ₄=16.21, U _iMean value be 3.824 or the like.Can get h thus _iAnd k _iBetween variation relation.Above-mentioned data list is as follows:

With k _iBe ordinate, h _iFor abscissa draws a little 1,2,3,4, connect 1-2,2-3, each line of 3-4 has just been obtained h _iAnd k _iRelation curve.

From relation curve, be not difficult to draw, at h ₂And h _iBetween the equation of change formula of k value be

$\mathrm{ki}=k1-\frac{k1-k2}{h2-\mathrm{hi}}\&times;(\mathrm{hi}-h1)=18.342-\frac{18.342-17.79}{6.32-4.83}\&times;(\mathrm{hi}-4.83)---\left(a\right)$

At h ₂And h ₃Between, k value equation of change formula is:

$\mathrm{ki}=k2-\frac{k2-k3}{h3-h2}(\mathrm{hi}-h2)=17.79-\frac{17.79-17.13}{7.8-6.32}\&times;(\mathrm{hi}-6.32)---\left(b\right)$

K value equation of change formula is between h3 and h4:

$\mathrm{ki}=k3-\frac{k3-k4}{h4-h3}(\mathrm{hi}-h3)=17.13-\frac{17.13-16.21}{9.4-7.8}(\mathrm{hi}-7.8)---\left(c\right)$

When metering, the pipe tobacco height that requires to be fed remains on h ₁-h ₄Between change.Control system is according to the h that records _iBy step shown in Figure 6 k is revised.

By formula at last $\mathrm{di}=\frac{\mathrm{hi}}{\mathrm{kiLn}\frac{\mathrm{Ui}}{U0}}$ Obtain tobacco fill value.

Among the embodiment 1,2,3, all adopt Fig. 1, Fig. 1 a, Fig. 3, Fig. 4, Fig. 4 a and tobacco fill value measuring system shown in Figure 5.This system mainly contains radiation weighing device (containing radioactive source 9, gamma ray detector 2, barricade 3), multi roll pipe tobacco measuring thickness device (containing a plurality of pressure rollers 4, connecting rod 5, back shaft 51, angular displacement sensor 7), computer control system 1 and compositions such as support 10 and shell 20.The output signal of gamma ray detector 2 and angular displacement sensor 7 is connected with computer control system 1 by cable.Radioactive source 9 is installed on shell 20 top boards, gamma ray detector 2 is fixed on the negative of shell 20, barricade 3 is installed in the top of gamma ray detector 2, and measuring thickness device is installed in the place ahead of gamma ray detector 2, and a plurality of pressure rollers 4 of measuring thickness device are contacted with last belt 11.

This system's main feature:

(1) gamma-rays radioactive source 9 and gamma ray detector 2 are installed in the upper and lower of belt 11 on the conveyer respectively, and both center lines are consistent with last belt 11 traffic directions; Barricade 3 is installed in the top of gamma ray detector 9; A plurality of pressure rollers 4 of measuring thickness device are installed in radiation weighing device the place ahead and contact with last belt 11, require the center line of gamma-rays radioactive source 9 and gamma ray detector 2 to be parallel to each other again, and in a plane, the center line of the tobacco stream that this plane and belt intersecting lens and a plurality of pressure roller 4 were pressed coincides.

(2) gamma-rays radioactive source 9 adopts ²⁴¹The Am radioactive source, gamma ray detector 2 adopts proportional counter tube.

(3) measuring thickness device adopts the multi roll measuring thickness device, and it is made up of a plurality of pressure rollers 4, connecting rod 5, back shaft 51, angular displacement sensor 7 and fixed support 10.The connecting rod 5 of pressure roller 4 links to each other with angular displacement sensor 7, and the purpose that adopts a plurality of pressure rollers 5 is to make pipe tobacco 8 be subjected to the pressure of certain duration.

(4) barricade 3 has oblong aperture, and the gamma-rays sensitive length of bore size and pressure roller 4 width and gamma ray detector 3 adapts, and can guarantee accurately to measure the weight of being pressed pipe tobacco.With double nut 12a with barricade 3 be installed in be fixed on shell 20 top boards or four screw rods 12 on the base plate on, and the adjustable shield plate is to the distance between radioactive source or the detector.

(5) displacement transducer is optional with raster pattern or magnetic-grid-type sensor.

(6) control system can be selected PLC or Industry Control PC for use.

In Fig. 5, Fig. 5 a and Fig. 5 b, another embodiment of the present invention: radioactive source 9 adopts ²⁴¹Am line source, length are 300mm, intensity 100-150 millicurie, and gamma ray detector 2 adopts the thin-wall chamber, and its sensitive length is 600mm; It is 6mm that barricade 3 adopts thickness, longly is 1000mm, and wide is the iron plate of 200mm, has oblong aperture (55mm * 600mm) therebetween; The pressure roller 4 of measuring thickness device is stainless steel φ 100mm, wide 50mm, the pressure that its weight should satisfy static measurement filling value requires displacement measuring device to comprise pressure roller 4, slide block 5 ', guide rail 6, linear displacement transducer 7 ', wherein linear displacement transducer 7 ' adopts linear grating formula displacement transducer or angle displacement sensor 7; The control treatment system adopts PLC.

Another embodiment of the present invention:

Adopt ²⁴¹The Am point source, intensity 100-150 millicurie, gamma ray detector 2 adopt φ 55mm NaI scintillation crystal; The iron plate that barricade 3 adopts 100mm * 100mm, centre to open the circular hole of Φ 50mm, other are identical with preceding scheme.

In addition, implement better in order to make such scheme, can also be provided with spinning mechanism on pressure roller 4, allow pressure roller rotation when belt moves, play heap because of pressure roller 4 is obstructed to prevent pipe tobacco on belt, influence is measured.Spinning mechanism can drive pressure roller by a micro motor is set.

With advancing; on belt, play heap in order to reduce pipe tobacco as far as possible; in the present embodiment; one shaping also can be set at feed bin bin gate place presses when making pipe tobacco feeding belt through a shaping pressure roller; pipe tobacco is pressed the more smooth shape of formation; this helps to measure pressure roller work, and the protection pipe tobacco does not play heap when running into the measurement pressure roller.

Useful effect of the present invention

(1) calibrator can accurately be measured the thickness of pipe tobacco; The radiation weighing device can accurately be measured Gu the pipe tobacco weight of pressing through pressure roller is and the accuracy of measurement height of native system.

(2) native system is measured and is controlled pipe tobacco filling value in real time, guarantees to roll the quality of cigarette.

(3) native system adopts the radiation weight method, and this method is contactless weighing, it have good stability, The advantages such as reliability height, a little repair.

Claims (19)

1, a kind of method of actinometry tobacco fill value comprises the steps:

Step 1, upper and lower or corresponding gamma-rays radioactive source and the gamma ray detector of being provided with of upper and lower side at transport tape, above the transport tape of the place ahead of gamma-rays radioactive source, the roller measuring thickness device is set, gamma ray detector output voltage U when passing through that the output signal by described gamma ray detector obtains no pipe tobacco ₀

Step 2 places pipe tobacco to be measured on the conveyer belt, successively successively by described pressure roller measuring thickness device, gamma-rays radioactive source and gamma ray detector; Output voltage U when the pipe tobacco that obtains to be pressed by pressure roller by described gamma ray detector passes through gamma ray detector _i, and the thickness h that obtains described pipe tobacco by the output signal of described measuring thickness device _i, described output signal is input to the control processor that is connected with described measuring thickness device with described detector carries out calculation process;

Step 3, described control processor carries out computing by following data processing model, obtains tobacco fill value d:

d＝h/K[ln(U _i/U ₀)] ^(1±δ)

Wherein, COEFFICIENT K, δ are by known tobacco fill value d ₀Pipe tobacco demarcate, determine.

2, the method for actinometry tobacco fill value according to claim 1 is characterized in that, in step 3, when δ=0, calibration coefficient K is d with known filling value ₀Pipe tobacco demarcate, determine K=K ₀, described control processor is according to the h that records _i, and utilize d=h _i/ K ₀[ln (U _i/ U ₀)] formula carries out computing, thereby realize on-line automatic measurement tobacco fill value d ₀

3, the method for actinometry tobacco fill value according to claim 1 is characterized in that, in step 3, and δ=-constant between 0.2-+0.2, calibration coefficient K is with known tobacco fill value d ₀Pipe tobacco demarcate, determine calibration coefficient K;

Described control processor is according to the pipe tobacco thickness h that records _iAnd utilize open

D=h/K ₀[ln (U _i/ U ₀)] ^{(1 ± δ)}Carry out computing, thereby realize on-line automatic measurement tobacco fill value d.

According to the method for claim 2 or 3 described actinometry tobacco fill value, it is characterized in that 4, correction factor K is by known tobacco fill value d ₀Pipe tobacco demarcate, revise definite, and the pipe tobacco thickness that further records according to described measuring thickness device is by K _i=f (h _i) variation relation dynamically revises, and obtains revised dynamic calibration COEFFICIENT K _f

Described control processor is according to described dynamic calibration COEFFICIENT K _f, and utilize

D=h _i/ K _f[ln (U _i/ U ₀)] ^{(1 ± δ)}Thereby carry out computing and realize on-line automatic measurement tobacco fill value d.

5, the method for actinometry tobacco fill value according to claim 4 is characterized in that, described calibration coefficient K and pipe tobacco thickness are pressed K _i=f (h _i) variation relation obtains as follows: with known identical tobacco fill value d ₀Pipe tobacco, at different-thickness h ₁, h ₂H _iUnder the situation, COEFFICIENT K is demarcated the corresponding K that obtains ₁, K ₂K _i, further obtain K _i=f (h _i) the variation relation curve, obtain K with curve-fitting method again _i=f (h _i) variation relation, and with described K _i=f (h _i) variation relation deposits the control processor in.

6, according to the method for claim 1,2,3 or 5 described actinometry tobacco fill value, it is characterized in that described known tobacco fill value d ₀Be meant the tobacco fill value of measuring with static measurement method.

7, the method for actinometry tobacco fill value according to claim 1, it is characterized in that, the center line of described radioactive source and detector is parallel to each other and in a plane, described plane and described transport tape handing-over line and described pressure roller pressed the center line of tobacco stream to coincide.

According to the method for claim 1 or 7 described actinometry tobacco fill value, it is characterized in that 8, the barricade that has through hole in the middle of is set, and described gamma-rays can shine the ray sensitive volume of described detector by described through hole above described detector; The width D of described through hole≤pressure roller width D ₁, the length of the length L of described through hole≤described ray sensitive volume.

9, the method for actinometry tobacco fill value according to claim 1 is characterized in that, it is preceding through shaping that described pipe tobacco enters pressure roller.

10, a kind of tobacco fill value measuring system of utilizing the described method of claim 1 to make, comprise rack-mount gamma ray radiator, gamma ray radiator detector, roller measuring thickness device, transport tape, control processor, described control processor connects described radioactive source detector and roller measuring thickness device respectively, and the pressure roller of described roller measuring thickness device is arranged on the place ahead of described transport tape top and described gamma ray radiator; It is characterized in that,

Described control processor is used for carrying out computing according to following data processing model, obtains tobacco fill value d:d=h/k[ln (U _i/ U ₀)] ^{(1 ± δ)}

Wherein, U ₀Gamma ray detector output voltage when passing through for no pipe tobacco;

U _iOutput voltage when passing through gamma ray detector for the pipe tobacco of being pressed by pressure roller;

H is the thickness of the pipe tobacco of being pressed by pressure roller;

K is a calibration coefficient;

δ is a correction factor.

11, system according to claim 10, it is characterized in that, the center line of described radioactive source and detector is parallel to each other and in a plane, described plane is perpendicular to described transport tape, and the center line of the tobacco stream that described plane and described transport tape handing-over line and described pressure roller were pressed coincides.

According to claim 10 or 11 described systems, it is characterized in that 12, the barricade that has through hole in the middle of is set, and described gamma-rays can shine in the ray sensitive volume of described detector by described through hole above described detector.

13, system according to claim 12 is characterized in that, the width D of described through hole≤pressure roller width D ₁The length of the length L of described through hole≤described ray sensitive volume.

14, system according to claim 12 is characterized in that, the area of described through hole is adjustable.

15, system according to claim 10 is characterized in that, described pressure roller is for pressing a plurality of pressure rollers arranged in a straight line, and last pressure roller connects the linear grating displacement transducer.

16, according to claim 10 or 15 described systems, it is characterized in that, the roller measuring thickness device comprises pressure roller, slide block, guide rail, linear grating displacement transducer, described pressure roller is installed on the described slide block, described guide rail is connected to described linear grating displacement transducer, and described slide block and linear grating displacement transducer are installed in the described guide rail.

According to claim 10 or 15 described systems, it is characterized in that 17, described pressure roller is the spinning pressure roller, the tangential motion direction of described pressure roller when the contact pipe tobacco is consistent with the transport tape moving direction.

18, system according to claim 10 is characterized in that, also is provided with a pipe tobacco shaping feed bin before described roller measuring thickness device.

19, system according to claim 10 is characterized in that, the gamma-rays radioactive source adopts ²⁴¹Am line source or point source, gamma ray detector adopt thin-wall chamber or proportional counter tube or G-M pipe or NaI scintillation counter, or plastic scintillant.

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