CN1063162A

CN1063162A - Method for detecting measured value and measuring device thereof

Info

Publication number: CN1063162A
Application number: CN91112787A
Authority: CN
Inventors: H·伯舍
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-12-06
Filing date: 1991-12-06
Publication date: 1992-07-29
Anticipated expiration: 2006-12-06
Also published as: TW226438B; WO1992010745A1; JPH05504411A; CN1029530C; FI923537L; ZA919595B; BR9106215A; FI923537A7; EP0514531A1; DE4038994C2; MX9102404A; AU8914591A; CA2075034A1; DE4038994A1; FI923537A0

Abstract

For detecting whether a partially or substantially completely emptied container has been contaminated with an impermissible substance, for example a plastic bottle containing mineral water, has been used for preserving a plant protection agent at the user. During detection, a gas sample drawn from a container is ionized by a discharge gap (3) and its discharge characteristic (U) is measured_F) And/or the gas ionization rate as a relevant measurement.

Description

Detect the method and the measuring equipment thereof of measured value

The present invention relates to a kind of usefulness and will carry out the mode of ionization, the method that the measured value relevant with the gas in container sky or that part is empty detected, and a kind of measuring equipment of this method of application from the gas of container.

By each description partly that in the EP-A-0306307 description of the invention it is combined into one as can be known, in the field that container utilizes again, need particularly resemble the plastic containers of plastic bottle one class, whether have pollution in the detection receptacle the container of sky.

For this reason, this invention suggestion utilizes ionization technique, and for example flame ionization in ultraviolet ray range or photoionization technology detect described pollution, and might before can again contaminated container be rejected whereby.And, think that here ultraviolet ionize has bigger superiority.

Consider, particularly when online detection, need a large amount of containers be detected rapidly and directly one by one, and based on the consideration of reliability, this detection method must be as far as possible simply and efficiently.

By the disclosed method of EP-A-0306307, promptly extracting gases sample from each container carries out flame ionization to carry out the method for final analysis to it, is a kind of slow method, and considers it also is disadvantageous from the simplification aspect.Because it must make when using hydrogen flame to carry out flame ionization, by the gas of flame by-pass flow flame is not produced tangible influence, speed that gas stream crosses and the detection speed that determines therefrom are restricted.In addition, employed flame gas is quite expensive.

The at first disclosed and ionization technique preferentially selected for use of suggestion needs to utilize ultraviolet ray by EP-A-0306307, and this makes this technical sophisticationization.Find out among the embodiment that this point can be provided by above-mentioned EP file.Adopt this ionization technique, must clean ionization device continually.And wherein requisite UV-lamp is also quite expensive.But it still advises preferentially selecting for use ultraviolet ionize technology.

The purpose of this invention is to provide a kind of detection method that can overcome by the above-mentioned shortcoming of the employed technology of EP-A-0306307.

In general, method and apparatus of the present invention is:

A kind of method that the measured value relevant with the gas in container sky or that part is empty detected, this method comprises carries out ionization to the described gas in the container, it is characterized in that detected container carrying on the interference-free production line basically, described gas is exposed on the discharge gap (3), and the discharge characteristic (U of described discharge gap _F) and/or gas ionization rate (i) detect as measured value.

A kind of checkout equipment that is used for detecting the gas ingredients of the container of on production line, carrying, this equipment has and container is taken to or away from the conveying device of measurement mechanism, have the gas ionization device on the measurement mechanism, it is characterized in that ionization device comprise at least one can with the contacted discharge gap of gas of drawing in the container.

Therefore, above-mentioned purpose can realize.

The shape in this discharge of electricity crack can be similar to, such as, the ignition spark plug of internal combustion engine.Because it is very little that it can be done, vulnerable to pollution and structure are not flexible, in fact can be by powering to it Anywhere, so it is simple especially.

By using discharge gap to make the technology of gas ionization, be exactly known for a long time, for example referring to United States Patent (USP) 2550498(1951), relate to the United States Patent (USP) 3728615(1973 that cigarette detects), relate to the United States Patent (USP) 4629992(1986 that fire detects) etc. 々.But in these are used, the kind 々 advantage of carrying out ionization because of electron discharge as reliable cleaning and 々 such as preparation once more fast, is unessential during gas sample is carried out ionization, in an application of the invention, importantly how rapid and continuous conveying.

According to preferred forms of the present invention, this conveying of carrying out that can be very fast.This is because it does not rely on gas flow speed basically, but also because under certain user mode, the present invention is different with flame ionization, it can also be put among the vessel.

By seeing in the disclosed prior art of EP-A-0306307, this prior art has significant disadvantages aspect reliable, be that it can only measure the total ion concentration that forms on the ionization basis, and can not provide the ion which kind it includes thus.

When using method of the present invention, if being carried out ionization, gas also further measuring-signal is detected, just can detect the ion that whether has some particular types according to the activity of the ion that in described gas, occurs.

As mentioned above, the present invention has other ions of known activity level detect existing or do not exist, and has obtained useful combination the between simple and dexterous insertion body and higher suction force.

To by means of accompanying drawing the present invention be further detailed from different angles below.

Fig. 1 shows the example that utilizes a discharge gap to carry out ionization and the minimum effective measured value relevant with a certain container of selecting detected in real time of the present invention.

Fig. 2 shows another variant embodiment based on equipment shown in Figure 1, in this embodiment, is that discharge current is controlled and utilized the characteristic parameter of control loop to detect above-mentioned measured value.

Fig. 3 shows an example that is used in the discharge gap that carries out gas ionization in the container of the present invention.

Fig. 4 shows first variant embodiment that the electrostatic ionic precipitation separation device that utilizes gas discharge ionization and set up detects measured value.

Fig. 5 shows the further remodeling of equipment shown in Figure 4, in this embodiment, is that a precipitation separation relevant with the activity of various different ions detects as measured value.

Fig. 6 shows the internal state of an examined container, and wherein, a spark ionization device is connected with an ion isolation settler that carries out the active selection work of static.

Fig. 7 shows the example that the promising preselector that prevents the blast of some polluters and establish is set, and wherein, discharge gap is positioned within (a) container or (b) outside the container.

Fig. 8 shows an example of checkout equipment of the present invention, and it comprises the transmitting device and the gas suction device that are used for transmission container on production line, and the pick-up unit of the present invention that is connected in series with discharge gap.

As previously mentioned, problem involved in the present invention mainly is empty to be carried out the detection of pollutional condition, such as the plastic bottle that those preparations of carrying at production line are re-used detects. These containers from the 々 such as initial can mineral water, fruit juice after turned letter again the utilization, its storage configuration is very uncertain. Know at present, this bottle, such as in the family, normal 々 is used for other purposes, such as being used for the 々 such as long-term splendid attire suds, plant protection product, motor oil, acid, alcohol, gasoline. If deposited these materials in the container, when so container being sent to again can with re-using, just need to consider whether the polluter of certain kind can be to the again taste generation infringement of the former can thing of can, perhaps whether container can further cause indigestion because being subjected to polluting, even unwholesome situation takes place, if so, just can not be directly used in again can.

Therefore, must whether also have and have which residual contamination material in the inspection instrument, in order to can not be used for again carrying out to those container of again can Normal juice, such as those should at first carry out the container of special cleaning, and those can carry out selecting between the container of again can to process really.

Can also be further to container, plastic bottle particularly, container material on some on Polluter detect, these polluters may be absorbed by its inner-wall material and discharge in the material of again can slow 々.

Fig. 1 shows first variant embodiment of the equipment that is used to detect measured value.It has following meaning at least, and promptly it can detect in the gas in electrical condenser whether have the pollution that some determines substance classes.In some cases,, will make the gas above it also contaminated, so the container that method of the present invention also can be used for to can detects because the can thing in the container is polluted.

For detect empty or partly can, the container of type as described in Figure 8, can be by being arranged in the suction tube 1 outside the container that Fig. 1 do not illustrate, extract out in the container or with container in the can thing be the gas sample G of direct contact condition, and this gas is delivered to discharge gap 3 places with electrode pair 5.Make discharge gap 3 discharges by means of power supply 7.This discharge can produce with the form of corona discharge or spark discharge.

By the aspirator that does not illustrate among Fig. 1, tested gas sample G sucking-off and deliver to discharge gap 3 from electrical condenser can be changed its sparking voltage thus.This voltage U _FCan measure by voltmeter 11.

The output signal of voltage 11 as the detected measured value signal of need, and is sent it into comparing unit 13, and this comparing unit 13 also receives the reference signal of being sent here by reference signal unit 15.Comparing unit 13 is according to sparking voltage U _FSelect to detect, and provide the output signal A of relevant measured value ₁, A ₂...These signals are relevant with some specific pollutants matter mixture or some completely specified polluter, but also can be relevant with specific pollution concentration.Reference signal can be set by canonical measure, and can proofread and correct according to the dusty gas sample of standard.

Fig. 2 shows another variant embodiment of equipment shown in Figure 1, and it also can be used for the measured value of discharge gap 3 of the present invention is detected.Here, be to make by a controllable high-voltage source 7a to keep discharge between two electrodes 5 of discharge gap 3.Measure discharge current i with galvanometer 11a _F, and the demarcation current reference value i that this electric current and reference signal unit 19 is provided with comparing unit 17 _FSOLLCompare.

Difference signal △ with comparing unit 17 obtains if necessary, can be used as and transfers difference to send into controller 21, and with the regulated quantity that the regulating loop in this current control circuit is exported, send into controllable voltage source 7a, like this, and discharge current i _FJust can follow the tracks of the controlled reference value that the derived reference signal 19 as the calibration value generator provides.In preferred forms, this value should with constant demarcation reference value i _SOLLMatch.

Act on the accent difference signal △ and/or the conditioning signal S of the output voltage of voltage source and/or this voltage source 7a _U, also can be used as measured value and it detected.Can be as described in Figure 1, the comparing unit 13 that the input of these measured values is connected with reference unit 15, and can be as required, range of signal by control circuit detects measured value, can infer thus in tested gas sample G whether have some pollution of planting material or the concentration of its pollution.

Shown in Fig. 1 and Fig. 2, the flash-over characteristic of discharge gap 3 and to its electric control makes this discharge gap itself can directly be used as the measured value receiver of measured value.

In embodiment illustrated in figures 1 and 2, the discharge of generation can be corona direct current or alternating current discharge.

As illustrated in figs. 1 and 2, the gas sample that extracts from examined container passes suction tube 1.

Therefore, can form structure shown in Figure 3 fully, promptly only discharge gap 3 further be dwindled, by means of, such as, test suction pipe 23 shown in Figure 3, discharge gap 3 put into examined container 25, in container 25, start discharge gap 3, carry out subsequent treatment by embodiment illustrated in figures 1 and 2 then.

In Fig. 3, the tap 27 on the suction pipe 23 corresponding among Fig. 1 and Fig. 2 with the output terminal of the described discharge gap 3 of identical reference number 27 expressions.

Fig. 4 shows another embodiment of equipment of the present invention.This embodiment also be by means of discharge gap with gas ionization, but with Fig. 1 and Fig. 2 different be that this embodiment detects the ionization gas that leaves discharge gap.

In this embodiment, be by suction tube 1 in container or with container in extracting gases sample G the gas that directly contacts of can thing, gas sample was sent the discharge gap 3 that starts by current source 7.The downstream of the discharge gap 3 on gas flow direction is provided with a capacitive means.This capacitive means is, such as, a garden cylindrical condenser 29, it is made up of garden cylindricality external capacitive body shell 29a and the interior axle 29i coaxial with it.

By 29 chargings of 31 pairs of capacitors of variable voltage source, make it reach predetermined magnitude of voltage, thereby in capacitor, set up electric field E.Because gas is ionized at discharge gap 3 places, so according to polarity and the intensity of electric field E, the ion of a kind of polarity in the gas will be driven into a pole plate among two capacitor plate 29a, the 29i, and the ion of another kind of polarity is driven and is moved on to another pole plate.Capacitor plate 29a, 29i be in order to form balance with the ion that is driven on capacitor plate 29a, the 29i, will with foreign current loop that garden cylindrical condenser as the ion isolation settling vessel is connected in produce current i.This electric current can be used as integration current and is measured by charge amplifier 32, also can be measured by current amplifier 32a shown in dotted line.

If use charge amplifier 32, should pre-determine T integral time, and in this time, carry out integration pass the electric current that capacitor 29 produced because of gas.Therefore, this time interval T should determine that signal ST starts timing by random top measuring period.This signal ST can with, such as bleed beginning or a certain definite wavefront of current i occur relevant.

After integral time, T finished, the reset switch in the charge amplifier 32 shown in Figure 4 will be closed.

If output signal be by charge amplifier 32 output corresponding to the signal of integration current or by the similar signal of current amplifier 32a output, then this output signal can be imported comparing unit 13 in the described mode of Fig. 1, determines output signal A by the latter according to the size of the input signal E that is produced ₁, A ₂... Deng 々, and provide the signal relevant with measured value at its output terminal.

And, shown in Figure 4 when being arranged in the structure of suction tube 1 when adopting, can also with according to the set discharge gap 3 of the present invention as shown in Figure 3, be placed on one and examined in the container, examined gas is carried out ionization.

Since miniaturization the structure of dexterity of discharge gap, make and to carry out gas ionization with selected equipment in place arbitrarily, and precipitation separation can carry out in same place, promptly or suction tube or examined container in carry out, also can carry out in the place that partly is separated with ionization.

In the described testing process of Fig. 4, only 々 detects the relevant measured value of total gas charge balance that forms on the basis of spark ionization.Fig. 5 shows a kind of better in principle embodiment, and promptly the direction along suction tube 1 sets gradually several capacitors 29, and makes gas with certain gas stream strength speed input.Adopt this structure, the gas ionization that can utilize arrester of the present invention to draw from container earlier, according to ionic activity the ion that produces in the gas is detected then, produce certain different materials or some the kind material that pollutes thereby can selectively detect.

Here, be with Ionized gas G ^*Introduced electrostatic precipitation step 35 same as shown in Figure 4 basically.This electrostatic separation precipitation step, such as still constitute by garden column capacitance apparatus.Such as it has one to pass several and be provided with continuously and the interior axle 30i that stretches of garden cylindrical surface 30a insulated from each other.Each capacitor by axle 30i and each garden cylindrical surface 30a in same constitute all at first carries out same electrostatic charging with voltage source 31, so that make each capacitor 30i, 30a have equal field intensity E.

As shown in the figure, the gas that carries the ion with different activities enters capacitor chamber 30, and is subjected to the effect of even field intensity E therein.Suppose that ionic charge is identical, biasing force is also identical, is then in axial direction going up, and the distance that the weak ion of the ion ratio activity of active strong (energy is strong) moves is farther.Therefore, the current i of drawing from each capacitor as measured value ₁, i ₂..., relevant with the amount of the ion that departs from this direction on gas flow direction successively, even ion is active less, bigger for the electric current that produces on that part of capacitive means of upstream side on the gas flow direction.

The current i of drawing is passable, as shown in Figure 4, is detected by charge amplifier or current amplifier, and handles successively as the measured value that container is selected.

Fig. 6 shows a kind of embodiment that gas discharge ionization and electrostatic separation are measured that directly carries out in container.This embodiment is the further remodeling to equipment shown in Figure 3, promptly is provided with in the upper area of suction pipe 23 of discharge gap 3 at its end, is provided with the metal surface 33i that a multistage type insulate each other, and the metal garden cylindrical surface 33a of a coaxial setting.

As shown in the figure, this further suction pipe of remodeling can be put into and examined container, and at its bottom section, gas is by discharge gap 3 ionization.Then, the gas of internal tank forms the air-flow that flows to vessel port and will pass suction pipe because of being heated, and this of having retrofited at suction pipe is provided with the precipitation separation level that is formed by several capacitors 33i, 33a in partly.

And, preferably spray into other gas, to oppress ionized gas G by as shown in the figure opening 37 ^*Form air-flow.

Be used for the charging circuit of arrester 3 and capacitor device and be used for current i ₁, i ₂々 such as electric current follower Deng the tap of 々 all can draw by suction pipe 23, and the pipeline that is used for gas discharge outlet 37 also is like this.

As mentioned above, to variant embodiment shown in Figure 3, best mode is to form corona discharge at Fig. 1.In Fig. 4 to Fig. 6, among the embodiment shown in any figure, not only can adopt corona discharge, but also can adopt spark discharge, make gas sample ionization.When adopting spark discharge, for measuring, best mode is to make it produce continuous a certain amount of spark in air-flow, utilizes ionized gas G ^*Measure its ion concentration and preset time is averaged, to obtain testing result accurately.

For some polluter,, may set off an explosion if use discharge ionization of the present invention or known flame ionization.Thereby, must before using ionization technique, carry out preliminary election to the container that transports from the security standpoint consideration.This point can solve by the detection to container shown in Fig. 7 a.It is the container that resembles plastic bottle one class that will detect, and takes first detection position 40 to by the transfer equipment of travelling belt or rotation transmission device one class.In this detection position in a known manner, promptly directly put into cell therefor, the polluter with explosion danger is detected by the extracting gases sample or with sensor.

Preferably, select suitable semiconductor gas sensor or electrochemical cell for use here, according to the detected polluter that explosion danger is arranged.As shown in the figure,, can pass through, such as the mode of breakout box is carried in control, and cell therefor is rejected from the container that will further detect detected container with explosion danger pollutants.With the container of above-mentioned danger can not take place accordingly, deliver to ionization measuring position 42 with suction pipe 23.

Other pollution is being detected and on the basis that 44 pairs of relevant with it measuring-signals of detecting unit detect, controlling another and carry breakout box, thereby underproof contaminated container is picked out or carried out special cleaning.Only 々 is when its pollution is within the allowed band, and this contaminated container just can be transferred out to carry out can once more.

As preceding described, some container, such as plastic bottle particularly can be absorbed with some polluter on its wall material, and can slow 々 it is discharged in the inner chamber of container.If do not having under the situation of extraordinary precaution, the pollution concentration in a certain definite time point detection receptacle is difficult to it is detected.Thereby the can again of this container meeting quilt, and long-term storage, thereby can produce lasting infringement to the taste of can thing.

Therefore, the present invention further advises adopting following manner, promptly shown in 46, before carrying out pollution detection, the polluter that absorbs on the chamber wall is discharged in Fig. 7.In the present invention, by being heated, container realizes this point.Can with shown in thermal source Q carry out infrared radiation, and, also be specially adapted to microwave heating for plastic containers.Can also be by container intracavity and/or outside being carried out evaporation and stifling, and realize this point with feeding hot conventional gas.

Though not explanation in some cases, can be used gas above, preferably air carries out purge to container, and preferably some residual gas composition purges that derive from some original can thing should be fallen, otherwise they may cover in the residual contamination material when carrying out pollution detection.

Shown in Fig. 7 b, the gas sample G of Chou Quing from container ^*, before gas sample being sent into discharge ionization or flame ionization unit 41, be that the polluter of explosion danger detects at first to whether existing in the gas sample that extracts.41 the front in the unit can be provided with a positioner, such as, a valve 45 is set.

In a preferred variation embodiment as shown in Figure 8, be to utilize the vector gas from vector gas jar 70, draw, extract detected gas the container 71 from conveyer 72, for example use by the sharp suction tube of the venturi of end cover 74 and extract.The vector gas that utilizes pump 76 will be loaded with container gas is input to the measurement mechanism 78 with discharge gap.By reversal valve V _GS, can be with bridge formation mode cross-over connection container, but also can be with pure quiet vector gas, for example pure dead air carries out purge to installing 78.

Claims

1, a kind of method that the measured value relevant with the gas in container sky or that part is empty detected, this method comprises carries out ionization to the described gas in the container, it is characterized in that detected container carrying on the interference-free production line basically, described gas is exposed to discharge gap (3), and the flash-over characteristic parameter (U of described discharge gap _F) and/or gas ionization rate (i) detect as measured value.

2,, it is characterized in that detecting with described gas ionization and to the measuring-signal relevant with the activity of different ions in the gas according to the method for claim 1.

3,, it is characterized in that using the mode that ionized gas is carried out static electronics precipitation separation that measured value is detected according to the method for claim 1 or 2.

4,, it is characterized in that obtaining measured value with the mode that has the electrostatic ionic precipitation separation level of different predetermined lengths and the ion isolation rate of deposition on each precipitation separation level is detected is set according to the method for claim 3.

5, according to the method for claim 1, it is characterized in that carrying out before the discharge examination, in advance described gas is carried out selectivity and detect, so that the gas that explosion danger is arranged is not carried out discharge examination.

6, according to the method for claim 1-5, it is characterized in that before the measured value that generation is used to detect, usefulness, such as water, steam, gas, preferably air cleans container.

7,, it is characterized in that before the measured value that generation is used to detect usefulness, such as infrared illumination source, steam, water, gas, preferably air or microwave energy heats container according to the method for claim 1-6.

8,, it is characterized in that producing described discharge with the form of corona discharge or spark discharge according to the method for claim 1-7.

9,, it is characterized in that making the gas of drawing from container to flow through from discharge gap according to the method for claim 1-8.

10,, it is characterized in that producing continuously spark discharge according to the method for claim 1-9.

11,, it is characterized in that the ionization state that is formed by predetermined a series of sparks in the gas is detected according to the method for claim 10.

12,, it is characterized in that discharging and in container, carry out according to the method for claim 1-11.

13,, it is characterized in that the gas in the container is carried out measured value to be detected according to the method for claim 12.

14,, it is characterized in that discharging and carry out at external container according to the method for claim 1.

15,, it is characterized in that difference or its corresponding sparking voltage or discharge current are controlled and exchanged to discharge current or sparking voltage to be measured according to the method for claim 1-14.

16, a kind of checkout equipment that is used for detecting the gas componant of the container of on production line, carrying, this equipment have with the container band to or away from the conveying device of measurement mechanism, measurement mechanism is provided with the gas ionization device, it is characterized in that ionization device comprise at least one can with the contacted discharge gap of gas of drawing in the container.

17,, it is characterized in that discharge gap is by discharge current or sparking voltage control according to the checkout equipment of claim 16.

18,, it is characterized in that discharge gap is connected with an electrostatic ionic precipitation separation level at least according to the checkout equipment of claim 16.

19,, it is characterized in that discharge gap is arranged on the container that can put on the conveyer and the suction tube that can take out from container according to the checkout equipment of claim 16-18.

20,, it is characterized in that upstream side at discharge gap is provided with one and is used for from being positioned at the device of the container extracting gases sample on the conveying device according to the checkout equipment of claim 16-19.

21, according to the checkout equipment of claim 16-20, it is characterized in that being provided with the selecting arrangement that is positioned at the discharge gap upstream side, this selecting arrangement detects the gas ingredients that whether has explosion danger in the gas, and prevention has the gas of explosion danger to contact with discharge gap.

22, the equipment of the method for utilization claim 1-15 and claim 16-21 carries out the selectivity processing to the container of sending to can again.

23, according to the purposes of claim 22, the plastic bottle of adorning food is carried out selectivity handle.