Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
  • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
  • G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
  • G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
  • G01N21/359—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light using near infrared light
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N15/00—Investigating characteristics of particles; Investigating permeability, pore-volume or surface-area of porous materials
  • G01N15/02—Investigating particle size or size distribution
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
  • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
  • G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
  • G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
  • G01N21/3563—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing solids; Preparation of samples therefor
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/84—Systems specially adapted for particular applications
  • G01N21/85—Investigating moving fluids or granular solids
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
  • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
  • G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
  • G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
  • G01N21/35—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light
  • G01N21/3577—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using infrared light for analysing liquids, e.g. polluted water

Definitions

• the present invention relates to an apparatus for examin ⁇ ing a flowable material.
• near-infra-red spectroscopy is used to designate methods of measurements based upon the inter- action between matter and electromagnetic radiation in the wavelength range from 700 to 2500 nm.
• the reason for using this expression is that it refers to the part of the infra-red wavelength range lying closest to the visual range of the spectrum (400 to 700 nm) .
• the expression “near-near-infra-red range” is used for electromagnetic radiation with wavelengths from 700 to 1200 nm.
• Near-infra-red spectroscopy is used for determining com- ponents of various materials, e.g. in meat products.
• Meat consists substantially of water, protein and fat.
• the cause of the absorption is that two different atoms being bonded to each other func ⁇ tion in the manner of an electric dipole taking energy from the electric and magnetic fields in the radiation, making the group of atoms concerned vibrate.
• Measurements in the near-infra-red range may be carried out in two ways, either by passing light through the sample (near-infra-red transmission, NIT) or based on the reflection from the surface of the sample (near-infra ⁇ red reflection, NIR) .
• NIT near-infra-red transmission
• NIR near-infra ⁇ red reflection
• Various analysis apparatus for examining materials by means of NIT spectroscopy are known.
• One of these ap ⁇ paratuses comprises a number of cups, in which a homoge ⁇ nized sample is placed. Then, the absorption of the sample is measured at a number of different wavelengths, and the content of components is computed on the basis of the absorption values having been found.
• the apparatus is extremely complicated to use. Thus, it is necessary to take a sample that is representative of the material to be examined, then the sample has to be homogenized, and finally the homogenized material has to be placed in the cups of the apparatus using great care. After this, the analysis-may be carried out.
• the object of the present invention to provide an apparatus for examining a flowable material, with which it is possible to exploit the advantages associated with spectroscopy, but which is not so complicated to use as the previously known apparatus referred to above.
• the apparatus according to the invention should operate automatically without the need for the preparatory work referred to above (manual taking of a representative sample quantity, preparing a homogenized sample and pla ⁇ cing in cups) .
• the apparatus according to the present invention is characterized by comprising a tube having an opening for receiving material and an opening for discharging material as well as a tube segment adapted for making measurements, a measuring device placed ad ⁇ jacent said tube segment and having a light source on one side of the tube segment to transmit light into the segment and a light receiver on the opposite side of the segment to measure the effect upon the light of a material placed in the segment, the walls of the tube segment comprising the beam path between the light source and the light receiver being made of a material that is trans ⁇ lucent or transparent for the wavelength range of the light to be examined, and a recording unit connected to said measuring device and adapted to record individual measurement values or sets of same for material having been placed in said tube segment.
• the sample there is no requirement for the sample to be liquid or homogeneous, such as is the case with the previously known apparatus. It is only required that the sample be flowable, so that it can pass through a tube. In this connection, the taking of samples and the analysis of the material can be carried out automatically, also in those cases, in which the sample is inhomogeneous. For this reason, the apparatus does not require operators skilled in taking a sample of the material or judging whether a sample quantity is representative. It is only necessary to dimension the measuring equipment for rela- tively small sizes of samples, as the sampling and meas ⁇ uring is merely repeated, until the sum total of the measurements is representative and provides the desired accuracy of measurement.
• the mechanical parts may be small, and it is still possible to adjust the total volume of material being measured to what is optimum or desired in each case.
• the NIT analysis described it has been found possible with the NIT analysis described to carry out measurements on relatively large quantities of an inhomogeneous material for each measuring cycle, so that a limited number of measurements may be sufficient and the method hence also becoming practically useful for making measurements on unprocessed and inhomogeneous materials.
• the content of components in the material may be monitored continuously by automatic and repeated analysis of new samples. This makes it possible to use the apparatus according to the invention for determining the moment in time, at which a material possesses a requisite property, e.g. uniformity with regard to components.
• Plants already having been installed in establishments for the production and/or processing of various materials can be made to give an increased yield when supplemented with an analysis apparatus according to the present in ⁇ vention.
• the apparatus according to the present invention may be used in connection with flowable materials, whether these be in the form of particles or liquids. It is especially advantageous to use the apparatus in connection with non-uniform material, e.g. consisting of components of different compositions, because the apparatus does not require the samples to be homogenized in order to achieve reliable results.
• the apparatus is especially useful for examining foodstuffs, fodder and pharmaceutical materials.
• Such materials may e.g. include: - vegetable foods, such a wheat, barley, rye, maize, rice, coffee and cocoa in the form of whole grains or a ground or comminuted product (analysis for protein, starch, carbohydrate and/or water) , seeds, e.g. peas and beans, such as soy beans (analysis for protein, fats and/or water) , products mainly consisting of or extracted from vegetable raw mate ⁇ rials, such as snacks, dough, vegetable mixtures, margarine, edible oils, fibre products, chocolate, sugar, syrup, lozenges and dried coffee extract (powder/granulate) ,
• - animal foodstuffs such as dairy produce, e.g. milk, yoghurt and other soured milk products, ice cream, cheese (analysis for protein, carbohydrate, lactose, fat and/or water) , meat products, e.g. meat of pork, beef, mutton, poultry and fish in the form of minced or emulgated products (analysis for protein, fat, water and/or salts) and eggs, which foodstuffs may be present in a completely or partly frozen condition, - fodder, e.g. pellets or dry/wet fodder mixtures of vegetable products, fats and protein-containing raw materials, including pet food,
• dairy produce e.g. milk, yoghurt and other soured milk products, ice cream, cheese
• meat products e.g. meat of pork, beef, mutton, poultry and fish in the form of minced or emulgated products
• minced or emulgated products analysis for protein, fat, water and/or salts
• - pharmaceutical products such as tablets, mixtures, creams and ointments, and - technical substances, e.g. wet and dry mixtures of cement and mortar, plastics, e.g. in granular form, mineral materials, such as solvents and petro ⁇ chemical products, e.g. oils, hydrocarbons and as- phalt, solutions of organic or inorganic substan ⁇ ces, e.g. sugar solutions.
• the material being present in the tube segment during a measurement may constitute a quantity that is not repre- sentative for the determination of one or a number of components of a greater quantity of material, from which the sample has been taken, e.g. a mixing tank or tub. If it is required, the content of one or a number of com ⁇ ponents in such a larger quantity of material may be determined by repeating the measuring procedure so many times with new material being introduced in the tube segment, that the sum total of the quantities of material being measured in the tube section constitutes a repre ⁇ sentative quantity.
• the tube segment may e.g. be inserted in a tube through which the material flows, or in a branch or loop on such a tube.
• the apparatus preferably operates with a non-destructive sampling and analysis, in which the sample material is returned or advanced in an unharmed state.
• a non-destructive sampling and analysis in which the sample material is returned or advanced in an unharmed state.
• the steps of taking samples from a tank or tub, a tube or the like, introducing samples having been taken into the tube segment, and measuring the effect of the material on light, are preferably carried out whilst the material is in movement, as this may contribute to a correct samp ⁇ ling.
• the following materials may be used:
• Si A very sensitive and cheap detector type, useful in the range from 400 to 1100 nm.
• Ge Hardly as sensitive as Si, but is useful from
• InGaAs Only half as sensitive as Si, but reacts very quickly and is useful from 800 to 1760 nm.
• PbS Low sensitivity, but is cheap and is useful from 650 to 3000 nm. Temperature stabilization is required.
• PMT Photo-Multiplier Tube
• An embodiment of the apparatus according to the invention consists in that the measuring device is adapted to meas ⁇ ure the effect of the material upon light in the near- infra-red interval, preferably transmission of near-infra ⁇ red light (NIT) through a material being placed in said tube segment.
• NIT near-infra ⁇ red light
• the measuring device is adapted to measure the transmittance or absorbance of a material placed in said tube segment at a number of wavelengths in the range from 700 to 2400 nm, preferably 10 or more wavelengths, especially in the near-near-infra-red interval from 700 to 1200 nm.
• the content of one or a number of components of the material can be determined on the basis of the measurement values or sets of same having been recorded. It has been found that NIT measurements may also be used for determining the particle size of the material in the tube.
• the transmittance or absorb- ance of a particulate material placed in said tube segment may be measured at a number of wavelengths in the range from 700 to 2400 nm, especially 700 to 1200 nm, after which the particle size of the material can be determined on the basis of the measurement values or sets of same having been recorded.
• the measurement values may be used for adjusting the composition of a greater quantity of material.
• the content of one or a number of components of samples of the mate ⁇ rial is determined on the basis of the recorded measure ⁇ ment values or sets of same, and the results or their deviation from desired values or information about neces ⁇ sary addition of a component to the bulk of material in order to achieve a desired value is shown on a display and/or used for controlling a dosing unit adapted to make up for the deficiency of a component, e.g. by adding the requisite quantity to the bulk of material in a mixing tank.
• the apparatus according to the present invention may be adapted to measure the transmittance or absorbance of a particulate material, e.g. a minced or cut meat product with an average particle size of between 2 and 30 mm at a number of wavelengths in the near-infra-red range, pre ⁇ ferably between 700 and 1200 nm, and to use recorded measurement values or sets of same
• a particulate material e.g. a minced or cut meat product with an average particle size of between 2 and 30 mm at a number of wavelengths in the near-infra-red range, pre ⁇ ferably between 700 and 1200 nm
• a meat product for determining the content of one or a number of components of the material, e.g. in a meat product, preferably its content of fat, protein, collagen and/or water,
• the tube and the measuring device are con- structed and dimensioned in such a manner, that the volume of the material being subjected to measurements is greater than 20 cm 3 , preferably greater than 50 cm 3 and particu ⁇ larly greater than 100 cm 3 .
• the fluctuations in the measurements caused by inhomogeneities in the components and/or particle size of the material will be reduced.
• meas ⁇ uring volumes it is in some cases possible to carry out the measurements directly on a material stream in produc ⁇ tion, so that taking of samples as such may be avoided.
• the tube is dimensioned in such a manner, that the path length of the light rays through the mate ⁇ rial exceeds 25 mm, preferably lying between 40 and 100 mm.
• the path length of the light rays through the mate ⁇ rial exceeds 25 mm, preferably lying between 40 and 100 mm.
• the light receiver is a detector plate sensi ⁇ tive for light in a wide spectrum, preferably all of the wavelength range to be examined, prefeably having an effective area exceeding 500 mm 2 , especially lying between 500 and 10000 mm 2 .
• effective area refers to the area receiving light from the light source.
• Such a detector with a wide spectral range may be used for determining the transmittance or absorbance at a number of different wavelength intervals.
• the relatively large surface area increases the signal-to-noise ratio.
• the measuring volume becomes large, so that fluctuations or inhomogeneities in the material are evened out, and a representative sample quantity is pro ⁇ vided more quickly.
• the detector may consist of a number of smaller plates of e.g. 100-200 mm 2 being inter-connected to act as one large detector plate.
• the plate is preferably used without lenses or similar optical systems in front, that would otherwise attenuate the light and limit the field of vision of the plate.
• the detector plate with its fittings is placed directly on the tube, whereby a large field of vision and small losses of light are achieved.
• One embodiment according to the invention is characterized in that the light source and the light receiver are of the wide-spectrum type, and that in the beam path between the light source and the light receiver there is placed a rotatable filter disc with cut-outs placed about its shaft at uniform distances, in which cut-outs filters are inserted, each allowing a respective wavelength inter ⁇ val to pass, whereby one filter at a time can be placed in the beam path by means of a motor connected to the shaft of the filter disc.
• the light source consists of a number of narrow-band light sources, each emitting light in a respective wavelength interval, preferably 4- 20 monochromatic laser diodes placed on one side of the tube segment, each emitting a respective wavelength in ⁇ terval within the range between 700 and 1200 nm.
• the light source may comprise a light-conducting cable, so that the light-producing part can be placed in a sepa ⁇ rate cabinet separate from the measuring device. The heating effect is reduced and a certain focusing of the light is achieved.
• the detector may comprise a light-conducting cable, such that the detector may be placed in a separate cabinet.
• the apparatus according to the invention may comprise a control unit to cause the repetition of a measuring proce- dure comprising the introduction of new material in the tube segment and measurement of the effect of the material upon the light.
• Optimum measuring conditions may e.g. be achieved by using the apparatus to carry out the near-infra-red meas ⁇ urements with a physical path length in the measuring tube of e.g. 40 to 60 mm, by having the sample remain stationary during the fraction of a second in which the measuring is carried out, and by having the sample being as free from air pockets as possible during the measuring process; this may be achieved by means of compression.
• the present invention also relates to a device for con- veying samples in connection with the examination of flowable material.
• This device comprises a tube having an opening for receiving a material, an opening for dis ⁇ charging material and a tube segment adapted for making measurements; a movable closure means placed in the tube at the opening for receiving material, and a conveying means to move material having been received into the tube segment adapted for making measurements.
• the closure means may be adapted to be opened in connec ⁇ tion with the reception of material and to be closed in connection with the conveying of material having been received toward said tube segment. This will prevent the sample from changing during the measuring process, e.g. by flowing back.
• the device may comprise a second closure means in the tube on the same side of said tube segment as the dis ⁇ charge opening, said second closure means being adapted to be closed during a period while the conveying means introduces new material into the tube segment, and to open when material having been examined is to be moved out of the tube segment.
• the conveying means is preferably a plunger adapted to slide in a fluid-tight manner along the inside of the tube.
• the device preferably comprises one or a number of pneu ⁇ matic cylinders with pistons to act upon the conveying means and/or the closing means in the tube.
• the device may be adapted to compress the material in the tube segment before the examination is carried out, preferably to a pressure of between 200 and 2000 kPa (2 and 20 bar) .
• a pressure of between 200 and 2000 kPa (2 and 20 bar) preferably to a pressure of between 200 and 2000 kPa (2 and 20 bar) .
• particles or “grains” are referred to, their sizes are preferably 1 mm or more, especially 3 mm or more, the material especially being present in its natural form, e.g. as a natural product, or as a material only having been subjected to coarse comminution, i.e. not in a finely comminuted or homo ⁇ genized form.
• Figure 1 shows an embodiment of an apparatus according to the invention for examining a flowable material
• Figure 2 shows a variation of the embodiment of Figure 1 comprising a light-conducting cable
• Figure 3 shows another embodiment of the apparatus accord ⁇ ing to the invention comprising laser diodes
• Figure 4 is a graph showing the transmittance as a func ⁇ tion of wavelength of meat samples with high and low fat content, respectively, having been measured in the equip ⁇ ment shown in Figure 1,
• Figures 5a-5f show various operating positions of a device according to the invention for conveying a material being used in connection with the apparatus of Figure 1, and Figures 6 and 7 show how the apparatus and the device are mounted on a mixer.
• the measuring device in Figure 1 comprises a tube segment 10b serving as a measuring chamber in connection with the measurement of the transparency of a meat material to infra-red light at various wavelengths.
• a tube segment 10b serving as a measuring chamber in connection with the measurement of the transparency of a meat material to infra-red light at various wavelengths.
• it comprises two windows 24 made of glass or other transparent material inserted in cut-outs in the tube wall facing each other.
• a measuring device or housing 25 with various means for measuring the transparency of the material present between the windows 24 is placed on the tube section 10b.
• a broad-spectrum light source 32 emits light within the operating range, in the present case the near-infra-red interval between 700 and 1200 nm.
• the light source 32 comprises or constitutes a tungsten-halo ⁇ gen lamp emitting a major proportion of the input of electrical energy in the infra-red spectral range and having a power rating of between 20 and 70 W or more, e.g. 100 W.
• a rotatable filter disc 34 with 6-20, e.g. 12, different filters 35 is placed between the light source 32 and the windows 24 in the tube segment 10b, each of said filters 35 allowing passage of light of a respective wavelength interval through the windows 24 in the tube segment 10b.
• the narrow-band light entering through the left-hand window passes through the material in the tube suffering a substantial loss and exits through the right-hand window, after which it impinges upon a wide-spectral photo-detector 36, e.g. a plate assembled from a number of Si wafers.
• the attenuation of the light in the material is due to the absorption caused by the various components of the material as well as the dispersion and reflection of the light as a consequence of phase transitions or particles in the material.
• the absorption depends on the components and the wavelength.
• the photo-detector 36 will produce signals depending on the content of components in the material being meas- ured and the wavelength.
• the signal is amplified, fil ⁇ tered, digitized and stored in an electronic memory.
• the windows 24 and the beam path are dimensioned in such a manner, that the detector 36 receives light having passed through a volume of material of more than 100 ml.
• the volume of material corresponds to the volume of the space between the windows 24.
• the measuring device comprises a motor 37 for rotation of the filter disc 34, so that the filters 35 one by one can be placed in the beam path between the light source 32 and the detector 36.
• a motor 37 for rotation of the filter disc 34 so that the filters 35 one by one can be placed in the beam path between the light source 32 and the detector 36.
• the signal from the detector 36 is recorded and stored, said signal having a strength depending on the absorption in the wavelength interval of the filter of the material being measured.
• the light source 32 is placed in a separate enclosure.
• the light is conducted via a lens 38 through a fibre cable 39, from the far end of which it radiates against the filter 35.
• the photo- detector 36 is the same as in Figure 1, but a correspon ⁇ ding arrangement with a light-conductor cable may, if so desired, be placed on the detector side.
• Figure 3 shows such an embodiment, using laser diodes instead of the lamp and the filter disc.
• the arrangement of Figure 3 has the advantage of having no moving parts.
• the arrangement of Figure 3 comprises a number of (power) laser diodes 40, each emitting light of a respective wavelength towards the material sample. Typically, 4-20 diodes are used, placed on the same chip. Each laser diode emits light of a respective wavelength within the range from 800-1050 nm, so that the use of filters is not necessary.
• a PMT detector 41 is used for sensing the light having passed through a sample of thickness 5-10 cm. By activating one diode at a time it is possible by means of the detector 41 to measure how much light penetrates through the sample at the various wavelengths.
• Figure 4 shows the signal from the detector 36 of Figure 1 during one revolution of the filter disc 34. The fully drawn curve represents a finely minced sample of pork with a fat content of approximately 50%.
• the sample is placed in the tube segment 10b.
• the lightly drawn curve has been recorded with a finely minced sample of beef with approximately 5% fat.
• the samples attenuate the light approximately 4000 times.
• the peak values represent the transmittance at the 11 different wavelengths. It can be seen that the samples attenuate the light dif ⁇ ferently at the various wavelengths because of the dif ⁇ ferences in fat and water content in the samples, this being used for computing these values.
• a data processing unit Based on the stored measurement values, a data processing unit automatically computes the content of e.g. fat in the material, said unit having been provided with a pro ⁇ gram with the necessary computing routines.
• the material is uniform in nature, e.g. as in the case of finely minced meat or meat emulsions, satisfac ⁇ torily accurate results may be achieved by only carrying out a single measuring cycle.
• the stored measurement values it is possible to determine the content of various components in the material, e.g. fat, protein, collagen and water. If a number of sets of measuring values, each having been obtained by means of a respective measuring cycle, are used, a substantial improvement of the accuracy of the result will be achieved, which is of special importance when the quantity being measured in each cycle is not representative.
• the samples being measured in the apparatus of Figure 1 may be removed from and introduced in the measuring seg ⁇ ment 10b of the tube 10 by means of the device shown in Figures 5a-5f, illustrating different operating positions in an operating cycle.
• the device comprises a tube segment 10b, being the same as the tube segment 10b of Figure 1.
• the tube segment 10b is connected to two other tube segments 10a and 10c, that are angular so that the tube 10 formed by the three segments 10a, 10b and 10c consists of a vertical central part and two horizontal end parts.
• the device is mounted on a mixing tank 2. In the vertical wall of this tank to the left in Figure 6 and close to the bottom, an opening has been cut to fit the lowermost horizontal end part of the tube, and at a level above the shaft 3, a second opening is cut to fit the upper horizontal parts of the tube.
• the plant shown in Figure 6 and 7 comprises a usual mixer 1 with a mixing tank 2, adapted to accommodate between 500 and 6000 kg meat material according to need.
• a mixing tank 2 In the tank 2 , there are two mixing devices consisting of two mutually parallel shafts 3 with radial rods carrying blades 4. The mixing devices may be rotated in both direc ⁇ tions by means of a motor arrangement 5.
• the arrangement is controlled by means of a control panel 6 on which an operator inputs the mixing program suitable for the pro ⁇ duction in hand.
• the tank 2 On one side, the tank 2 carries a worm conveyor 9, pro ⁇ viding an additional possibility of discharging material from the tank.
• the worm conveyor 9 may be terminated by a perforated disc with a rotating set of knives adapted to comminute the material during the discharge.
• EP-A- 0,569,854 (WOLFKING DANMARK A/S) comprises a description of such a type of mixing machine.
• a control unit 6a situated below the control panel 6 serves to control the functions of the plant and to re ⁇ ceive and process data from the measuring device 25 on the tube 10, e.g. signals expressing the fat content of the sample.
• the unit 6a is connected to the control panel 6 of the mixer 2, so that the processed data from the apparatus can be displayed to the operator or used for automatic monitoring and control of the mixing program contained in the control panel.
• the device for taking samples from the container 2 comprises a cylin ⁇ der 14 mounted by means of a flange 13 and closed at the lower end.
• the cylinder 14 there are two pistons 15 and 16.
• the upper piston 15 comprises a short tube 17 capable of sliding in a lowermost vertical part of the tube segment 10a, while the lower piston 16 carries a plunger 18 having an outer diameter corresponding to the inner diameter of the short tube 17, so that the plunger slides within the short tube.
• the black areas in Figures 5a-5f represent gaskets providing seals between movable parts.
• air under pressure may be in ⁇ troduced into the interspace between the pistons 15 and 16, so that the piston 15 is made to move upwardly.
• Coup ⁇ ling parts 22 and 23 for the connection of compressed- -air tubes or hoses are also provided in the bottom of the cylinder 14 and in the flange 13 constituting the top of the cylinder.
• the central part of the tube segment 10b serves as a measuring chamber in connection with measurements of the transparency of the meat material to infra-red light of various wavelengths.
• the upper tube segment 10c comprises a flange 26 carrying a cylinder 27 closed at one end.
• a movable piston 28 on the right-hand side of which is mounted a plunger 29 adapted to slide within the hori ⁇ zontal part of the tube segment 10c.
• a coupling part 30 for a compressed- -air tube In the bottom of the cylinder 27 there is a coupling part 30 for a compressed- -air tube, and the flange 26 comprises a similar coupling part 31 for compressed air.
• Compressed air is admitted to the space between the pis ⁇ tons 15 and 16, causing the piston 15 with the short tube 17 to move upward to an upper abutment position shown in Figure 5b, in which the short tube 17 entraps the material having been forced into the vertical part of the tube by the mixing devices, the tube already having been closed at the top by the plunger 29.
• the entrapped material is compressed by compressed air being admitted into the space between the bottom of the cylinder 14 and the piston 16 via the coupling part 22, so that the piston 16 with the plunger 18 is moved upwardly while reducing the space available for the en ⁇ trapped material.
• the pressure is equalized by means of the duct 20 and a counter-pressure valve placed on the latter's compressed-air tube and adjusted to a certain pressure.
• the vertical part of the tube 10 mainly contains air, for which reason the piston 16 with the plunger 18 moves upwardly to an uppermost position, in which the piston 16 abuts against the lower side of the piston 15. After a few cycles have been carried out, the vertical part of the tube 10 will, however, mainly contain meat material and only a lesser proportion of air. This is the operating situation now to be described.
• the pressure in the vertical part of the tube 10 is equalized with atmosphere by moving the piston 28 with a plunger 29 towards the right, compressed air being admitted on the right-hand side of the piston via the coupling part 31.
• the material can expand from here out into the hori ⁇ zontal part of the tube in the tube segment 10c and from there out into the tank 2.
• the piston 16 with the plunger 18 is forced to the uppermost position shown in Figure 5e, causing additional material to be removed from the vertical part and to be forced out into the tank 2.
• the piston with the short tube 17 and the piston 16 with the plunger 18 will be moved towards their lowermost positions, pressure being applied to the upper side of the piston 15 via the compressed air conduit secured to the coupling part 23.
• the increase in volume will create a sub-atmospheric pressure.
• passage is created between the vertical part of the tube and the lower horizontal end part in the tube segment 10a, so that material will be sucked into the vertical part of the tube.
• the opening of the passage preferably occurs simultaneously with a blade 4 being opposite to the open ⁇ ing close to the bottom of the tank 2, so that at the same time, the material will be subjected to suction on one side and pressure on the other side. In this manner, new material is introduced into the tube segment 10a.
• the pistons 15 and 16 have reached their lowermost positions and the piston 28 is in its extreme right-hand position ( Figure 5a) , a portion of material in the ver- tical part of the tube will again have been expelled out into the tank 2 and a new portion of material will have been taken in from the bottom of the tank for successive compression and measuring in the vertical part of the tube 10, thus completing a working cycle.
• This working cycle may immediately be succeeded by new and similar working cycles in a given rhythm, e.g. one per second (making the cycle time one second) .
• the inside diameter of the vertical part of the tube 10 and the stroke volume of the plunger 18 may e.g. be dimensioned in such a man- ner, that each working cycle brings between 60 and 400 ml new material into the tube. After one or a few working cycles, the new material will have been introduced into the space between the windows 24, after which measurements may be carried out.
• the quantity of material necessary for a representative measurement de ⁇ pends on the type and particle size of the material.
• the measurement values from each sampling and measuring cycle may be used to check whether the material is processed in an optimum manner, e.g. whether a mixing process is sufficiently thorough.
• the fat content of the material may e.g. be computed each time a sample is taken and measured, and the result compared with the previous result or the average of a number of immediately preceding results. If a great deviation is found, this is a sign that the material in e.g. the mixing tank is still hetero- genenous, and that the mixing process should continue. If the deviation is only a minimum or lies below a pre ⁇ determined limit, it is not possible to improve the homo ⁇ geneity of the material by continuing the mixing process, for which reason it is terminated. In this manner, it is normally possible to shorten the mixing process to what is strictly necessary, and the material is saved from being subjected to continued mechanical processing.
• the standard deviation of the results may be used. If the computed standard deviation for the most recent cycles falls below a predetermined level, or if it is not improved by continuing the mixing process, this is a sign that the mixing process should be terminated.
• control unit 6a All these computations and evaluations may be carried out automatically by the control unit 6a on the basis of measuring data received.
• this unit by means of an included program e.g. finds the results to be stable, it can automatically signal to the control panel 6 that the mixing operation is finished as far as homogeneity is concerned, after which the control panel itself or an operator having observed a signal from it may stop the motor arrangement driving the mixing devices.
• the measurements are carried out using near-infra-red radia ⁇ tion. It is also possible, however, to examine the mate ⁇ rial being advanced in the tube 10 by means of other types or a number of different types of electromagnetic energy.
• a further tube segment may be inserted down- stream of the tube segment 10b and having measuring de ⁇ vices for determining the content of liquid water in the material by means of microwave energy.
• the content of ice in the material may be determined as the difference between the water percentage determined by means of near-infra-red measurement in the tube segment and the water percentage determined by means of microwave measurements.

Landscapes

• Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Biochemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Health & Medical Sciences (AREA)
• Analytical Chemistry (AREA)
• Spectroscopy & Molecular Physics (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Dispersion Chemistry (AREA)
• Investigating Or Analysing Materials By Optical Means (AREA)
• Sampling And Sample Adjustment (AREA)
• Optical Measuring Cells (AREA)

Priority Applications (5)

Applications Claiming Priority (4)

Related Child Applications (1)

Publications (1)

Family

ID=26063285

Family Applications (1)

Country Status (9)

Cited By (5)

Families Citing this family (9)

Citations (4)

Family Cites Families (6)

• 1996
  • 1996-01-26 DK DK009096A patent/DK171926B1/da not_active IP Right Cessation
  • 1996-02-09 ES ES96901729T patent/ES2197230T3/es not_active Expired - Lifetime
  • 1996-02-09 CA CA002212626A patent/CA2212626A1/en not_active Abandoned
  • 1996-02-09 DE DE69627987T patent/DE69627987T2/de not_active Expired - Fee Related
  • 1996-02-09 AU AU46194/96A patent/AU4619496A/en not_active Abandoned
  • 1996-02-09 WO PCT/DK1996/000066 patent/WO1996024835A1/en active IP Right Grant
  • 1996-02-09 EP EP96901729A patent/EP0808451B1/en not_active Expired - Lifetime
  • 1996-02-09 US US08/875,877 patent/US6020588A/en not_active Expired - Fee Related
  • 1996-02-09 AT AT96901729T patent/ATE239909T1/de not_active IP Right Cessation
• 1999
  • 1999-12-17 US US09/466,511 patent/US6236048B1/en not_active Expired - Fee Related

Patent Citations (4)

Also Published As

Similar Documents

Legal Events