SE509447C2

SE509447C2 - Equipment for analysing sound produced by particles

Info

Publication number: SE509447C2
Application number: SE9701758A
Authority: SE
Inventors: Stellan Ahlin
Original assignee: Stellan Ahlin
Priority date: 1997-05-13
Filing date: 1997-05-13
Publication date: 1999-01-25
Also published as: SE9701758L; SE9701758D0

Abstract

A grid or netting (7) causes the particles on rotation of the drum (1) not to slide along the bottom but forced upwards along the drum side, finally to drop through the holes of the grid or netting and then freely downwards towards the drum base, whereby the falling sound can be recorded by the microphones (2). The microphones pass the sound impulses or information concerning them to a chip or computer (5), which, or some other computer, can process the information covering the number of sound impulses, their positioning along the drum, strength, frequency, timing in relation to other falling sound, thus providing a particle analysis. The microphones can be placed in any suitable position on the drum.

Description

509 447 2 nya möjligheter, framförallt vad gäller snabbhet i anlysen, men också kan ytterligare annan information erhållas än enbart partiklarnas storlek. Dessutom kan exaktheten liksom säkerheten i analysen ökas, och material grövre än 5 cm kan lätt analyseras. 509 447 2 new possibilities, especially in terms of speed of analysis, but also other information can be obtained than just the size of the particles. In addition, the accuracy as well as the safety of the analysis can be increased, and materials thicker than 5 cm can be easily analyzed.

Provningen med uppfinningen kan ske med mobil utrustning, t.ex. vid produktionsplatsen, vilket ytterligare minskar den totala väntetiden för analysen. Genom teknikens utformning bör alla mer finkorniga prover undersökas i vatten, vilket helt eliminerar standardmetodens problem med fuktiga prover som mäste torkas, eller leriga prover som mäste tvättsiktas. Vattnet kan utan hinder tillsättas med fryspunktssänkande medel, sä att därmed analys kan ske utomhus också i kall väderlek. Grova prover kan analyseras valfritt vàtt eller torrt.The test with the invention can be done with mobile equipment, e.g. at the production site, which further reduces the total waiting time for the analysis. Through the design of the technology, all finer-grained samples should be examined in water, which completely eliminates the problems of the standard method with moist samples that must be dried, or muddy samples that must be screen-washed. The water can be added without hindrance with freezing point lowering agents, so that analysis can take place outdoors even in cold weather. Coarse samples can be analyzed optionally wet or dry.

Ett prov kan analyseras flera gånger för uppnàende av ökad kontroll, och flera prover ur ett visst material kan analyseras i snabb följd för att därmed öka analyssäkerheten. Stort dimensionerade utrustningar kan analysera mycket stora prover; alltsammans resulterar i högre analysnoggrannheten än med SS 13 21 12. Ett och samma prov kan analyseras med olika utformade galler/nät, och därmed erhålles ökad information om materialets egenskaper, t.ex. medelelongation.A sample can be analyzed several times to achieve increased control, and several samples from a certain material can be analyzed in quick succession, thereby increasing the analytical reliability. Large dimensioned equipment can analyze very large samples; all results in higher analysis accuracy than with SS 13 21 12. One and the same sample can be analyzed with different designed grids / nets, and thus increased information about the material's properties, e.g. mean elongation.

Gallret/nätet kan utformas med runda eller liksidigt fyrkantiga maskor, eller med avlånga hál, eller i form av parallella stavar vilka är oliklànga och därmed ger ökad spaltbredd längre bort fràn trummans vägg.The grid / net can be designed with round or equilateral square meshes, or with elongated necks, or in the form of parallel rods which are different lengths and thus give increased gap width further away from the wall of the drum.

Uppfinningen kan mäta antal, storlek och elongation hos partiklar större än 0.5 mm, samt ge information om ljud- hastigheten i partiklar större än 10 mm, i ett material.The invention can measure the number, size and elongation of particles larger than 0.5 mm, as well as provide information about the speed of sound in particles larger than 10 mm, in a material.

Undersökning kan alltsa utföras pà t.ex. jordarter, material för vägbyggnad, material för tillverkning av betong, men även andra material i vilka någon av ovanstående partikelegenskaper kan behöva undersökas, sà som spannmål och trindsäd, eller tekniska produkter så som blyhagel.Examination can thus be performed on e.g. soils, materials for road construction, materials for the manufacture of concrete, but also other materials in which any of the above particle properties may need to be investigated, such as cereals and pulses, or technical products such as lead shot.

Figur 1 visar utrustningen. För ett naturgrusmaterial med exempelvis partikelstorlek upp till 20 mm, kan den cylindriska trumman(1) ha måtten: längd en meter och diameter 3 dm.Figure 1 shows the equipment. For a natural gravel material with, for example, particle size up to 20 mm, the cylindrical drum (1) can have the dimensions: length one meter and diameter 3 dm.

Pà flera ställen fästs mikrofoner(2) med ledningar(3,4) till ett chips eller en liten dator(5), som fästs pà trumman. Trumman är antingen öppen i kortändarna eller öppningsbar/förslutningsbar genom en lucka(6). Invändigt sitter ett galler/nät(7) ut från trummans vägg. Gallret/nätet kan vara proportionsvis kort eller sà långt att det fäster mot motstàende vägg. Gallret/nätet kan ha runda, fyrkantiga eller avlånga häl. För analys av fördelningen av kornens storlek har gallret/nätet smà häl nära fästet mot trummans vägg och större hål längre ut fràn fästet.In several places, microphones (2) with wires (3,4) are attached to a chip or a small computer (5), which is attached to the drum. The drum is either open at the short ends or can be opened / closed through a door (6). Inside, a grille / net (7) protrudes from the wall of the drum. The grid / net can be proportionally short or so long that it attaches to the opposite wall. The grid / net can have round, square or oblong heels. To analyze the distribution of the size of the grains, the grid / net has small heels near the bracket against the wall of the drum and larger holes further out from the bracket.

Det kan finnas en serie olika grova galler till en viss mätutrustning, sa att gallret/nätet kan anpassas till materialet.There can be a series of different coarse grids for a certain measuring equipment, so that the grid / net can be adapted to the material.

Trumman hängs upp längs mittaxeln, med möjlighet att vrida den runt, antingen manuellt eller motordrivet. Längs något parti kan trumman vara försedd med ojämnheter invändigt. Det finns möjlighet att konstruera trumman av ljudledande material som delas upp av tvärgàende skikt med ljudisolerande material, för att därmed varje enskild ljudimpuls lättare skall kunna identifieras. 3 509 447 För grova material kan trumman göras stor; de finns ingen egentlig begränsning i detta avseende. Avén utrustningar i betydligt mindre skala än standardfallet är tekniskt möjliga.The drum is suspended along the center axis, with the possibility of turning it around, either manually or motor-driven. Along any part, the drum can be provided with irregularities inside. It is possible to construct the drum of sound-conducting material which is divided by transverse layers with sound-insulating material, so that each individual sound impulse can be more easily identified. 3 509 447 For coarse materials the drum can be made large; there is no real limitation in this regard. Avén equipment on a much smaller scale than the standard case is technically possible.

Provet läggs ner i trumman och denna fylls eventuellt med vatten, varpå den försluts. För t.ex. undersökning av en jordart, vrids trumman först nägra varv för att provet skall fördela sig, finmaterialet skall slammas upp i vattnet och klumpar lösas upp.The sample is placed in the drum and this is possibly filled with water, after which it is sealed. For e.g. examination of a soil type, the drum is first rotated a few turns so that the sample is distributed, the fine material is slurried in the water and lumps dissolve.

Därefter vrids det ytterligare några varv under vilka mätningen sker. När trumman vrids runt, kommer provet att kasa längs bottnen tills gallret tar emot. Detta lyfter upp provet tills det lyfts så högt att det börjar sila ner genom gallret/nätets hál, först med finkornigt material, så successivt grövre. Nedslaget av t.ex. en sandpartikel karaktäriseras alltså av att det sker tidigt, och nära gallret/nätet, samt också utgör en lätt ljudimpuls i motsats till en grövre partikel. Partiklarna kan alltså räknas genom att antalet ljudimpulser räknas, och dessutom kan ljudimpulsens tidsläge i sekvensen av ljud, liksom ljudimpulsens amplitud och frekvens registreras exakt. De flesta mikrofonerna är monterade på utsidan av det parti av trumman där invändigt nedslagen sker.Then a few more turns are turned during which the measurement takes place. When the drum is rotated, the sample will slide along the bottom until the grille receives. This lifts the sample until it lifts so high that it begins to sift down through the grid / net slippery, first with fine-grained material, then gradually coarser. The impact of e.g. a sand particle is thus characterized by the fact that it takes place early, and close to the grid / net, and also constitutes a slight sound impulse in contrast to a coarser particle. The particles can thus be counted by counting the number of sound pulses, and in addition the time position of the sound pulse in the sequence of sounds, as well as the amplitude and frequency of the sound pulse can be registered exactly. Most microphones are mounted on the outside of the part of the drum where the internal impact occurs.

När de tyngsta stenpartiklarna slår ner erhålles ljud som mäts också med mikrofoner på motsatt sida av trumman. Dessa ljud dämpas med en ökande slamhalt i vattnet, sä därmed kan vattnets halt av uppslammat finmaterial uppskattas, genom att det ljud som följer metalltrumman jämförs med ljudet som går genom det slammiga vattnet.When the heaviest rock particles strike, sound is obtained which is also measured with microphones on the opposite side of the drum. These sounds are attenuated with an increasing sludge content in the water, so that the water content of slurried fines can be estimated by comparing the sound that follows the metal drum with the sound that passes through the sludge water.

Genom byte till olika galler med olika utformning vad gäller placering, storlek och form hos hålen, erhålles för respektive material karaktäristiska sekvenser av nedslagljud, genom t.ex. att ett material med hög genomsnittlig elongation fàr ett annat mönster av nedslagsljud än ett kubiskt, i fall galler används med avlånga häl.By switching to different grids with different design in terms of location, size and shape of the holes, characteristic sequences of impact sound are obtained for each material, by e.g. that a material with a high average elongation has a different pattern of impact sound than a cubic one, in which case grilles are used with elongated heels.

Då materialet hasar runt på bottnen av trumman uppkommer för varje materialtyp karaktäristiska ljud när partiklarna gnuggar mot varandra, griper och frigör sig. Det för ett visst material karaktäristiska mönster kan förstärkas genom ojämnheter pà trummans insida.As the material hovers around the bottom of the drum, characteristic sounds emerge for each type of material as the particles rub against each other, grip and release. The pattern characteristic of a certain material can be reinforced by irregularities on the inside of the drum.

Partiklar större än 10 mm har nedslagsljud för vilka analys kan göras av ljudhastigheten i partikeln, vilket kan ge information om kvalitetsegenskaper hos materialet.Particles larger than 10 mm have impact sound for which analysis can be made of the speed of sound in the particle, which can provide information about the quality properties of the material.

Sekvensen av nedslagsljud, liksom hela mönstret av ljud som erhålles fràn ett visst material, utgör alltså en mycket innehållsrik information som lämpar sig för datorbearbetning.The sequence of impact sounds, as well as the whole pattern of sounds obtained from a certain material, thus constitutes a very rich content of information which is suitable for computer processing.

Claims

509 447 9 PATENT CLAIMS

1. l. Equipment for examining particles consisting of a drum (1), in which a material for testing can be placed and with microphones (2) and a chip or computer (5) for recording the sound particles in the drum when the drum produces rotated, characterized in that a grid or net (7) means that the particles when rotating the drum do not fall along the bottom but are forced up along the side of the drum and finally fall through the grid / measuring hole and then freely down towards the bottom of the drum whereby the impact sounds can be registered of microphones, which transmit the sound pulses or information about them to a chip or a computer, and this or any other computer can process the information about the number of these sound pulses, their location along the drum, strength, frequency, time in relation to other impact sounds, so that a particle analysis is obtained.

Equipment according to claim 1, characterized in that the grid or net is replaceable and that there may be several differently coarse and otherwise differently designed grids / nets for the drum, which may have equal or different sizes between themselves or on one and the same grid / net. holes, which may be round, square or oblong, or have a different shape, and in case the holes are of different sizes, that they are arranged with smaller holes closer and larger heels further from the grid / net bracket to the drum wall.

Equipment according to any one of the preceding claims, characterized in that the microphones can be placed on the drum in any way.

4. Equipment according to any one of the preceding claims, characterized in that a drum has irregularities inside, which have an effect on such particulate material lying inside the drum, so that when it is rotated the material is forced to rush over the irregularities in such a way that sound is generated, which can be measured with microphones placed on the outside of the drum.

Equipment according to any one of the preceding claims, characterized in - V, that the drum can be constructed in a uniform material or of two components, one of which covers the surface predominantly and has a high conductivity for sound, and the other insulates against sound .