SE521908C2

SE521908C2 - Separating stones from wood, e.g. wood chips or sawed timber, by analysing noise inside vibrating boxes to detect presence of stones

Info

Publication number: SE521908C2
Application number: SE9901495A
Authority: SE
Inventors: Sven Aake Svensson
Original assignee: Sven Aake Svensson
Priority date: 1999-04-27
Filing date: 1999-04-27
Publication date: 2003-12-16
Also published as: SE9901495D0; SE9901495L

Abstract

Small pieces of wood are transported in a forwards direction by tilting and vibrating boxes (6) inside the separation machine. Noise from inside the box, which varies according to the wood material hardness and density, is processed electronically, and any noise caused by a stone striking against the inside of the box is converted into an electric signal for carrying out stone separation. The separation machine includes a trough having an inlet end with a rotating roll and an outlet end with one or more reversible, clad rolls for the wood. The machine contains a number of enclosing, vibrating box constructions. The box constructions are provided with measuring devices (10) for recording any change in frequency and amplitude/noise level.

Description

- 521 908 1:-* ~= Lådoma har med fördel retangulärt tvärsnitt med ena hömet pekande uppåt samt något avsmalnade mot sin fria ände vilket medför att stenar hamnar mellan lådorna och blir påverkade av dubbla vibrerande ytor. Lådoma kan givetvis ha annan utformning exempelvis med runt tvärsnitt eller av massivt gods med liknande egenskaper som en stämgaffel. l lådoma sitter avkänningselenient som registrerar frekvens och amplitud/ljudstyrka varvid en elektronikenhet med bandpassﬁltrering registrerar avvikelsen så att avskiljning kan ske. Avskiljningen sker genom att samtliga lådor vrids nedåt så att en öppning bildas mellan lådomas spets och efterföljade rulle samtidigt som nämnda rulle ändrar rotationsriktning. Efter det att den avvikande klangen upphört återgår lådorna till ursprungsläget och rullen får framåtmatande rotationsriktning. - 521 908 1: - * ~ = The boxes advantageously have a rectangular cross-section with one corner pointing upwards and slightly tapered towards its free end, which means that stones end up between the boxes and are affected by double vibrating surfaces. The boxes can of course have a different design, for example with a round cross section or of solid goods with similar properties as a tuning fork. In the boxes is a sensing element that registers frequency and amplitude / volume, whereby an electronics unit with bandpass filtering registers the deviation so that separation can take place. The separation takes place by turning all the boxes downwards so that an opening is formed between the tip of the boxes and the subsequent roll at the same time as said roll changes direction of rotation. After the deviating sound has ceased, the drawers return to the original position and the roller has a forward feeding direction of rotation.

Ytterligare särdrag som kännetecknar uppfinningen är genom kombinationen av iådornas konisitet och rörelse àstadkoms en utsålliiirig av småstyckigt material såsom barkstycken, små steriar. kvistdelar mm. 521 908 ;íffï:¿¿ gig 4 Utförandeexempel: Uppﬁnningens övriga särdrag framgår i samband med nedanstående beskrivning i anslutning till bifogade ritningar, på vilka figur l visar tvärsnitt genom maskinen i viloläge. figur 2 visar maskinen sedd från ovan. ﬁgur 3 visar tvärsnitt genom maskinen i altemativt utförande med kedjetransportör. figur 4 visar tvärsnitt genom maskinen i alternativt utförande med liöj- rich sänkbar rulle.Further features which characterize the invention are achieved by the combination of the conicity and movement of the lids, a screen of small pieces of material such as pieces of bark, small steroids. twig parts etc. 521 908; íffï: ¿¿gig 4 Exemplary embodiment: The other features of the invention appear in connection with the following description in connection with the accompanying drawings, in which figure 1 shows the cross section through the machine in idle mode. figure 2 shows the machine seen from above. Figure 3 shows a cross section through the machine in an alternative version with a chain conveyor. Figure 4 shows a cross-section through the machine in an alternative design with a slightly lowerable roller.

Den på ritningarna v isade anordningen för att genom vibrationer åstadkomma slag mot passerande material och därigenom indikera uppkommen ljudförändrirtg i en lådkonstrttktion mellan mjuk och hårt material varvid hårt material såsom sten kan avskiljas innefattande en bärande konstruktion (l) med sidoväggar sammanbuiidtia med. trianguellzt stag (2). Mellan sidoväggarna och på :tt rävar* plan vid initiatniiigsáiiidati atrordriad rulle (få) i 'fröjd tired inkoinnrzirrde transportörens drivtrunmia (Zl) och på ett lägre plan vid utmatningsändefri anordnade dubbla garnityrförsedda rullar (4~5) där rulle (5) ansluter mot efterföljande huggstup (3 l) eller transportör (41) iigß.The device shown in the drawings for causing vibrations against passing material and thereby indicating the resulting sound change in a box construction between soft and hard material, whereby hard material such as stone can be separated comprising a supporting structure (1) with side walls connected to it. trianguellzt stag (2). Between the side walls and on: tt foxes * planes at initiatniiigsáiiidati atrordriad roll (few) in 'joy tired inkoinnrzirrde conveyor's drive trunmia (Zl) and on a lower level at discharge endless arranged double garnished rollers (4 ~ 5) where rollers follow (5 ~ 5) chopping block (3 l) or conveyor (41) iigß.

Rulle (4) är lörsedd med tandade ringar vilka är placerade i delning mitt rnellan lådorna (6) och har till uppgift att förhindra stenar att studsar över rullen.Roller (4) is equipped with toothed rings which are placed in division in the middle of the drawers (6) and have the task of preventing stones from bouncing over the roller.

Mellan rullarna (3 och 4) är ett slutande plan anordnad bestående av ett antal lådkonstruktioner (6) med var sin vibrator (9) anbringade på axel (8) med gummibussningar (7). Lådorna har retangulärt tvärsnitt med ena liöniet pekande uppåt samt något avsmalnacle mot sin fria ände vilket medför att stenar hamnar mellan lådorna och blir påverkade av dubbla vibrerande ytor. l lådorna (6) sitter avkänningselement (l0) som registrerar frekvens och amplitud/ljtidstyrka varvid en elektronikenhet med bandpassliltrering registrerar avvikelsen så att zivskiljning kan verkställas.Between the rollers (3 and 4) a closing plane is arranged consisting of a number of box constructions (6), each with a vibrator (9) mounted on a shaft (8) with rubber bushings (7). The drawers have a retangular cross-section with one line pointing upwards and a narrow taper towards its free end, which means that stones end up between the drawers and are affected by double vibrating surfaces. In the boxes (6) there are sensing elements (10) which register frequency and amplitude / brightness, whereby an electronic unit with bandpass filtering registers the deviation so that ziv discrimination can be effected.

Axeln är intäst i lagring (l l) och försedd ned hävarm (ll) som påverkas av ställdoii eller cylinder (13), vid indikation av sten. så att saintligzt lådkotistruktioiter ( 6) vrids nedåt med vinkeln ot, varvid avskilj ning :iv sten från 'vedíiödet sker.The shaft is tested in storage (l l) and provided with a lever (ll) which is actuated by an actuator or cylinder (13), when indicating a stone. so that saintligzt lådkotistruktioiter (6) is turned downwards with the angle ot, whereby separation: iv stone from 'vedíiödet takes place.

Beroende på lådktiitstruktionens (6) storlek och vibratorns (9) utfomining kan det av praktiska skäl \ ara lämpligare att lådornçt behåller konstant lutning och att rulle (4) sänks vid indikation av sten enligt ﬁg4.Depending on the size of the drawer structure (6) and the design of the vibrator (9), it may for practical reasons be more appropriate for the drawer to maintain a constant inclination and for the roller (4) to be lowered when indicating stone according to ﬁ g4.

Claims

521 908 5 -f Patent claim

A method of separating stone from wood such as pulpwood, sawn timber or similar elongate pieces of wood, wherein a separation machine is provided, which comprises a trough shaped like a rectangular one, having a feed end with a rotating roller, and a discharge end having one or two reversible and gamitized rollers for the wood, and in which are arranged a number of sloping and vibrating box constructions, provided with sensing elements, which have the task of registering changes in frequency and amplitude / volume, characterized in that small pieces of material, such as bark, stone and the like, are transported forward due to the inclination and vibrations of the box construction, the hardness and density of the material in combination with blows from the boxes giving varying sound in the boxes.

Method according to claim 1, characterized in that the sound of the boxes is processed electronically, whereby the sound corresponding to the blow from the stone is converted into an electrical signal for separation.

3. A method according to claim 1, characterized in that when indicating a stone, the free end of the drawer structures is lowered so that the stone is separated from the wood solder.

Method according to claim 1, characterized in that when indicating a stone, the subsequent roll is lowered to the box constructions so that the stone is separated from the wood.

Method according to claim 1, characterized in that the drawer constructions can constitute solid metal rods type tuning rods.

Method according to claim 1, characterized in that the combination of the conicity and movement of the boxes is achieved by a sifting out of small pieces of material such as pieces of bark, small stones, twig parts etc.