EP1010508A1 - Roller screen or spreading machine - Google Patents

Abstract

The milling filter machine comprises a set of rolls (1) with mills (3) in the same direction of rotation (2). Each roller has its own defined upper side with an action end (B) and a number of ringed grooves separated by piston lands forming an outer cladding surface. The teeth of the ring grooves lie opposite the teeth of the ring land and are replaced by less than half of the pitch.

Description

The invention relates to a roller screen or scattering machine for Classifying or scattering wood chips, fibers or the like, with at least one set of rollers consisting of several Aligned parallel to each other, same direction of rotation having rollers, which together form a roller bed form, which extends across its length transverse to the rollers and a feed end for the screened or spreading material and a discharge end for coarse material, with each roller with its Top side defining the roller bed level towards the discharge end rotates and a plurality at the same axial distance from each other spaced ring grooves, which are separated from each other Ring webs are separated, the outer surface of the roller form, and with adjacent rollers so assigned to each other are that the ring webs of one roller the ring grooves of the neighboring Roller opposite and with these - in plan view seen on the roller bed level - largely on its circumference closed chip throughflow openings, perpendicular to the roller bed level form.

The invention further relates to the use of such Roller screen or spreading machine.

The problems encountered when screening or classifying as well Part of the relevant prior art are in the EP 0 328 067 B1. In this prepublished patent rollers are protected, the outer surface is provided with tapered projections through tapered valleys are separated. The neighboring ones Rollers are assigned to each other so that each the outer ends of the protrusions face each other are spaced by an axially parallel gap, which is the thickness of the chips to be screened.

The machine described in the introduction can be found in the US patent Take 2,966,267. Here are the ones with a smooth one Bottom formed ring grooves and a smooth surface ring webs each inclined to the roller axis.

The invention has for its object the screening or classifying effect to improve the machine described above.

This object is achieved in that the ring grooves and thus also the ring webs separating them in planes perpendicular to the roller axis, and that the outer lateral surface of each ring web by itself in the circumferential direction adjacent teeth is formed, the in Direction of rotation adjusted leading tooth flank steeper is as the adjoining one, to the foot of the following tooth flank sloping tooth back, being in axial Viewed in the direction of the ring web teeth of a roller an incline form, which is opposite to that of the adjacent roller has the same slope height.

The leading tooth flank of the rotating teeth exercises the particles of the screened or scattered material have a throwing effect, so that blockages of the roller set avoided and an accelerated Transport of the coarse goods in particular to the discharge end be guaranteed. Only the leading ones give active impulses Tooth flanks, while those falling on the back of the teeth Particles simply slide off from there. By the opposite each other ring web teeth rotating through a chip diaphragm opening will also clog these chip diarrhea openings prevented. The separation effect can essentially can be adjusted by changing the roller speed. For this, several can be connected in series, each with roller sets equipped with variable drives can be provided.

The separation effect can also be influenced by choosing different ones radial tooth heights possible. So can the last Rollers have ring web teeth with maximum tooth height.

Basically, it is possible to smooth the bottom of each ring groove to train. It has been developed for certain areas of application however proven to be advantageous, albeit the bottom of each ring groove by teeth adjoining one another in the circumferential direction is formed, the contour of which corresponds to the ring web teeth, the teeth of the ring groove in relation to the ring web teeth Circumferential direction offset by a fraction of a tooth pitch are and in the radial direction the tooth back of the axially adjacent Slightly protrude from the ring bar teeth.

To prevent particles of the sieve or grit in the To prevent grooves, it is useful if in the direction of rotation the teeth of the ring grooves opposite the teeth of the ring land are offset by less than half a tooth pitch.

The throwing effect described above is particularly effective, if the leading tooth flank with the through the Tooth root radius includes an angle of about 45 °.

It is also advantageous if between two adjacent rollers in plan view a straight gap with a thickness of about 0.2 x tooth height is formed. This relationship results deriving from the finding that the gap dimension from the load depends on the teeth, the load being higher for large teeth than with fine toothing.

A particularly inexpensive manufacturing process for the rollers can be achieved if each roller consists of individual prefabricated, rings on a roll body, wherein the roller body made of solid rod or thick-walled Pipe material can exist. The rings can be the same width from e.g. 3 mm, the rings forming the ring grooves have an outer diameter that is opposite the outer diameter the rings forming the ring webs around e.g. only about 2 mm is smaller. To form larger chip diarrhea openings then two or more identical rings axially next to each other to be ordered.

Is underneath the roller set against its conveying direction provided continuously rotating forming belt, it is for Improvement of the spreading pattern is advantageous if to achieve an additional pneumatic resolution of the chip flow Space between the roller set and the forming belt onto the air Extracting space against the conveying direction of the roller set Air suction device is connected.

Further features of the invention and their possible uses are the subject of the subclaims and are connected with further advantages of the invention using exemplary embodiments explained in more detail.

Figur 1

in Draufsicht eine Walzensieb- oder -streumaschine;

Figur 2

das in Figur 1 markierte Detail in vergrößertem Maßstab und schematischer Darstellung;

Figur 3

im Ausschnitt einen Horizontalschnitt durch einen Walzensatz einer Walzensieb- oder - streumaschine, bei der jede Walze aus einzeln vorgefertigten, auf einen Walzenkörper aufgezogenen Ringen besteht;

Figur 4

einen Horizontaischnitt durch eine linke Lagerung einer Walze gemäß Figur 3;

Figur 5

in Stirnansicht in ausgezogenen Linien einen Ring größeren Durchmessers, dem ein in gestrichelter Linie dargestellter Ring kleineren Durchmessers zugeordnet ist;

Figur 6

in vergrößertem Maßstab das in Figur 5 gekennzeichnete Detail;

Figur 7

in schematischer Darstellung einen lotrechten Schnitt durch eine Deckschicht-Streumaschine mit einem über einer Windkammer angeordneten Walzensieb;

Figur 8

in einer Darstellung gemäß Figur 7 die in Figur 7 dargestellte Deckschicht-Streumaschine mit über der Windkammer angeordneten Dosierwalzen;

Figur 9

eine Deckschicht-Streumaschine mit einer Einrichtung für eine zusätzliche pneumatische Auflösung des Spänestromes;

Figur 10

in einer Darstellung gemäß Figur 7 eine Mittelschicht-Streumaschine mit einem über einem Bunker angeordneten Walzensieb;

Figur 11

eine Ausführungsform gemäß Figur 10 mit geänderter Walzensiebanordnung und

Figur 12

einen Deckschicht-Walzenstreukopf gemäß Figur 9 sowie im oberen Teil der Figur ein mit dieser Walzenstreumaschine erzielbares Streubild.

Some exemplary embodiments of the invention are shown in the drawing. Show it:

Figure 1

in plan view a roller screen or scattering machine;

Figure 2

the detail marked in Figure 1 on an enlarged scale and schematic representation;

Figure 3

in the cutout a horizontal section through a roller set of a roller screen or scattering machine, in which each roller consists of individually prefabricated rings mounted on a roller body;

Figure 4

a horizontal section through a left storage of a roller according to Figure 3;

Figure 5

in end view in solid lines a ring of larger diameter, to which a ring of smaller diameter shown in dashed lines is assigned;

Figure 6

on an enlarged scale the detail shown in Figure 5;

Figure 7

a schematic representation of a vertical section through a top layer spreading machine with a roller screen arranged above a wind chamber;

Figure 8

7 shows the top layer spreading machine shown in FIG. 7 with metering rollers arranged above the wind chamber;

Figure 9

a top layer spreading machine with a device for an additional pneumatic dissolution of the chip flow;

Figure 10

in a representation according to FIG. 7, a middle layer spreading machine with a roller screen arranged above a bunker;

Figure 11

an embodiment according to Figure 10 with modified roller screen arrangement and

Figure 12

a top layer roller spreading head according to FIG. 9 and in the upper part of the figure a spreading pattern that can be achieved with this roller spreading machine.

Figure 1 shows a roller screen or spreading machine for classifying or on scattering wood chips, fibers or the like. Shown is a roller set 1, which consists of several axially parallel Side by side, same direction of rotation 2 (see Figure 5) comprising rollers 3, which together form a roller bed that is transverse in length to the Rolls 3 extends and a task end A for the screen or Spreading material and a discharge B for coarse material. Every roller 3 rotates with its upper side defining the roller bed plane towards the discharge end B and has a plurality of in the same axial distance from each other spaced ring grooves 4 (see Figure 2), which are separated from each other by ring webs 5, the form the outer surface of the roller 3. The ring grooves 4 and so that the separating ring webs 5 are each in planes standing perpendicular to the roller axis 6, with neighboring ones Rollers 3 are assigned to each other so that the ring webs 5th one roller 3 opposite the ring grooves 4 of the adjacent roller and with them - in top view of the roller bed level seen - on their circumference largely closed, vertical to the roller bed level, however, open chip throughflow openings 7 form, as can be seen in Figure 2. The width b the ring webs 5 maximum as large as that of the ring grooves 4. In particular Figure 2 also shows that between two neighboring Rollers 3 formed a straight gap 8 in plan view is.

According to the embodiments shown in Figures 3 to 5 the roller 3 consists of individual prefabricated, on a roller body 9 wound rings 10, 11. The roller body 9 made of solid rod or thick-walled tube material consist. In particular, FIGS. 3 and 4 recognize that the rings 10 of larger diameter that in Figure 2 schematically shown ring webs 5, the rings 11 smaller In contrast, the diameter embedded between two ring webs Form ring grooves 4.

The outer lateral surface of each ring web 5 is just like that Bottom of each annular groove 4 by themselves in the circumferential direction adjoining teeth 12 are formed, the second in the direction of rotation each leading tooth flank 12a is steeper than the next one, up to the base 12b of the next one Tooth flank 12a falling tooth back 12c. The closes leading tooth flank 12a with the tooth flank 12b Radius r an angle α of about 45 °. Figure 6 also leaves recognize that each tooth back 12c of the ring web teeth 12 with the tangent to its flight circle has an angle γ of Includes 3 ° -6 °.

The teeth 12 of the ring grooves 4 are similar to those of the ring webs 5 trained, but this in the circumferential direction by one Fraction of a tooth pitch t, preferably less than one half tooth pitch t offset. Figure 5 shows that the Annular groove teeth 12 in the radial direction of the tooth back 12c slightly protrude axially adjacent ring web teeth 12.

Seen in the axial direction, the ring web teeth 12 form one Incline 13, which is shown schematically in Figure 3. Around an even distribution of chips over the width of the To achieve roll bed, it is useful if this slope 13 the opposite of the adjacent roller is the same Has slope height.

According to Figures 3 and 4, the rings 10, 11 are in the axial direction by right-hand and left-hand nuts 14a and 14b braced against each other. For positive slewing ring the rings 10, 11 with the roller body 9, the rings with a nose 15 (Figure 5) in a down the length of the roller body 9 engage extending groove. In a convenient, in Alternative drawing not shown in the drawing instead on the outer surface of the roller body 9 with a Incline a projection on which the rings 10, 11th be pushed on with a recess in their inner ring contour can.

The separating effect of the roller screen or - Spreading machine can be adjusted by changing the roller speed. They can also form larger chip diarrhea openings 7 two or more identical rings 10 or 11 can be arranged axially next to each other. The width b of a ring 10 or 11 e.g. 3 mm. With an outside diameter D of about 60 - 70 mm (top layer machines) each ring 10 or 11 e.g. Have 16-20 teeth 12 and at an outer diameter D of about 70 - 80 mm (middle layer machines) are per ring 14 - 24 teeth provided. With wide Spreading machines have outside diameters of up to 100 mm. The radial tooth height h depends on the application and is in Top layer machines about 1 - 3 mm and in middle layer machines about 2 - 8 mm. The ring groove teeth are opposite the ring web teeth in the direction of rotation 2 only by an angle β of offset about 4 °.

According to FIG. 4, each roller 3 can be supported at both ends in pillow block bearings 16 his. The roller surface is designed to be wear-resistant, preferably chrome-plated.

Figure 7 shows a top layer spreading machine 17 with a chip bunker 18 for receiving the screen or grit 19, with a Bunker belt 20, which shows the screenings 19 in the direction of Promotes arrow to a discharge point, with in the chip bunker 18 arranged leveling rollers 21 for the screenings 19 and one scraping the pre-conveyed screenings 19 at the discharge point Spiked roller 22. Below the drop area is a provided with sieves 23 wind chamber 24, in the for horizontal register air flow symbolized by arrows 25 are arranged, which are connected to an air blower 26 are.

Below the above-mentioned belt discharge point of the bunker belt 20 A roller set 1 according to the invention is arranged, which acts as a roller screen works, so chip diarrhea openings 7 of the same size has and serves for the separation of coarse material 27, which over the Roll set 1 migrates from the feed end A to the discharge end B. and is dropped into a screw 28.

FIG. 8 differs from the top layer spreading machine 17 7 only in that the roller set 1 here as Dosing device works, that is to classify the spreading material 19 serves. The size of the chip diarrhea openings shown in Figure 2 7 therefore increases from A to B. Any coarse material will also thrown into the screw 28 here.

FIG. 9 shows a top layer spreading machine, at the chip flow is mechanically and pneumatically resolved. The chip bunker 18 corresponds with its internals 20, 21, 22 in essential of the embodiment according to FIG. 7. The sieve or Scatter 19 is thus from the bunker belt 20 in through the leveling rollers 21 equalized funding amount promoted and at the end the bunker belt 20 with the support of a rotating spiked roller 22, which can also be a rotating brush on one roller set 1 formed by spreading rollers. In one clear distance below the roller set 1 is that usual form tape 31, in the direction of the arrow and thus rotates counter to the conveying direction 33 of the roller set 1. A coarse-part screw 28 is arranged downstream of the roller set 1. To achieve an additional pneumatic resolution of the chip flow is the space between the roller set 1 and the Form tape 31 to the air of this room against the conveying direction 33 of the roller set 1 suction air extraction device 34 connected. For this there is between the start A of the roller set 1 and the air suction device shown on the right in FIG. 9 34 above the forming belt 31, a free suction channel 35 formed. The air suction device 34 generates below of the roller set 1 or 31 air speeds above the forming belt from 0.9 to 1.7 m / s. This gives you next to the mechanical resolution caused by the roller set 1 Chip streams also have a pneumatic resolution.

FIG. 10 shows a middle layer spreading machine 29. This is running the sieve or grit 19 to be introduced into the chip bunker 18 first via a roller set 1 working as a roller screen, the the coarse material already excretes and throws into the screw 28. The screened material is collected by a conveyor belt 30 and dropped in the chip bunker 18. That of his bunker band 20 thrown off screen or grit 19 is in one here device not of interest divided into two sub-streams and then arrives on a forming belt 31, as is also shown in Figures 7 to 9 is provided.

The embodiment according to FIG. 11 differs from that of Figure 10 only in that by the as a roller screen Working or set of rolls 1 passing through sieve or grit 19 falls directly into the chip bunker 18.

Figure 12 shows in its lower part in a schematic representation a plant corresponding to FIG. 9, in which the chip flow to be resolved mechanically and pneumatically. The Screening or scattering material, not shown in more detail, is more common Conveyed from a bunker belt 20 and at the end of the belt Support of a rotating brush 32 on one by spreader rollers formed roller set 1 thrown off. At a clear distance below the roller set 1 is the usual one Form ribbon 31, which is in the direction of the arrow and thus rotates counter to the conveying direction 33 of the roller set 1, to achieve the chip scattering pattern shown in the upper part of FIG however, was stopped. Between the beginning of A Roller set 1 and one shown at the bottom right in FIG. 12 Air suction device 34 is above the forming belt 31 a free suction channel 35 is formed, the length of which is at least of the roller set 1 corresponds. In addition to the 1 mechanical dissolution of the chip flow is obtained in addition, a pneumatic resolution to that in the upper Part of the chip scattering image shown in FIG. 12 leads. This Scattering pattern has occurred at a speed of rotation of the spreader rollers 3 of 325 rpm and at an air speed generated by the suction of 1.1 m / s. The spread was over a Period of 30 seconds with the ribbon 31 stopped.

The scatter diagram shows that the highest spreading height below the first spreading rollers of the roller set 1 shows that this maximum is considerably lower lies as without an air suction device, which causes a strong pull apart of the scatter pattern on the forming belt, the Extension of the spread pattern caused by the air extraction until far below the bunker belt 20.

Claims (27)

Roller screen or scattering machine for classifying or spreading wood chips, fibers or the like, with at least one roller set (1), which is composed of a plurality of rollers (3) which are arranged next to one another and have the same direction of rotation (2) and which together form a roller bed which extends in its length transversely to the rollers (3) and has a feed end (1) for the screened or scattered material (19) and a discharge end (B) for coarse material (27), each roller (3) with its top, which defines the roller bed plane, rotates towards the discharge end (B) and has a multiplicity of annular grooves (4) which are spaced apart at the same axial distance and are separated from one another by annular webs (5) which form the outer circumferential surface of the roller (3), and wherein adjacent rollers (3) are assigned to one another in such a way that the ring webs (5) of one roller (3) lie opposite the ring grooves (4) of the adjacent roller and with them - in a plan view of the roller bed plane e seen - form chip diaphragm openings (7) which are largely closed on their circumference but open perpendicular to the roller bed plane, characterized in that the ring grooves (4) and thus also the ring webs (5) separating them each in a perpendicular manner on the roller axis (6) standing levels, and that the outer circumferential surface of each ring web (5) is formed by teeth (12) adjoining one another in the circumferential direction, the leading tooth flank (12a) of which in the direction of rotation (2) is steeper than the adjoining one until Foot (12b) of the subsequent tooth flank (12a) sloping tooth back (12c), the ring web teeth (12) of a roller (3), seen in the axial direction, forming a slope (13) which is opposite to that of the adjacent roller (3) but has the same slope height. Roller sieve or scattering machine according to claim 1, characterized in that the leading tooth flank (12a) of the ring web teeth (12) encloses an angle (α) of approximately 45 ° with the radius (r) set by the tooth base (12b). (Figure 6) Roller screen or scattering machine according to claim 1 or 2, characterized in that each tooth back (12c) of the ring web teeth (12) encloses an angle (γ) of 3 ° -6 ° with the tangent to their flight circle. (Figure 6) Roller sieve or scattering machine according to claim 1, 2 or 3, characterized in that the bottom of each ring groove (4) is formed by teeth (12) which adjoin one another in the circumferential direction, the contour of which corresponds to that of the ring web teeth (12), the teeth (12) of the ring groove (4) being offset circumferentially from the ring web teeth (12) by a fraction of a tooth pitch (t) and the tooth back (12c) of the axially adjacent ring web teeth (12) in the radial direction tower over. (Figure 5) Roller screen or scattering machine according to claim 4, characterized in that the teeth (12) of the ring grooves (4) are offset by less than half a tooth pitch (t) in relation to the teeth (12) of the ring webs (5) in the direction of rotation (2) . (Figure 6) Roller screen or scattering machine according to one of the preceding claims, characterized in that the width (b) of the ring webs (5) is at most as large as the width of the ring grooves (4). Roller screen or scattering machine according to one of the preceding claims, characterized in that the width (b) of the ring webs (5) is approximately 3-9 mm. Roller screen or scattering machine according to one of the preceding claims, characterized in that a straight gap (8) with a thickness of approximately 0.2 x tooth height (h) is formed between two adjacent rollers (3) in plan view. (Figure 2) Roller screen or scattering machine according to one of the preceding claims, characterized in that the radial tooth height (h) is approximately 1-8 mm. Roller screen or scattering machine according to one of the preceding claims, characterized in that the ring webs (5) each have sixteen to twenty-four teeth (12) with an outer diameter (d) of approximately 60-80 mm. Roller sieve or scattering machine according to one of the preceding claims, characterized in that the ring webs (5) and grooves (4) of each roller (3) are incorporated in a one-piece roller body consisting of solid rod or thick-walled tube material. Roller screen or scattering machine according to one of Claims 1 to 10, characterized in that each roller (3) consists of individual rings (10, 11) which are clamped together in the axial direction and which are machined together. Roller screen or scattering machine according to one of claims 1 to 10, characterized in that each roller (3) consists of individual prefabricated rings (10, 11) mounted on a roller body (9). Roller screen or scattering machine according to Claim 13 , characterized in that the rings (10, 11) are braced against one another in the axial direction by nuts (14a, 14b) on the right and left-hand side on the end face. Roller sieve or scattering machine according to claim 13 or 14, characterized in that for the positive rotary connection of the rings (10, 11) with the roller body (9) on the outer surface of the roller body (9) with a slope is provided a projection on which Rings (10, 11) with a recess in their inner ring contour are pushed on. Roller screen or scattering machine according to claim 13, 14 or 15, characterized in that two or more identical rings (10, 11) are arranged axially next to one another in order to form larger chip throughflow openings (7). Roller screen or scattering machine according to one of the preceding claims, characterized in that each roller (3) is supported at both ends in pillow block bearings (16). Roller screen or scattering machine according to one of the preceding claims, characterized in that the roller surface is designed to be wear-resistant, preferably chrome-plated. Roller screen or scattering machine according to one of the preceding claims, characterized in that the separating effect can be adjusted by changing the roller speed. Roller screen or scattering machine according to one of the preceding claims, characterized by at least two roller sets (1), the rollers (3) of the second roller set seen in the conveying direction being wider than the rollers (3) of the first roller set and ring grooves (4) and webs ( 5) have. Roller screen or scattering machine according to claim 20, characterized in that the second roller set is arranged in a lower level than the first roller set. Roller sieve or scattering machine according to one of the preceding claims, with a forming belt (31) which is arranged underneath the roller set (1) and runs continuously against the conveying direction (33) of the roller set (1), characterized in that in order to achieve an additional pneumatic resolution of the Chip streams the space between the roller set (1) and the forming belt (31) is connected to an air suction device (34) which extracts the air of this space against the conveying direction (33) of the roller set (1). (Figure 12) Roller screen or scattering machine according to claim 22, characterized in that between the feed end (A) of the roller set (1) and the air suction device (34) above the forming belt (31) a free suction channel (35) is formed, the length of which is at least that of Corresponds to the roller set (1). (Figure 12) Roller sieve or scattering machine according to claim 22 or 23, characterized in that the air suction device (34) below the roller set (1) or above the forming belt (31) generates air velocities of 0.9-1.7 m / s. (Figure 12) Roller screen or scattering machine according to one of claims 1 to 21, characterized by its use as a roller screen in a top layer scattering machine (17) above a wind chamber (24). (Figure 7) Roller screen or scattering machine according to one of claims 1 to 21, characterized by its use as metering rollers in a top layer spreading machine (17) above a wind chamber (24) or a suction channel (35). (Figures 8 and 9) Roller screen or scattering machine according to one of claims 1 to 21, characterized by its use as a roller screen above the chip bunker (18) of a middle-layer scattering machine (29). (Figures 10 and 11)

Images