DE102007007276B4 - Armoring of the surfaces of roller press rolls - Google Patents

Abstract

Armoring of the surfaces of roller press rolls for pressure treatment, in particular fine bed crushing of granular material, characterized by the following features:
a) the material of the roll shell (10) consists of ADI (Austempered Ductile Iron), a nodular cast iron with bainitic structure;
b) in the surface of the roll shell (10) spaced-apart recesses for the autogenous wear protection are formed, wherein
c) the spaced-apart recesses formed in the roller shell (10) are longitudinally extending along roller covering lines through grooves (11) which are closed at their two ends located on the roller shell end faces by a respective fixed hard body (12 or 12 a), wherein the
d) radially and axially protrude and are fixed in the respectively located on the roll shell end faces recesses (13) hard body and prevent and push out the Gutmaterials on the Walzenmantelstirnseiten addition and form a roll armor on the roll edges with autogenous wear protection.

Description

The invention relates to an armor of the surfaces of roller press rollers for pressure treatment in particular Gutbettzerkleinerung granular Gutmateriales.

In roller mills granular brittle material in the nip, by which the two rotatably mounted counter-rotatable rollers are separated from each other, fed and subjected there to crushing. Also known is the so-called Gutbettzerkleinerung in the nip of a high-pressure roll mill, also called roller press, in which the individual particles of the drawn by friction in the nip Gutmateriales in a bed of good, d. H. be crushed each other in a compressed between the two roll surfaces bulk material when using a high pressure. The roller surfaces are exposed to a high compressive stress and wear stress.

In the DE 10 2004 043 562 A1 thick-walled annular bandages have been proposed for the press rolls of such roller presses as a roll shell whose material consists of a heat-treated spheroidal graphite cast iron with bainitic structure with retained austenite, such a material often being designated as "austempered ductile iron" (foundry practice No. 7/8). 1997, page 152). Such a material is characterized by the fact that the casting material hardens in the outer layers of the bandages as a result of external pressure loading of the bandage surface. It is also known to einzuformen in the outer surface of such ring bandages spaced recesses into which to be treated during operation of the roller press Gutmaterial which is to remain there during the roller revolutions form an autogenous wear protection for the drum surfaces and also have a good intake behavior due to its roughness should. However, the risk is not excluded that pressed in the roller press operation in the nip pressed material in an undesirable manner beyond the Walzenmantelstirnseiten out.

In DE 10 2009 050 636 A1 discloses a refining roll of ADI steel having parallel but wedge-shaped opening grooves on the grinding roll surface to the roll axis. Spaced grooves are complementary to each other with respect to the wedge-shaped course. A groove tapering on one end face is adjacent to two grooves which open on this end face and vice versa. The grooves are open towards the front edge.

In the DE 103 54 679 A1 Hard body of a grinding roller are disclosed sitting in a terminal edge on the end edge. However, the grinding roller is equipped with individual hard bodies, which are inserted in staggered rows of individual recesses.

Furthermore, it is known to armor the roll edges characterized in that in the region of the circumferential edge edges of the roll a circumferential groove is arranged, which is filled with hardfacing material.

Further, it is known from the brochure 2-201 d "Mahlanlagen KHD Humboldt Wedag", 7/2000, pages 18 and 19, the o. autogenous wear protection on the roller surfaces of roller presses thereby realize that on the roller surface a variety of prefabricated hard bodies such. B. powder-metallurgically produced knob bolt is disposed, which are embedded in corresponding holes of the roll shell, said anti-wear technology is called grid armor. In this case, the stud bolts protrude with such a large amount outward from the roller surface and they are spaced apart such that during operation of the roller press, the spaces between the stud bolts with the compressed fine-grained Gutmaterial filled in order to bring about the autogenous wear protection. This type of armoring of the surfaces of roller press rolls has proven itself in the case of comminuted bedding, in particular of ore material in practice. However, care must be taken to ensure that cracks in the roll shell, in particular at the base of the stud bolt bores, do not occur during operation due to the load on the stud bolts.

The invention has for its object to provide an armor for the surfaces of roller press rollers for the pressure treatment in particular Gutbettzerkleinerung granular Gutmateriales, which can overcome previous limits in terms of service life and height of usable roll pressure and wear resistance.

This object is achieved according to the invention with an armor having the features of claim 1. Advantageous embodiments of the invention are specified in the subclaims.

In the case of the press roll armoring according to the invention, the material of the roll shell consists of ADI (Austempered Ductile Iron). This material has a high elongation at break, compressive strength and toughness. Surprisingly, it has been shown that this highly alloyed material can be processed well with tools, so that incorporated recesses such. B. holes can be drilled for the use of z. B. pin-shaped hard bodies to enable the above-described autogenous wear protection. In addition, it has been shown that this material causes due to its Kugelgraphitgussgefüges possibly occurring microcracks to stop and has a high Rissunempfindlichkeit, so that the risk of cracking of the roll shell, starting from the bottom of the hole or groove bottom is minimized. On the contrary: The base material ADI forms during operation of the roller press under load by pressure hardening hard surface layers, which are able to retain the hard bodies used in recesses such as bores as stud bolts clearance and a roll shell wear by otherwise occurring micromovements of the hard body does not even occur ,

Because in the surface armor according to the invention, even when using hard bodies, the risk of cracking in the roll shell is minimized significantly higher compression pressures in the nip of the roller press for performing the energy-saving Gutbettzerkleinerung be applied, in which case, however, the tendency increases that a part of the autogenous wear protection material and the Good material pressed between the press rolls can be pressed undesirably beyond the roll shell end faces. To prevent this, at least on the roll shell end faces at the edges of hard bodies fixed radially and axially projecting from the roll shell and on the one hand form a dam for the pressed Gutmaterial and on the other hand wear protection for the Walzenmantelstirnseiten.

If, on the other hand, if peripheral weld beads running around the ring-shaped roll edges were welded on as welding layer edge bead rings in the case of a roll shell made of the material ADI, stress cracks would be produced which would be produced when welding on an unprofiled ADI material surface.

The roll pressure can be significantly increased according to the invention, without running the risk of cracks in the roll shell. Due to the possible increased pressing pressure with the use of hard bodies pressed into the interstices Good is still held securely for the autogenous wear protection even with relatively brittle the Gutbettzerkleinerung to be submitted Gutmaterials such. B. slag.

In the case of the press roll armoring according to the invention, the spaced-apart recesses formed in the roll shell are through-grooves extending along roll-walled lines, which are terminated at their two ends located on the roll shell end faces by a respective fixed hard body. For this purpose, however, can also be arranged on the roll edges ring segments which are releasably secured to the roll end face, in which case several such ring segments are each assembled into a circular ring, for. B. 8 pieces 45 ° ring segments or z. B. 12 pieces 30 ° ring segments.

In order to further minimize the danger of crack formation in the case of the press roll armoring according to the invention, the radially inner ends of the cylindrical or polyhedral hard bodies produced by powder metallurgy and the corresponding roll shell recesses or bores can have outwardly curved surfaces in their lowest area, approximately the curved shape of a hemispherical calotte. to prevent notch stresses in the roll shell.

The invention and its further features and advantages will be explained in more detail with reference to the embodiments schematically illustrated in the figures.

• 1: in perspektivischer Ansicht einen Ausschnitt aus einem an der rechten Stirnseite gelegenen Bereich einer dickwandigen Ringbandage als Walzenmantel einer Rollenpressen-Presswalze zur Gutbettzerkleinerung körnigen Gutmaterials mit einer ersten Ausführungsform einer Oberflächenpanzerung,
• 2: die Panzerung der 1, bevor die an den Walzenmantelstirnseiten fixierbaren Hartkörper eingesetzt worden sind,
• 3: die Panzerung der 1 und 2 mit Anwendung von zusätzlichen Schweißpanzerungen,
• 4: die Walzenpanzerung der 3 mit Rand-Hartkörpern einer etwas anderen Konfiguration,
• 5: ausschnittsweise die Stirnansicht eines gepanzerten Walzenmantels mit Rand-Hartkörpern wie bei 1 und mit über die gesamte Walzenoberfläche verteilten in Bohrungen angeordneten Noppenbolzen als Rasterpanzerung,
• 6-8: wiederum perspektivisch als weitere Ausführungsformen Presswalzenpanzerungen, deren Panzerung an den Walzenrändern durch profilierte und hartaufgeschweißte Ringsegmente zusammengesetzt sind.

It shows:

• 1 3 shows a perspective view of a section of a region of a thick-walled annular bandage located on the right-hand side as a roll shell of a roller press press roll for comminuted granular material with a first embodiment of a surface armor,
• 2 : the armor of the 1 before the hard bodies fixable on the roll shell end faces have been inserted,
• 3 : the armor of the 1 and 2 with application of additional welding armor,
• 4 : the roll armor of the 3 with edge hard bodies of a slightly different configuration,
• 5 : partial view of the front of an armored roll mantle with edge hard bodies as in 1 and with nubbolt bolts arranged in bores distributed over the entire roll surface as a grid armor,
• 6-8 : again in perspective as further embodiments press roller armor whose armor at the roll edges are composed by profiled and hard-welded ring segments.

In the roll armor of 1 As well as the other figures, the material of the cast as a thick-walled ring bandage roll shell 10 from ADI, a material that is easy to machine and high Rissunempfindlichkeit distinguishes. As well as in 2 clearly visible, are in the roll shell 10 spaced along roller mills lines, so axially extending through passage grooves 11 molded or incorporated, which at its two ends located on the roll shell end faces by a respective fixable powder metallurgically produced hard body 12 are completed, with the hard body at 2 left out but at the 1 and 3 already used. These hard bodies 12 are in radial recesses 13 of the roll shell 10 inserted in such a way that they project radially from the roll surface and also axially from the roll shell end face.

The distributed around the circumference of the Walzenmantelstirnseiten hard body 12 each have a cylindrical part 14 on, in the radial recesses 13 of the roll mantle 10 is fitted, causing the hard body 12 in the roll jacket 10 axially secured, while they are secured radially in particular by gluing. The attached to the cylindrical part 14 the edge hard body 12 outwardly adjoining part has a rectangular format in cross section.

In operation of the roller press are the groove-shaped recesses 11 filled with compressed fine-grained Gutmaterial that forms an autogenous wear protection. The at the roll shell end faces in the radial recesses 13 inserted protruding edge hard body 12 prevent pressing out of the autogenous wear protection material and pressed in the nip in the Gutbettzerkleinerung good material on the roll shell end faces out, and also serve these edge hard body 12 for wear protection of the two roll shell end faces.

Out 3 shows that the between the spaced grooves 11 lying Profilierungsvorsprünge the roll shell surface still consisting of hard aggregate hardfacing beads 15 can be armored. This additional welding armor creates no problems, since the welding stresses generated during buildup welding are almost completely reduced by the web-shaped profiling protrusions and the risk of cracking due to bottom cracks in the roll shell is avoided.

The edge-hard body 12a of the 4 differ from those of 1 to 3 in that on the cylindrical part 14 of the edge hard body 12a inward still a footbridge 16 is formed, with these webs 16 from the Nutenden ago in the Durchgangsnuten 11 extend and complicate a Walzstirnseitiges pressing out of Gutmaterial. In this embodiment, the risk of welding the edge hard body 12a through the surfacing worms 15 minimized.

The front view of the 5 leaves the over the circumference of the roll mantle 10 on the roll shell end side distributed edge hard body 12 respectively. 12a recognize as well as a variety of distributed over the entire roll surface in holes arranged stud bolts 17 as a grid armor for the autogenous wear protection, which grid armor can be arranged both on an unprofiled roll shell without the use of axial through grooves and on a profiled roll shell. To the risk of cracking in the roll shell 10 To further reduce, have the radially inner ends 18 the cylindrical stud bolt 17 and the corresponding holes in their deepest area approximately the curved shape of a hemispherical calotte. In operation of the roller press are the spaces between all protruding hard bodies 17 and 12 filled with compressed fine-grained material for autogenous wear protection.

According to embodiments of the 6 to 8th the press roll armor is formed at the roll edges not by circumferentially distributed single edge hard body, but by special ring segments, which are releasably secured to the roll end face, wherein a plurality of such ring segments are each assembled into a circular ring. In 7 is a single roll edge ring segment 19 drawn out, which extends over a circular arc of 45 °. 8 pieces of such ring segments 19 can be assembled into a circular ring. But it can also z. B. 12 pieces of such ring segments with a circular arc of 30 ° to be composed of a closed circular ring. In any case, it can be clearly seen that the ring segments 19 in cross section, an approximately U-shaped inwardly angled nose 20 with whom they like, like 6 can be seen in a lying in the vicinity of the roll shell end circumferential circumferential groove 21 of the roll mantle 10 are hung. Through the nose 20 with their connector are the ring segments 19 secured axially, while the radial securing is made by bolts passing through corresponding holes 22 . 23 etc. of the ring segments 19 through into the roll jacket 10 be introduced.

The material of the edge ring segments 19 can be made of steel or cast steel, which may still have a wear protection layer on its outer surface. The assembly / disassembly of the pressure roller edge armor produced in this way is very simplified according to the invention.

In any case, serve the ring segments to the operation of the roller press in the grooves 11 einzhresste Gutmaterial einbirnseitig and to prevent pushing out of the pressed Gutmaterials axially beyond the side edges of the press rollers out. The to the ring segments 19 molded axially extending short webs 24 . 25 etc. close the passage grooves 11 of the 6 Safe at both ends.

Also in the embodiment of 6 can as with 3 demonstrates that between the spaced grooves 11 lying Profilierungsvorsprünge the roll shell surface still consisting of hard aggregate hardfacing beads 15 armored, which then with respect to their outer circumference in a height with the outer periphery of the edge ring segments 19 lie.

One to the edge ring segment 19 of the 7 similar edge ring segment shows 8th , whose approximately U-shaped inwardly angled nose 20a has a slightly different configuration. Anyway, both on 7 as well 8th to recognize that the outsides of the angled noses 20 . 20a the ring segments spaced Nuteinbuchtungen 26 . 27 which have the grooves extending along generatrices in the roll shell surface 11 Limit at both longitudinal ends.

Claims (9)

Armoring of the surfaces of roller press rolls for pressure treatment, in particular fine bed crushing granular material, characterized by the following features: a) the material of the roll shell (10) consists of ADI (Austempered Ductile Iron), a nodular cast iron with bainitic structure; b) in the surface of the roll shell (10) spaced-apart recesses for the autogenous wear protection are formed, wherein c) in the roll shell (10) molded spaced apart recesses along roll generatrix extending through grooves (11) are at both of them on the roll shell end faces are each terminated by a fixed hard body (12 or 12a), the d) radially and axially projecting and fixed in the respectively located on the Walzenmantelstirnseiten recesses (13) hard body (12 and 12a) and a squeezing of the Prevent good material beyond the roll shell end faces and form a roll armor at the roll edges with autogenous wear protection. Armor after Claim 1 , characterized in that the hard bodies (12 or 12a) distributed around the circumference of the roll shell end faces each have a cylindrical part (14) which is fitted in the radial recesses (13) of the roll shell (10), the hard bodies (12 or 12) being fitted 12a) are caught axially in the roll shell (10) and radially secured by gluing. Armor after Claim 2 , characterized in that between the spaced grooves (11) lying profiling protrusions of the roll shell surface are still armored by hard materials existing build-up weld beads (15). Armor after Claim 1 , characterized in that the roll armor is formed at the roll edges by ring segments (19) which are releasably secured to the roll end side, wherein a plurality of ring segments are each assembled into a circular ring. Armor after Claim 4 , characterized in that the ring segments (19) seen in cross section have an approximately U-shaped inwardly angled nose (20, 20a), with which they hung in a lying in the vicinity of the roll shell end circumferential circumferential groove (21) of the roll shell (10) are. Armor after Claim 5 , characterized in that the outer sides of the angled lugs (20, 20a) of the ring segments have mutually spaced groove indentations (26, 27) delimiting the grooves (11) running along the roll surface lines in the roll shell surface at both longitudinal ends. Armor after Claim 1 , Characterized in that distributed in the radial recesses over the entire roller surface on the roller casing surface outwardly projecting hard bodies (17, 12, 12a) are inserted, said autogenous the spaces between all the foregoing hard bodies with an impacted fine durable material for the operation of the roller press Wear protection are filled. Armor after Claim 1 or 7 , characterized in that the hard bodies (12 or 12a, 17) manufactured by powder metallurgy and are cylindrical or polygonal. Armor after the Claims 7 and 8th , characterized in that the radially inner ends (18) of the hard body (17) and the roll shell recesses in their deepest region have outwardly curved surfaces, approximately the curved shape of a hemispherical calotte.

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