EP1239966B1 - Mill classifier - Google Patents

Abstract

A mill classifier, particularly a roller mill classifier, has a strip rotor and a concentrically arranged guide vane ring with flow-optimized guide vanes and flow channels for a parallel incoming and outgoing flow without constriction or with widening and a diffuser effect. The flow-optimized guide vanes with an incident flow tube with vertical rotation axis and at least one guide plate are arranged adjustably for a tangential to radial incident flow of the strip rotor.

Description

The invention relates to a mill classifier, in particular a roller mill classifier according to the preamble of the claim 1.

Wälzmühl classifier, which in a roller mill or in a roller mill, for example in an air-flow mill, can be arranged integrated or placed on this, can be designed as static or dynamic classifier be. Also known are combinations of static and a dynamic classifier, which then too be referred to as Hocheffectsichter.

A high-efficiency judge is in ZKG, 46th year (1993) issue 8, pages 444 to 450, Figure 7 described. The sifter points a cylindrical strip rotor and a concentrically arranged Leitklappenkranz on. Here is a possible effective tangential flow between the static Diaphragm and the inguinal rotor are generated so that the Coarse particles can not get to the rotor. disadvantage are an increased pressure loss and increasing wear the guide flaps, especially at high particle concentrations.

From EP 0 204 412 B1 a mill classifier is known, which has two superposed Leitklappenkränze. The baffles are adjustable around vertical axes arranged, wherein the guide flaps of the Leitklappenkränze independently have mutually supported axes. Between the Leitklappenkränzen a stationary ring is provided and the adjusting devices are at opposite ends the guide flaps arranged.

From FR 2 642 994 A1 there is a sifter with a strip rotor and a concentrically arranged Leitklappenkranz known. To improve the sighting are the vanes of the vane ring about a vertical axis adjustable. The strips of the rotor are designed in such a way that each channel with a widening from outside to inside Cross section are formed to achieve that the centrifugal forces and resistance forces acting on the Particles of a predetermined size act almost on the entire length of the channels are in equilibrium. The equilibrium conditions are thus determined by the profile of the rotor strips, the rotor speed and the employment of the Guides for different separation diameter achieved.

The cylindrical used in the aforementioned mill classifiers Last or Stabkorbrotor usually has a Number of bars, which is at least twice as high as The so-called standard classifiers is what with relatively high Cost of production is connected. Also the suspension and Storage of a bar coring machine differs from the Rotors of the standard classifier and contributes to the higher manufacturing and installation costs.

A well-known standard classifier is the Loesche gyro / Basket classifier type LKS (ZKG, 46th year (1993) Heft 8, p. 446, fig. 5). This dynamic sifter is called cone-shaped Ingot rotor formed and has a double cone rotor with screwed visible strips on. The slanted rotor bars correspond to the flow from below and lead to a weak deflection of the regrind fluid flow. In conjunction with a swirl flow, which by the employment of blades of a blade ring the mill is conditional, and one conically after The sifter rotor, which widens at the top, is created on the top rotor a radial flow, which increases from bottom to top and at the conically widening ledge rotor too different centrifugal forces and to a relatively uniform Sighting over the entire last length leads.

From DE 44 23 815 C2 a Hocheffektsichter is known in which a double cone rotor of a Loesche gyroscope / Basket sifter was preceded by a static sighting. By at least two axially superimposed and adjustable arranged Leitklappenkränze and a directed deflection the regrind fluid flow becomes part of the coarse material deposited before passing through the downstream conical Ingot rotor a dynamic Nachsichtung takes place. The classifier has an improved selectivity and a lower energy consumption compared to the standard classifiers but not always increasing demands on efficiency and as possible low manufacturing and maintenance costs.

The invention has for its object to provide a mill classifier, in particular a roller mill classifier, which has exceptionally low production costs in a particularly simple construction and at the same time allows great flexibility and optimization of the visual processes.

According to the invention the object is achieved by the features of the claim 1 solved. Advantageous and advantageous embodiments are in the description of the figures and in the subclaims contain.

A basic idea of the invention can be seen therein, the Advantages of a slat rotor of a Loesche rotary / basket sifter maintain and a purely dynamic sighting with the help of at least one Leitklappenkranzes reach, wherein the guide flaps and the rotor strips are formed in such a way and aligned with each other, that the Mahlgutpartikel not in orbit outside the inguinal rotor forced, but promoted into the inguinal rotor inside become.

According to the invention the guide flaps such a shape design and positioning on that no so-called Cyclone flow arises, but a regrind fluid mixture without an upstream static vision stage immediately is spotted dynamically.

According to the invention, a roller mill classifier with a strip rotor of basically known design and a concentric Leitklappenkranz arranged around the strip rotor provided with flow-optimized vanes, which um a vertical axis of rotation are adjustable and one of the Mill ascending regrind fluid flow to a tangential to radial flow of the rotor bars of the inguinal rotor to force.

In this case, rotor strips are preferably used, as they are from the LKS classifiers are known, but at least in the area the guide flaps vertically and thus parallel to the guide flaps are arranged.

It is in terms of manufacturing costs and efficient Sighting expediently, as ridge rotor a double cone rotor, in particular a Loesche gyroscope / basket sifter the type LKS to use and to convert this way, that the known rotor strips maintained, but to a cylindrical rotor area perpendicular and not more are arranged obliquely. By the rotor strips a have radial dimensioning as in an LKS classifier, can the number of rotor bars compared to the cylindrical rod-basket rotors of the high-efficiency classifier clearly be reduced. It was found that the number of bars at about one third of the fillet count of a rod-basket sifter and a maximum of 50%.

A selective sighting without an upstream static Sighting according to the invention by at least one Leitklappenkranz achieved with flow-optimized baffles, which has a rounded leading edge and at least have a baffle and which opposite the inguinal rotor be made such that an imaginary extension the baffles not on the inguinal rotor over, but at least tangentially to the outer edges of the rotor strips or until it leads radially into the rotor center.

Particularly advantageous are vanes with a rounded Leading edge and at least one arranged thereon Guide plate, such that approximately parallel or expanding Flow channels formed between two vanes be and the inflow and outflow is approximately equal.

In conjunction with the rounded leading edge arises a parallel flow without constriction in the outflow and by a particularly advantageous streamlined Formation of the baffles an expanding outflow with diffuser effect, with a recovery of pressure energy and thus a reduction of the flow resistance connected to the classifier. At level On the other hand, deflectors enter between two deflectors Flow channel formed with a nozzle effect.

A cost-effective production, installation and easy adjustment the flow-optimized vanes can be achieved when, as a rounded leading edge, a cylindrical or tubular Anströmkörper, e.g. a flow pipe, is used, on which the baffle tangential arranged, for example welded. It is also possible, the baffle indirectly, for example via a attach additional mounting plate to the flow pipe. While the mounting plate, which relatively can be kept narrow, fixed directly to the flow pipe can be, the baffle can be releasably attached to the mounting plate attached, for example, be screwed. In case of wear of the baffle is in this way a relatively quick, inexpensive replacement possible.

Conveniently, the flow pipe is circular cylindrical and made of an abrasion resistant material, and the axis of rotation the guide flaps is from the longitudinal axis of the flow pipe educated. This has the advantage that both the holder of the guide flaps, for example via Pivot, in the area of the classifier housing, and the adjustment from outside the classifier housing extremely low can be carried out.

Particularly advantageous for flow channels with diffuser effect are streamlined trained flaps. These can be formed for example by two baffles be, which on the Anströmkörper or Anströmrohr be attached tangentially. For production and storage It is advantageous if both baffles substantially identically formed and with rotor-side edge regions abutting one another, i. leak. The second sheet However, can be narrower than the baffle, which the Sichtgutstrom facing, be formed and with a other angle of attack than the Sichtgutstrom facing Baffle be attached to the Anströmkörper to a to cause opening flow channel with diffuser effect.

It has been shown that a selective sighting with a strip rotor and at least one Leitklappenkranz can be achieved, which has an equal number of rotor strips or have guide flaps. Basically you can the rotor strips Z-shaped.

An advantageous, flow-optimized form of the Z-shaped Rotor bars can be achieved when the to the baffles directed leg is rounded. This rounded Z-shape results in a lesser Resistance than the conventional angle shape. Furthermore The flexural rigidity of the rotor bars is increased, resulting in especially advantageous in a flying arrangement effect.

For a direct dynamic sighting over as much as possible the whole Reaching the rotor area are the heights of the baffles and the rotor bars matched. at a strip rotor, which a converted double cone rotor a Loesche gyro / basket classifier is the cylindrical rotor area above a conical rotor area to be dimensioned such that the vertical standing rotor strips of the cylindrical rotor portion approximately have the same height as the concentrically arranged Deflector flaps of the Leitklappenkranzes. The conical rotor area may advantageously be covered by a cover, e.g. a covering cone, which between the cylindrical and conical Rotor area is arranged, fluidically ineffective be made. As the inguinal rotor with its conical Rotor section already working within the foundry return cone, it is not necessary to use this area or the cover conical strip ends like a coat.

Conveniently, for the mill classifier according to the invention not just the rotor bars of the inguinal rotor like formed at LKS, but it can also be the classifier housing, at least the top of the classifier housing, the Bearing cartridge and also the drive and the drive shaft like be formed in a Loesche gyro / basket sifter. It is advantageous that the lower cone of the double cone rotor omitted and shortened the drive shaft can be. The classifier housing familiar from the LKS classifier can be taken in principle, but with the space for the rising regrind fluid flow over the height of the Leitklappenkranzes is narrowed, causing the Particle flow into the flow channels of the Leitklappenkranzes is accelerated into.

The mill classifier according to the invention makes it possible to use the entire Grist particles from fines to coarse material to the inguinal rotor to supply to a purely dynamic sighting. This Particle flow is after passing through the grinding gap between the grinding rollers and the grinding track in the fluid stream spun, flows as regrind fluid flow on the periphery the grinding bowl upwards and is through the Leitklappenkranz without prior separation of coarse particles in transported the inguinal rotor. The inguinal rotor singles by centrifugal separation, the coarse particles from the total particle flow by removing the coarse particles from the inguinal rotor be thrown against the Leitklappenenden where by gravity as oversize into the semolina recirculation cone fall.

It is within the scope of the invention, more than a Leitklappenkranz over the height of the cylindrical rotor portion of the Provide strip rotor and the vanes of each Leitklappenkranzes equipped with an adjusting device.

It is advantageous under the Leitklappenkranz a support ring to arrange.

Moreover, it is within the scope of the invention, instead of a Retrofitted rotor of a Loesche gyro / basket sifter to insert a rod cage sifter of a high-efficiency sight and with concentrically arranged, flow-optimized To provide baffles according to the present invention.

Essential advantages of the mill classifier according to the invention are relatively low manufacturing, assembly and storage costs as a result of the possible conversion of an LCS. Furthermore can by the possible conversion of a LKS quickly and without great effort according to customer wishes for one high-performance, cost-effective mill classifiers become.

Fig. 1

einen erfindungsgemäßen Mühlensichter mit einem Leitklappenkranz;

Fig. 2

eine zweite Variante eines erfindungsgemäßen Mühlensichters mit einem Leitklappenkranz;

Fig. 3

einen Ausschnitt eines Leistenrotors und vergrößert dargestellte Leitklappen eines Leitklappenkranzes;

Fig. 4

eine zweite Variante von Leitklappen und

Fig. 5

eine stark schematisierte Darstellung von Leitklappen und Rotorleisten eines Leistenrotors gemäß Figur 1 und 2.

The invention will be further explained below with reference to a drawing; in this show in a highly schematic representation

Fig. 1

a mill classifier according to the invention with a Leitklappenkranz;

Fig. 2

a second variant of a mill classifier according to the invention with a Leitklappenkranz;

Fig. 3

a section of a strip rotor and enlarged illustrated vanes of a Leitklappenkranzes;

Fig. 4

a second variant of baffles and

Fig. 5

a highly schematic representation of vanes and rotor bars of a strip rotor according to Figure 1 and 2.

An illustrated in Figure 1 and Figure 2 mill classifier is a Wälzmühl classifier 2, which on a Wälzmühle can be put on. The roller mill is by grinding rollers 37 and a grinding track 39 indicated.

The roller mill classifier 2 has a classifier housing 23 with a top 25 a dynamic separator part 6 and a static vane ring 4 for an upflowing Grist-fluid mixture 3 on. The feeding of the to be ground Aufgabeguts via a feed tube 30, which is arranged laterally on the classifier housing 23 and almost to to a discharge opening 33 of a semolina cone 31 ranges, so that the feed material together with that of the dynamic one Separator part 6 rejected semolina or coarse particles 32 a rotating grinding plate 39 and grinding rollers 37, respectively becomes.

As a dynamic separator part 6 is a known per se Strip rotor 16 with a cylindrical rotor portion 8 and a conical rotor portion 18 is used, which in relation on number and training, especially in terms of the radial width of the rotor strips 7, as well as in relation to a storage cartridge 24, one above, not shown drive and a drive shaft 26 substantially a double cone rotor of a Loesche gyroscope / Basket sifter corresponds. The conical rotor portion 18 is by a veneer, which by a cover cone 28th is formed in conjunction with the semolina cone 31, ineffective made. While in the upper cylindrical rotor area 8 in conjunction with the flow-optimized baffles 5 of the Leitklappenkranzes 4 a purely dynamic Sighting takes place, secure the sloping visual strips the conical rotor portion 18, the mechanical connection to the double cone rotor 35.

Also, the classifier housing 23 and the upper part 25 of the classifier housing 23 were in principle from the Loesche gyro / KorbSichter, a standard classifier, adopted, taking However, the classifier housing 23 in the region of the cylindrical Rotor region 8 tapers or narrows and upwards a "retracted" housing shape 38 results.

The mill classifier 2 shown in FIG. 2 corresponds in terms of of the classifier housing 23 except for the retracted Housing form 38 and in relation to the classifier housing upper part 25, the bearing cartridge 24, drive shaft 26 and in the form and radial extent of the rotor strips 7 also known The aforementioned LKS Standard Sichter, however, has in Contrary to the classifier of FIG. 1 no conical rotor area 18, but only a cylindrical rotor area 8 with vertical rotor strips 7 in the narrowing Housing 38 on. A double cone 35, as in the mill classifier 2 according to FIG. 1 is no longer present. Matching Features of the mill classifier 2 according to FIGS. 1 and 2 are provided with identical reference numerals.

The guide flap ring 4 of the mill classifier 2 in the figures 1 and 2 is provided with flow-optimized baffles 5, which can be adjusted about a vertical axis of rotation 9 (see Figs. 3 to 5). To get a dynamic view of the Ground stock-fluid mixture 3 and a separation into coarse material 32 and fines 34 by repelling the rotor bars 7 of the To reach bar rotor 16, the baffles 5 are so trained and arranged that in a viewing room 20 between the strip rotor 16 and the Leitklappenkranz. 4 no centrifugal flow, but a tangential flow until radial flow of the inguinal rotor 16 takes place (see Figs. 3 and 5).

Flow-optimized baffles 5 of the Leitklappenkranzes. 4 are shown by way of example in FIGS. 3 to 5. In a first training variant are in Fig. 3 in comparison to the rotor strips 7 shown enlarged guide flaps 5 with a rounded leading edge 10 and a baffle 11 provided, which directly and tangentially to the rounded Leading edge 10 is attached. Such baffles 5 are shown in FIG. 3 as lower deflectors, while the two upper baffles 5 streamlined are formed and next to the baffle 11, which the Ground material-fluid mixture 3 or facing the Sichtgutstrom is still have a sheet 12. The sheet 12, which the Is away tangent stream, is also tangential to the rounded leading edge 10, which advantageously a circular inflow pipe is attached.

To an opening flow channel 13 between two Can cause 5, the second sheet 12 with a different angle of attack than the baffle 11 at the leading edge 10 are attached. Baffle 11 and Sheet 12 of the two upper streamlined baffles. 5 of Fig. 3 are formed largely identical and are with rotor-side edge portions 21, 22 to each other and thus run "pointed". Streamlined baffles 5 but are not limited to this training variant.

Figure 4 shows alternatively trained vanes 5 with a Anströmrohr 10, a vertical axis of rotation 9 on the Longitudinal axis of the flow pipe 10, with a guide plate 11 and a sheet 12. In contrast to those shown in Figure 3 Leitklappen 5, the baffle 11 is not directly on the Flow tube 10, but via an additional mounting plate 17 and releasably attached to this. In this way can the exposed to wear baffle 11 replaced and be renewed. Conveniently, both the Guide plate 11 and the flow pipe 10 made of an abrasion resistant Material made or at least partially an abrasion resistant coating and / or surface structure on. Also, the plate 12 and / or the additional mounting plate 17 may be formed abrasion resistant. FIG. 4 clarifies that the angle of attack of indirectly fastened Guide plate 11 and / or the plate 12 the same or different can be chosen, which makes either parallel or expanding flow channels 13 formed and a sighting according to the respective requirements can be achieved.

FIG. 5 shows by way of example two rotor strips 7 of a strip rotor 16 shown. The rotor strips 7 are basically Z-shaped, but have at their the Leitklappenkranz 4 facing the end of a rounded Leg 27, which leads to a lower resistance and leads to a higher bending stiffness. The shown in Fig. 5 Guide vanes 5 have a rounded leading edge 10 also a flow pipe, whose vertical axis the axis of rotation 9 of the baffles 5 forms. The baffles 5 are provided with a baffle 11, which indirectly, namely on fastening devices, such as mounting plates 17, is held on the flow pipe 10. While the mounting plates shown in Fig. 4 17 angled are formed are for the baffles 5 according to Fig. 5 uses flat mounting plates 17, which attached tangentially to the flow pipe 10, for example welded, are.

The for a purely dynamic sighting of the mill classifier 2 intended employment of the Leitklappenkranzes 4 with respect to the rotor strips 7 is apparent from FIGS. 3 and 5. The Manifolds 5 with directly or indirectly on the flow pipe 10th attached baffles 11 or the streamlined formed Baffles 5, e.g. with a baffle 11 and a sheet 12, are aligned so that their imaginary Extensions, which are shown by solid lines are not past the inguinal rotor 16 but tangential to the outer edges of the rotor strips 7 to radially towards the center of the inguinal rotor 16.

In FIGS. 3 and 5 the guide flaps 5 are at an angle set at about 60 °, allowing a flow the radially oriented rotor strips 7 and a rejection Grobgutpartikel 32 takes place while the fines get into the inguinal rotor 16. In Figure 5 is at the bottom Guide flap 5 shown that the coarse particles 32 of the Z-shaped rotor strips 7 thrown towards the guide flap 5 and in this flow-minimized area fall down into the semolina cone 31 (see FIGS. 1 and 2). FIG. 3 and in particular FIG. 5 also illustrate the Training of approximately parallel flow channels 13 with an approximately equal flow 14 and outflow 15th due to the flow-optimized baffles 5 with baffles 11 and a Anströmkörper 10. In contrast, arise in the case of baffles without incident bodies, it is inevitable that they become narrowing Flow channels with a nozzle effect in the outflow, which is shown in Fig. 5 with dashed lines is. In the parallel flow channels 13 or in expanding flow channels, in which an advantageous Diffuser effect occurs and a recovery of printing energy is the entirety the particle of the regrind fluid stream from the roller mill, i.e. Fine material to coarse material, without prior separation from Coarse particles transported into the inguinal rotor 16. In the strip rotor 16 then the coarse material particles 32nd separated by centrifugal force separation from the rotor 16 by they are against the baffles 5, i. against armored baffles 11 or plates 12 (see Fig. 3 to 5) thrown become. By gravity fall the coarse material particles 32 in Viewing space 20 as oversize in the semolina cone 31 and become returned to the grinding path.

Claims (15)

1. Mill classifier, particularly roller mill classifier, with a dynamic classifier part (6) and a guide vane ring (4) for a rising grinding material-fluid flow, the guide vane ring (4) has guide vanes (5), which are adjustable about vertical rotation axes (9) and the dynamic classifier part (6) is a strip rotor (16) with rotor strips (7), which are concentrically surrounded by the guide vanes (5) of the guide vane ring (4), accompanied by the formation of a classifying area (20), whereby the strip rotor (16) is at least zonally cylindrically constructed and has a cylindrical rotor area (8) with vertical rotor strips,
   characterized in that
   the guide vanes (5) of the guide vane ring (4) have a flow-optimized shape with a rounded leading edge (10) and at least one guide plate (11),
   that the rotation axis (19) is formed in the area of the rounded leading edge (10),
   that the guide vanes (5) are adjustable to a direction tangential and a direction radial to the cylindrical rotor area (8) and
   that by in each case two guide vanes (5) is formed a parallel or widening flow channel (13) with diffuser effect.
2. Mill classifier according to claim 1,
   characterized in that
   the guide vanes (5) as a rounded leading edge have an incident flow body, particularly an incident flow tube (10) and the guide plate (11) is arranged directly and tangentially at the incident flow tube (10).
3. Mill classifier according to claim 1 or 2,
   characterized in that
   the guide plate (11) is fastened indirectly and by means of fastening elements, particularly fastening plates (17) to the incident flow tube (10).
4. Mill classifier according to claim 2 or 3,
   characterized in that
   the incident flow tube (10) of the guide vanes (5) has a circular cylindrical construction and the rotation axis (9) of the guide vanes (5) is formed by the longitudinal axis of the incident flow tube (10).
5. Mill classifier according to one of the claims 2 to 4,
   characterized in that
   the flow-optimized guide vanes (5) have a streamlined construction and e.g. besides the guide plate (11) a further plate (12) is arranged tangentially to the incident flow tube (10).
6. Mill classifier according to one of the preceding claims,
   characterized in that
   the guide plate (11) facing the coarse material particles (32) from the dynamic classifier part (7) is at least partly made from a wear-resistant material or has a wear-resistant coating.
7. Mill classifier according to claim 5 or 6,
   characterized in that
   the plate (12) has an almost identical construction to the guide plate (11).
8. Mill classifier according to claim 5 or 6,
   characterized in that
   for a widening flow channel (13), compared with the guide plate (11), the plate (12) is located at the incident flow tube (10) with a different setting angle.
9. Mill classifier according to one of the claims 5 to 8, characterized in that
   the guide plate (11) and the plate (12) are almost in engagement with rotor-side edges areas (21, 22).
10. Mill classifier according to one of the preceding claims,
    characterized in that
    the rotor strips (7) of the strip rotor (16) have a Z-shaped constuction and on the guide vane side have a rounded leg (27).
11. Mill classifier according to one of the preceding claims,
    characterized in that
    the strip rotor (16) is constituted by a double cone rotor (16) of a centrifugal classifier having inclined rotor strips at a lower cone and being retooled such that the rotor strips are vertically arranged to a cylindrical rotor area (8),
    and that the strip rotor (16) has in addition to the cylindrical rotor area (8) a conical rotor area (18), which is made hydraulically ineffective.
12. Mill classifier according to claim 11,
    characterized in that
    the retooled double cone rotor (16) has rotor strips (7), which are virtually vertical above the conical rotor area (18) and form the cylindrical rotor area (8) and that the conical rotor area (18) is covered by a cover cone (28).
13. Mill classifier according to claim 11 or 12,
    characterized in that
    the rotor strips (7) of the cylindrical rotor area (8) for a cylindrical envelope (40) coaxial to the guide vane ring (4) have a height corresponding to the height of the guide vanes (5) of the static classifier (4).
14. Mill classifier according to one of the claims 1 to 10,
    characterized in that
    a rod basket classifier rotor (19) with vertical rotor strips (7) is used as strip rotor (16).
15. Mill classifier according to one of the preceding claims,
    characterized in that
    a classifier housing upper part (25), a bearing collet (24), a drive positioned above the bearing collet (24), a driving shaft (26) and a classifier housing (23) are used, whereby the classifier housing (23) tapers conically over the height of the guide vane ring (4).

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