EP1153661A1 - Mill separator - Google Patents

Abstract

The mill classifier has a dynamic sifter part with a ring (4) of guide flaps (5) whose flow channels are divided horizontally and have partial channels (23) for smoothing out the inflow of the rotor strips (7). The channels are divided by horizontal guide devices formed as guide plates (8) fixed on the flaps (5). The plates can be welded uniformly spaced one above the other

Description

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

From DE 36 17 746 A1 is a roller mill with an attached Sifter known, which has a fixed guide flap ring and a rotating concentric one Has lamellar basket. Between the classifier housing and the vane ring is cylindrical Annulus formed, which leads to an increase in speed of the fluid loaded with the regrind to be sifted should lead. The fixed guide flaps of the guide flap ring are for the tangential flow of the rotating Slat basket in the direction of rotation and the slats of the The viewing basket is set in the opposite direction, which results in the viewing result should be improved. By in front of the guide flap trained annulus that down to in the mill is extended by means of a double jacket and the speed increase that can be achieved with it of the fluid should be the flow of the guide flap uniform over the entire height and a premature failure of coarse gravel can be prevented.

A mill classifier is known from EP 0 204 412 B1, its rotating lamella basket from an adjustable Guide vane system is surrounded concentrically. The guide vane system consists of two or more sets of vanes, which are arranged one above the other on stationary rings and are adjustable independently of each other.

The lamella used in the above-mentioned mill classifiers or inguinal rotor usually has a number of ledges which is at least twice as high as the standard viewers, which has a conical ledge rotor attached to a double cone rotor, inclined Have visible strips.

To reduce the associated, relatively high manufacturing costs already became a sharp separator proposed (German patent application 199 61 837.2), which the advantages of a slat rotor in terms of suspension and storage and especially in terms of number the rotor strips takes over and with the help of a guide flap ring allows a purely dynamic sighting. The guide flap has adjustable and flow-optimized Guide flaps, which one ascending from the mill Grist fluid flow to a tangential to radial Inflow of the rotor strips, which are vertical and not are arranged more obliquely and a radial dimensioning exhibit, compels.

A selective separation is carried out without an upstream one static sighting through flow-optimized guide flaps reached, which is a rounded leading edge and at least have a baffle and opposite the rotor strips of the inguinal rotor can be adjusted that a parallel flow without constriction at the Outflow or an expanding outflow with diffuser effect sets. The proposed sharp separator advantageously has not only rotor strips as in LOESCHE centrifugal / basket sifters of the LKS type, but also its classifier housing and classifier top, drive and drive shaft on. The space for the ascending regrind fluid flow narrows over the height of the guide flap, causing the particle flow into the flow channels of the guide flap ring is accelerated into it.

It is known that in a roller mill classifier, which is integrated in the roller mill or on the mill housing sits, due to the regrind particles of the two-phase mixture their sluggishness have a tendency almost to the top of the classifier to pour. From there the particles are due to the drag force of the fluid generated by the mill fan to Redirected axis of rotation of the classifier. Signs of wear the guide flaps prove that the particle concentration in the upper area of the guide flaps is particularly high and one uniform radial speed over the height of the rotor bars cannot be reached.

The invention has for its object to provide a mill sifter for an ascending regrind-fluid mixture, in particular a roller mill sifter, which ensures a high level of selectivity and an equalization of the inflow of the rotor strips over their height at comparatively low production costs.

According to the invention the object is achieved by the features of the claim 1 solved. Practical and advantageous configurations are in the description of the figures and in the dependent claims contain.

The invention is based on the basic idea, one as possible uniform radial speed over the height of the Rotor strips through a horizontal division of the flow channels of the static guide system. tries have shown that an arrangement of horizontal intermediate rings on the inguinal rotor to no change in the loading the upper areas of the rotor ledges. A horizontal division made according to the invention in the area of the guide flap ring, such that each of two flow flaps formed flow channels in sub-channels surprisingly, not only leads to being divided an equalization of the radial component of the fluid about the height of the rotor strips, but also to an even of the particle flow over the height of the rotor bars and an improved selectivity of the sighting.

It was found that by a horizontal division the flow channels of the guide flap ring into several, sub-channels arranged one above the other significantly reduced Particle concentration in every area of the rotor bars can be achieved while using conventional flow channels without horizontal dividing or guiding devices an increased exposure to the upper rotor strip areas is recorded.

By dividing the flow channels of the guide flap ring achieved reduction of the vertical component with equalization of the radial component of the particle flow and the associated equalization of the particle flow about the height of the rotor strips can with a better and faster drainage of one in the visual space between the rotor strips and the guide flap ring Semolina cloud to be explained. With a concentrated supply of particles in the upper area of the guide flap ring also the ingot rotor in a comparable range applied to its upper end. In the visual space between the inguinal rotor and the guide flap ring occurs relatively high concentration of oversized grain rejected by the rotor in Form of a semolina cloud. This semolina cloud happens under Gravity affects the view space or view gap of up and down over its entire height before entering the flow-reduced semolina cone below the guide flaps falls. As it passes through the viewing slit, the Semolina cloud, however, constantly from the fluid coming from the grinding room upwards and through the flow channels of the guide flap ring flows, blown again. With flow channels of the guide flap ring without a horizontal division this blowing occurs with a clear vertical Flow component in the flow channels of the guide flaps, which is directed upwards and only slightly inwards is. However, this vertical flow component hinders considerably the free fall of the concentrated semolina cloud. With the help of the horizontal guide devices according to the invention in the flow channels of the guide flap ring the vertical flow component is reduced or switched off and the radial flow component relative to Overall speed increased, so that a blow on the Semolina cloud upwards no longer occurs or to a minimum is reduced and an unimpeded drainage of the now equalized semolina cloud can be made down.

Due to the unimpeded drainage from the inguinal rotor rejected coarse particles is by the invention horizontal division of the flow channels of the guide flaps achieved an improvement in the separator's sharpness. The fanned out over the sub-channels formed Feeding the particle stream from the guide valve system to the Rotor strips leads to a reduction in the specific Rotor load as it has existed in the upper rotor area. While according to the known prior art concentrated stress on an upper area of the Viewing strips occur, are in the invention Mill sifter with the rotor strips over their entire height an approximately equal mass flow of particles, so that there is a lowering of the maximum specific groin stress of the groin rotor comes.

It is advantageous to have a horizontal division Flow channels with the help of guidance devices, in particular horizontal baffles, which are spaced one above the other can be arranged to perform.

The horizontal guide plates are expediently attached to the Guide flaps attached, for example welded on. To one Counteracting wear of the horizontal guide plates, it is recommended that the baffles at least on their To design the inflow side to be wear-resistant and e.g. with a wear-resistant material, armor or a coating to provide.

In a particularly simple and inexpensive training are the horizontal guide plates at an even distance attached to each other on the guide flaps.

Basically, it is useful to set the distances between the Select baffles so that the flow resistances of the Grist-fluid mixture over the entire, horizontally divided Height of the flow channels of the guide flap ring remains approximately constant.

Depending on the regrind to be sifted and the required Fine goods, it can be advantageous to use the horizontal Baffles with an up or down to arrange reducing distance.

With guide flaps, which are fixed and not pivotable to one Guide flap can be arranged horizontally Baffles each on two adjacent baffles Flow channel fixed, in particular welded become.

For guide vane rings with adjustable guide vanes it is advantageous to use the horizontal baffles to be attached to the guide flaps on the fly. If the baffles horizontal only on one side of the guide flaps are arranged, it is changeable angular adjustment of the guide flaps makes sense, the guide plates to be designed such that an adjustment distance to the neighboring Guide flap is present.

In a further training variant, the horizontal ones Baffles fixed on both sides of a baffle, where both baffles are the same or different May have width.

For an effective division of the flow channels of the Guide flap it is appropriate to use the horizontal To form guide plates of two adjacent guide flaps in such a way that they are with their free edge areas overlap. The attachment of the overlapping baffles on the adjacent guide flaps should be done in such a way that they are only slightly in the overlap area Distance, but adjustable, one above the other.

For mill classifiers with flow-optimized guide flaps, which, for example, according to the German patent application 199 61 837.2 are trained, it is appropriate to use the horizontal Baffles on the vertical baffles of the baffles to fix.

In a further training variant, the horizontal Subdivision of the flow channels of the guide flap ring with With the help of horizontal guide rings or ring segments become. The horizontal guide rings or ring segments can then on the leading edges, for example inflow pipes, the flow-optimized guide flaps are attached. An adjustment of the guide flaps is done by horizontal Recesses which are complementary to the guide rings or Ring segments, for example, be slit-like can, guaranteed.

Trials have shown that a selective separator according to the German patent application 199 61 837.2 by the invention divided flow channels of the guide flap ring can be further optimized. Through flow simulations could be demonstrated that by horizontal Baffles in the guide flap ring are a considerably stronger radial component the flow lines is reached and not just a gas flow, but also a particle flow experiences a stronger redirection and the supply of particles is evened out over the height of the classifier rotor.

Fig. 1

einen erfindungsgemäßen Mühlensichter;

Fig. 2

einen ausschnittsweisen Horizontalschnitt des erfindungsgemäßen Mühlensichters gem. Fig. 1

Fig. 3

eine ausschnittsweise Ansicht eines von zwei fest angeordneten Leitklappen gebildeten Strömungskanals mit horizontalen Leitblechen und

Fig. 4

eine ausschnittsweise Ansicht eines von verstellbaren Leitklappen gebildeten Strömungskanals mit horizontalen Leitblechen.

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

Fig. 1

a mill classifier according to the invention;

Fig. 2

a fragmentary horizontal section of the mill classifier according to the invention. Fig. 1

Fig. 3

a fragmentary view of a flow channel formed by two fixed flaps with horizontal baffles and

Fig. 4

a fragmentary view of a flow channel formed by adjustable baffles with horizontal baffles.

Fig. 1 shows a roller mill classifier 2, which in a Rolling mill (not shown) integrated or on this can be put on. The roller mill classifier 2 is a Sharp separator, which is a rod basket classifier with an upstream guide valve system acts. The roller mill classifier 2 essentially has Housing 30, an upper housing part 31 with outlet connection for Fine goods 34, a strip rotor 6 with vertically arranged Rotor strips 7 and one concentric to the strip rotor 6 arranged guide flap ring 4, between which a Visible space 17 is formed.

One in a swirl flow from a roller mill nozzle ring (not shown) upwardly flowing regrind-fluid mixture 3 reaches the mill classifier 2, which is located in the Area of the guide flap ring 4 tapers upwards. The Rotor strips 7 of the cylindrical lead rotor 6 have almost the same height as the guide flaps 5 of the guide flap ring 4 on.

The guide flaps 5 of the guide flap ring 4 are flow-optimized trained and can for a tangential up radial outflow can be adjusted about a vertical axis 9 (see also Fig. 2). To reach the entire height uniform flow against the rotor strips 7 and a to achieve improved separating effect of the mill classifier 2, are 4 horizontal guide devices in the area of the guide flap ring 8 arranged. As horizontal guidance devices are baffles 8 in a largely horizontal orientation attached to the guide flaps 5. In the present Exemplary embodiments are five horizontal baffles each 8 each formed by two guide flaps 5 Flow channels 13 arranged and form six sub-channels 23 for a fanned inflow of the rotor strips 7.

The flow channels 13 and partial channels 23 are shown in the figures 2 to 4, in which training variants of the horizontal Guide devices or guide plates 8 and their arrangement shown in the area of the guide flap ring 4 are.

Fig. 2 shows a plan view of a section of a horizontal section through the mill classifier 2. On a base plate 18 are adjustable, flow-optimized guide flaps 5 arranged to a guide flap ring 4 and surrounded a strip rotor 6 concentric. The rotor strips 5 of the strip rotor 6 can be used as Z strips according to the lower Part of Fig. 2 or as radially aligned flat bars of less radial extension than the Z-bars be (see upper part in Fig. 2).

The guide flaps 5 each have an inflow tube as a rounded one Leading edge 10 and a vertical baffle 11 on, which is tangential to the leading edge 10 with the help fasteners 16, e.g. Mounting flanges, is attached. The guide flaps 5 are vertical Axis 9 adjustable and form flow channels 13 with one Diffuser effect. It is based on the previously cited German Patent application 199 61 837.2 referenced which component of the present application.

The horizontal subdivision of the flow channels 13 arranged horizontal baffles 8 are for better Overview in Fig. 2 only in every second flow channel 13 drawn.

A flow channel shown approximately in the middle of FIG. 2 In a first variant, 13 has a horizontal one Baffle 8, which on the vertical baffles 11th the adjacent guide flaps 5 is welded on. Such Arrangement of the horizontal baffles 8 requires one fixed arrangement of the guide flaps, which is therefore not adjusted can be (see also Fig. 3).

In flow channels 13, which in the detail according to FIG. 2 Shown above and below are horizontal baffles 8 each formed on both sides of the guide flaps 5 and overlap in an overlap area 14 Training variant, the guide flaps 5 for a required tangential to radial outflow adjusted become.

Fig. 3 shows a partial view of the middle flow channel 13 according to arrow A of FIG. 2, but with fixed Guide flaps 5. The guide flaps 5 are on a base plate 18 welded and have superposed, horizontal baffles 8, which the flow channel 13 divide into several subchannels 23. The lower inflow sides 15 of the horizontal guide plates 8 are wear-resistant educated.

FIG. 4 shows a partial view according to arrow B in FIG. 2 again and shows a flow channel 13 which is pivotable, flow-optimized guide flaps 5 are formed is. To ensure the adjustment of the guide flaps 5, are the horizontal baffles 8 on both sides of the Guide flaps 5 and the vertical not shown here Baffles 11 attached and with an adjustment distance 12th to the respective adjacent guide flap 5. To one to achieve efficient subdivision of the flow channel 13, overlap the horizontal guide plates 8 free edge areas in an overlap area 14. The horizontal guide plates 8 are so on the guide flaps 5 or their vertical guide plates 11 attached, in particular welded on that with a low Distance above one another.

Claims (14)

Mill classifier for an ascending regrind-fluid mixture, in particular roller mill classifier, with a dynamic classifier part, which is designed as a strip rotor (6) and has rotor strips (7), and with a guide vane ring (4) as a static guide device, which guide vanes (5) and has flow channels (13) formed between them and concentrically surrounds the inguinal rotor (6) to form an annular viewing space (17),
characterized in that the flow channels (13) of the guide flap ring (4) are subdivided horizontally and have sub-channels (23) for uniformizing the flow against the rotor strips (7). Mill classifier according to claim 1,
characterized in that horizontal guide devices (8) are arranged to subdivide the flow channels (13) of the guide flap ring (4). Mill classifier according to claim 2,
characterized in that the horizontal guide devices are designed as horizontal guide plates (8) and are attached to the guide flaps (5). Mill classifier according to claim 3,
characterized in that the horizontal guide plates (8) are welded to the guide flaps (5). Mill classifier according to claim 3 or 4,
characterized in that the horizontal guide plates (8) are arranged one above the other at a uniform distance. Mill classifier according to claim 3 or 4,
characterized in that the horizontal baffles (8) are arranged with an increasing or decreasing distance. Mill classifier according to one of claims 3 to 6,
characterized in that the horizontal baffles (8) are each attached to two baffles (5) of a flow channel (13), which are non-adjustable. Mill classifier according to one of claims 3 to 6,
characterized in that the guide flaps (5) are adjustable about a vertical axis (9) and the horizontal guide plates (8) are fastened with an edge region on one side of the guide flaps (5). Mill classifier according to claim 8,
characterized in that the guide flaps (5) are flow-optimized for a tangential to radial flow against vertically aligned rotor strips (7) of a cylindrical strip rotor (6) and have at least one vertical guide plate (11) and that the horizontal guide plates (8) are at least on the vertical guide plates (11) of the guide flaps (5) are attached. Mill classifier according to claim 8 or 9,
characterized in that the horizontal guide plates (8) are formed with an adjustment distance (12) to the adjacent guide flap (5). Mill classifier according to one of claims 7 to 10,
characterized in that the horizontal guide plates (8) are fastened on both sides of a guide flap (5). Mill classifier according to claim 11,
characterized in that the horizontal guide plates (8) arranged on both sides of the guide flaps (5) are formed with an overlap area (14). Mill classifier according to claim 12,
characterized in that the horizontal guide plates (8) arranged on both sides of the guide flaps (5) are arranged such that they lie one above the other in the overlap region (14) with a small distance. Mill classifier according to one of claims 3 to 13,
characterized in that the horizontal guide plates (8) are designed to be wear-resistant at least on their upstream side (15).

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