Patent Application
20160223261
1. Field of the Invention
The invention relates to the manufacture of cement clinker in a cement clinker line, and in particular to a plank type conveyor for cooling and conveying cement clinker from a rotary kiln to a clinker outlet of the conveyor.
2. Description of Relevant Art
In cement clinker manufacturing, the cement clinker, briefly clinker, is burnt and sintered in a rotary kiln. The clinker is unloaded from said kiln via a clinker distribution system onto a conveyor grate floor of a clinker cooler. On the grate floor, the clinker forms a layer, as well referred to as clinker bed. The clinker bed is cooled and transported (conveyed) to a clinker outlet of the cooler, e.g. via a crusher for further processing, e.g. milling. The construction of the grate floor is essential as on the one hand cooling air has to be inserted into the clinker bed via the grate floor and on the other hand clinker drop through the grate floor has to be avoided. In addition the clinker has to be transported and the grate floor must withstand the high clinker temperatures and the abrasion caused by moving the clinker over the grate floor be it mechanically or pneumatically.
There are three types of currently used clinker coolers, namely, the first type are stepped grate coolers as disclosed e.g. in U.S. Pat. No. 8,397,654.
The second type of coolers have an essentially plane and static grate surface on which the clinker resides. In the surface are aeration slits for cooling the clinker by injecting a cooling gas into the clinker residing on the surface. The static plane grate surface often has box like pockets and the aeration slits are in the bottom of the pockets. In use the pockets are filled with clinker that is blocked by the pockets' side walls from sliding over the grate, i.e. the pockets' bottoms to reduce wear of the grate surface. Clinker transport takes place by shearing the clinker bed, i.e. the upper part of the clinker bed slides over the clinker in said pockets. To this end clinker pushers are installed between the pockets and reciprocate above the pockets' side walls. This type of coolers are commercially available under the name “Polytrack”, the latter being displayed in DE 10 2006 037 765. The Polytrack cooler has longitudinal tracks below longitudinal slits between rows of the pockets. The tracks support reciprocating horizontal pusher plates covering the longitudinal moving slits between the pockets. The pusher plates have pusher ribs extending vertically and perpendicular to the conveying direction and form pockets for several layers of clinker grains. When moving the pusher plates, the clinker in the pockets moves with the pusher plates. Conveying is obtained by moving the pusher plates forward commonly and retracting them separately.
The third type are coolers which have planks extending in parallel to the conveying direction as disclosed e.g. in DE 10 2010 055 825A, U.S. Pat. No. 8,132,520 or EP 1 475 594 A1. Here, we focus only on this third type of clinker cooler, as well referred to as “plank type cooler”.
A plank type cooler typically has a multitude of planks, one besides of the other with moving gaps in between. The longitudinal orientation of the planks is parallel to the conveying direction and the planks are individually moved forward and backward, i.e. reciprocated parallel to the conveying direction to obtain a forward movement of the clinker bed residing on the up facing surface of the planks. A moving gap is a gaps between adjacent, i.e. neighbored planks thereby enabling the movement of one plank relative to the other plank. Such a plank type cooler is disclosed in U.S. Pat. No. 8,132,520 (the disclosure of which patent document is incorporated herein by reference): The clinker is loaded on a plane up facing surface of the planks, extending parallel to the conveying direction. The clinker transport can be obtained by moving at least some neighbored planks forward commonly, i.e. at the same time and retracting them separately, i.e. one after the other, accordingly there are moving gaps between the planks. The cooling air is inserted via the moving gaps into the clinker bed, to thereby heat the cooling air and cool the clinker.
DE 10 2010 055 825 A1 suggests a different type of plank type clinker cooler: Each plank reciprocates and supports box like inlets, being aligned along the plank. The box like inlets have cooling slots for aeration of the clinker. A layer of clinker remains in the box like inlets while transporting the clinker bed to thereby reduce abrasion of any mechanical part of the planks. In addition, the planks support a small amount of protrusions which may be wedge like or plow like. These protrusions shall periodically churn or circulate the clinker bed, to thereby induce a circulation in its lower part. This circulation shall reduce the formation of air channels in the clinker bed, which are unfavorable for heat recuperation.
EP 1 475 594 A1 discloses a further plank type clinker cooler. The cross sections of the planks resemble an open box like channel and clinker aeration is provided by ventilation slits in the bottom of the channel. The moving gaps between adjacent planks are sealed to avoid clinker drop through. To reduce the conveying speed single planks may be static.
The object of the invention is to provide a conveyor floor for bulk material like cement clinker with reduced manufacturing costs.
The invention is based on the observation that a significant part of the costs for a plank type cooler or conveyor floor is due to the driving and suspension mechanism for reciprocating the planks.
Clinker transport is effected by exerting forces on the clinker bed. According to the invention, clinker transport is obtained preferably only by exerting forces on the lowest clinker layer(s) of the clinker bed on the conveyor floor. Upper Clinker layers not being in direct contact with the conveyor floor will follow—maybe with some slip—due to the internal coefficient of friction between the layers.
The driving force may be exerted to the bottom layer of the clinker bed only by a profiled grate surface, i.e. a conveyor floor surface with a structured surface. The structured surface may for example be formed (i.a.) by a multitude of faces being at least approximately (±45°, preferably ±30°) orthogonal to the horizontal plane and of e.g. 10% to 50% of the height of the mean grain diameter. Throughout the application it is assumed for simplicity only that the conveying direction is parallel to the horizontal. However, the true conveying direction may of course be slightly upwards or downwards. The ‘horizontal’ is so to speak only a reference plane being defined by the conveyor floors longitudinal and cross axes. Further it should be noted that the conveying direction is the “intended” conveying direction, pointing parallel to the planks longitudinal axis towards the bulk material outlet.
The height of the at least approximately orthogonal faces of the grate surface may be reduced even further to e.g. 1% to 10% of the mean grain size so that the faces will be of the height or size of fluidizable fines, which in the presence of cooling air jets will be swept up. Such profiled surfaces may be characterized by its coefficients of friction just like polished surfaces. However, different from polished surfaces the coefficient of friction must be measured at least over a section of the plank that is representative for the plank's surface structure. So to speak not the theoretical, only material dependent, coefficient of friction is addressed here, but a macroscopic coefficient of friction that accounts not only for the materials but as well for the surface structure of the materials.
The conveyor floor comprises at least a multitude of longitudinal planks each with an up-facing surface as rest for bulk material like, e.g. cement clinker. Of course other bulk or granular material may be conveyed as well. However, for sake of simplicity the conveyor according to the invention is explained with respect to cement clinker only. The planks of the conveyor floor extend in parallel to the conveying direction. Transverse to the conveying direction, the planks are arranged one besides of the other with moving gaps in between. To reduce clinker drop through the grate, the width of the moving gaps may be much smaller than the width of the planks, e.g. smaller than 1/10th of the mean width of the planks, preferably smaller than 1/100th of the mean width of the planks. The moving gaps may be used as cooling slits, i.e. for blowing a coolant, e.g. air into the bed of bulk material residing on the planks. In particular in this case the width of the moving gaps should be smaller than the diameter of clinker grains that may not be transported by the cooling air out of the moving gaps, i.e. that are too big to been blown out of the moving gaps. The conveyor floor further comprises a support structure for supporting and reciprocating individual planks and/or groups of planks, to thereby convey clinker in the conveying direction. Preferably, at least a section of at least one up-facing surface of at least one of said planks has a direction dependent frictional coefficient, this means that the frictional coefficient Cf for clinker moving relative to the respective plank in the conveying direction is lower than the frictional coefficient Cb for clinker moving relative to the respective plank against the conveying direction (in other words ‘backwards’). The mean of the backward frictional coefficient Cb of the planks forming the conveyor floor is more than 1.5 times, preferably more than two times, more preferably more than three times the mean of the frictional coefficient Cf, i.e.
wherein
The ratio
can be obtained e.g., by planks having wedge like protrusions and/or with a shingled surface as rest for the bulk material. The wedge like protrusions and/or the shingled surface area of the planks cover preferably more than half of the conveyor floor's surface. Preferably, at least one of the planks has on its up facing surface at least one series of consecutive protrusions to thereby enhance the ratio of the mean coefficients of friction
In theory the coefficient of friction is determined by sliding a polished plane surface over another polished plane surface. Here, the situation is different, the bulk material, e.g. clinker slides over a plank surface. The different coefficients of friction are thus obtained by structuring the planks' surfaces, as explained below in more detail. When referring to the coefficient of friction the dynamic friction is addressed. Relevant is the mean friction between the respective planks and the bulk material, in other words the friction that is measured by moving the bulk material over the real plank and a not over an idealized surface. The mean coefficient of friction between a plank and a bulk material like clinker can be determined very easily, by simply sliding the plank or a representative section over (e.g.) a clinker bed with different loads on the plank and measuring the drag force for moving the plank with a constant speed over the clinker. The speeds should be similar to the relative speeds between the bulk material and the planks when conveying the bulk material. In this case the normally up facing side of the plank is of course turned downwards to face the clinker as it would if installed in a conveyor floor.
A very simple but efficient possibility of realization of a direction dependent frictional coefficient is to use planks having wedge like protrusions. Thus, each protrusion has a front facing side and a rear facing side, each having a slope. The mean slope of the front facing side is steeper than the mean slope of the rear facing side. The front facing side is so to speak the butt end of the wedge being directed (at least approximately, i.e. ±45°, preferably ±30°) in the conveying direction and the rear facing side is in the example a wedge surface pointing (with the wedge edge) in the opposite direction. The complementary wedge surface is only imaginary and part of the horizontal. The front and rear facing sides may meet at a crest like edge. For example, the protrusion may have a longitudinal section resembling for example a saw tooth, a triangle or a wedge. The steeper side of the protrusion is the front facing side and the gently sloped side is the rear facing side. In other words the terms front facing and rear facing sides do not imply that these sides are orthogonal to the conveying direction, although the front facing side may be at least approximately orthogonal (±45°, preferably ±30°) to the conveying direction. The clinker grains residing directly on the respective plank may thus climb over the protrusions when retracting said plank. When pushing the plank in the conveying direction (i.e. forward) the clinker grains in the optimum case stick to the plank, or at least slide less as if retracting the plank.
In a particular preferred embodiment, the front facing side or at least its section along the conveying direction (longitudinal section) is plane and orthogonal to the horizontal or inclined in the conveying direction. In case of a curved longitudinal section this holds preferably for the mean slope of the front facing side's longitudinal section.
A cooling gas may be injected via the moving gaps into the clinker bed. The moving gaps thus have two combined functions: the first is enabling a movement of neighbored planks relative to each other and the second is to serve as coolant channel for injecting a cooling gas, e.g. air into the clinker bed residing on the conveyor floor's surface. In addition, the coolant flow through the moving gaps prevents clinker drop through the conveyor floor. The moving gaps are preferably inclined towards the horizontal to thereby attach the coolant flow to the conveyor floor's surface. Accordingly the narrow facing sides of the planks are the boundaries of the moving gaps and are preferably inclined towards the horizontal. This enhances homogenous clinker cooling and lifting of the fines to the upper region of the clinker bed. In other words: In a cross sectional view, preferably each moving gap has a left and a right boundary, both being formed by a narrow side of two neighbored planks. The narrow sides forming the moving gap face each other.
Preferably, one of these narrow sides evolves continuously curved into the up facing side of the respective plank and thus into the conveyor floor's surface. It is sufficient to approximate the continuous curvature by a polygonal line (as seen in the cross section). In case of a substantially plane narrow side, the narrow side preferably forms an obtuse angle with the up facing side of the plank to thereby evolve so to speak semi continuously into the up facing side of the plank. In all three cases, the air flow will follow the (semi) continuous curvature and so to speak attach to the plank's up facing side until it is deflected by clinker grains. This narrow side so to speak forms a lower coolant channel boundary. The other narrow side of the respective plank is preferably complementary to said (semi) continuously evolving narrow side. This other narrow side preferably forms an edge with the up facing side of the respective plank and is so to speak the ‘upper’ coolant channel boundary of the next moving gap.
On the other hand, if one injects the coolant via inclined moving gaps into the clinker bed, the coolant exerts a force on the clinker grains towards the conveyor floor's left or right boundary (depending on the direction of inclination of the moving gaps). This may lead to a unwanted lateral clinker transport and an inhomogeneous clinker distribution on the conveyor floor. In a preferred embodiment, the front facing side of at least one of the protrusions is inclined (preferably between 0.1 and 45°, more preferably between 0.1 and 30°) to the left or to the right, i.e. towards one of the conveyor floor's side boundaries. More precisely the front facing side of (at least one of) the protrusions may be inclined towards the narrow side that evolves at least semi continuously into the plank's up facing side and thus the conveyor floor's surface. With respect to a protrusion's front facing side being perfectly orthogonal to the intended conveying direction, the inclination towards the narrow side that evolves at least semi continuously into the planks up facing side corresponds to a rotation along a vertical axis. Such inclination compensates the clinker movement towards the conveyor floor's respective side boundary and an at least almost perfect clinker transport parallel to the longitudinal direction of the conveyor floor may be obtained. As explained already with respect to the coefficient of friction, the protrusions' front facing sides may as well be inclined against the vertical (±45°, preferably ±30°). Starting again from a front facing side being perfectly orthogonal to the conveying direction, this corresponds to rotation along a cross axis of the conveyor floor.
With respect to clinker, it turned out that the height h of the protrusion is preferably significantly smaller than the mean clinker grain diameter. The typical clinker grain diameter is about 1 cm, accordingly the height h of the protrusions is preferably about 1-5 mm. Generalizing one may say that the height h of the protrusion is preferably about half ( 1/10·dm≦h≦1dm, preferably ⅕·dm≦h≦¾dm, particulary preferred ¼dm≦h≦½dm) of the median diameter dm of the clinker grains. For example if a typical clinker grain (typical median of the diameter dm=1 cm) has a diameter of about 1 cm, the height may be e.g. about 2 to 4 mm. Thereby, the transport properties are particularly enhanced. The length lr of the gently sloped rear side of the protrusion is preferably about 2 to 50 times, more preferably 2 to 10 times the median of the diameter of the grains, i.e. 2·dm≦lr≦50·dm more preferably 2·dm≦lr≦10·dm. For typical clinker, the length lr is thus preferably about 2 to 10 cm, particularly preferred about 3 cm (±15%) so that clinker grains of nearly all sizes will sink to the slope in between two crests.
When conveying clinker, one distinguishes between clinker grains and so called fines. Fines are swept away and levitated by the typical air stream in a clinker cooler which has a typical velocity of very roughly about 1 m/s (±50%) in the lower and thus colder region of the clinker bed and up to very roughly 4 m/s (±35%) in the upper regions of the clinker bed, where the air expands due to the heat being transferred from the clinker to the air (or any other cooling gas). The grains, in contrast, are bigger and remain supported by the conveyor floor or grains residing thereon. In other words fines are levitated by the cooling gas whereas grains still exert a resulting downward force on the conveyor floor and/or other grains residing thereon.
The above explained ratio of the forward and backward frictional coefficient significantly enhances the clinker transport and thus enables to simplify the construction of the conveyor floor:
A first possibility to reduce the cost is to group the planks in at least two groups A, B where the planks of each group are driven synchronously and can thus be coupled. Accordingly, the planks of group A, briefly referred to a ‘planks A’ are driven in common and the planks of group B, briefly referred to a ‘planks B’ are driven in common as well (but preferably independent from the ‘planks A’). Driving groups of planks in common opens the possibility of reducing the number of actuators, for example to the number of groups of reciprocating planks. Additionally, the grouped planks may be suspended group wise, thereby further reducing the costs.
For example the grate floor may resemble a pattern |A B . . . A B|. Where the letters A, B symbolize planks of the respective group and “|” the cooler or conveyor boundaries. In this case, preferably, the planks of both groups A, B are moved forward simultaneously, but are retracted one group after the other. Grouping of the planks enables to reduce the number of longitudinal bars, actuators, cross beams and suspension units and thus the costs.
Preferably, at least one group of planks does not move; in other words the planks of the respective group are mounted to the static part of the support structure. The planks of this static group are referred to as planks of group C or simply planks C (C=constant). Possible pattern could thus be e.g. |C A B C . . . A B C| or more preferably |A C B C A . . . C A C B C| or even more preferred |C A C A . . . A C A C| as explained below in more detail. By introducing the static, i.e. constant planks C, the constructional effort and thereby the costs are further reduced. While the patterns like |C A B C . . . A B C| and |C A C A . . . A C A C| require two separately supported and driven systems the direction dependent coefficients of friction enable patterns like |C,A,C,A,C . . . A,C| which requires only one movable support and drive and thus offers significant savings.
As already set out above, the planks' surfaces are preferably structured to have directional coefficients of friction. In other words, the mean coefficient of friction
The situation of a reciprocating plank next to a static plank can be understood as follows: When pushing a reciprocating plank forward, the lowest layer of clinker grains on the plank so to speak sticks or engages to the plank and moves forward with the plank, due to the relatively high mean coefficient
Briefly summarizing: When retracting a plank, the clinker bed moves relative to the retracted plank in a forward direction and due to the lower directional coefficient of friction (Cf applies); the clinker grains of the lowest layer of clinker grains slide or slip over the plank (at least easier than in the opposite direction). The clinker on the retracted plank is held in its position relative to the static support structure by the engagement with clinker grains of static planks that in an optimized view stick to their respective plank when pushed backward by the shearing forces as Cb applies.
In this application it is assumed for simplicity only, that the planks of the different groups are of identical dimension and shape. However, differing dimensions are possible as well, if only the ratios of the forces due to friction at forward and backward movement represented either by their profile or their width of the planks is larger than 1.5-2.
The invention is explained with respect to a clinker conveyor. Cooling air or a different cooling gas can be injected into the clinker through cooling slits, e.g. via the moving gaps between neighbored planks, to thereby obtain a clinker cooler for cooling and simultaneously conveying clinker in a conveying direction from a clinker inlet of the cooler to a clinker outlet. Ventilation means may optionally be provided for blowing a cooling gas via the moving gaps for aeration of the clinker bed. The cooling gas can be any gas or a mixture of gases e.g. air and/or carbon dioxide. However, the conveying mechanisms explained above can be used for any kind of bulk material. In other words, depending on the material to be conveyed one may omit (or seal) the cooling slits.
Subsequently and preceding, the invention is explained with respect to a clinker cooler; however the invention is not limited to clinker coolers but can be applied in any type of walking floor conveyors.
For example, the planks can be grouped in only two groups of planks, namely planks of first group A and planks of a second group C. The planks of the first group A are suspended and driven to reciprocate preferably with the same phase, amplitude and waveform. A suspension, for example the one disclosed in U.S. Pat. No. 6,745,893 enables the reciprocating movement of all planks of the first group A. In addition, the planks of the first group A can be driven by only a single drive, e.g. a hydraulic cylinder, to which they are coupled. The planks of the second group C are preferably mounted to a static support, i.e. they do not reciprocate and accordingly the drive and the suspension for planks of group C may be omitted yielding significant savings.
Preferably, the planks of the first group A are neighbored to planks of the second group C, forming a pattern of planks reading |A, C, A, . . . A, C, A,| or |C, A, C, . . . , C, A, C| where the vertical lines or bars | symbolize the boundaries of the grate floor defining the grate floor's width and A and C symbolize a plank of the respective group. The commas represent moving gaps between the planks. So to speak the vertical lines represent the left and right border of the grate floor, where left and right is relative to the conveying direction. Particularly preferred is the second pattern |C, A, C, . . . C, A, C|, because the planks next to the boundaries do not reciprocate and thus the connection of the boundaries to the grate floor is simple as there is no relative movement. The boundaries are typically board like walls.
In an alternative embodiment the planks may be grouped in exactly three groups of planks, wherein the planks forming the first group A of planks are driven to reciprocate in parallel to their longitudinal axis and thus the conveying direction in a common phase, preferably with the same amplitude and waveform. The planks forming the second group B of planks (briefly “planks B”) are suspended and driven to reciprocate in parallel as well and with a common phase, i.e. they reciprocate parallel to their longitudinal axis and thus to the conveying direction. Preferably, the planks of group B are moved forward, i.e. in the conveying direction, simultaneously with the planks of the first group A, but moved backwards non-simultaneously with the planks of the first group A. The planks of the group B may be suspended and driven similar to but independently form the planks of group A. The planks C of the third group C are mounted to a static support structure. For example the planks form a pattern |C, A, C, B, C, . . . , C, A, C, B, C,| or |C, B, C, A, C . . . C, A, C, B, C|, where A, B, C denote a plank of the respective group and the | symbolize the boundary of the grate floor as explained above. Here the number of fixed planks is the same as in the example above, but two independent suspension systems are required. This alternative is still cheaper as the prior art conveyors or clinker coolers, because the number of static planks is augmented.
In the following, the invention will be described by way of example, without limitation of the general inventive concept, on examples of embodiment and with reference to the drawings.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
In
The conveyor floor 1 has planks 100 extending in the longitudinal direction (indicated by double headed arrow 3) from the conveyor inlet to the conveyor outlet. The planks 100 are arranged in parallel one besides of the other with moving gaps 20 in between. The moving gaps 20 (cf.
Grate boundaries 30, as well referred to as side walls 30, may be installed to the left and to the right of the planks (
The planks 100 are denominated A, B, C, indicating a group they belong to. The planks 100 of each group A, B, C are mounted to separate cross beams 40. The cross beams 40 carrying the planks of groups A and B are suspended and driven to reciprocate as indicated by the arrow 3. The cross beams 40 supporting the planks of group C are fixed, i.e. they are rigidly mounted to a base, e.g. by some static support structure. The pattern A,B,C as depicted is only an example. Other patterns, or in other words other sequences of groups are as well possible, for example |C,A,C,A . . . C| or |C, B, C, A, C, B, . . . , C| to list only two.
As shown in
In
For a homogeneous aeration of the clinker, the moving gaps 20 are inclined against the vertical. For forming the inclined moving gap 20 each plank has a first narrow side with an inclined upper surface 21 and a second narrow side 22 with a complementary undercut. The upper surface 21 and the second narrow side are preferably parallel. Preferably, the protrusion 10 extends smoothly from the first narrow side as shown in
As shown in
The grate floor in
The overlap portion 16 has a lower surface (down facing surface 17) that is preferably continuously curved from the moving gap's inclination towards the horizontal. The up facing side 18 is gently sloped like the whole rear facing side 14. In other words, the thickness of the overlap portion is preferably continuously reduced until the lower surface 17 and the up facing side 18 meet preferably in an edge 19 or edge like rounding. The edge 19 connects the lower edge of a front facing side 12 of a rearward protrusion with the front facing side 13 of the overlap portion 16.
Conveying is obtained by the conveyor floor of
The planks of group C however are static. In other words they do not reciprocate (relative to the base, defining the reference system). Extended over the whole grate floor the depicted pattern of planks thus reads “ . . . , A,C,B,C,A,C,B, . . . ”, wherein the comma represents moving gaps. The connection to the conveyor floor side boundary is preferably by planks of group C. In this case the pattern reads |C, A,C,B, . . . A,C| or |C,A,C,B, . . . B,C|, wherein the vertical lines | symbolizes the conveyor floor boundary.
It will be appreciated to those skilled in the art having the benefit of this disclosure that this invention is believed to provide a conveyor floor in particular for cooling bulk material like cement clinker or the like. Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be taken as the presently preferred embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims.
In
The conveyor floor 1 has planks 100 extending in the longitudinal direction (indicated by double headed arrow 3) from the conveyor inlet to the conveyor outlet. The planks 100 are arranged in parallel one besides of the other with moving gaps 20 in between. The moving gaps 20 (cf.
Grate boundaries 30, as well referred to as side walls 30, may be installed to the left and to the right of the planks (
The planks 100 are denominated A, B, C, indicating a group they belong to. The planks 100 of each group A, B, C are mounted to separate cross beams 40. The cross beams 40 carrying the planks of groups A and B are suspended and driven to reciprocate as indicated by the arrow 3. The cross beams 40 supporting the planks of group C are fixed, i.e. they are rigidly mounted to a base, e.g. by some static support structure. The pattern A,B,C as depicted is only an example. Other patterns, or in other words other sequences of groups are as well possible, for example |C,A,C,A . . . C| or |C, B, C, A, C, B, . . . , C| to list only two.
As shown in
In
For a homogeneous aeration of the clinker, the moving gaps 20 are inclined against the vertical. For forming the inclined moving gap 20 each plank has a first narrow side with an inclined upper surface 21 and a second narrow side 22 with a complementary undercut. The upper surface 21 and the second narrow side are preferably parallel. Preferably, the protrusion 10 extends smoothly from the first narrow side as shown in
As shown in
The grate floor in
The overlap portion 16 has a lower surface (down facing surface 17) that is preferably continuously curved from the moving gap's inclination towards the horizontal. The up facing side 18 is gently sloped like the whole rear facing side 14. In other words, the thickness of the overlap portion is preferably continuously reduced until the lower surface 17 and the up facing side 18 meet preferably in an edge 19 or edge like rounding. The edge 19 connects the lower edge of a front facing side 12 of a rearward protrusion with the front facing side 13 of the overlap portion 16.
Conveying is obtained by the conveyor floor of
The planks of group C however are static. In other words they do not reciprocate (relative to the base, defining the reference system). Extended over the whole grate floor the depicted pattern of planks thus reads “ . . . , A,C,B,C,A,C,B, . . . ”, wherein the comma represents moving gaps. The connection to the conveyor floor side boundary is preferably by planks of group C. In this case the pattern reads |C, A,C,B, . . . A,C| or |C,A,C,B, . . . B,C|, wherein the vertical lines | symbolizes the conveyor floor boundary.
| Number | Date | Country | Kind |
|---|---|---|---|
| 13181917.9 | Aug 2013 | EP | regional |
This application is a continuation of the currently-pending International Application No. PCT/EP2014/066077 filed on 25 Jul. 2014 and titled “Clinker Cooler” (now published as WO/2015/028217), which designates the United States and claims priority from European Application No. 13181917.9 filed on Aug. 27, 2013. The disclosure of each of the above-identified patent applications is incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2014/066077 | Jul 2014 | US |
| Child | 15053026 | US |
