EP1272803B2 - Cooler and a method for cooling hot bulk material - Google Patents

Description

The invention relates to a method for cooling hot bulk material according to the preamble of claim 1.

For cooling of hot bulk material, such as cement clinker, the bulk material is placed on a cooling gas flow-through cooling grate. During transport from the beginning of the radiator to the radiator end, the bulk material is flowed through by cooling gas and thereby cooled.

Various possibilities are known for the transport of the bulk material. In the so-called sliding grate cooler, the bulk material is transported by movable rows of cooling grates, which alternate with fixed cooling grate rows in the transport direction.

In addition, it is known to provide a fixed aerated by cooling gas ventilation floor for receiving the bulk material, wherein above the ventilation floor conveyor elements are provided for transporting the bulk material. The transport mechanism distinguishes between circulating and reciprocating conveying elements.

In the method according to WO 98/48231 A1 such as DE 878625 the hot bulk material is applied to a fixed ventilation bottom through which cooling gas can flow and transported by means of conveying elements which are movable to and fro above the aeration bottom. The in the DE 878625 described conveying elements are formed by rods which are arranged above a fixed grate and extending in the longitudinal direction parallel to the grate level. The rods are connected to a suitable movement mechanism, which allows a reciprocating movement in the transport direction of the bulk material. In addition, suitable projections are provided on the rods to assist the conveying action.

In contrast to the revolving conveyor elements arises in the reciprocating conveyor elements, the problem that a portion of the bulk material is taken back during the return stroke. However, this disadvantage can be partially offset by a suitable design of the conveying elements. For example, conveying elements have been proposed with a substantially triangular cross-sectional shape, wherein the pointing in the direction of transport end face is formed substantially perpendicular to the transport direction and the rear end face forms an angle between 20 and 45 ° to the ventilation floor. While the forward vertical stroke the substantially vertical face achieves a good conveying effect, the conveying element can be withdrawn in the return stroke by its wedge shape under the bulk material, see, for example DE-4417422-A ,

But even with such an embodiment of the conveying elements, a portion of the bulk material is taken during the return stroke.

The invention is therefore based on the object to improve the method according to the preamble of claim 1 with respect to the conveying effect.

According to the invention, this object is solved by the features of claim 1.

Further embodiments of the invention are the subject of the dependent claim.

In the field of conveyor technology, so-called "pendulum floor conveyors" are already known, in which adjacent, independently movable longitudinal conveyor elements are moved forward and individually backward for good promotion (see. US-A 5,156,259 ). The conveying elements in this case close directly to each other and form in their entirety a closed conveyor bottom, which receives the entire load of the material to be conveyed and does not allow Gutdurchfall. A preferred field of application of such pendulum bottom conveyors are trucks.

Especially with coarse bulk material, the bulk material forms a relatively compact unit, which can be moved in the transport direction in the common forward stroke of the conveying elements. By the different groups of conveying elements are actuated individually and sequentially during the return stroke, due to the friction conditions in the good bed significantly less bulk is taken contrary to the transport direction, as in a common return stroke of all conveying elements.

Each group of conveying elements consists of at least one conveying element or conveying element strand.

In the context of the invention, it is also conceivable that the conveying elements of a group are operated individually, so that they are operated, for example, different speeds and different lengths or with different stroke.

In a first embodiment, the individual groups of conveying elements are provided alternately transversely to the transport direction of the bulk material. In the experiments underlying the invention has been shown that with three groups of conveying elements, which are arranged alternately transversely to the transport direction of the bulk material, the best results can be achieved.

In a second embodiment, the conveyor elements adjacent to the transport direction are arranged such that they are aligned to each phase of the movement sequence offset from each other in the transport direction.

In a third embodiment of the invention, the individual groups of conveying elements are arranged alternately in the transport direction of the bulk material.

Due to the friction conditions in the region of the lateral boundaries of the cooler or procedural reasons, it may be appropriate to the stroke of the conveying elements over the width of the Ventilation floor different lengths form.

Further advantages and embodiments of the invention will be explained in more detail with reference to the description of some embodiments and the drawings.

Fig. 1

eine schematische Längsschnittdarstellung des Kühlers,

Fig.2

eine schematische Querschnittdarstellung gemäß einem ersten Ausführungsbeispiel der Förderelemente,

Fig.3a bis 3d

eine schematische Darstellung des Bewegungsablaufes in der Aufsicht des ersten Ausführungsbeispieles,

Fig.4

eine schematische Querschnittdarstellung gemäß einem zweiten Ausführungsbeispiel der Förderelemente,

Fig.5a bis 5d

eine schematische Darstellung des Bewegungsablaufes in der Aufsicht des zweiten Ausführungsbeispieles,

Fig.6

eine schematische Querschnittdarstellung gemäß einem dritten Ausführungsbeispiel der Förderelemente, und

Fig.7a bis 7c

eine schematische Darstellung des Bewegungsablaufes in der Aufsicht des dritten Ausführungsbeispieles.

In the drawing show

Fig. 1

a schematic longitudinal sectional view of the radiator,

Fig.2

a schematic cross-sectional view according to a first embodiment of the conveying elements,

3a to 3d

a schematic representation of the movement sequence in the plan view of the first embodiment,

Figure 4

a schematic cross-sectional view according to a second embodiment of the conveying elements,

5a to 5d

a schematic representation of the movement sequence in the plan view of the second embodiment,

Figure 6

a schematic cross-sectional view according to a third embodiment of the conveying elements, and

Fig.7a to 7c

a schematic representation of the sequence of movements in the supervision of the third embodiment.

The in Fig. 1 shown cooler 1 for cooling hot bulk material 2 has substantially a fixed, can be flowed through by cooling gas ventilation floor 3 for receiving the bulk material and above the ventilation floor arranged, reciprocable conveying elements 4, 5, 6 for transporting the bulk material. The bulk material 2 is formed for example by cement clinker, which is supplied from a rotary kiln 7 upstream of the cooler. The bulk material passes through an oblique inlet region 8 on the fixed ventilation floor 3 and is transported there by means of the conveying elements 4, 5, 6 in the longitudinal direction through the radiator.

The ventilation floor is designed in a manner known per se and in particular has openings through which the cooling gas flows through the bulk material bed and thereby cools it. The cooling air openings in the ventilation floor 3 are designed so that a sufficient amount of cooling air supplied, but rust diarrhea can be avoided. The cooling air is expediently supplied below the ventilation floor 3. However, in the illustrated embodiments, the air ducts are not shown in detail for reasons of clarity.

The conveying elements are divided into at least two groups, wherein the at least two groups of conveying elements in the transport direction of the bulk material can be actuated separately from one another and counter to the transport direction. The detailed design and the sequence of movement of the conveying elements in a first embodiment will be described below with reference to FIG Fig.2 and 3 explained in more detail.

In this first embodiment, three groups of conveying elements 4, 5, 6 are provided, which are alternately transversely to the transport direction of the bulk material (arrow 9 in FIG Fig.1 ) are arranged. In the illustrated embodiment, six conveying elements are provided across the width of the radiator 1, wherein the conveying elements 4.1 and 4.2 belong to the first group, the conveying elements 5.1 and 5.2 to the second group and the conveying elements 6.1 and 6.2 to the third group. Of course, in the context of the invention, more or fewer conveying elements can be arranged over the width of the radiator.

Each conveying element 4.1 to 6.2 is connected via a carrier element 14.1 to 16.2 with suitable transport mechanisms 17.1 to 19.2. In the illustrated embodiment, 3 slots are provided in the ventilation floor through which the support elements 14.1 - 16.2 are passed.

The transport mechanisms, which are associated with a specific group of conveying elements, can be coupled together for common adjustment of the conveying elements. The reciprocating movement of the conveying elements is realized for example via a hydraulic drive.

With the help of 3a to 3d the sequence of movements of the first embodiment will be explained in more detail below. 3a shows the state after the common forward stroke of all conveying elements 4.1 to 6.2. All conveying elements have been moved in the transport direction of the bulk material (arrow 9) by a length a. The bulk material lying on the ventilation floor and thus also on the conveyor elements is displaced in a corresponding manner.

So that as little as possible bulk material is transported back again during the return stroke of the conveying elements, the conveying elements are reset only in groups or individually. 3b shows the state after the return stroke of the conveying elements 4.1 and 4.2, 3 c the state after the further return stroke of the conveying elements 5.1 and 5.2, while in 3 d Finally, the last group has been reset with the conveying elements 6.1 and 6.2.

As in particular from the Fig.1 and 3 can be seen, several conveying elements are arranged in the transport direction over the length of the radiator. The conveying elements according to the first embodiment ( Fig.2 and 3 ) extend substantially in the longitudinal direction, ie in the transport direction of the bulk material (arrow 9).

In the second embodiment according to the Figure 4 and 5 are again transverse to the transport direction of the Bulk material provided several groups of conveying elements 4.1 to 6.2. The conveying elements differ from the first embodiment substantially in that they extend substantially transversely to the transport direction and are accordingly also supported via two carrier elements (for example 14.1) and connected to a transport mechanism (for example 17.1) or can be connected.

Although the conveying elements according to the second embodiment in the basic position can be aligned transversely to the transport direction, as is the case in the first embodiment, in the second embodiment, adjacent conveying elements are arranged such that after each movement phase, i. after the common forward stroke and offset after each return stroke in the transport direction are aligned with each other.

From the 5a to 5d the arrangement of the conveying elements is shown after each movement phase. 5a again shows the state after the common forward stroke of all conveying elements with a stroke length a. It can be seen that adjacent conveying elements (transversely to the transport direction 9) offset in the transport direction are aligned with each other. After the first return stroke of the conveying elements 4.1 and 4.2 of the first group further results in a staggered arrangement of adjacent conveying elements. In 5c are also the conveying elements 5.1 and 5.2 of the second group and in 5d the conveying elements 6.1 and 6.2 of the third group have been withdrawn.

The second embodiment can reduce the unwanted return transport of the bulk material during the return stroke of the conveying elements even better.

In the Figure 6 and 7 a third embodiment is shown, which differs from the preceding embodiments essentially in that only two groups of conveying elements are provided, which are also provided alternately in the transport direction 9 of the bulk material.

In the illustration according to Figure 6 is the front conveyor element 4.1 aborted at its two end portions to make visible the underlying conveyor element 5.1. To clarify are in the 7a to 7d, only three conveying elements 4.1, 4.2 and 4.3 and only two conveying elements 5.1 and 5.2 of the second group shown.

Each conveying element (for example 4.1) is connected via two carrier elements (14.1) to a transport mechanism (17.1). Conveniently, all conveyor elements of a group are moved via a common transport frame in the illustrated embodiment.

How out 7a can be seen, the forward stroke is again for both groups of conveying elements together with a stroke length a. In Figure 7b is the state after the return stroke of the conveying elements 4.1, 4.2 and 4.3 of the first group shown. After the return stroke of the conveying elements 5.1 and 5.2 of the second group is again the initial state according to 7c reached.

In the context of the invention, it would also be conceivable to set the stroke of the conveyor elements arranged transversely to the transport direction differently in the first and second embodiments. This can be compensated over the width of the ventilation floor resulting differences in the good bed. For example, the friction conditions within the bulk material in the middle of the cooler are different than at the two edge regions. Also, a different stroke length could be exploited for better lateral distribution of the goods in the beginning of the radiator.

For better adaptation of the stroke length to the needs of the respective radiator, the stroke length of the conveyor elements should be designed to be adjustable.

In all embodiments, it is expedient to choose the speed for the common feed stroke lower than for the return movements of the individual groups.

The ventilation floor preferably extends horizontally, but also a downward slope would be conceivable.

The material of the conveyor elements must be selected according to the occurring temperature and the expected wear. For example, welding and casting constructions are possible. In the area of the bushings for the support elements also suitable seals must be provided in order to avoid rust diarrhea.

The embodiments described above are characterized in particular by the fact that the bulk material is not significantly carried along during the return stroke of the various groups of conveying elements. Accordingly, a smaller number of strokes is required for the movement of the bulk material, whereby in particular the wear of the conveying elements or the transport mechanism can be reduced.

Claims (2)

1. Method for cooling hot bulk material, the hot bulk material being deposited on a stationary ventilation floor, through which cooling gas can flow, and being transported by means of conveying elements which are arranged above the ventilation floor and which can be moved back and forth, characterised in that there are used at least two groups (4, 5, 6) of conveying elements which are actuated together in the transport direction and separately from each other counter to the transport direction.
2. Method according to claim 1, characterised in that, after the common actuation of all the groups of conveying elements in the transport direction, only one group of conveying elements is actuated in each case counter to the transport direction until all the groups of conveying elements have been returned.

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