COOLER FOR COOLING HOT PARTICULATE MATERIAL

The present invention relates to a cooler for cooling hot particulate material which has been subjected to heat treatment in an industrial furnace such as a rotary kiln for manufacturing cement clinker, which cooler comprises a supporting surface for supporting a bed of material, said supporting surface being made up of a number of elongated, parallel conveying lanes which can be moved back and forth in their longitudinal direction, and being jointly moved in the direction of conveyance of the material and individually or in groups in the opposite direction, and an underlying compartment from which cooling air is led up through gaps in the supporting surface for cooling the hot bed of material.

Devices utilizing the above mentioned principle of conveyance are generally known, inter alia under the designation "walking floor". Also known are coolers for cooling hot particulate material utilizing this principle of conveyance. The conveying efficiency in such coolers has proved to be excellent. However, particularly for coolers used for cooling cement clinker the mentioned principle of conveyance has shown to involve a serious problem in that hot clinker material is sticking together and forming even very large lumps of hot material, which will significantly decrease the cooling efficiency of the cooler since the cooling airflow is unable to penetrate and cool these lumps, with the airflow instead being diverted relative to such lumps.

It is the object of the present invention to provide a cooler for cooling hot particulate material by means of which the aforementioned disadvantage is eliminated.

This object is achieved by means of a cooler of the kind mentioned in the introduction and being characterized in that it comprises means for providing local, vertical displacements in the bed of material.

As a result, the cooling efficiency will be significantly improved since the clinker material is prevented from sticking together to form large lumps. This is due to the fact that any early-stage formations of lumps will be stopped in that the bed of

material is locally subjected to vertical displacements, thereby breaking up agglomerated pieces of material.

The means for providing local, vertical displacements in the bed of material, in the following referred to as the displacement means may in principle be made up of any appropriate means which will subject the bed of material to the desired influences. The displacement means may thus be made up of bars or plates extending crosswise to the direction of movement of the material and protruding into the bed of material. The displacement means in the form of bars or plates may either be stationary and attached to the stationary machine frame of the cooler or they may be fixed to the conveying lanes. If the displacement means are stationary, they will provide the desired vertical displacement of the material when the conveying lanes are jointly moved in the direction of transport of the material. If the displacement means are fixed to the conveying lanes, thus following the movement of the latter, they will provide the desired vertical displacement of the material when the conveying lanes are moved individually or in groups in the opposite direction relative to the direction of transport of the material. In the latter case it is preferred that the maximum length of the displacement means is equal to the width of the conveying lanes.

The displacement means project at least 10 mm into the bed of material, preferentially between 10 and 100 mm and most preferentially between 20 and 50 mm.

The invention will now be described in further details with reference to the drawing, being diagrammatical and where

Fig. 1 shows a side view of a cooler according to the invention, and

Fig. 2 shows a sectional view through the cooler shown in Fig. 1.

In Fig. 1 and 2 is shown a cooler 1 which is installed in direct extension of a rotary kiln 2 for manufacturing cement clinker. The cooler comprises an inlet end 3, an outlet end 4, end walls 5, 6, a bottom 9, a ceiling 10, an underlying compartment

11 , a fan 12 for supplying air to the compartment 11 and a supporting surface 13 for receiving and supporting the hot material 24 which is to be cooled. The supporting surface 13 is made up of a number of elongated, parallel conveying lanes 14-19 capable of being moved back and forth in their longitudinal direction, and being moved jointly in the direction of transport of the material, indicated by the arrow 17, and individually or in groups in the opposite direction. The cooling air is led up through gaps, not shown, in the supporting surface 13 for cooling the hot bed of material 24.

According to the invention the cooler comprises means for providing local, vertical displacements in the bed of material 24. In the shown embodiment these displacement means are made up of plates 22 which are fixed to the conveying lanes 14-19, and extending approximately across the entire width of each of these lanes. During the operation of the cooler where the conveying lanes 14-19 are jointly moved in the direction of transport of the material and moved back individually or in groups in the opposite direction, the plates 22 will provide vertical displacements of the material during the retraction of the conveying lanes, thereby causing any agglomerated lumps of material to be disintegrated into smaller pieces.