DK142962B - CALCINATION PLANTS FOR FINE CORN AND POWDERED MATERIALS NAMELY CEMENT MATERIAL - Google Patents

Description

(wt i ΒΒΗΓ (11) PUBLICATION 142962 DENMARK (ευ im.ci.3f nb 15/02 UMIXIVIMniX B 01 J 6/00 // F 27 D 13/00 '(21) Application No 3999/75 (22) Filed on September 8, 1975 (24) Running Day 8 · ρβρ 1975 (44) The application submitted and the petition published on the 2nd mStP.198l

DIRECTORATE OF

PATENT AND TRADEMARKET SYSTEM (30) Priority requested from 10 Sep. 1974, 6194/74, CS (71) PREROVSKE STROJIRNY NARODNI PODNIK, Prerov, CS.

(72) Inventor; Petr Nemecek, Sirava 2759 »Prerov, CS: Jirl Pilous, Party * zanska 32, Prerov, CS; Josef Pleek, Dvcrakova 45, Prerov, CS: Zdenek Zacpal, Hornl Mostenlce 389, TJs.

(74) Plenipotentiary in the proceedings:

Civil Engineering M.Gregersen.

1 ........ 11 "I 1 11 11 '' ..... I 1 1 ....... ί .. II. II. 11) 1.-I. (54) Grinding systems for fine-grained and powdered materials, named * cement cement.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a fine grain and powdered materials calcining plant, in particular cement raw material, powdered lime, alumina, gypsum and similar materials, and the plant forms part of a complete plant for burning said materials.

From German Publication No. 1 934 389 there is known a plant for burning powdered lime, which plant has no rotary kiln, but a vortex separator which is directly and coaxially connected to the lower part of the reactor. This is coupled to a cyclone separator by means of a pipeline into which material from the reactor can be bonded. This known plant is not useful for calcining e.g. cement raw material.

New technological processes are now being used to treat powdered and fine-grained materials in plants, which material is predominantly processed in suspended state. Eg. For example, in the field of cement clinker manufacture, new methods for burning the cement clinker have been introduced, in which a calcination system with separate fuel supply is inserted between the rotary kiln and a dispersion heater. In this calcination system, a predominant part of the calcination takes place, so that in the rotary kiln only a sintering process and possibly an end of the calcination process is performed.

The technological processes that exploit the advantages of a di-10-processed raw material in the flow of hot gases require that the complete plant contain a plant which, at a certain stage, allows the raw material to be separated from the gases. This applies to the calcination system, in which the raw material is decomposed in the gases and where after completion of the calcination it is necessary to ad-15 '. separate the two components. In addition, in practice, separators, called hot cyclones, are used which work in a known manner. The mixture of gases and raw materials flows tangentially in the horizontal direction into the cylindrical space where the mixture is rotating. The small parts of the dust concentrate under the influence of the centrifugal force at the walls of the cylinder, and after dipping, they slide down into the lower part of the cyclone from which they are removed. The purified gases flow from the cyclone through a drain line located at the vertical axis of the cyclone.

The problems and operational difficulties hereby arise as a result of the necessary design coupling of the outlet from the calcination system with the inlet to the hot cyclone. Since the outlet of the calcination system is vertical, while the inlet of the hot cyclone is horizontal, the connecting duct must be formed as an arc with a horizontal part. This horizontal portion is a critical site for forming 30 accumulations of hot dust and larger-sized adhesive parts that fall out of the calcination system. These accumulated parts then cause a narrowing of the profile in the channel and often cause a complete clogging of the lower part of the calcination system due to the hot raw material. Under these conditions, the operation must not only be interrupted, but there is also a risk of explosion because the fuel cannot be burned in the calcination system. The purification of such a design node under the operating conditions found in high capacity units is very difficult and long lasting and places great demands on a worker protection standpoint.

3 142962

The present invention aims to provide a plant by which the said problems are solved and the stated deficiencies are avoided, and this is achieved according to the invention in that the plant is designed as defined in the characterizing part of claim 1.

5 In this design of the system with two spaced spaces, between which there is a channel for the discharge of the waste gases from these spaces, the removed adhesives and abutments from the upper compartment can fall freely into the lower compartment from which they can is discharged without any clogging of the duct to outlet 10 of flue gases or of the duct through which combustion air is supplied.

By designing the calcination plant as claimed in claim 2, the possibility of controlling the extraction of the gases is obtained and thus an improvement in the reduction of the adhesions without clogging the duct.

In designing the calcination plant as claimed in claim 3, the best possible separation of the raw material from the branched channel to the preheater can be further ensured.

The invention is further explained with reference to the drawing, in which FIG. 1 shows a side view of an embodiment of the calcination system; FIG. 2 is a sectional view taken along line A-A of FIG. 1, FIG. 3 is a section along a line B-B in FIG. 1, FIG. 4 shows another embodiment of the calcination system according to the invention; FIG. 5 is a sectional view taken along line A-A of FIG. 4, and FIG. 6 is a sectional view taken along line C-C of FIG. 4th

Corresponding parts in the two embodiments are designated by the same reference numerals.

In the embodiment of FIG. 1 is a reaction chamber formed by a vertical reactor 1 of annular cross section and with an outlet 5 directly and coaxially connected to an inlet 4 of a vortex separator 3 which also has an annular cross section. The separator has a flue gas duct 7 and an exhaust funnel 9 for the heat treated raw material. To the hopper 9 is immediately connected a spill closure 11 and a pipe 13, which serves to direct the separated raw material to a rotary kiln 14. A burner 18 is arranged in the ceiling part of the reactor 1, under which a gas channel is tangentially connected. 15 from a cooler not shown in the drawing. In the lower part of the duct 15, a pipe 16 through which 5 preheated raw material coming from a preheater 20 is enclosed, thus an inlet duct 19 is attached to the duct 7 for discharge of the flue gases. This channel 7 is connected in a direction opposite to the flow of waste gases and of raw material to be processed, which direction is determined by the direction of the inlet of channel 15.

10 The embodiment of FIG. 4, the embodiment of the system differs from the system described above in that a hot cyclone 2 is connected to the outlet 7 for the discharge of flue gases from the reaction chamber with the inlet duct 6, whose outlet nozzle 17 is connected to the inlet duct 19 of the preheater 20.

15 To the discharge hopper 9 from the vortex separator 3 and also to a discharge hopper 8 from the hot cyclone 2, damper valves 10 and 11 and pipes 12 and 13 for the separated feedstock are connected respectively, which last pipe opens in the rotary kiln 14. The mutual position of the tangential ducts 7 and 15 are also another in the embodiment of FIG. 4, the outlet channel 7 for the exhaust gases being connected in the direction of the flow of flue gases and of the treated raw material, and the flow direction is determined by the direction of the inlet of the channel 15. The vortex separator 13 is preferably of the same dimensions as the hot cyclone 2.

The raw material is processed technologically in the reactor 1 due to the direct influence of the fuel on the dispersed raw material particles. Thereafter, a separation in the space of the vortex separator 3 occurs as the basic condition for the separation of powdery particles in a cylindrical space - rotation of the mixture - is maintained, as it is ensured by the tangential supply channel 15 in the upper part of the reactor. 1. In practical tests, it has been proven that the separation ability of the vortex separator in the plant according to the invention for the given technolotic process is satisfactory in view of the extreme temperature conditions.

Due to the different position of the duct discharge channel from the vortex separator 3 with respect to the channel 15 which opens into the reactor 1, the separability of the type of vortex separators in question can be significantly affected. The choice of the said mutual position depends on the fraction composition of the raw material to be processed, the physical properties of the raw material and the

Claims (2)

5 142962 the requirements for the final product. The raised adhesives and attachments are mechanically removed on the inner walls of the reactor 1 and coincide with the treated raw material included by the gases into the vortex separator 3, 5 where they accumulate in the lower part and are removed through the discharge funnel 9, the damper cover 11 and the tube 13 of the rotary kiln 14. In the alternative embodiment of FIG. 4 with a given degree of excretion for the vortex separator 3, the treated raw material is also separated from the flue gases. The separated raw material is then removed from the plant either through the discharge funnel 9 or through the discharge funnel 8 or through these two simultaneously and is fed through the damper closures 10 and 11 and the pipelines 12 and 13 for further treatment in the rotary kiln 14. In the plant according to the invention for calcination of fine-grained and powdered materials, an increased reliability is obtained and the plant forms part of a complete plant for burning the materials. In particular, operational safety is achieved by the fact that it is not possible to block the pathways for exhaust of the flue gases and to supply combustion air to the reaction chamber. In particular, this 20 increases the safety of the combustion process and makes already known combustion appliances with 2-current device of the gas supply completely reliable. A fine-grained and powdery material calcination plant, in particular cement raw material, forming a 25 part of a complete system for burning said materials and consisting mainly of a preheater, a rotary kiln and a cooler, the calcining plant consisting of a reactor (1) and a vortex separator (3), characterized in that the reactor (1) and the vortex separator (3) are arranged directly and coaxially over each other, so that an outlet from the reactor (1) simultaneously forms an axial inlet (4) for the vortex separator. (3) wherein a horizontal duct (7) for extracting gases is branched from the space in the vortex separator (3), which channel is tangentially connected to the vortex separator.