DE1796018A1 - Method and device for the production of cement clinker - Google Patents

Description

PATENT LAWYERS DR. IN6. A. VAN DER WERTH DR. FRANZ LEDERER ^ * '"

21 HAMBURS 9O 8 MONKS 8

WILSTORFER STR. 32 -TEL. (O4T0 T7O861 LUCILE-GRAHNSTR. 22 ■ TEL. (O8 11) 44O846

6144-3

YOUR MESSAGE FROM: MY CHARACTERS: HAMBURS-HARBURQ.DEN

NS,

F.l.Smidth & Co. A / S.

Vigerslev Alle 77, Copenhagen-Valby / Denmark

Method and device for the production of cement clinker.

Priority: British patent application

39 495/67 of August 29, 1967

Many of the rotary kilns used so far, "for example in the cement industry, are designed so that the they exiting exhaust are pretty hot. Their temperature is around 650 G and more and that in these gases contained heat is then in some apparatus before the

O furnace used up. These apparatuses are of various kinds

β> Kind of, most of which are used to draw the heat up from the gases transferring the material fed into the furnace,

o> so that it is preheated. An often used appa-

cn rat is a multi-stage cyclone preheater in which the gases go through the successive cyclones and

DEUTSCHE BANK **., HARBURa U3 / 2O »13 POtTtCHICK: HAMBUH6 1173 3O TELECONiaCHK AGREEMENT REQUIRES WRITTEN MBSTATICUNe BAD ORlUiNAL

the raw material from which the gases last flowed through Cyclone is introduced into the dough pipe leading to the previous cyclone, etc.

Another form of apparatus in which the heat in the gases is used is a grinder, 2.B. a crusher or a mill in which the moist raw material is broken or ground up and during this doorway is dried by the heat in the gases

The gases are usually drawn from the rotary kiln and through the apparatus, wherein the ^w änae is exploited by a fan · This fan has not only the necessary ^ ug by the actual oven, but also the required train to the gases through the preheater, To pull the crusher or mill, produce, and that is why it has to be big. In addition, because false air enters the preheater and the pipe connections _T and has to pass through the blower, its dimensions must be increased accordingly. In addition, fluctuations in the pressure drop caused by gate heaters or shredders, for example due to clogging or irregular feeding, impair the draft through the rotary kiln and make it difficult to regulate its operation.

These deficiencies could to a large extent be eliminated if the fan were located near the furnace, however the temperature of the gases when they are exposed to the oven, is so high that it would damage a standard exhaust fan.

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According to the invention, the gases are from the rotary kiln nacijenander through a shaft »a cyclone and a Blower is passed through and moist material is fed into the shaft. Some of this material will carried by the gases to the cyclone and enters it in a substantially dry state, Der The rest of the material falls under the influence of gravity in countercurrent to the hot gases past the point of introduction of the gases into the shaft. the Amount of moist hollow material, which is in the shaft is such that the gases are cooled sufficiently to come into contact with the fan naen to be able to go through the cyclone. The shaft serves as a rapid dryer, and Material suspended in and carried away by the gases is separated in the cyclone - a limited amount wrong air can penetrate the pipe, which leads from the rotary kiln outlet to the suction side of the fan and includes shaft and cyclone, but this will not significantly affect the required size of the fan.

Of course it is necessary to prevent the hot gases Mre ¥ »TUneirg» from leaving the shaft at the point where the moist material enters it, or that it comes out of the shaft with the partially dried material step out. The invention therefore also includes as one new plant - a combination of a rotary kiln and a shaft receiving the furnace gases and leading to a cyclone, from the gas outlet of the cyclone

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a conduit leads to a blower, and an inlet with a DrehfiSsiüP or other seal for the introduction of moist material into the manhole and a rotary valve or other seal for regulating the passage of the partially dried material from the bottom of the shaft.

The hot gases heat away entzpgene ater ^w of the wet material and is thus effectively exploited ·

The invention can be applied in processes using various materials in the rotary kiln »e.g. cement raw material, Limestone, or ore, to be burned. That Moist material fed to the shaft can be the raw material subsequently fired in the rotary kiln or a component be of this, or it can be after its

to
The purpose was to cool the exhaust gases / while it was partially dried itself, to be used somewhere. However, the invention is of particular value for use in a process wherein cement raw material is burned into clinker and wherein the moist material supplied to the shaft is one of the constituents, e.g. limestone, of the raw material.

Limestone, if so used as a moist material, and Most of the other materials that can be used and partially dried in this way also normally have to be grind and be completely dry · Approved Thermal economy is obtained by another feature of the invention, being crushing or grinding

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of the partially dried material and its simultaneous Drying takes place by means of the gas given off by the fan and subsequent separation from this gas.

The preferred plant according to the invention therefore closes 'one arranged in this way in combination with the rotary kiln Crusher; or a mill to collect the partially dried material, one from the pressure side of the fan

r 1

line leading to the bucket or trouble and one Separator, which is connected to the crusher or mill via a line, to remove the broken or take up ground material in the gas stream,

Two systems according to the invention are described below schematically and, for example, explained in the drawings

In the Pig · 1 plant, moist material is discharged into a funnel 1, from which it is under control

lock

through a rotating shaft 2 through a pipe 3 into a vertical one Riser pipe 4 of a cyclone 5 goes. The riser pipe 4 is mounted on a gas chamber 7, which with the End of a rotary furnace 6 is connected so that the hot gases from the furnace into the chamber 7 in the usual way enter. Raw material to be burned is put into the rotary kiln fed through a triohter 8 and a line 9 under control by a valve 10 and goes through as usual the chamber 7 »as shown in dashed lines in the drawing ·

The gas chamber 7 is in contrast to conventional exhaust gas chambers open at the bottom, where it merges into a funnel 11.

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The chamber 7 and the riser 4 * which are directly placed thereon, together form a shaft in which most of the moist material from the funnel 1 under the effect of gravity through the gases from the furnace

falls through it and at the mouth of the oven / into the funnel 11 · Some fine particles of the wet material are inevitably carried up through the riser 4 into the cyclone 5 where most of the hot gases is deposited.

The outlet of funnel 11 is on via line 12 a conveyor 13 is connected and the outlet of cyclone 5 is regulated via a line I4f by an I> re valve 15 »connected to a conveyor 16 ·

The gases are passed through the cyclone 5 and a drill 7 a fan 18 sucked. Bohr 17 contains a throttle valve 19, the setting of which regulates the train la furnace can. This train can also be done by changing the speed of the fan 18 or, of course, by both, namely Changing this speed and adjusting flap 19 can be regulated

From the fan 18, the gases go through an Eohr 20 out an electrostatic precipitator 21 for final cleaning before they are discharged through a pipe 22.

The dust separated in the electrostatic precipitator is collected in a bottom funnel 23 and passed through a Conveyor 24 removed.

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The ^ö tröme of limestone and & deaf are brought by the conveyor 13, 16 and 24 to a line 25 and combined therein, from which the mixture further treatment can be zugefiinrt.

The plant shown in Fig. 2 is particularly designed for drying and crushing limestone, which can have a water content of 20-25 # and a '- ^ eil of cement raw material which is fed into the rotary kiln to be burned into clinker. In this system the outlet of funnel 11 is through a crushing valve 26 regulated in a line 27, which leads to a crusher 28, wherein the partially dried Materials are crushed. At the same time it is further dried by gases from the cyclone 5 »which withdrawn from the cyclone through line 17 by means of blower 18 and discharged in line 27 to by Crusher 28 to go through. The valve 26 effectively prevents the gases from going up in the chamber. By adjusting the speed of rotation of valve 26, material can be accumulated in hopper 11 so as to improve the seal.

The partial drying of the Kalksteinfy which takes place in the shaft and in particular in the riser tube 4, makes the limestone suitable for crushing in the crusher 28. The temperature of the - ^ eehofen 6 gases leaving may be about 65O ⁰ C and AFCS result of the removal of products from these The gases falling through the limestone

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Temperature do at least 150 ° C. in the shaft and cyclone 5, so that the temperature of the gases in line 17 is around 400 to 500 ^° C. The fan 18 can withstand gases of this temperature and can therefore be installed immediately behind the cyclone 5 as shown.

The gases, after they have further cooled by about 150 ö as they pass through the crusher 28, enter a line 29, through which the ground limestone in suspension in the gases on a Zyklon 30 is worn. Here there is such a separation of pesticides from the gases that this can now go on via Hohr 31 to an electrostatic separator 32 for final cleaning ^ before being released through pipe 33 either directly to the atmosphere or to a chimney To reduce the load on the blower 18, it is advisable to have a second blower 34 in the tube 31 to be provided.

The solids separated in cyclones 5 and 30 are Via bottom pipes 14 and 35 »regulated by valves 15 and 36, emptied into a cutting conveyor 37. Of the The dust deposited in the separator 32 falls behind at the bottom through a bottom funnel 38 into another screw conveyor 39 »Both conveyors are emptied into a funnel 40 and from this flows the combined stream of solids and dust via line 41 to further treatment.

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In the method according to the invention, this further treatment comprises mixing with other ingredients and finally grinding in a fine grinder to get the ground To make material suitable as coal flour for the production of cement clinker. Naturally, the equipment wherein this further treatment takes place, are so included in the whole tray that the generated Raw meal is fed in a steady manner into the hopper 8 and thus into the oven 6.

In the fine grinding mill, the oohmehl can be used further be dried, and in this case some of the gases leaving the cyclone 5 can be diverted to this mill will.

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Claims (5)

-10 claims 1. Process for burning cement raw material, limestone, ore or the like in a rotary kiln, characterized in that the gases from the ° fen then through a shaft, a Cyclone and a fan are passed, from which part of it with the gases to the cyclone in one is entrained in a substantially dry state and part of it under the influence of gravity in countercurrent to the hot gases at the inlet put the gases in the shaft falling by and partially drying, making the gases sufficient cooled so that they can come into contact with the fan after passing through the cyclone. 2a method according to claim 1, characterized in that the partially dried material broken or wedded and at the same time through by The gas given off by the fan is further dried and then excreted from this gas. 3. Method according to claim 2, characterized in that g e k e η η draw; that the material fired in the furnace is cement raw meal and that supplied to the shaft Moist material is limestone, which after breaking or grinding is part of the raw cement forms. 109818/0685 4. Plant for use in one of the methods of the preceding claims, characterized in that that it comprises a combination of a rotary kiln, a viewing shaft for receiving and guiding the furnace gases to a cyclone, from whose gas outlet a line leads to a fan, a shaft outlet with a B. .lock Drehroaück or another lock for the introduction of the moist material in the shaft, and a Drelive valve or other closure to regulate the Passage of the partially dried material from the bottom of the shaft. 5. Plant according to claim 4, characterized in that the shaft is formed by a gas chamber which is connected to the furnace end and is open at the bottom, and a riser pipe arranged on the chamber. 6. Plant according to claim 4 or 5, characterized in that it also comprises a crusher or a mill for receiving the partially dried material, one from the outlet side of the fan to the Crusher or mill leading line and a separator, which through a line to the crusher or Mill is connected to take up the broken or ground material into the gas stream. 109818 / Π685 BADOFHGtNAL