DE2247101A1 - PROCEDURE FOR AFTER-TREATMENT OF HOT BRIQUETTES OR THE LIKE - Google Patents

Description

METAL-LGESELISCHAFT · Frankfurt / lJain, 8.9.197 ?.

Aktiengesellschaft -ΐ / gn / HSz-

No. 7045 LU ο ο / τ 1 η

Z Z 4/1 U I

Process for the aftertreatment of hot briquettes orter like.

The invention relates to a method of machining Hot briquettes or similar shaped bodies with a content of baking charcoal, .the at a temperature between about 350 ° up to 550 ° C are produced.

Hot briquettes are preferably prepared by compression of caking coal ¹ with the addition of non-softening solids, in particular of fine-grained coke, at temperatures in the plastic range of the coal. The coke is heated to such an extent that the mixture of coke and predried and optionally also preheated charcoal assumes a mixed temperature in the range from 400 to 550 ° C. at which it is fed to the briquette press. The ratio of coke to baked coal varies widely depending on the type and type of baker's liking of the coal used and, above all, on the porosity and strength of the hot coke. Ratios of 60 "to 75% by weight of coke to 40 to 25% by weight of baking charcoal are usual.

The object of the invention is to produce briquettes of the type produced in this way with optimum pressure and abrasion resistance ideal for transporting and manipulating in front of the blast furnace as well as for use in blast furnaces as a reducing agent are suitable. According to the invention this is achieved by

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that the hot briquettes move through a shaft through which oxygen-containing gases are passed in counter flow. These gases, to which air is mixed in particular, burn partly carbon on the surface of the briquettes and partly the freevrardendon gases and tar bowls from the briquettes when they are heated. To order the briquettes a. B. 100 ° C zxx , the combustion of about 1.2 % of the carbon of the hot briquettes or an equivalent amount of components is required. The combustion on the surface of the hot briquettes can be suppressed to a large extent by the addition of flammable gases, unless this is already affected by the volatile constituents released.

The combustion in the shaft is controlled so that the hot briquettes by a certain temperature between 50 and 200 'C preferably, are heated to 100 C ₁ via the briquetting. As a result, their content of residual tar is practically eliminated and their content of volatile constituents drops to approx. 5 ¹ A or even below. The briquettes assembled in this way now have the desired pressure and abrasion resistance.

An essential feature of the invention is that circulating gases passed through the shaft ■ metered Amount of air is added. This air burns in the flowing through the briquette and heating up Circulation gases as soon as the ignition temperature is reached and the The combustion temperature is sufficient, and the circulation gases and thus the hot briquettes are heated up cause. The air is the cycle gases in such a Kenge admitted that the burning of the Hei3 briquettes or the combustible components of the cycle gases are just setting the desired temperature. It is convenient that Air gas the circuit before entering the briquette chain admixer. Another possibility is ordering in

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the air through distribution organs in the upper half of the Add bulk briquette where the temperature of the cycle gases and the briquette is higher

An example of the method according to the invention is shown here explained in the drawing:

The hot mix, consisting of a mixture of coke and baking hard coal, is pressed in a double roller press 1 to form hot briquettes. The temperature of the mix is in the range from 400 to 550 ° C and is preferably 450 ° to 480 ° e. On the briquette press 1, the briquettes (not shown in the drawing) arrive via a horizontal conveyor 2 and a steep conveyor 3 to an inlet chute 4, from which they flow to a shaft 5. The chute 4 is expediently equipped with a grate or sieve 6 in order to remove briquette debris and any undersized particles.

The briquettes migrate through the shaft under the effect of gravity in a closed bed, continuously from top to bottom. The lock member 8 of the shaft is controlled so that the shaft is always fully rait up to the distribution chutes 7 Briquettes is filled.

In the shaft 5 at its lower end through the line 9 circulated gases of low temperature are introduced, which are also referred to below as cycle gases. The circulation gases usually consist of the costs incurred by the addition of air and combustion, more oxygen-containing exhaust gases, which Yasserdampf may be added from the direct YJasseriühlung the cycle gas or the final cooling of Beißbriketts "The circulation gases at temperatures swiBchen 30 and 200 ° C before ihrsis entry in the duct 5 air in a dosed amount via the suction line,

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_; BATH

Ira shaft 5 the circulating gas-air-genic flows from the bottom up through the pouring of the hot glasses: e * ts »which are thereby cooled in the lower shaft area! 3a, while the cooling medium warms up. In the upper area 5b of the shaft, the 7-ond temperature is finally reached, and the air in the circulating gases burns partly carbon on the surface of the hot briquettes and partly the gases and tar vapors released from the briquettes during heating.

The air is added to the circulating gases in such a way that the desired temperature is just reached through the combustion of the briquettes. At a drainage temperature of z. B. 450 ° C the Hsiß "bri"!: Etts can cool down to, for example, 420 ° C until it enters the shaft 5. They are then heated to around 500 ° C in the shaft by partial combustion in the bed. The temperature can also be increased to 550 to 600 ° C or even higher if an appropriate amount of combustion air is added. It is important to set the heating temperature so that the content of residual tar in the hot briquettes practically disappears and the content of volatile components drops to below 5%.

With the relatively low 0 «content of the cycle gases and the low combustion temperatures, the combustion takes place slowly and in an extensive zone of the briquette bed. The cycle gases leaving the shaft 5 at the upper end regularly still retain a certain V \ ®np; Q of unused oxygen. The cooling, the combustion and the heating of the briquettes can be monitored by a number of thermocouples (shown) which are distributed in the shaft 5 over the height of the briquette. The temperature of the briquette emitted is also good !; There is no run-of-the-mill gas for heating up the hot briquettes,

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BATH

The dwell times of the hot briquettes sinking downward in the shaft 5 in the heating zone 5b are generally 10 to 20 minutes compared to a delay in the ΣΜΙύΙάζλ = 5 s of about 20 to 40 minutes. In the case of a high heating temperature in zone 5b, a short period of rest is sufficient.

The success of the Mas snahraen is benefiting from the Pesti3aiß.u :: g the content of residual tar and volatile components of the treated hot briquettes is checked. Through-the accordingly dosed amount of air, the appropriate combustion and daiv.it the desired heating of the hot briquettes can be set in the upper part of the briquette bed.

The one at the top of the shaft 5 from the Srikettschüttung Exiting cycle gases are via line 11 in ein.sn Zyklon 12 given and there carried away by the one from the briquette bed Dust cleaned and then cooled in a cooler to a temperature between 30 and 200 ° C. The Kuhlsr can be used as a waste heat boiler to generate steam, as a j5insprii: z ~ cooler with Wasserver attenuation or as indirect air or Be designed water cooler. It is from Yortoil to use it as a steam generator and, in a second stage, as a direct water cooler in In connection with fine recooling of the water in an air or water cooler. The chilled Jirislaufgaso zTasafiten with the zuge.mischten air are by a fan 14 in the. Shaft 5 returned. An excess of cycle gases will derived at 16.

The HeiS briquettes leaving the shaft 5 at its discharge end 15 can be quickly after-cooled in order to avoid possible self-inflammation. To do this, there are various! B. from an aftertreatment with water, e.g. B, by spraying with water or by using τοη immersion pools, can range up to the sole air cooling.

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BAD OBIQiNAL

. Seduction described deviating from Kuvor ", if in the L-;. Via line 10 to the circulation gases before he ei · ^1, '..intriit j η di ■ Rrikettschüttung of .Schacht π zugenischt 5 v / ill, chi can. '.: · JV -. ;;'; also through divider organs in the upper half of the cattle ·: ·:;.; ■ V added four den. The divider organs consist of v ,. 3. au: -:; .. · .-., .-) ■ Large number of parallel, horizontal pipes ? .V: ei it evenly distributed .Ausla Vöf: Oiun;: on for the Lu.fi :. The air is fed to the pipes 20 via a feed line? 2 iv-y /: - leads. The distribution pipes can lie under downwardly open; - ^ roofs 21, v / elche zxxui stiffener) of the pipes? O and in particular equilateral to the front '.- i. ^ cJien of the air with the Jlroi , · -; - serve rungaoeu, wosu the X! Ei'C; ic] i ¹ Ut: Ler den D'iciiei'n au ^ rvfi the 3rili: ettnchüttung suitable int. Kit help this Vert · .-. · :! J rrorgane a slightly different temperature profile can be set over the shaft height than this can be set by the air supply hr ¹ is equal to nc via line 10. The air supply via divider pipes 20 can also be combined with the admixing of air through line 10.

If the fiber line contained 11 emerging from the BrikettscifJttung Kreislaiifga.se yet unburned or ur.T4or.setäte Teerdänpfe, the i-heavy deposits: n Zv "" - ion

or 'iiri cooler give cause, so v; ird zv / ecla-aziger the) circle <\ .-'r.x'-'

Before or after the Zyjclon an oostinu-ite Conga air z \ '.- ge: nisch \ :, ui'ji these tar jars and possibly pre-band he ic pern.anent gases to burn. Should this burn ::: r. '/: R ·. temperatures that are too low are not intense enough, so v.'ird zv / eclaiiä3iger,: eise not air alone, but become hot "" -:.?

Fire gases with excess air 2UgGMi see, ur: the Kreislau: _'::; ^;: se

to be heated sufficiently.

The λ ⁷ experience can not only be used for wear brihets that have risen at a temperature of AOO to 55O ^C C. ¹ ,: ':;: "of fine-grained coke and baked fine coal he are made ;, also for Kei.'ibrJkettr.;, Hor -"; esf ollf Cure) -'! '. ::: - pressing a coal "b ^ .v. a con ^ ication that leads to <: ■!: ■ ο

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BAD O) = IJG (NAL

preferred temperature between 350 and h ^l jQ . C gets ir.t. without giving out hot coconut. The process can also be used for the aftertreatment of hot pellets, which are made in a Drelitroiäiael from a mixture of hot, fine-grained · ;! Coke with pre-dried hz \ r. vorerhitater backe ^ r Feinlcohle are made with and without the addition of Teornech.

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BATH ORIGINAL

Claims (6)

Claims 1) Process for the aftertreatment of hot briquettes or similar shaped bodies with a content of baking charcoal, which are "produced at a temperature between about 350 and 550 ° C" characterized in that the hot briquettes move through a shaft through which oxygen-containing gases flow in countercurrent be directed. 2) Method according to claim 1, ch dadur gekennzelo h ne 1 ₁ that a metered amount of air is added through the shaft directed circuit gases. 3) Method according to claim 2, as through. / y indicate ζ eichnc t, that the air is mixed before entering the gases into the circulation Brikettschüttung. 4) Method according to claim 2, characterized in that the air is mixed in via distribution elements which are arranged in the upper half of the briquette bed. 5) Method according to one of claims 1 to 4, characterized in that that air is supplied in such an amount that the hot briquettes around a certain temperature between 50 and 200 ° C, preferably around 100 ° C, above the briquetting temperature through combustion of combustible components in the circulatory leashes and through partial combustion of the hot broth: etts are heated on their surface. 6) Method according to claim 1 or one of the following, dacl u r c h characterized in that air is added to the cycle gases after exiting the shaft and / or after dedusting in the cyclone downstream of the shaft, ura the tar pods carried along by the cycle gases largely burn or decompose. A098U / 0193