DE2019078A1 - Process for increasing the throughput of coke ovens - Google Patents

Description

20.4.197ο Pr / Pl.

Process for increasing the throughput of coke ovens

Coke ovens with a high throughput capacity need to be completely digested of the coke at heating draft temperatures of 1200-1400 ° C 16-2o hours. A further increase in the throughput of the coke ovens is very desirable, but is rejected in many places because "this increase according to the current state of the art can only be achieved by a Increasing the heating draft temperature is to be achieved. An increase in the heating draft temperature to z. B. over 14oo ° ö, however, requires one considerable complication of the operation due to the higher radiation. Since the well-known masonry made of fireclay and silica bricks can only withstand this stress for a short period of time, a shorter service life of the furnace can also be expected. That means that the increase in throughput achieved in this way would only be paid for with increased furnace wear.

The invention is based on the consideration that an increase in the throughput of coke ovens achieved without any other disadvantages can only be achieved if instead of the previously common stone materials such as fireclay and silica stones, which have a V / thermal conductivity at 1200 ° C of about 1 - 1.5 kcal / m hour χ ⁰ C, the furnace bricks, in particular the so-called runner and binder bricks of the heating flues, consist of refractory bricks that have a much higher thermal conductivity.

109846/0660

2019Q78

The "known in Koksofenbau refractory bricks are the silica bricks which to 9o <fi consist of SiO _2, and the Schamotteund sillimanite bricks that essentially of from about 4o -. 65 / = from AIPO, 'and the rest of SiO. _? and consist in all cases of oxides of trace elements, such as ITe ₂ O ,, MgO and CaO. In addition, silicon carbide stones are known that consist of silicon carbide to 5o ^c /> and above. The thermal conductivity of a 9o ^ igen SiC stone is 13-15 kcal / mhC. It has been shown, however, that the known SiC bricks, which in addition to SiO essentially _{contain Al 2} O and SiO ₂ , are unusable in coke ovens because they are sensitive to oxygen that in the coke oven there is a regression of the SiO to SiO ₂ and C and thus the masonry soon disintegrates.

It has now surprisingly been found that the throughput of coke ovens can be increased significantly by carrying out the coking of the coal in ovens in which the brickwork forming the coking chamber and heating flues and possibly also the substructure consists of stones that are only about 1o - Contains 45 i ° SiO.

Refractory bricks, i.e. silica bricks, fireclay bricks and sillimanite bricks are - provided they also contain about 1o - 45 ^o ß> SiC - in coke oven operation in contrast to SiC bricks with a SiC content of 50 $ and above, form and dimensionally stable and have a better mechanical strength than silica and fireclay bricks without SiC content, so that thicknesses of around 50 - 65 mm are sufficient for the runner bricks of the heating flues. If this is statically justifiable, they can even be designed to be even weaker, for example a thickness of 40 mm, but instead also stronger and for example a thickness of 80 mm. For reasons of thermal expansion, it can also be useful that the masonry of the substructure of the furnace chambers is also made from the stones according to the invention.

109846/0660 BAD ORiGiHAL

_ 3 -

In-depth investigations have shown that an increase in the thermal conductivity of the lining of coke ovens over a value of about 6.5 kcal / rah ° C for the coke fermentation process, in particular is detrimental to the quality of the coke. This is due to the fact that the thermal conductivity of the coking coal and the coking products is not large enough to absorb any amount of heat quickly enough. The heat offered by the stove bricks must rather be adapted to the heat absorption capacity of the furnace filling be. According to the invention, the thermal conductivity of the lining, In particular, the runner stones have a value of about 2.5 - 6.5, preferably 3-4.5 kcal / mh C.

As refractory bricks, which are particularly suitable for carrying out the inventive process, so come rotor and tie stones in question to 4o - made $ 65> of Al ₂ O ,, in the rest of SIOP and oxides of trace elements and additional 1o - 45 i ° i preferably contain 2o - 4o fo silicon carbide. In technical tests it has already been confirmed that this stone material can withstand the stresses occurring in coke ovens, in particular the effects of oxygen, but also of solid carbon, steam and gaseous hydrocarbons, both on the heating draw side and on the chamber side.

The following table shows the previous data for assessing the value of a 40% SiC brick, in particular for coke oven operation.

109846/0660

2019Q78

Refractory brick with 4o Iq SiO

1 °. 0.08

, * 24.5

Fe ₂ O ₃ , io _{0} 3}

Al ₂ O ₃ , ic _{36 $ 4}

SiC, io _33jO

Pressure fire resistance approx. 182o

Thermal conductivity

at 500 ° C, kcal / rah ° C 4.5

¹¹ 1ooo " ^f ""4.2

»» 4, o

V / arm extension

at 500 ⁰ C, io o, 2

"I000" o, 5

¹¹ Hoo "o, 65

Volume weight, g / cm 2.5

Porosity, <f » 9 -

Cold compressive strength, kg / cm 400-5oo

The attached drawing shows a plan view of a horizontal one Section through 2 heating trains of different designs. The numbers 1 in Figs. I and II denote the so-called runner stones, which at the same time each form a wall for the right and left adjoining coke oven chamber. Number 2 - denotes the tie, which provide support for the heating draft walls. The shapes of the stones according to Fig. I and II are, as you can see, different. Such different shapes are known and are not the immediate subject of the invention. As you can see, they are Stones held together by tongue and groove. The joints between the stones are filled with refractory binders.

example

A furnace chamber with a chamber width of 450 mm was lined with refractory bricks with an addition of 40% silicon carbide from the table above with a wall thickness of 58 mm. In this chamber a coking coal 24.8 fo volatile matter (9 fo water content) was coked at a Heizzugtemperatur of 1300 ⁰ C. The coke had already been cooked after 7 hours. The pressed and quenched coke still contained 0.06 % volatile matter.

109846/0660

Claims (1)

P a t e η t a η s? S r- ü ehe 7®rfehren to increase the Burelnsafczleisfeung τοίι coke ovens ^ Gaöi'ir-oh. That the coking of coals takes place in ovens in which the the Kolarngsicssimer and Helssug form the masonry and possibly also a foundation made of fire fuses «Stones consist ^ which contain additional ile-li 10-45 $ Siliciumeaiijid _o 2ο ¥ @ A "" Aahren nach Än _t sprucli I ₅ dacMr-eli gekennz3icl5iist. _g that the 'stones have a thermal conductivity of efctja 2 ^ 5 - örS KGaIAiI ₀ IIo ⁰ Ci > »Coke ovens according to implement the method in claim 1 - 2 characterized in _S that -the Yerkoirangslcanimer and flues forming Mauenverk and possibly also CLSI _o" Unfcs.Pbau of refractory bricks consist ^ © oil gusätslißä 10 ■ = 45% _s preferably. 20 - 40 % silicon carbM er / ciialr.sn = 4ο Refractory bricks _s especially IMMfer wan bindings for the coke oven constructionj, which are 40-65 $ from AI ^ -Gw, Ibi remaining from st J d and Cteydejs characterized by, trace elements besteiiea ^ daduroii ₅ that these stones additionally contain 10 - ^ll 3 f's - preferably 20 - 40 % ψ silicon carbide ^ 5 »Refractory stones, especially runners and binders for Kbksofenbau ₅ the su order over 90% from SiOp and ira the rest of oxides of trace elements, dadwrcii .. that these stones additionally 10 = 45 % _ΰ ^ o -Fssagewise 20 ■ = KO% SiIi ciumcarfoid contain ₀ 1 0 S i 4 S cf 0 (31 @