DE2019078C3 - Refractory brick containing SiC for the lining of discontinuously operated coking ovens - Google Patents

Description

The invention is based on the consideration that a disadvantage.

Increase achieved without other disadvantages The invention is based on the object for

the throughput of coking ovens can only be achieved 45 discontinuously operated coking ovens can graze if, instead of the usual increase in throughput, a selection of stone materials such as fireclay and silica bricks, certain SiC-containing refractory bricks with a thermal conductivity at 1200 ⁰ C of around which have a thermal conductivity of 2.5 to 6.5 kcal / mh ° C, 1 to 1.5 kcal / mh ° C, for the lining of preferably 3 to 4 kcal / mh ° C,
discontinuously operated coking ovens SiC-50 This object is achieved according to the invention in that refractory bricks containing increased thermal conductivity are used in that the bricks, in particular the runners, are used. Binder blocks, in addition to SiO ₂ , 10 to 45 weight

The refractory bricks known in coke oven construction percent, preferably 20 to 40 percent by weight SiC, are the silica bricks, which consist of over 90% SiO ₂ or 40 to 65 percent by weight Al ₂ O ₃ , and the fireclay and sillimanite bricks, 55 to 35 60 percent by weight SiO ₂ plus 10 to which essentially contain about 40 to 65% of Al ₂ O ₃ 45 percent by weight, preferably 20 to 40 percent by weight and the rest of 35 to 60% SiO ₂ and all percent SiC.

Cases made of oxides of trace elements, such as refractory stones, i.e. silica stones, fireclay special Fe ₂ O ₃ , MgO and CaO. From the stones and sillimanite stones - provided they also contain about 10 to 45% SiC in the magazine "Technische Mitteilungen" 59 (1966), 60 - in the coke oven operation p. 452 and 453, it is known that the through- in contrast to SiC -Stones with a SiC content rate performance of a coking furnace in addition to the chamber of 50% and above, shape and size and width and the heating draft temperature also have a better mechanical strength than the thermal conductivity of the stone material is dependent on. Silica and fireclay bricks without SiC content, so one has only learned from this knowledge that for the runner bricks of the heating flues strengths, the density (porosity) of about 50 to 65 mm is sufficient. You can even - if the main silica stones used are made of copper - this is statically justifiable - should increase the amount of iron or titanium oxide added to a lesser extent. be formed, for example a thickness of 40 mm,

but instead also stronger and, for example, a M) I have a height of 80 mm. For reasons of heat

For the rest, it may be useful to know that also the masonry of the substructure of the furnace chambers aLis the stones according to the invention is created

Extensive investigations have shown that an increase in the thermal conductivity of the brick lining of coking ovens over a value of about 6.5 kcal / mh ^{above sea level} is detrimental to the coke arune flow, in particular to the quality of the coke. This can be attributed to the fact that the thermal conductivity of the coking coal and the coking products are not great enough to absorb any large amount of heat quickly enough the brick lining, especially the runner pieces, have a value of about 2.5 to 6.5 kcal / mh ° C from 3 to 4 kcal / mh ° C

As refractory bricks, the management particularly for the transit '' of the lining according to the invention are suitable, so the rotor and binder stones are suitable,

^{Zl40 to 65} ° / ° ^{from A |} 2 ° 3. otherwise from 35 to d Od

Fire fighting

^ gO% J, te

Al ₂ O ₃ ,% ^

Pressurized fire around 1820

Thermal conductivity

^bel 000; C, kca -mh C 4.2

^bel 1400 ⁰ C, kcal.'mh C 4.0

Thermal expansion

^at , j®? ^> J

^{at IOOÜ C} '■' · '' L

at 1400 ^° C.% 0.65

Volume weight, g / cm ^J 2.3

PoroMtät, ° / o ^{9 bls]!}

Cold compressive strength, kg / cm * 400 to 500

The drawing shows a plan view of a horizontal section through two different heating flues

o / Q · / ° ^| 2 ° 3. otherwise from 35 bis type. The numbers 1 denote in the F i g. I.

J ₀ SiO ₂ and oxides of trace elements consist of 25 and II the so-called running stones, which at the same time and additionally contain 10 to 45 ° / ₀ , preferably 20 to 40% each of a wall "for the silicon carbide adjoining on the right and left. Form coke oven chambers in technical experiments Number 2 indicates that it has already been confirmed that this stone binder, which supports the heating draft walls material both on the heating draft side and on the chamber side. The shapes of the stones according to FIG Such a discontinuous operation, in particular also different forms, are known and not the effects of oxygen, but are also directly subject of the invention.As one sees solid carbon, steam and gaseous carbon, the stones are hydrogenated by tongue and groove withstands .. held .. The joints between the stones are with

The advantages achievable with the invention consist of 35 refractory binders filled,
in particular that the cooking times of the coke
in the discontinuous operation of the coking ovens
can be shortened considerably. This works without the
Raise heating flue temperatures because the over the
Hiü d

example

A furnace chamber with a chamber width of

gp öhen because the over 450 mm was made with refractory bricks with an addition

Heating cables to the runner stones and over them the 40% of 40% silicon carbide in the table above The amount of heat supplied to the load is fully lined with a wall thickness of 58 mm, is used The achieved Stei d Dh In this chamber, a coking coal with 24.8%

volatiles (9% water content) _{ner e} j Heizzugtemperatur of 1300 ⁰ C coked. Already

The amount of heat carried is fully utilized. The achieved increase in throughput the coking furnace is therefore large with the same amount of heat.

D hf

gg _e j _ner Heizzugtemperatur of 1300C carbonized. Already

The following table shows the previous data 45 after 7 hours the coke had finished cooking.

for assessing the value of a 40% SiC closed. The pressed and extinguished coke contained

Stone, especially for the coke oven operation. still 0.06% volatile components.

1 sheet of drawings

Claims (2)

20i9078 J 1 2 In addition, the Didier-Taschen patent claims: calendar 1967, p. 29, Siliciumearbidsteine are known that according to their intended use with a 1. SiC-containing refractory brick with a content between 40 and 90% silicon carbide in the thermal conductivity of 2.5 to 6.5 kcal / mh ^{above sea level} , 5 trade. However, these stones may not be used at a rate of preferably 3 to 4 kcal / me C. for the lining of oxidizing furnace atmospheres. The thermal conductivity of a 90% SiC brick, which is operated discontinuously, is in the form of runner and binder stones, for example at 13 to! 5 kcal / mh ° C. Also from the line characterized by the fact that the writing "Gießereipraxis", 1958, p. 478, it is known, stones in addition to s "iO, additionally 10 to 45 weight percent that the group of carbon-containing production percent, preferably 20 to 40 percent by weight Silicon carbide bricks counting the highest: SiC, or in addition to 40 to 65 percent by weight AUO ₃ thermal conductivity of all refractory building materials and 35 to 60 percent by weight SiO, also sit, these bricks, however, in the foundry and smelter -10 to 45 percent by weight, preferably 20 to industry do not play a role, since they contain 40 percent by weight SiC. 15 oxygen-rich furnace gases oxidize the stones and 2. SiC-containing refractory brick would be destroyed according to inflation with expansion. Also in the claim 1, characterized in that the rotor heating cables of the coking ovens, however, prevails one stones are 50 to 65 mm thick. oxidizing atmosphere. It has therefore been shown that the known silicon carbide bricks, which in addition to 20 50 to 90% SiC essentially Al ₂ O ₃ and SiO_, contained, are unusable in coking ovens, since. they are sensitive to oxygen, so it is im Coking furnace to a regression of the SiC / <: SiO ₂ and C and thus the Mauei 25 plant will soon decay. A coking furnace with a high throughput capacity is required from German patent 332 382. term for the coke to burn out at Heizzugtempera- finally known that the lining of Verturen from 1200 to 1400 ⁰ C 16 to 20 hours. A coking furnace, which should be operated continuously, should consist of further increasing the throughput of the coking SiC-containing refractory bricks. Stoves are very desirable, but in many places, stones are supposed to serve as masonry, which leans against a high, because this increase has heat storage capacity according to the current state of the art. Furthermore, in each of the technology it should only be achieved by increasing the heating flue horizontal level of the furnace between the heating temperature. An increase in the storage and charge a Temperaturunter-Heizzug Temperatur to z. B. over 1400 ⁰ C conditionally different from about 300 C prevail. Apart from that, however, a considerable complication of the operation 35 that with the lining according to the invention by the higher heat radiation. Since the known discontinuously operated coking ovens have a th brick lining made of chamotte and silica bricks, the temperature of this stress is only a shorter period of time. Keeping the furnace level, a shorter service life between the SiC-containing bricks and the charging furnace can also be expected. This means that the 40 kungsgut achieved in this way is at most about 30 to 40 ° C. Even a high increase in throughput only with a heat storage capacity of the masonry would be bought for the increased furnace wear. discontinuously operated coking furnace from