huangyhg

brick masonary chimney for coke oven plant
i am looking for a suitable design of 50m high chimney of brick masonary to discharge hot gas of 1000 deg. centigrade from coke oven plant.
the problem is that i will have to provide air gap of 100mm between the inner heat resistant fire brick liner and outer red or ordinary brick shell.
p. sarcar
well, i can help a little bit:
you are looking for someone who does "stack" design.
i haven't come across too many stacks whose exterior was constructed from masonry . in fact, i can't think of one. if it's freestanding, you'll end up with a huge moment at the base. usually what i see are constructed from steel with firebrick lining.
psarcar, why so high. 164ft? i haven't ever seen them that high. can't see why it would be any different than one that is 40ft tall though. the gap shouldn't be an issue. it is just a space you have to leave between the two bricks. good luck.
i think it would be best to work with someone that has the experience in this specialized area. the differential temperatures between inner and outer on a tall stack could pose some very unique problemsand approaches.
all "hot chimneys" (steel or brick exterior) have fire brick in common. there are very few firebrick manufacturers, but they would work closely with the structural engineers. try contacting one or two for leads.
dick
i agree with all the advice above. this is a specialized design and not something to learn on your own. however, if you need a reference to see what's going on, gaylord and gaylord's "structural engineering handbook," 1st edition, chapter 26 has recommendations.
real problem with thermal expansion between the two wythes...
could be in the order of a foot or two...
dik
all the advice above is good. traditionally, the design and construction expertise for this type of industrial structure has been tightly held within the central engineering departments of large industry and a small number of consultants. don't know your situation, but you must insist on experienced assistance.
the foundation design for the overturning moment due to wind or seismic forces and the flexural strength in the bottom of the stack will be designed for the same moment/shear. i tried a few ideas and could find no unreinforced masonry of normal dimensions that could produce the required strength.
i think you need the design guides of the cicind (international committee on industrial chimneys),
i am an expert in high rise rcc and steel chimney. i have developed software for rigorous analysis, design and estimate of both rcc and steel chimney. the analysis considers all structural calculations not only for static loads at various construction phases but also dynamic load due to wind excited oscillation for varios modes of vibrations and frequencies. the said software also design full circular or annular raft foundation and also pile foundation. hence design of a chimney is a matter of half an hour for me because the software can take decision automatically for required concrete grade, thickness of concrete or steel shell and optimum percentage of reinforcement, metal strappint details of inner liner etc leaving little scope for my perpetual decision.
design of brick chimney is also not difficult for me because any brick masonary work and their joints can take 1 kg/ sq. cm of tensile stress. hence for any moment at any height of the chimney if the moment of inertia of the circular & annular shell of brick chimney is right enough for allowing 1 kg/ sq. cm of tensile stress on the windward side of the masonry then the chimney is designed.
but my query was how to support the inner refractory brick lining allowing for 100 mm airgap (with fresh air inlet at bottom and air outlet at top to allow for dissipation of heat between liner and external brick shell) between lining and outer brick shell for inner temperature of about 800 to 1000 deg. c. if any body has designed such brick chimney for industrial plants like coke oven plant(in a steel plant) then let me know.
sarkarfff">,
i again have to refer to a tv program i saw recently where they were building such a chimney. if i'm not mistaken they were installing a spacer between the liner and chimney a some intervals. this particular job was quite large and they didn't appear to using anything approaching standard masonry dimensions.
i'll try to dig through the tv listings to see if i can find a reference to the show.
the is/was a company in that had fatal accident, fire, while building a masonry stack in (west virginia). i read recently that they had been bought out.

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