Will fuel gas catch fire spontaneously at 750 degrees?
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The process interlock of a cracking furnace indicates that at 750 degrees Celsius, the interlock between the flame detector and the igniter is bypassed; this is because at such a temperature, the fuel gas already catches fire on its own, right?
Combustion requires temperature, fuel gas, and an oxidizing gas. The ignition point can only be determined by knowing the composition of the fuel gas. Even with a ignition point, oxygen is still needed for combustion
Without oxygen, there can be no combustion; otherwise, what would happen to hydrogen production reactors?
With our stove, at this temperature, it lights up as soon as the gas valve is opened
Without an oxidizer, it cannot burn even at high temperatures
The company’s hydrogen production converter is equipped with an interlock: when the furnace temperature drops below 750 degrees and the combustion detector fails to detect a flame, the furnace or the interlock shuts down the system. The principle was explained upstairs. Above 750 degrees, the fuel gas (natural gas used) has a auto-ignition temperature of over 538 degrees, and the fuel will burn spontaneously through the burner. Ensure safe combustion in the furnace. There is also interlocking for the combustion air; if the air/fuel ratio falls below a safe value, shutdown will also be triggered via interlocking.
The ignition temperature of natural gas is 540°C, a temperature at which it can ignite spontaneously
This post was last edited by longziyun on 2018-9-18 at 13:26. The original poster should have posted this question in the petrochemical deep processing forum; most people in that forum are not from the ethylene industry, and they don’t have a good understanding of the operation of tube-type cracking furnaces, which are the key equipment used in ethylene production. As a result, their answers might not be relevant to the question. A tubular pyrolysis furnace is a flame-type gas furnace; there is no such thing as a furnace that operates without oxygen. In a normal furnace, the COT temperature inside the tubes needs to be above 800°C, while the temperature in the furnace chamber should also be above 1000°C. The fuel gas used by manufacturers is mainly methane, whose auto-ignition temperature is 540°C. Therefore, a shutdown mechanism at 750°C is necessary and quite normal.
Pyrolysis furnaces and conversion furnaces represent the highest level of heating furnaces. The cracking furnace requires regular coking of its furnace tubes, and the waste heat boiler sometimes needs hydraulic coking. So it has a higher start-up and shutdown frequency than converter furnaces. Sometimes it needs to be started and stopped once every month or two. Typically, a tubular pyrolyzer is equipped with an exhaust fan that is activated to facilitate ventilation before ignition, and then, similar to a conversion furnace, the temperature is raised through ignition. The security considerations are similar.
Yes, it is an acid regeneration unit, and the temperature is indeed 1000 degrees