Problems with sleeve fluidization air
Thread Content
After the flow of fluidizing air in the sleeve is interrupted, the emergency steam for the sleeve is put into use. Can this emergency steam be used as a fluidizing medium for an extended period of time?
Is it necessary to put it into use? Most of the devices have been removed!
Whether the fluidizing steam for the sleeve is cut off or not, its prolonged use can easily affect the pressure in the settler; if the steam temperature drops significantly, sludge formation may occur.
It’s not allowed; that’s just accidental steam. It’s okay for a short period of time, but it’s not permitted over an extended period. The most critical point is that if accident steam is actually used, it indicates that there is a problem with production; prolonged use of the catalyst can lead to thermal runaway, as well as the activation of sludge.
The situation you are referring to is likely a coaxial catalytic device. Steam definitely cannot be used for a long time. It is possible to use purified air as a substitute
The catalyst inside the sleeve comes from the stripping section, so it is in a condition similar to that of the gas phase; it should be feasible to use it. The main issues may be, first, increased operating costs, and second, the increase in water vapor concentration in the flue gas having an impact on the subsequent units, especially the waste heat boiler.
Emergency steam is used only in emergency situations and can be applied for a short period of time; if a problem arises and cannot be resolved within that short time frame, such as a brief interruption in the fluidization air supply for the sleeve； Production should be maintained at reduced levels; if recovery is not possible over an extended period, the feed supply should be stopped ； Currently, many units employ the addition of unpurified air behind the sleeve-type fluidizing air; in the event of an interruption, the flow control orifice bypass for the unpurified air is quickly opened to ensure catalyst fluidization ； Prolonged use of accident steam can degrade the performance of the catalyst; low temperatures can also cause the steam to contain water, leading to slurry formation and thermal collapse ； ,
It can easily lead to thermal failure of the catalyst; an excessive amount of fine catalyst powder, along with poor removal, can affect the flue gas turbine. Moreover, it will cause the hydrothermal deactivation of the catalyst. It will also affect the pressure of the regenerator.