Q & A > Question Details
03/11/2010 A: J Sudeep, SATORP REFINERY, jsudeep81@gmail.com
For top fired
Smaller surface area per unit volume when compared to geometry of side fired &
Single operating level for burner access
High heat flux available at inlet for highest endothermic reaction to occur
Simplified combustion control due to eliminating zone firing,burner maintenance cost is reduced
The main disadvantage is Burner access located in a hot environment, operator cannot stay for long time heat radiation hazard is more
Flame imingemnt possible for multiple tubes at single time.
Side fired
Most of ammonia /urea/methanol plants are side fired
side fired requires 4-5 times more burners than top fired, this makes difficult in operations
maintenance cost is high
online burner cleaning possible
06/06/2010 A: Balasubramanian Iyer, Nexen CNOOC Limited, balasubramanian.n@aol.in
Advantage depends upon the capacity of plant. If the plant capacity is very high then top fired reformer helps as the number of tubes goes up and in side fired reformer the no of tubes is pinch. Operation-wise side fired reformer provide more uniform temperature than the top fired. Again the plant size matters for large capacity plants the top fired reformers are generally preferred as the space they occupy is less compared to the side fired. Again the number of burners required for the heat input considerably gets reduced in Top fired reformer compared to side fired. So the benefits are not general it depends upon the consumer on validating various points like plant area, plant capacity, operational easiness, etc.
16/05/2010 A: Syamantak Dhar, Indian Oil corporation Limited, syamantak.dhar@aol.in
In Side fired Reformer (Generally Halder Topsoe Design) there is always a possibility of direct flame impingement on the tube specially while running at higher T'Put. In case of Top fired Reformer the above possibility is greatly reduced but not eliminated. In Top fired Reformer impingement can occur and the possibility increases when the amount of Hydrogen in PSA off-gas increases.
In Side fired Reformer there is always option of manipulating the Pre-heat of the Pre-Reformer and also there is a control while running at moderately low T'Put. The advantage of this running at moderately low T'Put with side fired Reformer is that since bulk of the conversion and hence the endotherm occurs at the top part it is always possible to put the burners at the lower elevation on minimum duty to have uniform skin. The same can't be achieved with Top Fired Reformer Tubes.
14/05/2010 A: Nitin Mittal, HPCL Mittal Energy Limited, mitnit73@yahoo.co.in
In my experience problem of hot spot and flame contact with tube is more severe in side fired tube.
But side fired reformer gives advantage of better tube temperature measurement thus better tube life and uniform temperature control.
13/05/2010 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
Your furnace designer (licensor?) will have a claim for you to evaluate.