Steam Flowrate Conundrum 5

[HopDr]

I have a plate heat exchanger designed to consume 2533 lbs of steam per hour at 249 deg F (roughly 14.5 psig). My boiler (under ideal conditions) delivers steam to this HX at ~338 deg F, 100 psig, through a 1" sch. 40 line. I'm trying to determine how many pounds of steam are actually being delivered to the HX per hour, as its symptoms indicate that it may be starving for steam. I don't know definitively the steam velocity at the HX, but Spirax-Sarco tables indicate that it should be no more than 131 fps. At this velocity & 100 psig, the same table indicates that the 1" line can deliver no more than 736 lbs/hr.

Another engineer feels that frictional losses (total equivalent length) in the 1" line will introduce roughly 20 psi pressure drop between boiler & HX, which will somehow cause flowrate to double to ~1400 lbs/hr & the velocity to increase to near-sonic. I've tried mightily to cipher out the physics for this to be true, as he has more experience at this than I, but I'm boggled!

Perhaps someone can address a question basic to my friend's position:
1. In a closed system such as this, does steam accelerate between its constant-pressure source -- the boiler -- & the point of lowest pressure -- condensation inside the HX -- or does it move at a constant velocity for a given pipe diameter?

Any feedback is greatly appreciated!

 

[osoloco]

in reference to the formula by Chicopee:
it is (area)*(density)*(velocity)=(mass-rate-of-flow),
with a guess at the velocity.