Search results for query: *

The stainless cladding is on the OD. These tubes are cracking from the ID out. Stainless cladding is fairly standard on Chemical recovery boiler furnace tubes.

MetEngr, We are in the process of doing several metallurgical analysis both internally and a third party. I was hoping to find others that have experienced similar failures in case the metallurgical analysis proves inconclusive. It appears that high residual stresses play a key role...

These are 3" to 2 1/2" swaged tubes. They are composite tubing in a chemical recovery boiler (carbon steel with a stainless cladding). These are furnace wall tubes. In the 3" area the tubes are tangent, in the 2 1/2" zone there is a 1/2" membrane between tubes.

We have an installation that has swaged tubes installed in the lower furnace. Recently we have experienced some failures of these tubes. The boiler rep is pointing towards possible water treatment issues, however, we have had no failures away from the swaged tubes. The tubes were not stress...

I have long believed that elevated copper levels in feedwater is bad. What I am ignorant on is the damages that may result in boilers from 600 psig to 1500 psig. Any information on this subject would be appreciated.

The source of the copper has been indentified however there is some debate internally as to how damaging the copper actually is to the boiler.

I have long believed that elevated copper levels in feedwater is bad. What I am ignorant on is the damages that may result in boilers from 600 psig to 1500 psig. Any information on this subject would be appreciated.

The unit is currently on line. So the steam coil itself is not accessible. They are trying to determine condition prior a scheduled outage.

Is there any way to quantify a leak based on lost pressure. A SCAH being pressure tested with air to 25 psig. Over a two hour period the pressure decays slowly to 5 psig. Is there criteria for how long pressure must be held to determine if there are no or no significant leaks leaks? I was...

The control strategy I suggested was just the basic strategy used. In some similar strategies I have seen integral only controllers utilized and some DCS vendors permit you to have gain but set them for integral action on setpoint changes. This would prevent the sudden jump in steam flow with...

I have seen control strategies where the steam flow setpoint is set based on the amount of water to evaporate. These evaporators have a varying amount of solids (suspended and dissolved) and the amount of steam is changed based on flow rate and percent solids. This would be a course...

Does anyone know how much subcooling is possible (typical) in a sweetwater condenser? Steam at saturations (534 Deg F) with feedwater entering in at 350 Deg F. Our design shows very little however we have about 150 Deg.F subcooling right now. Of course this may indicate a leak, however, the...

The proper procedure is to open fully the valve closest to the boiler and then the down stream valve. When closing them it should be done in the reverse order with the furthest valve being closed first. If the installation is proper the down stream valve will be designed for throttling while...

The location of the injection point is dependent on the flue gas temperature. The amonia to NOx reaction happens in a certain temperature range. Amonia injections systems I have seen typically have the injection point in the superheater section.