8 replies to this topic

[jigs1403]

hello everyone,

In my plant steam which flows in one of the reboilers from steam drum is not remaining constant...i mean flow varies continuously from 1 ton to 4 tons per hour inspite of same pressure of steam drum.....so i am not able to maintain the temperatures in CO2 regenerator.. please me the problem and solution..

[Art Montemayor]

Jigs:

We can't give you a problem; however, we can help you solve it.

But first, you have to help also, by giving us all the required basic data to solve it. We need a complete description of what you are dealing with: a sketch - preferably a P&ID of your system, showing how you are supposed to have the steam reboiler supply controlled. We have to be able to spot the problem area; the solution is probably very simple and easy to resolve.

Finding the problem is always the tough part. Finding a solution is often easy.

Await your reply.

[jigs1403]

hey thanx budy.... i would provide all the necessary details as soon as possible.... thanx again....

[jigs1403]

hey budy u must b remembering me posting 1 problem abt steam flow to reboiler few days ago...now here i am going to share few detail with you..
Basically my plant is Synthesis gas producing plant...
with help of 3 superheater coils,we superheat the steam coming in these coils from Steam drum..at about 38 ata and 248 C. Now these steam gets superheated in these coils.. these steam goes to get mixed with feed and other part goes towards Steam turbine... now still some amount of steam is left... n these superheated steam was converted to about 5 ata pressure by a control valve... and then it is quenched by water to about 145 C to get into saturated form before it enters steam reboiler....also the superheated steam which looses its heat after passing through turbine is at 5 ata and it is also quenched....

Steam which goes to Steam turbine is abt 300 C....

Flow of steam required to steam reboiler which reboils GV solution is abt 3.5 T/hr....

so now can u help me?

[katmar]

My guess is that it desuperheater problem. Do you monitor the pressure and temperature of the steam fed to the reboilers?

[jigs1403]

ya pressure is 5 ata and temp is around 150 C.............. and we don't have any desuperheater..........

[katmar]

The apparatus that you describe as "quenching superheated steam with water" is usually known as a desuperheater. If this is not controlling steadily and superheated steam is being fed to the reboiler it will significantly affect the heat transfer coefficient and therefore the steam flow rate.

[jigs1403]

But there is no appartaus which does the quenching in our case...there is just 1 Temperature Control valve which controls addition of Boiler feed water to Steam 4 quenching..so there is no desuperheater....

[breizh]

Hi Jigs1403,
As suggested you should pay attention to the quality of the steamand the document attached should also support your query http://www.spiraxsar...ater-types.asp.

Breizh