4 replies to this topic

[farid.k]

I have one project that need to re-rout the steam venting 20 meters away from actual location. Concern is the actual location of steam venting is too short and might be dangerous to operator especially during windy day. Thus, one study has been done and final result is re-routing the existing venting extra 20 meters away from actual location. Some of the engineers raise their concern regarding to the existing pipe drain that should be re sizing back since actual vent piping has been resized. What say you guys?? For me, just maintain the size since the extension of the vent piping is not significant. My basis is, I just monitor the open drain area and the condensate flow is just droplets no point to increase pipe size let-say ½” to 1”. Let say need to resize the condensate drain, how do I estimate the flow of the condensate?  For me is hard to estimate the condensate flowrate since we don’t know how many per cent of  steam converted to condensate and for me, the only way to estimate accurately the flowrate of condensate is by collecting condensate at the open drain with respect to the time. Am I right? Appreciate others to comment. refer attachment for sketch. Thanks guys.

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[Padmakar Katre]

Hi farid,

 

Please tell us the system details such as:

1. is it normal & continuous operation?
2. What is steam pressure level?
3. Is the vent line insulated?
4. What is the vent rate/hr?
5. Possible option is to condense whole steam and use condensate as make up BFW to existing boilers

[farid.k]

Hi Padmakar,

 

The system details are as follows:

1. The operation is continuous;
2. The vent line has a control valve for controlling steam pressure;  The pressure upstream of the control valve is 8 barg.  Downstream pressure is atmospheric;
3. The vent line is insulated;
4. The Steam is vented at a rate of  2,870 kg/hr;
5. The option to condense all of the steam and use the condensate as make up BFW to existing the boilers is not possible (budget constrain) since we have to buy a condenser and it requires more piping to route back to the boiler.

[himant]

Hi Farid

 

I have two queries

1. Why there is a requirement of continuous drain line if the vent is with no pockets?

2. Can't we install a steam trap?

 

Moreover, it is very hard to imagine that venting is continuous in this energy crisis world.

 

If it is not continuous, condensate formation rate can be calculated by assuming that initially vent is at atmospheric temperature and steam condensation occurs till warm-up time

 

Regards

Himant

[Ajay S. Satpute]

Farid,

 

In Hysys, you can simulate the pipe segment with insulation details to get the heat lost to atmosphere by steam. It'll also provide you the steam quality downstream of the pipe. Consider the winter night temperature as ambient to get the max. calculated condensate.

 

If existing system is working fine, then the modified one might run fine as well, for there is not much change in the system. However, it is better to calculate.

 

How you are making sure steam does not leave from the drain? Is there a seal/trap at the drain line?

 

 

Regards. 

 

Ajay S. Satpute