Flash tank design for 30mw cpp.

[ervarun]

Dear all ,

i m new to this site, i donot know how i have to post correctly , well i have some prob at my workplace as i m working with an air cooled condenser company , we are OEM of ACC. now in our unit flash tank is included in our scope of supply with acc , but all the drain and all comes from T.G Building side at different temperature and pressure .when its comes in a common tank , for equal pressure and reducing the temp some flash will produce its nothing but steam ,and the condensate will drain from the tank and steam will go from flash tank vent to steam duct . now my prob is that turbine manufacturer give me all the drains data and ask me to design the flash tank as its comes in pressure vessel , i never ever try to design like dis . so i guess someone already work on this kinda vessel and help me out defiantly ...

please give me some references so that i will go through it and try to start with something .

HOPE FOR THE VICE REPLY ...

[A.Venugopal]

Dear friend ,

For design of a flash tank you should have the incoming condensate flow and temperature and required pressure and temperature of flah. (Appraently you seem to be planning to vent out to atmosphere, this is inadvisable ) Please post the input information as above so that the flash vessel can be sized. If you would like to give it a try your self , please reach forbes marshal web site , you will get some procedures. You mayalso contact me at avgpaul@gmail.com

Best regards

Venugopal

[ervarun]

Dear A.Venu

actually there are drains coming in flash tank header is in the form of superheated steam , saturated steam and condensate ,

i will upload file tomorrow of all the flow with temp , pressure , flow and enthalpy .

one more thing that we are not vent it to atmosphere the flash will go to our unit steam duct which is operating in vacuum at .2 ata and 58.1 degree .

and the drain of flash tank will go to hotwell tank or condenser tank.

let i collected data tomorrow and upload here ..

[ervarun]

please check the detail of drains for flash tank and help me out to design it .. or give me some reference to do so ???

[viswanathankasi2]

any further details, pl. upload

[ervarun]

what r the other input is reqd please tell me so that i can gather the information as soon as possible ...

[viswanathankasi2]

refer this book "ASHRAE HANDBOOK"

[AnandV]

You will have to calculate the quantity of flashed steam first.
For this you need
(a) working poressure of the flash tank
(b) Flow & Temp parameters of the inlet drains,

there is a chart [

[link Point to another website Only the registered members can access]
Once you know the quantity of flash steam Q (Cum/sec), you can calculate the dimension of the vessel by fixing the velocity V of steam to a safe value (refer some handbook for this). It shoud be around 2-3 m/sec.
Area of vessel = Q/V
after getting the dia of the vessel i think it would be easy to get other parameters

[A.Venugopal]

Dear all,

I am awfully sorry that my intended reply was delayed due to preoccupation. Thanks also to others , the resources in Ashrae handbook, and spirax sarco charts help to calculate the flash vapor qunatity , but you can also do it from fundamentals by working on the enthalpies. The vessel size is by velocity of vapor , it is , at the operating conditions is 4 m/sec , yes , Mr Anand suggested correctly. Please find attached the calculation sheet. You need to add a common header amply dimensioned before the flash vessel to homogenize the different condensate streams .Vessel is to be designed for full vacuum . Frankly in a commercial installation the whole design should better be done by some one experienced , Mr varun may please note what ever is being advised is for academic purpose.

Best regards

Venugopal