How to design Liquid Receiver Tank?

[Tothesky]

I need Engineering Practice for Design of Receiver Tank!
The Following is example as Design Condition.

- Inlet Flowrate of Liquid(Condensate of Steam) : Q [kg/hr] with Density d[kg/m3]
With above flowrate, how to decide Tank Size?

Above case in under Steady Sate Condition.
But, How about NON STEADY STATE Condition.

- Incomming Fluid as Liquid : Q [kg] with Density d[kg/m3] - due to Non Steady State, unit is only weight.
- Another Fluid(Water, H2O) as cooing media : C [kg] with Density dc[kg/m3]
With above incomming condition, how to decide Tank Size?

 

[LittleInch]

Could be anything.

Depends how much you want to store / how long it stays there before being pumped somewhere else

"Receiver tank" is a bit vague - implies some sort of pressure vessel, but you need to know why you have a tank and what is its purpose before you can make any judgements on size.

Generally design it as small as possible to save money / space / weight.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Tothesky]

Thank you for your confirmation.
As per your request, I try to inform you more.

Condensate Tank under Steady State Condition :
The Condensate Receiver Tank is to take condensates from other process equipments.
After taking Condensates, These condensates move to next process such as Boiler etc. by Pump.
I would like to know normal practice how to decide the size of Condensate Tank for this case.

Another Tank under NON-Steady Stat Condition :
This one is Intermittent Blowdown Water Receiver from Boiler.
D-type Boiler is consist of Steam Drum at TOP side and Mud Drum at Bottom side, and there are many tubes between Steam & Mud Drums for Heat Transfer.
But, in Mud Drum, there are many impurities like Mud due to Chemical Treatment(We can call Chemical Dosing System(Injection of Chemicals) for enhance of Water Properties.).
As you can expect, In Mud Drum, Impurities (Chemicals) accumulate, thus due to this reason, we have to remove Impurities from Mud Drum.
This removing activity is NOT performed under Steady State Condition, and The contaminated water having impurities is Blowdown Water.
Normally, this Blowdown water is under saturated condition.( Temperature is at Boiling Point.)
Thus, Before taking away this contaminated water, this water should be cooled by Cooling Water.
I would like to confirm Normal Practice how to confirm size of this intermittent Blowdown Receiver.

Thank you in advance.

 

[LittleInch]

The first vessel sounds to me like some sort of buffer tank, i.e. it can fill and discharge at different rates for a short time to smooth out the small fluctuations in flow and also act as single point for pressure and release of gas or steam.

So you need to work out what those differences are and how fast you can control/change the outgoing flow rate. If its very fast then your vessel can be small, if its quite slow then it needs to be bigger. There is no simple calculation here as it depends on how much range the tank has 10-90% or 40-60%?? and how much margin you want.

The intermittent drum clearly needs to be as big as the max volume of water and mud that you want to remove at any one time. Then add a suitable margin ( say 30%) to allow it to boil off and also the volume taken up by any cooling pipes.

again does the drum drain completely or is something left in it?


Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Tothesky]

Right! And, I fully understand!

For Condensate Receiver under steady state condition, I will consider The worst condition with considering many cases of Operating Conditions. And, I confirmed that The condensate receiver is Buffer Tank.

For Intermittent Receiver under Non-Steady state condition, I will consider Max. incoming quantity + 30% margin.

Thank you so much.
Moon.

 

[chicopee]

All receivers that I have seen in the US are build in accordance to ASME/NB code VIII unfired pressure vessels.

 

[MJCronin]

These people have been designing these special tanks for decades and can answer your questions ...

http://www.pennseparator.com/

Usually, when a boiler and boiler room accesories are specified, these specialty tanks are supplied by the boiler vendor.

If you have never specified these tanks before, you should know that there are other unique design features to consider.

For example, the condensate collection tank is usually subject to accelerated corrosion and material selection is important. If the tank is used in a situation where condensate sometimes returns "all at once" (i.e. a district heating system) it must be oversized. The relative placement of condensate forwarding pumps and the suction path from the tank to the pumps can be a constant source of trouble. The vent sizing for this tank is important also

The boiler blowoff tank can be quite small. It must be made from an erosion resistant material and have a tangential inlet.





MJCronin
Sr. Process Engineer

 

[Tothesky]

Dear MJCronin,

For Continuous Blowdown under Steady State, it's very small. I have experienced already.
But, for Intermittent Case (Non Continuous Blowdown)under Non Steady State, we should take account carefully.
This is only my simple opinion.

Moon.