Previous in Forum: Emulsion Silo Design   Next in Forum: Cleaning Of Powder Detergent Tower
Close
Close
Close
19 comments
Active Contributor

Join Date: Apr 2012
Posts: 22

Steam Traps

05/08/2012 4:25 AM

my plant needs steam for process heating,after steam passes the heat exchanger it is pumped back to the boiler through condensate return pumps.My bosses removed the steam traps(before i started working there)and nw i need to make them understand why steam traps are required.How is the efficiency of the steam circuit reduced when steam traps are not available

Register to Reply
Pathfinder Tags: steam traps
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru
Popular Science - Weaponology - New Member United Kingdom - Member - New Member

Join Date: May 2007
Location: Harlow England
Posts: 16499
Good Answers: 662
#1

Re: steam traps

05/08/2012 4:28 AM

Tell him it will save money. It's the only thing they understand.
Del

__________________
health warning: These posts may contain traces of nut.
Register to Reply Score 1 for Good Answer
Guru

Join Date: Feb 2006
Location: Piney Flats, Tennessee
Posts: 1740
Good Answers: 23
#15
In reply to #1

Re: steam traps

05/10/2012 12:31 AM

you know them all to well lol

__________________
If you never do anything you never have problems.
Register to Reply Off Topic (Score 5)
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 30332
Good Answers: 818
#2

Re: steam traps

05/08/2012 4:36 AM

Without the traps, instead of all the latent heat in the steam being released to the heated surface, some of the steam will appear at the condensate return pumps' inlet. As the pumps increase the pressure to push the condensate back to the boiler, the steam bubbles collapse, eroding the impellers of the pumps until they fail to pump. Once they fail to pump, the steam system will flood with condensate and the heating process will fail, with knock-on impact to product throughput and quality. So the net effect of removing the traps is higher energy usage, lower product quality and quantity, and higher maintenance costs in the condensate return system.

It's the top a slippery slope towards economic closure of the facility and the loss of jobs.

Do re-install the traps.

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply
3
Power-User
Engineering Fields - Piping Design Engineering - New Member Engineering Fields - Mechanical Engineering - New Member

Join Date: Aug 2008
Location: Europe
Posts: 287
Good Answers: 27
#3

Re: steam traps

05/08/2012 6:17 AM

Give your "bosses" a simple example which their apparently almost vegetable-like minds might understand.

Tell them to instruct their doctors to remove their entrails. Because, after all, they're of no use. They simply take up room and create maintenance headaches. Don't forget to say that they're inefficient because they hamper the rapid progression of food from their mouths to their brains at the other end of the line.

But wait a minute: You said that the "steam" is pumped back to the boiler through condensate return pumps. Obviously, you must have meant "condensate". Therefore, some sort of steam/condensate interface does indeed exist. Is your plant a paper mill with drying cylinders and typical condensate level controllers? If that's the case, you don't need traps.

Neither do you require traps if the heat exchanger is so woefully undersized that it's perpetually flooded with condensate even at the lowest process loads.

There seems to be missing information in your works...

__________________
Best regards, HeviiGuy
Register to Reply Good Answer (Score 3)
Guru

Join Date: Nov 2007
Posts: 519
Good Answers: 11
#14
In reply to #3

Re: steam traps

05/09/2012 9:05 AM

I'm going to add on here because you seemed to cover the main points .

Steam traps protect the pipe and system by releasing the condensate from the system. Condensate causes bad corrosion issues and water hammer as it travels long lengths of pipe. It also protects the system because typically a system designed for steam service doesn't quite operate the same when condensate is present lol.

Get an Armstrong catalogue and read the literature at the beginning. It will give you all the detailed reasons on why you should steam trap steam systems.

To give you an example that might help your cause...last year I was in charge of a group that was tasked with maintaining the steam system in the plant. They basically just fix steam leaks and steam traps. We spent about $350,000 on the year for labor and materials and saved about $1,500,000 in lost steam/energy. The pressures on our lines were anything between 30 psi to 600 psi. Bigger pressures mean bigger savings.

Register to Reply
Guru
Hobbies - CNC - New Member Hobbies - DIY Welding - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2007
Posts: 22699
Good Answers: 410
#4

Re: Steam Traps

05/08/2012 7:49 AM

And your bosses are.......... the owners nephews, maybe??

Steam releases it energy when it changes from a vapor to a liquid.

This little description may help

Here are some excellent links, where you can research:

http://www.armstronginternational.com/steam-traps

and

http://www.spiraxsarco.com/

__________________
“ When people get what they want, they are often surprised when they get what they deserve " - James Wood
Register to Reply
Power-User

Join Date: Oct 2009
Location: Central Midwest
Posts: 450
Good Answers: 38
#5
In reply to #4

Re: Steam Traps

05/08/2012 9:05 AM

No Phoenix, the bosses are MBAs.....

And, like all MBAs, none will take reponsibility for the removal of the traps.

__________________
We have met the enemy....and he is us. POGO
Register to Reply
Guru
Hobbies - CNC - New Member Hobbies - DIY Welding - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2007
Posts: 22699
Good Answers: 410
#6
In reply to #5

Re: Steam Traps

05/08/2012 9:21 AM

They can pass for nephews.

Except, one nephew was talking about getting his MBA also.

I told him, I think it would be wiser for you to get your undergraduate degree first.

His response was, that was a waste of time.

dumb ass.

__________________
“ When people get what they want, they are often surprised when they get what they deserve " - James Wood
Register to Reply Off Topic (Score 5)
Guru

Join Date: Oct 2008
Posts: 42294
Good Answers: 1662
#7
In reply to #5

Re: Steam Traps

05/08/2012 9:26 AM

And the disclaimer comes from their lawyers,

Register to Reply
Guru

Join Date: Dec 2006
Location: Hop around Toronto, New York & Karachi
Posts: 1878
Good Answers: 19
#8

Re: Steam Traps

05/08/2012 11:50 PM

Your management should remove your boss because his action has/is caused/causing thousands $ losses in fuel bill & delayed heating. If you management cannot do this/your boss the owner/his son then change job.

__________________
I not only use all the brains that I have, but all that I can borrow. Woodrow Wilson
Register to Reply
Guru

Join Date: Jun 2008
Location: Oman
Posts: 612
Good Answers: 14
#9

Re: Steam Traps

05/09/2012 12:25 AM

When these traps were removed?

My be your superior may have removed it to upgrade it with new one. Check with him

If he is a non-technical person you need to explain him in common man language i.e. in terms of cost.

Register to Reply
Guru

Join Date: Dec 2006
Location: Hop around Toronto, New York & Karachi
Posts: 1878
Good Answers: 19
#10
In reply to #9

Re: Steam Traps

05/09/2012 12:41 AM

He can take the horse to the water but he cannot make him drink.

Just last week I came across a similar case with 3 sets Canning Retort being operated with 1 bar steam pressure (Pressure/Temperature Modulating Control Valve installed) and a lift from the Spirax 2" FT14-4.5 bar steam trap of 4 metre to the overhead condensate return main (also tapped with several high pressure condensate return from steam headers). Due excessive water logging with no back pressure available to lift the condensate, the operators would open trap by pass to speed cooking and finally the Production Manager ordered to take off the steam traps to prove that the result is better off without steam traps.

I recommended to disconnect the steam trap lift, fit the 2" steam trap back again and take the condensate at floor level to a Condensate Pump (in a pit/outside the Dept. which is at a lower level) to pump back to boiler house.

__________________
I not only use all the brains that I have, but all that I can borrow. Woodrow Wilson
Register to Reply
Power-User

Join Date: Oct 2010
Location: Base in Madrid, Spain. Updated location every several months.
Posts: 126
Good Answers: 3
#11

Re: Steam Traps

05/09/2012 1:28 AM

Nice link!

__________________
Everyday learning.
Register to Reply Off Topic (Score 5)
Power-User
Engineering Fields - Piping Design Engineering - New Member Engineering Fields - Mechanical Engineering - New Member

Join Date: Aug 2008
Location: Europe
Posts: 287
Good Answers: 27
#12

Re: Steam Traps

05/09/2012 2:36 AM

They don't need restrictive orifices ; It seems that they're already quite capably throttling the flow of condensate so that it floods the upstream as such devices are wont to do. And, they're doing it much more effectively since by adjusting the discharge port manually, they have at least a modicum of control during process fluctuations. These orifices as suggested can't do that: They're simple static holes in the return flow .

Unless labour is so cheap in the OP's part of the world that his bosses can afford to have somebody sitting at the discharge end of each heat exchanger all day long, opening and closing the outlet valve so that the steam/condensate interface is controlled regardless of process load, they need "real" steam traps.

__________________
Best regards, HeviiGuy
Register to Reply
Guru

Join Date: Dec 2006
Location: Hop around Toronto, New York & Karachi
Posts: 1878
Good Answers: 19
#13

Re: Steam Traps

05/09/2012 2:51 AM

twanda, check my thread#11. maybe the heat exchanger became undersized or the steam trap was not designed for the condensate load and was under capacity. Maybe the steam trap was Thermodynamic (wrong) and not Ball float/Inverted Bucket type? Maybe the trap was installed by just pipe size and capacity was not considered? How old is the heat exchanger? Is it with TCV? Was the condensate first lifted without pump? When was heat exchanger tube last cleaned? Has it fouled badly? Is the condensate coming rusty? Too a many questions to ask and answer.

__________________
I not only use all the brains that I have, but all that I can borrow. Woodrow Wilson
Register to Reply
Active Contributor

Join Date: Apr 2012
Posts: 22
#17
In reply to #13

Re: Steam Traps

05/11/2012 4:03 AM

it uses the traditional thermodynamic steam traps,heat exchanger is changed every 4 years mainly if leackages start to develop,fouling non,condensate not rusty. i now dont no hw i can rate the steam trap and determine wether it was to capacity o not.

Register to Reply
Guru

Join Date: Dec 2006
Location: Hop around Toronto, New York & Karachi
Posts: 1878
Good Answers: 19
#19
In reply to #17

Re: Steam Traps

05/24/2012 2:24 PM

Twanda - A TD Steam trap is the WRONG type to drain Heat Exchangers because it is intermittent discharge capacities and poor air venting facilities. The steam traps hold backs condensate at every off-cycle water-logging the heat exchanger's steam coils. When this happens the temperature of the heating fluid drops/time increases so the by-pass is opened to speed up heating. The air inside is Oxygen which mixes with condensate CO2 and forms ferric-oxide which eats up your pipes/tubes and the causes leakage. This is why every 4 year /so the heat exchanger is replaced.

The ideal Steam trap is ball Float with inbuilt Air Vent. Spirax FT14-4.5TV ideal(if steam operating pressure 4.5 bar) or Spirax FT14-10TV (10 bar)

You must first calculate the condensate load with formula :

Q = Gpm x delta T F x cp x 500 x sg/LH

Q = steam lbs/hr . delta T =Final temp f minus inlet fluid temp F

cp = specific heat, sg = specific gravity

LH = latent heat at the operating steam pressure psig

Example: say you want to heat water 50 gm from 40f to 140F at 15 psi

Q = 50 x 100 x 1 x 500 x 1 /945 = 2645 lbs/hr steam x 2 (safety factor for startup load) = 5300 lbs/hr.

Now size a Ball float Steam Trap (Spirax/any make) to discharge 5300 lbs/hr at 15 psi. whatever size (1/2" thru 2") comes is the RIGHT size.

Based on this you work out your capacity and size of steam trap for your heat exchanger.

__________________
I not only use all the brains that I have, but all that I can borrow. Woodrow Wilson
Register to Reply
Guru

Join Date: Feb 2006
Location: Piney Flats, Tennessee
Posts: 1740
Good Answers: 23
#16

Re: Steam Traps

05/10/2012 12:38 AM

Wait until they have a meeting and want to discuss how they can operate the plant better and save money.

There is your opening. Have all you evidence need to show how much fuel or power is wasted. Also ask about any past problems with the water supply, contamination, filtering or problems with the boiler that required the traps to be removed.

Often if it is not broken fixing it seems like a waste too. If it never rains why fix the roof ?

__________________
If you never do anything you never have problems.
Register to Reply
Guru
Engineering Fields - Mechanical Engineering - New Member

Join Date: May 2008
Location: CHENNAI, TAMIL NADU, INDIA.
Posts: 1854
Good Answers: 64
#18

Re: Steam Traps

05/24/2012 12:09 PM

Dear Mr.Tawanda,

In addition to the comments from CR4 Members, I want to say the following.

Apart from the Heat Loss the condensate is bound to escape which is treated water - may be through DM plant or RO Plant-which is a costly affair.

You have not mentioned the boiler/steam pressure. The higher the pressure - the higher will be the quality of feed water.

Ultimately severe loss interms of efficiency, fuel and chemicals for the feed water.

DHAYANANDHAN.S

Register to Reply
Register to Reply 19 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

abelmh (1); BoltIntegrity (2); cingold (1); dadw5boys (2); Del the cat (1); dhayanandhan (1); ducon (4); lyn (1); MJCronin (1); mrswamy (1); phoenix911 (2); PWSlack (1); tawanda (1)

Previous in Forum: Emulsion Silo Design   Next in Forum: Cleaning Of Powder Detergent Tower

Advertisement