I`m an old navy BT. I`m a pipe fitter/welder these days. I teach a steam class at an apprenticeship school. Your youtube videos are priceless for visual aids. Thank you so much and please keep up the good work guys, Bravo Zulu!
My DA tank is banging after the cold water feed valve shuts. The pressure goes from 5 psi to 3 psi and seems like it goes into a vacuum. It’s a Bryan tray type. My other DA gets its feed water from the surge tank so the water is preheated so there is no shock. How do I get rid of the banging
Overall, a good video. A couple of nits need picking, however. 1. The deaerator (DA) is a direct contact heat exchanger where steam and liquid come in direct contact. This raises the temperature of the condensate sufficiently to allow non-condensable gases to be liberated. As the DA supply steam is regulated to maintain the shell above atmospheric pressure, the gases flow naturally through vents into the atmosphere along with a small amount of steam. 2. Cavitation is the result of the pressure at the "eye" of the pump impeller falling below the saturation pressure for the liquid being pumped. This creates steam bubbles that travel with the liquid toward the discharge (high pressure end) of the pump. When the pressure exceeds the saturation pressure, the bubbles collapse. It is the collapsing bubbles that cause the sound like "pumping rocks." Think of the sound of clapping your hands together. The walls of the bubbles (incompressible liquid) coming rapidly together, makes the noise. At the same time, these little "shock waves" impinge upon the impeller and slowly "jack hammer" the material away. This is what Net Positive Suction Head (NPSH) is all about and why the DA is normally installed at an elevation significantly higher than the feed pump suction. The static head of liquid in the DA and the low-low DA level switch protect the pumps from this damaging phenomenon.
Appreciate your response and while everything you say is technically correct we try not to get too deep in the weeds with these videos. If it gets too technical then we tend to lose our audience. Giving them just enough information so that they know why things happen but not so much that we lose their interest is a balancing act that we have to do on all of these videos. Our Boiler University gets into the weeds, real deep. That is where we take the time to explain, in detail, all of the points you make plus much more. Hopefully that makes sense. Again, really appreciate your feedback and you continuing to watch our videos.
What is the minimum size boiler you would use a deaerator on? At smaller sizes i would imagine a Spirovent or Pot Feeder of Oxygen Scavenger would make more economic sense? I haven't seen deaerators on small residential or small apartment building applications but that may be my limited exposure.
Thank you for the detailed info!! I have a quick question...I understand that the oxygen will be removed from the feed water before it goes to the boiler. so can water stay in liquid state if 'O’ is removed from H2O? Please help me understand. Thanks!
100% agree! Realizing your boiler room is a system rather than just the boiler is a really good step in understanding problems you could be having. Thanks for watching and commenting!
I was asked on my L.A. Steam License exam to name five purposes of a D.A tank and everything that I have read, gone to classes on they only mention three, which you guys went over. 1. Preheats the boiler feed water. 2. Removes oxygen. 3. Act as a storage tank. What would be the other two purposes?
Two other purposes of the DA could be that it removes carbon dioxide and recovers flash steam returning with condensate. In a vented receiver this would be lost. Hopefully that makes sense! Thanks for watching and commenting!
Pre heat cond return, pre heat make up water, remove noncondensables from make up water, remove noncondensables from cond return, and store feedwater. Theres 5 lol ;) get technical
Haha thank you. I passed, this is what they wanted to hear incase anyone else needed some help! 1.) It is a preheater for Boiler feedwater 2.) Removes Oxygen that causes pitting of the boiler drum. 3.) Increases plant efficiency using exhaust steam to heat the feedwater in the D.A. Tank. (every 10f rise in feedwater temperature, there is a 1% fuel savings). 4.) It is a reservoir for available feedwater. 5.) The D.A. Tank is located (10ft) above the feedwater pumps on the suction side, providing pump head (positive pressure) caused by gravity. 6.) Condensate return storage tank. 7.) Reduces thermal shock to the Boiler. 8.) It is easier to remove scale-forming salts in the D.A Tank then in the Boiler.
When we design the systems, we do calculate out exactly what these pumps will need to run properly and without cavitation. What we cannot plan for is any external factors that might lead to situations that cause the cavitation. Anytime operating conditions change (such as PRVs being stuck open letting in too much pressure), even with proper calculations, cavitation can occur. Hopefully that clears things up and thanks for watching!
As it is said in the video, cavitation can happen when the pump is not getting enough supply. This could be due to many different things which could include proper pipe design to the pump. Cavitation can also happy with any pump not only feed water pumps so it is something to look out for. ruclips.net/video/0dd6AlyOnfc/видео.html Here is a really good video that visually shows cavitation and how it can be created. Hopefully that helps. Thanks for watching!
We do not have a specific video on vacuum pumps. Is there something specific that you would like to know? We might be able to make a video about it. Thanks for watching!
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I`m an old navy BT. I`m a pipe fitter/welder these days. I teach a steam class at an apprenticeship school. Your youtube videos are priceless for visual aids. Thank you so much and please keep up the good work guys, Bravo Zulu!
Glad we can be a resource. Thank you for the kind words and if there is anything we can help with please let us know.
Hi, could you explain how is the procedure to heat the make up water, when de boiler is run for the fist time, and the water is cold?
thanks
My DA tank is banging after the cold water feed valve shuts. The pressure goes from 5 psi to 3 psi and seems like it goes into a vacuum. It’s a Bryan tray type. My other DA gets its feed water from the surge tank so the water is preheated so there is no shock.
How do I get rid of the banging
Overall, a good video. A couple of nits need picking, however.
1. The deaerator (DA) is a direct contact heat exchanger where steam and liquid come in direct contact. This raises the temperature of the condensate sufficiently to allow non-condensable gases to be liberated. As the DA supply steam is regulated to maintain the shell above atmospheric pressure, the gases flow naturally through vents into the atmosphere along with a small amount of steam.
2. Cavitation is the result of the pressure at the "eye" of the pump impeller falling below the saturation pressure for the liquid being pumped. This creates steam bubbles that travel with the liquid toward the discharge (high pressure end) of the pump. When the pressure exceeds the saturation pressure, the bubbles collapse. It is the collapsing bubbles that cause the sound like "pumping rocks." Think of the sound of clapping your hands together. The walls of the bubbles (incompressible liquid) coming rapidly together, makes the noise. At the same time, these little "shock waves" impinge upon the impeller and slowly "jack hammer" the material away.
This is what Net Positive Suction Head (NPSH) is all about and why the DA is normally installed at an elevation significantly higher than the feed pump suction. The static head of liquid in the DA and the low-low DA level switch protect the pumps from this damaging phenomenon.
Appreciate your response and while everything you say is technically correct we try not to get too deep in the weeds with these videos. If it gets too technical then we tend to lose our audience. Giving them just enough information so that they know why things happen but not so much that we lose their interest is a balancing act that we have to do on all of these videos. Our Boiler University gets into the weeds, real deep. That is where we take the time to explain, in detail, all of the points you make plus much more. Hopefully that makes sense.
Again, really appreciate your feedback and you continuing to watch our videos.
Thank you guys! This video series is my refresher before I proceed to work on a process.
What is the minimum size boiler you would use a deaerator on? At smaller sizes i would imagine a Spirovent or Pot Feeder of Oxygen Scavenger would make more economic sense? I haven't seen deaerators on small residential or small apartment building applications but that may be my limited exposure.
How is it made?
Pls help especially to the Budget for my study of Projectile...
How do you abstract the oxygen from the water?
by "stripping " go back to 1:29 he explains it
Is it still considered water without oxygen?
The Constructions of Deaerators are a few types! tray construction is known well! But, I would like to apply Packing materials instead of trays.....
Thank you for the detailed info!! I have a quick question...I understand that the oxygen will be removed from the feed water before it goes to the boiler. so can water stay in liquid state if 'O’ is removed from H2O? Please help me understand. Thanks!
It’s removes the dissolved oxygen
Thanks guys, great help.
The deaerator....#1 most overlooked piece of equipment for boiler feedwater issues
100% agree! Realizing your boiler room is a system rather than just the boiler is a really good step in understanding problems you could be having. Thanks for watching and commenting!
How much does that deaerator cost?
Nice video to refresh my experiences...thanks Sir
Always welcome and thanks for watching.
Thanks guys.... great job...
I was asked on my L.A. Steam License exam to name five purposes of a D.A tank and everything that I have read, gone to classes on they only mention three, which you guys went over.
1. Preheats the boiler feed water. 2. Removes oxygen. 3. Act as a storage tank. What would be the other two purposes?
Two other purposes of the DA could be that it removes carbon dioxide and recovers flash steam returning with condensate. In a vented receiver this would be lost. Hopefully that makes sense! Thanks for watching and commenting!
Pre heat cond return, pre heat make up water, remove noncondensables from make up water, remove noncondensables from cond return, and store feedwater. Theres 5 lol ;) get technical
Haha thank you. I passed, this is what they wanted to hear incase anyone else needed some help!
1.) It is a preheater for Boiler feedwater
2.) Removes Oxygen that causes pitting of the boiler drum.
3.) Increases plant efficiency using exhaust steam to heat the feedwater in the D.A. Tank. (every 10f rise in feedwater temperature, there is a 1% fuel savings).
4.) It is a reservoir for available feedwater.
5.) The D.A. Tank is located (10ft) above the feedwater pumps on the suction side, providing pump head (positive pressure) caused by gravity.
6.) Condensate return storage tank.
7.) Reduces thermal shock to the Boiler.
8.) It is easier to remove scale-forming salts in the D.A Tank then in the Boiler.
what an informative video 😮❤❤
Glad it was helpful!
Keep the videos coming, boys.
so you should compute NPSH correctly to avoid cavitation.
When we design the systems, we do calculate out exactly what these pumps will need to run properly and without cavitation. What we cannot plan for is any external factors that might lead to situations that cause the cavitation. Anytime operating conditions change (such as PRVs being stuck open letting in too much pressure), even with proper calculations, cavitation can occur. Hopefully that clears things up and thanks for watching!
Also you guys spoke about cavitation .... this can appear when??. Booster pumps??? Maybe ???. With not a proper pipe design also?
As it is said in the video, cavitation can happen when the pump is not getting enough supply. This could be due to many different things which could include proper pipe design to the pump. Cavitation can also happy with any pump not only feed water pumps so it is something to look out for. ruclips.net/video/0dd6AlyOnfc/видео.html Here is a really good video that visually shows cavitation and how it can be created. Hopefully that helps. Thanks for watching!
Thamks❤
Thanks for watching!
Great video as always, do you have one on vacuum pumps, I think that's what they are called , used to pull condensate back to boiler in buildings !
We do not have a specific video on vacuum pumps. Is there something specific that you would like to know? We might be able to make a video about it. Thanks for watching!
@@wareboilers Hey Guys hope all is well - a video on vacuum systems, how they operate would be great 👍
Nice