Direct Superheated Steam Injection
Direct Superheated Steam Injection
(OP)
We want to heat between 3~15L/s of water from 10-50°C using direct steam injection of 225°C 14bar.g superheated steam. This is from a site loop off the back of a power plant turbine.
My question is what issues if any arise from the steam being superheated when it is injected rather than saturated? The concept is just to control the rate of steam from through a mixing tee to achieve instantaneous heating of the water. Is there anything to worry about (cavitation, thermal shock)
Your thoughts and ideas are appreciated.
Thanks
My question is what issues if any arise from the steam being superheated when it is injected rather than saturated? The concept is just to control the rate of steam from through a mixing tee to achieve instantaneous heating of the water. Is there anything to worry about (cavitation, thermal shock)
Your thoughts and ideas are appreciated.
Thanks





RE: Direct Superheated Steam Injection
I always thought it was never a good idea to hit liquid water with live pressurized steam. My biggest concern would be death.
RE: Direct Superheated Steam Injection
I haven't any experience with them but I've seen more than one advertised direct steam injection to give hot water. I don't think superheated steam is an issue, the real issue is when the steam collapses as it condenses.
Hopefully someone else on the site will have some direct experience.
RE: Direct Superheated Steam Injection
The merits of using the super-heated site loop is that its free to us and unlike indirect heating through a desuperheater+condensing HX we dont have any condensate taking heat out of the system . Its consumed in the heating process (more efficient)
RE: Direct Superheated Steam Injection
We had on one job to put in a tempered water system to supply safety showers. Our options were an industrial hot water tank with a blend valve to give the desired temperature, in-line electrical heating or direct steam injection. No one on the client's side (or us for that matter) really like the idea of direct injection steam feeding safety showers but they were supposed to have the appropriate ratings (can't remember just what they were, ANSI?). We ended up going with the hot water tank and blend valve skid. I've also seen ads for direct steam injection for wash down stations where you want hot water.
Get some literature, talk to the reps and get the names of some users to talk to.
RE: Direct Superheated Steam Injection
rmw
RE: Direct Superheated Steam Injection
RE: Direct Superheated Steam Injection
I have seen this in food process also, it how they make apple sauce. There is an even longer list than Mike gave us of people that build these systems. I like Pick.
= = = = = = = = = = = = = = = = = = = =
Plymouth Tube
RE: Direct Superheated Steam Injection
Everyone is quite correct that you don't just want to inject steam into a water line through a simple tee or nozzle.
All the different devices have been engineered to avoid the water hammer issue.
I suggest putting together a simple material balance for the system and sending it to one of the vendors suggested.
Good luck.
RE: Direct Superheated Steam Injection
www.pickheaters.com
However, I caution you to consider both the noise and the vibration that are generated with this kind of heating method.
These are not minor considerations !
RE: Direct Superheated Steam Injection
Direct Steam injection is well established for heating a variety of fluids. However, it does need to be done in a controlled manner. The amount of energy being transferred can be quite high.
This question regarding superheat is important as it can have some impact on performance of the injection device. Not all devices handle it equally well. Make sure you communicate the amount of superheat you expect with the vendor.
There is a lot of good technical information available at:
http://www.pro-sonix.com/engineersToolbox.asp#bull...