adding amines in a steam system

[deadude]

WE have a 125# steam boiler system and the chemical guy is adding neutralizing amines to the feed tank with a preheater. Is this the proper place or should it be after the boiler after steam is produced?

 

[ash9144]

Boiler feed water is where you want it. That protects your boiler not just the piping.

 

[TBP]

Amines are typically used to protect condensate lines. If they get fed into a vented tank - like a DA, you'll lose quite a bit out of the vent. You should normally feed them into the steam header with an injection quill, but just remember that you'll need a pump with enough discharge head to feed against the 125 PSIG instead of against the low pressure in the feed tank.

 

[cjw81]

TBP is on the money - amines when put into a boiler are the only chemicals that leave the boiler with the steam. They are specifically designed to do that and when they go around the system they change the PH back to a neutral (you are hoping for a 7.0 PH (not likely but close is good enough. The old amines 30 years ago were reported to be carcinogens, so be careful to check the chemicals you are using for safety. This could get ugly fast when you are also using process steam for humidification.

 

[rb249]

Amines should be put into the feedwater line , or feedwater (condensate preheater)tank prior to boiler injection. An excellent amine is morpholine. It has a 13pH so PPE is definitely needed when handling. The amine being injected at the feedwater will protect the boiler, components and piping, as well as any unit heaters, exchangers or process components. Consult NAPE for any concerns you may have regarding process and treatment. This organization has many qualified members working in various industries/facilities comncerning steam generation. As in another reply, injecting into a steam header requires expensive, maintenance nightmare equipment to overcome the internal pressures. Into the feedwater is more beneficial and less costly.

 

[ashaari]

In my plant, we inject the amines in the boiler feed water line as others have mentioned. To be exact, the amines are injected in the piping downstream of deaerator and upstream of boiler feed water pumps. We inject it by using chemical metering pump.

 

[littletoes]

On another note, aren't there "three" types of Amines? One that works on piping systems "close" to the boiler, another that works on the piping systems "far" from the boiler, and now a third, which is a combination of the first two, hoping to work on systems that have long runs of pipe, and to also be able to coat the piping that is close to the boiler.

By coating the inside of the piping/coils, etc. it protects the piping from corrosion from such as carbonic acid, as an example.

 

[rmw]

I don't trust chemical salesmen as far as I can throw them. He may be adding it to the feed tank knowing that you will loose some in the deaerator vent and hence, he will have to sell you more. If he is any good at all, he should have known better.

Also, is your BFW system modulating or on-off? That may make a difference as to where you pick to add the amines.

rmw