Steam Generator

Hi,

5 years ago, I worked @ a factory where they did maintenance of steam generators. And selling these baby's.

They had 2 elektriciens, old ones.

Now, they want some extra force for the elektrical part.

My question: Steam Generators running on PLC's HMI systems, SCADA systems etc..., I never seen a steam generator with a PLC.

Does anyone know more, I mean, information about steam generators running on PLCs

Your work is done.

Do a search for "steam generator water level control"

http://www.ornl.gov/~webworks/cppr/y2001/rpt/111784.pdf
Some ligth reading

You don't have to re-invent the wheel.
http://www.dicsintertrade.com/frames/SGWLCS.htm
This is a lot fancier than the one on the sub.

A steam generator water level controller (sgwlc) is tricky. You need to balance the mass of the water going in with the mass of the steam going out. The water level itself is often a poor indicator because as the steam demand increase, the pressure inside the SG decreases. This causes more bubbles to form that make it look at first glance that the water level is increasing, which it is, but the mass is actually decreasing because much of the increase in water level is caused by the bubbles.

Be careful. There is big difference between building and controlling a SG. This is a job for real good mechanical/control engineer. SGWLC is a tricky process that shouldn't be taken lightly. You had better be able to model a SG, know hydraulics and theromodynamics, diffential equations etc.

Its been 25+ years since I have worked with one of these. I was just a glorified operator then.

There are numerous manufacturers of Steam Generators across the world.
We use a few; (I am in the Pharma world)

Finn Aqua Pure Steam Generators
Getinge AutoClaves and Steam Processors
Lytzen Inc,

Combo,

Steam generator (SG) is general term use to refer to a number of industrial equipments. What king of SG are you talking about? For instance: industrial auto-clave?, fire tube boiler?, water tube boiler? ...



In the case of industrial auto-claves or fire tube boilers where steam is produce solely as a source of heat (not to generate electricity) PLCs are currently used. The major control loops are:



1) Drum level control (of 1 element maximum 2).

2) Combustion control



Minor loops (trim):



3) Blow down control (purge)

4) Oxygen trim (flue gas)



The safety and interlock logic is called "burner management control" is by far the most important part of the control. Nowadays with the increasingly use of standards such as IEC61508 and IEC61511 (safety integrity level) simple PLCs don't longer offer enough safety integrity level so some people re-enforce their design by duplicating every thing (redundancy) some times triple redundancy (read more about the subject in the following standard NFPA 85.xx)... far too complicate for a little boiler. I recommend instead to buy a pre-approved burner management controller (BMS) like Allen-Bradley Fire-eye automaton. This controller are quite suitable for controlling the start-up and shutdown of little steam generator, besides they avoid the hassle of over-designing and writing PLC code that later MUST BE TESTED AND VALIDATED for the local authorities (here is the GAS Authority) ... another thing is that once validated the PLC code should be protected against tampering (if a change is required (even a minor one) the testing and validation will have to be carried out again.

I hope this help ... should you require further details about the control loops and techniques used please don't hesitate in contact me.

BEWARE: The control of boilers and furnaces is a highly regulated industry. Professional liability is high.

Cheers,
LJAM

Here in the states there are several agencies and a ton of regulations covering this.

I would not attempt anything, do to the regulations, and potential liabilities.

I suspect that things are much more relaxed where you are.

Good luck if you attempt anything, and remember Safety First, Safety Second, etc

regards.....casey

Here in canada (at least ontario) anything reagrding pressureised staem is regulated by the TSSA.. I wired a boiler for a plant and was asked to get them some spare parts..(Honeywell controllers) becouse the manufacture of the boiler was hosing them for spares..I searched and called and called and NO ONE would sell them to an electritian becouse i was not TSSA certified..Even tho i was not even installing them (Thats the stationary engineers job).. I got into a little ****ing match with one of the sales reps becouse he said i had to be a certified gas fitter to install the modules..He didnt know what to say when i told him that according to the OHSA you had to have a electrical licence becouse 110volt power was involved..Anyway..it bugged me becouse i had to go back to a customer and tell him i couldnt get it..I lost a sale..and so did all the canadian suppliers becouse he ended up bying them from a US company...

To get back on topic i will say i would not change/alter or develop any control system for a pressure boiler..I say that from a liabilty issue..I could do it and it would be safe but IF anything happened..we all know where the finger would point...

Boilers and process steam generators I've seen use stand alone PID controllers like the Siemens (formerly Moore) 353 series because of ease of function block programming the PID. The flame safeguard is the only digital, besides an alarm or two. amd flame safeguard is a separate (from process control) dedicated, agency approved device.

Hello Friend
My companie make lot of project with Steam Generator, who work with
Natural Gas, Biomass,Fuel, Wood, controled by PLC and SCADA Tecnologie
If you want I can send you Photos by email about this theme.
Email me if you want the photos.
[email protected]
Regards
Jose