Burner retrofit for scotch box

Smith19

Hi all,

I've got three Hurst LPE steam boilers that were installed in 1995-1997. They have Gordon Piatt model R gas burners which run nicely, however finding parts can be a pain. They aren't too efficient either. The building runs with a DA pneumatic and has a Quincy compressor. Im wondering this: Can we do a burner retrofit to cut down on our stack temps and carbon footprint? are there low NOX burners available for this boiler? Does a low NOX burner work well with a boiler like this?



I'm also wondering about our stack and flue set up. It's complex and redundant, and takes a longer purge time to run air through it. on cold windy days, we get some back draft, which is obviously not good. Should this be taken care of before/along with the burner retrofit?



just like to mention - whom ever installed this overlooked hartford loops - so there's that



attached are photos



cheers

Dave in QCA

Powerflame

It appears that the company that owns Hurst, http://www.federalcorp.com/ May also own Powerflame Burners. At any rate, I would go back to Hurst Boiler and see what their advice is. If parts are the only issue, I would be that you will be able to service that burner for LONG time. All of the parts should pretty much be off the shelf, i.e. honeywell gas valves, fire eye controlls, and so forth.



I am going to assume that the boiler has turbulators in the flue tubes. If not, you should add them. That, and lowering the firing rate is the only way to decrease the stack temperature. Low stack temperature is not the only indicator of efficiency of course. Do you run a combustion analyzer on that boiler? What readings do you get?

Mike Kusiak_2

Gordon Piatt

The Gordon Piatts are a  good burner, and I would doubt they are the cause of your problem if they are set up properly. As Dave mentioned, most of the parts are standard off the shelf items and the other proprietary one are still available.



I am running three 80 Hp Scotch Marine boilers with dual fuel Gordon Piatt burners, and they have been all working at 85+% combustion efficiency for more than 10 years. We have no plans on replacing them any time soon.



High stack temps are more a function of the boiler itself and its heat transfer characteristics, rather than the burner unless you are overfiring.

Smith19

pneumatics

The real cause for the issues we face is the DA pneumatic system we've got.  It leaks constantly, which generates false calls for heat.  The compressor cannot generate dry air, due to the fact that the refrigerated air dryer is busted up.  (That is a separate issue we are currently working on).  You may wonder, why not just work on the pneumatics instead of the GOPEG burners?  Or even upgrade to DDC?  The reason is cost.  The controls in this building are an infinite world of expense, and I understand that it will have to be dealt with at some point.  Until then, we just need a few lower cost ways to upgrade the boilers. 



Cheers

SWEI

controls

DDC is almost certainly in your future, but if you can find a way to keep what you have working for a few years, by all means do so.  Take the next couple of years to educate yourself on everything you can about DDC, especially about the business practices and "plays well with others" characteristics of both your local installers and the manufacturers they represent.

Dave in QCA

pneumatic control OK

I have been responsible for boilers and control systems in buildings, one complex had probably about 1000 Johnson control devices. If found the system to be reliable and very functional. Of course, like everything, it does require maintenance. Air dryers are not all that expensive. Check on ebay for a used one. They normally will run for 30 years or more no more maintenance than cleaning the dust off the condenser. Rubber diaphrams for valve operators do fail, but are easy to replace.



If it were my system, I would very accurately tune the existing burner and put my money into getting the controls working. Broken controls equal wasted heat. Its pretty much like the old systems where the heat ran full blast and the control system consisted of opening the windows to cool the space down.



What make of system do you have?

Smith19

pneumatics cont.

Funny you should mention the open windows. In this 1952 building, that's all we've got to cool the place down. At times, we loose pneumatic, and the heat exchangers on the air handlers read 200+ degrees F. I might cut the fans if the rooms get above 93 degrees, (even with open windows) but then all the heat and damage goes to the heat exchanger. These air handlers were built by a company called Drum, and I don't think it exists anymore. The heat exchangers are not copper coils, they're like cast iron radiators.



The system has a quincy duplex compressor that has been modified over the years. It has a Hanksion air dryer from 2010. The thermostats are all JC, and the actuators range from JC to Honeywell to Siemens. The mediums in the air lines are copper, (1952) plastic irrigation tubing (1997), and light rubber tubing to the thermostats. (2011). The reason we can not tune the system is because we would need to get behind walls, and then we run into disturbed and loose asbestos in the cinderblocks. Remember, the building is 1952.