Can Secondary Chamber be to Hot?

[ozzie88]

I built my own Gas. boiler , after alot reserch did all sizeing myself, and after 4 test runs think I got air adjust good now. I can adjust air in both chambers top and bottom of first chamber and secondary, and get a yellow to orange to purpel to hot blue flame in secondary, and it is HOT! I have a 3/8 steel rod that the tip is in second chamber [use it to slide panel] it is white hot, the 2 1/2 inch fire brick are glowing red hot, have to be 2000 degrees?
Is there a thing as to hot?

 

[PassionForFire&Water]

The steel should not turn any color if it is water cooled, this is the concept behind a boiler.
Maybe you should increase your water flow
Also, maybe to much O2. Do you have means to test for O2 in the flue gasses.
Should be max around 10 to 12%. The lower the better, =higher efficiency, but more difficult to keep the combustion going under all circumstances
Also check for CO if you can, will give you an idea on how clean it's burning.
1000 ppm CO is not so clean.
250 ppm CO and lower is good.
below 50ppm CO is excellent.
Make sure you have some safety accessories on this boiler !!
pressure safety valve
Temperature safety valve
Boiler feed valve with back flow preventer

 

[ozzie88]

Thanks for info, I will plane on haveing a friend check the levals that good idea. I do have saftey controls, a honey well controls water temp. on and off and also the ele. cold air vent flap. Have 30 lb. preasure vale, and over heat switch that turns cir. pump on at 180 & off at 165, water temp seems to be ok? while running the boiler tank is 15 degrees warmer than the storage, I thought this sounded ok, when it shuts off the over heat switch will kick on and off for couple hours till the firebrick cools, I just dont want to ruin the brick being so hot.

 

[jebatty]

I have a 3/8 steel rod that the tip is in second chamber [use it to slide panel] it is white hot, the 2 1/2 inch fire brick are glowing red hot, have to be 2000 degrees? Is there a thing as to hot?

If this rod is in the gasification chamber and close to where the gasification actually is occurring, then this is close to what you might expect. For a temperature guide based on the color of the steel, see (broken link removed to http://www.uddeholm.com/files/Temperatureuide.pdf). The colors of flame you are seeing are typical. In fact, with my Tarm, during mid-high burn I see no flame color at all, which to me indicates that the combustibles are probably entirely CO and H.

And I think it can be too hot, but that relates to the materials you are using in and around the gasification chamber. I don't know what the specs are for your fire brick or other materials. I don't think all fire brick is equal in this regard. I doubt that steel will last very long in this environment. My Tarm has an air control located away from the gasification chamber, and there is no steel in close proximity to the gasification "flame" that is not highly protected by some type of ceramic or other insulation or having water on the other side.

 

[steam man]

First of all, things can be too hot. You may be overfiring. Too much air/fuel for the boiler to handle. The stack temp would be a good indication of too much heat along with how much heat the boiler removes through the water. What is your stack temp?

Mike

 

[ozzie88]

Hello, Thanks again for the help, My stack temp. when running hot is between 330 to 440, most of time it around 300, The choker or baffel I made that is in the center of second chamber to swirel the air and hold some back for better combustion is made of 5/8 Cordienite which is rated at 2730 F. max. and firebrick is 2600 degree F. I e-mailed the place I bought them see what they say. I have some 1/2 inch peep holes with caps I can look threw and see chamber, what hits the water jacket is just the heat, the fire is all in and surounded with firebrick and the cordienite panel. steel is 3/16 thic on water jackets.
I will take photos of fire next time I fire it and ahow them. Chuck