Grease burning boilers

[bhabte12]

Guys,

I have just been an observer in this forum for a while now. But now, i have got a question.
We are trying to burn grease,(a process bi-product) in one of our water tube boilers. Its D frame Babcock Wilcox, I am not sure of the HP but about 50, operates at 340F and 128PSIG. The problem is we have impurity build up in the boiler creating scale and insulating the water from the fire. After running the grease for a while, we see increase in stack temp, implying reduction in efficiency.
- Is there anyone with the same problem out there?
- Are there any cleaning methods beside centrifugal cleaners?
- Could you also use some kind of dispersion material injected with the grease in time interval to remove the scale?
Any suggestion is appreciated!

 

[rmw]

I have seen quite a number of fuels burned in boilers, but grease burners is a first for me.

Is this grease like lubricating grease or cooking grease? If lubricating grease what type of soaps are in it? If it is lubricating grease, I think the soaps are your problem.

Please describe "centrifugal cleaners". It is an uncommon term. Are you referring to rotary steam soot blowers?

rmw

 

[bhabte12]

The Grease i am talking about is the one of our bi-product from the process. I am in the pork industry. one of the bi product is called the choice white grease. I think the beef industry has an equivalent called tallow. At any rate, our choice white is not used for lubrication and only used as fuel. Specially when the natural gas prices is high the fuel is changed in to choice white. The centrifugal cleaners (polishers) are grease cleaners that use the centrifugal forces to remove solid particles. the higher the force(the faster the rotation), the smaller the particles you can remove.

Anyway, the particles that are not removed would scale up in the pipes of the water tube boilers. (i think they calle this process fouling)
I don't know the tolerance for particles in the boiler,
I think we have insolubles exceding 250ppm in the choice white (after the current clean up)

that is all the details i can think of right now!!

Thanks for the feed back guys!

 

[vpl]

bhabte12

I've been mulling this over for a couple days. While I think what you're getting is a carbon buildup from excess animal material in the grease, I'm not the best person to ask in regard to how to clean it off.

I'd suggest that you repost this question in the Chemical Process Engineering forum (forum 798). I think you might get a better answer there.

If you do decide to cross-post over there, be sure to leave a note here, telling people to go to that thread.

It's an interesting question.

Patricia Lougheed

Please see FAQ731-376 for tips on how to make the best use of the Eng-Tips Forums.

 

[rzrbk]

Is the build-up on the tubes in the radiant or convection section?

Also, how is the grease being burned? (injected thru an atomizing tip burner? with/without steam?)