Retrofitting of Bagaase Fired Boiler to Coal

Pulverized coal is usually burned in a fluidized bed, i.e. air is passed through a chamber containing the coal from the bottom. This enhances burning of the coal which is replenished through an inlet in the bottom of the combustion chamber. There is no "grate" involved in this process. As pulverized coal has the physical consistency of coarse sand, a grate would have to have micro-fine holes to precent the fines from falling through.

A bigger problem might be the temperature achieved by burning coal which can be high enough to melt your ash and produce a glassy slag which will "gum up the works." People who burn coal in a continuous process must obtain an analysis of the coal they buy to determine if it will produce "fly ash" or molten slag. The equipment for handling the ash must be appropriate to the kind of ash produced.

What do you know about the coal you will be burning? What is its ash fusion temperature? At what temperature will your burner operate? Are you equipped to handle fly ash? fused ash? What are your disposal plans?

Dear Mr. Gene Hayes Thank you for your comments. I will get the information you have asked for from the Client. I will contact you again very soon.

It looks like Mr. dhayanandhan has a good handle on your situation; my coal experience is with power plants, and may not translate well to your situation.

Good Luck.

Dear Mr. Muhammad Farooq,

YES. IT IS POSSIBLE TO USE CRUSHED COAL in a Baggasse Fired Boiler, provided suitable Design Factors are considered and equipments are installed.

Travelling Grate is a MUST. Other Factor to be considered is - For a given capacity of Boiler with BAGGASSE only as Fuel, if coal is used in that - the capacity will not be the same as that for baggase firing. Hence if coal is to be used for 100% capacity HEATING SURFACE is to suitably provided.

From which place/country you are working.? I am from INDIA, there are several Sugar Factories in INDIA, using BAGGASSE during SEASON and COAL in the OFF-SEASON. At times coal and Baggasse also mixed.

The company where I am working now has 2 SUGAR FACTORIES of 5000 TCD Capacity and we generate 30 MW in each factory and export 20 MW from each Factory. In the off season Coal only used, and export about 26 MW, balance is our IN-HOUSE and AUXILIARY LOAD.

DHAYANANDHAN.S

Give us some more info on your boiler. Type of grate for one. No problem using coal. If you have a superheater the steam temp will be lower. Be a good project. Not sure where the fluidized bed fits in. Don't use that with bagasse.

Dear Mr. Dhayanandhan Much pleased to have a positive answer. Thanks. I am from Pakistan. One of our client i.e sugar industry want to install additional equipment to use coal for firing the bagaase fired boiler with coal in the off season. They thought pulverised coal will be better. Since their boiler is of fixed grate type, I am of the view that crushed coal could be economical. From your reply, I am now sure to have a good proposal. Please let me know what information you will need me to send to your company regarding the existing boiler. I will need your contacts i.e. telephone and email. Best regards.

Dear Mr. Muhammad Farooq,

Thank you for your posting.

Pl. provide the full and complete Boiler Details, Sugar Plant Crushing Capacity, Baggasse % Cane, BAGGASSE ANALYSIS details, Chimney Height, Is there any Blow-Down Water Heat Recovery? Plant Electrical Load, Auxiliary Power Consumption, Sub-Station Details.

The decision to be taken in totality and not on segmental working - then only we can achieve and get best results.

Pl. give brief details in this forum, so that other CR 4 Members also can see yur reply and offer suggestions.

The data which I am asking is will be in large volume, and you can send through personal messaging system available in CR4.

DHAYANANDHAN.S

Why not just direct your client to CR4 so that the forum can communicate directly with the boiler operator?

That will take much less time and reduce the likely hood of misinterpretation of what is said here by you, to the operator of the boiler?

And we won't charge him for our services.