As in the western movies, a dedicated worker, diligently chunking coal and wood into a firebox, would burn a fire for steam locomotive boilers. Nowadays, that same job of making water boil from a fire is done with burners like the ones sold by Power Flame, the burners most typically used by Hydra Portable Steam Boilers. Conceptually, a boiler is no different than a pot of spaghetti water on the stove. Get it hot, and it boils with steam.
For the industrial boilers we sell, electrical heat is not very often economic. Gas is on the order of a quarter the cost of electricity. Diesel is less than electricity in most cases, but it is convenient for portable boilers. It's easier to bring an oil tank than to find enough power to run a hydra portable steam boiler.
Practical choices include natural gas or diesel (otherwise known as Number Two Oil). All modern burners atomize the fuel, and some of their measurements are the size of the atomized droplets measured.
The burner mixes the fine mist of oil or gas with the atmosphere. This is important for two reasons. One is pollution. Avoid by fully burning everything. The second is efficiency. Burning all the fuel is better than burning part of it.
Inside, insulated burners have grown in their availability and now come in numerous makes, models, and types. Some users want fully modulating, and others use step-down models. It depends on the customer budget and uses as to which is better.
The parts of the burner include the nozzle or atomizer, the fuel supply, the air supply, the blower, and the electronics; the electronics come in different types, with some modulating more than others. The exclusive design of each firing head allows for the most efficient and stable combustion in any surrounding condition, plus no assembly, wiring, or fire-testing is required as manufacturers took all the hard work from the process and made everything simpler for buyers to open and use immediately. Products are UL certified.
The Hydra Portable Steam Boiler 60 BHP contains a Power Flame Burner.
From their website: "Power Flame's forced draft gas burners are designed to fire natural, LP and various waste gases. Exclusive firing head designs provide optimum efficiency and stable combustion under either negative or positive chamber conditions. Shipped completely assembled, wired and factory fire-tested. These packaged combustion systems are listed by Underwriters Laboratories, Inc. (UL)".