Shell boilers are those in which heat transfer surfaces are contained inside a steel shell.They are also known as fire tube or smoke tube boilers as the products of combustion pass through the boiler tubes and transfer heat to the surrounding boiler water.They allow for greater area of heat transfer along with allowing boiler water to be heated to a point where the heat from the furnace will be the highest. The combustion gases should be cooled to at least 420°C for plain steel boilers and 470°C for alloy steel boilers before they pass through the reversal chamber. Temperatures in excess can cause overheating and breaking of the tube end plates.
Shellmax by Thermax is among the best in this category in the market. It comes with a packaged, three-pass smoke tube, with a fully wet back boiler. There are two series provided under Shellmax-

(i)SMDL: For burning light oils & gas

(ii)SMDH: For burning heavy oils.

The boiler can also be customised to a completely skid mounted unit based on customer demand. These boilers are perfect for burning waste gases like biogas, corex from the steel manufacturing process, and liquid fuels if they are fitted with a special burner.

Here are the specifications on the operating range:

•Capacities : In the range of 1 TPH to 25 TPH

•Pressure : In the range of 10.54 to 17.54 Kg/cm2 (g)

•Temperature : Up to 75ºC

•Firing fuels : LDO, FO, LSHS & natural gas

•Efficiency : Overall efficiency of 88 % (+/-2%) on NCV

The product features of Shellmax include:

1.Multi-fuel option - light oils/heavy oils/gases

2.High efficiency of about 88% to 92% and high dryness fraction steam to increase usable heat

3.Fitted with mono-block/ dual block/steam atomised burner made from world-renowned technology from Finland

4.Large water holding capacity and optional 3-element control system for monitoring the water level, steam flow, and feed water flow closely. Unexpected large steam demands like a pit-winding engine being started can easily be tolerated because of the reduction in boiler pressure which releases copious amounts of flash steam from the boiler water which is at saturation temperature. The water capacity also means that the rate of change in the water level is relatively slow.

5.Corrugated furnaces for heaters above 4 TPH capacity

6.Optional PLC based control panels that can be connected to SCADA or DCS systems

7.The low-level alarm was simply a float that descended with the water level, and opened a port to a steam whistle when a pre-determined level was reached.

8. The surface area of water is large in relation to the steaming rate resulting in a low rate at which steam is released from the surface.

To learn more about Shellmax, visit https://www.thermaxglobal.com/. Thermax brings an experience of over four decades in providing the finest heating equipment for many industries.