Steam Heating Element Immersion Electrical Heater
Description of fin tube steam heaters:
In applications where tubular heaters are exposed to forced
convection, placing fins around tubular heaters increases their
surface area and thus improves their heat transferring capacity.
Finned tubular heaters, compared to regular tubular heaters, run at
lower surface temperatures for the same watt densities when placed
in identical air streams. Graph1 compares watt density, outlet air
temperature, and the speed of air flow for regular and finned
tubular heatersrespectively. Despite their advantages, finned
tubular heaters are not recommended for applications where outlet
air temperatures exceed 600°F.
The physical characteristics of a finned tubular heater play a
major role in the effectiveness of its heat transfer. The table
below specifies the outside diameter of fins, their thickness, the
spacing between consecutive fins, as well as the element sheath and
fin material.
Application of fin tube steam heaters:
Dryers
Recirculation ovens
Fan-forced heaters
Heat treating and annealing
Construction of fin tube steam heaters:
The sheath material of a fin tube steam heater and its watt density
are critical factors that affect its durability. The standard
finned tubular heaters are made of steel sheath and steel fins
(750°F maximum surface temperature) since steel is very efficient
in heat transfer. Finned tubular heaters have a plain-surface
finish. For corrosive environments or high-temperature applications
(above 750°F), finned tubular heaters can be made with stainless
steel sheath and stainless steel fins.
Watt densities of fin tube steam heaters:
Safe watt densities that keep surface temperatures below allowable
limits depend on the speed of the incoming air and its outlet
temperature.
Physical characteristics of finned tube heating element:
The outside diameter of fins, their thickness, the spacing between
consecutive fins, and the element sheath and fin material all play
a major role in the effectiveness of heat transfer.
| Tube diam. | Fin thickness | Fins per inch | Fin width | Total in² per linear inch* | Max. sheath length* | Outside diam. of fins |
| 0.216" | 0.020" | 5 | 0.375" | 8.30" | 240" | 1.01" |
| 0.315" | 5 | 9.20" | 1.07" |
| 0.375" | 5 | 10.10" | 1.13" |
| 0.430" | 5 | 10.83" | 1.18" |
| 0.475" | 5 | 11.60" | 1.23" |
| *Dimensions are subject to change |
Optional features of fin tube steam heaters:
- Rustproof coating
- Stainless steel fins and tubular sheath material
- Nickel plating
- Special mounting accessories
- Various shape
Mounting attachments of fin tube steam heaters:
Threaded fittings, if required, are the standard mounting
attachments supplied with finned tubular heaters. These fittings
are brazed or crimped onto the heaters. For special applications,
finned tubular heaters can be made with mounting brackets that have
special designs.
