Chromalox Big Red Book

Technical

Technical Information Allowable Watt Density & Heater Selection - Air Heating

Graph G-154-1 — Fintube ® & Tubular Heaters Sheath Temperatures with 16 FPS Distributed Air Velocity

Graph G-151-1 — Fintube ® & Tubular Heaters Sheath Temperatures with 1 FPS Distributed Air Velocity

40 35 30 25 20 15 10 5

40 35 30 25 20 15 10 5

Limit for Finned Tubular for Normal Life Expectancy

Limit for Finned Tubular for Normal Life Expectancy

1 2 0 0 ° F

1 4 0 0 ° F

1 4 0 0 ° F

2 0 0 ° F 4 0 0 ° F 6 0 0 ° F 7 0 0 ° F 8 0 0 ° F 1 0 0 0 ° F

1 2 0 0 ° F

4 0 0 ° F 2 0 0 ° F 6 0 0 ° F 8 0 0 ° F 9 1 0 ° F 1 0 0 0 ° F 80 70 60 50 40 30 20 10 0 Watt Density in W/In 2 of Effective Length

80 70 60 50 40 30 20 10 0 Watt Density in W/In 2 of Effective Length

Tubular Units

Tubular Units

Finned Tubular Units

Finned Tubular Units

0

200

400

600

800 1000 1200 1400

0

200

400

600

800 1000 1200 1400

Outlet Air Temperature (°F)

Outlet Air Temperature (°F)

Graph G-152-1 — Fintube ® & Tubular Heaters Sheath Temperatures with 4 FPS Distributed Air Velocity

Graph G-155-1 — Fintube ® & Tubular Heaters Sheath Temperatures with 25 FPS Distributed Air Velocity

40 35 30

1 4 0 0 ° F

Limit for Finned Tubular for Normal Life Expectancy

40

1 2 0 0 ° F

Limit for Finned Tubular for Normal Life Expectancy

1 2 0 0 ° F

35 30 25 20 15 10 5

1 0 0 0 ° F

25

2 0 0 ° F 4 0 0 ° F 6 0 0 ° F 80 70 60 50 40 30 20 10 0 Watt Density in W/In 2 of Effective Length 8 0 0 ° F 8 4 0 ° F 1 0 0 0 ° F Finned Tubular Units

20 15 10

8 0 0 ° F 6 4 0 ° F 6 0 0 ° F 4 0 0 ° F 2 0 0 ° F 80 70 60 50 40 30 20 10 0 Watt Density in W/In 2 of Effective Length

Tubular Units

Tubular Units

5

Finned Tubular Units

0

200

400

600

800 1000 1200 1400

Outlet Air Temperature (°F)

0

200

400

600

800 1000 1200 1400

Outlet Air Temperature (°F)

Graph G-153-1 — Fintube ® & Tubular Heaters Sheath Temperatures with 9 FPS Distributed Air Velocity

Graph G-156-1 — Fintube ® & Tubular Heaters Sheath Temperatures with 36 FPS Distributed Air Velocity

40

1 2 0 0 ° F

1 4 0 0 ° F

Limit for Finned Tubular for Normal Life Expectancy

40

35

Limit for Finned Tubular for Normal Life Expectancy

1 0 0 0 ° F

35 30 25 20 15

30

1 0 0 0 ° F

25 20 15 10 5

8 0 0 ° F

2 0 0 ° F 4 0 0 ° F 6 0 0 ° F 8 0 0 ° F 8 4 0 ° F 80 70 60 50 40 30 20 10 0 Watt Density in W/In 2 of Effective Length

6 0 0 ° F 6 4 0 ° F 4 0 0 ° F 2 0 0 ° F 80 70 60 50 40 30 20 10 0 Watt Density in W/In 2 of Effective Length Finned Tubular Units

Tubular Units

Finned Tubular Units

Tubular Units

10

5

0

200

400

600

800 1000 1200 1400

Outlet Air Temperature (°F)

0

200

400

600

800 1000 1200 1400

Outlet Air Temperature (°F)

TECHNICAL

INFORMATION

I-19