LIT-PX131 - Tank Heating Systems

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25,000 20,000

120 110 100

500

15,000

30,000

400

90 80 70

10,000

3,000,000 2,000,000

20,000

300

7,000

60

250

5,000 4,000

60

1,000,000 700,000 500,000 400,000 300,000 200,000

10,000

2,000 1,500 1,000

300 200 150 100

50

200

50 45 40 35

7,000

3,000

700 500 400 300 200 150 100 Surface Area of Cylindrical Section of Tank (ft 2 ) kW for Uninsulated Tank* 70 50 40 30 25 20 15 10 30 25 20 18 16 14

40 35

5,000 4,000 3,000

2,000 Surface Area of the Two Tank Ends (ft 2 ) 1,500 1,000 700 30 25 20 15

150

100,000 70,000 50,000 40,000 30,000 25,000 20,000 10,000 7,000 5,000 4,000 3,000 2,000

2,000

100 90 80

1,500

70 50 40 30 20 15 10

Volume (gal)

500 400 300 250 200

1,000

7 5 4 3 2 1.5 1 0.7 0.5

Diameter of Tank (ft)

70

Length or Height of Tank (ft)

Temperature Differential (°F)

700

60

500 400 300

kW for Tank Insulated with 3” Fibrous Glass

50

12

10 9 8 7

150

7 5 4

40

10 9 8

100

200

30

70

6

50 40 30

1,000 900

100

5 4.5

* Based on still air

1. Connect 10’-0” on scale with 17’-0” on scale by a straight line . Intersecting this line with scale will give the surface area of the cylindrical portion of the tank as approximately 550 ft². Note: Intersection of line with scale will show tank volume in gallons. (This is often helpful because the dimensions of the tank can be approximated if only the volume is known.) 2. To determine the total area of both heads of the tank, draw horizontal line through 10’ on scale and read the area of both heads on scale as 155 ft².

3. Adding the results of Step 1 and Step 2 will provide the total surface area of the tank: 705 ft². Connect 705 on scale by a straight line to 300°F (325°F minus 25°F) on scale and read kW recommended where line intersects scale . For a tank insulated with 3” fibrous glass, 35 kW will be required. An uninsulated tank will need about 240 kW.

Note:This nomograph can tell you the recommended kW for maintaining tank temperatures; additional heating capacity is needed to heat materials from a “cold start.” Consult your Chromalox Representative for expert advice in determining the required additional capacity.

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