The selection and installation calculation of silicon carbide rod is a relatively rigorous problem. If the calculation is not in place, the temperature will rise slowly. I will introduce several calculation and installation methods of silicon carbide rod

There are two methods to calculate the diameter of silicon carbide rod*

(1) Known "effective length"

The diameter and number n of silicon carbide rods are determined according to the effective length. The calculation steps and formulas are shown in table 12-38.

Calculation example:

It is known that the power of electric furnace is 14kw, three-phase power supply, the most commercial working temperature] 350ec, and the furnace size (length x width x height) is

520mm x 250mm x 220mm, the silicon carbide rod vertical gun is required to be arranged two days later. Ask for the size and size of silicon carbon beech,

And select the converter.

Solution:

1) according to the maximum working temperature of 1350 ° C, according to figure 12-1! Take element surface load / > = 10W / cm2,

2) Calculate the total cell efficiency product SA = 1400 (cm2)

3) According to table] 2-40, the size of silicon carbide rod is 18 / 250 / 350; At this time, it can be found that the silicon carbide rod s = 14k4cm / piece,

R =1.3Q)

4) number of silicon carbide rods n = 1400 / 141.2 = 9.9. Since it is a three-phase power supply, the number shall be a multiple of 3, and

one hundred and forty-one point four

Promote the even number, so take 12 reports and twist 6 on the side. Every two strings are a group of I

5) The distance between each two grates (a = y ^ = 74.5cmm), greater than 2 < / (= 36oim) is qualified

T+ 1

6) Element resistance per phase = = 2 Xi 3 = 2.6 (£ 2) (two groups connected in series to form DDH)

7) secondary voltage at full load of transformer £ 2.6x2 3X 10* =78 (V)。 Power per phase IV = ^=

six

2.3(kW)»

seventy

8) Phase current

9) Line current 〜 58 52 (a),

10) Electricity [in the regulation range = (0.35 ~ 2.0) > X78 = 27.3 ~ 156 (V)