Cast-iron finned tubes
Special hexagonal and quadrangular cast-iron finned tubes are manufactured by Technológia
Mérnöki Iroda Kft, Budapest. The cast-iron elements are 200 mm long and they consist of
hexagonal or quadrangular finned parts beaded with clearance fit to a carbon or stainless
steel and with high pressure expanded to assure the metal-to-metal contact between the
iron cast and the core tube.
| Cast-iron finned tubes are employable in the following circumstances: |
| • |
Heat recovery of high temperature max (700 °C) corrosive and erosive smoke gas,
under dew point outlet temperature, |
| • |
Heat recovery from waste heat of incinerator and dangerous waste burner plants, |
| • |
In feed water pre-heater of coal, oil and gas burning economisers, |
| • |
For industrial heating tube registers. |
Mean technique parameters:
Coring tube
Material: St. 37.4, St 35.8 I-III, stainless steel
| Dimensions: |
normal steel |
stainless steel |
| Ø25 x 2,6 |
Ø25 x 2 |
| Ø38 x 2,6 |
Ø38 x 2 |
| Ø57 x 2,6 |
Ø57 x 2 |
Cast iron finned tubes:
| Core tube (mm) |
Ø25 |
Ø38 |
Ø57 |
Ø57 |
| Dimension of the fins |
60 hexagonal |
95 x 95 |
120 x 145 |
145 x 145 |
| Pitch of the fins (mm) |
11,1 |
15,4 |
10 |
12,5 |
| Number of fins (fin/m) |
90 |
60 |
100 |
80 |
| Mass (kg/m) |
12 |
19,5 |
43 |
53 |
| Inside heat-transfer surface (m2/m) |
0,0625 |
0,104 |
0,160 |
0,160 |
| Surface relation |
9,7 |
10,2 |
18,7 |
19,1 |
| Outside heat-transfer surface (m2/m) |
0,606 |
1,06 |
3 |
3,05 |
| Pitch of the tubes |
| In the direction of the gas flow |
65 |
100 |
150 |
150 |
| Perpendicular to the direction of the gas flow |
75 |
100 |
130 |
150 |
| Overall heat transfer coefficient to the inside surface
(W/m2K) by creating heat water by 0,5 m/s water velocity if the flue gas velocity is: |
| 4 m/s |
420 |
440 |
800 |
800 |
| 5 m/s |
480 |
500 |
900 |
900 |
| 6 m/s |
530 |
550 |
990 |
990 |
|
|
