AIR FLOW RATES

Ideal Rates for Standard Smelter Sizes
Aneonometer KpH x 8.17 with 2.5 diameter tube
Chart to right converts aneonometer KpH to LpM

DIAMETER AREA CM @ 1.2 L/M SPEED KpH @ 1.5 L/M SPEED kph
20
314
377
46
565
69
25
491
589
72
883
106
30
707
848
102
1272
155
28 x 28
784
941
115
1411
173
30
706
950
116
1400
170
VOLUME TO SPEED
LpM KpH
   
400 49
500 61
600 73
700 86
800 98
900 110
1000 122
1100 135
1200 147
1300 159

Using the method proposed by Sauder & Williams, the ideal air flow rate is 1.2 - 1.5 Litre per minute for each square centimetre of cross section area at tuyere level.

Although Iron certainly *can* be produced with lower air rates, high volume air has proven to create dense, 'puck' like blooms, most like historic samples.

 

Air Rates Using Standard Vaccum Cleaner Blower
With light dimmer switch to control speed = volume
This equipment used for smelts (at Wareham) # 6 through 28

Measured October 28, 2006

SETTING GAUGE KPH M / Min CM / Min FLOW L / Min VOLUME L / Min
    x 1000 / 60 x 100 / 1000 for 2.5 cm dia
           
A
20
333.33
33333
33.3
164
1/4
40
666.67
66667
66.7
327
1/2
56
933.33
93333
93.3
458
3/4
73
1216.67
121667
121.7
597
B
86
1433.33
143333
143.3
703
1/4
96
1600.00
160000
160.0
785
1/2
103
1716.67
171667
171.7
842
3/4
110
1833.33
183333
183.3
899
C
119
1983.33
198333
198.3
973
1/2
127
2116.67
211667
211.7
1038
D
130
2166.67
216667
216.7
1063
1/2
135
2250.00
225000
225.0
1104
+
140
2333.33
233333
233.3
1145

Measured 10/15/07

SETTING GAUGE KPH VOLUME L / Min
    for 2.5 cm dia
     
Red Dot (A) 21 174
1/4 33 274
1/2 52 432
3/4 59 490
B 67 556
1/4 81 672
1/2 87 722
3/4 93 772
C 97 805
1/4 102 847
1/2 106 880
3/4 109 905
D 111 921

Comparision - Blower volume over time

SETTING
10/26/08
10/15/07
10/27/08
       
Red Dot (A)
164
 174  
1/4
327
 274 240
1/2
458
 432 413
3/4
597
 490 461
B
703
 556 518
1/4
785
 672 636
1/2
842
 722 690
3/4
899
 772 747
C
973
 805 779
1/4
1038
 847 843
1/2
1063
 880 890
3/4
1104
 905 922
D
1145
 921 954

Air Volumes - Viking Age Blacksmith's Bellows
Tested October 2007
See full report ' Bellows Air Test '
NAME: STROKES/Minute no pressure test
m/s (L/min)		 pressure test 1
m/s (L/min)		 pressure test 2
m/s (L/min)		 pressure test 3
m/s (L/min)
Peter:
81
11.1 (209)
7.1 (133)
6.9 (130)
5.1 (103)
Kevin:
76
13.6 (256)
7.3 (137)
7.1 (133)
4.9 (92)
Neil:
75
11.7 (220)
7.1 (133)
7.1 (133)
4.3 (81)
Darrell:
69
9.3 (175)
6.3 (118)
5.5 (103)
3.2 (60)
Vandy:
108
11.2 (211)
8.4 (158)
7.5 (141)
5.4 (102)
Ken:
117
10.0 (188)
8.0 (150)
6.7 (126)
5.2 (98)
AVERAGE:
88
11.15 (209)
7.4 (139)
6.8 (128)
4.7 (88)

Air Volumes - Theoretical Viking Age Smelter Bellows
Tested May 26, 2012
Operator
strokes
velocity
volume
pressure
km/hr
litre/minute
ounce/inch2
psi
inches H20
mm mercury
low
high
average
Richard
76
38.5
41.5
40
327
1
0.06
1.7
3.2
86
37
41
40
327
1.5
0.09
2.6
8.4
Mark
86
36
40
38
310
1.5
0.09
2.6
8.4
90
47
52
47
384
3
0.19
5.2
16.8
Darrell
86
41
43
43
351
1.25
0.23
2.2
7.0
86
39
42
41
335
1.5
0.09
2.6
8.4
Neil
86
43
45
44
359
1.75
0.11
3.0
9.8
84
46
48
48
392
1.5
0.09
2.6
8.4
averages
85
41
44
43
348
1.6
0.12
2.8
8.8
area
27 dia
572 cm2
ideal volume
at 1.2
686
at 1.5
858

This test done at the start of 'Icelandic 5', with full charcoal inside a 27 cm ID furance x 58 cm tall.
Individual operators worked a roughly 5 minute cycle on the bellows with measurements made over 30 seconds.
Figures in itallics were generated mathmatically. Richard & Darrell have past experience with this unit.

 


Last Updated on 5/29/12
By Darrell Markewitz
Email: smelt@warehamforge.ca

Text and photography © 1998 - 2012, Darrell Markewitz