Direct Steam Injection Humidifiers
User Manual: Direct Steam Injection Humidifiers
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Direct steam
injection humidifiers
2
Direct steam injection gives
quality control of air humidity.
Research and development in separation, the use of lightweight
stainless steel combined with a constant temperature lance system, has
created new standards in direct steam humidification. These features
provide quality, efficiency and all round value for money.
Effective moisture separation
The major factors that lift the total performance of Spirax Sarco S.I. humidifiers above
other manufacturers are:
A highly effective combination of centrifugal, vortex and baffle separation which
ensures the driest steam is available at all times.
The twin chamber separator which supplies the lance and pre-heat circuit.
The capability to handle high steam loads without the loss of separator efficiency.
Low mass, with high strength, allows fast warm-up.
The consistent condensate discharge without re-entrainment.
Effective steam injection
Once the separator has completed its job, it is necessary to then deliver the steam into the air as
a gas, (not as a water laden atmosphere). This is achieved through the Spirax Sarco lance by:
Continuous heating over the full length of the lance.
Ejection nozzles which take steam from the hottest part of the lance.
Low mass for rapid pre-heating.
The constant re-evaporation of any condensate in the lance.
The extremely small lance surface area reduces the cooling effect
and air flow resistance.
Why choose S.I. humidifiers?
The benefits of choosing S.I. humidifiers over other manufacturers has
to be the simple fact, it is an effective system which ensures:
High steam output per metre of lance.
Very low noise levels.
Simplified duct and piping requirements.
Close spacing where multiple lances are needed.
Low steam ejection velocity for efficient air / steam mixing.
●The cleanliness of Legionella free steam.
User benefits
Stainless steel separator
combining centrifugal,
vortex and baffle separation.
●Spirax Sarco's guarantee of worldwide technical support,
knowledge and service.
●Ultra low noise levels.
●Few working parts giving minimal maintenance.
●Simple construction in quality stainless steel.
●Wide product choice.
●Small, compact and lightweight for easy low cost installation.
●Rapid moisture absorption with minimal temperature rise.
S.I. steam injection humidifiers can be adapted to a wide range of duct sizes,
temperatures and air velocities, with few additional components required.
Alternative makes of valve and actuator can be supplied.
3
Option of either pneumatic or
electric actuators
Stainless steel steam injection
nozzles facing into air flow for
rapid absorption of moisture.
All stainless steel lance.
Balanced pressure steam trap to
drain lance heating circuit.
Float type steam trap to drain
separator.
Separate internal stainless steel
lance heating system.
Option of screwed
or flanged valves
in stainless steel,
SG iron, bronze or
other materials.
Steam
injection
nozzles
Section through lance showing heating system
Internal
lance
heating
system
Air flow
Spring
clips
4
Typical applications
The most common application for humidification by direct steam injection
occurs in air supply ducts used for control within living and office environments.
The versatile Spirax Sarco S.I.humidifier can easily accommodate the
wide variety of applications and installations encountered,
some of which are shown below.
Note: These illustrations are general with some components omitted for clarity.
*Insertion of lance can be from either left or right side of ducting.
Multiple horizontal
lances in horizontal duct*
Vertical lance in horizontal duct
Horizontal lance in horizontal duct* Horizontal lance in vertical duct*
5
Product selection
The best diffusion of steam into the air flow is achieved by
spreading the outlet nozzles of the lance(s) evenly within the duct, vertically and horizontally.
This is achieved by following the example through the five steps below.
2. Select the lance
Select the recommended number of lances required
from Table 1 to match the known duct height.
Final product selection and specification
From the above example: 1 x Spirax Sarco S.I. humidifier for 110 kg / h at 1.5 bar g;
1 x Type 20 separator with DN20 LE31 valve screwed BSP,
with EL3502SE actuator for 24 V operation VMD control signal, and 3 x Type 20 model 6 lances.
Table 1
Duct height in mm Number of lances
up to 1 000 1
1 000 - 1 700 2
1 700 - 2 200 3
2 200 - 2 600 4
2 600 and above 5
Number of recommended lances required = 3
1. The known data
Duct size 1 800 mm high and
1 800 mm wide
Steam pressure 1.5 bar g
Required maximum
steam flowrate 110 kg / h
Spirax Sarco valve Screwed
Valve actuation Electric
Actuator voltage 24 Vac 50 / 60 Hz
Control signal VMD
Duct width in mm
Maximum 450 630 900 1 200 1 470 1 780 2 080 2 380 2 690 3 000 3 300 3 610 3 950
Minimum 280 450 630 900 1 200 1 470 1 780 2 080 2 380 2 690 3 000 3 300 3 610
3. Select the lance model
Select the lance model from Table 2 to match the known duct width.
Lance model 11.52 3 4 5 6789101112
Recommended lance model = 6
Table 2
4. Select the system
Select the system that will handle the known capacity (Type 20 or Type 40)
to obtain the required valve Kv. See page 6 and the example below.
5. Select the control valve and separator
Having selected the required valve Kv, the actual valve size and actuator can now be found from the chart headed
Valve selection on page 7. Always select the next highest valve Kvs, to the Kv required.
Recommended control valve is a DN20 LE31 with screwed BSP connections.
Recommended actuator is a EL3502SE for 24 V operation VMD control signal.
It will be seen that the Type 20 system for multiple lances requires a Kv value of 5.8
Type 20
system
with
multiple
lances
Supply pressure
0.25 bar g 0 6 12 18 24 30 36 42
0.5 bar g 0 10 20 30 40 50 60 70
1.0 bar g 0 15 30 45 60 75 90 105
1.5 bar g 0 20 40 60 80 100 120 140
*2.0 bar g 0 22 44 66 88 110 132 154
Steam
load
kg / h
*Recommended maximum inlet steam pressure to separator for quiet operation of the humidifier. For operating pressures above 2 bar g consult Spirax Sarco.
Lance model 1 1.5 to 12
110 kg / h
Kv 1
Kv 2
Kv 3
Kv 4
Kv 5
Kv 5.8
Kv 7
6
Kv 25
System sizing
Lance model 1 1.5 2 3 to 12
*Recommended maximum inlet steam pressure to separator for quiet operation of the humidifier. For operating pressures above 2 bar g consult Spirax Sarco.
Type 20
system
with
single
lance
Type 40
system
with
single
lance
Type 40
system
with
multiple
lances
Type 20
system
with
multiple
lances
Supply pressure
Supply pressure
Supply pressure
Supply pressure
0.25 bar g 0 19 38 57 76 95 114 133
0.5 bar g 0 28 56 84 112 140 168 196
1.0 bar g 0 40 80 120 160 200 240 280
1.5 bar g 0 50 100 150 200 250 300 350
*2.0 bar g 0 58 116 174 232 290 348 406
0.25 bar g 0 6 12 18 24 30 36 42
0.5 bar g 010203040506070
1.0 bar g 0 15 30 45 60 75 90 105
1.5 bar g 0 20 40 60 80 100 120 140
*2.0 bar g 0 22 44 66 88 110 132 154
0.25 bar g 0 35 70 105 140 175
0.5 bar g 0 55 110 165 220 275
1.0 bar g 0 80 160 240 320 400
1.5 bar g 0 100 200 300 400 500
*2.0 bar g 0 115 230 345 460 575
Lance model 1 1.5 to 12
Lance model 1 1.5 2 3 to 12
0.25 bar g 0 6 12 18 24 30 36 42
0.5 bar g 010203040506070
1.0 bar g 0 15 30 45 60 75 90 105
1.5 bar g 0 20 40 60 80 100 120 140
*2.0 bar g 0 22 44 66 88 110 132 154
Kv 25
Kv 7
Lance model 1 1.5 2 3 4 to 12
Steam
load
kg / h
Steam
load
kg / h
Steam
load
kg / h
Steam
load
kg / h
Kv 1
Kv 7
Kv 6
Kv 5
Kv 4
Kv 3
Kv 2
Kv 5
Kv 10
Kv 15
Kv 20
Kv 1
Kv 2
Kv 3
Kv 4
Kv 5
Kv 6
Kv 5
Kv 10
Kv 15
Kv 20
7
approximate in millimeters
Dimensions
Valve selection
Valve selection Actuator selection
Kvs Size Pneumatic 230 Vac Electric 0 – 10 Vdc
Cast iron 0.2 - 1.0 bar VMD 24 V 24 V
Screwed Flanged spring range VMD
0.4 DN15 LE31 LE33 PN3220 EL3501SE EL3502SE EL3512SE
1.0 DN15 LE31 LE33 PN3220 EL3501SE EL3502SE EL3512SE
1.6 DN15 LE31 LE33 PN3220 EL3501SE EL3502SE EL3512SE
4.0 DN15 LE31 LE33 PN3220 EL3501SE EL3502SE EL3512SE
6.3 DN20 LE31 LE33 PN3220 EL3501SE EL3502SE EL3512SE
10.0 DN25 LE31 LE33 PN3220 EL3501SE EL3502SE EL3512SE
16.0 DN32 LE31 LE33 PN3320 EL3501SE EL3502SE EL3512SE
25.0 DN40 LE31 LE33 PN3420 EL3501SE EL3502SE EL3512SE
Separator
Weight 1.46 kg 3.7 kg
Lance model Type20 Type40
Assembly Type20 Type40
DN15 AScrewed 213
Flanged 300
DN20 AScrewed 192 340
Flanged 290 440
DN25 AScrewed 330
Flanged 405
DN32 AScrewed 340
Flanged 430
DN40 AScrewed 270
Flanged 375
C270 395
D85 120
E208 316
F Ø 105 152
G40 48
H165 246
J Ø 38 54
K60 60
LM10 M10
M50 min. to 80 max.
DN15 B345 375 375
DN20 B345 375 375
DN25 B355 385 385
DN32 B383 390 390
DN40 B383 390 390
Actuator type Pneumatic VMD 0 – 10 Vdc
Limiting conditions Type 20 / 40
Separator body design conditions PN6
Maximum operating pressure 4 bar g
Maximum operating temperature 152°C
Escutcheon plates
T115 115
V65 65
W55
X17.5 25.5
Pipe
connections
BSP (ISO)
N¼" ¼"
P¼" ¼"
Q½" 1"
R¾" 1½"
S1" 1½"
Type40
Duct wall
Escutcheon plates
X
W
W
Q
R
R
P
N
N
K
L
Clearance hole required
in duct to install lance
JØ
G
M
S
Assembly
Type20
B
E
D
A
C
Y
Z
V
T
Y338 345
1Z138 137
Weight 0.88 kg 1.54 kg
Y513 520
1.5 Z173 152
Weight 1.14 kg 1.97 kg
Y688 695
2Z192 207
Weight 1.4 kg 2.39 kg
Y958 965
3Z183 197
Weight 1.8 kg 3.03 kg
Y1268 1275
4Z208 207
Weight 2.26 kg 3.78 kg
Y1528 1535
5Z212 203
Weight 2.65 kg 4.4 kg
Y1838 1845
6Z298 207
Weight 3.11 kg 5.15 kg
Y2138 2145
7Z214 201
Weight 3.65 kg 5.87 kg
Y2438 2445
8Z210 297
Weight 4.0 kg 6.59 kg
Y2748 2755
9Z216 199
Weight 4.46 kg 7.34 kg
Y3058 3065
10 Z238 237
Weight 4.92 kg 8.08 kg
Y3358 3365
11 Z218 197
Weight 5.37 kg 8.8 kg
Y3688 3675
12 Z208 237
Weight 5.83 kg 9.55 kg
H
FØ
Note: KE valve option and EL3500 and PN5000 series actuators also available. Where positioners are required for any valve, consult Spirax Sarco.
Other valves available upon request.
CH Issue 6SB-P795-05
Technical information
Some of the products shown
may not be available in certain markets.
DIHUM
Materials
1 Separator Shell Stainless steel 304 (S14 / S11)*
Internals Stainless steel 304 S11*
Body Stainless steel BS 3146 ANC3B*
Tracer tube Stainless steel 304L*
2 Lance Main tube Stainless steel 304L*
End cap Stainless steel 304 S11*
Spring clips Stainless steel 304 (S14 / S11)*
3 Nozzles Stainless steel - standard*
4 Pipe fittings Malleable iron*
5 Compression fittings Bright zinc plated mild steel
Optional stainless steel 316L
6 Pre-heat tracer pipe 8 mm O / D tube - Spirax Sarco or
customer to supply
7 Name-plate Aluminium
See specific installation and maintenance
8 Actuator instructions for model supplied
9 Valve LE31 and LE33 CI DIN 1691 GG20
KE63 Stainless steel DIN 17445 4581
10 Tracer
system MST21(E) Stainless steel
11 Lance interconnecting pipework - installer to supply
12 Escutcheon plates Galvanised steel
13 FT14 drain trap SG iron DIN 1639 GGG40
Assembly information
Where Spirax Sarco supply the steam control
equipment, the separator and valve would be
dispatched assembled. Alternatively, the separator,
valve and actuator can be dispatched fully assembled
when requested, to simplify final installation.
Actuators can be pre-commissioned if the control
signal is known. When the steam control is not part of
the humidifier order, the piping components will be
supplied partly assembled to the separator, for final
assembly by the installer.
The separator and each lance are supplied with
2 x 8 mm O / D tube compression fittings (5):
1 for the tracer supply take-off from the top
of the separator,
1 each for the inlet and outlet connections
for the lance heating circuit and
1 for the inlet to the tracer drain trap (10).
A Spirax Sarco balanced pressure thermostatic trap
(10) type ¼" MST21 (E) should be used for this
application.
The preheater in the lance can be supplied with
steam direct from the separator at the using steam
pressure as shown, or alternatively from an
independent source up to a maximum of 4 bar g.
The separator drain (Q) should be fitted with a
Spirax Sarco float trap (with automatic air vent) to
continuously discharge collected condensate.
Typical specification
The humidifier shall be a Spirax Sarco S.I. type of
the direct steam injection design, having a stainless
steel twin section separator with internal cyclonic
and baffle moisture separation to provide dry
saturated steam.
The injection lance in stainless steel shall be steam
preheated, and utilise stainless steel nozzles.
The control valve shall be a Spirax Sarco
2-port valve with a spring reserve electric actuator
suitable for a 24 Vac supply.
13
Q
1
8
10
11
Multiple lances
6
6
52
5412
9
5
Single lance
7
3
4
* 316L Stainless steel option available
Spirax-Sarco Limited, Charlton House,
Cheltenham, Gloucestershire, GL53 8ER UK.
Tel: +44 (0)1242 521361 Fax: +44 (0)1242 573342
E-mail: Enquiries@SpiraxSarco.com
Internet: www.SpiraxSarco.com
© Copyright 2000 Spirax Sarco is a registered trademark of Spirax-Sarco Limited
