DriSteem Vapor-logic3 Especificaciones descargar pdf (Pagina 16)

P a g e 1 6 • D R I - S T E E M V a p o r m i s t h u m i d i f i e r

C a l c u l a t i n g n o n - w e t t i n g d i s t a n c e s

Sample exercise

To learn more about how to specify a dispersion unit based on non-

wetting distance, read the sample problem below. For purposes of

this sample problem, assume you have chosen to use Ultra-sorb

units because you want pre-assembled panels.

Assume the air entering the dispersion assembly is 20% RH and the

air leaving the zone of humidification needs to be 70% RH. Design

for a non-wetting distance of 24" (610 mm) maximum.

Solution

Refer to the graph on Page 17: Ultra-sorb non-wetting distances.

Find 20% entering RH. Proceed vertically until you intersect the

70% leaving RH line. Draw a line horizontally from that point to

the right to see that for 24" (610 mm) of non-wetting distance, 6"

(152 mm) tube spacing would be the closest match.

Verify capacity

From Table 17-1: Ultra-sorb tube spacing and capacity on

Page 17, note that for 6" (152 mm) spacing, maximum capacity is

18 lbs/hr/ft

(88 kg/h/m

). Multiply this value by the active face

area of the Ultra-sorb to determine if the unit will produce adequate

output capacity. If the capacity is inadequate, go to the next smaller

tube spacing.

Steam absorption considerations

1. Non-wetting distance is the dimension downstream from the

leaving side of the steam dispersion assembly to the point where

wetting will not occur, although wisps of steam may be present.

Solid objects at duct air temperature, such as coils, dampers,

fans, etc., downstream of this dimension will remain dry.

C A U T I O N ! Non-wetting distances described in this catalog

do not apply when installing a steam dispersion assembly

upstream of filter media. If you need to install a steam dispersion

assembly upstream of filter media, consult your representative or

DRI-STEEM directly for special recommendations.

3. Note that the rise (

Δ) in RH (the difference between entering and

leaving RH) has a direct bearing on the non-wetting distance. As

the rise increases, more vapor needs to be dispersed into the air,

and thus the non-wetting distance increases.

4. Uneven airflow over the cross-section of a dispersion assembly

can result in nonuniform mixing of steam with air which, in

turn, will adversely affect the non-wetting distance.

Notes:

• Final equipment selection should account

for condensate loss. See the DRI-STEEM

Design Guide for steam loss tables.

• Dispersion assembly should accommodate

maximum output capacity of humidifier.

1 2 ... 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Comentarios a estos manuales

Sin comentarios

DriSteem Vapor-logic3 Especificaciones Pagina 16

Comentarios a estos manuales