Van Gas silica
gel desiccant beads consist of 97% silicon dioxide and 3% alumina. The bead shape, uniform particle size and high bulk density of the dry bed desiccant combine to ensure optimum gas flow without channeling. Also, minimal dusting occurs within the tower of the dryer due to the physical characteristics of this adsorbent desiccant.
An large network of interconnecting microscopic pores exist within a single granule of silica gel. This network of pores attracts and retains moisture via physical adsorption and capillary condensation. Even once the silica gel desiccant has become completely saturated, the beads appear to be and feel dry to the touch.
Since silica gel fractures in the presence of liquid water, it must be protected by a 10% to 15% (by weight) layer of
activated alumina as a water buffer on the inlet side of
the desiccant bed.
Van Gas silica gel desiccant is available in two variations; indicating and non-indicating. Dew Points to -40 F and lower may be achieved with silica gel desiccant depending on the gas dryer design and operating conditions.
Physical
Properties |
|
Non-Indicating |
Indicating |
|
| Color
and form |
Translucent
brown bead |
Translucent
blue bead |
| Size |
3.5
mm (.14") |
3.5
mm (.14") |
| Bulk
Density |
49
lbs/cu.ft. |
49
lbs/cu.ft. |
| Surface
area |
3.67
x 10 6 sq ft/lb |
3.67
x 10 6 sq ft/lb |
| |
|
|
| Static
adsorption |
|
|
| Humidity |
|
|
| 100%
RH |
39.0% |
37.0% |
| 90%
RH |
36.3% |
34.0% |
| 60%
RH |
33.3% |
29.0% |
| 10%
RH |
6.4% |
4.9% |
|
|
|
|
Non-Indicating
Silica Gel |
Indicating
Silica Gel |
Silica
Gel Package Sizes |
| Non-Indicating |
Indicating |
|
| 33-0315 |
5
lb pail |
33-0316 |
5
lb pail |
| 33-0243 |
25
lb pail |
33-0246 |
25
lb pail |
| 33-0244 |
50
lb bag |
33-0247 |
50
lb bag |
| 33-0245 |
330
lb steel drum |
33-0248 |
330
lb steel drum |
1.
High moisture retention capacity under dynamic conditions
Used in some heated type regenerative dryers. Under dynamic
conditions, a higher design capacity rating and lower regeneration
temperature can be used. Instead of increasing your cycle time, you can switch from activated alumina to silica gel and not lose operating capacity.
2. Uniform bead shape
This shape provides lower pressure drop and less abrasion
than granular types. Smooth silica gel beads also pack uniformly to
minimize channeling.
3. Provides visual check of
desiccant condition (indicating type only)
Desiccant beads are impregnated with a moisture indicator. The color
changes from blue to pink as moisture is adsorbed. Reduced
capacity of this type is due to the presence of indicator
material in its pores.
