Efficient gas absorption depends on the following:
- Intimate contact
- Efficient Heat Transfer
This is achieved in a Falling Film Absorber which is essentially a shell & tube heat exchanger in which both gas to be absorbed and absorbing liquid flow co-currently downward with extraction of heat by circulation of coolant in the shell. The abssorbing liquid is circulated through a tank till desired concentration is achieved. The liquid flows at such a rate that the tubes do not flow full of the liquid but instead, descends by gravity along the inner walls of the tubes as a thin film. Obviously, this produces a much greater linear velocity for a giver rate flow than could be obtained if the tube flowed full.
The equipment works as a number of water cooled-wall columns in parallel and each tube is provided with distribution system on top to effect uniform distribution of both liquid and gas and also formation of a thin liquid film on the inner surface of the tube.
SALIENT FEATURES
- The heat of absorption is continuously removed. This ensures better absorption and product concentration as compared with conventional packed tower
- Low residence time and operating temperature ideally suited to heat sensitive materials.
- Borosilicate glass and PTFE contact parts ensure corrosion/ contamination free operation
- Both standard and custom built units are available.
- Capable of operating from zero to maximum gas flow rate.
- Ease of installation due to light weight.
- Trouble free and consistent performance with minimal attention.
- Wide application e.g. HCl, HBr, NH , SO , H S, Br etc
- Less cost.
- Negligible pressure drop compared to conventional columns.
- Compact design Sleek and slender
- Both heat and mass transfer operations are incorporated in a single equipment.
- Very high heat transfer coefficient as the liquid falls instead of flowing.
- Scaling of process fluid is minimal due to high velocity and ease of cleaning by simple acid circulation.
- Hot conditions are eliminated at all stages namely pipe, tanks and pumps etc
LIMITATIONS
- Not recommended for gases containing high proportion of inert (insoluble).
- Not applicable if the gases are not highly soluble
SPECIFICATIONS
|
Sr. No. |
Nominal Size (mm) |
Absorber Area (m2) |
No.of Tubes/ Tube OD (mm) |
Max.Gas Absorption Rate (Pure HCl) * (kg/hr) |
Max.Acid Prod. Rate (As 30 % HCl) (kg/hr) * |
Height (m) |
|
1. |
80 |
1.00 |
4/ 20 |
30 |
100 |
4400 |
|
2. |
100 |
1.76 |
7/ 20 |
60 |
200 |
4500 |
|
3. |
150 |
4.80 |
19/ 20 |
150 |
500 |
4600 |
|
4. |
225 |
7.80 |
31/ 20 |
250 |
833 |
4920 |
|
5 |
300 |
15.30 |
61/ 20 |
500 |
1667 |
5050 |
|
6 |
400 |
36.00 |
143/ 20 |
1175 |
3917 |
5300 |
|
7 |
450 |
47.00 |
187/ 20 |
1500 |
5000 |
5700 |
|
8 |
600 |
84.00 |
333/ 20 |
2700 |
9000 |
5800 |
