1. Effect of gravity on coalescence
with and without drainage structure in horizontal & vertical orientation
S.U. Patel and G.G. Chase 1
ABSTRACT
Aerosol filtration is carried out to separate liquid particles from the air stream. The focus of this project is to study the effect of gravity on filtration and separation. Gravity will enhance the drainage of liquid from the filter media increasing the removal efficiency and reducing pressure drop. It will be studied by performing the coalescence filtration experiment by positioning the disc shaped filters in vertical direction relative to air stream.
Aerosol filtration, being an economic unit operation has many industrial applications like dehumidification, automobile filters; exhaust filters which separates particles as well as liquid droplets from air source which is important in concern with environmental aspect.
This work will be done to test the performance of disc shaped filters under gravitational field by positioning them vertically to air flow. The performance of disc shaped filters with horizontal position has been studied to evaluate the quality factor, pressure drop and filtration efficiency. A similar approach will be adopted for study the effect of gravity.
OBJECTIVE
The hypothesis of the work is to study the effect of gravitational force on coalescence filtration and separation.
DRAINAGE CHANNEL
DRANAIGE CHANNEL EXPERIMENTS
RESULTS
Horizontal Orientation
Polypropylene mesh
(500 micron pore opening, 610 filament thickness)
Both end
drainage
Inclined
drainage
Outlet
drainage No
drainage
Inlet
drainage
Middle
drainage
Outlet drainage
Vertical Orientation
No drainage
Inlet drainage
Middle drainage
Both end drainage
Inclined drainage
Microscopic image of drainage structure
IMPROVEMENT IN QUALITY FACTOR
Sr. No.
Case study
Quality factor (KPa-1)
Horizontal
Vertical 1.
No Drainage Channel
0.180
0.481 2.
Inlet Drainage Channel
0.406
0.173 3.
Middle Drainage Channel
0.187
0.090 4.
Outlet Drainage Channel
0.364
0.343 5.
Both End Drainage Channel
0.424
0.223
167 %
125 %
102 %
135 %
HYPOTHESIS OF WORK
INCLINED ANGLE
Sr. No.
Case Study
Quality factor (KPa-1)
Horizontal
Vertical 1. 00
0.135
0.155 2.
300
0.280
0.167 3.
450
0.774
0.052 4.
600
0.138
0.118 5.
750
0.262
0.124
Gas flow out
Gas flow in
Drainage
473 %
94 %
Higher entrainment
Less drainage
Increased Pressure Drop
Decrease in Quality Factor
107 %
Gas flow in
Gas flow out
Drainage
Drainage structure
OPTIMUM BED LENGTH
Sr. No.
Bed length (inch)
Efficiency (%)
Delta P (KPa)
Quality factor (KPa-1) 1.
0.25
45.36
6.34
0.073 2.
0.3
59.10
5.84
0.159 3.
0.375
80.77
6.23
0.299 4.
0.45
95.35
9.16
0.348 5.
0.5
97.42
9.58
0.418
Less entrainment
More drainage
Reduced Pressure Drop
Increase in Quality Factor
HORIZONTAL FLOW
SUMMARY OF PREVIOUS WORK
Developed recipe to make thick filter samples using Megasol binder.
Made media and tested to find porosity, permeability and hardness of sample.
Performed coalescence experiments by positioning the filter medium in horizontal and vertical direction to air flow.
Performed coalescence experiments with and without drainage channel by positioning the filter medium in horizontal and vertical direction to air flow.
Compared the results in terms of coalescence efficiency, pressure drop and quality factor for the filters with and without drainage channels in horizontal and vertical orientation.
Performed coalescence experiment with filter medium equipped with three drainage channels at different angles in horizontal orientation and vertical orientation.
FUTURE WORK
Use nonwoven microglass and polypropylene fiber-mats as drainage channel.
Develop recipe for making composite filter media.
Test composite filter media to obtain the optimum drainage layer thickness
Develop model to predict pressure drop, filter efficiency and quality factor.
Compare experimental results with prediction.
Less entrainment
More drainage,
bigger drops drains faster
Reduced Pressure Drop
Increase in Quality Factor
VERTICAL FLOW