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ENERGETIC EVALUATIONAND ASSESSMENT BY FILTRATION SPECIFIC PARAMETERS
OF CLEANABLE FILTER MEDIA USING STANDARDIZED FILTER TEST RIGS
Dipl.-Ing. Dr. Thomas Laminger
Vienna University of Technology
Institute of Chemical Engineering
Mechanical Process Engineering and Clean Air Technology
Institute of Chemical EngineeringInstitut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften
Vienna University of TechnologyTechnische Universität Wien
Content
2
• Introduction
Criteria for choosing filter media
Standards for evaluation of filtration and energy related parameters of filter media
• Definition of an energy consumption value of a filter test usinga standardized filter test rig (ISO 11057)
• Detailed experimental results of an exemplary filter test including the energy consumption value
• Comparison of different filter media with regard to the energy consumption value and the mean clean gas concentration
• Summary
• Analogies to other filter systems
Institute of Chemical EngineeringInstitut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften
Vienna University of TechnologyTechnische Universität Wien
Introduction
Standards for evaluation of filter media parameters of dust separation systems:
• Filtration specific parameters:
Depth filters: e.g. DIN EN 779
HEPA filter: e.g. DIN EN 1822
Cleanable dust filters: e.g. VDI 3926, EN ISO 11057…
• Energy related parameters:
EUROVENT 4/11 for depth filters (tested according to DIN EN 779)
Criteria for choosing a filter system:• Maximum permissible value: clean gas concentration value…• Operation conditions: dust properties, temperature…• Costs:
Fixed costs (investment costs) Operation costs (constantly or repeatedly incurred cost)
Institute of Chemical EngineeringInstitut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften
Vienna University of TechnologyTechnische Universität Wien
Introduction
𝑊 =𝑞. ∆𝑝. ℎ
ƞ. 1000
W….Annual Energy consumption [kWh]q….....Volume flow rate (0.944 m³/s)∆𝑝…..Averaged Pressure drop in EN 779 test [Pa]h….....Operation time (6000 h)Ƞ…….Fan efficiency (0.9)
EUROVENT 4/11 for depth filters (tested according to DIN EN 779)
“ENERGY EFFICIENCY CLASSIFICATION OF AIR FILTERS
FOR GENERAL VENTILATION PURPOSES”
This guideline define a method of air filter classification with regard to energy-efficient operation
Institute of Chemical EngineeringInstitut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften
Vienna University of TechnologyTechnische Universität Wien
Objective
5
To evaluate and compare different cleanable dust filter media beside filtration specific parameters (e.g. residual pressure drop…) an evaluation with regard to the energy demand is also desirable.
Objective:
To develop a value for the total energy consumption for a ISO 11057 test rig to compare different filter media in terms of energy consumption together with their penetrated amount of particles.
Institute of Chemical EngineeringInstitut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften
Vienna University of TechnologyTechnische Universität Wien
Energy consumption of a filter test using a filter test rig (ISO 11057)
6
Power consumption of n filtration cycles Ptot,n [W]
• Power consumption of the fan Pfan,n
• Power consumption for the needed
compressed air of the pulse-jet cleaning Pcleaning,n
Test filterAbsolut filter
Pressurized air tank
Ambient air
Dust disperser
Pressured
air
Fan
Scattered light
particle sensor
Ptot,n = Pfan,n + Pcleaning,n
Pfan,n = ∆ pfilter,n. V
P cleaning,n =∆ptank. Vtank. n
i=1n tcycle,i
∆ pfilter,n…. Mean pressure drop of n
filtration cycles [Pa] V……………. Air flow rate [m³/s]∆ptank …….Air tank pressure (before and
after cleaning) [Pa]Vtank……….Volume of the air tank [m³]tcycle,i…….. Cycle duration of the filtration
cycle i [s]n……………..Number of filtration cycle [-]
Institute of Chemical EngineeringInstitut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften
Vienna University of TechnologyTechnische Universität Wien
Energy consumption of a filter test using a filter test rig (ISO 11057)
7
Volume-related total energy consumption of
n filtration cycles EV,tot,n [Wh/m³] 𝐸𝑉,𝑡𝑜𝑡,𝑛 =𝐸𝑡𝑜𝑡,𝑛
𝑉𝑡𝑜𝑡,𝑛=
𝑃𝑡𝑜𝑡,𝑛 .𝑡𝑡𝑜𝑡,𝑛
𝑉𝑡𝑜𝑡,𝑛=
𝑃𝑡𝑜𝑡,𝑛 𝑉
𝐸𝑉,𝑡𝑜𝑡,𝑛 = ∆ 𝑝𝑓𝑖𝑙𝑡𝑒𝑟,𝑛 +∆𝑝𝑡𝑎𝑛𝑘.𝑉𝑡𝑎𝑛𝑘.𝑛
𝑉. 𝑖=1𝑛 𝑡𝑐𝑦𝑐𝑙𝑒,𝑖
l
Etot,n………. Volume-related total energy consumption of n filtration cycles [Wh/m³]
Vtot,n…….… Total air volume throughput from the beginning of a filter test to the end of the filtration cycle n [m³]
ttot,n……… Total duration from the beginning of a filter test to the end of the filtration cycle n [s]
∆ pfilter,n…. Mean pressure drop of n
filtration cycles [Pa] V……………. Air flow rate [m³/s]∆ptank ……Air tank pressure (before and
after cleaning) [Pa]Vtank…… . .Volume of the air tanktcycle,i…….. Cycle duration of the filtration
cycle i [s]n……………..Number of filtration cycle [-]
Ws
m3 =J
m3 =Nm
m3 =N
m2 = Pa l
Test filterAbsolut filter
Pressurized air tank
Ambient air
Dust disperser
Pressured
air
Fan
Scattered light
particle sensor
Institute of Chemical EngineeringInstitut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften
Vienna University of TechnologyTechnische Universität Wien
Mean clean gas concentration
Mean clean gas concentration of
n filtration cycles cclean,n [mg/m³]
Using a scattered light particle sensor with continuous single
particle detection in order to determine the mean clean gas
concentration
𝑐𝑐𝑙𝑒𝑎𝑛,𝑛 =1
𝑖=1𝑛 𝑡𝑐𝑦𝑐𝑙𝑒,𝑖
. 𝑖=1
𝑛
𝑐𝑐𝑙𝑒𝑎𝑛,𝑖 . 𝑡𝑐𝑦𝑐𝑙𝑒,𝑖
cclean,i…… Mean clean gas concentration of
the filtration cycle i [P/cm³] or [mg/m³]
tcycle,i….. Cycle duration of the filtration
cylce i [s]n…………….Number of filtration cylces [-]
Test filterAbsolut filter
Pressurized air tank
Ambient air
Dust disperser
Pressured
air
Fan
Scattered light
particle sensor
Institute of Chemical EngineeringInstitut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften
Vienna University of TechnologyTechnische Universität Wien
Comparison of different filter media
Filter face velocity m³/(m²h) 120
Dust concentration g/m³ 5
Test dustSasol Pural NF
d10,3=1.2µm, d50,3=4.5µm, d90,3=21.0µm
Pressure drop prior to pulse-jet cleaning
Pa 1000
Tank pressure MPa 0,5
Valve opening time ms 60
Number of fitration cycles [-] 30
Effective filter area m² 0.0177
Test conditions
Comparison of different filter media
using two single parameters:
• Ev,tot,n [Wh/m³]
• cclean,n [mg/m³]
for n=30 of the first 30 filtration cycles of a new filter medium
for n=30 of the 30 filtration cycles after artificial aging
1. PhaseOperating with filter in new condition
30 pressure controlled cycles
2. Phase Artificial aging2500 time controlled
cycles (20s)
3. Phase Stabilization10 pressure controlled
cycles
4. PhaseOperating with filter in aged condition
30 pressure controlled cycles
Test phases (according to the ISO 11057)
Institute of Chemical EngineeringInstitut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften
Vienna University of TechnologyTechnische Universität Wien
Exemplary filter medium: Needle felt (PI); 1st test phase (new filter medium)
Development of the pressure drop and
clean gas concentration over the time
Filtration cycle duration and residual pressure
drop over the number of filtration cycles
Institute of Chemical EngineeringInstitut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften
Vienna University of TechnologyTechnische Universität Wien
0
4
8
12
16
0,00
0,10
0,20
0,30
0,40
0 10 20 30
Me
an cle
an gas co
nce
ntratio
n
cclean
,n[m
g/m³]
Vo
lum
e-r
ela
ted
to
tal e
ne
rgy
con
sum
pti
on
E V
,to
t,n
[Wh
/m³]
Number of filtration cycles [-]
Needle felt (PI)
Volume-related total energyconsumption
Mean clean gas concentration
Exemplary filter medium: Needle felt (PI); 1st test phase (new filter medium)
Volume-related total energy consumption Ev,tot,n and
mean clean gas concentration cclean,mean,n over the number of filtration cycles
𝐸𝑉,𝑡𝑜𝑡,𝑛 = ∆ 𝑝𝑓𝑖𝑙𝑡𝑒𝑟,𝑛 +∆𝑝𝑡𝑎𝑛𝑘.𝑉𝑡𝑎𝑛𝑘.𝑛
𝑉. 𝑖=1𝑛 𝑡𝑧𝑦𝑘𝑙𝑢𝑠,𝑖
l 𝑐𝑐𝑙𝑒𝑎𝑛,𝑛 =1
𝑖=1𝑛 𝑡𝑐𝑦𝑐𝑙𝑒,𝑖
. 𝑖=1
𝑛
𝑐𝑐𝑙𝑒𝑎𝑛,𝑖 . 𝑡𝑐𝑦𝑐𝑙𝑒,𝑖
Institute of Chemical EngineeringInstitut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften
Vienna University of TechnologyTechnische Universität Wien
Exemplary filter medium: Needle felt (PI)
Development of the pressure drop and
clean gas concentration over the time
2
34
1
Institute of Chemical EngineeringInstitut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften
Vienna University of TechnologyTechnische Universität Wien
Exemplary filter medium: Needle felt (PI)
Filtration cycle duration and residual pressure
drop over the number of filtration cycles
Operating with filter in new
condition
Operating with filter in aged
condition
Institute of Chemical EngineeringInstitut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften
Vienna University of TechnologyTechnische Universität Wien
Exemplary filter medium: Needle felt (PI)
Volume-related total energy consumption Ev,tot,n and
mean clean gas concentration cclean,mean,n over the number of filtration cycles
Operating with filter in new
condition
Operating with filter in aged
condition
Institute of Chemical EngineeringInstitut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften
Vienna University of TechnologyTechnische Universität Wien
Comparison of different filter media
𝐸𝑉,𝑡𝑜𝑡,30 ↗
cclean,30 ↘
Volume-related total energy consumption Ev,tot,n and
mean clean gas concentration cclean,n of 30 filtration cycles
(1st test phase – operating with filter in new condition)
Exemplary criterion:
Mean clean gas
concentration <1 mg/m³
FM 4 with lowest EV,tot,30
Institute of Chemical EngineeringInstitut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften
Vienna University of TechnologyTechnische Universität Wien
Analogies to other filter systems
• Filter systems can vary concerning their different mechanism of regeneration, operation principle. By variation of one single parameter (e.g. filter medium, regeneration time, regeneration intensity…) the filtration behaviour and the energy consumption is influenced and both gives an unique pair of indicator.
• An energy consumption value should therefore include the main indicators for operation (e.g. pressure drop, energy for regeneration, blower or pump energy demand… ) which are specific for a filter system.
• Notice: The usage of the energy consumption value and/or filtration parameters which are resulted from laboratory tests, has to be done very carefully as many further parameters have to be considered.
Institute of Chemical EngineeringInstitut für Verfahrenstechnik, Umwelttechnik und Technische Biowissenschaften
Vienna University of TechnologyTechnische Universität Wien
Summary
• A volume–related energy consumption value (Ev,tot,n) was developed to have one single parameter to compare different cleanable dust filter media regarding to their energy consumption. This volume-related energy consumption value adds the needed average energy for the fan and the average energy for the jet-pulse cleaning at a filter test rig.
• Further the mean clean gas concentration (cclean,n) was used to determine the particle penetration throughput the filter media in order to characterize the filtration efficiency of a filter medium.
• Different filter media were tested at a modified filter test rig (according to ISO 11057) with a scattered light sensor for the measurement of the clean gas concentration, in order to determine the values Ev,tot,n and cclean,n.
It was shown that using both values can be used for an easy selection of an adequate filter medium, which has been tested at the test rig.
Generally, a lower clean gas concentration cclean,n can only be reached with a higher volume–related energy consumption value (Ev,tot,n).
17
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