AIR POLLUTION CONTROL TECHNOLOGY (CEB 30403)
TITLE OF EXPERIMENT
PARTICULA PARTICULATE TE EMISSION CONTROL BY DOUBLE CYCLONE CYC LONE SYSTEM
NAME : THEYVAN A/L GANESAN
ID
: 5520224
LECTURER : DR! DR ! AMELIA
DATE DATE OF EXPERIMENT : " MARCH 205
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!0 INTRODUCTION
This experiment was conducted to study the effect of cyclone body diameter upon collection efficiency. The cyclonic separator is an important and popular type of dust-removal equipment. In this experiment 50 gram of kaolin was used as sample to study the particulate collection efficiency of double cyclone system.
cyclone collector can be defined as a structure without moving parts in which the velocity of an inlet gas stream is transformed into a confined vortex from which centrifugal forces tend to drive the suspended particles to the wall of of the cyclone body. It consists of vertically placed cylinders which has an inverted cone attached to its base. The particulate-laden gas stream enters tangentially at the inlet point into the cylinder. The outlet pipe for the purified gas is a central cylindrical opening at the top. The dust particulates are collected at the bottom in a storage hopper. The gas path generally follows a dou ble vortex !Tse "ung#$0%$&. The gas is first allowed to flow through a light circular spiral which produces centrifugal force on the suspended particles which in turn are forced to move upwards at the central portion of the cyclone. 'ecause of inertia# the dust particles tend to settle on the surface of the cyclone wall# from where they are collected in receivers !(harma#$00)&.
*igure %.0 + ,yclone (eparator !(ource + Tse "ung# $0%$ "andbook of nvironment and aste /anagement# pp.%&
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The collection efficiency of cyclones varies as a function of particle si1e and cyclone design. ,yclones are generally si1ed from the diameter of the cylinder !/udakavi#$0%0&. ,yclone efficiency generally increases with particle si1e and2or density# inlet duct velocity# cyclone body length# number of gas revolutions in the cyclone# ration of cyclone body diameter to gas exit diameter# dust loading# and smoothness of the cyclone inner wall. ,yclone efficiency will decrease with increases in gas velocity# body diameter# gas exit diameter# gas inlet duct area# and gas density. common factor contributing to decreased control efficiencies in cyclones is leakage of air into the dust outlet !,heremisinoff#$00$&.
3nder ideal operating conditions# the smaller diameter cyclone system can attain 40 collection efficiency. The larger diameter cyclone systems are usually free of plugging# and can achieve efficiencies up to about )0 . 6ery large diameter cyclone untis are rarely used because of their relatively low collection efficiency !rthur#%7))&.
There are three important operating problems associated with cyclones. They are erosion# corrosion# and material build-up. ,yclones consists of some advantages. It have low initial cost# low pressure drop# has no moving parts# low maintenance requirements# and so on. s for disadvantages it have low collection efficiency for particles below 5-%0 in diameter# deteriorate due to abrasive and decreasing dispersoid concentrations in the gas stream (Tse "ung# $0%$&.
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2!0 OB#ECTIVE
This experiment was conducted to achieve the following ob8ectives +
To study the effect of cyclone body diameter upon collection efficiency. To study the operating principle of double cyclone system. To study the ability of double cyclone system in removing pollutants.
3!0 METHODOLOGY
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%
The experiment was prepared for $00 mm cyclone operation.
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The empty feed container and dust hopper was weighed separately.
50g of kaolin was weighed and poured slowly into the feed container.
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9
The air pump was connected to the feed container with the tubing provided and the needle valve was initially closed.
5
The feed container was attached to the holder and ad8usted so that the outlet of feed container is 8ust inside the inlet piping of cyclone.
: )
;ext# the outlet dust filter was cleaned. The /ain (witch was switched <; and the (T=T button was pushed to run the air blower.
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4
The computer was switched <; !it directly launched the >( software& and then the ?@=I/;T button was clicked and ?@=I/;T l was
chosen. 7 %0 %% %$ % %9
%5 %:
The air pump was switched <; and the needle valve was opened slowly until boiling phenomena was observed. The stopwatch was started simultaneously. The =,<=> button was clicked to record the airflow rates and pressure drop. The experiment ran for 0 min The air blower was switched <** after the experiment was completed. The feed container was detached and the dust hopper and them was weighed separately.
The collection efficiency of the cyclone was determined by key in the weight of sample loaded and collected. The experiment was repeated with the %00mm body diameter cyclone.
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4!0 DATA - RESULTS T.% !0 : =eadings of several parameters according to diameter of cyclone
ir flow rate# A !m 2h& Inlet velocity# vB !m2s& @ressure >rop !in water& Initial weight of sample in feed container# ,I !g& *inal weight of sample in feed container# ,* !g& eight of sample collected in dust hopper# " !g& ,ollection efficiency# C !&
20011 $4.:$ $.%5 0.04$ 50 90 45.%%
0011 $:.0: %.7: 0.0$4 50 $ 9: 75.4
here# ,ollection efficiency# C D " 2 !,I- ,*& x %00
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5!0 DISCUSSION
This experiment was performed to study the effect of cyclone body diameter upon collection efficiency. There are two different type of cyclone body diameter to produce two different flowrates. ,yclone body diameter of $00 mm and %00 mm was tested to study the ob8ective of the experiment where it was tested one after another.
>uring the experiment# 50 g of kaolin was used as sample to test for cyclone body diameter efficiency. s for first run# the cyclone body diameter of $00 mm was tested. ccording to the data collected in Table %.0# the collection efficiency obtained for $00 mm cyclone diameter was 45.%% . ,ollection efficiency of second run with %00 mm cyclone body was 75.4 . The weight of sample collected in dust hopper for cyclone diameter $00 mm and %00 mm was 90 g and 9: g respectively. *urthermore# the air flow rate# A !m2h& recorded for both $00 mm and %00 mm cyclone diameter was $4.:$ m2h and $:.0: m2h respectively.
*rom the data obtained through this experiment it obiviously reveals that the collection efficiency of cyclone diameter of %00 mm is higher than the $00 mm cyclone diameter. hile# the flow rate A !m2h&# inlet velocity v !m2s&# and pressure drop !in water & of $00 mm cyclone diameter is higher than the %00 mm cyclone diameter. ,heremisinoff# $00$ said that cyclone efficiency will decrease with increases in gas velocity# body diameter# gas exit diameter# gas inlet duct area# and gas density. "ence# the experimental values obtained from this experiment is actually obey the above mentioned theoretical statement where as in this experiment# the higher the flow rate A !m2h&# inlet velocity v !m2s&# and pressure drop !in water &# the lower the collection efficiency. >uring low flow rate and low inlet velocity# more particulate matter !kaolin& able to carry via the cyclone body. (o# more dust can be collected.
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The collection efficiency of double cyclone system can be relate through an expression of centrifugal force +
* D E pd pv$ p
= here# E p D particle density# lb 2 ft !kg2m& d p D particle diameter# inches !Fm& v p D particle tangential velocity# ft2s !m2s& r D radius of the circular path# ft !m&
The larger the density E p# the greater the force# *. The larger particles d p # are more easily to be collected. The force also increase when the radius of the circular path# r reduced. This is why smaller cyclones are more efficient for collection of smaller si1ed particles like kaolin dust in this experiment.
The pressure drop of large diameter cyclone body may be due to some factors. It loss due to expansion of gas when it enters the cyclone chamber. Goss as kinetic energy of rotation in the cyclone chamber. Goss due to wall friction in the cyclone chamber. ny additional friction losses in the exit duct# resulting from the swirling flow above and beyond those incurred by straight flow. ny regain of the rotational kinetic energy as pressure energy.
venthough# the double cyclone system have higher collection efficiency# it have both pros and cons. s for advantage# it have little maintenance# simple construction# and does not have moving components. hile the disadvantages is it can create noise# unable to handle sticky or tacky materials# low output for low particle diameter# and high pressure drop !0.5 - $.5 k@a&.
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!0 CONCLUSION - RECOMMENDATION
This experiment was conducted to study the effect of cyclone body diameter upon collection efficiency. Two different diameter of cyclone ! $00 mm and %00 mm & was analysed with kaolin ! 50 g & as sample. The data and result collected reveals that the collection efficiency of double cyclone system for large cyclone diameter which is 45.%% is smaller than the small cyclone diameter 75.4 . It is due to the some factors# such as flow rate A !m 2h&# inlet velocity v !m2s&# and pressure drop !in water&. (maller cyclones are more efficient for collection of smaller si1ed particles like kaolin dust in this experiment compared to the larger cyclones.
s for recommendation# it is suggested that the cyclone body must have to clean properly to avoid any dusts stick on it before begin the experiment. /ust have to ensure that the dust hopper connected properly to the system because sometime it may fall down from itHs original place where it interrupt the process of dust collection. =egular inspection have to be performed to the system so that a stable and accurate flow rate# velocity# and pressure drop can be maintained throughout the whole experiment.
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!0 REFERENCE
%. Tse "ung#!$0%$&# Handbook of Environment and Waste Management # orld (cientific @ublishing ,o. @te. Gtd. $. ,heremisinoff# ;.@. !$00$&# Handbook of Air Pollution Prevention and Control # lseveir (cience !3(&.
. (harma# '..!$00)&# Environmental Chemistry#rishna @rakashan /edia !@& Gtd. 9. rthur# ,.(.!%7))&# Engineering control of Air Pollution#cademic @ress Inc. 5. /udakavi# J.=.!$0%0&# Principles and Practices of Air Pollution Control and Analysis#International @ublishing "ouse @vt Gtd.
!0 APPENDIX
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,ollection efficiency of double cyclone system was calculated using the formula below+
,ollection efficiency# C D " 2 !,I- ,*& x %00
200 11
,ollection efficiency# C D 90 2 !50- & x %00 D 45.%%
00 11
,ollection efficiency# C D 9: 2 !50- $& x %00 D 75.4
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*igure $.0 + =aw data of readings of several parameters according to diameter of c yclone
*igure .0 + =aw data for xperiment % !$00 mm&
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*igure 9.0 + =aw data for xperiment $ !%00 mm&
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