Design and operation of a pilot-scale pulse-jet baghouse

1. Aerosol Sci. Vol. 29. Suppl. I, pp. S107941080. 1998 0 1998 Published by Elsevier Science Ltd. All rights reserved Printed in Great Brirain 0021-8502/98 $19.00+ 0.00

DESIGN AND OPERATION

OF A PILOT-SCALE

PULSE-JET BAGHOUSE

C.-J. TSAI and H.-C. LU

Institute of Environmental Engineering, National Chiao Tung University, No. 75 Poai St., Hsin Chu, Taiwan.

KEYWORDS

Filtration; Baghouse; Fabric Filters; Air Pollution Control

Previous investigators (Humphries and Madden, 1983; Sievert and Lijffler , 1989) pointed out that a critical cleaning efficiency exists for different indices of cleaning intensity, such as peak pulse overpressure, average pulse overpressure inside the bag and the fabric acceleration.

If

the index of cleaning intensity exceeds the critical value, the cleaning efficiency improves only slightly resulting in an energy waste.

In this study, a pilot-scale pulse-jet baghouse was

tested for investigating the performances of bag filtration and bag cleaning to determine the filtration curves under different operating conditions and obtain the critical cleaning indices. The influence of various nozzle-venturi assemblies on the index of cleaning intensity was also investigated.

Two 1.5 meter long and 127 mm diameter fabric bag made by polyester with

acrylic coating were used for the test. The effective residual pressure loss is an index to evaluate the bag cleaning effect.

The

average and peak pulse overpressure and maximum absolute magnitude of fabric acceleration are used as indices of cleaning intensity.

Fig. 1 show the relationship between average pulse

over-pressure and effective residual pressure at point (2), which is at the middle of the bag. When the average pulse overpressure exceeds about 600 pa, the effective residual pressure stays nearly constant. ous literature.

This value is very close to the value of 400-500 Pa reported in previ-

This study has also found that the critical peak overpressure value of about

1200 Pa and the critical value of fabric acceleration/deceleration of about 30 g. Figure 2 shows the relationship between the energy consumption of pressure tank and average pulse overpressure.

For no venturi condition, small nozzle diameter consumes more

energy while achieving the same average pulse overpressure. s1079

For type 1 venturi, which is the

Abstracts

S1080

of the 5th lnternational

Aerosol

Conference

1998

commercial venturi, energy consumption to obtain the same average pulse over-pressure 6

for 8 mm and 13 mm is very close. venturi

condition,

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large nozzle diameter

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cause more air being discharged into the bag i

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2

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i

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resulting in a more effective pulse overpressure. When venturi is installed, larger noz-

However, since a venturi throat constrains

OO&

...‘..,“‘.‘..“... 400

0

d

typezventurl

o,”

I

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d,=ZO

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:

600

A@ Q

1200

1600

ual pressure loss and cleaning force indices.

Wthout venturi . -+-d”=8mm

-

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Fig. 1 Relationship between effective resid-

tive pulse overpressure appreciably. I

’

”

I.

*

I..

’

m 1 venturi -e-d”=8mm - Q- . d”=20

mm

4

6

energy consumption.

Fig. 2

type 1 venturi

average pulseoverpr-we.pa

nozzle diameter will not increase the effec-

0

q

0

the air flow into the bag, an increase of the

-

wtthoutventun

Q,

4%~@o~s 0

zle also causes larger pulse over-pressure.

(21

0

8

10

kJ

Relationship between average pulse overpressure and tank energy consumption. ACKNOWLEDGMENT

Authors are grateful to the financial support of the National Science Council under the grant NSC 8f5-22 1 l-E-009-009. REFERENCES Humphris, W. and Madden, J. J. (1983). Filtration and Separation 20,404. Sieve& J. and LGffler , F. (1989). Chem. Eng. Process, 26, 179-183.