AU6830674A - Filter - Google Patents

Description

I

S1.8 .4 L. 111 MICROCOPY RESOLUTION TESTCHART NATI0ONALOBUREAU OFSTANDARS -1963

Il~ OQ

(CONVENTION. By one or more persons and/or a Company.) orni4 5 ik>.

COMMONWEALTH CO04" LL is,3 PatentIs Act I LTWENT AR DOLL0

2 6 APR 1974 CONVENTION APPLICAT J MO A PAT iNT PATENT OFFICE

x 11 THE AIR PREHEATER C~hPANY, INO7, We Applicants, of WeJJlsville,......... a.1t,-d tLY A ddress)et State o Ne a.Y

United States of America.

2 Heie hereby apply for the grant of a Patent for an invention entitled:

.FABRIC.

bfassit

which is described in the accompanying complete specification. This application is a

(4 )3 Hereknsert Convention application and is based on the application numbered(3

.ap~asia d .355,.355 I4 tlniner dC,, for a patent or similar protection made in ni ed States of. America....... 1.97.3 .27.th.APril,..

address for service is Messrs. Ed -j- Our .PetAttorneys, C.untrie and Russell Street, Melbourne, Victoria, Australia.

DATED this 24th day of 19Th.

AIR. PREHEATER. COMPANY, .ING.-

AIt t I al by

Tim Com iSIONI:Ii OF PAIEN'rS.A

Ed, d Waters Sn. %feI'l e

(CONVENTION. Company.) rn8

COMMONWEALTH OF AUSTRALIA

Patents Act 1952-1962 -7 DECLARATION IN SUPPORT OF A CONVENTION 6 APPLICATION FOR A PATENT OR PATENT OF ADDITION

T support of the Convention Apiaonmade by Inr Th e Air

(hereinafter referred to as the applicant) for a Patent for an invention entitled:(,) FABRIC FILTER

Im EdonHamn

Amcerica-

:do solemnly and sincerely declare as follows:

1. 1 am authorised by the applicant for the patent

tomake this declaration on its behalf.

2. The basic application as defined by Section 141 of the Act was

l~2),iid onte. .mrli7 ddayy y il .1y n

ld F.Lil~ Michael Anderson

lr H.-i .(5).WillJiem Michael..Anderson, Hillside Lane,.. We lls)J.., 3

an d"1. New York, United States of America

is/zaxtihe actual inventor of the invention and the facts upon which the applicant

entitled to make the application are as follow:

The applicant is the assignee ofL.1he sajid Willi Mc o

by virtue of an assignment dated- April 24.,..AP.19.9..

the first application made in a Convention country in

respect of the invention the subject of the application.

DECLARED at KIA2 Uied t~netct St Q~.Aerica. Xe

don Harmon Luther To: i-ipCOMMSSIOER O PATNTS

EP- 5 32

Form COMMON'VEALTH Or AUSTRALIA

PATENTS ACT 19157-6

0 OIVI ELETFE SEOI A (ORIGINAL)

Class Int. Class Application Numnber: QA-_ I Lodged: 1L

Complete Specification Lodged: A NY

Published: ~C 0CW)3

:Priosity:

!Thted Ar-t k- "t

~oC 0 .4 "D

411l~e of Applicant TIME AIR PRTEHEATER COM?4i0Y, INC.*,

Address of Applicant: 7ELLSVILLE, ITEVW YORK, UIRITED STATES OF -AIIERICA.

7 ctual Inventor: 71illiam M. ANDERSOIT

*A44ess Ce-.vice: EDWD. WATERS SONS, 30 RUSSELL STPRrET, MELBOURNE, AUSTRALIA. 3000.

Complete Cpecification for the inventioe, entitled: "FABRIC FILTER" LSfA J

L26 APR 1974 PATV'Tr orj",e;1

The following statemetit is a full description of this invention, intcluding the best meIthod of performing it known tou:LS

BACKGROUI1D OP THE INUENTION

In filteringr apparatus of the bag filter type, dust

bearing gas to be cleaned is directed through pores of a fabric filter bag whereby the dirty gas on passing through

che porous material deposits suspended particulate matter on

the surface of the filter bag. Periodically each one of the

filter bags must be purged of the particulate material col-

lecting on the surface thereof to return the filter bags to

a clean condition whereby a high rate of filtering efficiency

may be resumed. After particulate matter is removed from one bag by

*e any one of various cleaning operations, it is presumed to fall by gravity to the bottom of the housing where it is collected

and ultimately removed. 404 Frequently however, particulate matter removed from

one bag becomes reentrained in the uifiltered gas stream and

is carried back to be filtered again by the same or a filter

bag adjacent thereto thus lowering the effectiveness of the

cleaning operation and increasing the time required for

o 20 complete filtration.

SUI,'j-'ATZ OF TEIIVENTION

This invention therefore provides a unique housing

o@ arrangement for a bag filterhouse whereby particulate matter

S".having been initially filtered from a dirty gas stream and

then removed from the filter is restrained from being re-

entrained in the dirty gas stream and being refiltered by the

same or adjacent filter bags.

Inasmuch as the dust carrying capacity of a dust

stream depends upon the velocity of the gas, this invention

provides a region adjacent each filter element wherein the velocity of a gas stream through a filter housing is reduced so that the dust particles are permitted to separate therefrom.

More particularly, since as the velocity of a gas

stream adjacent an imperforate wall approaches zero, this

invention provides for the strategic placement of imperforate

walls adjacent the filter elements to reduce the velocity of

the gas flow and thereby provide for an area having little

dust carrying capacity.

BRIEF DESCRIPTION OF THE DRAWING

These advantages will become more apparent from

the following description taken in conjunction with th3

accompanying drawings in which:

Figure 1 is a side elevation of a filter arrange-

ment involving the present invention,

Figure 2 is a vertical section as seen from line

2 2 of Figure 1,

Figure 3 is a perspective view of a bag filter

having independent cell-like compartments for each bag,

Figure 4 is a perspective view showing a modified

form of device having cylindrical compartments,

Figure 5 illustrates the principle utilized by

the flow retarding means during a filtering operation, and

Figure 6 illustrates the principle utilized by

the flow retarding means during a cleaning operation.

DESCRIPTION OF THE PREFERRED EBODIMENT In the drawing the numeral 10 indicates a housing which is formed with an inlet 12 for dust entrained gas and

an outlet 14 for gas which has been stripped of the entrained dust by passing through openings or pores in the rows of

filter bags 16 supported therebetween. The bags 16 each

3 e• depend from a collar 18 secured to tie underside of each aperture 20 in tube sheet 22 that separates the housing into inlet and ounet compartments 21 and 23. Imperforate sheets 24~ are affixed normal to the tube shoot 22 lying intermediate rows of depending filter bags to preclude fluid flow between rows of elements and provide an area of increased resistance that lies laterally adjacent each sheet and intermediate adjacent rows of filter bags.

A nozzle 28 is connected via passageway 30 to a sourec 32 of compressed air for cleaning. Wlhen a blast of

comressed air from the source is ejected into the open end

of cach filter bag it causes a momentary halt to the flow of dlust entrained gas through the bag, a slight flexure of the bag, and momentary shock effect upon the dust particles collected upon the outer surface of the bag. Thus the indep-

do!dust particles collecting on the bag are loosened and those agglomerated into a heavy "dust cake" will fall by gravity to hopper 33 at the bottom of the housing. -A substantial portion of the non-agglomerated dust particles

PO that have been deposited on the bag filter will be driven

by the blast of cleaning air from the surface of said bag to thc low velocity region adjacent the imperforate surface of i'late 24j. Upon reaching the low velocity region surrounding each surface, the particles entrained in the fluid will find

insufficient velocity to again become entrained ad will drop to the bottom of the housing where they may eventually be removed and disposed of in any predetermined manner.

In the preferred form of device shown in Figure 1, dust entrained air enters the inlet 12 and flows outward through the central passageway 15 between banks of collecting

a 4 tubes 16. The dust entrained air then turns laterally between the imperforate sheets and passes through the filter bags to deposit the dust on the outer surface thereof before it is exhausted through outlet 14 as substantially dust-free air in the manner shown by Figure When a collection of dust particles on the surface of the several bags retard flow therethrough, or in accordance with arypredetermined cycle of frequency, a olast of cleaning air from source 32 is ejected into the open ends of the filter bags from nozzles 28 in supply line 30 as controlled by valve 38. The filter bags momentarily flex, and the blast of air tends to drive the independent dust particles laterally.

The heavier particles immediately fall while those particles which are lighter move toward the sheets 24 to reach a low velocity region adjacent thereto where they too fall to the

collection hopper 33 lying at the bottom of the housing.

Under certain flow conditions it may be desirable

to extend the cell type walls 24 to comprise a full cell 42 that surrounds each bag filter element 16. A further variation may include a cylindrical wall 44 formed to surround

each filter element 16 in the manner shown by Fig. 4. These and other variations indicate that the device

could be extended to include various other shapes and designs of baffle sheet adjacent each filter element. It is to be understood therefore that the details of this disclosure are e a

described herein by way of illustration only and limits of

the invention are to be determined by the scope of the

annended claims.

e

.5 so

'2hce claims defining, the invention are as follows:

II Filter annaratus for removing entrained particulate from a carrier gas stream comprising a filter housing

1-vin-- inlet for gas to be filtered and an outlet for the

ehuto-,' clean gas therefrom, a tube sheet having a plurality

o2f mr.wcea, npertures there-in adapted to sepnarate the inlet from 46; o outlot, a pnorous filter element covering each aperture of

.~i1tube sheet, cleaning means for the filter elements

rnda-.ted to remove collected narticulate matter therefrom, and

Pii imperforate surfEioe intermediate said filter elements

er t'ot~ retard the flow of the carrier Ugas stream thereby

todcrea,,se the capacity of the carrier q-as to entrain

'rtcultematter thierein and to urevent fluid flowi between

'ornim filter elements whereby particulate matter removed from fl ilter relement is inrecluded from movinq; lateral. to a

fi~t'~r ol e'ncnt adjacent thereto.

Filter anpLratus for reoigentrained narticulote

t-~rfrom a carrier gas stream as defined in claim 1 w/herein

tO ilter elements comrise tubular means disnosed vertically "cr husng: with the-iu iperforate surface thereof lying

internc diaote the tubular means.

Filter appDaratus for rer.movixrZ entrained particula~te from a carrier 7as stream comprisin!g a housing- having

rin inlert for dust entrained -as and ain outlet for clean -,as,

ar.,,tuired tube sheet extendina across said housing-,

intorred "let and outlet openings to form inlet and

111tl1t rovws of filter bars in the inlet chnmber depending from the tube sheet and positioned to cover the

.omertures therein, cleaning means for the filter bags adapted

to remove collected particulate therefrom, a dust hopper at

the bottom of said housirng adapted to receive the dust from

s id filter bags, and an elongate surface intermediate rows

of filter bags adapted to provide a flow retarding means

intermediate adjacent rows of filter bags.

Filter apparatus for removing entrained particulate

mnatter from a carrier gas stream comprising a housing, a dust

h-on er subjacent said housing, an inlet fcr dust entrained

'ls, an outlet for clean gas, an apertured tube sheet

extending across said housing intermediate inlet and outlet

openings to separate the housing into inlet and outlet

chambers, a flow passageway extending across said housing

laterally from the inlet to direct the dust entrained gas

therethrough, rows of filter bags depending from said tube

sheet at the sides of said flow passageway into the space

between tubes adapted to direct the dust entrained gas between

rows of filter bags, cleaning means dapted to remove collected

dut particles from the outer surface of said filter bags,

nd ar imnerforate surface extending between rows of filter ee e

bn-s to provide a flow resistin,; means that affords an area

of restricted flow adjacent opposite sides of said filter bags

.an thus decreases the capacity of the carrier gas to entrain

narticulate matter therein.

5. Filter ai~paratus for removing entrained narticulate

matter from a carrier gas stream comprising a filter housing

havin- an inlet for gas to be filtered and an outlet for the

e -7- w" cxhlust of clean gas therefrom, an apertured tube sheet ctendin across said housing intermediate the inlet and outlet sepnrating said housing into inlet and outlet chambers, a tubular f -r bag having an open end secured to the tube shnit orour_u each aperture and a closed end depending there- from into the inlet chamber, cleaning means for the filter bar comprising a nozzle directed into the open end of each filter bag to exhaust cleaning fluid thereto, a source of cleaning fluid, duct means connecting said source of cleaning fluid to nozzle, and an imperforate surface intermediate said filter bags adapted to isolate each filter bag from laterally adjacent bags whereby collected particulate matter removed from the surface of one filter bag is precluded from becoming entrained in carrier gas flowing to the filter bags adjacent thereto and each filter bag is surrounded by a region that affords increased resistance to the flow of gas.

6. F_ -r apparatus for removing entrained particulate

natter from a carrier gas stream as defined in claim 5 wherein

i-t inmerforate surface comprises a honey-comb-like structure

with r-ctangular walls.

S7. Filter apparatus for removing entrained particulate

matter from a carrier gas as defined in claim 5 wherein the

iimnerforatc surface that surrounds each tubular filter bag

comrises a cylindrical container substantially concentric

thnrewith.

*e a 8

8. Filter anna),ratus for removing entrained particulate

matter from a carrier gas stream substantially as hereinbefore described with ref'. ence to and as illustrated by the accompanying drawings.

DATED this 7th day of FEBRUARY 1974~.

THE AIR PREHEDATER CCMPiUTVY, _I.NC

EDW-D. VIATERS ,OlqS, Patent Attorneyb, Russell Street,, MELBOURNE, IM: GR AUSTRA'L.IA.

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