US3409131A - Inertial type pneumatic separator - Google Patents

Description

A. A. PETERSEN ET AL INERTIAL TYPE PNEUMATIC SEPARATQR 4 Sheets-Sheet 1 4/ $54 3 4 Z 222 22 s a V, P 6 mg 54! 7 fl 2 TTB 22 1 m .1 n 11 m mam d w w m PA 5 Mu Q Kw M mo m m u o u 0 "RIM m Z F I L m- I L D 2 {I i Iil lW/w Em Ev 4 r M 2 T m n Q i m af/ QTTOENEY Nov. 5, 1968 A. A. PETERSEN ET INERTIAL TYPE PNEUMATIC SEPARATOR 4 Sheets-Sheet 2 Filed Nov. 24, 1964 ooo coo 5 2 253 ES w INVENTORS QLFEED ARNOLD PETERSEN LLHQM GIBBS Dnvw WI BY a, M

HTTOR/Vf? Nov. 5, 1968 'A. A. PETERSEN ET AL 3,409,131

INERTIAL TYPE PNEUMATIC SEPARATOR Filed NOV. 24, 1964 4 Sheets-Sheet 3 Ti::. '2. 4a

' INVENTORS ALFRED ARNOLD PETERSEN Dnvm WILLIAM GIBBS HTTOENGY NOV. 5, 1968 A, E E ET AL 3,409,131

INERTIAL TYPE PNEUMATIC SEPARATOR Filed Nov. 24, 1964 4 She ts-Shet 4 5 .1m. Ti .11 7Z3- 5 3 1 5% 7/ INVENTORS ALFRED ARNOLD PETERSEN DgQ/ID WILLIAM GIBBS ma rm United States Patent 3,409,131 INERTIAL TYPE PNEUMATIC SEPARATO Alfred Arnold Petersen, Byram, Conn., and David William Gibbs, Port Chester, N.Y., assignors, by mesne assignments, to Universal Oil Products Company, Des Plaines, Ill., a corporation of Delaware Filed Nov. 24, 1964, Ser. No. 413,520

' Claims. (Cl. 209-143) ABSTRACT OF THE DISCLOSURE A particle classifier for separating from a gas in which particles of different inertia relative to their superficial areas are separated and classified. The classifier is a container divided into a plenum chamber and particlereceiving chamber. The receiving chamber is arranged in the gas flow direction to receive by selective separation, first the fines after passage through centrifugal separating tubes; and, second downstream thereof, the relatively heavy particles by passage directly into a separate compartment or after passage through a second set of centrifugal separating tubes then into the separate compartrnent. The centrifugal separating tubes receive particleladen gas from the plenum chamber and pass cleaned gas to the atmosphere and separated particles into the receiving chamber. A deflector located up-stream of the particle receiving compartment deflects the gas stream portion carrying relatively heavy particles past the fines compartment. A second deflector effects a sharp reversal of the gas stream portion carrying the relatively lighter particles (fines) to flow into the fines receiving compartment.

Our present invention relates to a dynamic centrifugal particle classifier and to a method of classification in which particles of different inertias relative to their superficial areas are classified in suspension in a gas stream and are separately recovered. The gas may be of any medium in the gaseous phase, such as air, natural or industrial gas or vapor.

Gasses' frequently carry in suspension particles of different inertia, in which the particles having inertias within a specific range are of interest because they have valuesnot possessed by particles in another range of inertias. Classification of the suspended particles is, therefore, desirable. For example, in burning powdered coal or other solid fuels in suspension in air, the particles are or may be of unequal size and consequently the finer particles burn more quickly than the larger particles which may not burn completely and, therefore, retain a part of their fuel values. The particles or ash remaining after combustion have been generally separated from the exhaust gases by means of multitube centrifugal separators. The material t-hus separated in the centrifugal tubes has not been classified and, therefore, contains a mixture of particles both completely and partially burned. It is, therefore, impractical to burn any of the unburned fuel in these particles without recycling all material whereas, if classified, only the portion having sufficient fuel values could be recycled (for further burning. In other industrial processes, also, particles having different inertias because of different densities as well as because of different sizes or dimensions are formed in suspension in a gas. Classification of these particles may be required.

In our invention suspended particles are classified and collected according to their inertias relative to the super-ficial areas of the particles.

In the method and apparatus of our invention the gas stream, or a portion of it, in which the particles are carried is turned sharply, carrying with it the particles of lesser inertia relative to their superficial areas while the particles of larger inertia relative to their superficial areas continue generally in their initial direction or movement out of this turned stream which may be a portion of the total gas stream. The particles are thereby classified into streams carrying particles of different sizes or densities.

The collection of the classified suspended particles from the gas stream in which they are carried may be accomplished in various manners and by various means; Thus the sharply turned gas stream or portion thereof may be passed through multi-tube centrifugal separators while the particles that have passed out of the air stream are separated by a separate means. Or, the particles of greater relative inertia may be separated from particles of lesser relative inertia carried in a mixture and the former recycled. Where conditions permit or make the separation of the particles of lesser inertia unnecessary, only the particles of greater inertia relative to their superficial area need be collected.

The various features of our invention are illustrated, by way of example, in the accompanying drawings in which:

FIG. 1 is a vertical section on line 11 of FIG. 2;

FIG. 2 is a vertical section at right angles to the section of FIG. 1 on line 22 of FIG. 1;

FIG. 3 is a horizontal sectional view taken on line 3-3 of FIG. 1 of a portion of the separator;

FIG. 4 is a vertical section on line 44 of FIG. 5 showing a modification;

FIG. 5 is a vertical section on line 5-5 of FIG. 4;

FIG. 6 is a horizontal sectional view taken on line 6-6 of FIG. 4 of a portion of the separator of FIG. 4;

FIG. 7 is a vertical section through another modification of the invention;

FIG. 8 is a horizontal sectional view taken on line 88 of FIG. 7 of a portion of the separator of FIG. 7;

FIG. 9 is a vertical section similar to the section of FIG. 1 of still further modification of the invention;

FIG. 10 is a vertical section on line 10-10 of FIG. 11 illustrating another modification;

. FIG. 11 is a section on line 1111 of FIG. 10;

FIG. 12 is a horizontal section taken on line 12-12 of FIG. 10 of a portion of the separator shown in FIGS. 10 and 11;

FIG. 13 is a vertical section similar to the section of FIG. 1 of a still further modification of the invention; and

FIG. 14 is a plan of a portion of the separator shown in FIG. 13.

Referring to the embodiment shown in FIGS. 1, 2 and 3, the separating apparatus is contained in container 15 which is divided into two particle- collecting compartments 16 and 17 by means of a partition 18. The particlecollecting compartment 16 delivers into a collecting hopper 19, while the particles separated in compartment 17 deliver into a hopper 20. The compartment has a horizontal tube sheet 21 for both compartments 16 and 17 spaced above the hoppers 19 and 20 and carrying centrifugal separator tubes 22. Above the tube sheet 21 are pockets 23 spaced as shown in FIG. 2 diverging at their lower portions and having bottom tube sheets 24 with openended off-take pipes 25 extending axially into respective centrifugal separator tubes 22. The upper ends of the several pockets 23 open to exhaust the cleaned gas to the atmosphere through an opening 26 as shown particularly in FIGS. 2 and 3, or by a conduit leading to a stack, not shown. The front ends of the pockets 23 are rounded as shown at 27, FIG. 3, to avoid turbulence in the gas passing to the centrifugal separator tubes.

The container 15 is closed by a deck 28 sloping downwardly from the front, or left-hand part of the compartment, as shown in FIG. 1, to the rear or opposite end, and the openings 26 of the pockets 23 open through this deck. Gas is admitted to the upper part of the container in the direction shown by the arrow in FIG. -1 through an inlet 29 and passes into spaces 30 between the pockets 23 and the side walls of the container and thence flows downwardly into a space 31 below the lower ends 24 of the pockets. Thence the gases flow sidewise into the upper ends of the centrifugal tubes 22. Particles separated in the centrifugal tubes 22 drop into the hoppers 19. and 20 respectively while the cleaned gases pass upwardly through the off-take pipes into the pockets 26 and thence to ex-' haust.

According to the present invention deflectors 32 are mounted in the inlet 29 each being hinged at its front edge so that it may be swung vertically through an are indicated by the broken line 33. This tends to give the entering air or gas a slightly upward deflection. Mounted between the several pockets 23 above the compartment 16 are a number of deflectors 34 pivoted at their front edges so that they may be positioned at adjusted angles to the horizontal throughout the arcs indicated in broken lines at 35. As the particle laden gases enter the container between the pockets 23 they are first deflected upwardly to a slight extent by the deflectors 32 so as to direct any particles adjacent them in an upward direction. Thence as the gases pass above the spaces between the pockets above the compartment 16 a portion of the gases passes downwardly through the spaces between the pockets 23 to the space 31. Particles of a small size or of a low inertia pass into the spaces between the pockets 23 and thence to the spaces 31 into the centrifugal separators 22 while particles of greater inertia relative to their superficial area are carried by their momentum successively over the deflectors 34 to the spaces between the rear portions of the pockets 23, whence they pass downwardly between these portions of the pockets to the spaces above the centrifugal separators 22 in the compartment 17. Here the coarser particles, or those of greater inertia relative to their superficial area, drop into the hoppers 20 while the clean gases pass upwardly through the off-take 25 and the pockets 23 to exhaust. In this way the particles are classified before they pass to their respective centrifugal separators, the lighter particles passing into the hopper 19 and the coarser or denser particles passing into the hopper 20.

It will be understood that a smaller particle will have a lower inertia relative to its superficial area and that, therefore, the effect of the superficial area will overbalance the effect of inertia so that these particles may pass-downwardly with the gas in the deflectors 34, whereas particles having a greater inertia relative to their superficial area, either because of greater density or greater size, will because of the greater relative inertia pass above the deflectors 34 into the space above the compartment 17. These particles of greater inertia may be deflected successively upwardly by the deflectors 34. Classification may, therefore, be made on the basis of particle size or density, or both, depending upon the material being treated.

In the modification shown in FIGS. 4, and 6, the elements -22, 25, 28, 29 and 32 are the same as those in the embodiment shown in FIGS. 1, 2 and 3.

In the embodiment shown in FIGS. 4, 5 and 6, the pockets 23 are omitted and the off-take pipes 25 pass directly through the deck 28, either to atmosphere or to a stack. The centrifugal tubes and the off-take pipes 25 are arranged in parallel rows extending from the front to the rear of the space above the tube sheet 21 and in front of each row is a shield 36 extending vertically in front of the first off-take pipe of each row of centrifugal tubes and pipes and rounded at its forward end 37. The purpose of this is to direct the oncoming gas through channels 38 to the spaces between the first of the centrifugal separators and off-take pipes. Gas then passes through the passages .38 and above the deflectors 32 to the spaces between the off-take pipes 25 and over the deflectors 34 which are arranged in the same manner as those in FIGS. l-3, except that they extend entirely transversely of the container, as indicated in FIG. 5, between successive off-take pipes. The action is similar to that shown in the modification in FIGS. 1-3, the gas being deflected upwardly by the deflectors 32 and 34 to cause the particles of greater inertia to ride over the deflectors 34 while gas, containingthe lighter particles is drawn downwardly between these deflectors to be separated by the centrifugal tubes 22 above the hopper 19, while the remaining gas containing the particles of greater inertia pass to the centrifugal separators above the hopper 20. 4

FIGS. 7 and 8 illustrate a modification in which the centrifugal tubes are not vertical but are inclined to the horizontal and in which the gas carrying the particles ofgreater inertia are recycled aftyer the particles have been separated from the gas. t

In this modification the separator and classifier elements are contained in a container 39 having at least one vertically extending particle receiving chamber 40 in the inlet part of the container and opening downwardly into-a particle collecting hopper 41. Spaced to the rear of this compartment the container is recessed forwardly to an outlet tube sheet 42 spaced rearwardly fromthe chamber 40 to provide a plenum space 43 between the chamber 40 and the tuge sheet 42. In the plenum space 43 between the chamber 40 and the tube sheet 42 are positioned a number of centrifugal separator tubes 44 mounted in the rear wall of the chamber 40 and-off-take pipes 45 extending co-axially from the inlet, rear, part of the tubes 44 to deliver through the tube sheet 42 to exhaust to the atmosphere or to a stack, not shown. The tubes 44 and off-take pipes may be either horizontal or inclined upwardly toward the rear as shown in FIG. 7. Particlev laden gas passes from the inlet end of the container 39 as indicated by the arrow in FIG. 8 through passages 46 as shown in FIG. 8 between the chamber 40 and the side; walls of the container and between the chambers 40, if several chambers are provided in the container, to enter. sidewise into the plenum space 43 between the chamber 40 and the tube sheet 42. A number of vertically extending deflector vanes 47 are mounted in the container between the passages 46 and the plenum spaces and are inclined as shown in FIG. 8 as to cause a sharply turned flow of.

the gas passing from the passages 46 into the plenum space 43. In this sharply turned flow the particles of greater inertia pass over the deflector vanes to a second particle separator 48 while the particles of lesser inertia flow with the part of the gas passing between the deflector vanes to the centrifugal tubes 44.

That part of the gas passing over the deflector vanes 47 passes between horizontal, downwardly inclined, deflector vanes 48 and into a settling chamber 49. In this chamber, of which there is one for each passage 46, the particles settle downwardly by gravity aided by the downward momentum imparted to them as they are deflected downwardly by the vanes 48. Moreover, the velocity of the gas in this settling chamber is low and therefore has little lifting power. The gas is drawn from the settling chamber 49 through a by-pass duct 50 in a return circuit to passages between vanes 51 to the passages 46 to the plenum spaces and to the centrifugal tubes 44 with fresh incoming gas, there being thus a recycling of a part of the gas so that only cleaned gas passes out of the system. Any suitable. means may be used if necessary to cause the gas to flow from the settling chamber 49 through the duct 50 to the, passages 46.

In FIG. 9 another modification of a classifying and particle collecting system with a feed-back of gas from the settling chamber is shown. In this modification, a container 52 is provided with a horizontal tube sheet 53 dividing the container into a plenum chamber 54 above the tube sheet and a collecting chamber 55 below the tube sheet,

this collecting chamber havirig a particle receiving hopper 56 ."Mourr'te'd i'r'1 the tube"sheet"53 arecentrifugal tubes 57 fonseparating particles frorn'gas entering the tu bes and for delivringjthes'eparticles fo the c'ollectingchamber 55and the ho per 56." The separatedffromjtlrese particles passes through off-take pipes 58 intolwhich the cleaned" gas is deliveredfromfihe tubes 57 and "which deliyerfjthese gases from theappa ratus. 'Th'e"oif-take pipes m'a'ypass upwardlyflirou'gh the 'cov er ordeck of the container or may deliver intoinanifolds and thence to the atmosphere. I V

Gas to be cleaned is delivered to theplenum chamber 54 through an'inleii 59; passing-over an-upwardly inclined deflector 60 and thence .over upwardly and rearwardly inclinedvapes 61 positionedrbetween the, off-take pipes 58 asshownin thedrawing; The vanes 61 may be adjusted a to different angles of inclination .as in. the embodiments shown in FIGS. 18. Theparticles of higher inertia pass over these deflectors in the manner described above together with a part of the gas while the other part of the gas passes into the centrifugal tubes 57 carrying with it the particles of lesser inertia to be separated in the centrifugal tubes.

The portion of the gas that has passed over the deflectors 61 passes with the particles of greater inertia through an opening 62 into a settling chamber 63 in which the heavier particles settle into a collecting hopper, 64. Gas is recycled from the settling chamber 63 to the inlet 59 through a duct 64, being delivered to the inlet through downwardly inclined deflectors 65. A part of the gas to be recycled is drawn from the settling chamber 63 by a blower 66 delivering to the duct 64 with an aspirating action to induce a flow of the gas through the duct.

In the modification illustrated in FIGS. 10-12, a container 67 is divided by a vertical partition comprising a tube sheet 68 for centrifugal tubes 69, and a vertical tube sheet 70 for off-take pipes 71 into a plenum chamber 72, a particle collecting chamber 73 having a hopper 74 and an oif-take chamber 75. The tubes 69 and off-take pipes 71 are inclined to the horizontal as shown in FIG. 11 and inclined vanes 76 extending a downward inclination above the inlet ends of the tubes 69, the tubes 69 being arranged in horizontal rows and there being one deflector above each row. An angled deflector 77 extends from each of the deflectors 76 at the left or inlet end viewed as in FIG. 10. Gas to be cleaned enters the plenum chamber 72 in the direction of the arrow in FIG. 12. The incoming gas and suspended particles are deflected from the inlets to the tubes 69 by the deflectors or vanes 76 and, to enter the tubes, the gas must make a sharp change in direction so that the particles of greater inertia are deflected away from the tube inlets while the particles of lesser inertia flow with the gas entering the tubes and are separated in the tubes from the gas and ejected into the collecting chamber 73. A settling chamber 78 is provided at the delivery end of the plenum chamber into which the remaining gas carrying the particles of greater inertia is delivered. In this chamber the gas is relatively quiescent and the particles settle into a bin 79 while the gas passes to an exhaust, or re-enters the plenum chamber at favorable locations.

In the modification illustrated in FIGS. 13 and 14, a container 80 is divided by a horizontal tube sheet 81 into a collecting chamber 82 for separated particles and a hopper 83 for the particles and a plenum chamber 84 above the tube sheet. Centrifugal tubes 85 are mounted in the tube sheet and off-take pipes 86 to receive cleaned gas from the tubes and extend upwardly through the top or deck of the container. Gas to be treated enters the plenum chamber through an inlet 87. In the inlet and immediately in front of the plenum chamber are deflectors 88 one in front of each row of the tubes and off-take pipes, these deflectors having a rounded front and side edges. The top or deck is provided with an opening above each deflector and a damper 89 for each opening.

In back of each of the deflectors 88 is a vertical ridged element 90 extending forwardly from the foremost offtake tube to form a pair of inlets to the spacewi thin the deflector, Gas entering the inlet and passing to the plenum chamber my be jsharply deflected throug-h' these inlets tocarry a part of the gas freed-from the particles of greater inertia to the interior of the deflectorand to exhaust The remaining part: of the gas, now enriched with particles of greater inertia pass into and through the centrifugal separator tubes which are designed to separate only the particles of greater inertia while the gas carrying the'particles of lesser inertia pass into the off-take tube and to the exhaust. Y

In each of the various modifications embodying the invention a part of the "particle carrying gas is deflected sharply to withdraw particles of lesser inertia and leave the remaining part of the gas enriched in particles of greater inertia to be separately separated and thus classified from the particles of lesser inertia. i In the apparatus of our invention the classification of particles takes place in the gas by dividing-the gasinto' separate streams one'of'which passes in onedirection while the other turns from the first stream so that the inertia of particles having a higher inertia relative to their superficial area are carried with the direct stream while particles of less inertia relative to their superficial area are carried by the deflected streams because their superficial area acted on by the deflected gas stream overcomes their relatively lower inertia and momentum. It will be apparent that various modifications and arrangements of the particle separating means may be used within the scope of the invention and that the classified particles in suspension in the separate gas streams are capable of treatment in suspension.

What we claim is:

1. A particle classifier for differential classification and separation of particles from a gas having particles of different inertias relative to their superficial areas comprising:

(a) a generally horizontal container (15) divided by a generally horizontal partition (21) into a plenum chamber (30, 31) and a particle-collecting compartment (16, 17);

(b) a gas-receiving passageway (29) for carrying particle-laden gas therethrough and defining the path of travel of said gas and arranged to pass said gas downstream into said plenum chamber (30, 31);

(c) a plurality of centrifugal separating tubes (22) mounted in said partition (21) and arranged to receive the particle-laden gas from said plenum and pass particles separated from said gas portion into said particle-collecting compartment (16, 17);

(d) an open-ended off-take pipe (25) associated with each of said centrifugal separating tubes (22) and mounted in relation to said tube to exhaust to the atmosphere gas passing through said separator;

(e) a first hopper (19) disposed in said particle-collectin-g compartment so as to receive particles of relatively lesser inertia from a portion of said plurality of centrifugal tubes (22);

(f) a second hopper (20) disposed in said particle-cob lecting compartment for receiving from said plenum particles of relatively greater inertia from the remainder of said centrifugal tubes (22), said remainder of said centrifugal tubes and said second hopper and being disposed downstream of said plenum relative to said first hopper;

(g) a plurality of first deflectors (34) disposed over said first hopper (19) in said plenum and so-inclined as to allow a portion of said gas carrying particles of relatively lesser inertia to pass into said centrifugal separating tubes (22) and thereafter into said first hopper (19), and deflect a portion of said gas carrying particles of relatively greater inertia successively upwardly whereby said deflected gas is passed in agenerally. downstream direction toward said second hopper (20); and n 1 (h) a second deflector (32) positioned in said plenum upstream of said first deflectors (34) at an elevation above said first deflectors (34) and so-inclined as to deflect the particle-laden gas slightly upward .whereby a portion of said gas carrying particles of relatively greater inertia pass over said first deflectors (34 p 2. The classifier of claim 1 in which said centrifugal tubes are arranged in spaced rows extending lengthwise of the flow of gas through said plenum chamber and said first deflectors (34) are mounted transversely of said direction of [flow between said rows.

3. The classifier of claim 1 in which said centrifugal tubes are arranged in rows spaced transversely of said plenum chamber and in which in addition is provided a shield (36), extending vertically at a position upstream of said oflE-take pipes (25) one in advance of each row of centrifugal separators (22), said shields being so-formed to provide walled-passageways (38) to provide flow path v PH. j 1"} v for said gas in said plenum adjacent said separators (22). 4. A classifierv according t cclaim 1 inwhich saidfirst deflectors (34) are pivotally hinged. vto provide thereby means toadjust the angle of said deflectors. (34) relative to the flow pathtofv sai d gas. a J I} I I 5. A classifier according to claim 1 in which'said second deflector (32) is pivotally hinged to provide therew by means to ,adjustlthe angle of said deflector (32) relative .to the flowpath' of said gas. i

p References l it ed [UNITED 'sTATEsPATENTs c-- 2,632,527 3/ 1953" McBride 55-"348"X 2,773,598 12/ 1956 Caste'llani' 209 144 2,854,092" 92195 8 Gustavs son 55 349 f FQRE IQN PLATENTS 447,061 3/1948 Canada.

674,473 6/1952 Great-Britain;

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