US2196491A

US2196491A - Apparatus for silencing and separating solid particles from pulsating gas streams

Info

Publication number: US2196491A
Application number: US248486A
Authority: US
Inventors: Alfred S Chipley
Original assignee: Burgess Battery Co
Current assignee: Burgess Battery Co
Priority date: 1938-12-30
Filing date: 1938-12-30
Publication date: 1940-04-09
Anticipated expiration: 1957-04-09

Description

APTII 9, 1940- A. s. CHIPLEY .1 6.491

APPARATUS FOR SILENCING AND SEPARATING SOLID PARTICLES FROM PULSATING GAS STREAMS Filed D80. 30, 1958 2 Sheets-Sheet 1 a7 2 z 4% Z i? V f 0 000 0000 00000 0000 00000 000 0000 00000 000 0000 9L 0000 0000 ooo 0000 0000 000 000 000 00000 27 000 63 0000 00000 000 000 0000 0000 000 53 000 00000 00000 jL 0000 000 0000 (30000 000 000 0000 O\oo00 00 11 00:50 obooo 000 Q -10 0000 0 /0000 00'0 oooq 0000 00015 9v 0000 0000 0000 O00 I 2 6.5 45- 6] 19 Xi A2 000 JZFE o O 9 m C/ 2 I April 1940. A s. CHIPLEY 2,196,491

APPARATUS FOR SL ILENCING AND SEPARATING SOLID PARTICLES FROM PULSATING GAS STREAMS Filed Dec. so, 1958 2 sheetsshet 2 c/jzz ejzz m j /gy Patented Apr. 9, 1940 UNITED STATES PATENT OFFICE Alfred s. Chipley, (mm, m, assignor, s'

mesne assignments, to

Chicago, 111., a corporation ofDeiaware Burgess Battery Com- Applieatlon December 30, 1938, Serial No. 248,186

.14 Claims.

This invention relates to means for silencing and attenuating the pulsations of a pulsating flowing gas stream and also means which, in addition, is capable of removing solid particles which may be'carrled by such stream. It relates to the provision of means of the character described which is especially adapted for application tothe intakes and exhausts of internal combustion engines, air compressors, and the like.

With silencers which have been proposed heretofore for application to engine exhausts, effective operation requires that they be placed at certain optimum locations with respect to the engine, this location being where the pressure variations in the gas stream are the greatest. At certain engine speeds. the exhaust pulsations become synchronized with the natural period of the exhaust system and miss the silencer is so placed at the optimum location, an amplification of the pulsations, and of the exhaust noises, occurs, these amplified noises being called period noises. In addition, effective silencers usually ofi'er substantial resistance to the flow of the as gases therethrough, with the result that considerable back pressure is created at the engine, air compressors, etc.

It is the object of the present invention to provide a silencing device which may be located so at any point with respect to the engine with equal effectiveness and which operates to eliminate period noises.

It is a further object of the invention to provide an attenuating device which offers a. mini- 5 mum of resistance to the flow of gases therethrough.

It is a further object of the invention to 'pro-' vide a device which removes solid particles from the gas stream in addition to attenuating the pulsations thereof, and one which is simple and economical of construction,

In the drawings, Figs. 1, 2, 3 and 4 are longitudinal sectional views of diiferent' modifications of the construction of this invention, and

Fig. 5 is a transverse sectional view along line 5-5 of Fig. 4. a

The device of Fig. 1 comprises a substantially imperforate casing I. having inlet and outlet 0 end walls II and I2, these end walls having inlet and outlet openings l2 and i4 therein respectively. The casing II is adapted to bearranged with its longitudinal axis disposed vertically and has two transverse partitions II and It therein 55 subdividing the easing into lowerandupper main chambers l1 and II and an intermediate chamber I! which is relatively short in comparison with chambers l1 and il.- An open-ended inlet tube 20- is mounted in inlet opening II and extends into chamber ii to a point adjacent and I spaced from partition II. A generally horizontal baiile member 2i surrounds the lower portion of inlet tube 20 within chamber l'lIand is spaced upwardly from the casing inlet wall ll. Baiiie member 2i is smallerthan the interior. cross- 10 sectional area of chamber i'l whereby communication is provided between the spaces below and above it. Inlet tube 20 may be perforated in that portion above bame member 2|. I

, Partition II has an opening 22 therein, which '1 is the outlet opening for chamber l1, and an open-ended tube 23, which is the outlet tube for chamber I1, is mounted at one end thereof in opening 22 and extends into chamber ii to a point adjacent and spaced from baiile member 2|. lube 2Iisoii'setwith respecttotube 2|,by

which is meant that tube 23 is not in alignment with tube 20 but is displaced laterally with respect thereto.

Tubes

20 and 28 overlap each other for a portion of their length in chamber .5 II, that is, they are co-extensive with each other for a portion of their length. The walls of tube 23 are perforated except for a portion, equal to about one-third of the circumference, which is disposed toward inlet tube 20, this portion being go imperforate.

Partition I. has two openings 2| and 25 therein, opening 24 being in substantial alignment .with tube 23 and opening 25 being offset with respect to said. tube and being substantially in 5 alignment with outlet opening ll of the casing l't. A perforated, open-mouthed, closed-ended tube 20 is mounted in opening 2i with its open mouth directed toward and spaced from the outlet end of tube 23, the spacing in this embodi- 0 meat being equal to the length of intermediate chamber is. The tube 28 is located within chamber IO, and a second tube 21, which is open at both ends and is perforated, is located within chamber II, and extends from opening 2! through outlet opening ll. The area of the wall of an imaginary cylinder coupling the outlet end 7 of tube 23 to the open mouth of the closed-ended tube 20 should be not less than the cross-sectional area of the outlet end of tube 23, that is, the path provided by' intermediate chamber II from tube 23 to tube 21 should be of a cross-sectional area at least as great as that of the outlet end of tube 23.

An opening a is provided in the 1mm inlet a wall or the casing. A removable cover 22 is provided for opening 28 and has a threaded shank 30 which passes through an opening in bracket 3|, a nut 32 being threaded upon the end of the shank 30 and cooperating with the bracket 3| in the usual manner to hold the cover 29 in the closed position. The opening 23 and cover 2! are of elongated shape, for example, elliptical, to make it possible to remove the cover for cleaning out solid particles from chamber II. An opening such as opening 28 with a removable cover for the cleaning out of solid particles in this manner is usually called a clean-out openin when the device is used for silencing and separating the sparks and other solid particles from the exhaust from an internal combustion engine, inlet tube 20 is connected to the exhaust pipe of the engine. In operation, the exhaust consists of a series of high pressure gas pulsations, usually called slugs, traveling at high velocity and separated from one another by areas of low pressure. The gases pass through inlet tube 20 and emerge from the open end thereof, a portion, particularly that at higher pressure, diffusing through the perforations of the tube wall as the gas travels along the tube. Within chamber I! the gases are free to expand into substantially the entire volumeof the chamber. and they are cooled and contracted, and their kinetic energy is reduced-to a large extent. As a result of such reduction of kinetic energy the solid particles which are carried by the gas descend by gravity to the lower portion of chamber l1 and settle upon bafile member 2|. The edge portions of the baiile member are inclined downwardly and the particles drift to the edge and drop into the space below the bafiie member. A large portion of the gases pass from the open end of inlet tube 20 to that of tube 23 and in so doing move downwardly within chamber l1 and reverse its direction in the lower portion of the chamber and move upwardly through tube 23. This reversal of d rection serves also to discharge solid particles which may be carried by the gas by inertia and such particles also settle on baiiie member 2|. Baiiie member 2| maintains the space beneath it as alone of quiescence which is substantially unaffected by the movement of gases within chamber i! so that the particles rest quietly until they are removed.

Considerable silencing takes place in chamber 11. In addition to that due to the expansion, cooling and contracting of the gases, further silencing is due to the diffus on of a portion of the gas pulsesat high pressure from inlet tube 20 into chamber l1 and from chamber l1 into outlet tube 23, through the perforations of said tubes, with a resulting levelling of! of such pulses.

The gases emerge from tube 23 in the form of modified slugs, and upon their entrance into intermediate chamber l9, may pass directly into tube 26, or may swerve laterally and enter tube 21 and pass through such tube to the atmosphere. They encounter a resistance at the mouth of tube 26, and the path through tube 21 offers the path of least resistance. A considerable portion of the gases follow it, but those pulses or slugs, which are at sufficiently high velocity are projected by their inertia directly across chamber l9, or the gap between

tubes

23 and 26, and into tube 26 where they continue toward the closed end of said tube. During this movement, the slug is dissipated gradually by progressive diffusion of the gas through the openings of tube 20 into chamber II with the result that the slug is substantially dissipated by the time it reaches the closed end of the tube. Its velocity energy is transformed into static pressure which is dissipated through the perforations of tube 21. In this way the tube acts effectively to reduce the slugs, or snub the high velocity pulsations, whereby there is a relatively smooth flow of the gases emerging from tube 26. The gases pass laterally from the perforations of tube 23 to the perforations of tube 21 and into the latter tube and thence to outlet opening I to the atmosphere. There may be some rise and fall in the pressure of the emerging gases but pulsations capable of producing objectionable noise are no longer present.

Because of its snubbing action upon the high velocity pulsations, as described, the tube 23 is called a snubber tube. It must be of sufficient volume and sufficiently perforated to accommodate the velocity peak portions of the slugs but must not be so extensively perforated that the slugs will be permitted to project through the walls of the snubber tube without undergoing the transformation described. In a particular commercial silencer employing a snubber tube arrangement similar to that shown in Fig. l, and designed for a single cylinder, 4 cycle, 2 horsepower gasoline engine having a 1 inch diameter exhaust pipe, the snubber tube is '1 inches long, and sufiiciently perforated with inch holes to render it 4% open, and the spacing or gap, between tube 23 and the snubber tube is 1 inch.

From the foregoing description of the action which takes place in the relatively closed snubber tube 26, it is better understood that the gases emerging from tube 23 encounter a resistance at the mouth of the snubber tube and the path of least resistance for them is laterally in chamber l3 and to the atmosphere by way of vent tube 21, and that a considerable proportion of the gases follow this path and only those high velocity pulses which possess sumcient inertia are projected across the gap and into the snubber tube. The resistance set up by the swerving of the gas stream from tube 23 to tube 21 is small, however, and the construction described has been found to create relatively small back pressure at the engine. Its action is equally effective regardless of its distance from the engine in the exhaust system.

The construction is very eifective for both silencing and solid particle removal. Because of the cooling and contraction which occurs in chamber H the upper portion of the device may be made smaller than otherwise could be done and there is economy and greater ease in meeting space limitations.

The upper chamber I3 functions eflectively as a secondary remover of solid particles. The diffusion of the gases from perforated tube 26 into the volume of chamber l3 causes a reduction of velocity and results in the settling by gravity upon partition I 6 of particles which may remain in the gases. A clean-out opening 33 may be provided in the wall of the chamber,

preferably near the partition I. for removing such particles. Said clean-out opening may be provided with a removable cover similar to cover 29 through which the particles may be removed. This is necessary only at infrequent intervals since the greater proportion of the particles are removed in the lower chamber H.

A threaded opening 3| may be provided in the side wall of chamber l1. If desired a pipe may be connected to this opening to supply a stream of water to the chamber to quench sparks and cool the casing l0, and also to flush out the collected solid particles. When such water supply is not used this opening is closed by a removable plug 35.

While the device described is intended to be arranged vertically, it may be adapted for horizontal arrangement by placing clean-out opening 28 in the side wall adjacent the inlet end of chamber l1, instead of in the end wall as shown.

The construction of Fig. 2 is along the same lines as that of Fig. 1 with the essential differences that the tubes within the first chamber are not in overlapping relation and the outlet tube of this chamber is of larger diameter than the inlet tube to produce a lower gas velocity therein. In addition, a receptacle is provided beneath the bottom wall of the device for collecting and retaining the solid particles.

The device comprises a substantially imperforate exterior casing 4|! having inlet and outlet end walls 4| and 42, said

walls having openings

43 and 44 therein. Two

transverse partitions

45 and 46 subdivide the casing 48 into a lower main chamber 41, an intermediate relatively small chamber 48, and an upper main chamber 43. The partition 45 has an opening 58 therein offset with respect to opening 43 in the inlet end wall 4 I, the opening 50 having an upwardly curved flange at its edge. An inlet tube 52 extends through inlet opening 43 and upwardly into the lower chamber 41 and an outlet tube 53, which is of larger diameter than inlet tube 52, and also of larger diameter than flanged opening 58, extends downwardly from said opening 58 a substantial distance into chamber 41. The inlet tube 52 is sufficiently short that it does not overlap outlet tube 53, and the interior end of tube 52 is cut at an angle and disposed so that the longest side is toward tube 53. Tubes 52 and 53 are imperferate. A substantially horizontal baiile member 54 surrounds the tube 52 near the upper end thereof and extends across the chamber 41. Baffle 54 actually forms the lower wall of chamber 41, but curved end wall 4| is provided to impart strength and symmetry. Bathe 54 is inclined slightly toward the portion of the chamber side Wall which is nearest inlet tube 52. A clean-out opening 56 is provided in said portion of the chamber side wall. A container 55 for the solid particles is fastened in suspended relation to said side wall and is arranged to receive solid particles whichpass through opening 56. For removing the solid particles, container 55 is separable at the line indicated at 64. The upper portion is fastened permanently to the chamber wall and has a collar 65 at its lower end. The lower portion is held removably in place by wing bolts 66 which pass through openings in said lower portion and are threaded into openings in the collar.

In upper chamber 49 a perforated, closedended, open-mouthed snubber tube 68 is mounted at its open mouth in an opening 6| in partition 46, which opening is in alignment with outlet tube 53 of the lower chamber. An open-ended, perforated outlet or vent tube 62 extends from a second opening 63 in partition 46 through casing outlet opening -44 to the atmosphere.

The operation of the device of Fig, 2 is similar to that of Fig; 1 except that a smaller proportion of the gases undergo two complete reversals of direction, and a substantial portion merely swerve from the end of inlet tube 52 to the end of outlet tube 53 in the lower chamber 41. A rotary motion takes place in this chamber which causes the gases to sweep across baffle 54 and move the solid particles through opening 56 and into the container 55. The enlarged diameter of outlet tube 53 results in lower velocity of the gases within suchtube, but the movement into and across chamber 48 and into snubber tube 88 is increased because of the construction which is found at flanged opening 58. The function of projecting the slugs or pulsations at high velocity across intermediate chamber 48 and into the snubber tube is, therefore, retained. This is the function which has been found to be highly effective in attenuating the velocity of such slugs.

A clean-out opening 61 is provided in the upper chamber in the same manner as described here tofore in connection with Fig. 1, for the purpose of removing solid particles which collect in said upper chamber.

Where it is not required to provide means for removing particles from the gas stream, the construction of Fig. 3 may be used. This represents a simplification which is highly effective for attenuating the noises and pulsations at high pressure which are present in intake and exhaust gases. It comprises a substantially imperforate casing having inlet and outlet end walls 1| and 12, these walls having inlet and

outlet openings

13 and 14 therein. Two transverse partitions and 16 are arranged within the casing to form an inlet chamber 11 which will be called an expansion chamber, and an outlet chamber 18, which will be called a snubber chamber, and a relatively small intermediate chamber 18.

An inlet snout 88 is mounted in inlet opening 13 and is adapted to conduct gases to the device, the inlet snout 88 stopping substantially at the inlet wall 1| and not extending into the expansion chamber 11. A perforated, open-ended outlet tube 8| for expansion chamber 11 is mounted at one end in an opening 82 in partition 15 and extends for a substantial distance into expansion chamber 11. Tube 8| is arranged in offset relation with respect to inlet snout 80. A perforated snubber tube 83 is mounted at its mouth in opening 84 in partition 16 and extends into snubber chamber 18, snubber tube 83 being in substantial alignment with outlet tube 8| of the expansion chamber 11. An open-ended, perforated vent tube 85 extends from an opening 86 in partition 16 through opening 14 in casing outlet wall 12 and to the atmosphere.

In operation the gases enter the device by way of inlet snout 88. Upon entering the chamber 11 they are free to expand throughout substan tially the entire volume of the chamber. If the gases are heated exhaust gases, they are cooled and contracted in chamber 11. From chamber 11 they pass into tube 8| through the open end thereof and the perforations in the wall thereof and emerge into intermediate chamber 18, where the pulsations which are at sufficiently high velocity are projected across said intermediate chamber and into snubber tube 83, the balance swerving in direction and passing through vent tube 85. It has been found that the device of Fig. 3 is highly effective for attenuating the energy of the slugs, and the period noises, the probable explanation being that the cooling and contraction which takes place in chamber 11 causes the energy of the pulsations entering snubber tube 83 to be reduced to a considerable extent, and the snubber tube and the chamber 18 complete the attenuation whereby a substantially smooth flow is obtained at the outlet of the device, the variations in the flow which may be present being of such gentle rising and falling nature as to be incapable of creating objectionable sounds.

A further modification of the invention is shown in Figs. 4 and 5. In this modification the substantially imperforate outer casing is subdivided into an expansion chamber 9|, an intermediate chamber 92 and a snubber chamber 93 by

partitions

94 and 95, partition 94 having opening 96 therein and partition 95 having openings 9'! and 98 therein, these openings being of substantially the same arrangement as the corresponding openings in the construction of Fig. 3.

The inlet end wall of the casing has an opening 99 therein and an inlet snout I00 passes through said opening and projects a short distance into the expansion chamber 9|. A second tube IOI, which is the outlet tube for expansion chamber 9|, is mounted at one end in opening 96 of partition 94 and extends into chamber 9I. Tube IOI has imperforate walls, but has a longitudinal slot'I02, see Fig. 5, in the side thereof disposed toward inlet snout I 00.

Two baiile plates I03 and I04 also extend inwardly into chamber 9I from partition 94 in spaced, substantially parallel relation to outlet tube IOI. These baiiies are arranged at an angle to each other and are arranged with respect to outlet tube IOI in such manner that in crosssection they forma V with the outlet tube IOI partially within the V. The baflies are spaced apart so that there is a gap or slot I05 at the junction of the legs of the V.

The construction of the snubber chamber 93 is similar to that of snubber chamber I8 of Fig. 3.

It has perforated snubber tube I00 extending into it from opening 91 in partition 95, and perforated vent tube I0'I extending from opening 98 in partition 95 through outlet opening I09 of the casing 90.

The operation of this modification is similar to that of the form of Fig. 3, the baffles I03 and, I04 preventing the too ready flow of gases from inlet snout I 00 to outlet tube I M The gases flow around baffles I03 and I04 and through slot I05 with very slight restriction, such restriction being only sufiicient to cause the gases to employ substantially the entire volume of chamber 9I whereby they undergo expansion and contraction, and to prevent them from taking the short path directly across the intervening space between snout I00 and tube IN. The slot I05 between bailies I03 and I04 may be omitted if desired, and these bailles may be joined together at the apex of the V.

The gases pass out of chamber 9| by way of tube IOI and are directed thereby toward snubber tube I05. The action within intermediate chamber 92 and snubberchamber 93 is the same as that described in connection with the construction of Fig. 3.

The slotted tube IOI of Fig. 4 performs in a manner similar to the perforated tube 8| of Fig. 3, and the corresponding tubes of the other modifications, and a bafile capable of performing in a manner similar to the baflles I03 and I04 of Figs. 4 and 5 may be used in the other modifications if desired.

Further modifications may be employed if desired. For example, the inlet and outlet tubes of the first chamber need not be mounted upon opposite walls, but may be mounted on adjacent walls, and also on the same wall. For manufacturing convenience they are usually mounted on opposite walls. Also, the structure of Fig. 3 may be compounded and two outlet tubes provided for the expansion chamber, arranged oflset with respect to the inlet tube, and two snubber tubes in the snubber chamber and a single vent tube, preferably centrally of the chamber, may be used. Also, the device may be adapted for application to an engine having two (called twin) exhaust lines, such as is frequently employed in the larger automotive and other engines. In such case two inlet tubes may be provided for the expansion chamber and a single outlet tube may lead to a snubber section substantially similar to those described herein. Such modifications may also be incorporated in the constructions of Figs. 1 and 2 where means are provided for separating solid particles from the gas stream. In these constructions it is advisable that the chamber in which the solid particle separation takes place precede the snubber chamber, but in the constructions which are not concerned with the separation of solid particles, the-expansion chamber may follow the snubber chamber. In such construction the snubber tube is placed substantially in alignment with the inlet snout of the device, and the outlet tube of the expansion chamber is arranged in offset relation to the outlet tube of the snubber chamber. Other modifications may be made without departing from the spirit of the invention.

The constructions which have been described herein possess the advantage explained heretofore, that they are equally effective for attenuating noises and pulsations regardless of their location in the exhaust system.

I claim:

1. Apparatus for attenuating noise-producing flowing gases comprising a chamber, a wall of said chamber having an inlet opening therein, an open-ended perforated outlet conduit extending into said chamber from a wall thereof, said inlet opening and said-outlet conduit being arranged in non-aligned relation to each other, said inlet opening and the open end of said conduit within said chamber being in free communication with substantially the entire volume of said chamber, a second chamber, a wall of said second chamber having an inlet opening therein, a perforated open-mouthed, closed-ended snubber tube in substantial alignment with said second chamber inlet opening with the said mouth thereof directed toward and spaced from said second chamber inlet opening, a vent tube extending into said second chamber from a wall thereof, said vent tube being arranged to cause a relatively abrupt deviation of the gases passing from said second chamber inlet opening to said vent tube, the outlet of one of said chambers being connected to the inlet of the other.

2. A device for attenuating noise-producing flowing gases comprising a chamber, an openended inlet conduit extending into said chamber from a wall thereof, an open-ended outlet conduit extending into said chamber, said conduits being arranged in non-aligned relation to each other and the open ends of said conduits within said chamber being in free communication with substantially the entire volume of said chamber, a. second chamber, a perforated, open-mouthed, closed-ended snubber tube arranged within said second chamber in substantial alignment with said outlet conduit with the mouth thereof directed toward and spaced from the outlet end of said outlet conduit, and means forming a vent passage from said second chamber to the atmosphere, said vent passage communicating with said outlet end of said outlet conduit.

3. A device for attenuating noise-producing flowing gases and separating solid particles therefrom comprising a chamber, an open-ended inlet conduit extending into said chamber from a wall thereof, a second open-ended conduit extending into said chamber, said conduits being arranged in non-aligned relation to each other and the open ends of said conduits within said chamber being in substantially free communication with substantially the entire volume of said chamber, a second chamber, a perforated, openmouthed, closed-ended snubber tube arranged in said second chamber in substantial alignment with said second conduit with the said mouth thereof directed toward and spaced from the open end of said second conduit, a vent tube extending into said second chamber from a wall thereof affording direct communication between the outlet end of said second conduit and the atmosphere, the end of said vent tube being arranged in such manner as to cause a relatively abrupt lateral deviation in the path of gases passing from said second conduit to said vent tube, said first chamber having a clean-out opening in a wall thereof to permit removal of said particles therefrom.

4. A device for attenuating noise-producing flowing gases and separating solid particles therefrom comprising a chamber, an open-ended inlet conduit extending into said chamber from a wall thereof, a second open-ended conduit extending into said chamber, said conduits being arranged in non-aligned relation to each other and the open ends of said conduits within said chamber being in free communication with substantially the entire volume of said chamber, a second chamber, a perforated, open-mouthed, closed-' ended snubber tube arranged in said second chamber in substantial alignment with said second conduit with the said mouth thereof directed toward and spaced from the open end of said second conduit, a vent tubeextending into said second chamber from a wall thereof and affording direct communication from said second conduit to the atmosphere, said vent tube being arranged so as to cause relatively abrupt deviation in the path of gases passing from said second conduit to said vent tube, and a baffle in said first chamber and below the open end of said inlet conduit, said baille being constructed and arranged to provide a zone of quiescence beneath said baiile and in communication with the space above said baille.

' 5. An apparatus for silencing noise-producing flowing gases and separating said solid particles therefrom comprising a lower chamber and an upper chamber, means in said lower chamber for separating solid particles from a flowing gas stream, an open-ended conduit for directing gases leaving said lower chamber, a perforated open-mouthed, closed-ended snubber tube in said upper chamber and in substantial alignment with the gas exit end portion of said conduit with the open mouth of said snubber tube arranged toward and spaced from said end of said conduit, and a perforated vent pipe extending into said upper chamber from a wall thereof, said vent pipe communicating with the open-end of said conduit and leading through said upper chamber to the atmosphere, said vent pipe being arranged in offset relation to said conduit, the perforations of said snubber tube being in communication with the perforations of said vent pipe within said upper chamber.

6. An apparatus for silencing noise-producing flowing gases comprising an expansion chamber, means for conveying said gases to said expansion chamber and permitting said gases to expand freely into substantially the entire volume of said chamber, an open-ended gas-directing conduit for convey g gases from said expansion chamber, a second chamber, a perforated openmouthed, closed-ended snubber tube arranged in said second chamber in substantial alignment with said conduit with the open mouth of said tube arranged toward said conduit, said tube and conduit being spaced apart to provide a gap between the open ends thereof, and a vent pipe extending into said second chamber from a wall thereof and affording direct communication between said gap and the atmosphere, said vent pipe being arranged in offset relation with respect to said conduit and snubber tube.

7. An apparatus for silencing noise-producing flowing gases and separating solid particles therefrom comprising a substantially imperforate shell, a partition in said shell dividing said shell into a plurality of chambers, means in one of said chambers for separating solid particles from said gas stream, an open-ended gas-directing conduit leading from said chamber and opening into the second of said chambers, a perforated open-mouthed, closed-ended snubber tube in said second chamber and arranged in substantial alignment with said conduit and with its open mouth toward and spaced from the open end of said conduit, and a vent pipe extending into said second chamber from a wall thereof and affording direct communication between the space between said conduit and said snubber tube and the atmosphere, said vent pipe extending in substantially the same direction as said conduit and being in onset relation to said conduit.

8. An apparatus for silencing noise-producing gases and separating solid particles therefrom comprising a casing, said casing being subdivided into a plurality of chambers, an open-ended conduit leading into the first of said chambers, a. second open-ended conduit of greater cross-sectional area than. said first conduit extending downwardly into said chamber from the upper wall thereof, said conduits being arranged in offset relation with, respect to each other, the open ends of said conduits within said first chamber being in free communication with substantially the entire volume of said first chamber, a perforated, open-mouthed, closed-ended snubber tube in the second of said chambers, said snubber tube being arranged in substantial alignment with said second conduit and with its open mouth. disposed toward and in spaced relation to the upper end of said second conduit, and an openended vent pipe extending into said second chamber from a wall thereof and affording direct communication between said space between said snubber tube and said second conduit and the atmosphere, said vent pipe being arranged to cause a relatively abrupt lateral deviation of the gases passing from said second conduit to said vent pipe.

9. A device for silencing noise-producing flowing gases comprising a casing, two spaced-apart partitions within said casing subdividing said casing into two main chambers and an intermediate chamber, open-ended inlet and outlet conduits projecting into the first of said main chambers from opposite walls thereof said conduits being arranged in offset relation with each other within said chamber, the open ends of said inlet and outlet conduits within said first chamber being in substantially unconfined communication with substantially the entire volume of said first chamber, the partition between said second main chamber and said intermediate chamber: having an opening in substantial alignment with said outletconduit, a perforated, openmouthed, closed-ended snubber tube mounted in said opening with its open mouth opening into said intermediate chamber and directed toward and spaced from said open end of said outlet conduit, a perforated vent conduit communicating with said intermediate chamber at a point in offset relation to said outlet conduit, said vent conduit passing through said second main chamber, the perforations of said snubber tube being incommunication with the perforations of said vent conduit within said second main chamber.

10. An apparatus for silencing noise-producing flowing gases and separating solid particles therefrom comprising a chamber having inlet and outlet openings in opposite walls thereof, openended inlet and outlet gas-conducting conduits extending into said chamber from said opposite wall openings respectively, said conduits being co-extensive for a portion of their length whereby gases passing from the open end of one to the open end of the other reverse their direction of flow from the direction of flow in said conduits, the openends of said conduits within said chamber being in substantially unconfined communication with each other within said chamber, a second chamber having a wall thereof adjacent to and spaced from a wall of said first chamber, said second chamber wall having an opening therein in substantial alignment with the outlet conduit of said first chamber, a perforated openmouthed, closed-ended snubber tube mounted in said second chamber wall opening and extending into said second chamber with the open mouth thereof directed toward and spaced from said outlet conduit, said second chamber wall having a second opening therein and an open-ended perforated vent tube mounted in said second open; ing and extending through said second chamber to the atmosphere, a battle member in said first chamber below the open ends of the conduits within said first chamber, said baille member being constructed and arranged to provide communication between the spaces above and below it.

11. A device for silencing noise-producing flowing gases and separating solid particles therefrom comprising a casing, two spaced-apart par-" titions within said casing subdividing said casing into a lower chamber, an upper chamber and an intermediate chamber, open-ended inlet and outlet conduits projecting vertically into said lower chamber from opposite walls thereof said conduits being arranged in offset relation with each other within said chamber, the open ends of said inlet and outlet conduits within said lower chamber being'in substantially unconfined communication with substantially the entire volume of said lower chamber, and a baiile member arranged across said chamber below the open ends of said conduits, a wall of said lower chamber having a clean-out opening therein above and in adjacent relation to said baille, said opening being in a portion of said wall which is remote from said outlet conduit, the lower wall of said upper chamber having an opening in substantial alignment with said outlet conduit, a perforated, open-mouthed, closed-ended snubber tube mounted in said'opening with its open mouth opening into said intermediate chamber and directed toward and spaced from said open end of said outlet conduit, a perforated vent conduit communicating with said intermediate chamber at a point in offset relation to said outlet conduit, said vent conduit passing through said upper chamber, the perforations of said snubber tube being in communication with the perforations of said vent conduit within said upper chamber.

12. The device of claim 11 in which a cleanout opening is provided in the wall of said lower chamber beneath said bai'ile member.

13. In a device of the character described, a

casing, an open-ended inlet tube passing through a wall of said casing, a partition within said casing in spaced substantially parallel relation to said inlet wall, said partition subdividing said casing into an inlet chamber and a second chamber, said inlet tube opening into said inlet chamber, said partition having an opening therein substantially in alignment with said inlet tube, a perforated, open-mouthed, closed-ended snubber tube mounted in said opening with the open mouth thereof arranged toward and in spaced relation to the exit end of said inlet tube, and a perforated vent pipe communicating with said inlet chamber and leading through 'said second chamber to the atmosphere, a wall of said second chamber having a clean-out opening therein.

14. The construction of claim 13 in which the vent pipe extends generally parallel and in offset relation to the snubber tube.

- ALFRED S. CHIPLEY.

CERTIFICATE OF CORRECTION. PatentNo. 2,196,191. April 9, 19L;o.

' ALFRED s. CHIPLEY. A

It is hereby certified that errofi appears in the printed sgec'ification of the above numbered patent requiring correcti'onas foliows: Page 5, second column, line? for the wo-rd "construction" read -'constri ction--; and

that the said Lettere Patent should be read with this correction therein that the heme may conform to the record of the case in the Patent Office.

Signed and sealed. this l8thday of June, A. D. 1914.0.

Henry/Van Arsdale, (Seal) Acting Commissioner of Patents.

v CERTIFICATE OF CORRECTION. Patent No. 3496,1491. A ril 9, 191m,

' ALFRED s. cHIrLEY. I

It is hereby certified that errofi appears in the printed specification of the above numbered patent requiring cori-ectionas foliows: Page 5, see- I end 001mm,. l1ne 7,, for the wb-rd "construction" read "constriction"; and that the said Letters Petent should be read with this correction therein that the 'aame may conform to the reeord of the case in the Patent office.

Signed and sealed this 18th day or June, A. D. 191m;

. 1 HenrjQVan' Arsdale,

('Seal) Acting Commissioner of Patents;