US2363236A - Air-cooled muffler - Google Patents

Description

Nov. 21, 1944. P E FLUOR 2,363,236

AIR-cooLED MUFFLER Filed Aug. 13, 1943 i /9 4/ Z liz f 6k-4 A :1 Z'

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Patented Nov. 21, 1944 AIR-COOLED MUFFLER Peter E. Fluor, Santa Ana, Calif., assignor to The Fluor Corporation, Ltd., Los Angeles, Calif., a corporation of California Application August 13, 1943, Serial No. 498,601

13 Claims.

This invention has to do with mulllers for internal combustion engines, and in certain of its particular aspects, is concerned with improvements in air-cooled or induced draft muiller assemblies, in which the muiller proper is enclosed within an outer shell or conduit through which air-flow is induced by the discharge of gas from the muiller.

One major object of the invention is to provide a solution for a long standing and dimcult problem of properly muilling the exhaust gas impulses and sounds from Diesel or other two-cycle engines, as well as from four-cycle engines. It appears that because of the slower frequency of the exhaust gas discharges from the individual cylinders in four-cycle engines, the problem of mullling the sound has been less ditlicult, and various designs of muillers have been made to operate satisfactorily. Muffling of two-cycle engines, however, presents greater difficulties and, insofar as I am aware, entirely satisfactory muilling of such engines, at least of the heavier `duty sizes, has not satisfactorily been accomplished, especially by a muffler suitable for both four-cycle and vtwo-cycle engines. Extensive tests have shown that muiilers of the present design and construction perform at high eiliciency with either type of engine.

Another important feature and object of the invention, applicable particularly to vertical muillers, is the provision of a drain system for removing from within the mulller, particularly when the engine is not operating, water entering through the top, as during rains or under other circumstances, or where the muiller is used on a boat and water at times may wash into the muiller. In accordance with the invention, provision is made for arresting the flow of such water into the exhaust pipe and for draining the water from the muiller shell, as well as through the enclosing stack or air conduit where the muffler is used in an induced draft assembly.

The manner in which the aforementioned objects are accomplished, and various additional featuresand details best explained and understood by reference to a specific embodiment of the invention, will be described in the following. Reference is had to the accompanying drawing, in which:

Fig. 1 is a cross-section view showing a typical induced draft vertical muler assembly embodying the invention: and

Fig. 2is a cross-section on line 2-2 of Fig. 1.

The muiiler, generally indicated at I 0, is shown III to comprise an outer cylindric shell I I, a top cone I2 having an outlet I3, and a bottom cone I4 connected to the exhaust pipe I5 extending from the engine, conventionally indicated at I6. The shell II contains a plurality of concentric, annularly spaced bailles Il, I8, and I9, interconnected by spiders 20, the assembly of baffles being concentrically spaced and supported within the shell I I by spiders 2 I. The baffle assembly is closed at the top by a head 22 welded to the outer baffle I'I and against which the intermediate baffle I8 terminates. The top and bottom ends of baflles I9 and I8 are spaced respectively from the head 22 and plate 23, and baille Il extends the full distance between the head and plate, to cause gas flow along the inner bailles and nally outwardly through the perforations of the outer baffle as later more specifically considered.

The baille assembly is supported on an inclined oor or drain plate 23 having a central opening 24 through which gas discharged from the exhaust pipe I5 into the enlarged chamber 25, enters the innermost baffle I9. To obtain an initial dispersion and batlling of the gases flowing from chamber 25 into passage 26, a spider 2l, or other suitable baille means, may be placed at the inlet side of the opening 24. Access may be had to the chamber 25 for inspection or other purposes by Way of pipe 28 extending through the cone and stack, the outside of the inspection passage normally being closed by a removable cover 29.

In the type of induced draft installation shown, the muiller Il) is enclosed within an outer conduit or stack 30 including a cylindric shell section 3|, cone 32 and nipple 33 and a bottom cone 34 connecting with a continuing jacket or conduit 35 surrounding the exhaust pipe I5. The mufller IIl is suitably supported within the outer shell, as by spiders 36, to maintain the muiller outlet I3 in such predetermined relation to the stack throat 3l' that the exhaust gas discharge into the throat induces high velocity flow of air along the exhaust pipe and about the muiller through passages 38 and 39. Air may enter the conduit 35 at any suitable location, as at its open end near the engine. Suitable provision may be made for permitting expansion of the exhaust pipe below the fixed muiller, as by including in the exhaust pipe a section I5a made of suitable flexible material.

An important feature contemplated in the operation of the muilier proper, is the arrangement of the perforated bailles Il', I8, and I9 in a er causing the exhaust gases to iiow longi= tudlnally within and 'between the bellies, and at the same time to now transversely throughthe baille: apertures, to the end thatthe gases are required to aeV extended reversing straight path lines or now while subjected to the eects of transverse streams` passing through the bams apertures. The gases flowing upwardly through passage 26 reverse their path in owing downwardly through passage tl, and again reverse their ow upon entering passage 62 'from which the gases are discharged into space i3 through` the apertures in the outer baille il. Admixed with the gases flowing through passages lll and i2 are portions of the gas streams passing out through the apertures in baii'les it and i9. It is found that despite its emcient muing eiect on the gases, the baille assembly imposes very low back pressure on the engine.

' Although all the reasons for the efilcient operation of the muiller have not fully been determined, it is believed that the results are due largely to the capacity oi the baie assembly for permitting passage to the outlet lt within each interval of exhaust gas discharge from the engine, of substantially the entirety oi a quantity of escasas 'the outlet to' pass both vlongitudinally between `the bellies and through thebame perforations, vmeans for introducing vgas into one end of the innermost baille, and an imperforate closure for the opposite end ofthe baize assembly an end of each of said bailies being open so that the gas flows from said inlet longitudinally through the innermost name and then reversely and longitudinally through the space between said innermost baille and the next outer baille.

3. A muiiler comprising a shell having an inlet and an outlet, and a baille assembly within the Ashell including a plurality of spaced tubular permeans conning the discharge of gas from said gas corresponding to the volume of gas accompanying each discharge, and without any gaps" between the successive gas discharges through the muer as would otherwise tend to create intermittent pulsations or back ows. Not only is such continuity of the gas discharge important from the standpoint of sound muling, but also in producing a more constant uniform induction or air, at correspondingly increased rate, through passages 38 and 39 in response to the gas discharge from the muiner.

A further important feature is the provision of a controlled drain for removing from the muler, water entering it under such circumstances as previously mentioned.

Any water entering the mufter through the outlet i3 is deiected by the head 22 into space d3 so that the water collects upon and drains to the bottom of the inclined plate 23. The water then is drained from the muler through the outer shell Si, by way of pipe 35 carrying a valve d6 or other suitable closure. When the engine is not in operation, valve d@ may be left open so that any water entering the mulder will be immediately drained to the outside. During engine operation the valve of course will be closed. As will be observed, the position of plate 23 and its association with the drain pipe, electively prevent the water from reaching the gas inlet l5 and entering the exhaust pipe.

I claim:

1. A muliier comprising a shell having an inlet and an outlet, and a baiile assembly within the shell including a plurality of spaced tubular perforated baies one within the other and arranged to cause gases owing from said inlet to the outlet tc pass both longitudinally between the baiiles and through the baille perforations an end of each of said baiiles being open so that the gas ilows from said inlet longitudinally through the innermost baille and then reversely and longitudinally throughl the space between said innermost baille and the next outer baille.

2. A muliier comprising a shell having an inlet and an outlet, and a baflle assembly within the shell including a plurality of spaced tubular perforated ballles one within the other and arranged to cause gases flowing from said inlet to baille assembly to the perforations of the outer= most bale an end of each of said baffles being open so that the gas flows from said inlet longitudinally through the innermost baille and then reversely and longitudinally through the space between said innermost bams and the next outer baiile.

4. A muiler comprising a shell having an inlet and an outlet, and la battle assemblywithin the shell including a plurality of spaced tubular perforated bailies one within the other and arranged to cause gases owing from said inlet to the outlet to pass both longitudinally between the ballles and through the bafe perforations, means for introducing gas into one end of the innermost bame, and an imperforate closure for the opposite end o the baftle assembly, and an end of each of said bellies being on so that the gas ows from said inlet longitudinally through the innermost bafiie and then reversely and longitudinally through the space between said innermost baiiie and the next outer baille the discharge of gas `from said baille assembly being confined to the perforations of the outermost baille.

5. A muffler comprising a shell having an inlet and an outlet, a transverse wall within the shell between the inlet and outlet, a bale assembly at one side of said wall and including a plurality of spaced substantially concentric tubular perforated balles, said wall containing an opening through which gas flows from said inlet into the innermost baille, the gas thence flowing both longitudinally between the bames and through the baille perforations to said outlet, and an imperforate closure for the end of the baffle assembly furthest from said wall.

6. A mufller comprising a shell having an inlet and an outlet, a transverse wall within the shell between the inlet and outlet, a balle assembly at one side of said wall including an imperforate end closure spaced from said wall, an inner tubular perforated baille extending from a central opening in said wall toward said end closure, a second tubular perforated baille surrounding said inner baille and extending from said end closure toward said wall, and a third tubular perforated baille surrounding said second baffle and extend- `ing from said end closure to said wall, gas entering said inner baille owing longitudinally therethrough and thence twice reversing its ow in passing within spaces between the ballies to iinally gisfcharge through the perforations in said third 7. A muller comprising a shell having an inlet and an outlet, a transverse wall within the shell l one side of said wall including an imperforate end closure spaced from said wall, an inner tubular perforated baille extending from a central opening in said wall toward said end closure, bame means at the inlet side of said opening, a second tubular perforated baille surrounding said inner baille and extending from said end closure toward said wall, and a third tubular perforated baille surrounding said second baille and extending from said end closure to said wall, gas entering said inner baille flowing longipassage through the side of the shell directly tudinally therethrough and thence twice reversing its iiow ln passing within spaces between the baiiies to finally discharge through the perforations in said third baille.

8. A mumer comprising a vertically extending shell having an inlet from which exhaust gas passes upwardly within the shell to an outlet through which water may enter and now downwardly within the shell, baflie means inside the shell, an inclined transverse wall within the shell, and means for draining water from above the lower surface of said wall through the side of the shell.

9. A muilier comprising a vertically extending shell having an inlet from which exhaust gas passes upwardly within the shell to an outlet through which water may enter and iiow downwardly within the shell, a transverse wall within the shell having a gas-passing opening, baille means above said wall, and means forming directly above said wall a drain vpassage for withdrawing from the shell water deposited on said wall.

10. A muiiier comprising a vertically extending shell having an inlet from which exhaust gas passes upwardly within the shell to an outlet through which water may enter and flow downwardly within the shell, a transverse wall within the shell having a gas-passing opening, baille means above said wall and annularly spaced from said shell, an imperforate head closing the top of said baille means, means forming a water drain above said wall, and means for opening and closing said drain passage.

11. A muiller comprising a vertically extending shell having an inlet from which exhaust gas passes upwardly within the shell to an outlet through which water may enter and iiow downwardly within the shell, baille means inside the shell, an outer shell surrounding the muilier shell and forming therewith a passage through which air iiow is induced by the discharge of exhaust gases from the muffler outlet, means for diverting from said baille means the water entering the mumer, and means for draining the water through both of said shells.

12. A muiiier comprising a vertically extending shell having an inlet from which exhaust gas passes upwardly within the shell to an outlet through which water may enter and ow downwardly within the shell, a transverse wall within the muilier, baille means above said wall and spaced from said shell, an outer shell surrounding the muiiler shell and forming therewith a passage through which air iiow is induced by the discharge of exhaust gases from the muiiier outlet, and means forming a water drain outlet extending from directly above said wall through both of said shells. i

13. A munier comprising a vertically extending shell having an inlet from which exhaust gas passes upwardly within the shell to an outlet through which water may enter and flow downwardly within the shell, a transverse inclined wall within the muier, baille means above said wall and spaced from said shell, an outer shell surrounding the mumer shell and forming therewith a passage through which air iiow is induced by the discharge of exhaust gases from the mumer outlet, a drain pipe extending from above the lower side of said inclined wall through both of said shells, and an outside valve for said drain Pipe.

PEI'ER. E. FLUOR.

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