US871775A - Muffler. - Google Patents

Description

No 871,775. PATENTED NOV. 26, 1997.

F. O. BLANGHARD & E. B.'GROGKE R. I

MUFFLER.

APPLIUATION FILED JULY 22. 1907.

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No. 871,775. 7 I PATENTED NOV. 26, 1907.

F. 0. BLANGHARD & B. B. OROGKER. 7

MUFFLER.

APPLIUATION FILED JULY 22. 1907.

2 SHBETS-SHBET 2. 3

CONNECTICUT.

Fro v FREDERICK C. BLANCHARD AND ERNEST B. OROGKER, OF .BRIDGEPORT, CONNECTICUT,

ASSIGNORS TO THE CONSOLIDATED SAFETY VALVE, COMPANY, A CORPORATION OF MUFFLER."

i tnam filed July 22.1907. Serial No. 384.898.

'Connecticut, havo'invented new and useful Improvements in Mufflers, of which the followig is a specification.

Mg invention relates to the construction of mufflers such as are employed to deaden the noise of exhausting steam or other gases, andconsists in improvements in the muffling devices, whereby the efficiency of mufflers is improved and their effective operation facilitated. I In particular, I have contrived my improved mufi'ler for steam-escape and safety valves, though my improvements are adapted to other situations and may be used for muflling purposes Wherever it is desired to suppress the'noise of escaping gases.

I am aware that safety valve and other mufilers have been designed and manufactured, wherein several contrivances for breaking up, baffling, and distributing the steam of escaping gas have been suggested or employed. Baflie plates, inclosed in a shell or drum through which the gases pass to the atmosphere, are an old device, and transverse bafileplates have been employed in which a multitude of perforations performed the muflling function. I am informed also, that mufflers using rolls or cylinders of woven wire fabric, others using a mass of metal chips or lathe turnings, others using a mass of small fragments of stone,

glass or other solid material, and still others using coiled springs, spirally coiledin the mufiler drum, have been suggested or used, and I am personally familiar with some of the practices mentioned. While any or all of these muflling devices serve in some measure to perform the essential function of breaking up and baffling the stream of escaping steam or other gas, they do not, so far as I am'aware, serve the purpose as well as is desirable. The irregularities of coiled wire springs, or woven wire fabric, are not sufficiently pronounced to obtain the best effect, and mufflers composed of masses of fragments are liable to become matted and practically impervious in some port-ions, leaving other portions much too free and unob- Specification of Letters Patent.

.tion of the instrument as a whole. observed, in experiments with broken-fragment mufflers, that the fragments where- Patented 1\'l'ov.? 26, 1907.

structed to perform the muffling function properly, as they leave the steam or other gases free to follow a course of least resistance, which is 'recisely what a muffler should not do. n the other hand should a muffler be too closely restricted in its subdivided passages, it will restrict theescape of gases unduly, and possibly interfere, by creating back pressure, with the proper Iopleraave with the muffler she'll is'filled become chipped and comminuted by the agitation produced by a blast of gas, and deliver uantities of dust and grit, produced by the reaking up of the fragments in the muffler shell. Thus, little by little the muffler so constructed becomes deteriorated and more and more in-. efficient. I

'I have determined by experiment and trials, that essentially the best instrument for retarding and breaking up a stream of gas, is a flat plate, since the effect of a plate on the impinging stream is to explode" it, so to speak, by spattering it in all directions.

I have further determined that if a large number of small separated baflle plates are opposed to the passage of the stream of steam or other escaping gas, so that the gas must inevitablyimpin'ge repeatedly against the surfaces of these plates and be obliged to find its way over the edges thereof the effect is still further improved. I believe that this improvement in the muffiing effect in case a multitude of small thin baffle plates is employed is due to the fact that not only is the stream of gas scattered by im inging u on safety valve muffler; Fig. 2, is a detail in ele-- vation, showing the form of muffiing device which I-employby preference; Fig. 3, isa side view of thedetailshown in Fig, 2; Figs- 4, 5 and 8 are elevations showing the details;

In Fig. 1, A represents a safety valve casing in which the valve B is seated, the valve 1 being held to its seat in the usual manner by the spring E. The upper part D is mounted in the usual Way on t e upper portion of the valve casing from which the segmental pas sages 0 lead and areinlets to the muflier space. The 'mufller s ace is inclosed between the outer shell and the inner cylind ncal portion of the top castingjD this shell 1 being. provided with an upper inturned flange G, which is filled with erforations g; the shell is seated at the top of the casting D, and at the bottom of the outer edge of the flange or mm d whereto the shell is secured into-place, as at n.

My 1111 roved muflling contrivance is shown at m Fig. 1, and is contained within the muffler space between the top casting D and shell F.

While I have shown in Figs. 1. 2 and 3 the form of muflling device which I have selected; by preference, the principle of constructlon is perhaps better illustrated by Flgs. 4 to 9 inclusive, which show alternate modes of constructing my improved mufiling device. In Fig. 4, for instance, there is shown a fragment of a thin metal sheet in whlch seml-circular holes t" are cut, leaving the material uncut along the diameter of each of the holes so that fins or shelves 'i are formed standing out" at.an angle from the sheet I. TlllS angle may be a right angle or any other angle desired; I prefer to turn the sald shelves out at substantiallyright angles for the reason that I believe the ifiuflling effe, ct 1s best attained in this manner. In Figs. 4 and 5 the shelves '5 are shown as lying 1n planes parallel to the upper edge of the sheet I, but if desired the shelves i may be formed so that they stand not onl at an angle to the general surface of the siieet but are also slightly inclined in relation to the upper edge, as shown in Fig. 6 or as shown in Fig. 8', the shelves 1) may some of them be inclmed 1n one direction and others in the opp os1t'e direction. tioned construction and, as shown in Fig. 9,

prefer to stagger the holes i; and to make the inclination of the shelves & alternate from row.to row horlzontally. In no case, however, do I consider it advisable to incline the shelves much more than 30 degrees from the upper edge of the sheet.

I take a sheet I of such height as to extend from top to bottom of the space within the muffler shell and of such length that when the plate is rolled 'into a helix so that the shelves of'feach' turn touch the back of the plate at the next turn or convolution, the entire helix will substantially fill the muffler space.' In punching the holes '1'. and forming I prefer the last men' the shelves i it is desirable to make as many perforations and shelves as the material of the sheet I will accommodate, because the larger the number of shelves the more efl'ctively will the muflling function be performed and the larger the number of perforation-2 the more freely will the stream of gas pass through the entire mufiler.

In Figs. 2 and 3 I have shown in plan and j edge view, res actively, a fragment of socalled expandec metal, which by virtue of its.

peculiar, construction brings the aggregate Y aperture surface to a maximum, and ikewise presents the largest possible number of laterally projecting fins or shelves. By preference, therefore, and for convenience in manufacture I select for my muflling device a helically rolled sheet of expanded metal and have shown such a sheet at I in Fig. 1. The expanded metal provides by its mesh the requisite large number of baffling shelves which stand out at an an le closely approaching a right angle from the sheet as a whole and which affords also the largest possible measure of apertures through the sheet.

Steam or other escaping ases passin from the inlet of the muffler shel as at C in .ig. 1, to the outlet, thereof as provided by the perforations g; which scatter the gas streafn in every direction and which by reason of their thin sharp edges and fiat up er surfaces also break the gas up into a mu titude of eddies and by this mode of operation effectively deaden the noise which otherwise would be made by the escaping gas. 7 The stream of steam or other gas is as a whole subjected to so little interruption by this mufiling device that no appreciable back pressure is created th ere-by.

Mechanically considered the muffling device shown and described has also this advantage that while abundantly perforated it is nevertheless a rigid and continuous sheet which resists any tendency to alteration in the size 01" distribution of the apertures.

'What I claim and desire to secure by Letters Patent is:

In a mufllena shell provided with an inlet and an outlet and a muflling clement, inclosed in and substantially filling the shell, consisting of layers of apertured sheet metal laid. parallel to the course of gases passing from the inlet to the outlet and. formed with shelves standing out at an'angle from the layers of sheet metal.

2. In a muffler, a shell provided with an inlet and an outlet and a mufl'ling element, inclosed in and substantially filling the shell, consisting of layers of apertured sheet metal laid parallel to the course of gases passing from the inlet'to the outlet and formed with shelves standing out at an angle from the sheet metal layers, the shelves also inclined to the axis of the shell.

3'. 111's muffler, a shell provided with an inlet and an outlet and a mutiling element, inclosed in and substantially filling the shell, and consisting of a helically coiled apertured metal sheet formed with shelves standing out at an angle from the sheet, the axis of the coil'substantially parallel to the course of the gases passing from the inlet to the outlet.

4. In a muffler, a shell provided with an inlet and an outlet and a In'uflling element, inclosed in and substantially filling the shell,

- and consisting of a helically coiled apertured metal sheet formed with shelves standing out at an angle from the sheet, the axis of the coil substantially parallel to the course of gases passing from the inlet to the outlet, the saiil shelves also inclined to the axis of the col 5. In a muhhrr, a shell provided with an inlet and an outlet and a muflling element, inclosed in and substantially 'Iilling the shell, consisting of layers of apertured sheet metal laid parallel and formed with shelves standing out an angle from the sheet metal layers.

6. In a muffler, a shell provided with an inlet and an outlet and a muifling element,

inclosed in and substantially fillin the shell,

consisting of layers of a ertured s eet metal 4 laid parallel and forme with shelves standing out at angle from the sheet metal layers, the said shelves also inclined to the axis of the shell. I

7. In a mufller, a shell provided with an inlet and anoutlet and a muflling element inclosed in and substantially filling the shell, consisting of parallel layers of expanded metal.

8. In a mufiier, a shell provided with an inlet and an outlet, 'a'mufliingelement inclosed in and substantially filling the shell consisting of a helical coil of expanded metal,

the axis of" the coil parallel to the course of gases from the inlet to the outlet of the shell. Signed by us at Bridgeport, Fairheld county, Connecticut, this 12th day of July FREDERICK (l. BLANCIIARI). ERNEST B. CROCKER.

VVtnesses:

W. R. CLARKE, WM. R. S'ruonn.

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