US2321362A - Thermic siphon - Google Patents

Description

June 8, 1943- G. J. cHRlsTENsoN THERMIC SYPHON Filed May 20, 1940 2 Sheets-Sheet 1 f Illllnlllllll Y .f l

Mwfw/ ewa@ THERMIC SYPHON Filed May 20, 1940 2 Sheets-Sheet 2 ms; /C -Cqm Patented June 8, 1943 THERMIC SEPI-ION Gust J. Christensen, Chicago, Ill., assigner to Locomotive Firebox Company, Chicago, Ill., a

corporation of Delaware Application May 20, 1940, Serial No. 336,162

2 Claims.

This invention relates to -improvements in thermic siphons and it consists of the matters hereinafter described and more particularly pointed out in the appended claims. The present invention is more especially concerned with siphons of the so-called duplex type, wherein the body thereof has more than one water inlet, as distinguished from siphons of the so-called Nicholson type, wherein the body has only one water inlet.

- A siphon of either type may well be used in a locomotive boiler iirebox requiring only one siphon. However, thermic siphons are frequently used in fireboxes requiring three siphons, and these are arranged as two side siphons and a center siphon. Heretofore, in three siphon installations, it has been the practice to use a center siphon of the Nicholson type and two duplex type siphons, one spaced laterally from each side of the center siphon. The reason why both types of siphons were heretofore employed in a three siphon installation, is that with duplex siphons as heretofore constructed, the two inlet necks thereof could not well be accommodated in the center of the rebox where the front throat sheet of the rebox has the least height.

One of the objects of the present invention is to provide a siphon of the so-called duplex type which is practical to install and use either as a single siphon arranged centrally in a relatively narrow firebox or to install or use in triplicate in a relatively wide rebox and arranged as a center siphon and two side siphons respectively.

Another object of the invention is to provide a duplex type of siphon, which when used in multiple in a relatively wide rebox, has parts so disposed therein as ably to support the brick of a fire arch without the aid of arch tubes heretofore necessary in a multiple siphon installation.

A further object of the present invention is to provide a siphon of this kind which has greater exibility than has heretofore been possible, so that it more ably accommodates itself to movement of the rebox sheets due to temperature changes, and this without damage to itself or to said firebox sheets.

Still a further object of the invention is to provide a siphon of this kind that requires the making of a fewer holes in the sheets of the iirebox and may be installed at low cost.

Again, it is an object of the invention to provide a siphon of this kind in which it is possible to provide a greater volume of Water for that part of the siphon body subjected to the highest temperature when installed inthe rebox of a locomotive boiler. l Y

Furthermore, it is an obect of the invention to provide a siphon of this kind in which it is prac- Y tical to employ a smaller diameter tube as an inlet for a part of the body, which tube may be more easily bent to the desired shape and which will have more flexibility to absorb the stresses imparted thereto, thus avoiding cracking or splitting.

The above mentioned objects of the invention, as Well as others, together with the several advantages thereof will more fully appear as the speciiication proceeds.

In the drawings:

Fig. 1 is a longitudinalvvertical sectional view through the frebox end of a locomotive boiler and in which the improved thermic siphon has been installed in triplicate.

Fig. 2 is a ,transverse vertical sectional View through the firebox appearing in Fig. 1 as taken on the line 22 of said Fig. 1.

Fig. 3 is an end elevation of the improved thermic siphon as viewed from the front thereof 'taken on the line 8 8 of Fig. 1 and illustrates one way whereby plain rectangular rebrick may be cut away at certain corners to pass about the connection the auxiliary water inlet has with the main inlet of the improved siphon.

Fig. 9 is a View similar to Fig. 8 and illustrates a modified form of brick which may be employed to pass about the connection said auxiliary water inlet has with the main inlet of the improved siphon.

Referring now in detail to that embodiment of the invention, illustrated in Figs. l, 2 and 3 of the accompanying drawings. 5 5 indicate the side sheets of the rebox of a locomotive boiler and 6 indicates the crown sheet. 1 indicates the front or nue sheet thereof and 8 indicates the .back sheet thereof, the lower portion of the flue sheet being formed to provide the inside throat sheet 9. It will be understood that the rebox is positioned in the rear end of the boiler shell which includes the outer side sheets III-IIJ, the usual top sheet Ia appearing in Fig. 2, back sheet II and outside front throat sheet I2. Portions of the back sheets 8 and II respectively, are formed to provide a fuel door I3.

The several sheets mentioned coact to form the side water legs I4, back water leg I5 and front throat I6, all bottomed by a mud ring I1. The above is typical of a conventional locomotive boiler rebox and adjacent parts and requires no further description except to say that companion sheets are suitably staybolted.

The firebox, which as herein shown is a relatively wide one, is equipped with a. plurality of improved thermic siphons I8 of the duplex type, in this instance three in number. In Fig. 2, these siphons are shown as arranged one on the longitudinal median line of the flrebox and hereinafter referred to as the center siphon, and one spaced laterally at each side thereof and hereinafter referred to as the side siphons. All three siphons are substantially alike. In general, each siphon I8 is a hollow water steaming and circulating element having ends that open through certain sheets of the flrebox at different elevations as will later appear. When the nrebox is a relatively narrow one and only one siphon is employed therein, then such a siphon is disposed in the longitudinal median plane of the firebox and the boiler as a whole.

The improved siphon includes a nat hollow body I9 formed to provide relatively deep, front and rear end compartments or chambers 28 and 2I respectively separated by an intermediate compartment 22 of less depth. The body includes laterally spaced side walls 23-23 and transversely rounded front and rear end walls 24 and 25 respectively. The said side and end walls are flared outwardly around the entire top end of the body to provide a laterally extending flange 26. This fiange is fitted and welded in operative relation with respect to an associated longitudinal opening in the crown sheet 6. Thus the open top end of the body provides a common discharge for all three compartments 20, 2I and 22 respectively, of the siphon body, into the steam and water space of the boiler above the crown sheet.

The front wall 24 of the body is disposed at a relatively steep angle extending downwardly and rearwardly from the crown sheet and provides but a relatively small amount of overhang for this end of the body. The rear wall 25 of the body is disposed at relatively steep angle, substantially the opposite of that of the front wall, and extends downwardly and forwardly to merge into a rounded corner or nose 21.

Associated with said rear compartment of the siphon body is a downwardly and forwardly extending tubular inlet neck 28 of substantial length. The front end of said neck is anchored in a flexible diaphragm 29 preferably flanged up from the top portion of the inner front throat sheet 9 of the firebox. The inlet neck 28 is of a diameter greater than the spacing between the side walls 23-23 of the body and the upper rear end of said neck merges into the rear end of the body as a bulge 28a. that extends around the corner or nose 21 as best appears in Fig. 1.

The bottom portion of the front compartment 20 is formed as a stub-like tubular extension 30 disposed axially above and substantially parallel with the neck 28. This extension has a diameter substantially coinciding with the spacing between extremity of said other end is shown as being.

welded in an opening 32 formed in the top side of the inlet neck 28 to receive the same.

In Fig. 4, the extremity of said curved end of the neck or tube is shown as being welded in a diaphragm 33, flanged upwardly from an integral part of the neck 28. In Fig. 5 this diaphragm, which is indicated at 33a is made integral with an appropriately curved flange 33h which is welded in a matching opening in the top side of the inlet neck 28. In Fig. 6, the extremity of said end is shown as extending partway into the inlet neck 28 and there formed as a scoop or delector 3Ia, better to direct water into the auxiliary inlet tube or neck 3 I.

Fig. 7 illustrates a modified form of construction of that part of the inlet neck 28 that is attached in the throat sheet and which receives the inlet end of the auxiliary neck or tube 3 I. In Fig. '1, the inlet end portion 28.1: of the inlet neck is of a diameter enlarged with respect to the remainder of said neck and this enlarged inlet end portion is provided with a flange to receive the associated end of the inlet tube 3I. This arrangement permits of a better equalization of the volume of Water, delivered to the front and rear end chambers of each associated siphon body.

Preferably the auxiliary inlet tube 3I, when made separate from the remainder of the siphon structure described, is formed from a piece ofseamless tubing. By making the inlet tube 3| as a part separate from the remainder of the siphon and by using tubing of lesser diameter than the neck, said inlet tube is easier to bend or form to the desired shape.

The main inlet neck 28 has that downward and forward inclination desired in a fire arch. When such an arch is desired in a firebox having three siphons installed therein as best appears in Fig. 2, then said arch is made up of two side rows of brick 34 and two intermediate rows of brick 35. The lateral margins of both rows of intermediate brick are made for a good sealing engagement upon opposite sides of the inlet tube or neck 28 of the center siphon and upon those sides of the neck or tube 28 of the side siphons which face toward the center siphon. The inner margins of the brick 34 in the side rows are formed to engage upon the necks 28 of the side siphons while the outer margins of said brick are made to engage against the side sheets 5 of the rebox for support.

It is to be noted from Fig. 2 that the spacing between the brick in the side and intermediate rows 34 and 35 thereof, is less than the width of the body, and, therefore, less than the diameter of the auxiliary inlet neck 3| of the three siphons. Where the meeting faces of adjacent brick in said side and intermediate rows thereof are disposed in the plane of the auxiliary necks 3|, considered transversely of the firebox, corner parts 35a of said bricks are cut away as appears in Fig. 8. When the brick are arranged so that mid portions of brick in adjacent rows are disposed in said plane as before mentioned, center parts of one end of said brick are cut away as appears at 35h in Fig. 9.

It is apparent that while the body of each siphon has two inlet necks, they are so arranged that only one opening is required in the throat sheet 9 for each siphon. This effects a considerable saving in installation cost. While the inlet neck 28 is relatively large in diameter, it has such length as to impart to it the necessary flexibility. Also, while the auxiliary inlet neck 3l is short as compared With the inlet neck 28, it has a smaller diameter and includes a curved portion of relatively large radius that gives it the flexibility necessary to withstand service conditions.

It is apparent that the rear end chamber 2| of the body is disposed in such position that it is exposed to the higher temperature in the firebox and to the radiant heat of the re therein. However, as the inlet tube 28 has a greater diameter than the inlet neck 32, it will deliver a greater volume of water into said rear end chamber than is 'delivered into the front end chamber which is subject to lesser temperature with this arrangement. The rear compartment which is subjected to higher temperature cannot burn out because it receives an ample supply of water to olset said higher temperature.

In the operation of the siphon installation appearing in Figs. l and 2, water is taken into each neck 28 of the three siphons from the front throat I6. A part of this water passes up each auxiliary neck 3| into the front end chamber 20 of each siphon while the greater part passes up the remainder of the neck 28, into the rear end chamber 2| of each Siphon body. Water from both chambers enters the intermediate chamber 22 of each siphon so that the hollow body of each Siphon is completely filled with Water. Due to the action produced by the siphons, water is discharged from each one thereof through the crown sheet with a fountain action. Therefore, it is assured that the crown sheet is always flooded even under low water levels in the boiler.

In the manufacture of the siphon, that end of the neck 28 forwardly beyond the auxiliary neck, will have such length as to adapt its installation in a firebox of considerable length. For shorter reboxes, portions of said end of the neck may be cut off so that the siphons may be readily made to t said shorter reboxes.

While in describing the invention, I have referred in detail to the form, arrangement and construction of the parts involved, the same is to be considered only in the illustrative sense so that I do not wish to be limited thereto except as may be specilically set forth in the appended claims.

I claim as my invention:

l. In a locomotive boiler rebox, water steaming and circulating means therein, a body p0rtion and a downwardly and forwardly extending inlet neck therefor in communication with the water space of the boiler, said means including a second body portion spaced above said inlet neck at least in part, an inlet neck for said second body portion, opening into the rst mentioned inlet neck, a brick arch in the firebox comprisinga plurality of rows of brick having adjacent ends supported at least in part on the rst mentioned inlet neck and being accommodated by the spacing of the second body portion above the first mentioned inlet neck, certain of the brick being formed to pass about that part of the second mentioned inlet neck where it opens into the rst mentioned one.

2. A thermic siphon for use in a locomotive boiler rebox embodying therein a llat elongated hollow body comprising spaced apart sides and ends formed to provide relatively deep front and rear compartments in communication with each other, the two compartments having a common discharge at the upper ends into the boiler, a downwardly and forwardly extending tubular inlet neck of substantial length and of a diameter

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