US3662583A - Transition members - Google Patents

Abstract

A round tubular work-piece of substantially uniform diameter and wall-thickness is forged from within, by a particularly shaped spud or mandrel, to obtain a nozzle or connector element having therewithin a substantially uniform cross-sectional area which changes in shape from round to oblong whereby it may uniformly supply fluid to a larger number of tubes or the like which are arranged in spaced parallelism with respect to each other.

Description

United States Patent 1151 3,662,583

Moore, Sr. [451 May 16, 1972 54] TRANSITION MEMBERS 3,354,695 11/1967 Szente ..72/37o 3,452,576 7/1969 Wilson....

[72] Inventor: Charles H. Moore, Sr., 645 Matanzas Ct.,

Fort Myers Beach, Fla. 33931 [22] Filed: Feb. 6, 1970 [21] Appl. No.: 9,324

[52] U.S. Cl. ..72/370, 29/157 C [51] Int. Cl ..B21d 41/00 [58] Field of Search ..72/370, 393, 398; 113/118 U,

113/118 DD; 29/157, 157 C, 157.5, DlG.4l, 183.5,

[56] References Cited UNITED STATES PATENTS 2,181,927 12/1939 Townsend ..29/DIG. 41

Primary Examiner-Lowell A. Larson Attorney-Robert U. Geib, Jr.

A round tubular work-piece of substantially uniform diameter and wall-thickness is forged from within, by a particularly shaped spud or mandrel, to obtain a nozzle or connector ele- ABSTRACT ment having therewithin a substantially uniform cross-sectional area which changes in shape from round to oblong whereby it may uniformly supply fluid to a larger number of tubes or the like which are arranged in spaced parallelism with respect to each other.

4 Claims, 6 Drawing Figures PATENTEDMAYIS I972 3.662.583

SHEET 1 [1F 3 IINVENTOR ['M924 5-5, ff M0025 ATTORNEY TRANSITION MEMBERS The present invention relates to transition members or connector elements through which fluids are transmitted while changing from a round cross-sectional area to one which is substantially oblong.

While not limited thereto, the invention has particular application to transition nozzles which are used in the boxheaders of air-cooled heat exchangers.

It is, of course, well-known that air-cooled heat exchangers have many advantages over conventional liquid-cooled heat exchangers because the economics and maintenance'costs are much lower due to the fact that cooling towers, pumps, extensive piping and water sources are eliminated.

Ordinarily, air-cooled heat exchangers comprise finned tubes which are welded into a baffled box-header, as are also the inlet and outlet nozzles. As the size of the box-header increases, the cost of the heat exchanger increases but its efficiency decreases; due, of course, to the addition of material and the welding thereof and the fact that the process fluid in the header is not being cooled.

In order to reduce the size of the header for the heat exchanger, resort was had to transition nozzles which at one end are circular to fit a circular pipe which feeds or exhausts the cooling fluid and which, at its other end is oblong in cross section to provide a wider spread for covering an area which includes a larger number of the heat-exchanger tubes which are arranged in conventional spaced parallelism with respect to each other.

Prior to the present invention, two types of transition nozzles have been introduced to the market; one of which is in the form of a casting while the other is a welded fabrication.

In the case of a casting there are the usual objections as to strength, blow holes and weldability; while a welded fabrication of the shape desired involves more metal and the additional cost of welding the components together.

Further, the cast transition nozzles which are presently available on the market provide cross-sectional areas at the round and oblong ends which are uneven and introduce undesirable turbulence of the fluid moving therethrough, whereas the welded fabrication not only results in too much increase in cross-sectional area between the round and oblong ends, but the two different component elements which are welded together sometimes fail at the welds.

Accordingly, the present invention seeks to provide a transition nozzle or connector which is free of the objections referred to in that it eliminates or very materially reduces turbulence therewithin, is durable in service, and is easy and inexpensive to manufacture.

Another object is to provide a transition nozzle or connecting member which, due to its construction, may be welded to a box-header of narrower width and lighter plate than would otherwise be the case, thereby resulting in further economies.

Still another object is the provision of a transition nozzle which is possessed of the desirable characteristics set forth hereinabove and which may be produced from a wide variety of metals rather than being confined to carbon steel as in the case of certain of the devices of the prior art.

The foregoing and other objectives and advantages will become more readily apparent after referring to the following description and the annexed drawings wherein like numbers refer to like parts, and wherein:

FIG. 1 is a perspective which represents a transition nozzle or connector member which embodies the teachings of the invention;

FIG. 2 is a vertical sectional elevational view taken along the axis of the transition nozzle of FIG. 1 and illustrating the transition of the cross section area therewithin from circular to the full length of the oblong;

FIG. 3 is a view which is similar in nature to the view of FIG. 2, but taken at a 90 angle with respect thereto, whereby it illustrates the narrowest portion of the oblong section;

FIG. 4 is an end view of the smallest end of the spud or mandrel with which the transition from a circular to oblong crosssectional area is obtained;

FIG. 5 is an elevational view illustrating the taper of the spud or mandrel of FIG. 4; and

FIG. 6 is a chart which illustrates the changes in the relative dimensions of the transition nozzles of the invention in sizes at the circular end of 6 inches, 8 inches, 10 inches and 12 inches, and adapted for pressures per square inch of pounds, 300 pounds, 600 pounds, 900 pounds, 1,500 pounds and 2,500 pounds respectively, the nozzles ranging in weight from approximately 51 pounds for the 6-inch size adapted for pressures of 150 pounds per square inch to approximately 1,571 pounds for the 12-inch size adapted for pressures of 2,500 pounds per square inch.

Referring more particularly to the drawings, the numeral 2 generally designates a typical transition nozzle which has been made in accordance with the teachings of the invention, the same comprising a tubular portion 3 which is provided at its circular end 4 with an integral welding flange 5, the opposite end thereof being oblong in shape as indicated at 6.

It will be understood by those skilled in the art that the invention is equally applicable to transition nozzles which are produced without a welding flange, i.e. stub type, in which case such a flange, if desired, may be subsequently attached.

In FIG. 1, as well as in FIGS. 2 and 3, the internal diameter of the circular (and flanged) end 4 of the transition nozzle 2 is indicated at B; and in the case of an 8-inch size will be approximately 7.625 inches with a circumference of approximately 23,947 inches. The major internal dimension C of the oblong end 6 of this 8-inch transition nozzle is approximately 12 9/32 inches with the minor dimension D of approximately 4 inches; representing an increase in the internal circumference of the nozzle from round to oblong which amounts to 5.1742 inches.

For the dimensions referred to immediately hereinbefore the cross-sectional area of the interior of the round end of the transition nozzle 2 is approximately 45.664 square inches as compared with a cross-sectional area of approximately 45 .691 square inches for the interior of the oblong end. Thus, rather than there being a reduction in cross-sectional area as between the circular end of the nozzle and the oblong end thereof, as in the case of some of the devices of the prior art and which results in pressure drop, turbulence, etc. they are substantially the same.

In the case of the present invention, the cross-sectional area of the oblong end of the transition nozzle is never appreciably less than that of the circular end; and it is forthis reason that pressure drop and turbulence are eliminated.

The method of producing the improved transition nozzle comprises heating a tubular work-piece of suitable metal,

preferably of substantially uniform diameter and wallthickness, to forging temperature; positioning the same on a block; and pressing into the interior thereof a spud or mandrel possessing exterior surface portions such as will produce the conformation described; and while leaving the exterior of the work-piece unconfined, and free to be moved outwardly to the extent required.

Referring to FIG. 5, the mandrel or spud of the invention is indicated at 10 and shown as comprising a main body portion which is substantially triangular in elevation and provided on each side with a surface 12 which is relatively flat, tapers from top to bottom, and which terminates at its side edges in an outwardly bowed or curved portion 14 which likewise extends from top to bottom.

At the bottom of the main body portion of the mandrel 10 there is a relatively short extension, generally indicated at 16, having relatively flat sides 18 which are in substantially the same plane as the aforementioned flat surfaces 12 and which terminate at their side edges with outwardly bowed or curved portions 20 which are pitched from axes which extend substantially vertically. That is, the outwardly bowed or curved portions 20 of the relatively short extension 16 have little or no downward taper, as distinguished from the extensive downward tapering of the outwardly bowed or curved portions at the side edges 14 of the main body portion 12 of the mandrel.

Also to be noted is the fact that the thickness T of the mandrel is approximately equal to the radius of the inside diameter of the round end of the transition nozzle 2; which, for the 8-inch (diameter) example previously mentioned would be approximately 4 inches.

From the foregoing it will be appreciated that the transition member of the invention not only eliminates or very materially reduces pressure drop and turbulence as between the circular end and the oval or substantially oblong end; but by reducing the width at the substantially oblong end to approximately one-half of the diameter of the round end it may at the substantially oblong end be welded to a box-header which is very much narrower than would otherwise be the case. For the given example of an 8-inch nozzle, the box-header need only be 8 inches wide and formed of plate of l-inch thickness to accommodate the substantially oblong end of the nozzle which is 12 9/32 inches by approximately 4 inches. Distinguish, on the other hand, a transition nozzle having an 8-inch circular end for attachment to the box-header which would require, for welding purposes, a box-header of 12-inch width and formed of plate which, for reenforcement purposes, would have to be 1 54 inches thick.

As previously pointed out, this is one of the numerous advantages of the present invention, along with substantial elimination of pressure drop and turbulence, durability in service, etc.

lt will, of course, be understood that prior to the actual attachment of the substantially oblong or oval end of the nozzle to the box-header it will be bevelled in the manner well-known in the art.

The term oblong as used herein is intended to define a structure which in cross section possesses two substantially flat and parallel side-walls with two semi-circular ends the radius of which is approximately one-half of the overall thickness of the structure of the aforementioned side-walls.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:

l. The method of obtaining a heavy-duty forged metal transition member for transmitting fluids through a passage which gradually changes from round cross-sectional area to substantially oblong cross-sectional area such as a nozzle for a heat-exchanger which method essentially comprises heating a round metallic tubular work-piece to forging temperature;

applying within the work-piece, and commencing at one end thereof, diametrically opposed expanding forces which are confined to limit circumferentially extending areas of the inner surface of the work-piece;

continuing the application of the diametrically opposed expanding forces from within the work-piece while moving the same longitudinally toward the other end of the workpiece; and, finally,

shaping the last mentioned end of the work-piece to provide a circular opening therein.

2. The method of claim 1 wherein the cross-sectional area of the oblong end of the interior of the finished work-piece is at least as large as the cross-sectional area of the interior of the circular end thereof.

3. The method of claim 1 wherein the oblong section of the finished work-piece comprises two opposite major areas which are substantially straight and in spaced parallelism with respect to each other.

4. The method of claim 1 wherein the oblong section of the finished work-piece comprises two parallel and substantially straight side areas with two semi-circular ends the radius of which is approximately one-half of the overall thickness of the transition member at the two substantially straight side areas.

Claims (4)

1. The method of obtaining a heavy-duty forged metal transition member for transmitting fluids through a passage which gradually changes from round cross-sectional area to substantially oblong cross-sectional area such as a nozzle for a heat-exchanger which method essentially comprises heating a round metallic tubular work-piece to forging temperature; applying within the work-piece, and commencing at one end thereof, diametrically opposed expanding forces which aRe confined to limit circumferentially extending areas of the inner surface of the work-piece; continuing the application of the diametrically opposed expanding forces from within the work-piece while moving the same longitudinally toward the other end of the work-piece; and, finally, shaping the last mentioned end of the work-piece to provide a circular opening therein.

2. The method of claim 1 wherein the cross-sectional area of the oblong end of the interior of the finished work-piece is at least as large as the cross-sectional area of the interior of the circular end thereof.

3. The method of claim 1 wherein the oblong section of the finished work-piece comprises two opposite major areas which are substantially straight and in spaced parallelism with respect to each other.

4. The method of claim 1 wherein the oblong section of the finished work-piece comprises two parallel and substantially straight side areas with two semi-circular ends the radius of which is approximately one-half of the overall thickness of the transition member at the two substantially straight side areas.

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