US1987116A

US1987116A - Heat exchange apparatus

Info

Publication number: US1987116A
Application number: US688549A
Authority: US
Inventors: Charles H Leach
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-09-08
Filing date: 1933-09-08
Publication date: 1935-01-08
Anticipated expiration: 1952-01-08

Description

Jan. 8, 1935. c. 1-1. LEACH HEAT EXCHANGE APPARATUS 2 Sheet-Sheet 1 Filed Sept. 8, 19 53 FA w Jan. 8, 1935. c. H. LEACH HEAT EXCHANGE APPARATUS Filed Sept. 8, 1933 2 Sheets-Sheet 2 Patented Jan. 8,1935

PATENT OFFICE-Q BEAT EXCHANGE APPARATUS Charles H. Leach, Roselle, N. J.

September 8, 1933, Serial No. 688,549 14 Claims. (01. 257-5223) Application The present invention relates to heat exchange apparatus, and more particularly to tubular apparatus of this character designed for the cooling and condensation of hot oil vapors. j

The object of the invention is to improve and simplify tubular heat exchangers in which the heat exchange tubing is supported from a fixed support surmountedby an enclosing shell and providing for the access of cooling liquid to. the interiorof the tubes. v

With this and other objects in view, the va rious features of the invention consist in certain novel features of construction, combinations and arrangements of parts hereinafter described and claimed, the advantages of which will be obvious to those skilled in the art'from the following description.

In the accompanying drawings illustrating the preferred form of the invention, Fig. 1 represents an elevation in section-of a heat exchanger embodying the features of the invention; Figs. 2

and 3 are details illustrating the return header construction; Fig. A is a detail illustrating a modified form of onstruction for forming the liquid passages; g. 5 is a bottom plan view of the exchanger showing the removable cover plates; and Fig. 6 is a bottom plan view of the construction shown generally in Fig. 4,. but with separate liquid passages to make provision for in dependent volumes of charge oil.

Referring to the illustrated embodiment of the invention, the unitary tube support comprises a circular supporting ring 10 having an annular and inwardly projecting partition and tube support 12. To this partition are connected the lower ends of a series of tube lengths indicated at 14, each of which comprises a plurality of tubes 16 connected by return bend headers 18. With this construction each continuous length of tubing withits plurality of return bends forms a. system in the form of a flat zig-zag coil for the circulation of liquid therethrough, the liquid entering at the left from the chamber 20, and emerging at the right into the chamber 22, these chambers being formed at the opposite side of the partition 12 from the vapor space, and being sealed from one another, as will be evident to those skilled in the art.

Any considerable number of coils may be employed, depending upon the amount of heat exchange surface desired and the restrictions imposed by the space. In the elevation shown in Fig. 1 only one continuous length of tubing or coil has been illustrated for purposes of sim-' plicity.

Each of the

liquid passages

20 and 22 formed in the partition are of suflicient area to communicate with'the entering or leaving ends of the entire series of tubelengths, andathe passages are closed by detachable cover members ii'l and 26,

respectively, these cover members being provided with

liquid nozzles

28 and 30, as indicated. Removal of the cover members, which are coextensive with the passages, completelyexposes the lower tube ends for re-tubing or replacement. The tubes of each individual series of return bends in order to provide -a continuous lengthare connected by the return headers 18, which are shown indetail in Figs. 2 and 3. These return headers may be formed as a forged member 40, having a return passage 42 having the tube endsirolled thereinto at 43. The header is provided with two closures 45, beneath each-tube end, which normally seal the interior of the header, but which upon removalafford access to'thev lower tube ends. Each of these closures comprises a sealing disk 46 which is forced into and seals the passage 47 by an abutment screw 48, threaded in a shouldered 'sleeve 50, and upon' tightening within the sleeve serving to thrust the disk into sealing position. By loosening the abutment screw and dropping the disk and by turning of the sleeve 50, it may be removed from the ears 52 and the entire assembly withdrawn. This sealing construction is in commercial use, and forms no part of the present invention per 'se. It does provide an effective method of obtaining access to the tube ends for replacement or tightening when desired. I

The interior of the tube support is sealed by a detachable circular cover 60, connected to the inwardly extending flange 62 of the partition 12, as indicated. This coverlis provided with arib' 64,-and forms two

condensate basins

66 and 68 which are drained at 70 and 72, respectively. The unitary support is provided with sloping walls which tend to shed condensate from about the lower tube ends into the basins, and thus avoid excessive corrosion. The support is surmounted by a vapor nozzle annulus 74, having an I inlet vapor nozzle 76 and an outlet nozzle '18. The inlet nozzle is provided with a target 80 to avoid .direct impingement of the vapor upon the immediate tubes. Both the tube support and the nozzle annulus are provided with contiguous partition sections 82 and 84, which form in effect'a continuous partition to provide more than one va-' por pass and shed'condensate into the basins, therebeneath. Surmounting the nozzle annulus is a closed top shell coverof cylindrical form 86, detachably connected to the annulus and removable therefrom to expose the tubes. An upper baflle section- 88 associated with the shell provides a continuation of the lower sections 82 and 84 to complete the separation between vapor passes. I The passage of vapor through-thetube region above the entering nozzle region is baiiled=by an assembly consisting of semi-circular rings 90' mounted upon distance rods 92, which in turn are supported froma ledge 94 formed on the nozzle round the tube bundles and baille the spacebe tween the tube bundles and the shell. The assemblies are also provided with cross battles 96, which baflle the space between the tubes themselves. It will be evident that with this construction shell removal may be accomplished without interfering with the baflle assembly.

The present apparatus has several advantages, as strain upon the tubesis minimized due to the method of support, free space is provided for entering vapor about the lower tube ends to avoid excessive velocity impact and consequent corrosion, the tube surface above the entering region is made most effective by baiiiing, and collection of condensate ispromoted and corrosion of tubes by condensate minimized by shedding condensate away from the lower tube ends into the central basins. Furthermore, replacement of corroded or worn tubes is facilitated by easy access to the fixed supports and also to individual tube lengths through the return headers. It will be evident that with this construction individual tube lengths may be replaced without requiring replacement of an entire coil.

Fig. 4 illustrates a slightly modified form of construction in which the unitary tube support 10 is provided with an integrally closed liquid passage 100, having a conduit'102 tapped thereinto. In this construction access to the lower tube ends is obtained through a series of detachable closure members 104 similar to those described in Figs. 2 and 3, a separate closure being located in line with and below each tube end. The central cover member 60, as shown in Fig. 1, is employed without change; This construction has the advantage that it virtually eliminates all high pressure joints. This will be understood when it is realized that the cooling liquid in this type of apparatus is ordinarily supplied under very substantial pressure, and is raised to a temperature at which it will ordinarily ignite when exposed to atmosphere. The elimination in whole or in-part of sealed joints from this high pressure system is desirable.

, The present .apparatus is admirably suited for I the employment of two or more cooling mediums which may be caused to flow in independent but parallel, paths through each coil. This feature is of particular importance where it is desiredto raise the temperature of a charge of crude oil for cracking purposes, and where for various reasons it is both necessary and desirable to maintain difierent charges entirely independent. Nevertheless, both of these charges may be raised in temperature in a heat exchange unit and receive heat from the same oil vapor which is cooled and condensed thereby. Obviously the maintenance of separated and parallel circuits for the liquid cooling medium such as charge oil is not possible in a tubular exchanger except with separate and independent series of tubes.

As indicated in Fig. 6, I am enabled to accomplish this useful result in the present invention by simply dividing the liquid chambers 100 of Fig. 4 each into two chambers, which may be in- I dicated as 110 and 112, and 114 and 116, respectively. Each of the

chambers

110 and 112 is pro-- vided with an inlet pipe .118 and 120, and the cor-- responding chambers at the outlet side-114 and 116. are provided with separate outlets 122 and 124.- The separation of the chambers is accomplished by providing mid-partitions 126 and 128,

one in each cored-outpassage. Withlthis nstruction one type of charge oil may be delivered to the chamber 110 through the inlet 118, and from this chamber will flow through all of the coils connectedtherewith, being delivered therefrom to the chamber 114 and thence discharged by the pipe 122. A second and different type of cooling medium may in like manner he passed through the path provided by the pipe 120, chamber 112, the coil connected therewith, the chamber 11d and outlet pipe 124.

This type of operation, where it is desired to pro-heat or raise the temperature of two or more types of charge, is preferable to the utilization of two or more liquid cooling paths in series, as the longer path through which each charge flows comprising the entire series of tubes produces a greater differential head and a greater tendency to force the oil continuously through each series. Obviously the liquid cooling paths might be further multiplied by additional division of the chambers into a larger number of units. In fact, if so desired each separate coil might constitute an independent circuit for the flow of liquid medium therethrough.

It will be understood that with the present invention dismantling and clean-out of the interior of the exchanger is facilitated by the employment of separate return headers each connected to a single series, as upon removal of the enclosing shell the tube series at opposite ends -may be separated for the introduction of a cleaning tool and thorough removal of solid residue, the tubes themselves being capable of the distortion necessary to procure this separation. Furthermore, the removal of the domed cover member 60 from beneath the tube series permits solid residue to be diverted outwardly through the bottom of the apparatus and removed by flushing or otherwise.

port and designed to provide a closed vapor space exteriorly of the tubing.

.2. Heat exchange apparatus comprising a tube support in the form of a ring, a length of" tubing having a series of return bends, connected to the support at opposite ends and communicating with liquid passages at the opposite sides thereof, and detachable means for sealing the passages designed upon removal to permit access to the connected tube ends for replacement or tightening. k

3. Heat exchange apparatus comprising a tubesupporting ring having a, central portion in free communication with the vapor region thereabove, a shell connected with the support, liquid passages located upon the opposite side of the tube support from the vapor region and adjacent the margin of the" support, heat exchange tubing comprising a series of straight rims connected by return bends connected at opposite ends to thesupport and. communicating interior ly'with the liquid passages, and detachable means sealing the passage designed to permit access to the connected tube end when removed.

5. Heat exchange apparatus comprising a tubesupporting ring having an inwardly projecting ledge, a condensate basin located below the ledge and inwardly thereof, a length of heat exchange tubing in the form of a series of return bends having opposite free ends connected to the ledge at opposite sides of the support, a liquid passage communicating with the interior of each connected end, detachable means for sealing the passage designed to permit access to the connected tube end when removed, and a detachable cover connected to the support and designed to form the depressed central basin portion.

6. Heat exchange apparatus comprising a tubesupporting ring having an inwardly projecting ledge and a central condensate basin located below the ledge and inwardly thereof, a length of heat exchange tubing in theform of a series of return bends having opposite free ends con nected to the ledge at opposite sides of the support, a liquid passage communicating with the interior of each connected end, detachable means for sealing the passage designed to permit access to the connected tube end when removed, and a detachable cover member having a partition rib designed to provide more than one depressed condensate basin.

7. Heat exchange apparatus comprising a tubesupporting ring embodying a liquid vapor partition, a length of tubing having a series of return bends connected at opposite free ends to the supporting ring and projecting into the vapor space, liquid passages on the opposite side of the support communicating with the interior of the free ends of the tubing, a shell enclosing the vapor space and detachably connected with the support, a vapor inlet nozzle communicating with the shell, and means for baffling the vapor space exteriorly of the tubes beyond the vapor inlet.

8. Heat exchange apparatus comprising a tubesupporting ring embodying a liquid vapor partition, a length of tubing having a series of return bends connected at opposite free ends to the supporting ring and projecting into the vapor space, liquid passages on the opposite side of the support communicating with the interior of the free ends of the tubing, a shell enclosing the vapor space and detachably connected with the support, a vapor inlet nozzle communicating with the shell, a vapor target located in the path of incoming vapors to avoid direct impingement on the heat exchange tubing, and means for producing more than one vapor pass through the interior of the shell, v

9. Heat exchange apparatus comprising a unitary supporting. annulus having an inwardly projecting flange to provide a tube sheet, a length ofheat exchange tubing having a series of return bends connected at its free ends to the flange at opposite sides of the annulus and with the intermediate bends lying therebetween and supported thereby, a condensate basin formed centrally of the support and between the connected ends, a shell enclosing the vapor space about the exterior of the tubing, and liquid passages communicating with the interior of the tubing and sealed from the vapor space by the tube flange.

10. Heat exchange apparatus comprising a unitary supporting annulus having an inwardly projecting flange to provide a tube sheet, a length of heat exchange tubing having a series of return bends connected at its free ends to the flange at oppositesides of the annulus and with the intermediate bends lying therebetween and supported thereby, a condensate basin formed centrally of the support and between the connected ends, a shell enclosing the vapor space about the exterior of the tubing, liquid passages of limited area with respect to the area of the annulus in communication with the connected ends of the tubing, and detachable cover members co-extensive with the passages and serving to seal the passages when connected to the supporting member.

11. Heat exchange apparatus comprising a tube-supporting annulus having an internally projecting flange with a depressed condensate basin therewithin, a length of heat exchange tubing consisting of a series of return bends connected at free ends to the flange at opp ite sides of the annulus and with the intermediate portions above the condensate basin, liquid passages formed at the opposite side of the flange and sealed thereby from the vapor space, means for detachably closing the passages, and a shell surrounding the tube to provide a vapor space and detachably connected with the annulus.

12. Heat exchange apparatus comprising a tube-supporting annulus having an inwardly projecting tube flange, liquid passages formed completely in the annulus and sealed from the vapor space, heat exchange tubing connected with the flange and communicating wtih the liquid passages, and removable means for hermetically sealing the passages in alignment with each tube end to permit access to the tube on removal.

13. Heat exchange apparatus comprising a tube-supporting ring, more than one series of heat exchange tubing, each series comprising a series of'flat, loops supported by the ring at opposite ends, separate and independent liquid passages communicating with different series of loops at entering and exit points to provide for more than one cooling fluid in'parallel flow, an enclosing shell surrounding the tube series, and means for admitting vapor to the shell. v

14. Heat exchange apparatus comprising a supporting annulus having an inwardly projecting tube-supporting flange, a depressed and generally central condensate basin, the surface of the flange sloping downwardly to discharge condensate by gravity into the basin, heat exchange 1 tubing connected to the flange at opposite sidesof the annulus and having intermediate loops supported thereby, a removable cover forming the depressed condensate basin, a liquid passage formed at the opposite sideof the flange communicating with the interior of the heat exchange tubing, a shell enclosing the exterior of the tubing, and means for admitting vapor tothe shell.

' CHARLES H. LEACH.