US1997194A - Heat exchange apparatus - Google Patents

Description

April 1935- 'c. H. LEACH 1,997,194 I I HEAT EXCHANGE APPARATUS Filed Aug. 4, 1931 3 Sheets-Sheet 1 5 50 64 2:6 lI ibzew' 66 do 54 52 jvenior April 9, 1935.

C. H. LEACH HEAT EXCHANGE APPARATUS F iled Aug. 4, 1931 .3 Sheets-Sheet 2 ILveni'or April 1935- c. H. LEACH 1,997,194

HEAT EXCHANGE APPARATUS Filed Aug. 4, 1931 3 Sheets-Sheet 3 Patented Apr. 9 1935 UNITED STATES PATENT OFFICE HEAT EXCHANGE APPARATUS Charles H. Leach,R.oselle, N. J. Application. sums 4, 1931, Serial No. 554,993

a 9 Claims. (01. 257-223) The present invention relates to heat exchange apparatus, and more particularly to apparatus of this type employed for transferring heat from oil vapor during the condensation thereof to cooling fluids, whichmay be charge oil before delivery to the cracking stills. l

The purpose and object of the present'invention is to provide a simple and efficient type of heat exchange apparatus particularly adapted for oil refining operations, and having particular capacity for eflicient operation employing cooling fluid under relatively high pressures.

With high pressures and corresponding tern peratures of fluid oil, the necessity for effectively sealing the fluid chambers against leakage to atmosphere under all conditions is vitally necessary, as otherwise incipient leakage may rapidly develop disastrous consequences. According to the present invention the apparatus, due to its structural characteristics, has capacity. for resisting leakage under all conditions of operation and successfully resisting unit pressures on the order of 1500 to 2000 lbs. without leakage. 5

With this and other objects in view, the .various 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 a longitudinal section in elevation of my im-' proved apparatus; Fig. 2 is a bottom plan view with the cover plate removed of the apparatus shown in Fig. 1; Fig. 3 is a detail illustrating a section of the channel ring providing the tube sheet with condensate basins and cooling fluid passages at opposite sides; Figs. 4 and 5 illustrate sential aspects to apparatus previously developed 60. by me and covered in copending' applications. This apparatus comprises generally a channel ring indicated at In, to the upper portion of which is secured a nozzle ring I2 having 'vapor inlet and outlet nozzles l4 and l6. The nozzle ring-and 5 channel ring are detachably connected through contacting flanges l8 and securing bolts 20. Connected'to the upper portion of the nozzle ring is an enclosing tubular shell 22, surmounted by a domed cover 24 detachably connected to the shell by bolts 26. Supported within the shell 5 and connected at their lower ends to an integral tube sheet 30 is a series of'tubes 32, which in the illustrated embodiment of the invention are segregated in two banks 34 and 36, respectively. All of the tubes, asindicatedin Fig. 1, are connected 10 at their lower ends into the stationary tube sheet 30. At their upper ends each bank of tubes is separately connected with a floating head 38, allowing provision for independent expansion and contraction of each tube bank. The interior of the shell is divided into two vapor passes by a longitudinal baflle 40, which extends upwardly from an integral abutment 42 to the region between the floating heads, as indicated. The longitudinal baflle is provided with an opening 44, which provides a vapor passage for intercommunication between the two banks of tubes.

With this construction, as will be evident to those skilled in the art, either the domed cover 24 or the tubular shell 22 and connected nozzle 25 ring l2 may be disassembled and removed from the channel ring without interference with the tube banks, the longitudinal baflle 40 being capable of removal with the shell, passing upwardly between the floating heads.

As will be further evident to those skilled in the art, the vapor passes longitudinally of the tubes and exteriorly thereof, being cooled and condensed by contact therewith. Cooling fluid passes interiorly of the tubes-in a lengthwise direction, this cooling ,fluid passing twice through each tube bank, the direction of flow being reversed in the chamber 46 formed in each floating head and directed from one bank to the next in the passages formed beneath the tube sheet, as will be more fully describedhereinafter.

. In the so-called high pressure type of apparatus, the cooling fluid flow is passed through the heat exchanger under. comparatively high pressures, which may be on the order of 1,000 to 2,000 lbs. per square inch. Although the pressure drop through the apparatus is normally small, perhaps not exceeding 10 or 15 Has, the pressure 1 difierential between the interior of the apparatus and atmosphere is very great, and requires exceeding care in the structure of the apparatus to avoid difliculties incident to even a slight leakage of the hot oil to atmosphere.

I have devised a construction which, owing to its characteristic arrangement, permits the tight sealing of the fluid chambers throughout all .regions of possible leakage. For the accomplishment of this purpose I provide an integral channel ring Ill having an intermediate web which forms a tube sheet with condensate basins provided above the tube sheet and provision for the-formation of fluid passages or chambers below the tube sheet. This integral channel ring may be formed from a flat steel billet of requisite thickness indiameter, having portions intermediate the outer periphery either hogged or routed out to form the condensate basins above the web with the intermediate partition 42, and fluid chambers below the web with an intermediate support to be more fully described herein- I after. The bottom face ofthe channel ring and the corresponding face of the intermediate sup-' porting partition are accurately faced or machined in one operation to provide an accurate.

tending to separate it. I also insure that the cover securing bolts affording connection with the intermediate support are disposed in the lower part of the support well below the active path of flow of the hot fluid, and so far as possible removed from temperature changes dictated by changes in the fluid itself. By virtue of thiscon struction I tend to equalize the expansion and contraction of the outer peripheral and intermediate securing bolts for the purpose of maintaining at all times a uniform tension upon these bolts. Active temperature fluctuations are furthermore minimized by providing a disk shaped gasket of asbestos or similar material disposed above the cover member and sealing. the

intermediate and peripheral joints through which leakage might otherwise occur about the bolts. This asbestos disk, which is preferably sheeted with steel at opposite sides, provides both an in-; sulating and sealing function, and causes thesecuring bolts to partake of external atmospheric conditions to a greater extent than temperature conditions imposed by the varying temperature of the hot oil. The metal covering of the asbestos disk may preferably be made of stainless steel or similar non-corrosive metal .to inhibit corrosion or erosion, and protect the insulating gasket from the action of the active ingredients contained in the charge oil or cooling fluid.

Upon reference to the drawings these features will be more clearly evident. The channel ring ID, as indicated, is provided with an intermediate integral web 30, forming the tube sheet and having the upstanding abutment 42 formed therein through hogging out of intermediate portions between the periphery and the abutment. 'Below the transverse web the channel ring is provided with a downwardly extending circumferential portion 50 and an intermediate supporting partition rib 52, all as indicated moreparticularly in Figs. 1', 2, and 3. The lower meeting faces of they circumferential portion 50 and intermediate por-' tion 52 are accurately machined, preferably at a single operation, toprovide a ,uniform support for'a flat cover member indicated at 54. The cover member 54 is rigidly connected tothe chan-' nel ring about the periphery thereof through securing bolts 56. This connection is augmented, as necessarily must be the case in high pressure units, by an intermediate line of supports comprising short stud bolts 58 threaded into the lower portion of therib- 52 at, and oi sufllcient length to extend downwardly through the cover member and project therethrough. The bolting connection is accomplished by cap nuts'52 which are threaded on tothe lower ends of the bolts below the cover and serve to'draw the cover rigidly against the meeting face of the partition 52. With this construction it willbe self-evident that both the outer peripheral bolts and the intermediate bolts are governed in temperature primarily by thetemperature of the flat cover.

an outer ring 10 and intermediate transverse par-' titions 12' extending thereacross and disposed at proper intervals. This ring corresponds in depth to the depth of the space provided by the circumferential portion 50, and is easily assembledtherewithin and held in place by assembly of the flat cover member. If desirable, although not- .necessary, the. ring, instead of being'assembled and held through contact with the cover member, may be welded within the channel ring I0. As will be more clearly evident from an inspection of Fig. 2 the intermediate supporting partition 52 doesnot extend completely across the lower portion of the channel ring, but terminates short thereof to providecircumferential grooves for the seating of thering assembly. Through the employment of this ring assembly in combination with the integral partition 52, the space below the tube sheet is divided into four chambers, communicating respectively with a portion of each tube bank, as indicated clearly in Fig. l. .The partition rib 52 is provided with fluid apertures or passages 14 above the stud bolts 55 for transferring fluid from the lower end of one tube bank to the lower end of the next adjacent bank, the partition 12 cooperating with the intermediate partition to prevent intercomniunication at their lower ends between different portions of the same tube bank, and thus cooperate with the upper chambers 45 to provide for two fluid passes interiorly of each bank, in a manner which will be obvious to those skilled in the art. 7

From the above description it will be evident that'the portions of the apparatus subjected to greatest pressures and affording the greatest opportunity for leakage are the portions sealing the fluid chambers, which are inevitably the detachable cover member with the peripheral and intermediate joints for attachment of the cover member to the channel -ring.- By providing an integral channel ring which is rigid, free from strains,-

and capable of avoiding distortion under unequal changes of temperature, the meeting faces for supporting the cover member are maintained in In addition to all of this, however, -I have found that sealing can be desirably augmented through the employment of a disk gasket, as more particularly indicated in Fig. 6, comprising essentially an asbestos sheet coveredon opposite sides and preferably completely enveloped by thin steel sheets formed thereover to provide a steel covered asbestos disk, capable of withstanding high tension strains but nevertheless being Sufflciently yielding to cushion and seal the parts at contacting points This disk also provides an ideal insulating medium for avoiding transfer of heat from the charge oil within the chambers downwardly through the cover member. As indicated more particularly in Fig. 6, the disk, which is shown at 88, is pierced at 82 with a series of openings for the reception of the intermediate securing bolts 58. When the disk is inserted at the lower portion of the channel ring, it seats at its outer periphery in a shoulder 84, formed in the channel ring, and the openings 82 register with the bolts 58. Thereafter, when the cover member is applied and the peripheral and intermediate securing bolts and' accompanying nuts properly connected and forced up with uniform tension, the sealing disk yields sufliciently to provide a tight joint and seal the areas about the intermediate bolts and within and adjacent to the peripheral bolts. Likewise the entire surface of the cover member adjacent the bottom of the fluid chambers is sealed from contact with the cooling fluid by the disk. Transfer of heat from the fluid to the outer portion of the channel ring is also inhibited by the separable fluid passage assembly 18 inserted therewithin. The sealing action of the disk about the periphery is preferably augmented by a ring gasket indicated at 86, which seats within a channel 88 formed in. the cover member, as indicated more particularly in Fig. 1. The corresponding tongue 98 on the lower face of the channel ring registers with the seating channel to complement sealing.

With this construction it will be evident, first that the active flow of hot charge oil throughout the region of the intermediate securing bolts is through the openings 14 from the lower end of one tube bank to the next and above the region of the bolts, the lower portion of the fluid chambers surrounding the partition 52 in the bolting region being filled with more or less stagnant oil. Furthermore, the intermediate bolts as well as the peripheral bolts, due to their location, partake of the temperature of the cover member rather than the portions of the apparatus in direct contact with excessively hot charge oil. Furthermore, the cover member which governs the temperature of the securing members is sealed from this oil, and is not accordingly elevated to excessively high temperatures. The net result of the construction is that owing to this construction auniform tensior Lcan initially be placed upon all of the securing bolts, and that thereafter this tension is not disturbed by unequal expansion and contraction of the bolts, which otherwise tend to cause a slacking off of the nuts with incipient leakage and resulting disastrous consequences. The particular type of disk gasket employed, namely asbestos covered with steel, also promotes safety, as even though incipient leakage may occur, the gasket will not be ruptured thereby and leakage will be confined to a slight bleeding or sweating rather than increasing in volume. The proper sealing and maintenance of a proper seal in high pressure heat exchangers for this purpose is all important, and without such proper sealing and maintenance under varying conditions of pressure and temperature the apparatus is wholly impractical, and the use of it may actually be fatal to life and limb.

As will be evident to those skilled in the art, vapor condensate caused by contact of vapor with the tube banks may be separately collected in the condensate chambers 90 and 92 formed in the channel ring, above the tube support, these-chamings 94 shown in Figs. 2 and 3. Cooling fluid is delivered to and removed from the chambers beneath the tube support through the passages 85 in communication therewith, also shown in Figs.

2 and 3, the heme assembly being provided with openings 95 which register with these openings when in position.

What is claimed is:

1. Heat exchange apparatus comprising a channel ring having a tube support, partitions forming fluid chambers below the tube support, a cover member detachably connected to the channel ring, and a metallic covered'insulating disk of asbestos or the like disposed above the cover member and clamped between the cover member and. channel ring to insulate the cover member from the hot fluid within the chambers.

2. Heat exchange apparatus comprising a channel ring having a tube support, an intermediate partition depending therefrom, a separate partition assembly inserted within the channel ring below the tube support cooperating'with the intermediate partition to direct the flow of fluid, a cover member, a series of peripheral bolting connections between the cover member and channel ring, and a series of intermediate bolting connections between the cover member and intermediate support. v

3. Heat exchange apparatus comprising a channel ring having a tube support, an intermediate partition depending therefrom, a separate partition assembly inserted within the channel ring below the tube support cooperating with the intermediate partition to direct the flow of fluid, a cover member, a series of peripheralbolting connections between the cover member and channel ring, a series of intermediate bolting connections between the cover member and intermediate support, a shell connected to the channel ring above the tube support, and a series of tubes within the shell and connected at their lower ends to the support with the interior of the tubes in goilnmunication with the passages formed theree ow.

4. Heat exchange apparatus comprising a tube support having an integral depending ring extending about the periphery, an integral intermediate support depending therefrom within the periphery to provide a supporting partition, a partition assembly inserted within the peripheral ring below the support and complementing the intermediate partition to direct fluid flow, a cover member, connections for securing the cover member to the ring, and intermediate connections for securing the cover member to the lowermost portion of the support.

5. Heat exchange apparatus comprising a tube support having an integral depending ring extending about the periphery, an integral intermediate support depending therefrom within the periphery to provide a supporting partition, a

' partition assembly inserted within the peripheral curing the cover member to the lowermost poran insulating'disk of asbestos or the like enclosed in a metallic cover of non-corrosive material located above the cover member and clamped between the cover member and channel ring to insulate the covermember from the hot. fluid within the chambers.

I. Heat vexchange apparatus comprising a channel ring provided with a tube support, the channel ring having a circular projecting rim and an apertured rib depending from. the tube support, a cover member, bolting connections between the periphery of the cover member and the depending rim of the channel ring, bolting connections between the intermediate rib and the contacting portion ofthe cover; the second series T ate and peripheral to be governed by the temperature oi the'cover rather than the temperature of the fluid within the chamber.

8. Heat exchange apparatus comprising a 1,997,194 cover member connected to the channel ring. and channel ring member having an integral tube support with a fluid chamber therebelow, the channel ring having an integral intermediate and apertured support depending from the tube support, accurately finishedfmeeting faces formed upon the lower portion of the channel ring and intermediate support, a cover member, bolting connections between thecover member and channel ring and the cover member and intermediate support,- the second series oi bolting connections being confined to the portion or the support beyond'the aperture, and a metal covered asbestos disk superimposed above the cover member and insulating the cover member from the heat of the fluid chamber.

L", 9. A heat exchanger including in combination a header formed by a channel member and a cover plate, an apertured supporting rib integral with said channel member, a partition rib adapted to form a compartment in the channel member, said cover plate being flat, peripheral bolts for securing said cover plate to said channel member and stud bolts extending into said supporting rib for further securing said cover plate.

CHARLES, H. LEACH.

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