US1940338A - Oil distillate cooler or condenser - Google Patents

Description

Dec. 19, 1933. J. s. WALLIS 1,940,338

OIL DISTILLATE COOLER OR CONDENSER Filed on. 25. 1950 2 Sheets-Sheet 1 A; ATTORNEY Dec. 19, 1933; .1. s. WALLIS OIL DISTILLATE COOLER OR CONDENSER Fild Oct. 25, 1930 2 Sheets-Sheet 2 ii 13 0 u! m. -M W VIlLWI'lr/ 7. O

dag I/g/jNTOR 46,; ATT-OR EY the tubes withcastings.

Patented Dec. 19, 1933 UNITED STATES PATENT OFFICE a 1,940,338 OIL DISTILLATE COOLER 0R. CONDENSER,

v John Samuel Wallis, New York, N. Y. I Application October 25, 1930. Serial No. 491,183

'1 Claims. 01, 257-196) My invention relates to coolers or condensers for cooling oil,that is hydrocarbon fluid, in oil distillation processes and the like. a h 7 Oil products leaving a fractionating tower or 6 other oil treatment apparatus, pass through condensers or coolers or both. Since condensers are coolers, such devices'wil1 in general herein be termed coolers. a,

So far as I am' aware, previously known comll) mercial coolers consist of pipe coils submerged in a water tank-There. are two objections to this known type ofcooler; first, as respects space required; and, second, as respects heat transfer. The coils usually consist of vertically disposed ,1 rows of horizontal tube portions connected alternately at the ends by bends. The horizontal portions of these tubes are arranged about a foot apart. In acooler of this'known type, furthermore, the inside surface, which is contacted-by oil, isless area than the outside surface, which is contacted by water. The specific heat of water is approximatelytwice that of oil, and the rate of heat transferflbetween metal and water isgreater by several times thanthe rate of heat transfer betweenmetm and'oil. "The heat transfer between the oil and the'metal wall is consequently the limiting factor. V a

I propose to overcome theabove disadvantages and, to provide an improved cooler by" replacing These castings have, preferably, smooth outside vertical walls. Inter- Dally the castings contain ribs which serve, two purposes. The ribs are arranged to form a pluralityof, horizontal passages alternately conn'ected 38 at opposite ends'of the castings; Theflrlbs further appreciably increase the inside or oil contact surfaces relative to the external or water contact surfaces, Variousfo'rms ofribs may beused, but each casting is preferably so designed that the 0 oil contact surface and thewater contact surface are ininve'rse proportion, or at least substantially inverse proportion, to the specific heat of the respective fluidsand preferably in inverse proportions to the rates ofheat transfer between the respective fluids and the casting. Since the ribs are notqulte as eflicient as the side walls for the transmission of heat, I preferably provide an excess of internal surface above the ratio set forth. The vertical walls of thecsides ofthe castings determine passages for the water betweenthem. Since a greater length of path of flow, by several times, can be included in a given vertical height of casting than in a pipe type cooler, a smaller number of vertically disposed members can be employed, and consequently the size of the water ing has side walls 16 which are parallel and ver- .tically disposed, a top wall 17, a bottom wall 18 webs 24 extend between the sidewalls 16 and are of less'length than the internal lengthof tank can be materially reduced; The reduction of the water tank provides greater velocity in the water tank between the'castings and in contact with the side walls thereof, which increase in velocity is an aid to heattransfer and helps to so improve the efliciency. I find that with the present invention the size of water tank for a given capacity can becut substantially in half. Furthermore, since a smaller member of vertically disposed memberscan be employed, the oil velocity will be increased as compared with the previously known coolers and thus the heat transfer from the oil is'also improved due to its velocity.

Myinvention is'illustrated on the accompanying drawings, forming a part of thisspecification and on whichd i Fig. 1 is an elevational cross-sectional view of one'embodiment of the invention, taken on the line 1--l of Fig. 2;

Fig. 2 is atransverse cross section taken on the line 2-2 of Fig. 1; and V 1 Figs. 3 through 6'show difierent kinds of ribs for use in the casting of Figs. 1 and 2.

' My improved cooler includes a water tank 10 having an inlet 11 and an outlet 12. Within the watertank is a plurality of vertically disposed 'oil contacting groupsof cooling sections 14. Each group, in the embodiment shown, includes two castings disposed one above the other. Each castyes andyend walls 19. The end walls 19 are parallel V and vertically disposed. The top and bottom walls 17 and 18 are parallel and horizontally disposed.

At the top of each casting is an inlet 20 and at the ,90

bottom of each casting is an outlet 21, Spacing members 22m cast integral with the castings.

Each casting is an integral casting, thus eliminating substantially all connections. Horizontal the casting. Alternate webs extend from opposite end walls to substantially the other end wall respectively. Each web terminates short of one end wall by an amount substantially equal to the distancebetween the webs. The webs thus form parallel horizontal passages which are connected in series alternately at opposite ends of the castings.

In the embodiment shown, four groups of castings of two castings each, are arranged vertically in the water tank 10. The upper connections of the upper castings are connected to a common inlet header 26, to which'the oil is supplied. The

lower ends of the lower casting are connected to 7110 a common outlet header 27, through which the oil is conducted to storage or other place depending upon the process. I-beams 28 and saddles 29 or other supporting means may be provided to support the castings. The oil flows in parallel downwardly through the castings, the castings being connected in series as shown in the drawings. It will be seen that the external water-cooled surface of each casting is less than the internal oil contact surface due to the provision of the webs 24. As shown in Fig. 2, the webs 24 are slightly wider than the vertical distance between the webs. The internal surface has an area which is somewhat greater than twice the outside sur-' face. This, as above stated, is done to compensate for the difference in specific heat and rate of heat transfer between oil and water. Tests have shown that webs do not give 100% heat transmitting efliciency, but webs arranged as shown in the drawing should give approximately efficiency for the flows encountered in normal use for oil cooling. This factor should therefore be taken into account in increasing the internal surface above that which corresponds to the inverse ratio of specific heatsand heat transfer rates of the respective fluids. V

Holes and plugs indicated at 30 are provided opposite each web at the point where it is spaced from an end wall. Each hole affords access to two horizontal passages, thus facilitating cleaning with a minimum number of plugs. The plug holes are useful in casting the section.

By casting the sections integral, I provide a minimum of bolted joints, there being bolted joints only where the castings are connected to the manifolds or headers and-where the castings are connected to each other in such instances asa plurality of castings being used in each section. The use of a casting permits the horizontal oil passages to be immediately adjacent each other and thus provide many more passages per unit height than with the old type of oil cooler. It is impossible to have the horizontal portions of a pipe cooler adjacent to eachother on account of .the end bends or loops. My cooler ,provides this advantage, while at the same time givingv the advantage of a proper heat transfer in accordance with the characteristics of the liquids. Since there are so many more horizontal passages, the watertank can be reduced relativeto the size required for a pipe cooler, and consequently the velocity of the water flowing upwardly and alongside the castings is greater than the rate of new of water in a pipe cooler. Dead spaces between horizontal pipe portions are eliminated, the castings acting as baflies to give positive flow.

Heat transfer increases with increased velocity, and therefore my cooler is improved in efficiency due to the faster flow of water caused by the de crease of tank. size, in turn caused by the use of castings.

The webs may be of various forms. Fig. 3 shows horizontal webs wherein the webs are substantially as wide as the passages between the webs. In this arrangement the internal surface is approximately twice the external surface. Fig. 4 shows webs of angular form, the internal surface extending obliquely to the side walls. This gives a greater amount of internal surface for a given width of casting.

Fig. 5 shows different forms of webs. To in crease the internal surface, I provide fins 16. It will beobvious that these fins may be employed in the other forms of construction shown. In cases where internal parallel surfaces are used,

I prefer to have the bottom surface smooth and the other surfaces of irregular form. The reason for this is to prevent deposits on the bottom surface.

Fig. 6 shows still another form of web in which the web is thinner at the center than at the side walls.

It will be understood that the invention is not limited to the precise structure described and illustrated. For example, the casting need not necessarily be arranged vertically as shown.

What I claim is:

1. An integral casting for an oil cooler comprising parallel side walls, parallel end walls, parallel top and bottom walls, and internal webs parallel to the top and bottom walls and extending alternately from opposite end walls to substantially the other end wall respectively and providing a plurality of parallel passages for flow of oil connected in series, said passages having an internal surface of greater area than external surface and said webs being thicker adjacent the side walls than at more central points.

2. A water cooled oil cooler comprisinga water tank having, an inlet and an outlet, a plu-, rality of V parallel-vertically disposed. oil-conducting cooling sections in said water tank, each section consisting of a unitary casting having parallel side walls'and internal webs, said webs extending alternately from opposite end walls of the casting to substantially the other end wall respectively and providing a pluralityof parallel horizontal passages for flow of oil connected in series, said webs providing aninternal oil con- .tact surface greater than the external water contact surface, said webs being thicker adjacent the side walls than at more central, points, and means comprising inlet and outlet headers for connecting the sections in paralleL' 3. A water cooled oil cooler comprising'ja water tank having an inlet and an outlet, aplurality of parallel vertically disposed oil-conducting cooling sections in said water tank, each section consisting of a unitary casting having parallel side wallsand internal webs, said webs extending alternately from opposite end walls of the casting to substantially the other end wall respectively and providing a plurality of parallel horizontal passages for flow of oil connected in series, said webs-providing an internal oil contact surface greater than the external Water contact surface, said webs having surfaces extending obliquely to the side walls, andmeans comprising inlet and'outlet headers for connecting the sections in parallel.

4. A water cooled oil cooler comprising a water tank having an inlet and an outlet, a plurality of parallel vertically disposed oil conducting cooling sections in'said water tank, each section consisting of a unitary casting having parallel side walls and internal webs, said websextending alternately from opposite end, walls of the casting to substantially the other end wall reparallel to the top and bottom walls and extending alternately from opposite end walls to substantially the other end wall respectively and providing a plurality of parallel passages for flow of oil connected in series, said passages having an internal surface of greater area than external surface and said webs having surfaces extend- 7. An oil cooler comprising in combination a casing adapted to receive a cooling medium, a plurality of castings disposed within said casing adapted to be surrounded by said cooling medium, said castings having internally extended surfaces having a greater area than the external surfaces thereof, a part of said internally extended surfaces arranged to constrain the flow of the liquid within the castings in predetermined paths, another part of said internally extended surfaces adapted to provide an increased heat exchange surface, said last named surfaces being disposed to avoid resistance to the flow of a liquid thereover, inlet openings for said castings, outlet openings for said castings and respective manifolds communicating with said inlet and outlet. openings.

' JOHN SAMUEL WALLIS.

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