Indirect heat exchanger with baffles

An indirect heat exchanger having interconnected tubes arranged to form a plurality of generally-parallel, elongated tube sections spaced from one another in a predetermined pitch pattern to form geometric void spaces between adjacent combinations of the tube sections in planes generally-perpendicular to the tube sections and separate baffle plates arranged in each of a plurality of spaced planes generally-perpendicular to the tube sections so that there is a void space on all sides of the baffle plates in each plane and arranged in different planes so that there is a void space in the planes in front of and behind each baffle. In a preferred configuration the tubes are arranged in concentric circles and the planes are spaced at a plurality of angular positions.

The present invention relates to indirect heat exchangers. More 
specifically, the present invention relates to indirect heat exchangers 
with a novel baffling arrangement. 
BACKGROUND OF THE INVENTION 
Numerous indirect heat exchanger designs have heretofore been proposed. One 
of the most effective and widely used indirect heat exchangers is a tube 
and shell type exchanger wherein one fluid is disposed in interconnected 
tubing, while the second fluid is disposed in contact with the outside of 
the tubing in a shell or other enclosure. Usually, at least one of the 
fluids is in continuous flow and, in some cases, both fluids are flowing 
in a concurrent or countercurrent direction and in yet other cases, one of 
the fluids is caused to flow noncontinuously, as by a stirrer or pump 
which simply recirculates or moves a single body of fluid, usually the 
fluid in the container or shell outside the tubing. Most such tube and 
shell type heat exchangers also include baffles which serve the dual 
purpose of supporting the tubes within the shell and to deflect, check or 
regulate the flow of fluid through the shell. 
An important objective in the design of all heat exchangers is to attain 
the most effective heat exchange possible. In this way, improved heat 
exchange can be attained with a given size heat exchanger or equivalent 
heat exchange may be obtained with a smaller heat exchanger. In most 
cases, the radical difference between the temperature of the fluid within 
the coils and the fluid outside the coils creates problems, due to the 
fact that the tubes must be permitted to move relative to one another 
because of expansion and contraction. Many baffle designs hold the tubes 
rigidly, thus preventing relative movement and ultimately causing damage 
to the exchanger if relative movement does occur. In some cases the 
differences in temperature between the two fluids are so great as to limit 
the capacity of the exchanger. For example, in reactors for chemical 
reactions, such as those for the dimerization of olefins, polymerizations 
and other reactions which are highly exothermic or endothermic, heat 
transfer is a limitation on the reactor capacity. 
It is, therefore, an object of the present invention to provide an improved 
heat exchanger which overcomes the above-mentioned and other deficiencies 
of the prior art. Another object of the present invention is to provide an 
improved heat exchanger having a novel baffle arrangement. A further 
object of the present invention is to provide an improved heat exchanger 
with a novel baffle arrangement which improves the heat exchange capacity 
of the exchanger. Another and further object of the present invention is 
to provide an improved tube and shell type heat exchanger with a novel 
baffle design which improves the circulation of fluid in the shell. Yet 
another object on the present invention is to provide an improved heat 
exchanger with a novel baffle arrangement which permits the tubes to 
expand or contract without difficulty. A still further object of the 
present invention is to provide an improved heat exchanger with a novel 
baffle arrangement which permits the conduct of highly exothermic or 
endothermic heat exchange. Another and further object of the present 
invention is to provide an improved reactor for the conduct of chemical 
reactions in which heat exchange coils are disposed within the vessel and 
a novel baffle arrangement is provided. Another object of the present 
invention is to provide a reactor having heat exchange tubes disposed in 
the vessel, a stirring means for circulating fluid in the vessel and a 
novel baffle arrangement. These and other objects of the present invention 
will be apparent from the following description. 
SUMMARY OF THE INVENTION 
The present invention relates to an indirect heat exchanger having 
interconnected tube means forming a plurality of generally parallel, 
elongated tube sections spaced from one another in a predetermined pitch 
pattern to form geometric void spaces between adjacent combinations of 
said tube sections in planes generally-perpendicular to said tube 
sections; and 
a plurality of baffle plates coincident with each of a plurality of planes 
generally-perpendicular to said tube sections and spaced along the length 
of said tube sections; 
each of said baffle plates spanning at least on of said void spaces; 
said baffle plates in each of said plurality of planes 
generally-perpendicular to said tube sections being spaced in said each of 
said plurality of planes generally perpendicular to said tube sections to 
leave a void space equal in length to each side dimension of each said 
baffle plate adjacent each side of each baffle plate; and 
said baffle plates being spaced along the length of said tube sections to 
leave at least one void space equal in transverse dimensions to a given 
baffle plate in each of said plurality of planes generally-perpendicular 
to said tube sections at both the front and rear of said given baffle 
plate. In the preferred embodiment, the tubes are formed in concentric 
circles and the planes generally-perpendicular to the tubes are at spaced 
angles with respect to each other.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The nature and advantage of the present invention will be apparent from the 
following description when read in conjunction with the drawings. 
FIG. 1 of the drawings illustrates a preferred embodiment of the present 
invention comprising a reactor for carrying out highly exothermic or 
endothermic reactions in which heat exchange is necessary in order to 
control the reaction. In accordance with FIG. 1, the reactor comprises an 
outer shell or vessel 2 provided at the upper end with one or more inlets, 
in the present case two inlets, 4 and 6, respectively. Communicating with 
the bottom of the vessel is an outlet valve 8 coupled to outlet 10. 
Disposed within vessel 2 are interconnected tubes 12 arranged in 
concentric circles. Cooling or heating fluid is introduced into the tubes 
either through inlets 14 or 16, depending upon the nature of the heat 
exchange fluid and the nature of the reaction to be conducted, while the 
other of 14 and 16 serves as a discharge for the heat exchange fluid. The 
tubes 12 are operably connected to inlet and/or outlet 14 and 16 through 
appropriate headers 18 and 20, respectively. The tubes 12 are also 
arranged concentrically about a hollow core within which is disposed an 
appropriate stirring means, such as, stirrer 22. Disposed in a plurality 
of planes generally-perpendicular to the tubes are a plurality of baffle 
plates 24, 28 and 32, respectively. 
The arrangement of the baffles is better illustrated in FIGS. 2 and 3 of 
the drawings. In accordance with FIGS. 2 and 3, it is to be noted that 
baffles 24, 28 and 32 are all located in a single plane 
generally-perpendicular to the coils and that there are a plurality of 
such planes angularly spaced from one another about the coils, 
specifically at 90.degree. angles from one another. Likewise, baffles 26 
and 30 are located in a different single plane generally perpendicular to 
the tubes and a pluraltiy of such planes having baffles 26 and 30 
coincident therewith are angularly spaced from one another about the coils 
specifically 90.degree. from one another. Consequently, the planes with 
which the baffle plates 24, 26, 28 and 32 are coincident are arranged at 
regularly spaced angular positions about the coils and specifically 
baffles 24, 28 and 32 are coincident with a plane which is 45.degree. 
removed from the plane with which baffles 26 and 30 are coincident. It 
should also be observed by viewing FIGS. 2 and 3 and particularly FIG. 2 
that baffles 24, 26, 28, 30 and 32 are disposed at different levels with 
respect to one another. By way of example, starting at the top of the 
device, baffles 24 are located on level 1, 26 on level 2, 28 on level 3, 
30 on level 4 and 32 on level 5. It is also to be observed that each of 
the baffles span at least one of the void spaces formed between adjacent 
combinations of tube sections in the planes perpendicular to the tube 
sections and specifically in the embodiment shown, each baffle spans 4 
such void spaces. In addition, each baffle plate in each of the vertical 
planes has at least one void space equal in length to each side dimension 
of the baffle plate adjacent each side of the baffle plate. Specifically, 
1 void space equal in width to the one void space of baffle plate 32 is 
adjacent the top of baffle 32 and 4 void spaces exist adjacent the side of 
baffle plate 32. By the same token, 1 void space are adjacent the bottom 
of baffle plate 28, 1 void space adjacent the top of baffle plate 28, 4 
void spaces to the right of baffle 28 and 4 void spaces to the left of 
baffle plate 28. Finally, at least one void space, equal in transverse 
dimensions to a given baffle plate coincident with a given plane 
perpendicular to the tube sections, exists between the baffle plates in 
each level of baffle plates. Specifically, between the baffle plates 24, 
28 and 32 and 2 of the planes perpendicular to the tubes there is a void 
space in the plane with which baffle plates 26 and 30 are coincident and 
between the baffle plates 26 and 30, respectively, there is a void space 
in the plane with which baffle plates 24, 28 and 32 are coincident. 
As a result of the arrangement of baffles and the reactor illustrated in 
FIGS. 1-3, a baffling effect nearly as effective as conventional baffles 
is provided, while at the same time permitting the coils to expand or 
contract without difficulty. The baffle design also allows the use of a 
smaller diameter vessel than one having conventional baffles and the 
cooling coils are more economical to manufacture than vertical tubes or 
"harp" coils. Finally, the baffle design makes it possible to carry out 
highly exothermic or endothermic reactions where heat transfer is the 
limitation on reactor capacity. The baffle arrangement also greatly aids 
the mixing device in the mixing or agitation of the reactants in the 
vessel. 
While the preferred embodiment of the present invention is illustrated in 
FIGS. 1-3, it is to be noted that various other arrangement of indirect, 
tube and shell type heat exchangers will be apparent to one skilled in the 
art and many modifications are possible without departing from the basic 
concepts of the present invention. 
FIGS. 4, 5 and 6 illustrate another such embodiment of the present 
invention. In FIGS. 4, 5 and 6 the heat exchanger is formed by 
interconnected tubes 34 formed in generally parallel tube sections, in 
this case, a square bundle arrangement of straight tube sections. The 
tubes would be interconnected by a suitable header at the upper entry 
tubes (not shown) and another suitable header at the lower exit of the 
tubes (not shown). The tube bundle would be surrounded by an appropriate 
outer shell (not shown). The baffle plates comprise baffle plates 36, 38, 
40, 42, 44 and 46 located on levels 1, 2, 3, 4, 5 and 6, respectively, 
reading from top to bottom. The baffle plates are also located coincident 
with planes perpendicular to the tubes. Specifically, the baffle plates 
38, 42 and 46 are coincident with one plane and baffle plates 36, 40 and 
44 with the next adjacent plane. Again it is to be observed, by reference 
specifically to FIG. 6, that the baffle plates span one of the void spaces 
between adjacent combinations of tube sections (4 tube sections) in a 
plane perpendicular to the tube sections. The baffle plates in each plane 
are also arranged so as to leave one void space on each side thereof, 
which is equal in length to one side dimension of the baffle plate. Also 
the baffle plates are spaced along the length of the tube sections to 
leave one void space equal in transverse dimensions to a given baffle 
plate at both the front and the rear of the given baffle plate. 
Specifically, the baffle plates 38, 42 and 46 leave a void space in the 
plane coincident with baffle plates 36, 40 and 44 and likewise, the baffle 
plates 36, 40 and 44 leave a void space therebetween in the plane with 
which baffle plates 38, 42 and 46 coincide. 
Obviously, the heat exchanger of the present invention may take any one of 
a wide variety of forms being either vertically disposed or horizontally 
disposed, having a wide variety of shell configurations and having either 
or both of the tubes in the shell arranged with inlets and outlets so that 
one or both of the fluids in the tubes or the shell, respectively, may be 
circulated therethrough. The tubes may also be arranged in any one of a 
wide variety of configurations or any desired pitch, such as an 
equilateral triangle pitch, a square pitch, a hexagonal pitch or any other 
desired arrangement. A square pitch is illustrated and is usually 
preferred. The heat exchangers are obviously adaptable for use in 
reactors, such as the stirred reactor illustrated in FIGS. 1-3 of 
conventional indirect heat exchangers which could utilize an arrangement 
such as that of FIGS. 4, 5 and 6. 
While specific structures and arrangements have been illustrated in the 
present application, it is to be understood that these are by way of 
illustration only and modifications, variations and equilvalents thereof 
will be apparent to one skilled in the art.