Title of Invention

HEAT EXCHANGER

Abstract

A heat exchanger has an outer pressure jacket (1), which is provided with an entry connection (5) for the supply of and an exit connection (7) for the removal of a first heat exchange medium, the jacket surrounding U-shaped, bent pipes (2) through which a second heat exchange medium flows. The pipes are mounted in a pipe supporting floor (3) that is connected with the pressure jacket (1). The U-shaped pipes (2) are surrounded by a guide jacket (13) which is inwardly radially spaced from the inside wall of the pressure jacket (1) and defines an intermediate annular space (14) therewith. Inner and outer legs of the U-shaped pipes (2) are respectively positioned on one of two concentrical partial circles. The inner pipe legs surround a central pipe (11) which is oriented along the longitudinal axis of the heat exchanger, is connected with the entry connection, is open towards the interior of the heat exchanger, and extends from one end of the heat exchanger to the vicinity of the pipe supporting floor (3) which is located at the other end of the heat exchanger. A separator jacket (12) is positioned between the inner and outer legs of the U-shaped pipes (2) and is connected to the pipe supporting floor (3). The guide jacket (13) is sealingly connected at one end with the central pipe (11) and at its open end extends close to the pipe supporting floor (3). The exit connection (7) which originates from the annular space (14) between the guide jacket (13) and the pressure jacket (1) is positioned at that end of the heat exchanger which is remote from the open end of the guide jacket (13). The central pipe (11) is provided at an inflow end with a valve chamber 16 including a valve arrangement for controlling the flow of the heat exchange medium through the central pipe for adjustment of the temperature of the heat exchange medium flowing in the jacket. (Fig. 1)

Full Text

HEAT EXCHANGER The invention relates to heat exchangers for the transfer of heat energy between first and second fluid heat transfer media, in particular, heat exchangers having an outer pressure jacket, U-shaped heat exchange medium carrying pipes, and an intermediate guide jacket. A heat exchanger of this general type is known from DE-PS 20 33 128. In this known heat exchanger the guide jacket is open at both ends and is provided in the middle with a feed connection for the first fluid medium flowing through the jacket. The first medium which is the medium to be cooled is distributed within the guide jacket to both sides to flow partly parallel to the second fluid medium in the heat exchange pipes and partly in counter flow thereto. Thereafter, the first medium in the jacket enters into the annular space between the guide jacket and the outer pressure jacket from which it is subsequently drained. In this manner, it is achieved that the pressure jacket does not come into contact with medium of high entry temperature. In some applications, it is desired to control the temperature of the medium to be cooled and flowing inside the jacket. To achieve this goal, a bypass arrangement is known (DE-PS 28 46 455) which consists of a central pipe that is positioned parallel to the longitudinal axis of the heat exchanger. This central pipe directly connects a hot gas entry chamber with a cooled hot gas exit chamber and at one end houses a closing or regulating member. This bypass arrangement is only usable in straight pipe heat exchangers wherein the heat exchange pipes are held in two pipe supporting floors which respectively delimit the gas entry chamber and the gas exit chamber. It is an object of the invention to provide a heat exchanger with U-shaped pipes, wherein the final temperature of the medium in the jacket can be controlled and the pressure jacket is protected from an excessive temperature load. Accordingly, the invention provides a heat exchanger for transferring heat between first and second heat exchange media, including an outer pressure jacket which is provided with an entry connection for the supply of and an exit connection for the removal of the first heat exchange medium. U-shaped pipes are positioned within the pressure jacket which are affixed in a pipe supporting floor that is connected with the pressure jacket. A guide jacket surrounds the U-shaped pipes and is radially spaced apart from the inside wall of the pressure jacket and defines an intermediate annular space therewith. Inner and outer legs of the U-shaped pipes are respectively positioned on one of two concentrical partial circles, the inner pipe legs surrounding a central pipe which is oriented along the longitudinal axis of the heat exchanger. The central pipe is connected with the entry connection, is open towards the interior of the heat exchanger, and extends from one end of the heat exchanger close to the pipe supporting floor which is located at the other end of the heat exchanger, a separating jacket being positioned between the inner and outer legs of the U-shaped pipes and being connected to the pipe supporting floor. The guide jacket is sealingly connected at one end with the central pipe and with its open end extends close to the pipe supporting floor. The exit connection which originates from the annular space between the guide jacket and the pressure jacket is positioned at that end of the heat exchanger which is remote from the open end of the guide jacket. The positioning of the U-shaped pipes and the multiple redirecting of the heat exchange medium flowing in the jacket within the heat exchanger by way of the guide end separating jackets makes it possible to provide the central pipe with a shut-off and control member and to thereby provide a heat exchanger with U-shaped pipes having a bypass arrangement. At the same time, the medium in the jacket is guided such that it only contacts the pressure jacket after it has been cooled to some degree. Several embodiments of the invention are illustrated in the drawing and described in the following. It shows: Fig. 1 a longitudinal section through a preferred heat exchanger in accordance with the invention; Fig. 2 a longitudinal section through a heat exchanger according to another preferred embodiment; and Fig. 3 a detail Z of Fig. 1 or 2. The preferred heat exchangers illustrated in the drawings are preferably used for the cooling of hot gases from an ammonia or methanol producing plant or from a coal degassing plant whereby steam is used as the cooling medium and superheated for cooling of the hot gases. In the preferred embodiment shown in Fig. 1, the heat exchanger includes a pressure jacket 1 which encloses a bundle of U-shaped, bent pipes 2. The pipes 2 are fitted into a pipe supporting floor 3, which is connected with the pressure jacket 1. On the side of the pipe supporting floor 3 which is remote from the pipes 2 is provided an entry chamber 4 with an entry connection 5 for the feeding of a first heat exchange medium, for example, steam. An exit chamber 6 is positioned within the entry chamber 4, which is connected with the pipe supporting floor 3 and sealed from the entry chamber 4. The exit chamber 6 is provided with an exit connection 7 which protrudes from the entry chamber 4. The U-shaped pipes 2 are oriented such that the inflow ends thereof are located on a partial circle and the outflow ends thereof are located on another partial circle. The inflow ends of the pipes 2 open into the entry chamber 4 and the outflow ends open into the exit chamber 6. This results in a flow direction of the first heat exchange medium in the pipes as indicated by the arrows. As illustrated in Fig. 1, the exit chamber 6 is preferably of circular cross-section and centrally positioned, which means concentrical with a longitudinal axis of the heat exchanger. In another preferred embodiment, as shown in Fig. 2, the flow direction of the first heat exchange medium in the pipes can also be opposite from that in the embodiment of Fig. 1. In that case, the exit chamber 6 is of annular cross-section and the entry chamber 4 unchanged so that the outflow ends of the pipes 2 which are located on the larger partial circle now open into the exit chamber 6. On the side of the pipe supporting floor 3 which is oriented towards the pipes, the pressure jacket 1 is provided with a feed connection 8 for the supply of a second heat exchange medium, for example, a hot gas from an ammonia or methanol producing plant or from a coal degassing plant. On the same end of the heat exchanger, an outlet connection 9 is provided for removal of the second heat exchange medium. The feed connection 8 is connected through a supply channel 10 with a central pipe 11 which is open at one end, extends along the longitudinal axis of the heat exchanger, and is surrounded by the U-shaped pipes 2. The central pipe 11 ends in the vicinity of the pipe supporting floor 3. A cylindrical separating jacket 12 is positioned between the inner and outer legs of the U-shaped pipes. This separating jacket 12 is connected with the pipe supporting floor 3 and extends up to the return bends of the U-shaped pipes 2. A guide jacket 13 surrounds the external legs of the pipes 2 which jacket has an open and a closed end and is radially spaced apart from the pressure jacket 1, defining an intermediate annular space 14 therewith. The guide jacket 13 at its closed end is tightly connected at one end with the central pipe 11 and extends with its open end close to the pipe supporting floor 3. Metal deflector sheets 15 are positioned in the space enclosed by the central pipe 11 and the guide jacket 13 and perpendicular to the pipes 2. The second heat exchange medium entering the heat exchanger through the feed connection 8 flows through the central pipe 11, is redirected in the vicinity of the pipe supporting floor 3, subsequently flows through the intermediate space between the central pipe 11 and the separating jacket 12, is then redirected at the closed end of the guide jacket 13, flows thereafter through the intermediate space between the guide jacket 13 and the separating jacket 12, exits at the open end of the guide jacket 13 and enters into the annular space 14 between the guide jacket 13 and the pressure jacket 1, from where it is removed by way of the outlet connection 9. The resulting flow of the second heat exchange medium flowing through the jacket is indicated by the arrows in Figure 1. The medium in the jacket thereby flows in counter-current to the first heat exchange medium flowing through the pipes in the embodiment of Fig. 1 and in parallel thereto in the embodiment of Fig. 2. In the illustrated embodiments, the medium in the jacket is cooled by heat exchange with the cooler medium in the pipes 2 and impinges on the pressure jacket 1 only in the cooled condition. In this way, additional protective insulation on the inside of the pressure jacket 1 is obviated. However, the heat exchanger of the present invention is not limited to this preferred mode of operation. It is also possible to direct the cooler heat exchange medium through the jacket and the hotter heat exchange medium through the U-shaped pipes. A cylindrical valve chamber 16 is integrated into the central pipe 11 at the inflow end thereof and the supply channel 10 radially opens there into. The valve chamber 16 is provided with first and second openings 17, 18 respectively connected with the central pipe 11 and the interior of the pressure jacket 1. A valve plate 19 is axially movably positioned in the valve chamber 16, which plate is movable between respective end positions by way of an operating rod 20 which protrudes from the pressure jacket 1. In one end position, the open position, the valve plate 19 closes the opening 17 to the central pipe 11 and in the other end position, the closed position, it closes the opening 18 to the interior of the pressure jacket 1. There between any intermediate position is possible. In the open position (solid lines in Fig. 3) the heat exchange medium flowing into the valve chamber 16 through the entry connection 8 is removed directly and without cooling through second opening 18 and outlet connection 9 and without contact with the pipes 2. In the closed position (broken lines in Fig. 3) the medium flows into the central pipe 11 through first opening 17 and is guided along the pipes 2 with repeated redirectioning before removal thereof through the annular space 14 and the outlet connection 9. This case is also shown in Figs. 1 and 2. In this way, the medium flow through the openings in the chamber 16 can be varied between zero and one hundred percent by way of a single adjustment movement of the rod 20 connected to the valve plate 19 - i.e. through movement of a single adjustment member. Any desired exit temperature of the medium in the jacket or the pipes can be adjusted this way. Changes and modifications in the specifically described embodiments can be carried out without departing from the scope of the invention which is intended to be limited only by the scope of the appended claims. Claims 1. Heat exchanger for transferring heat energy between first and second fluid heat exchange media, comprising an outer pressure jacket, which is provided with an entry connection for the supply of and an exit connection for the removal of the first heat exchange medium, U-shaped pipes positioned within the pressure jacket which are affixed in a pipe supporting floor that is connected with the pressure jacket, a guide jacket which surrounds the U-shaped pipes and is radially spaced apart from the inside wall of the pressure jacket and defines an intermediate annular space therewith, inner and outer legs of the U-shaped pipes being respectively positioned on one of two concentrical partial circles, the inner pipe legs surrounding a central pipe which is oriented along the longitudinal axis of the heat exchanger, is connected with the entry connection, is open towards the interior of the heat exchanger, and extends from one end of the heat exchanger close to the pipe supporting floor which is located at the other end of the heat exchanger, a separating jacket being positioned between the inner and outer legs of the U-shaped pipes and being connected to the pipe supporting floor, wherein the guide jacket is sealingly connected at one end with the central pipe and with its open end extending close to the pipe supporting floor, and the exit connection which originates from the annular space between the guide jacket and the pressure jacket is positioned at that end of the heat exchanger which is remote from the open end of the guide jacket. 2. Heat exchanger according to claim 1, wherein a closing member is provided at an input end of the central pipe. 3. Heat exchanger according to claim 2, wherein a valve chamber is provided at the input end of the central pipe which is provided with first and second openings, the first opening communicating with the central pipe and the second opening communicating with the interior of the pressure jacket, a valve plate being provided in the valve chamber which plate is movable in the valve chamber to respectively close one of the openings. 4. Heat exchanger according to one of claims 1 to 3, wherein the pipe supporting floor on a side remote from the pipes delimits an entry chamber in which an exit chamber is positioned, the entry chamber communicating with the entry ends of the pipes, and the exit chamber being connected with the pipe supporting floor and being provided with an exit connection, the exit ends of all pipes opening into the exit chamber. 5. Heat exchanger according to claim 4, wherein the exit chamber is of circular cross-section and is centrally positioned within the entry chamber 6. Heat exchanger according to claim 4, wherein the exit chamber is of circular cross-section. 7. Heat exchanger for transferring heat energy between first and second fluid heat exchange media substantially as herein described with reference to the accompanying drawings.

Documents:

mas-1998-414-abstract.pdf

mas-1998-414-assignment.pdf

mas-1998-414-claims duplicate.pdf

mas-1998-414-claims original.pdf

mas-1998-414-correspondance others.pdf

mas-1998-414-correspondance po.pdf

mas-1998-414-description complete duplicate.pdf

mas-1998-414-description complete original.pdf

mas-1998-414-form 1.pdf

mas-1998-414-form 26.pdf

mas-1998-414-form 3.pdf

mas-1998-414-other document.pdf