Heat exchanger

Abstract

A heat exchanger includes a plurality of heat transfer tubes (3) and a centrally arranged bypass tube (4), which are held each between a tube plate (5) of a gas inlet chamber (7) and a tube plate (6) of a gas outlet chamber (8) that are connected to a cylindrical jacket. A coolant (11) is introduced into the jacket space (9) enclosing the tubes (3, 4). A control device (16), includes a throttle valve (18) and a drive (19), sets a gas outlet temperature range of the heat exchanger (1). A discharge rate and a discharged quantity of an uncooled process gas stream (14) from the bypass tube is controlled by the throttle valve, at an outlet end (17) of the bypass tube and is adjustable via the control device. The throttle valve is formed of a material resistant to high-temperature corrosion in a temperature range sensitive for high-temperature corrosion.

Claims

1. A heat exchanger comprising: a cylindrical jacket; a plurality of heat transfer tubes; a centrally arranged bypass tube; a gas inlet chamber tube plate cooperating with the cylindrical jacket to form a gas inlet chamber; a gas outlet chamber tube plate cooperating with the cylindrical jacket to form a gas outlet chamber, the bypass tube and the heat transfer tubes being held between the gas inlet chamber tube plate and the gas outlet chamber tube plate, wherein the gas inlet chamber tube plate and the gas outlet chamber tube plate are connected to the cylindrical jacket to form a jacket space therewithin, whereby the heat transfer tubes and the bypass tube are enclosed and a coolant can be introduced into the jacket space; at least one inlet pipe connected to the cylindrical jacket for introducing a coolant into the jacket space to a jacket side of the heat transfer tubes; at least one outlet pipe connected to the cylindrical jacket for draining off a water/vapor mixture from the jacket space, which is produced by indirect heat transfer via the jacket side of the heat transfer tubes; an inlet pipe arranged laterally or axially at the gas inlet chamber in front of the tube plate in a gas flow direction for introducing a hot process gas stream into the heat transfer tubes and into the bypass tube on a gas inlet side of inlet chamber tube plate; a discharge pipe arranged laterally or axially at the gas outlet chamber behind the tube plate in the gas flow direction for draining off a mixture of the cooled process gas streams from the heat transfer tubes and from the uncooled process gas stream from the bypass tube on the gas outlet side of the outlet chamber tube plate; and a control device comprising a drive and a throttle valve connected to the drive for setting a gas outlet temperature of the heat exchanger to a certain temperature range by mixing the cooled process gas streams from the heat transfer tubes with the uncooled process gas stream from the bypass tube, the throttle valve being arranged at an outlet end of the bypass tube, the throttle valve being arranged in a valve housing, the drive being arranged outside the heat exchanger, wherein a discharge rate and a discharged quantity of the uncooled process gas stream from the bypass tube is controlled by the throttle valve and is adjustable via the drive of the control device, wherein the throttle valve is manufactured from a material resistant to high-temperature corrosion in a temperature range sensitive to high-temperature corrosion and wherein the valve housing is manufactured from a material not necessarily fully resistant to high temperature corrosion, but operated at a temperature outside of the range of high temperature corrosion and wherein the valve housing is protected by an insulation against high temperatures, the temperature range being around 500° C. to about 850° C., the material resistant to high-temperature corrosion comprising a ceramic material.

2. A heat exchanger in accordance with claim 1, wherein the control device further comprises double joints adjustably connecting the throttle valve of the control device to the drive.

3. A heat exchanger in accordance with claim 2, wherein the control device further comprises a shaft, the shaft and the double joints connecting the throttle valve of the control device to the drive.

4. A heat exchanger in accordance with claim 1, wherein the control device further comprises double joints and a shaft and the shaft and the double joints connect the throttle valve of the control device to the drive.

5. A heat exchanger in accordance with claim 2, wherein: heat insulation is applied on valve housing inner walls of the valve housing and a bearing at two wall sides is formed in the heat insulation applied on the inner walls; a bearing is provided in a wall of the gas outlet chamber; the throttle valve has an integrated shaft supported by the bearing at two wall sides and with a shaft end; a shaft is arranged in the bearing in the wall of the gas outlet chamber; and the double joints are connect to the drive via the shaft end and the shaft for compensating differences in expansion between the respective bearing of the shaft end of the throttle valve in the valve housing and the bearing of the shaft arranged in the wall of the gas outlet chamber.

6. A heat exchanger in accordance with claim 3, wherein: the heat insulation is applied on valve housing inner walls of the valve housing and valve bearings at two wall sides are formed in the heat insulation applied on the inner walls; the throttle valve has a shaft arrangement with a shaft end portion in one of the valve bearings and another shaft end portion in another of the valve bearings; a chamber wall bearing is provided in a wall of the gas outlet chamber; the shaft is arranged in the chamber wall; and the shaft connects the double joints to the drive and the shaft end portion connects the double joints to the throttle valve whereby the double joints compensate for thermal expansion differences between one or more of the valve bearings and the chamber wall bearing.

7. A heat exchanger in accordance with claim 1, wherein the throttle valve comprises a valve body arranged rotatably in the valve housing and acting at right angles to the gas flow direction, wherein the valve body is rotatable relative to the valve housing.

8. A heat exchanger in accordance with claim 5, wherein the throttle valve comprises a valve body arranged rotatably in the valve housing and acting at right angles to the gas flow direction, wherein the valve body is rotatable relative to the valve housing about an axis perpendicular to the gas flow direction.

9. A heat exchanger in accordance with claim 6, wherein the throttle valve comprises a valve body arranged rotatably in the valve housing and acting at right angles to the gas flow direction, wherein actuation of the drive rotates the throttle valve, relative to the valve housing, to adjust a flow rate of the uncooled process gas stream exiting the bypass tube.

10. A heat exchanger in accordance with claim 1, wherein the valve housing is configured as an extension of the bypass tube, the valve housing having: essentially a same diameter as the bypass tube; or an expanded diameter with a conical attachment as a transition from an outlet end of the bypass tube to the expanded diameter.

11. A heat exchanger in accordance with claim 1, wherein the ceramic defines a metal-dusting-resistant or high-temperature-resistant material.

12. A heat exchanger comprising: a cylindrical jacket; a plurality of heat transfer tubes; a centrally arranged bypass tube; a gas inlet chamber tube plate cooperating with the cylindrical jacket to form a gas inlet chamber; a gas outlet chamber tube plate cooperating with the cylindrical jacket to form a gas outlet chamber, the bypass tube and the heat transfer tubes being held between the gas inlet chamber tube plate and the gas outlet chamber tube plate, wherein the gas inlet chamber tube plate and the gas outlet chamber tube plate are connected to the cylindrical jacket to form a jacket space, whereby the heat transfer tubes and the bypass tube are enclosed and a coolant can be introduced into the a jacket space; at least one inlet pipe connected to the cylindrical jacket for introducing a coolant into the jacket space to a jacket side of the heat transfer tubes; at least one outlet pipe connected to the cylindrical jacket for draining off a water/vapor mixture from the jacket space, which is produced by indirect heat transfer via the jacket side of the heat transfer tubes; an inlet pipe connected to the gas inlet chamber for introducing a hot process gas stream into the heat transfer tubes and into the bypass tube on a gas inlet side of inlet chamber tube plate; a discharge pipe connected to the gas outlet chamber for removing a mixture of the cooled process gas streams from the heat transfer tubes and from the uncooled process gas stream from the bypass tube on the gas outlet side of the outlet chamber tube plate; and a control device comprising a drive and a throttle valve connected to the drive for setting a gas outlet temperature of the heat exchanger to a certain temperature range by mixing the cooled process gas streams from the heat transfer tubes with the uncooled process gas stream from the bypass tube, the throttle valve being arranged at the outlet end of the bypass tube, the throttle valve being arranged in a valve housing, the drive being arranged outside the heat exchanger, wherein a discharge rate and a discharged quantity of the uncooled process gas stream from the bypass tube is controlled by the throttle valve and is adjustable via the drive of the control device, wherein the throttle valve comprises a valve body formed of a high-temperature corrosion range corrosion resistant material, the temperature range being around 500° C. to about 850° C., the high-temperature corrosion range corrosion resistant material comprising a ceramic material.

13. A heat exchanger in accordance with claim 12, wherein the control device further comprises double joints and a shaft and the shaft and the double joints connect the throttle valve of the control device to the drive.

14. A heat exchanger in accordance with claim 13, wherein: heat insulation is applied on valve housing inner walls and valve bearings at two wall sides are formed in the heat insulation applied on the inner walls; the throttle valve has a shaft arrangement with a shaft end portion in one of the valve bearings and another shaft end portion in another of the valve bearings; a chamber wall bearing is provided in a wall of the gas outlet chamber; the shaft is arranged in the chamber wall; and the shaft connects the double joints to the drive and the shaft end portion connects the double joints to the throttle valve whereby the double joints compensate for thermal expansion differences between one or more of the valve bearings and the chamber wall bearing.

15. A heat exchanger in accordance with claim 14, wherein the valve body is arranged rotatably in the valve housing and acts at right angles to the gas flow direction.

16. A heat exchanger in accordance with claim 15, wherein the valve housing is configured as an extension of the bypass tube, the valve housing having: essentially a same diameter as the bypass tube; or an expanded diameter with a conical attachment as a transition from an outlet end of the bypass tube to the expanded diameter.

17. A heat exchanger in accordance with claim 12, wherein the corrosion resistance of the material includes metal-dusting-resistance.

18. A heat exchanger in accordance with claim 12, wherein the throttle valve comprises a valve body, the valve body being rotatable relative to the valve housing.

19. A heat exchanger in accordance with claim 12, wherein actuation of the drive rotates the throttle valve to adjust a flow rate of the uncooled process gas stream exiting the bypass tube.

20. A heat exchanger comprising: a cylindrical jacket; a plurality of heat transfer tubes; a centrally arranged bypass tube; a gas inlet chamber tube plate cooperating with the cylindrical jacket to form a gas inlet chamber; a gas outlet chamber tube plate cooperating with the cylindrical jacket to form a gas outlet chamber, the bypass tube and the heat transfer tubes being held between the gas inlet chamber tube plate and the gas outlet chamber tube plate, wherein the gas inlet chamber tube plate and the gas outlet chamber tube plate are connected to the cylindrical jacket to form a jacket space, whereby the heat transfer tubes and the bypass tube are enclosed and a coolant can be introduced into the a jacket space; at least one inlet pipe connected to the cylindrical jacket for introducing a coolant into the jacket space to a jacket side of the heat transfer tubes; at least one outlet pipe connected to the cylindrical jacket for draining off a water/vapor mixture from the jacket space, which is produced by indirect heat transfer via the jacket side of the heat transfer tubes; an inlet pipe connected to the gas inlet chamber for introducing a hot process gas stream into the heat transfer tubes and into the bypass tube on a gas inlet side of inlet chamber tube plate; a discharge pipe connected to the gas outlet chamber for removing a mixture of the cooled process gas streams from the heat transfer tubes and from the uncooled process gas stream from the bypass tube on the gas outlet side of the outlet chamber tube plate; and a control device comprising a drive and a throttle valve connected to the drive for setting a gas outlet temperature of the heat exchanger to a certain temperature range by mixing the cooled process gas streams from the heat transfer tubes with the uncooled process gas stream from the bypass tube, the throttle valve being arranged at the outlet end of the bypass tube, the throttle valve being arranged in a valve housing, the drive being arranged outside the heat exchanger, wherein a discharge rate and a discharged quantity of the uncooled process gas stream from the bypass tube is controlled by the throttle valve and is adjustable via the drive of the control device, wherein the throttle valve comprises a valve body, the valve body comprising a ceramic material, the ceramic material being corrosion resistant in a temperature range of 500° C. to about 850° C.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings:

(2) FIG. 1 is a longitudinal sectional view through a heat exchanger, on a reduced scale, according to the present invention; and

(3) FIG. 2 is a detail X of FIG. 1 as a longitudinal sectional view on an enlarged scale through an outlet end of a bypass tube of a heat exchanger according to the present invention with a control device arranged in the area of the outlet end.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) Referring to the drawings, a heat exchanger 1 is schematically shown in a longitudinal section in FIG. 1 in a vertical arrangement. Such heat exchangers 1 are used for various chemical and petrochemical processes. The heat exchanger 1 comprises a plurality of heat transfer tubes 3 and a centrally arranged bypass tube 4, which are held each between a tube plate 5 of a gas inlet chamber 7 and a tube plate 6 of a gas outlet chamber 8. The respective tube plates 5, 6 are connected to a cylindrical jacket 2, within which a jacket space 9 is formed. The heat transfer tubes 3 and the bypass tube 4 are enclosed in the jacket space 9. A coolant 11 flows through the jacket space 9.

(5) The bypass tube 4 is configured with a larger diameter than the heat transfer tubes 3. Over a length of the bypass tube 4, the bypass tube 4 has heat insulation 23, on an inner tube wall 30. The heat insulation 23 is intended and configured for the bypass tube 4 not releasing essentially any heat while the process gas stream 14 is flowing through.

(6) As is indicated by an arrow, the coolant 11 flows into the jacket space 9 via at least one inlet pipe 10 arranged laterally at the cylindrical jacket 2 in the flow direction of the process gas stream 14 in front of the tube plate 6 of the gas outlet chamber 8. The coolant 11 leaves the jacket space 9 as a water/vapor mixture via at least one outlet pipe 12 arranged laterally on the cylindrical jacket 2 behind the tube plate 5 of the gas inlet chamber 7. The water/vapor mixture formed during the cooling is generated by indirect heat transfer via the jacket side of the heat transfer tubes 3.

(7) An inlet pipe 13, 13.1 is arranged in front of the tube plate 5 in the gas flow direction at the gas inlet chamber 7 laterally (13) or axially (13.1—as is indicated by dotted line only). As is indicated by an arrow, the process gas stream 14 flows through the inlet pipes 13, 13.1 into the gas inlet chamber 7 and from there into the ends of the heat transfer tubes 3 held in the tube plate 5 and into the end of the bypass tube 4, as is indicated by arrows.

(8) Indicated by dotted line only, a discharge pipe 15, 15.1 is arranged at the gas outlet chamber 8 laterally (15) or axially (15.1) behind the tube plate 6 in the gas flow direction. As is indicated by an arrow, the process gas stream 14 leaves the gas outlet chamber 8, which is connected to the ends of the heat transfer tubes 3 being held in the tube plate 6 and to the other end of the bypass tube 4, from which split process gas streams escape, as is indicated by arrows, through said discharge pipes 15, 15.1.

(9) A control device 16 is arranged at the outlet end 17 of the bypass tube 4. The control device 16 comprises a throttle valve (valve body) 18 in a valve housing 22 and a drive 19 arranged outside the heat exchanger 1. The drive 19 is connected to a shaft 21 and double joints 20 and to an integrated shaft end 27 of the throttle valve 18 and forms a powertrain. The throttle valve 18 is arranged adjustably with the connected double joints 20 and with the shaft end 27 by means of the drive 19 via the shaft 21.

(10) The double joints are intended essentially for compensating differences in thermal expansion between two bearings 25 for the respective integrated shaft end 27 of the throttle valve 18 in the valve housing 22 and a bearing 26 for the shaft 21. The respective bearing 26 is formed in a heat insulation 24, which is applied to an inner wall 29 of the valve housing 22. The bearing 26 is arranged in a wall 28 of the gas outlet chamber 8.

(11) The throttle valve (body) 18 is arranged rotatably at right angles to the gas flow direction in the valve housing 22. The heat insulation 24 applied to the inner wall 29 of the valve housing 22 is preferably configured as a lining.

(12) The valve housing 22 is configured as an extension of the bypass tube 4 with equal diameter if the existing installation conditions at the heat exchanger 1 are sufficient. In case of crowded installation conditions, a configuration of the valve housing 22 as is shown in FIG. 2 is to be preferred, and the extension of the bypass tube 4 over a conical attachment 31 is configured as a transition from the outlet end 17 of the bypass tube to an expanded diameter.

(13) The throttle valve 18 connected to the drive 19 is provided for setting a gas outlet temperature of the heat exchanger 1 to a certain temperature range by mixing the cooled process gas stream 14 from the heat transfer tubes 3 with the uncooled process gas stream from the bypass tube 4. A discharge speed (discharge rate) and a discharged quantity of the process gas stream 14 can be controlled with the throttle valve 18, which is arranged in the immediate vicinity of the outlet end 17 of the bypass tube 4 and adjustable by means of the drive 19 of the control device 16.

(14) The throttle valve 18 is made of a material resistant to high-temperature corrosion in the temperature range sensitive to high-temperature corrosion, which ranges from temperatures around 500° C. to an order of magnitude of about 850° C. The materials used as the control element for the throttle valve 18 are high-temperature-resistant or metal-dusting-resistant materials that have temperature stability and do not require special cooling. The valve housing 22 is manufactured from a material that is not necessarily fully resistant to high temperature corrosion, but is operated at a temperature outside of the range of high temperature corrosion. The valve housing 22 is protected by the insulation against high temperatures

(15) A ceramic material, which has high-temperature-resistant or metal-dusting-resistant properties with temperature stability, is used as a material for the throttle valve 18—particularly, the throttle valve body—is comprised of ceramic material or especially consists of a ceramic material.

(16) Components made of other materials are arranged heat insulated from the uncooled process gas stream 14 to the extent that these components can be used reliably according to the suitability of these materials.

(17) While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.