Fluidized bed heat exchanger

Abstract

A fluidized bed heat exchanger with a chamber (24) comprises a solid particles inlet port (22), a solid particles outlet port (30), arranged at a distance to the inlet port (22), means (46) for introducing a fluidizing gas from a bottom area into the chamber (24). The heat exchanger further comprises at least two heat transfer means (28) within the one chamber (24), each being provided with a heat transfer medium inlet port (42) and a heat transfer medium outlet port (44), wherein a first heat transfer means (28) is designed as a reheater and second heat transfer means (28) is designed as a superheater to achieve a heat transfer medium temperature and a heat transfer medium pressure above that of the reheater. At least one of the reheater or superheater is made of a multiplicity of heat transfer tubes arranged in a meandering fashion for conveying a heat transfer medium.

Claims

1. An apparatus comprising: a fluidized bed, wherein the fluidized bed includes a circulating fluidized bed reactor (10) with at least one outlet port (16) at its upper part, wherein said outlet port (16) allows a mixture of gas and solid particles exhausted from the circulating fluidized bed reactor (10) to flow into at least one associated separator (18) for separating solid particles from said gas, means (20) to transfer said separated solid particles into at least one fluidized bed heat exchanger, and return means to transport at least part of said solid particles back into the circulating fluidized bed reactor (10), wherein a) the fluidized bed reactor (10) and the fluidized bed heat exchanger (24) have one common wall (14w), b) the fluidized bed heat exchanger comprises b1) only one single chamber (24), wherein the only one single chamber (24) includes an interior area, wherein the interior area is enclosed and separated from the circulating fluidized bed reactor (10) such that no particles move from the reactor (10) to the chamber (24) without first moving through the separator (18), b2) at least one solid particles inlet port (22) arranged on the only one single chamber, b3) at least one solid particles outlet port (30) arranged on the only one single chamber at a distance and opposite to the at least one inlet port (22), b4) means (46) for introducing a fluidizing gas into a bottom area (24b) of said only one single chamber (24), b5) at least two distinct sets of heat transfer means (28, G1, G2) within said only one single chamber (24), b5i) each of said two heat transfer means (28, G1, G2) being provided with a respective heat transfer medium inlet port (42) and a respective heat transfer medium outlet port (44), wherein b5ii) the at least two heat transfer means (28, G1, G2) being arranged relative to the other in the only one single chamber allowing all solid particles to take a direct way through the at least two heat transfer means (28, G1, G2) from the at least one inlet port (22) to the at least one outlet port (30), wherein the at least two heat transfer means include b5iii) a first heat transfer means (28) that is designed as a reheater and a second heat transfer means (28) that is designed as a superheater to achieve a heat transfer medium temperature and a heat transfer medium pressure above that of the reheater.

2. An apparatus comprising: a circulating fluidized bed reactor, wherein the circulating fluidized bed reactor includes a fluidized bed, wherein the fluidized bed is operative to produce a mixture of hot gas and hot solid particles, wherein the circulating fluidized bed reactor includes a reactor chamber that houses the fluidized bed, wherein the reactor chamber includes an upper part, wherein the upper part of the reactor chamber includes a reactor outlet port, wherein the reactor outlet port is operative to pass all of the mixture of gas and solid particles produced by the circulating fluidized bed reactor from the reactor chamber, a cyclone separator, wherein the cyclone separator is in operative connection with the reactor outlet port, wherein the cyclone separator is operative to receive from the reactor chamber all of the mixture of gas and solid particles produced by the circulating fluidized bed reactor, wherein the cyclone separator is operative to separate the solid particles from the gas, wherein the cyclone separator includes a gas outlet from which the gas is exhausted from the cyclone separator and a particle outlet from which the particles leave the separator, a first conduit, wherein the first conduit is in operative connection with the particle outlet of the cyclone separator, a fluidized bed heat exchanger, wherein the fluidized bed heat exchanger includes only one single heat exchanger chamber, wherein the only one single fluidized bed heat exchanger chamber is in operative connection with the particle outlet of the cyclone separator through the first conduit, wherein the first conduit is operative to transfer a first portion constituting less than all of the separated solid particles from the cyclone separator into the only one single heat exchanger chamber wherein the solid particles are in operative contact with the fluidized bed heat exchanger, a second conduit, wherein the second conduit is in operative connection with the particle outlet of the cyclone separator, wherein the second conduit is operative to transport a second portion constituting a remainder of the separated solid particles from the cyclone separator not included in the first portion, into the reactor chamber, a support frame, wherein the support frame includes a horizontally extending upper base, wherein the upper base of the support frame includes a plurality of posts, wherein the posts extend downward from the upper base, wherein the circulating fluidized bed reactor and the cyclone separator are mounted in a horizontally disposed side-by-side vertically suspended manner from the plurality of posts, whereby the suspended mounting of the circulating fluidized bed reactor prevents damage due to expansion and constriction, wherein the fluidized bed heat exchanger and the fluidized bed are arranged in horizontally disposed side-by-side relation and are separated only by a single vertically extending common wall, wherein the single common wall includes a heat exchanger outlet port, wherein the heat exchanger outlet port is operative to pass solid particles from the only one single fluidized bed heat exchanger chamber to the reactor chamber.

3. The apparatus according to claim 2, wherein the reheater is constructed to allow a heat transfer medium temperature of up to 600 C.

4. The apparatus according to claim 2, wherein the reheater is constructed to allow a heat transfer medium pressure of up to 50 bar.

5. The apparatus according to claim 2, wherein the superheater is constructed to allow a heat transfer medium temperature of up to 600 C.

6. The apparatus according to claim 2, wherein the superheater is constructed to allow a heat transfer medium pressure of up to 190 bar.

7. The apparatus according to claim 2, wherein at least one of said reheater or superheater is made of a multiplicity of heat transfer tubes for conveying a heat transfer medium and arranged in a meandering fashion.

8. The apparatus according to claim 2, wherein the only one single chamber includes chamber walls, the chamber walls being at least partially water-cooled.

9. The apparatus according to claim 2, wherein the common wall (14w) is water-cooled.

10. The apparatus according to claim 2, and further comprising a syphon, wherein the syphon is in fluid connection with the particle outlet.

11. The apparatus according to claim 2, and further comprising a further fluidized bed, wherein the second conduit includes the further fluidized bed, wherein the further fluidized bed is comprised of a plurality of horizontally disposed nozzles on a bottom wall of the second conduit.

12. The apparatus according to claim 11, wherein the only one single heat exchanger chamber of the fluidized bed heat exchanger further includes a heat exchanger inlet port, wherein the heat exchanger inlet port is in operative connection with the first conduit, and at least one heat transfer tube.

13. The apparatus according to claim 12, wherein the solid particles transferred from the cyclone separator through the first conduit enter the only one single heat exchanger chamber through the heat exchanger inlet port, wherein the solid particles move through the only one single heat exchanger chamber in a direct path from the heat exchanger inlet port to the heat exchanger outlet port, wherein the heat exchanger outlet port is disposed directly horizontally of the heat exchanger inlet port and at a common vertical elevation with the heat exchanger inlet port, and wherein no vertically extending partition walls extend intermediate of the heat exchanger inlet port and the heat exchanger outlet port.

14. The apparatus according to claim 13, wherein the cyclone separator is in operative connection with a plurality of vertically extending separator posts, wherein the fluidized bed heat exchanger is vertically suspended from the cyclone separator by operative connection with the plurality of separator posts.

15. The apparatus according to claim 14, and further including a fluid source, wherein the single common wall includes a plurality of cooling tubes, wherein the plurality of cooling tubes are in operative connection with the fluid source and are operative to cool the single common wall.

16. The apparatus according to claim 15, wherein the cyclone separator includes at least two cyclone separators each in operative connection with the reactor chamber through respective reactor outlet ports, wherein each of the at least two cyclone separators include a respective gas outlet, and particle outlet, and further including at least two fluidized bed heat exchangers, wherein each of the at least two fluidized bed heat exchangers are in operative connection with a respective particle outlet of a respective cyclone separator and through a respective first conduit, wherein each of the at least two fluidized bed heat exchangers include a respective heat exchanger chamber, heat exchanger inlet port, at least one heat transfer tube, and heat exchanger outlet port.

17. The apparatus according to claim 16, wherein each of the at least two fluidized bed heat exchangers are arranged in operatively connected side-by-side relation and each fluidized bed heat exchanger is separated from each immediately adjacent fluidized bed heat exchanger by an intermediate water-cooled wall, and wherein each of the at least two fluidized bed heat exchangers are separated from the reactor chamber only by a respective single vertically extending common wall.

18. The apparatus according to claim 2, wherein the only one single heat exchanger chamber further includes a heat exchanger chamber fluidized bed, wherein the heat exchanger chamber fluidized bed is comprised of a plurality of horizontally disposed chamber nozzles on a bottom wall of the heat exchanger chamber.

19. The apparatus according to claim 18 further comprising: a conduit fluidized bed, wherein the conduit fluidized bed is comprised of a plurality of horizontally disposed conduit nozzles, wherein the plurality of conduit nozzles are in operative connection with at least one of the first conduit intermediate of the cyclone separator and the fluidized bed heat exchanger, and the second conduit intermediate of the cyclone separator and the circulating fluidized bed reactor chamber.

20. An apparatus comprising: a circulating fluidized bed reactor, wherein the circulating fluidized bed reactor includes a fluidized bed, wherein the fluidized bed is operative to produce a mixture of hot gas and hot solid particles, wherein the circulating fluidized bed reactor includes a reactor chamber that houses the fluidized bed, wherein the reactor chamber includes an upper part, wherein the upper part of the reactor chamber includes a reactor outlet port, wherein the reactor outlet port is operative to pass all of the mixture of gas and solid particles produced by the circulating fluidized bed reactor from the reactor chamber, a cyclone separator, wherein the cyclone separator is in operative connection with the reactor outlet port, wherein the cyclone separator is operative to receive from the reactor chamber all of the mixture of gas and solid particles produced by the circulating fluidized bed reactor, wherein the cyclone separator is operative to separate the solid particles from the gas, wherein the cyclone separator includes a gas outlet from which the gas is exhausted from the cyclone separator and a particle outlet from which the particles leave the separator, a first conduit, wherein the first conduit is in operative connection with the particle outlet of the cyclone separator, a fluidized bed heat exchanger, wherein the fluidized bed heat exchanger includes only one single heat exchanger chamber, wherein the only one single fluidized bed heat exchanger chamber is in operative connection with the particle outlet of the cyclone separator through the first conduit, wherein the first conduit is operative to transfer a first portion constituting less than all of the separated solid particles from the cyclone separator into the only one single heat exchanger chamber wherein the solid particles are in operative contact with the fluidized bed heat exchanger, wherein, before any of the solid particles produced by the circulating fluidized bed reactor are transferred into the only one single chamber of the fluidized bed heat exchanger, the solid particles that are transferred into the one single chamber are first transferred from the reactor chamber to the cyclone separator through the reactor outlet port, a second conduit, wherein the second conduit is in operative connection with the particle outlet of the cyclone separator, wherein the second conduit is operative to transport a second portion constituting a remainder of the separated solid particles from the cyclone separator not included in the first portion, into the reactor chamber, wherein the fluidized bed heat exchanger and the fluidized bed are arranged in horizontally disposed side-by-side relation and are separated only by a single vertically extending common wall, wherein the single common wall includes a heat exchanger outlet port, wherein the heat exchanger outlet port is operative to pass solid particles from the fluidized bed heat exchanger chamber to the reactor chamber.

21. An apparatus comprising: a circulating fluidized bed reactor, wherein the circulating fluidized bed reactor includes a fluidized bed, wherein the fluidized bed is operative to produce a mixture of hot gas and hot solid particles, wherein the circulating fluidized bed reactor includes a reactor chamber that houses the fluidized bed, wherein the reactor chamber includes an upper part, wherein the upper part of the reactor chamber includes a reactor outlet port, wherein the reactor outlet port is operative to pass all of the mixture of gas and solid particles produced by the circulating fluidized bed reactor from the reactor chamber, a cyclone separator, wherein the cyclone separator is in operative connection with the reactor outlet port, wherein the cyclone separator is operative to receive from the reactor chamber all of the mixture of gas and solid particles produced by the circulating fluidized bed reactor, wherein the cyclone separator is operative to separate the solid particles from the gas, wherein the cyclone separator includes a gas outlet in which the gas is exhausted from the cyclone separator and a particle outlet from which the particles leave the separator, a first conduit, wherein the first conduit is in operative connection with the particle outlet of the cyclone separator, a fluidized bed heat exchanger, wherein the fluidized bed heat exchanger includes only one single heat exchanger chamber, wherein the only one single fluidized bed heat exchanger chamber is in operative connection with the particle outlet of the cyclone separator through the first conduit, wherein the first conduit is operative to transfer a first portion constituting less than all of the separated solid particles from the cyclone separator into the only one single heat exchanger chamber wherein the solid particles are in operative contact with the fluidized bed heat exchanger, wherein the only one single heat exchanger chamber includes at least two distinct heat transfer means within the only one single heat exchanger chamber, wherein one of the at least two distinct heat transfer means comprises a reheater and the other of the at least two distinct heat transfer means comprises a superheater, wherein the superheater is operative to achieve a heat transfer medium temperature and a heat transfer medium pressure above the reheater, a second conduit, wherein the second conduit is in operative connection with the particle outlet of the cyclone separator, wherein the second conduit is operative to transport a second portion constituting a remainder of the separated solid particles from the cyclone separator not included in the first portion, into the reactor chamber, a support frame, wherein the support frame includes a horizontally extending upper base, wherein the upper base of the support frame includes a plurality of posts, wherein the posts extend downward from the upper base, wherein the circulating fluidized bed reactor and the cyclone separator are mounted in a horizontally disposed side-by-side vertically suspended manner from the plurality of posts, whereby the suspended mounting of the circulating fluidized bed reactor prevents damage due to expansion and constriction, wherein the fluidized bed heat exchanger and the fluidized bed are arranged in horizontally disposed side-by-side relation and are separated only by a single vertically extending common wall, wherein the single common wall includes a heat exchanger outlet port, wherein the heat exchanger outlet port is operative to pass solid particles from the only one single fluidized bed heat exchanger chamber to the reactor chamber.

22. The apparatus according to claim 21, wherein the only one single heat exchanger chamber of the fluidized bed heat exchanger includes at least one solid particles inlet port and at least one solid particles outlet port, wherein the at least one solid particles outlet port is arranged on the only one single heat exchanger chamber at a distance from and opposite to the at least one inlet port.

23. The apparatus according to claim 22, wherein the reheater and the superheater are arranged relative to each other to allow all solid particles to take a direct way through the reheater and the superheater from the at least one solid particles inlet port to the at least one solid particles outlet port.

24. An apparatus comprising: a circulating fluidized bed reactor, wherein the circulating fluidized bed reactor includes a fluidized bed, wherein the fluidized bed is operative to produce a mixture of hot gas and hot solid particles, wherein the circulating fluidized bed reactor includes a reactor chamber that houses the fluidized bed, wherein the reactor chamber includes an upper part, wherein the upper part of the reactor chamber includes a reactor outlet port, wherein the reactor outlet port is operative to pass all of the mixture of gas and solid particles produced by the circulating fluidized bed reactor from the reactor chamber, a cyclone separator, wherein the cyclone separator is in operative connection with the reactor outlet port, wherein the cyclone separator is operative to receive from the reactor chamber all of the mixture of gas and solid particles produced by the circulating fluidized bed reactor, wherein the cyclone separator is operative to separate the solid particles from the gas, wherein the cyclone separator includes a gas outlet in which the gas is exhausted from the cyclone separator and a particle outlet from which the particles leave the separator, a first conduit, wherein the first conduit is in operative connection with the particle outlet of the cyclone separator, a fluidized bed heat exchanger, wherein the fluidized bed heat exchanger includes only one single heat exchanger chamber, wherein the only one single fluidized bed heat exchanger chamber is in operative connection with the particle outlet of the cyclone separator through the first conduit, wherein the first conduit is operative to transfer a first portion constituting less than all of the separated solid particles from the cyclone separator into the only one single heat exchanger chamber wherein the solid particles are in operative contact with the fluidized bed heat exchanger, wherein before any of the solid particles produced by the circulating fluidized bed reactor are transferred into the only one single chamber of the fluidized bed heat exchanger, the solid particles that are transferred into the one single chamber are first transferred from the reactor chamber to the cyclone separator through the reactor outlet port, wherein the only one single heat exchanger chamber includes at least two distinct heat transfer means within the only one single heat exchanger chamber, wherein one of the at least two distinct heat transfer means comprises a reheater and the other of the heat transfer means comprises a superheater, wherein the superheater is operative to achieve a heat transfer medium temperature and a heat transfer medium pressure above the reheater, a solid particles inlet port and a solid particles outlet port, wherein the solid particles outlet port is arranged on the only one single heat exchanger chamber at a distance from and opposite to the inlet port, wherein the reheater and the superheater are arranged relative to each other in the only one single chamber to allow all solid particles to take a direct way through the reheater and the superheater from the solid particles inlet port to the solid particles outlet port, a second conduit, wherein the second conduit is in operative connection with the particle outlet of the cyclone separator, wherein the second conduit is operative to transport a second portion constituting a remainder of the separated solid particles from the cyclone separator not included in the first portion, into the reactor chamber, wherein the fluidized bed heat exchanger and the fluidized bed are arranged in horizontally disposed side-by-side relation and are separated only by a single vertically extending common wall, wherein the single wall is in direct connection with the heat exchanger outlet port, wherein the heat exchanger outlet port is operative to pass solid particles from the fluidized bed heat exchanger chamber to the reactor chamber.

25. Apparatus comprising: a circulating fluidized bed reactor, wherein the circulating fluidized bed reactor includes a fluidized bed, wherein the fluidized bed is operative to produce a mixture of hot gas and hot solid particles, wherein the circulating fluidized bed reactor includes a reactor chamber that houses the fluidized bed, wherein the reactor chamber includes an upper part, wherein the upper part of the reactor chamber includes a reactor outlet port, wherein the reactor outlet port is operative to pass all of the mixture of gas and solid particles produced by the circulating fluidized bed reactor from the reactor chamber, a cyclone separator, wherein the cyclone separator is in operative connection with the reactor outlet port, wherein the cyclone separator is operative to receive from the reactor chamber all of the mixture of gas and solid particles produced by the circulating fluidized bed reactor, wherein the cyclone separator is operative to separate the solid particles from the gas, wherein the cyclone separator includes a gas outlet in which the gas is exhausted from the cyclone separator and a particle outlet from which the particles leave the separator, a first conduit, wherein the first conduit is in operative connection with the particle outlet of the cyclone separator, a fluidized bed heat exchanger, wherein the fluidized bed heat exchanger includes only one single heat exchanger chamber, wherein the only one single fluidized bed heat exchanger chamber is in operative connection with the particle outlet of the cyclone separator through the first conduit, wherein the first conduit is operative to transfer a first portion constituting less than all of the separated solid particles from the cyclone separator into the only one single heat exchanger chamber wherein the solid particles are in operative contact with the fluidized bed heat exchanger, wherein the only one single heat exchanger chamber includes at least two distinct heat transfer means within the only one single heat exchanger chamber, wherein one of the at least two distinct heat transfer means comprises a reheater and the other of the heat transfer means comprises a superheater, wherein the superheater is operative to achieve a heat transfer medium temperature and a heat transfer medium pressure above the reheater, a solid particles inlet port and a solid particles outlet port, wherein the solid particles outlet port is arranged on the only one single heat exchanger chamber at a distance from and opposite to the inlet port, wherein the reheater and the superheater are arranged relative to each other in the only one single chamber to allow all solid particles to take a direct way through the reheater and the superheater from the solid particles inlet port to the solid particles outlet port, a second conduit, wherein the second conduit is in operative connection with the particle outlet of the cyclone separator, wherein the second conduit is operative to transport a second portion constituting a remainder of the separated solid particles from the cyclone separator not included in the first portion, into the reactor chamber, wherein any solid particles produced in the fluidized bed are caused to move from the reactor chamber to the cyclone separator and the solid particles are further caused to move from the cyclone separator to at least one of the fluidized bed heat exchanger and the reactor chamber, wherein any solid particles that enter into the fluidized bed heat exchanger must first pass through the cyclone separator, wherein the fluidized bed heat exchanger and the fluidized bed are arranged in horizontally disposed side-by-side relation and are separated only by a single vertically extending common wall, wherein the single wall is in direct connection with the heat exchanger outlet port, wherein the heat exchanger outlet port is operative to pass solid particles from the fluidized bed heat exchanger chamber to the reactor chamber.

26. Apparatus comprising: a circulating fluidized bed reactor, wherein the circulating fluidized bed reactor includes a fluidized bed, wherein the fluidized bed is operative to produce a mixture of hot gas and hot solid particles, wherein the circulating fluidized bed reactor includes a reactor chamber that houses the fluidized bed, wherein the reactor chamber includes an upper part, wherein the upper part of the reactor chamber includes a reactor outlet port, wherein the reactor outlet port is operative to pass all of the mixture of gas and solid particles produced by the circulating fluidized bed reactor from the reactor chamber, a cyclone separator, wherein the cyclone separator is in operative connection with the reactor outlet port, wherein the cyclone separator is operative to receive from the reactor chamber all of the mixture of gas and solid particles produced by the circulating fluidized bed reactor, wherein the cyclone separator is operative to separate the solid particles from the gas, wherein the cyclone separator includes a gas outlet in which the gas is exhausted from the cyclone separator and a particle outlet from which the particles leave the separator, a first conduit, wherein the first conduit is in operative connection with the particle outlet of the cyclone separator, a fluidized bed heat exchanger, wherein the fluidized bed heat exchanger includes only one single heat exchanger chamber, wherein the only one single fluidized bed heat exchanger chamber is in operative connection with the particle outlet of the cyclone separator through the first conduit, wherein the first conduit is operative to transfer a first portion constituting less than all of the separated solid particles from the cyclone separator into the only one single heat exchanger chamber wherein the solid particles are in operative contact with the fluidized bed heat exchanger, wherein any solid particles produced in the fluidized bed are caused to move from the reactor chamber to the cyclone separator and the solid particles are further caused to move from the cyclone separator to at least one of the fluidized bed heat exchanger and the reactor chamber, wherein any solid particles that enter into the fluidized bed heat exchanger must first pass through the cyclone separator, wherein the only one single heat exchanger chamber includes at least two distinct heat transfer means within the only one single heat exchanger chamber, wherein one of the at least two distinct heat transfer means comprises a reheater and the other of the heat transfer means comprises a superheater, wherein the superheater is operative to achieve a heat transfer medium temperature and a heat transfer medium pressure above the reheater, a solid particles inlet port and a solid particles outlet port, wherein the solid particles outlet port is arranged on the only one single heat exchanger chamber at a distance from and opposite to the inlet port, wherein the reheater and the superheater are arranged relative to each other in the only one single chamber to allow all solid particles to take a direct way through the reheater and the superheater from the solid particles inlet port to the solid particles outlet port, wherein the only one single heat exchanger chamber further includes a heat exchanger chamber fluidized bed, wherein the heat exchanger chamber fluidized bed is comprised of a plurality of horizontally disposed chamber nozzles on a bottom wall of the heat exchanger chamber, a second conduit, wherein the second conduit is in operative connection with the particle outlet of the cyclone separator, wherein the second conduit is operative to transport a second portion constituting a remainder of the separated solid particles from the cyclone separator not included in the first portion into the reactor chamber, a conduit fluidized bed, wherein the conduit fluidized bed is comprised of a plurality of horizontally disposed conduit nozzles, wherein the plurality of conduit nozzles are in operative connection with at least one of the first conduit intermediate of the cyclone separator and the fluidized bed heat exchanger, and the second conduit intermediate of the cyclone separator and the circulating fluidized bed reactor chamber, wherein the fluidized bed heat exchanger and the fluidized bed are arranged in horizontally disposed side-by-side relation and are separated only by a single vertically extending common wall, wherein the single wall is in direct connection with the heat exchanger outlet port, wherein the heat exchanger outlet port is operative to pass solid particles from the fluidized bed heat exchanger chamber to the reactor chamber.

Description

(1) The invention is now described with reference to the attached drawing, showingall in a very schematic wayin

(2) FIG. 1

(3) A general concept of a fluidized bed apparatus according to prior art

(4) FIG. 2

(5) A cross sectional view of a fluidized bed heat exchanger

(6) FIG. 3

(7) A top view on the FBHE 24 of FIG. 2 along line 3-3

(8) FIG. 4

(9) A cross sectional view of another embodiment of a fluidized bed heat exchanger

(10) FIG. 5

(11) A cross sectional view of further embodiment of a fluidized bed heat exchanger A with 2 groups of heat exchangers

(12) FIG. 6

(13) A top view on the FBHE of FIG. 5 along line 6-6

(14) FIG. 7

(15) A top view on a further example for a FBHE 24 with an amended inlet port

(16) FIG. 8a

(17) A cross sectional view of an FBHE with multiple nozzles sets in the bottom area

(18) FIG. 8b

(19) A cross sectional view of a syphon with multiple nozzles sets in the bottom area

(20) FIG. 9

(21) An general view of a fluidized bed apparatus mounted in a suspended manner

(22) FIG. 10

(23) A compact fluidized bed heat exchanger in a 3-dimensional view

(24) In the Figures identical an similar acting construction parts are identified by same numerals.

(25) FIG. 1 discloses the general concept of a fluidized bed apparatus and its main components according to the present invention.

(26) It comprises: A circulating fluidized bed reactor (CFBR) 10. Its lower part comprises a grate-like structure 12 through which air (arrow A1) is blown into a reactor chamber 14 via (not shown) nozzles, thus providing a fluidized bed (denseboardDB) above said grate 12, wherein said denseboard comprises a particulate material like coal, wood etc. to be burnt. The CFBR has two outlet ports 16 at opposite sides of its upper part, allowing a mixture of gas and solid particles exhausted from the CFBR to flow into associated separators 18, namely cyclone separators. The separators serve to separate solid particles from the gas. Transfer means 20, designed as ducts, extend from the lower end of each separator 18 downwardly and into an inlet port 22 along the ceiling 24c of a fluidized bed heat exchanger (FBHE) 24. A syphon-like tube construction 26 (U-shaped) extends from the lower end of each separator 18 into reactor chamber 14 and enters into chamber 14 shortly above grate 12 of said CFBR. The FBHE is equipped with (plate-like) heat transfer means 28 and an outlet port 30 merging into reactor chamber 14 at the same vertical height as tube construction 26.

(27) This concept belongs to prior art. Insofar details are not further illustrated as known to the skilled person.

(28) The invention includes one or more of the following features:

(29) According to FIG. 2 the fluidized bed heat exchanger 24 displays an inlet port 22 at its upper end (in FIG. 2: top left) and an outlet port 30 at its upper end (in FIG. 2: top right), i. e. opposite to each other. Said outlet port 30 provides return means for solid particles transported along transfer duct 20 into said FBHE and is provided within a common wall 14w of chamber 14 and FBHE 24.

(30) Outlet port 30 comprises multiple flow through openings, arranged in a horizontal row with a distance to each other along a corresponding wall section of said wall 14w.

(31) Said wall 14w is water-cooled, namely constructed of vertically extending tubes with fins running between adjacent tubes. The tubes are cooled by water fed through said tubes.

(32) The through holes having the function of discrete outlet ports are shown in FIG. 2 in a slightly inclined orientation, with a lower end towards the fluidized bed heat exchanger 24 and a higher end towards the fluidized bed reactor chamber 14.

(33) This inclined orientation (sloped outlet port 30) can be provided as part of a 3-dimensional profile (for example as a convexity 14w) of said wall 14w towards the inner space/chamber of the fluidized bed heat exchanger 24 as shown in dotted lines in FIG. 2 and characterized by numeral 30.

(34) FIG. 2 further shows the design and construction of heat transfer means 28 within the fluidized bed heat exchanger 24. In the Figure only one of said heat transfer means is shown. Further heat transfer means of equal design are placed at a distance to each other within FBHE 24 (perpendicular to the plane of projection).

(35) Steam is fed into said means 28 via a central feeding line 42, then flowing through the meandering tube (as shown), providing said means 28, and escaping via a common outlet line 44, allowing to take heat from the particulate material (symbolized by dots P) moving through FBHE 24 between inlet port 22 and outlet port 30.

(36) It is important that each of said means 28 is designed in a wall-like pattern and extending substantially parallel to the main flow direction of the solid particles on their way to and through the outlet port 30, symbolized in FIG. 2 by arrow S.

(37) All tubes 28 are connected to the same feeding line 42 and outlet line 44.

(38) The meandering tubes not only give the heat transfer means 28 a wall-like pattern but as well a grid-like structure to allow the particulate material to pass through as well in a horizontal direction.

(39) The horizontally extending sections of said tubes are about three times longer than the vertically extending sections (FIG. 2 is not drawn to scale). Adjacent horizontal sections extent to a distance to each other being about the tube diameter.

(40) As shown in FIG. 2 the heat transfer means 28 extent about more than 60% of the chamber height, being the distance between a chamber bottom 24b and a chamber sealing 24c. In the embodiment each of said wall-like heat transfer means 28 extends from slightly above bottom 24b to slightly below inlet port 22 and from slightly off wall 14w to slightly off opposite wall 24w.

(41) This allows to avoid any structural means within FBHE 24 which could otherwise urge the solid particles to meander within FBHE. In particular the new design allows to avoid any entrance chamber and/or return chamber for the particulate material to homogenize.

(42) In prior art devices a separate entrance chamber EC with a discrete partition wall is constructed between wall 24 w and adjacent part of heat transfer means 28 as well as a separate return chamber RC between wall 14 w and parts 28. These walls and chambers caused the stream of solid particles to flow up and down, which is now avoided with the new design without any partition walls.

(43) The particulate material may take a direct way from the inlet port 22 to the outlet port 30 (see arrow S) along the channels/gaps C formed between adjacent tubes (heat transfer means), as may be seen in FIG. 3.

(44) Fluidization of the particulate material within FBHE 24 is achieved by air nozzles 46 in the bottom area 24b. The particulate material is circulated by said purging means within FBHE 24 in order to optimize heat transfer from the hot solid particles P onto the steam flowing within tube like heat transfer means 28.

(45) The embodiment of FIG. 4 differs from that of FIGS. 2,3 insofar as two baffles 50, 52 extent from sealing 24c downwardly, ending shortly above heat transfer means 28. These baffles 50, 52 extend substantially perpendicular to a straight line between inlet port 22 and outlet port 30 (dotted line L).

(46) Both baffles 50, 52 extend between opposite walls of FBHE 24 (only one, namely 24s is shown), being the walls bridging said walls 14w, 24w. The baffles 50, 52 are arranged at a distance to each other.

(47) Each of said baffles 50, 52 comprise one opening symbolized by dotted line O to allow pressure adjustment (equalization) within the inner space of FBHE 24.

(48) The said baffle(s) 50, 52 may as well be designed like a curtain, fulfilling the same function as a continuous board, namely to urge the particulate material to flow through said channels C (FIG. 3) between adjacent heat transfer means 28 on their way between inlet port 22 and outlet port 30.

(49) In FIG. 4 outlet port 30 is extended, namely protruding into circulating fluidized bed reactor 10.

(50) In the embodiment according to FIG. 5 the multiplicity of heat transfer means 28 is split into two groups.

(51) A first group G1 is made of a number of heat transfer means 28 as shown in FIGS. 2, 3 with the exception that the horizontal extension between walls 24w, 14w is much shorter and ending about half the way between said walls 14w, 24w.

(52) This group G1 of multiple heat transfer tubes 28 connected to a common feeding line 42 and a common outlet line 44 is characterized by a feeding temperature of 480 C. and an outlet temperature of 560 C. of the heat transfer medium (steam) and an average steam pressure of 32 bar, thus fulfilling the function of a so called reheater.

(53) The second group G2 of several heat transfer means 28 is constructed the same way as group G1 but connected so separate inlet lines 42 and outlet lines 44 for said steam and designed to achieve a heat transfer medium temperature of between 510 C. (inlet temperature) and 565 C. (outlet temperature) as well as an average 170 bar pressure. This allows to use the tubes of group G2 as a so called superheater.

(54) As shown in FIG. 5 tubes of group G2 are arranged closer to the outlet port 30 and adjacent to wall 14w while tubes of group G1 are arranged adjacent to wall 24w with a distance between groups G1 and G2.

(55) FIG. 6 is a top view of FIG. 5 along line 6-6 in FIG. 5.

(56) The fluidized bed heat exchanger 24 according to FIG. 7 displays a different design around inlet port 22, which widens towards the inner space of chamber 24, wherein said widened section 22w is further inclined towards the bottom area 24b of FBHE 24 to provide a distributor means allowing the entering stream of solid particles to spread over substantially the full width of said inner space of chamber 24, wherein the width is defined by the distance of side wall 24s.

(57) This distributor means (section 22s) are arranged in a transition region defined by end section of inlet port 22 and the adjacent section of chamber 24, extending upstream of said heat transfer means 28 and extending over about of the chamber width.

(58) Ribs 22r protrude from the surface of said distributor 22s and are arranged in a star-like pattern.

(59) Again all walls 14w, 24w and 24s of said FBHE are made of water-cooled tubes with fins between adjacent tubes, symbolized in the right part of FIG. 7.

(60) FIG. 8a displays an FBHE 24 characterized by a modified bottom area 24b.

(61) Numerous air nozzles 46 are mounted within bottom 24b. Each nozzle comprises an outer end 46o, protruding downwardly from the outer surface of bottom 24b and an inner end 46i, protruding into the hollow space of FHBE 24 equipped with groups G1, G2 of heat exchange tubes 28.

(62) The nozzles 46 are assembled into five nozzle sets N1, N2, N3, N4 and N5, one behind the other in a row between walls 24w and 14w. All nozzles 46 of a nozzle set are commonly connected to a respective common gas channel 48. If air is fed along one of these channels all corresponding nozzles 46 will be activated to allow air to enter into FBHE 24.

(63) The arrangements of discrete nozzle sets N1 . . . N5 with discrete channels 48 make it possible to set different air pressure in different channels and accordingly to introduce air into the fluidized bed of solid particles within FBHE under different pressure at different areas to optimize homogenisation of the particles within the fluidized bed.

(64) A similar design may be used to improve the syphon-type seal 26 between separator 18 and FBHE 24 or reactor 10 respectively, as illustrated in FIG. 8b.

(65) A mixture of gas and solid particles like ash coming from separator 18 enters the inlet tube of the U-shaped syphon 26 in a downward direction, is then fluidized by a fluidized bed construction in a bottom area 26b of said inlet tube via nozzles 27, turns about 90 degrees, flows along an intermediate chamber section 26i, where further fluidization takes place, then turns up into an outlet tube of the U-shaped syphon 26, where further fluidization by nozzles 27 at the bottom area of said outlet tube may take place, before flowing along another U-shaped tube section and entering the CFBR 10 via a corresponding return line.

(66) Similar to the embodiment of FIG. 8a, the multiplicity of air nozzles 27 is split into three nozzles sets SN1, SN2 and SN3, each with a certain number of nozzles 27, and each coupled to a respective air duct D1, D2 and D3, feeding air to the respective nozzles 27 under same or different pressure.

(67) Similar to FIG. 8a the air ducts D1 . . . D3 have a funnel shape at their upper ends.

(68) FIG. 9 represents a fluidized bed apparatus wherein its main components, namely the CFBR 10, the FBHE 24 as well as corresponding separators 18 are mounted in a suspended manner to a central supporting structure, namely a frame 60. The frame 60 has the shape of an inverted U with its legs 60l fixed within ground GR.

(69) While the CFBR 10 and the separator 18 are each directly suspended from base 60b of frame structure 60 (by posts 62), the FBHE 24 is mounted in a suspended manner from separator 18.

(70) Mechanical stability of FBHE 24 is further achieved by said common, water-cooled wall 14w with CFBR 10.

(71) Because of the hanging structure thermal expansion and constriction take place at all components in the same direction and avoids mechanical as well as thermo-mechanical tensions between adjacent construction parts at most.

(72) To make the construction wear resistant, the fluidized bed heat exchanger has no refractory lining; all walls are water cooled metal walls.

(73) The hanging structure allows an integration of a syphon 26 with its return duct 26r without transferring mechanical forces or moments between the respective construction parts.

(74) According to FIG. 9 the lowermost point LP1 of outlet port 30 of fluidized bed heat exchanger 24 enters the circulating fluidized bed reactor 10 at a height of >0.15 L, calculated from the lowermost end of the axial length L of CFBR 10. The lowermost end is defined by grate 12 of the fluidized bed. The minimum distance of >0.1 L, better >0.2 L, allows to place the return means 30 out of the so called denseboard DB and avoids the risk of any backflow of solid particles from the fluidized bed within reactor 10 into the associated construction elements like FBHE 24. This feature may be combined with sloped outlet ports 30 as disclosed in FIG. 2 or sloped return ducts 26r.

(75) The lowermost point of return duct 26r of syphon 26 enters the CFBR at a height of the denseboard DB, close to grate 12 and below outlet port 30.

(76) This positioning of the two outlet ports/return means 30,26r to each other is an important combined feature valid for various applications.

(77) In case of an apparatus comprising more than one separator 18, for example 3 separators, FIG. 10 discloses an embodiment with three corresponding fluidized bed heat exchangers 24.1, 24.2, 24.3 which are mechanically connected to provide one common fluidized bed heat exchanger 24 of corresponding, suitable size, with water-cooled intermediate walls 24i. Again: all three wall sections 14w of the common heat exchanger 24 are part of the reactor wall 14, i.e. a common water-cooled wall with integrated outlet openings 30.

(78) Walls 14i, 14w are made of metal tubes, welded to each other and connected with a fluid source to feed cooling water through said tubes.