Agitator

Information

  • Patent Grant
  • 6439756
  • Patent Number
    6,439,756
  • Date Filed
    Monday, May 1, 2000
    24 years ago
  • Date Issued
    Tuesday, August 27, 2002
    22 years ago
Abstract
An agitator for agitating liquids in an agitator vessel for suspending solids and dispersing gas in a liquid, in particular in an absorber of a flue gas desulfurizing plant, includes an agitator vessel, an agitator shaft extending into the agitator vessel, and an agitating propeller mounted to the agitator shaft within the agitator vessel. The agitator shaft is hollow to define an interior space for conducting gas into the agitator vessel and injecting gas on the pressure side of the agitating propeller into the liquid.
Description




CROSS-REFERENCES TO RELATED APPLICATIONS




This application claims the priority of German Patent Application Serial No. 299 09 312.3, filed May 27, 1999, the subject matter of which is incorporated herein by reference.




BACKGROUND OF THE INVENTION




The present invention relates to an agitator for agitating liquids in an agitator vessel, with a gas being added to the liquid, in particular for suspending solids and dispersing gas in the liquid in flue gas desulfurizing plants.




Gas injection pipes or gas injection lances have been used to date for gassing of absorbers of flue gas desulfurizing plants and formed as simple, horizontal pipes with bores or vertical pipes through which gas, normally air, is injected. These pipes or lances are, however, incapable to efficiently distribute high gas rates.




SUMMARY OF THE INVENTION




It is thus an object of the present invention to provide an improved agitator, obviating the afore-stated drawbacks.




In particular, it is an object of the present invention to provide an improved agitator by which higher gas rates can be efficiently distributed in the liquid in the agitator vessel, and the injected gas can be pre-dispersed by the agitator.




These objects, and others which will become apparent hereinafter, are attained in accordance with one embodiment of the present invention by providing an agitator vessel; an agitator shaft extending into the agitator vessel, with the agitator shaft being hollow to define an interior space for conducting gas into the agitator vessel; and an agitating propeller mounted to the agitator shaft within the agitator vessel.




According to another embodiment, the agitator is provided with a hollow hub which is connected in fixed rotative engagement with the agitator shaft and through which gas is conducted for introduction into the agitator vessel.




According to still another embodiment, the agitator shaft is provided with a plurality of pipes which are securely fixed to the agitator shaft and to which gas is directly supplied from outside the agitator vessel.




Suitably, the hollow agitator shaft and the hollow hub are provided in the area of their vessel-proximal ends with transverse bores for introduction of gases into the agitator vessel.




Advantageously, a gas injection device is arranged in the area of the vessel-proximal end of the agitator shaft or the hub.




The gas injection device may be configured in the form of a plurality of pipes which extend, in particular radial, to the longitudinal axis of the agitator shaft or hub, and are in communication with the interior space of the agitator shaft or hub or the pipes connected to the agitator shaft.




According to another variation, the gas injection device is configured in the form of a chamber which surrounds the agitator shaft or the hub and is in communication with the interior space of the agitator shaft or the hub.




Preferably, the gas injection device in the form of the pipes or the chamber has outlet openings through which the gas flows into the agitator vessel and which are located on a diameter which is approximately 35 to 75% of the diameter of the agitating propeller. It is further advantageous to configure the outlet openings of the pipes and the chamber on the backside as relating to the rotation direction of the gas injection device, i.e. on the underpressure side of the pipes or the chamber. The outlet openings of the gas injection device for introducing gas into the agitator vessel are arranged, preferably, on the pressure side of the agitating propeller.




In order to prevent a recoil of gas back to the agitating propeller, the axial distance of the gas injection device to the agitating propeller is suitable approximately 25% to 75% of a diameter of the propeller.




According to another feature of the present invention, a stationary distributor head can be provided for the supply of gas.




Advantageously, the hub is configured only in the area of the inner end of the solid agitator shaft, with the gas being directly supplied to the hollow hub via a pipe which traverses the wall of the agitator vessel.











BRIEF DESCRIPTION OF THE DRAWING




The above and other objects, features and advantages of the present invention will be more readily apparent upon reading the following description of a preferred exemplified embodiment of the invention with reference to the accompanying drawing, in which:





FIG. 1

is a schematic, partially sectional view of a first embodiment of an agitator according to the invention;





FIG. 2

is a schematic, partially sectional view of a second embodiment of an agitator according to the invention;





FIG. 3

is a schematic, partially sectional view of a third embodiment of an agitator according to the invention;





FIG. 4

is a schematic end view of a gas injection device for introduction of gas into a vessel of the agitator;





FIG. 5

is a schematic end view of a variation of the gas injection device; and





FIG. 6

is a schematic, partially sectional view of a fourth embodiment of an agitator according to the invention.











DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS




Throughout all the Figures, same or corresponding elements are generally indicated by same reference numerals.




Turning now to the drawing, and in particular to

FIG. 1

, there is shown a schematic, partially sectional view of a first embodiment of an agitator according to the invention, generally designated by reference numeral


10


and mounted in the interior of an agitator vessel


12


, e.g. an absorber of a flue gas desulfurizing plant, containing a liquid. Heretofore, such absorbers use horizontal gassing pipes or gassing lances which are, however, incapable to efficiently distribute gas at high gas rates. It is therefore suitable to utilize an agitator to carry out a pre-dispersion of the gas that is injected in the liquid of the absorber.




The agitator


10


includes an agitator shaft


14


which can be rotated by an external drive (not shown) and projects from outside through the wall of the agitator vessel


12


into the interior of the agitator vessel


12


. The agitator shaft


14


is defined by a longitudinal axis which extends in assembled state of the agitator


10


in a substantially horizontal orientation. Although not shown in drawing, the longitudinal axis of the agitator shaft


14


may also extend at a downward inclination of about 15°.




An axial conveyor in the form of an agitating propeller


16


is mounted to the agitator shaft


14


in the interior of the agitator vessel


12


and connected in fixed rotative engagement with the agitator shaft


14


for conveying the contents being agitated in a direction of arrow P.




As shown in

FIG. 1

, the agitator shaft


14


is hollow and coupled outside the agitator vessel


12


with a stationary distributor head


18


to which gas, for example air, from a gas source is supplied via a feed pipe


20


and by means of a fan (not shown). The agitator shaft


14


has radial bores


22


in the area of the distributor head


18


for introduction of gas from the distributor head


18


into the interior of the agitator shaft


14


. Appropriate seals


24


, for example lip seals, labyrinth seals or gap seals, are incorporated between the stationary distributor head


18


and the rotatable agitator shaft


14


as well as between the agitator shaft


14


and the wall of the agitator vessel


12


to prevent escape of gas.




The agitator shaft


14


has a closed inner end


36


and is provided in the area of the inner end


36


with through-openings


26


which are formed in the cylinder wall of the agitator shaft


14


and extend transversely to its longitudinal axis. Mounted in fixed rotative engagement in proximity of the inner end


36


of the agitator shaft


14


is a gas injection device, generally designated by reference numeral


28


, for introduction of gas, supplied via the hollow agitator shaft


14


, into the liquid in the agitator vessel


12


. As the gas injection device


28


is connected in fixed rotative engagement with the agitator shaft


14


, a structural unit, comprised of the agitator shaft


14


, the propeller


16


and the gas injection device


28


, is realized, which rotates as a unit. The gas injection device


28


may be designed in various ways, two of which will be described in more detail furtherbelow with reference to

FIGS. 4 and 5

.




As further shown in

FIG. 1

, the agitating propeller


16


has a center plane which is spaced from the center plane of the gas injection device


28


by an axial distance A which ranges suitably about 25 to 75% of a diameter of the propeller


16


so that a possible recoil of gas cannot impair the action of the axial conveyor, i.e. of the propeller


16


.




Turning now to

FIG. 2

, there is shown a further embodiment of an agitator


10


according to the present invention. Parts corresponding with those in

FIG. 1

are generally denoted by identical reference numerals and not explained again. In this embodiment, provision is made for a solid agitator shaft


15


and a hollow hub


34


, which is in fixed rotative engagement with the agitator shaft


15


and the propeller


16


, for conducting gas supplied from the feed pipe


20


and via a ring space


40


demarcated between the agitator shaft


15


and the stationary distributor head


18


arranged outside the agitator vessel


12


. The distributor head


18


is coupled with the agitator shaft


15


which is guided through the distributor head


18


. Seals


24


are incorporated between the distributor head


18


and the agitator shaft


15


to prevent escape of gas. Mounted to the inner end of the agitator shaft


15


is the axial conveyor in the form of the agitating propeller


16


which extends radially in to the interior of the vessel


12


via suitable bores in the hub


34


and conveys liquid in the vessel


12


in the direction of the arrow P.




The hub


34


extends in surrounding concentric relationship to the agitator shaft


15


and has an inner end


46


and an outer end


42


which is in overlapping disposition with an inner end


44


of the distributor head


18


. In the embodiment of

FIG. 2

, the distributor head


18


projects slightly through the wall of the agitator vessel


12


into the interior of the agitator vessel


12


. A suitable seal


24


is incorporated between the outer end


42


of the hub


34


and the inner end


44


of the distributor head


18


. The inner end


46


of the hub


34


is closed, and the hollow hub


34


is provided in the area of the inner end


46


with radial bores


38


formed in the cylindrical wall of the hub


34


. Mounted in fixed rotative engagement to the inner end


46


of the hub


34


and in alignment with the bores


38


is the gas injection device


28


in a configuration, as will be described with reference to

FIGS. 4 and 5

. Thus, the gas injection device


28


forms with the hub


34


and the propeller


16


again a structural unit which rotates as a unit. Gas supplied through the hollow hub


34


enters via the radial bores


38


into the gas injection device


28


, and the gas is injected into the liquid in the agitator vessel


12


through the outlet openings


32


of the gas injection device


28


.




As shown schematically in

FIG. 4

, the gas injection device


28


may include four radial pipes


30


extending out from the agitator shaft


14


or the hub


34


. Persons skilled in the prior art will understand that although

FIG. 4

shows the provision of four pipes


30


, it is certainly within the scope of the present invention to provide more or less than four pipes


30


. In the illustrated example of

FIG. 4

, the pipes


30


have beveled free ends, for example at an angle of 45° with respect to their longitudinal axis, thereby forming beveled outlet openings


32


in fluid communication with the bores


26


or bores


38


of the agitator shaft


14


or the hub


34


, respectively, for injection of gas. Although not shown in detail, it is certainly possible to close the outer free end of the pipes


30


and to provide in the cylinder wall of the pipes


30


one or more bores to form the outlet openings. The outlet openings


32


of the pipes


30


are suitably located on a diameter of a circle which is greater than the diameter of the agitator shaft


14


or the hub


34


whereby, preferably, the diameter of the circle, upon which the centers of the outlet openings


32


lie, is about 35% to 75% of the diameter of the propeller


16


.




The outlet openings


32


of the pipes


30


are disposed, relative to the rotation direction R of the gas injection device


28


, on the backside of the pipes


30


, i.e. on the underpressure side of the gas channels in the pipes


30


, so that an underpressure corresponding to the dynamic pressure in front of the pipes, is generated which reduces a possible pressure loss in the gas supply or which can be exploited for self-aspiration (without external fan) upon small liquid coverings of the outlet openings


32


.




Another example of the gas injection device


28


is shown in FIG.


5


and has the form of, for example, a triangular, chamber


48


which surrounds the vessel-proximal end of the hollow agitator shaft


14


according to the agitator


10


of

FIG. 1

or the hollow hub


34


according to the agitator


10


of

FIG. 2

, and is connected in fixed rotative engagement with the agitator shaft


14


or the hub


34


. The axial width of the chamber


48


in the direction of the longitudinal axis of the agitator shaft


14


ore the hub


34


is so selected that the chamber


48


covers at least the radial bores


26


of the agitator shaft


14


or the radial bores


38


of the hub


34


. Suitably, the width of the chamber


48


is, however, greater than the diameter of these bores


22


or


38


.




In the non-limiting example of

FIG. 5

, the chamber


48


has three outlet openings


32


through which gas, conducted through the agitator shaft


14


or the hub


34


and entering through the bores


26


of the agitator shaft


14


or bores


38


of the hub


34


into the chamber


48


, is injected into the agitator vessel


12


. The outlet openings


32


may extend over the entire axial width of the chamber


48


and are located with respect to the rotation direction R of the gas injection device


28


on the backside of the chamber


48


so as to generate the underpressure as already described above in conjunction with the embodiment of FIG.


4


.




Like in the gas injection device according to

FIG. 4

, the axial distance A between the center plane of the propeller


16


and the axial center plane of the chamber


48


is about 25% to 75% of the diameter of the propeller


16


. Also the centers of the outlet openings


32


of the chamber


48


are located on a diameter which is about 35% to 75% of the propeller diameter.




In the embodiment of the agitator


10


according to

FIG. 1

, gas is conducted from a fan (not shown) via the feed pipe


20


, the distributor head


18


, the radial bores


22


, the hollow agitator shaft


14


, and the radial bores


26


in the agitator shaft


14


into the gas injection device


28


(either through pipes


30


of

FIG. 4

or through the chamber


48


of

FIG. 5

) and is injected through the outlet openings


32


into the liquid in the agitator vessel


12


.




In the embodiment of the agitator


10


of

FIG. 2

, gas is introduced by means of a fan (not shown) via the feed pipe


20


, the ring space


40


between the agitator shaft


15


and the distributor head


18


, the hollow hub


34


and the radial bores


38


of the hub


34


into the gas injection device


28


(either pipes


30


of

FIG. 4

or the chamber


48


of

FIG. 5

) is injected through its outlet openings


32


into the liquid in the agitator vessel


12


.




The gas injection device


28


, having a radial distance A from the propeller


16


, is positioned with respect to the peripheral wall of the agitator vessel


12


inwards from the propeller


16


on the pressure side of the latter. Thus, gas is introduced from outside through the hollow agitator shaft


14


in the embodiment of the agitator of

FIG. 1

, or through the hollow hub


34


in the embodiment of the agitator of

FIG. 2

, into the agitator vessel


12


and supplied by means of the gas injection device


28


on the pressure side of the propeller


16


to the liquid contained in the agitator vessel


12


.




The propeller


16


generates a sufficiently strong liquid jet to suspend solids in the liquid and, at the same time, to disperse the gas in the liquid.





FIG. 3

shows schematically a side view of still another embodiment of an agitator


10


according to the present invention. Parts corresponding with those in

FIG. 2

are denoted by identical reference numerals and not explained again. In the embodiment, provision is made again for a solid agitator shaft


15


and an axial conveyor in the form of the propeller


16


which is mounted in fixed rotative engagement to the agitator shaft


15


. In a same manner as in the embodiment of

FIG. 2

, the inner end


44


of the stationary distributor head


18


projects slightly into the interior of the agitator vessel


12


. The inner end


44


of the distributor head


18


is closed by an end wall


58


which is connected in fixed rotative engagement with the agitator shaft


15


and axially overlaps the inner end


44


of the distributor head


18


. A suitable seal


24


is disposed between the end wall


58


and the inner end


44


of the distributor head


18


to prevent escape of gas. A further seal


24


is arranged between the distributor head


18


and the shaft


15


.




Arranged on the outer circumference of the agitator shaft


15


are several, for example four, pipes


52


and securely fixed to the agitator shaft


15


in substantially parallel disposition to the agitator shaft


15


. With their outer ends


60


, the pipes


52


project through the wall


58


into the ring space


40


of the stationary distributor head


18


. The pipes


52


are bent radially outwards, essentially at a right angle to the longitudinal axis of the pipes


52


, in the area of the inner vessel-proximal end


54


of the agitator shaft


15


and thus form radial pipe sections


56


having free ends forming the outlet openings


32


for introduction of gas into the agitator vessel


12


and thus constituting the gas injection device


28


.




The configuration of these outlet openings


32


and their disposition is the same as the outlet openings


32


of the pipes according to

FIG. 1

or FIG.


2


. Also the center plane of the pipe sections


56


has the axial distance A from the center plane of the agitating propeller


16


.




Turning now to

FIG. 6

, there is shown yet another embodiment of an agitator


10


according to the present invention. In this embodiment, the hub


34


is formed only in the area of the inner end


54


of the solid agitator shaft


15


and connected in suitable manner, for example through welding or by means of screws, with this inner end


54


of the agitator shaft


15


. The vessel-proximal end


46


of the hollow hub


34


is open and the feed pipe


20


terminates in this end


46


, with a suitable seal


24


, for example a lip seal or a labyrinth seal or the like, being disposed between the rotating hub


34


and the stationary feed pipe


20


. It is however also possible to provide a seal by means of a defined gap, thereby omitting the need for a particular seal.




Unlike the above-described embodiments, the pipe


20


is guided in the embodiment of

FIG. 6

from outside through the wall of the agitator vessel


12


. The pipe


20


suitably extends radially into the agitator vessel


12


and is then so curved that its end section


21


is again directed to the outside toward the wall of the agitator vessel for connection from inside into the hollow hub


34


. In this manner, gas is introduced and injected via the feed pipe


20


,


21


directly into the hollow hub


34


.




The hub


34


according to

FIG. 6

is provided with the already described gas injection device


28


which in turn includes the pipes


30


according to the variation of

FIG. 4

, or the chamber


48


according to the variation of FIG.


5


.




The pipes


30


,


52


and


56


may have a circular cross section, rectangular cross section or any other suitable cross section. The chamber


48


according to

FIG. 5

may also have a rectangular cross section or any other suitable cross section.




Optionally, the gas injection device may be omitted altogether, and gas may be injected directly into the agitator vessel. Although this may be sufficient in some to attain a good dispersion of gas in conjunction with the flow generated by the propeller


16


, the provision of the gas injection device


28


is preferred and realizes better results. The distributor head


18


may also be integrated in the wall of the agitator


10


or incorporated in its entirety in the interior of the agitator vessel


12


. In this case, the feed pipe


20


is guided through the wall of the agitator vessel


12


and connected to the distributor head


18


.




The agitator according to the invention realizes higher material transfer rates and higher gas throughputs than was possible to date with conventional gas injections devices.




While the invention has been illustrated and described as embodied in an agitator, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.




What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:



Claims
  • 1. An agitator for agitating liquids, with a gas being added to the liquid, in particular for suspending solids and dispersing gas in the liquid in flue gas desulfurizing plants, said agitator comprising:an agitator shaft extending into an agitator vessel, said agitator shaft being hollow to define an interior space for conducting gas into the agitator vessel; and an agitating propeller mounted to the agitator shaft within the agitator vessel; and a gas injection device connected to the one end in fixed rotative engagement with the agitator shaft for introducing gas into the agitator vessel at an axial distance downstream of the agitating propeller in the conveying direction of the liquid.
  • 2. The agitator of claim 1 wherein the hollow agitator shaft has one end disposed in the agitator vessel and formed with transverse bores for discharge of gas into the agitator vessel.
  • 3. The agitator of claim 2 wherein the gas injection device includes a plurality of pipes extending out from the agitator shaft within the agitator vessel and fluidly connected with the interior space of the hollow agitator shaft.
  • 4. The agitator of claim 3 wherein the pipes extend radially from the agitator shaft.
  • 5. The agitator of claim 3 wherein the agitating propeller defines a diameter, each of said pipes terminating in an outlet opening, with the outlet openings of the pipes being located on a diameter which is about 35% to 75% of the diameter of the agitating propeller.
  • 6. The agitator of claim 5 wherein the gas injection device rotates in a rotation direction, said outlet openings of the pipes being positioned on an underpressure side of the pipes with respect to the rotation direction of the gas injection device.
  • 7. The agitator of claim 3 wherein the gas injection device includes a chamber which surrounds the agitator shaft and communicates with the interior space of the agitator shaft.
  • 8. The agitator of claim 7 wherein the agitating propeller defines a diameter, said chamber having outlet openings which are located on a diameter which is about 35% to 75% of the diameter of the agitating propeller.
  • 9. The agitator of claim 7 wherein the gas injection device rotates in a rotation direction, said outlet openings of the chamber being positioned on a underpressure side of the pipes with respect to the rotation direction of the gas injection device.
  • 10. The agitator of claim 3 wherein the agitating propeller is defined by a center plane and has a diameter, said gas injection device being defined by a center plane which is spaced from the center plane of the agitating propeller by an axial distance which is about 25% to 75% of the diameter of the agitating propeller.
  • 11. The agitator of claim 3 wherein the gas injection device is arranged on the pressure side of the agitating propeller for injecting gas into the agitator vessel.
  • 12. The agitator of claim 1, and further comprising a stationary distributor head fluidly connected with the interior space of the agitator shaft for supply of gas.
  • 13. The agitator of claim 12, wherein the agitator shaft has radial bores for fluidly connecting the interior space of the agitator shaft with the distributor head.
  • 14. An agitator for agitating liquids, with a gas being added to the liquid, in particular for suspending solids and dispersing gas in the liquid in flue gas desulfurizing plants, said agitator comprising:an agitator shaft extending into an agitator vessel; a hub connected in fixed rotative engagement with the agitator shaft for conducting gas into the agitator vessel, said hub being hollow to define an interior space; an agitating propeller mounted to the agitator shaft within the agitator vessel for axially moving a liquid in the agitator vessel in a conveying direction; and a gas injection device, connected in fixed rotative engagement to the hub to rotate conjointly with the hub, for injecting gas into the interior of the agitator vessel, wherein the gas injection device is disposed at an axial distance downstream of the agitating propeller in the conveying direction of the liquid.
  • 15. The agitator of claim 14 wherein the agitator shaft has one end positioned in the agitator vessel, said hub being configured in the area of the one end of the agitator shaft, and further comprising a pipe guided from outside through a wall of the agitator vessel and connected to the hub for direct supply of gas to the hub.
  • 16. The agitator of claim 14 wherein the hub is formed with transverse bores for introduction of gas into the agitator vessel.
  • 17. The agitator of claim 14 wherein the gas injection device includes a plurality of pipes extending out from the hub within the agitator vessel and fluidly connected with the interior space of the hub.
  • 18. The agitator of claim 17 wherein the pipes extend radially from the agitator shaft.
  • 19. The agitator of claim 17 wherein the agitating propeller defines a diameter, each of said pipes terminating in an outlet opening, with the outlet openings of the pipes being located on a diameter which is about 35% to 75% of the diameter of the agitating propeller.
  • 20. The agitator of claim 19 wherein the gas injection device rotates in a rotation direction, said outlet openings of the pipes being positioned on an underpressure side of the pipes with respect to the rotation direction of the gas injection device.
  • 21. The agitator of claim 14 wherein the gas injection device includes a chamber which surrounds the hub and communicates with the interior space of the hub.
  • 22. The agitator of claim 14 wherein the agitating propeller is defined by a center plane and has a diameter, said gas injection device being defined by a center plane which is spaced from the center plane of the agitating propeller by an axial distance which is about 25% to 75% of the diameter of the agitating propeller.
  • 23. The agitator of claim 14 wherein the gas injection device is arranged on a pressure side of the agitating propeller.
  • 24. The agitator of claim 14, and further comprising a stationary distributor head fluidly connected with the interior space of the hub for supply of gas.
  • 25. The agitator of claim 24, wherein the agitator shaft and the distributor head define a ring space for fluidly connecting the interior space of the hub with the distributor head.
  • 26. The agitator of claim 14, and further comprising a gas source in communication with the gas injection device for supplying gas to the gas injection device.
  • 27. The agitator of claim 14 wherein the agitator shaft is solid.
  • 28. An agitator for agitating liquids, with a gas being added to the liquid, in particular for suspending solids and dispersing gas in the liquid in flue gas desulfurizing plants, said agitator comprising:an agitator shaft extending into an agitator vessel; a plurality of pipes connected in a fixed rotative engagement to the agitation shaft and disposed about an outer circumference of and extending longitudinally in the direction of the agitator shaft for conduction of gas and introduction into the agitator vessel; and an agitating propeller mounted to the agitator shaft within the agitator vessel wherein the pipes end at an axial distance downstream of the agitating propeller in a conveying direction of the liquid.
  • 29. The agitator of claim 28 wherein the agitator shaft is solid and has one end located in the agitator vessel, and further comprising a gas injection device connected in an area of the one end in fixed rotative engagement with the agitator shaft for introducing gas into the agitator vessel.
  • 30. The agitator of claim 29 wherein the gas injection device includes a plurality of pipe sections which are fluidly connected to the pipes in one-to-one correspondence.
  • 31. The agitator of claim 30 wherein the pipe sections and the pipes are formed in one piece with one another.
  • 32. The agitator of claim 30 wherein the pipe sections extend in a radial direction.
  • 33. The agitator of claim 30 wherein the agitating propeller defines a diameter, each of said pipe sections terminating in an outlet opening, with the outlet openings of the pipe sections being located on a diameter which is about 35% to 75% of the diameter of the agitating propeller.
  • 34. The agitator of claim 33 wherein the gas injection device rotates in a rotation direction, said outlet openings of the pipe sections being positioned on a underpressure side of the pipe sections with respect to the rotation direction of the gas injection device.
  • 35. The agitator of claim 29 wherein the agitating propeller is defined by a center plane and has a diameter, said gas injection device being defined by a center plane which is spaced from the center plane of the agitating propeller by an axial distance which is about 25% to 75% of the diameter of the agitating propeller.
  • 36. The agitator of claim 29 wherein the gas injection device is arranged on the pressure side of the agitating propeller for injecting gas into the agitator vessel.
  • 37. The agitator of claim 28, and further comprising a stationary distributor head fluidly connected to the pipes for supply of gas.
  • 38. An agitator, comprising:a gas-conducting receiving gas from a gas source and having an interior space terminating in an outlet means for introducing a gas into a vessel containing a liquid; and a propeller mounted to the gas-conducting device for stirring the liquid and dispersing the gas in the liquid wherein the outlet means is disposed at an axial distance downstream of the propeller in a conveying direction of the liquid.
  • 39. The agitator of claim 38 wherein the gas-conducting device is a hollow shaft extending into the agitator vessel and defining an interior space for conducting the gas and discharge through the outlet means said propeller being mounted onto the shaft.
  • 40. The agitator of claim 38 wherein the gas-conducting device includes a solid shaft extending into the vessel, and a hollow hub connected inside the vessel in fixed rotative engagement with the shaft and surrounding the shaft at a distance thereto to define an interior space for conducting the gas through the outlet means into the vessel, said propeller being mounted onto the shaft.
  • 41. The agitator of claim 38 wherein the gas-conducting device includes a solid shaft extending into the vessel, and a plurality of pipes formed with the outlet means, said pipes fluidly communicating with the gas source and connected about an outer circumference of and extending longitudinally in the direction of the shaft for conduction of gas and introduction through the outlet means into the vessel, said propeller being mounted onto the shaft.
  • 42. The agitator of claim 38 wherein the gas-conducting device includes a solid shaft extending into the vessel, a hollow hub mounted to the shaft inside the vessel and formed with the outlet means, and a pipe guided from outside through a wall of the vessel and connected to the hub for direct supply of gas to the hub.
  • 43. The agitator of claim 38, and further comprising a gas injection device connected in fixed rotative engagement to the gas-conducting device in fluid communication with the outlet means.
  • 44. The agitator of claim 43 wherein the gas injection device includes a plurality of pipes extending out from the gas-conducting device and fluidly connected with the interior space of the gas-conducting device.
  • 45. The agitator of claim 44 wherein the pipes extend radially from the gas-conducting device.
  • 46. The agitator of claim 43 wherein the gas injection device includes a chamber which surrounds the gas-conducting device and communicates with the interior space of the gas-conducting device.
  • 47. The agitator of claim 46 wherein the propeller defines a diameter, said chamber having outlet openings which are in fluid communication with the outlet means of the gas-conducting device and located on a diameter which is about 35% to 75% of the diameter of the propeller.
  • 48. The agitator of claim 47 wherein the gas injection device rotates in a rotation direction, said outlet openings of the chamber being positioned on an underpressure side of the pipes with respect to the rotation direction of the gas injection device.
  • 49. The agitator of claim 43 wherein the propeller is defined by a center plane and has a diameter, said gas injection device being defined by a center plane which is spaced from the center plane of the propeller by an axial distance which is about 25% to 75% of the diameter of the propeller.
  • 50. The agitator of claim 43 wherein the gas injection device is arranged on the pressure side of the propeller for injecting gas into the vessel.
  • 51. The agitator of claim 38 wherein the propeller defines a diameter, said gas-conducting device including a plurality of outlet openings in fluid communication with the outlet means, said outlet openings being located on a diameter which is about 35% to 75% of the diameter of the propeller.
  • 52. The agitator of claim 51 wherein the gas injection device rotates in a rotation direction, said outlet openings being positioned on an underpressure side of the gas-conducting device with respect to the rotation direction of the gas injection device.
  • 53. The agitator of claim 38, and further comprising a stationary distributor head fluidly connected with the interior space of the gas-conducting device for supply of gas from the gas source.
  • 54. An agitator for agitating liquids, with a gas being added to the liquid, in particular for suspending solids and dispersing gas in the liquid in flue gas desulfurizing plants, said agitator comprising:an agitator vessel having an interior; an agitator shaft extending into the interior of the agitator vessel to thereby define an axis; an agitating propeller mounted to the agitator shaft within the agitator vessel for axially moving a liquid in the agitator vessel in a conveying direction; and a gas injection device, rotating conjointly with the agitator shaft and positioned at an axial distance downstream of the agitating propeller in the conveying direction of the liquid, for injecting gas into the interior of the agitator vessel.
  • 55. The agitator of claim 54, wherein the gas injection device rotates in a rotation direction and has outlet openings positioned on an underpressure side with respect to the rotation direction of the gas injection device for gas so as to realize a pre-dispersing of the gas in concert with the propeller.
  • 56. The agitator of claim 54, wherein the gas injection device is arranged on the pressure side of the agitating propeller for injecting gas into the agitator vessel.
  • 57. The agitator of claim 54, and further comprising a gas source in communication with the gas injection device for supplying gas to the gas injection device.
Priority Claims (1)
Number Date Country Kind
299 09 312 U May 1999 DE
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