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Process for operating a magnetically stabilized fluidized bed

  • US RE31,439 E
  • Filed: 09/24/1980
  • Issued: 11/15/1983
  • Est. Priority Date: 10/11/1974
  • Status: Expired due to Term
First Claim
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1. [.26. The process of claim 25 wherein the uniformity of said applied magnetic field is such that the ratio of the local intensity of the applied magnetic field to the mean field varies by no more than 25% over the region of a portion of the fluidized bed containing the particulate magnetizable, fluidizable material..]. .[.27. The process of claim 25 wherein the uniformity of said applied magnetic field is such that the ratio of the local intensity of the applied magnetic field to the mean field varies by no more than 10% over the region of a portion of the fluidized bed containing the particulate magnetizable, fluidizable material..]. .[.28. The process of claim 25 wherein the uniformity of said applied magnetic field is such that the ratio of the local intensity of the applied magnetic field to the mean field varies by no more than 5% over the region of a portion of the fluidized bed containing the particulate magnetizable, fluidizable material..]. .[.29. A fluidized bed process, which comprises stably fluidizing at least a portion of a bed comprised of solid particulate magnetizable, fluidizable composite particles which contain 2-40 volume percent of ferro- or ferrimagnetic material located within an external force field containing said composite materials to a nontime varying and substantially uniform applied magnetic field having a substantial component along the direction of the external force field such that said composite particles have a component of magnetization M along the direction of the external force field of at least 100 gauss by passing a gas opposing said external force field at a superficial fluid velocity ranging between:

  • (a) more than the normal minimum fluidization superficial fluid velocity required to fluidize said bed in the absence of said applied magnetic field; and

    ,(b) less than the superficial fluid velocity required to cause time-varying fluctuations of pressure difference through said stably fluidized bed portion over a 0.1 to 1 second interval during continuous fluidization in the presence of said applied magnetic field..]. .[.30. The process of claim 29 wherein said fluidized bed is subjected to an applied magnetic field ranging between 150 to 400 oersteds oriented axially to the flow of gas in the stably fluidized bed zone..]. .[.31. The process of claim 29 wherein said fluidizing gas has a superficial velocity in the range of 2 to 10 times the normal minimum superficial gas velocity required to fluidize the bed in the absence of an applied magnetic field..]. .[.32. The process of 29 wherein the magnetizable, fluidizable composite particles contain catalytic nonmagnetic material..]. .[.33. The process of claim 29 wherein the magnetizable, fluidizable composite particles contain a zeolitic crystalline aluminosilicate and a ferromagnetic material..]. .[.34. The process of claim 29 wherein the magnetizable, fluidizable composite particles contain 5 to 20 volume percent ferro- or ferrimagnetic material and the balance is nonmagnetic material..]. .Iadd. 35. A process for controllably transporting a flowable bed containing magnetizable particles within a vessel, said bed being expanded and levitated within said vessel by a fluid stream, wherein the superficial fluid velocity of said fluid stream ranges between;

    (1) more than the normal fluidization superficial fluid velocity required to expand and levitate said bed in the absence of said applied magnetic field; and

    (2) less than the superficial fluid velocity required to cause time-varying fluctuations of pressure difference through said expanded and levitated bed over a finite period of time during continuous operation in the presence of said applied magnetic field, said process comprising the steps;

    (a) subjecting at least a portion of said bed to an applied magnetic field having a substantial component along the direction of a force field external to said bed; and

    (b) controllably transporting said bed within said vessel in response to a pressure differential in said bed. .Iaddend. .Iadd. 36. The process of claim 35 wherein said external force field is gravity. .Iaddend..Iadd. 37. The process of claim 35 wherein said fluid is gaseous. .Iaddend..Iadd. 38. The process of claim 35 wherein said bed additionally contains nonmagnetizable particles. .Iaddend..Iadd. 39. The process of claim 35 wherein said magnetizable particles are comprised of composite particles which include magnetizable and nonmagnetizable material. .Iaddend..Iadd. 40. The process of claim 39 wherein said composite particles include a zeolitic material. .Iaddend..Iadd. 41. The process of claims 35, 36, 37, 38, 39 or 40 wherein said applied magnetic field is nontime-varying and substantially uniform. .Iaddend..Iadd. 42. The process of claims 35, 36, 37, 38, 39 or 40 wherein said applied magnetic field is time-varying and substantially uniform and wherein said magnetizable particles have a zero or relatively low coercivity. .Iaddend..Iadd. 43. The process of claim 35 wherein the flow of fluid is not substantially more than about 98% of the superficial fluid velocity required to cause a 0.1% ratio of root-mean square fluctuation of pressure difference to mean-pressure difference through the expanded bed in the presence of said applied magnetic field. .Iaddend..Iadd. 44. The process of claim 35 wherein the uniformity of said applied magnetic field is such that the ratio of local intensity of the applied magnetic field to the mean field varies by not more than 25% over the region of the bed containing the magnetizable particles. .Iaddend..Iadd. 45. The process of the claim 35 wherein the uniformity of said applied magnetic field is such that the ratio of the local intensity of the applied magnetic field to the mean field varies by no more than 10% over the region of the bed containing magnetizable particles. .Iaddend. .Iadd. 46. The process of claim 35 wherein the uniformity of said applied magnetic field is such that the ratio of the local intensity of the applied magnetic field to the mean field varies by no more than 5% over the region of the bed containing magnetizable particles. .Iaddend..Iadd. 47. The process of claim 35 wherein said bed medium is transported in a plug-flow manner. .Iaddend..Iadd. 48. The process of claim 35 wherein said bed medium is transported from one vessel to another vessel. .Iaddend..Iadd. 49. A process for controllably transporting a flowable bed containing magnetizable particles within a vessel, said bed being expanded and levitated within said vessel by a fluid stream, said process comprising the steps;

    (a) subjecting at least a portion of said bed to an applied magnetic field having a substantial component along the direction of gravity of at least 10 gauss within said bed; and

    (b) controllably transporting said bed in response to a pressure differential in said bed within said vessel, wherein the superficial fluid velocity of said fluid stream ranges between;

    (1) at least about 10% greater than the normal fluidization superficial fluid velocity required to expand and levitate said bed in the absence of said applied magnetic field; and

    (2) less than the superficial fluid velocity required to cause time-varying fluctuations of pressure difference through said expanded and levitated bed over a finite period of time during continuous operation in the

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