Coal ash agglomeration device

• US 3,935,825 A
• Filed: 02/24/1975
• Issued: 02/03/1976
• Est. Priority Date: 02/24/1975
• Status: Expired due to Term

• Current Assignee: Gas Technology Institute
• Original Assignee: Institute Of Gas Technology (GTI Energy)
• Inventors: Patel, Jitendra G., Matthews, Charles W.
• Primary Examiner(s): Sprague, Kenneth W.
• Application Number:
  US05/552,157
• Time in Patent Office: 344 Days
• Field of Search: 48/63, 48/64, 48/76, 48/202, 48/206, 201/9, 201/14, 201/15, 201/28, 201/29, 201/31, 423/659, 110/165 R, 110/165 A, 110/28 J
• US Class Current: 110/165.00R
• CPC Class Codes: B01J 8/003 in a downward flow
• CPC Class Codes: C10J 2300/093 Coal
• CPC Class Codes: C10J 2300/0956 Air or oxygen enriched air
• CPC Class Codes: C10J 2300/0976 as steam
• CPC Class Codes: C10J 3/36 Fixed grates
• CPC Class Codes: C10J 3/523 for gasifiers with stationary fluidised bed
• CPC Class Codes: C10J 3/74 Construction of shells or jackets

Abstract

An improved apparatus for withdrawing agglomerated solids from a fluidizing chamber housing a main, fluidized bed of finely divided solids which comprises at least one withdrawal chamber having a width less than the fluidizing chamber and positioned below the fluidized bed. This withdrawal chamber has sufficient dimensions (width (or diameter when cylindrical) and depth) to contain a second fluidized or semi-fixed bed within said chamber when a high velocity gas stream is introduced into the bottom portion of the withdrawal chamber. This high velocity gas stream forms an inverted cone in the withdrawal chamber, wherein the walls of the cone are defined by the fluidized or semi-fixed bed within the withdrawal chamber. The velocity of the gas stream is adjusted to selectively remove high density agglomerates downward from the main fluidized bed without removing the fluidized solids in admixture therewith. This apparatus is particularly suited for withdrawing agglomerated ash particles from the fluidized bed of a coal gasification reactor.

Claims

1. In an apparatus for contacting a mass of fluidized solids with a gaseous medium and withdrawing agglomerated solids from the mass of fluidized solids wherein the apparatus includes a fluidizing chamber, a grate positioned near the bottom of the fluidizing chamber to support said fluid bed and means for passing a gaseous medium through said grate to assist in maintaining the solids in a fluidized state, the improved apparatus for withdrawing agglomerated solids from said mass of fluidized solids which comprises at least one withdrawal chamber having a width less than the width of the fluidizing chamber, positioned below said fluid bed and open at the top to communicate with the fluidizing chamber and, means for introducing a high velocity fluidizing gaseous medium to the bottom portion of said withdrawal chamber, said withdrawal chamber having dimensions sufficient to contain a semi-fixed bed within said chamber, said high velocity gaseous means positioned in said withdrawal chamber to provide a high velocity inverted conical shaped gaseous flow pattern through the semi-fixed bed, the walls of said pattern provided by said semi-fixed bed.

2. An apparatus as in claim 1 which includes a cylindrical baffle positioned within said withdrawal chamber to prevent sloughing of the surface of the semi-fixed bed with said chamber, said baffle positioned above the introduction point of the high velocity gaseous medium, and having walls parallel to the flow of gas through said cone.

3. An apparatus as in claim 1 which includes means for introducing a low velocity gaseous stream to the bottom of said chamber at a point laterally removed from the point of introduction of the high velocity gaseous stream to help maintain the bed in a semi-fixed condition within the withdrawal chamber.

4. An apparatus as in claim 1 wherein the discharge point of said high velocity gaseous introduction means is positioned above the bottom of the withdrawal chamber.

5. An apparatus as in claim 1 wherein said withdrawal chamber comprises a cylindrical chamber having a cylindrical baffle concentrically positioned therein above the introduction point of the high velocity gaseous medium, said gaseous medium discharged in the center of said chamber.

6. An apparatus as in claim 5 wherein the discharge point of said high velocity gaseous introduction means is positioned above the bottom of the withdrawal chamber and said apparatus includes means for introducing a low velocity gaseous stream to the bottom of said chamber at a point laterally removed from the point of introduction of the high velocity gaseous stream to help maintain the bed in semi-fixed condition within the withdrawal chamber.

7. An apparatus as in claim 1 which includes an adjustable sleeve positioned within said chamber and means for adjusting the height of said sleeve thereby adjusting the height of said chamber.

8. An apparatus as in claim 1 which includes means for quickly arresting the flow of gas to said high velocity gaseous introduction means.

10. A process in claim 7 which includes passing a second low velocity gas stream into said chamber laterally from said first high velocity stream to maintain the solids within said chamber in a semi-fixed state.

11. A process according to claim 1 which includes adjusting the height of the withdrawal chamber by moving a adjustable sleeve positioned within said chamber.

9. A process for withdrawing agglomerated solids from the bottom of a fluidized bed of finely divided solids which comprises:

introducing a first high velocity gas stream upwardly into a vessel containing a bed of fluidizable solids through at least one withdrawal chamber, said withdrawal chamber comprising a chamber open at the top and having positioned in the bottom portion thereof an opening to receive said high velocity gas stream said chamber having dimensions sufficient to contain a semi-fixed bed within said chamber;

permitting finely divided solids to flow from the fluid bed into said chamber around the perimeter thereof;

maintaining the finely divided solids as a semi-fixed bed in said chamber, and;

adjusting the velocity of the high velocity gas stream to form an inverted cone within said chamber, the walls of said cone being the walls of the semi-fixed bed, said velocity being adjusted to permit the selective removal of agglomerated solids from said bed without removal of finely divided solids therefrom.