Pneumatic system for densely loading catalyst into bayonet tubes for a steam reforming reactor-exchanger with a detachable feed tube for gas

Patent metadata

Field	Value
Publication number	US-9486766-B2
Application number	US-201314435492-A
Country	US
Kind code	B2
Filing date	Sep 24, 2013
Priority date	Oct 17, 2012
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

A device and a method are disclosed for densely and homogeneously loading catalyst into the annular space of bayonet tubes utilized in a steam reforming reactor. The device is of pneumatic type and uses a detachable feed tube for introducing gas into the annular space.

First claim

The invention claimed is:

1. A device for densely filling catalyst particles into a steam reforming reactor-exchanger, to form a catalyst bed composed of catalyst particles therein, said steam reforming reactor-exchanger containing a plurality of bayonet tubes enclosed in a shell wherein each bayonet tubes having an inner tube ( 5 ) and an outer tube ( 6 ) with an annular space between said inner tube ( 5 ) and said outer tube ( 6 ), said catalyst bed occupying at least in part the annular space ( 4 ) between said inner tube ( 5 ) and said outer tube ( 6 ), wherein the width of said annular space ( 4 ) is between 40 mm and 80 mm, and the height of said annular space ( 4 ) is between 10 and 20 meters, said catalyst particles being in the shape of cylinders with a height between 10 mm and 20 mm, and a diameter between 5 mm and 20 mm, wherein said device comprises:
a detachable flexible tube ( 7 ), having a first end, adapted to enter inside said annular zone ( 4 ) of one of said bayonet tubes so that said first end can be maintained at a distance between 150 mm and 200 mm from the surface of said catalyst bed, said flexible tube capable of introducing between 70% and 85% of a gas flow introduced into said annular space during the filling thereof with said catalyst particles, the remaining portion of said gas flow being introduced into the annular space by said inner tube ( 5 ), the diameter of said detachable flexible tube ( 7 ) being between 0.5 and 0.9 times the width of said annular space ( 4 ) or between 0.5 and 0.9 times of the smallest width of said annular space ( 4 ) in the case where said outer tube ( 6 ) has a changing diameter,
a winder ( 10 ) located outside of the bayonet tube to be filled for winding and unwinding said detachable flexible tube ( 7 ),
a central hopper ( 1 ) containing catalyst particles for delivering catalyst particles onto a conveyor belt or onto a shaking conveyor ( 2 ) for feeding catalyst particles into said annular space ( 4 ) via a funnel ( 3 ), through which the catalyst particles flow into said annular space ( 4 ).

2. The device according to claim 1 , wherein said detachable tube ( 7 ) is equipped at said first end end with an end piece which is closed at the end thereof and provided with a series of lateral holes arranged in one or more rows for the discharge of said gas flow, the diameter of said lateral holes being between 10 and 15 mm and the spacing between rows of said lateral holes being between 15 and 30 mm, each row having from 3 to 8 holes.

3. A method for loading catalyst into a bayonet tube using the device according to claim 1 , said method comprising:
winding said detachable flexible tube ( 7 ) around said winder ( 10 ), and filing said central hopper ( 1 ) with catalyst particles,
introducing said detachable flexible tube ( 7 ) progressively into said annular zone ( 4 ) until said first end is located at a distance between 50 cm and 100 cm with respect to the bottom of said bayonet tube,
introducing a constant gas flow into said inner tube ( 5 ) of said bayonet tube at a rate corresponding to a velocity in said annular space between 0.1 m/s and the minimum fluidizing velocity of the catalyst particles, and introducing another gas flow into said detachable flexible tube ( 7 ), wherein the sum of the flow rates of said gas flow and said another gas flow corresponds to to a velocity in said annular space between 8 m/s and 14 m/s, which is still less than the falling velocity of the catalyst particles that will cause the catalyst particles to break,
starting said conveyor belt or shaking conveyor ( 2 ) to supply a flow rate of between 250 kg/h and 500 kg/h of said catalyst particles into said annular zone ( 4 ) via said funnel ( 3 ),
winding up said detachable flexible tube ( 7 ) using said winder ( 10 ) as said annular zone ( 4 ) fills up with catalyst particles, in such a way that a constant distance is maintained with respect to the surface of the catalyst bed which is building up progressively, said distance being between 50 cm and 100 cm,
wherein the winding up of said detachable flexible tube ( 7 ) is conducted at a speed which is equivalent to a loading speed of catalyst particles into said bayonet tube between 0.2 m/min and 0.4 m/min, and
once said bayonet tube is loaded with catalyst particles, winding up said detachable flexible tube ( 7 ) unto said winder ( 10 ) and moving said detachable flexible tube ( 7 ) to the next bayonet tube to be loaded.

4. The method according to claim 3 , wherein the gas used in said gas flows is air or nitrogen.

5. The method according to claim 3 , wherein said detachable tube ( 7 ) is equipped at said first end with an end piece which is closed at the end thereof and provided with a series of lateral holes arranged in one or more rows for the discharge of said gas flow, the diameter of said lateral holes being between 10 and 15 mm and the spacing between rows of said lateral holes being between 15 and 30 mm, each row having from 3 to 8 holes.

6. The method according to claim 3 , wherein gas flow rates into said annular space are sufficient for the falling velocity of the catalyst particles in said annular space is between 2 m/s and 4 m/s less than the terminal velocity of fall for the catalyst particles.

7. The method according to claim 3 , wherein the falling velocity of the catalyst particles in said annular space is less than 3 m/s.

8. The method according to claim 3 , wherein the falling velocity of the catalyst particles in said annular space is less than 2 m/s.

9. The method according to claim 3 , wherein the sum of the flow rates of said gas flow and said another gas flow corresponds to a velocity in said annular space between 11 m/s and 13 m/s.

Assignees

• Ifp Energies Now

Inventors

• Sanz Elena
• Beaumont Robert
• Boyer Christophe
• Gonnet Daniel

Classifications

• B01J8/003

  in a downward flow · CPC title

• B01J2208/00752

  Feeding · CPC title

• B01J8/002

  with a moving instrument · CPC title

• B01J8/06 Primary

  in tube reactors; the solid particles being arranged in tubes · CPC title

• B01J8/0025

  by an ascending fluid · CPC title