System for dense loading of catalyst into bayonet tubes for a steam reforming exchanger-reactor using removable helical elements

Patent metadata

Field	Value
Publication number	US-9486764-B2
Application number	US-201314436731-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

The present invention describes a device and a method for dense and homogeneous loading of catalyst into the annular space of bayonet tubes employed in a steam reforming reactor, said device being constituted by a series of removable helical elements.

First claim

The invention claimed is:

1. A device for densely filling catalyst specially adapted to a steam reforming exchanger-reactor containing a plurality of bayonet tubes enclosed in a shell, the catalyst being constituted by particles occupying at least a portion of the annular space ( 4 ) included between an internal tube ( 5 ) and an external tube ( 6 ), the assembly of said two tubes constituting a bayonet tube, the width of said annular space being in the range 30 mm to 80 mm, and its height being in the range 10 to 20 meters, the particles of catalyst being in the form of cylinders with an approximate height of 10 mm to 20 mm and an approximate diameter of 10 mm to 20 mm, the device containing:
a series of shaftless helical elements ( 7 ) distributed vertically along the length of the annular space ( 4 ) in a regular manner with a length in the range 1 to 1.5 pitches of the helix, said elements being separated by a vertical distance in the range 50 cm to 150 cm;
said helical elements ( 7 ) being connected together via a chain ( 8 ) which is wound around a spooler ( 10 ) located outside the tube to be filled, and the particles of catalyst being contained in:
a central feed hopper ( 1 ) for delivering the particles onto a conveyor belt ( 2 ) supplying the annular space ( 4 ) by:
a funnel ( 3 ) via which the particles flow into the interior of the annular space ( 4 ).

2. The filling device according to claim 1 , in which each helical element has a length in the range 1 pitch of the helix to 1.3 pitches of the helix.

3. The filling device according to claim 1 , in which each helical element ( 7 ) is in the form of a plane inclined downwardly at an angle alpha with respect to the vertical in the range 30° to 50°.

4. The filling device according to claim 1 , in which two successive helical elements ( 7 ) have reversed directions of rotation, one being “left handed” and the other being “right handed”.

5. The filling device according to claim 1 in which, when the diameter of the wall of the annular space ( 4 ) varies because of the internal diameter of portions of the external tube ( 6 ), the system of helical elements ( 7 ) is provided, at its ends nearest to the wall of the annular space ( 4 ), with lips formed from rubber which can be used to adjust the width of the inclined plane in a manner such as to obtain a contact with the internal wall of the annular space ( 4 ).

6. The filling device according to claim 5 , in which the helical element which is nearest to the bed of particles is equipped with weights which can be used to overcome the friction of the rubber lips on the wall of the external tube ( 6 ).

7. A method for loading catalyst using the device according to claim 1 , comprising the following series of steps:
initially winding the loading system into the external spooler ( 10 ), the feed hopper ( 1 ) being filled with solid;
the loading system is then gradually introduced into the annular zone ( 4 ) via its upper portion until the first helical element ( 7 ) reaches a distance with respect to the bottom of the tube in the range 50 cm to 100 cm;
the conveyor belt ( 2 ) is started up so as to provide a flow rate of solid in the range 250 kg/h to 500 kg/h, the solid particles being introduced into the annular zone ( 4 ) via the funnel ( 3 );
as and when the annular zone ( 4 ) is filled, the loading system is raised in the annular zone ( 4 ) with the aid of the external spooler ( 10 ) in a manner such as to keep a constant distance between the first helical element and the surface of the bed which is gradually being constituted, said distance being in the range 50 cm to 100 cm;
the system is wound up at a speed equivalent to the speed of loading of the tube, in the range 0.2 in/min to 0.4 m/min;
once the tube has been loaded and the loading system wound up, the system is displaced in order to load the next tube.

8. A device according to claim 1 for densely filling catalyst specially adapted to a steam reforming exchanger-reactor consisting of a plurality of bayonet tubes enclosed in a shell, the catalyst being constituted by particles occupying at least a portion of the annular space ( 4 ) included between an internal tube ( 5 ) and an external tube ( 6 ), the assembly of said two tubes constituting a bayonet tube, the width of said annular space being in the range 30 mm to 80 mm, and its height being in the range 10 to 20 meters, the particles of catalyst being in the form of cylinders with an approximate height of 10 mm to 20 mm and an approximate diameter of 10 mm to 20 mm, the device consisting of:
a series of shaftless helical elements ( 7 ) distributed vertically along the length of the annular space ( 4 ) in a regular manner with a length in the range 1 to 1.5 pitches of the helix, said elements being separated by a vertical distance in the range 50 cm to 150 cm;
said helical elements ( 7 ) being connected together via a chain ( 8 ) which is wound around a spooler ( 10 ) located outside the tube to be filled, and the particles of catalyst being contained in:
a central feed hopper ( 1 ) for delivering the particles onto a conveyor belt ( 2 ) supplying the annular space ( 4 ) by:
a funnel ( 3 ) via which the particles flow into the interior of the annular space ( 4 ).

9. The filling device according to claim 8 , in which each helical element has a length in the range 1 pitch of the helix to 1.3 pitches of the helix.

10. The filling device according to claim 8 , in which each helical element ( 7 ) is in the form of a plane inclined downwardly at an angle alpha with respect to the vertical in the range 30° to 50°.

11. The filling device according to claim 8 , in which two successive helical elements ( 7 ) have reversed directions of rotation, one being “left handed” and the other being “right handed”.

12. The filling device according to claim 8 in which, when the diameter of the wall of the annular space ( 4 ) varies because of the internal diameter of portions of the external tube ( 6 ), the system of helical elements ( 7 ) is provided, at its ends nearest to the wall of the annular space ( 4 ), with lips formed from rubber which can be used to adjust the width of the inclined plane in a manner such as to obtain a contact with the internal wall of the annular space ( 4 ).

13. The filling device according to claim 12 , in which the helical element which is nearest to the bed of particles is equipped with weights which can be used to overcome the friction of the rubber lips on the wall of the external tube ( 6 ).

14. A method for loading catalyst using the device according to claim 8 , comprising the following series of steps:
initially winding the loading system into the external spooler ( 10 ), the feed hopper ( 1 ) being filled with solid;
the loading system is then gradually introduced into the annular zone ( 4 ) via its upper portion until the first helical element ( 7 ) reaches a distance with respect to the bottom of the tube in the range 50 cm to 100 cm;
the conveyor belt ( 2 ) is started up so as to provide a flow rate of solid in the range 250 kg/h to 500 kg/h, the solid particles being introduced into the annular zone ( 4 ) via the funnel ( 3 );
as and when the annular zone ( 4 ) is filled, the loading system is raised in the annular zone ( 4 ) with the aid of the external spooler ( 10 ) in a manner such as to keep a constant distance between the first helical element and the surface of the bed which is gradually being constituted, said distance being in the range 50 cm to 100 cm;
the system is wound up at a speed equivalent to the speed of loading of the tube, in the range 0.2 m/min to 0.4 m/min;
once the

Assignees

• Ifp Energies Now

Inventors

• Sanz Elena
• Beaumont Robert
• Bergeot Ghislain
• Boyer Christophe

Classifications

• B01J8/003 Primary

  in a downward flow · CPC title

• B01J8/002

  with a moving instrument · CPC title

• B01J2208/00752

  Feeding · CPC title

• B01J8/06

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