Patent ID: 12208379

POSITION NUMBERS

01. Mixing device.02. Inlet.03. Mixing section.04. Discharging section.05. Pipe segment.06. Flange.07. Support beam.08. Support grid.09. Divider plate.10. Pipe connection segment.

DESCRIPTION OF THE DRAWINGS

A number of embodiments of the invention will be explained in more detail in the following, with reference to the drawings.

The isometric view presented inFIG.1shows a top/side view of a part of the mixing device01comprised between catalytic beds in a multi-bed catalytic reactor (not shown). The mixing device has a circular shape to correspond the inner circular wall of the cylindrical reactor wherein the mixing device is to be installed. The support grid08which supports the above catalytic bed (not shown) is covering the upper part of the mixing device, only a central part of the support grid is removed inFIG.1, illustrating how the support grid is made of segments which can be removed to provide space for service. This is also the case for the underlying divider plate09. A part of the two support beams07can be seen.

More support grid segments have been removed inFIG.2which reveals more of the divider plate. Here it is more clearly seen how the divider plate fluidly seals the upper catalytic bed from the catalytic bed below the mixing device, forcing essentially all the process fluid to flow through the inlet02and further through the mixing section03before it is evenly distributed to the catalytic bed below the mixing device (it is to be understood that during installation the central hole will be covered by a segment of the divider plate). A small part of the mixing section can be seen, already showing how the mixing section is made from pipe segments05, which are mechanically connected by flanges06, providing a fluid tight connection of all the pipe segments.

InFIG.3, the mixing device has been stripped of all the divider plate and support grid-segments, reviling all the connected pipe segments as well as most of the support beams. It can be seen how this embodiment of the invention comprises two concentric circles of pipe segments which are connected by a spiral shaped pipe connection segment10. The outer circle is the mixing section, and the inner circle is the discharging section04. Again, imagining that the divider plate fluidly seals off the upper catalyst bed from the lower catalyst bed, the process fluid flow will come from the upper catalyst bed, in through the inlet, perform a circular motion in the mixing section, where the fluid which may comprise gas, liquid and vapour phase is mixed, then it flows on to the discharging section (the inner circle) through the pipe connection segment and is evenly distributed on to the lower catalyst bed. It can be seen from the drawing how the mixing and discharging-section is integrated into the support beams through apertures in the support beams, which minimizes the space taken from the catalytic reactor by the mixing device, while still providing good mixing and redistribution with a minimized pressure loss. This is also seen inFIG.4andFIG.5, where further the opening at the total inner circumference of the discharging section is visible, which provides the exit for the process fluid further to the below catalyst bed. This opening may comprise guide vanes (not shown) which enhances the even distribution of the fluid and also stabilizes the discharging section.

In the shown embodiment, the pipe segments are cut at an angle different from 90 degrees relative to the pipe segment axis. In this way the flanges which may have inwards protruding edges may enhance mixing of the fluid within the mixing section with a modest pressure drop. The pipe segment assembly and the angled ellipsoid shaped flanges are shown in more detail inFIG.6,FIG.7andFIG.8. It is to be understood that the flanges may have holes for mechanical connection and that gaskets may be provided between the flanges. In an embodiment, the flanges may protrude inwardly only at the outer circumference of the mixing section.

EXAMPLE

The new mechanical construction is based on bent tubes. The bent tubes are not adjacent to each other and to the support ring and thus they can have flanges at the extremities. Full flanges facilitate the connection between two tubes. The flanges can be opportunely shaped (ellipsoidal, and broad rimmed) to achieve process functionalities described later.

The tubes are supported through independent beams, which also support a plate at the top—which ensures that all gas and liquid are collected through the inlet of the mixing chamber. The top plate is flat (very simple construction). The beams rest on the support ring and they support the flat top and the tubes. The only significant welds of the construction are the connection between the flanges and the bent pipes. The full flanges have a smaller diameter than the tubes, and they can be shaped such to deliver an anti-segregation function. The beams are obtained by riveting together multiple thin metal plates. (The plates are so thin that the holes accommodating the tubes can be laser cut). The catalyst support and the mixer is integrated by this solution. The catalyst support beams are often very large and dimensioned for a very large total load. There may be very little or no additional extra load to take into consideration if the same beams shall support the mixer as well. The new beams have an upper part embedded in the grids, and giving a flat surface for catalyst loading, and a lower part supporting the mixer.

The quench section is ideally shorter than the known solutions, since it eliminates the empty space between catalyst support and mixer, and it offers flexibility as to the mixer geometry. Furthermore, it offers a flat catalyst support surface towards the ceramic balls/catalyst.

Effects and Advantages

1: Reliable and simpler installation2: Removal of all structural welds—Cheap manufacturing3: Space reduction and easier catalyst loading