Technical comparison
Comparative example
The drawings show a Si-Al grid brick at the bottom of the currently used, hexagonal type regenerator with an interaxial distance of the vertical channels of 45 mm – and therefore the side of the regular hexagon of the network of 90 mm – and the inner diameter of the vertical channels varies in height between 30 mm at the bottom and 27 mm at the top (on average 28.5). In operation, the heat transfer area per cubic meter of structure is approximately 51 sq m/m3, regardless of the height of the brick in the grid. On the right side we have a corresponding similarly bred brick, made according to the patent. The height of the two bricks in the grid is identical and set at 60 mm to illustrate the importance of this value in the case of the new grid brick (it is inversely proportional to the number of possible horizontal channels per unit volume of the structure).
The volume and surface data are presented in the comparative table and are based on the figures provided by the computerized “3D” drawing of the drawings. It should be noted that the manufacturing values differ from those in operation due to the expansion of the refractory material, so that the exact figures belong to the manufacturing drawings.
Top view of classic brick
Top view of the new brick
Bottom view of classic brick
Bottom view of new brick
Comparative table - example of a checkered brick according to the patent
– Dimensions in manufacture according to drawings –
Note:
Along with the drawings of plaid bricks, views of them and of the structure in the 3D version, made in the new technical solution, are also presented.
In order to minimize possible pressure increases in the vertical circulation of gases, a very small change in the porosity of the new structure was used compared to the current one in this direction (below 5%). The joints of the new plaid brick in the structure are of the “1 over 4 and 4 over 1” type and are oriented radially towards the center of the plaid bricks so as not to generate problems due to expansion.
Due to the surface differences of the horizontal sections of the vertical channels with which the internal horizontal channels join, the gas flow through the horizontal channels will be higher than that of the main vertical circulation, and due to the small sections of these horizontal channels, the flow gas will have a laminar and not turbulent as in the case of vertical circulation.
When mounting bricks in the grid, most of the horizontal channels of the upper face overlap with the horizontal channels of the lower face in the next row, which makes the support surface maximum. In operation, due to expansion, this overlap decreases. The table shows the extreme (hypothetical) value in which the gap is total. This situation is to the advantage of the heat transfer surface, which will in reality, during operation, have a higher value than that presented in the table, corresponding to the hypothetical situation.
It is observed that the manufacturing problems of the new type of checkered bricks compared to the existing ones are not important, because the making of these horizontal channels on the surfaces of the square bricks is easily obtained by profiling some triangular ribs on the pressing plates of the molds. It is understandable that the sharp edges will need to be replaced with curved joints and appropriate rays.
Checkered brick assembly - new structure
Another example
Comparative table – example of a checkered brick according to the patent
– Dimensions in manufacture according to drawings –
Horizontal circulation and turbulence
Horizontal and vertical circulation
Note:
The example presents a type of checkered silica brick in the upper part of the regenerator, where the interaxial distance between the vertical channels is 55 mm, the height of the checkered brick is 150 mm, and their average diameter is 32 mm. The horizontal channels in the new pattern are present only on the lower face of the plaid brick. Dimensions and calculations were performed on the plaid brick from the manufacturing stage.
Two schematic figures of the appearance of horizontal vortices that the horizontal channels cause in the vertical flow of the main vertical channels are also presented, as well as the alternate direction in which the gases enter and exit horizontally from one row to another in the structure of the vertical channels. This happens because these channels are made up of alternately different size hollows.
Vertical section of old classic plaid brick
new plaid brick
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