SU887907A1 - Fluidised-bed furnace grill - Google Patents

Description

I

The invention relates to building materials, the metallurgical and chemical industries.

In the design of a multi-zone fluidized bed unit, one of the most important components is the intermediate grids. Domestic and foreign experience in operating multi-zone CS furnaces shows that the resistance of the gratings practically determines the duration of the furnace campaign. The grates of different zones of the furnace operate in different temperature and energy conditions, and their design places different demands.

Under the most severe conditions, the heating zone grille works, following the gas flow directly behind the burning zone. High temperature flue gas flows under the grate heating zone. In addition, the flue gas is contained in the gas stream from the burning zone. The heated dust particles accumulate in the holes of the bottom, which leads to an increase in the resistance of the lattice, and consequently, the load on it and the deterioration of its aerodynamic quality.

Particularly important for the construction of the intermediate lattice is its mechanical strength. The lattice experiences a two-sided load during operation, from below - equal to the loss of pressure (lattice resistance), and from above, equal pressure pulsations in the fluidized bed, as well as all parts of the bed or the entire bed in case of an emergency stove of the furnace. Making the grid load stable from above is quite simple -

10 creating arch support structures. It is more difficult to solve constructively the load perception from below — it can be compensated either by the weight of the grid, or by the coupling of individual elements of the grid with

15 using special structural devices.

An example of such a solution could be a lattice having horizontal upper and lower edges, made of refractory blocks. Each unit has a vertically arranged cylindrical opening for the passage of a liquefying agent. The structures are supported by the arches, with some 38 steps, made of the standard {surchich). The position of c is fixed by sliding bricks. The arches are supported by floating bricks laid in the nests of the sub-beam. An arched standard brick is laid on the arches so that the surface of the masonry is horizontal, and the bottom refractory blocks are laid on top. In order to perceive the uncompensated weight of the lattice, the blocks have lock joints of the dovetail type I. A significant disadvantage of this design is the low durability of the supporting arches. At. by alternating heat loads, they lose stability in the horizontal plane, which leads to the destruction of the arches and the loss of support by the grid. In addition to this weighed. The flow of the stream, the passage into the grate opening between the arches, wears the latter, also violating their integrity. The need to create a horizontal surface of the arches due to the laying of hewn brick makes the construction of the lattice time consuming, requires the use of specialized and highly skilled labor. Closest to the proposed technical entity is a perforated bottom of the furnace of the knitted layer, filled with refractory blocks that form the surface of the spherical segment with their lower edges and the horizontal surface with the upper edges. Each block has a cylindrical channel directed along the normal to the spherical surface 2. Adjacent to each other, the bottom (grating) blocks are less susceptible to abrasive wear than the lattice arches spaced from each other, and the dome surface gives it stability when perceived loads from above. However, this lattice has a number of significant drawbacks. The creation of the lower domed lattice configuration leads to the need to co-structure the refractory blocks of complex shape, which were not prepared using the press method. For the same reason, there is a need to design a large number of sizes of shaped refractory blocks. The molded metal inserts with which the lattice blocks are equipped are located on a part of the height of the block, the rest of the opening is in the body of the refractory block with a metal insert or at an angle to it; This obstruction causes increased abrasive wear of the holes in the blocks. The different length and configuration of the holes cause different resistances of different zones of the mesh, which can cause a redistribution of flow along the cross section of the apparatus. The aim of the invention is to simplify the design by using standardized shaped blocks. This goal is achieved by the fact that the fluidized bed furnace grating, containing shaped refractory pads with holes, in which wafers for passing a fluidizing agent are installed, is made of shaped refractory blocks and standard refractories arranged in parallel rows adjoining each other and forming upper horizontal and lower arched surface. FIG. 1 shows the proposed lattice, vertical section; in fig. 2 - the same, top view. PejueTKa is a combination of a series of parallel arches, each of which is assembled from shaped refractory blocks and standard refractories. The bridge contains five bricks 1 that support it and are placed in the sockets of the beam 2. The standard brick 3 transfers the grating support force to the fifth bricks 1. The shaped support blocks 4-8 have an upper horizontal edge, the lower edge of the block is part arched surface. The unit has a cylindrical hole with a vertical axis into which an insert 9 is installed for the passage of a fluidizing agent. The side faces of each block lie in the plane passing through the top edge of the block (point A in the plane of the vertical section) and the locus of the points of application of the radii to the lower arched surface. Such a grate design of the fluidized bed furnace has the following advantages. The number of refractory block sizes is significantly reduced. The construction of the block allows for its manufacture by pressing. The equipment of the blocks with inserts of the same length creates conditions for uniform distribution of the flow over the cross section of the apparatus, and their arrangement along the entire length of the channel 6 of the refractory block removes the question of the abrasive wear of refractories. The construction of each arch as a combination of shaped and standard refractories, and the entire lattice as a parallel set of arches makes the proposed design universal for the construction of intermediate grates in furnaces of different diameters and different cross sections.

Claims (1)

Claim A fluidized bed furnace grate comprising shaped refractory blocks with openings in which inserts for fluidizing agent passage are installed, characterized in that, in order to simplify the design by using standardized shaped 887907 4 blocks, it is made of shaped refractory blocks and standard refractories installed in parallel rows adjacent to each other and forming the upper horizontal and lower arched surfaces. I am ¹