DE974769C - Grate for fluidized bed reaction rooms - Google Patents

Description

ISSUED APRIL 20, 1961

B 35716 IVa / 12 g

Ludwigshafen / Rhine

have been named as inventors

For the treatment of solids with gases or vapors in fluidized beds are used as Base for the solids gas-permeable plates, perforated plates or consisting of individual rods Grates are used through which gases to be introduced into the fluidized bed are passed.

Gas-permeable plates have the advantage that, due to their pores, practically no solids in the air chamber located under the fluidized bed can get into it, but they have the disadvantage that when passing gases in the desired speed ranges high pressure losses develop.

In order to prevent solid material from falling through through perforated plates, it was proposed that to provide the perforated plates with ball locks or cover hoods. With ball locks however, solid falling through cannot be prevented with certainty. With perforated Plates with hoods on the other hand will not be even gas distribution over the whole Cross-section of the reaction space achieved because the hoods have a relatively large Have spacing of the individual gas passage openings from one another.

It is also already known to use the gaps between neighboring U-irons of a grate to cover roof-shaped angle iron. With such an arrangement, the U-irons can only be used with Lower temperatures can be used, while rustproof grates are used for higher temperatures Steel or ceramic components

109 55Φ / 3

are required. The roof structures are also discarded in a short time, as the rust from The air flow passing below does not have a sufficient cooling effect on them. Likewise enable the well-known grids consisting of simple T-beams only provide insufficient cooling, because the flow velocity of the air between the vertical parts of the T-beams is increasing is small to dissipate enough heat.

ίο A flat or moving grate is also known Boiler furnace, which consists of grate bars arranged in two levels, each grate bar has a structure that extends beyond the long sides and the structure of one in the upper level lying grate bar with the top of the adjacent bar lying in the lower level one upward gap forms, while the gaps between the foot of the upper grate bar and the respectively adjacent lower grate bar according to the usual for a plate grate Bar width are many times wider.

In contrast to this rust, which is always covered by a layer of ash and coal against the immediate one The effect of the furnace temperature is protected and its construction is based on it is that ashes can fall through the spaces between the individual rods, for what purpose the length of the spaces is kept as short as possible, must be with a Fluidized bed grate prevents solid particles from falling through the grate and a rapid dissipation of heat from the grate can be guaranteed, since in a fluidized bed furnace the Rust without any protection from the temperature in the fluidized bed, which is almost the same in all places is exposed.

According to another known proposal, hollow grate bars should go through for a furnace grate which the air to be supplied to the fuel is guided and preheated) with these rods covering T-shaped massive grate bars alternate and the distances between each The sticks should be large enough not to hinder the ash diarrhea. To avoid burns the grate bars or their warping due to overheating, it is also known, the grate bars in a boiler with a stationary fuel layer through cooling tubes built into the rods protection.

In contrast, it has been found that the fall through of solids is completely prevented and even gas admission over the entire cross-section of a fluidized bed space this is guaranteed if one is made of a planar structure made up of full grate bars arranged in parallel Grate used, of which every second grate bar consists of a lower one, in height versus width preferably formed part and a roof-shaped structure protruding beyond the grate level with a cross section extending beyond the longitudinal sides of the central part, according to the invention the grate bar, which is provided with a roof-shaped structure, is designed as a narrow gap Gas outlet openings between the lower part of this grate bar and the neighboring ones, uncovered bars covered and the underside of the structure and those covered by it Surfaces of the adjacent grate bars have a downward slope. Appropriate one chooses the inclination of the roof so that it corresponds to the angle of repose to be treated in the fluidized bed Corresponds to solid particles, causing deposits of solid particles on the roof-shaped Build-up of the grate bars can be prevented. In order to avoid solid particles in the Space between the covered bars clamped to the underside of the canopies, you can increase the distance between the undersides of two adjacent roofs a little as corresponds to the largest grain diameter of the solid to be swirled over this grate.

Due to the small distance in which the individual grate designed according to the invention Gas outlet slots are arranged next to one another, which is caused by the cross-sectional constriction Flow energy of the gas flow due to the passage through the slots at the exit of the Gas from the slots is largely destroyed by being deflected by the canopies individual gas streams collide directly. This leaves only the low flow energy, that of the gas velocity, on the diameter of the respective fluidized bed space related, corresponds, and it is the lowest possible abrasion of the solid particles in the fluidized bed guaranteed. This protection of the solid material during its treatment is for friable raw materials no less important than for soft and occurring during treatment Intermediate products at risk of abrasion and the end products obtained during treatment.

On the other hand, the arrangement according to the invention provides a sufficient upflow velocity a predetermined amount of gas is achieved with regard to the respective conversion to be carried out, which allows solid matter to fall through the grate gaps despite the fact that it promotes such a fall through Excludes pulsations in the fluidized bed, and adequate cooling of the grate guaranteed.

Claims (2)

PATENT CLAIMS: i. Flat grate for fluidized bed reaction rooms made of full grate bars arranged in parallel, each of which is formed from a lower one, preferably formed in height over width Part and from a roof-shaped structure with an over the gas passage opening serving gap between the lower part of a grate bar and the lower part of the it is adjacent grate bar extending cross-section, with every second grate bar compared to the grate bars adjacent to it by the width of the gas passage gap between the underside of its roof-shaped Structure and the top of the adjacent grate bar is increased, characterized in that the grate bar located between two elevated grate bars does not carry a roof-shaped structure and is separated in its vertical direction from the adjacent bars by parallel narrow gaps and that the underside of the roof-shaped structures adjacent bars and the covered surface of the grate bar in between have a downward slope. 2. Grate according to claim i, characterized in that the roof-shaped structure of the grate bar has a slope which corresponds to the angle of repose of the solid particles to be treated. Contemplated pamphlets; German Patent Nos. 535 6j2, 76 871, 420585, 437970, 54 9 ^o8 > 198 9 ¹⁰ '503431. 538675, 645 304, 804804, 806787, 808952; British Patent Nos. 301975, 397446; Belgian Patent No. 508 599; U.S. Patents No. 15 399/1922, 2360958, 2471 797; Swiss Patent No. 290 580; Chemie-Ingenieur-Technik, 1952, pp. 58, 60 to 65, 70, 92 to 97; "Die Braunkohle", 1929, p. 170 ff .; "Oil and Coal", 1934, pp. 216 to 219. Older patents considered: German Patent No. 934 247. 1 sheet of drawings © 609 580/450 8.56 (109 554/3 4.61}