Drying and gas or vapor contact with solids – Apparatus – With fluid current conveying of treated material
Patent
1994-02-28
1995-02-28
Gromada, Denise L.
Drying and gas or vapor contact with solids
Apparatus
With fluid current conveying of treated material
34582, 34360, 291636, F26B 1700
Patent
active
053925319
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a bed plate for a fluidized bed apparatus, a fluidized bed apparatus comprising such bed plate, and to a method for making the bed plate.
Fluidized bed apparatuses are used for example as dryers and/or agglomerators, and for otherwise treating a powdered or particulate product with gas or air, for example for cooling the product, or as fluid bed combustors for combustion of powdered or particulate fuel, etc. Such fluid bed apparatuses may comprise a bed plate which is made from sheet metal having a plurality of air or gas distributing openings or perforations punched therein. The openings or perforations may be plain, circular openings. The diameter of such openings are usually chosen as small as possible in order to reduce the amount of powdered or particulate product which may fall through the openings of the bed plate into an underlying air or gas plenum chamber, for example, when the operation of the fluid bed is interrupted or stopped.
Bed plates having openings or perforations of the so-called "gill type" are also known, for example from U.S. Pat. Nos. 3,821,342 and 4,033,555. This type of openings or perforations define fluidizing flows of air or gas having a flow component which is directed along the upper surface of the bed plate, for example towards a product outlet of the fluid bed. Such flow component directed towards the product outlet renders it possible to obtain a self-clearing or self-emptying effect when the operation of the apparatus is stopped, and the fall-through of products may thereby be further reduced.
An opening or perforation of the "gill-type" may be made by cutting a slit or slot in the sheet metal so as to form opposite edges, and by pressing one of the opposite edge portions out from the plane defined by the sheet metal. Such depression of one edge portion causes it to be moved away from the other whereby the slit or slot is opened also when viewed in a direction at right angles to the plane of the sheet metal. This means that the product in a fluid bed formed on a bed plate having openings of the conventional gill type may to some extent fall through the openings of the bed plate, when the supply of fluidizing air or gas is stopped or interrupted. In cases where even such reduced fall-through of product is unacceptable it is necessary to use a bed plate with nozzles of the type disclosed in the published UK patent application GB 2 015 377. This known, rather complicated and expensive bed plate cannot be made by punching sheet metal. Furthermore, this known bed plate can only be made with a relatively small number of openings per unit of area because of relatively large minimum dimensions of each opening.
The present invention provides bed plate which may be made from sheet metal by simple cutting and deforming operations, and which may be made so that fall-through of the product to be fluidized is substantially reduced or prevented.
The present invention provides a bed plate for a fluidized bed apparatus, said bed plate, which is made from sheet metal, defining a first general side surface and having a plurality of gas distributing openings formed therein, each of said openings being defined between first and second opposite edge portions, of which at least the first edge portion has been pressed out from said general side surface, and the bed plate according to the invention is characterized in that the thickness of at least part of at least one of said first and second edge portions has been reduced so as to increase the extension thereof along said first general side surface, and so as to thereby reduce or eliminate the orthographic projection on said first general side surface of the opening defined between said first and second edge portions.
The first and/or second edge portion may be deformed in any manner causing a reduction of the transverse spacing of the first and second edge portions as viewed in a direction at right angles to the first side surface.
Basically, the bed plate according to the invention may be made in a similar man
REFERENCES:
patent: 1802960 (1931-04-01), Simonds
patent: 2728316 (1955-12-01), Oberg et al.
patent: 3611765 (1971-10-01), Harvey
patent: 3733056 (1973-05-01), Fong
patent: 4724794 (1988-02-01), Itoh
patent: 4787152 (1988-11-01), Mark
patent: 4885848 (1989-12-01), Christensen
Bonde Mikael
Christensen Mogens
Madsen Benny
Gromada Denise L.
Niro Holding A/S
LandOfFree
Bed plate for a fluidized bed apparatus and a method for making does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Bed plate for a fluidized bed apparatus and a method for making , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bed plate for a fluidized bed apparatus and a method for making will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-839547