CN2268237Y - Stepped fluidized-bed dryer - Google Patents

Abstract

The utility model provides a step type fluidized bed dryer for removing the moisture of powder. The utility model is composed of a main bed body, a step porous type gas distribution plate which is arranged horizontally and a reverse conic gas preliminary distribution device. A baffle being which is arranged in a vertical direction and can move up and down divides the main bed body into a plurality of drying chambers. A first drying chamber is provided with a stirring device to prevent the agglomeration of moist materials. The main bed body is a structure formed by a semicircular straight barrel shape and an oblong cone to make the stir more complete. The between a middle bed body is arranged below a gas distribution plate of the first drying chamber to complementing the height difference between step beds for making the entirety of the whole bed layer fluidized uniformly. The utility model has the advantages of low cost, stable operation and strong drying capacity. The utility model is suitable for drying materials with high inherent moisture and thermosensitive materials.

Description

The notch cuttype fluidized bed dryer

The utility model relates to a kind of notch cuttype fluidized bed drying device of removing solid powder moisture content.

Domestic existing horizontal multicompartment fluidized bed dryer is made up of casing, gas distribution grid and gas pre-distributor three parts usually.Casing is generally square box, and interior dress dividing plate is divided into a plurality of hothouses with casing, leaves certain interval between dividing plate and the gas distribution grid.Gas distribution grid is a porous plate.Gas pre-distributor is square box or several reverse tapers.Normal and the pneumatic conveyer dryer of this class drier makes up the drying operation of finishing wet stock after the centrifugal dehydration.The wet stock of moisture (30～40) % (wt) is dried to critical moisture content by pneumatic conveyer dryer earlier and enters fluidized bed dryer again and be dried to below the water content 0.2% (wt).This horizontal multicompartment fluidized bed dryer requires rather harshly when dry heat sensitive material to the moisture content of charging, generally will reach or near critical moisture content.When feed water content increased, this drier just was difficult to keep normal operation or effective dry, drying capacity reduction, dry back nonconforming, the grain fluidized deterioration of product water content even " bed collapses " phenomenon occurred.For this reason, German LURGI has manufactured and designed the notch cuttype fluidized bed dryer that is used for HDPE production.Be characterized in that each hothouse has the different fluid bed height of bed, the dividing plate bottom has aperture and is convenient to the bulky grain circulation, and gas distribution grid is the ceramic capillary plate, is spliced by several fritters.The wet stock of moisture (3～4) % (wt) enters this equipment and can reduce to below 0.15% (wt) through dry water content of a step, has reduced energy consumption.But because its gas distribution grid is spliced by the fritter fine plate of making pottery, structure is very complicated, involves great expense; So in addition its first hothouse be not provided with powder breaker feed water content higher, when agglomerate occurring, still might produce fluid bed " dead bed " phenomenon, influence ordinary production.

The utility model purpose is to provide that a kind of cost is low, drying capacity is stronger, is suitable for handling the notch cuttype fluidized bed dryer of high water content and heat sensitive material.

In order to achieve the above object, the utility model notch cuttype fluidized bed dryer has adopted following Design Conception.Drier integral body is made up of main bed body, agitating device, distribution device in gas-fluid, middle bed body and lower cone five parts.Connect with flange mutually between main bed body, middle bed body and the lower cone.Distribution device in gas-fluid is formed with the stairstepping welding by two identical porous type gas distribution grids of percent opening, and this gas distribution grid along continuous straight runs is separated into main bed body and lower cone to drier.Gas distribution grid top vertically is provided with dividing plate moving up and down and will leads a body and be divided into a plurality of hothouses, leaves the gap between dividing plate and the gas distribution grid and is convenient to the bulky grain circulation.At first hothouse agitating device is set and prevents wet stock (water content is higher than critical moisture content) caking and reinforced caused fluidized-bed layer non-uniform phenomenon.In order to make more even, the no dead angle of charging, main bed body adopts the straight tubular of anterior semicircle rear portion rectangle cone structure, and cone is located on certain straight section height, cone angle is 15～30 °, the employing of rectangle cone has reduced the empty tower gas velocity of equipment, reduces particle and takes out of, alleviates the load of dust collection device.Bed body in being provided with under the first hothouse gas distribution grid, adopting anterior is that semicircle rear portion is the combined structure of rectangle.In the difference in height that the installation question that solved the first hothouse gas distribution grid and polishing has been set between the ladder bed of bed body, thereby reach the whole evenly purpose of fluidisation of whole bed.Gas pre-distributor is an inverted pyramidal structures.Place dividing plate between each chamber can up-down adjustment to adjust the integral bed layer height and the residence time of material of drier.Each chamber has the different operation height of bed, from first Room to of the gradually minimizing of follow-up each chamber along with material moisture content, bed density reduces successively, thereby the fluidized-bed layer height of each chamber is increased the overall pressure drop basically identical of keeping each chamber successively, makes mode of operation more steady.Wet stock enters first hothouse and carry out the fluidization operation under agitator stirs, and flows into second Room and follow-up each chamber successively by the dividing plate top then, is difficult to the bulky grain of fluidisation each follow-up hothouse of gap inflow via the dividing plate below.Material moisture through the multicell drying is reduced to below 0.12% (wt), can satisfy technological requirement fully.Material was discharged by hothouse and was sent into feed bin this moment, and dry back tail gas is through the emptying after device gathers dust of whirlwind wind.

The utility model notch cuttype fluidized bed dryer adopts the multicell drying process, how much the deciding on the concrete process conditions and the feature of the material that is dried of hothouse.Three or four hothouses are set usually can obtain satisfied drying effect.

The utility model notch cuttype fluidized bed dryer has increased agitating device and for making stirring more abundant at first hothouse, a main bed body is designed to combine with rectangle cone structure thereby can suppress the high moisture material caking effectively and the caused fluidized-bed layer non-uniform phenomenon that feeds in raw material of the straight tube of semicircle, avoid " bed collapses ", " dead bed ", improved the equipment drying capacity.Heat sensitive material about moisture 10% (wt) is dry through one step of the utility model notch cuttype fluidized bed dryer, and water content is reduced to below 0.12% (wt).Next adopt notch cuttype porous type gas distribution grid simple in structure, that be convenient to make not only reduced cost (only for same category of device introduce price 1/10th) but also improved operational stability.

Fig. 1 is the utility model notch cuttype fluidized bed dryer front view.

Fig. 2 is the front view of the utility model notch cuttype fluidized bed dryer master bed body.

Fig. 3 is the vertical view of the utility model notch cuttype fluidized bed dryer master bed body.

Fig. 4 is the vertical view of bed body in the utility model notch cuttype fluidized bed dryer.

Below in conjunction with the drawings and specific embodiments the utility model is described in further detail.

According to shown in Figure 1, the utility model notch cuttype fluidized bed dryer is made up of main bed body (1), porous type gas distribution grid (15,16) and reverse taper gas pre-distributor (14).Gas distribution grid one (15) and gas distribution grid two (16) are stairstepping and are connected drier is divided into main bed body (1) and gas pre-distributor (14) two parts.Be provided with two dividing plates moving up and down (5,7) at fluid bed master bed body (1) along the vertical plane of Flow of Goods and Materials direction drier is divided into three hothouses (2,6,8).First Room (2) is as feed space, in establish and stir rake (4) and drive by transmission device (3).The 3rd Room (8) is used for discharging, be provided with blow-off valve (10) but and the overflow plate of up-down adjustment (9) with control residence time of material.The height of bed of each chamber has different selecting according to different bed densities.Main bed body (1) is by straight tube of semicircle and rectangle cone be combined into, as shown in Figures 2 and 3.Bed body (17) in gas distribution grid two (16) is divided into, its structure is semicircle and rectangle combining structure as shown in Figure 4.Gas pre-distributor (14) is made up of 6 reverse tapers (14), the corresponding hothouse (2,6,8) of per two reverse tapers (14), blast pipe (13) top of each reverse taper (14) side all have an awl cap plate (12) to presort the cloth effect in order to strengthen cone rigidity and gas.It is 750mm first hothouse (2) that the polyethylene of moisture 10% (wt) enters the expansion height of bed with 2000kg/h, raker stirrer (4) through 3～15r/min stirs, evenly fluidisation enters second Room (6) and the 3rd Room (8) that the expansion height of bed is 1050mm, and the bulky grain that is difficult to fluidisation flows through through dividing plate (5,7) bottom gap.Notch cuttype porous gas distribution grid (15,16) percent opening is 1.0%.Through the utility model notch cuttype fluidized bed dryer drying, the polyethylene water content is reduced to 0.12% (wt) and by discharging opening (11) discharging.

Claims (1)

1. notch cuttype multi-cell fluidized bed drier of removing solid powder moisture content, by main bed body (1), gas distribution grid (15,16) and reverse taper gas pre-distributor (14) form, it is characterized in that gas distribution grid (15,16) form by the stairstepping welding for the porous type gas distribution grid, fluid bed master bed body (1) is provided with dividing plate (5 moving up and down along the vertical plane of Flow of Goods and Materials direction, 7) drier is divided into a plurality of hothouses (2,6,8), establishing raker stirrer (4) in first hothouse (2) is driven by transmission device (3), last hothouse (8) be provided with blow-off valve (10) but and the overflow plate of up-down adjustment (9) with control residence time of material, main bed body (1) is by straight tube of semicircle and rectangle cone be combined into, divide into the middle bed body of forming by semicircle and rectangle (17) at gas distribution grid two (16), gas pre-distributor (14) is made up of a plurality of reverse tapers (14), the corresponding hothouse (2 of per two reverse tapers (14), 6,8), an awl cap plate (12) is established in the blast pipe (13) of each reverse taper (14) side top.

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