CN2365047Y - Straw pulp black liquid pressing machine - Google Patents

Abstract

The utility model relates to a straw pulp black liquor squeezer which comprises an outer shell, a screw shaft and a screen cylinder, wherein, both ends of the outer shell are provided with a feed port and a discharge port; the screw shaft is a cylindrical screw with equal pitch, and the root diameter of the screw is in a diameter changeable type; the screen cylinder is hooped into a cylindrical sparrow cage type by micro strips, filter liquor outlets among screen strips are elongated screen seams, and the inner diameter of the screen cylinder is provided with an anti-skid strip. The utility model uses the changeable root diameter of the screw to squeeze pulp, and uses the elongated screen seams to prevent fiber from following the filter liquor to flow out so as to obtain high extraction rate of black liquor.

Description

Straw pulp black liquor is extracted machine

The utility model relates to a kind of spiral of straw pulp black liquor and extracts extraction equipment, and it is applicable in the paper industry separating straw pulp and its black digestion liquid.

In the careless class chemical pulping process of paper industry, the overwhelming majority is with alkali (or imonium) and together boiling of grass as raw material.After boiling, the cellulose in the raw material is dissociated out becomes the needed soft fibre of papermaking, and other components are dissolved into and become black liquor in the cooking liquor.

Black liquor and fiber are separated, black liquor through concentrating, after burning, the causticization, is reduced to " alkali " again and (Na0H) is recycled and reused for boiling.This process is called alkali and reclaims.In order to reclaim alkali to greatest extent and to save the steam of concentrated black liquor, need from straw pulp, extract concentration maximum, black liquor as much as possible, preferably extraction Normal juice black liquor as much as possible.

The black liquor major part is free between fiber and the fiber, partly is present in the lumen, is present on a small quantity in the cell membrane hole of fiber in addition, extracts black liquor and it will be separated from fiber exactly as far as possible.Extracting the mechanism of black liquor equipment, with the mechanism of pulp washing process concentrator, is consistent in theory, and three kinds of mechanism are arranged, the one, and filtering means dehydration effect, the 2nd, extrusion dehydration effect, the 3rd, displacement diffusion.The former two extracts the black liquor between fiber and the fiber, and the latter is that the black liquor with fibrous inside cements out with thin liquid or water and is diffused in the solution, so that further extract.

At present, acting as main extraction equipment with filtering means dehydration has: vacuum pulp washing machine, pressure wash engine.Belt pulp washing machine.Extraction equipment with the squeezing action dehydration has: single-screw press master, Var-nip press etc.The dewatering speed Q[m of two kind equipments ³/ m ².s] with pressure difference P[Kg/cm ²], the average diameter d[m in duct in the coefficient of efficiency n of filter area and the filtering layer] square be directly proportional, with the viscosity, mu [kg.s/m] of filtrate, the thickness L[m of filtering layer] and filtering layer in degree of crook coefficient a[＞1 in duct] be inversely proportional to available following expression formula. $Q=\frac{4{\mathrm{pnd}}^2}{32y.\mathrm{la}}$

Know from above-listed formula: intensified pressure p and coefficient of efficiency n, reduce thickness of filter bed L, can improve dewatering speed Q.But because slurry section is in extrusion process, the channel diameter d of filtering layer can diminish between the fiber, therefore in extrusion process.P, L and a allocated to obtain effect preferably.

So far, known acroll press washer has two kinds: the one, and housing and helical axis all are tapered single-screw press masters, another kind is a Shandong INI type Double screw pulp extruder.Their screen cylinder all is an employing garden sieve aperture , or 0 1.8～zero 3mm, fiber stops up sieve aperture easily, run off big (0.5-3%), the taper single-screw makes the aperture d of filtering layer diminish in extrusion process, and Double screw pulp extruder pressure is less than normal, the both has limited dewatering speed Q, thereby the low yield of pulp concentration is not high.

The purpose of this utility model provides a kind of nothing and stops up, and pulp concentration is big, output is high, and straw pulp black liquor spiral simple in structure, small investment is extracted machine.

The purpose of this utility model is achieved in that the straw pulp black liquor spiral extracts machine and comprise shell, helical axis and screen cylinder.The shell two ends are charging aperture and discharging opening.Shell is a polygonal.Screen cylinder is cylinder " sparrow cage " shape, it is characterized in that h=2mm is arranged on the internal diameter, and the tread plate of b=16mm " sparrow cage " is pricked by little shape bar hoop and formed, filtrate channel between little shape bar is a slit, the A section is stitched wide b=0.35-0.4mm, B section 1.5m-2mm, and the C section is stitched wide 3.0-4.0mm.Helical axis is equidistant Reducing screw (end that is helical axis directly is multidiameter).The overall compression ratio K=2.2-3.0 of machine

Below in conjunction with accompanying drawing, the utility model is further described by embodiment:

Fig. 1. be the structural representation of embodiment of the present utility model:

1. shell 2. charging apertures 3. discharging openings 4. screen cylinders 5. helical axis 6. pull out glassware

7. filtrate collector groove 8. shaft coupling A, B, C represent to sieve the segmentation of seam width

Fig. 2. be the structural representation of sparrow cage screen cylinder:

4a. the seam width of miniature grating 4b. tread plate 4c. locking strap 4d. sieve seam 4e. micro-bars

The utility model front is connected with the spraying pot of storing slurry, and the back is connected with the slurries mixer.During use, make helical axis 5 and helical rotation with motor and deceleration device by shaft coupling 8 earlier, and then the slurry in the spraying pot is sent into screen cylinder from charging aperture.Slurry advances in the screen cylinder 4 that tread plate is arranged vertically, does the rotation that adapts to simultaneously.In this process, slurry at first passes through the A section of screen cylinder finedraw, and black liquor leaches from sieve seam 4d and enters in the black liquor collector groove 7.In the A of screen cylinder 4 section.Because the sieve seam is less than length (the fine paper length L=0.66～3.1mm of straw pulp of fiber, fiber width b=6-48um) can from sieve seam, not bleed and go in the black liquor collector groove, and only leach black liquor, even (the granule fiber clamp is arranged in the filter seam, because seam and axle are in the same way, little shape filter bar is very narrow, and particle is also easily washed away in advancing), thereby slurry is concentrated.Slurry advances vertically, constantly be concentrated to be slurry group, thereby the sieve of screen cylinder seam is widened piecemeal.Slurry is in the process of advancing vertically, and the diameter of helical axis constantly becomes greatly, the radially attenuation constantly of thickness L of slurry layer, and the pressure P that the slurry layer is subjected to also constantly strengthens, thereby the flow velocity Q of filtrate also continues to increase.Slurry is extruded very driedly like this, and most (60%-70%) Normal juice black liquor is able to extract from slurry, extruding stem slurry constantly released by setting gauge 8 at the discharging opening place, enter the slurries mixer of back.

The slurry of extruding stem is diluted by rare black liquor in the slurries mixer of the utility model back, and through stirring, the black liquor that diffuses out in the fibrocyte extracted in order to next stage.

Claims (1)

1, straw pulp black liquor is extracted machine, comprises shell, helical axis, and screen cylinder.There are charging aperture and discharging opening in the shell two ends.Spiral is arranged on the helical axis, it is characterized in that spiral is an isometric circle cylindricality spiral, the end of spiral directly is a reducing, and its compression turns to K=2.2～3.0.Screen cylinder is bundled into the sparrow cage type by the micro-bars hoop; Filtrate outlet between micro-bars and the micro-bars is very thin slit, stitches wide C=0.35～4mm; On the screen cylinder internal diameter circumference tread plate is arranged.

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