Drum sieve in the preparing grass material screening technology
Technical field
The utility model relates to and is used for grass raw material melting process and screens used drum sieve.
Background technology
Adopt before the dogstail raw pulp, at first to get the raw materials ready to the dogstail raw material, the existing grass raw material flow process of getting the raw materials ready roughly comprises section, screening and three main operations of dedusting, and what the root with dogstail that the factory that has also tried one's best before section, fringe, leaf, go rotten part and silt particle etc. were done the best removes.The purpose of section is for the dogstail raw material is cut off, dogstail raw material after the processing can feed chaffcutter continuously and be cut into blade, then with blade and impurity substances thereof, delivering to screening machine by belt conveyor screens, existing screening is generally carried out in drum sieve and/or flat screen, on cylinder and/or plansifter, grain grass joint is the sieve aperture by 12mm then, fall the below, dust, the grass bits wait lighter material then in company with air-flow, by being positioned at two arcuation sieve plates (sieve aperture 1.5-2mm) of top, selection by winnowing chamber, to overflow from top, selection by winnowing chamber, the raw material after the screening carries out dedusting at dust removal machine.
Screening installation of the prior art generally includes following several: rotary strainer, plansifter.Rotary strainer is divided into the individual layer and double-deck rotary strainer, in " pulping process and equipment " book that Chinese Light Industry Press publishes in October, 2000, has disclosed the characteristics of the structure of this individual layer and double-deck rotary strainer.The main body of individual layer rotary strainer is the scroll drum with sieve aperture, and sieve plate divides two sections, and at the general sieve aperture of miner diameter end little (diameter 4-8mm), and second section sieve aperture is bigger, and (diameter is 30mm, or (15-30) * (60-80) mm slit.The principle of this drum sieve is that the wood chip after cutting is sent into from miner diameter end, rotates with cylinder, and the wood fragments bits fall by the first end sieve aperture to be told, qualified wood chip then falls from second sector hole, send chip bin, thick, rectangular staying in the cylinder discharged from big end, sends to and cuts.Yet the drum sieve of this structure can only be finished pending raw material, is meant a scalping of wood chip herein.
In order to reach better separating effect, in this book, also disclosed double-layer cylinder screen, it is to be contained on the framework of same main shaft by the different scroll drum screen jacket of two layer screen hole size to constitute.Nexine sieve plate sieve aperture is big, the sieve aperture of outer sieve plate is little, wood chip is sent into the nexine cylinder from small end, rotate with cylinder, accepted chips, the wood fragments bits fall into outer cylinder by sieve aperture, and thick, the rectangular the inside of staying, discharge by big end, the wood fragments bits are discharged by outer sieve aperture, and accepted chips is stayed the inside and discharged from big end, and concrete structure chart is referring to figure one, pending raw material passes through double-layer cylinder screen, raw material at first carries out scalping in the nexine rotary screen, then carry out dusting cover in outer cylinder, thus by this screening of two ones better with pending impurities in raw materials place to go.In the text not to the slot size of double-layer cylinder screen, shape is described in detail, and the raw material that the double-layer cylinder screen in the literary composition is handled is wood chip, is different from the pending grass raw material in the utility model.
In " pulping process and equipment " book, also disclosed and shaken that plansifter is this to be used to screen the equipment of getting the raw materials ready, this equipment has compact conformation, reliable and the big advantage of production capacity, but it is more suitable in the wood chip middle use of getting the raw materials ready, if be used to separate the grass raw material, can only carry out scalping to the dogstail raw material, can't reach the purpose of dusting cover.
At the shortcoming of screening installation of the prior art, the utility model provides a kind of drum sieve that is used for the preparing grass material screening technology.
The utility model content
The purpose of this utility model is to provide a kind of compact equipment, and is reliable, is used for the drum sieve that the grass raw material is got the raw materials ready and screened.
For achieving the above object, the technical solution adopted in the utility model is: a kind of preparing grass material screening technology drum sieve that is used for is provided, sieve and outer sieve in comprising, the sieve aperture of sieve is that the length of side is the square hole of 30-50mm in described, the percent opening of interior sieve is 76.68-85.5%, the sieve aperture of outer sieve is that diameter is the circular port of 4-8mm, and the percent opening of outer sieve is 29.91-75.47%.With respect to prior art different be, the sieve aperture of sieve is designed to square hole in the drum sieve of the present utility model, this is to get the raw materials ready because the drum sieve in the utility model is used for the dogstail raw material, pending dogstail raw material at first enters the interior sieve of drum sieve, repeatedly testing discovery through the utility model technical staff stops from the sieve aperture of interior sieve when the blade and the strap of length more than 80mm that interior sieve adopts square sieve aperture to be mixed with in being easier to pending dogstail raw material with respect to the sieve aperture of circle, and qualified blade, be length less than the outer sieve that 80mm is easy to enter by the sieve aperture of interior sieve drum sieve, realized the scalping purpose in the screening process.Compare with interior sieve, the screening area of sieve in the screening area of outer sieve is far smaller than, its objective is: the blade that enters outer sieve by sieve in the drum sieve, outside under Shai the high speed rotating, the tiny impurity that is mixed with in the blade, that is: leaf, sheath, fringe, marrow, grass joint, silt particle sift out from sieve aperture, thereby have realized the purpose of the dusting cover in the screening process.
Interior sieve described in the utility model and outer sieve are rotatingcylindrical drum, described interior sieve and coaxial being sleeved on the main shaft framework of outer sieve.The interior sieve of existing double-layer cylinder screen and outer the sieve usually all coning, and the interior sieve of drum sieve of the present utility model and outer sieve are all cylindrical.
The distance of sieve and outer sieve is 30-45cm in described in the utility model.In distance between sieve and the outer sieve to be made as 30-45 centimetre purpose be for when drum sieve keeps treating capacity, still can work smoothly, the excessive accumulation in drum sieve of pending dogstail raw material can not take place, and screens the operation that has some setbacks.
Any two adjacent sieve apertures of sieve have a shared limit in described in the utility model.Because the square sieve aperture of the interior sieve in the utility model and four sieve apertures around it are side-by-side mutually, and each sieve aperture all has a common edge with its contiguous sieve aperture.
The length of side of sieve sieve aperture is preferably 30-40mm in described in the utility model.
The diameter of outer sieve sieve aperture described in the utility model is preferably 4-6mm.
Sieve spiral and outer sieve spiral in the inner surface of the inner surface of the interior sieve of drum sieve described in the utility model and outer sieve is separately installed with.Interior sieve spiral and outer sieve spiral are followed the passive rotation of rotation of interior sieve and outer sieve respectively, and can be with the axial direction promotion of raw material along drum sieve with this.
Sieve spiral and described interior sieve and described outer sieve spiral and described outer connected mode of sieving are welding in described in the utility model.
Drum sieve described in the utility model angle with respect to the horizontal plane is 6-12 °, preferred 8-10 °.
Sieve no longer selects for use sieve aperture of the prior art to be circular sieve in the drum sieve of the present utility model, is foursquare square hole screen but select sieve aperture.
Wherein: by described screening of sieving in drum sieve, the qualified blade of screening and fine impurities at first enter outer sieve by the square sieve aperture on the interior sieve of drum sieve.Strap is shifted the impurities removal exit with growing grass onto by interior sieve spiral.Thereby the interior sieve at drum sieve has been finished qualified blade, just length less than the blade of 80mm and strap and length greater than the separation screening between the blade of 80mm.
Sieve outside then the blade that sifts out from interior sieve enters, the percent opening of outer sieve is 29.91-75.47%, because the rotary speed of the outer sieve of drum sieve is fast, angular speed reaches 18-21 rev/min.The high speed of sieve rotation outside down, the leaf that is mixed with in the blade, sheath, fringe, marrow, grass joint, silt particle are owing to self is in light weight, so the high speed of sieve rotation outside down, be more convenient for being screened in a large number from the sieve aperture of the outer sieve of drum sieve, the blade after the screening is piled the material outlet place by outer sieve spiral and is discharged to the next stage drum sieve.Can directly not carry out boiling in the screening of carrying out the next stage drum sieve yet.Therefore finished qualified blade and the impurity that wherein is mixed with at the outer sieve of drum sieve: as leaf, sheath, fringe, marrow, grass save, the separating of silt particle.
Because drum sieve itself and horizontal plane have a certain degree, so when drum sieve rotates, locomotivity before blade is oriented, sieve spiral and outer sieve spiral in the inside and outside sieve inner surface of drum sieve has respectively simultaneously, blade is because it in light weight, so at interior sieve spiral with sieve the other end exit that slides to drum sieve under the promotion of spiral outward.
Description of drawings
Fig. 1 is the schematic diagram of drum sieve;
Fig. 2 is the sectional view along A-A of drum sieve;
Fig. 3 is a sieve schematic diagram in the drum sieve;
Fig. 4 is that drum sieve sieves schematic diagram outward.
The specific embodiment
Following embodiment is used to explain the utility model but does not limit the utility model.
Embodiment 1
Present embodiment is a kind of technical scheme of the utility model drum sieve, referring to Fig. 1, the schematic diagram of the utility model drum sieve, 1 is the outer sieve of drum sieve, 2 is the interior sieve of drum sieve, interior sieve 2 and outer sieve 1 are cylindrical, on the coaxial main shaft framework 3 that is installed in drum sieve, interior sieve 2 and the distance of sieving outward between 1 are 42.5 centimetres, referring to Fig. 3, and the schematic diagram of interior sieve 2, the sieve aperture of interior sieve 2 is for being arranged in square hole together mutually, the square hole that each square hole is all adjacent with it has a common edge, and the length of side a of sieve aperture is 30mm, and area is 900mm
2On the sieve 2, the screen number of every square metre distribution is 852 in columniform.Referring to Fig. 4, sieve 1 schematic diagram outward, 1 sieve aperture of outer sieve is that diameter d is the circular port of 4mm, the area of each sieve aperture is 12.56mm
2, the screen number on the outer sieve 1 of every square meter is 23821.The axis of drum sieve of the present utility model and the angle of horizontal plane are 10 °.
Embodiment 2
Present embodiment is second kind of technical scheme of the utility model drum sieve, referring to Fig. 1, the schematic diagram of the utility model drum sieve, 1 is the outer sieve of drum sieve, 2 is the interior sieve of drum sieve, interior sieve 2 and outer sieve 1 are cylindrical, on the coaxial main shaft framework 3 that is installed in drum sieve, interior sieve 2 and the distance of sieving outward between 1 are 30 centimetres, referring to Fig. 3, and the schematic diagram of interior sieve 2, the sieve aperture of interior sieve 2 is for being arranged in square hole together mutually, the square hole that each square hole is all adjacent with it has a common edge, and the length of side of sieve aperture is 50mm, and area is 2500mm
2On the sieve 2, the screen number of every square metre distribution is 342 in columniform.Referring to Fig. 4, the schematic diagram of outer sieve, sieving 1 sieve aperture outward is that diameter d is the circular port of 6mm, the area of each sieve aperture is 28.26mm
2, the screen number on the outer sieve of every square meter is 18426.The axis of drum sieve of the present utility model and the angle of horizontal plane are 6 °.
Embodiment 3
Referring to Fig. 1, the straw length that to get 5 tons of moisture content be 10%-22% is the segment of 300-350mm, cut into slices, be cut into blade that length is 20-80mm and its grass joint rubbed and come, section and rub after the blade that obtains be transported into and carry out dedusting in the cyclone separator, blade can not be drawn out of owing to having bigger weight, then be transported in the drum sieve and screen, the impurity content that enters in the blade of drum sieve is 18%, drum sieve is inclined relative to horizontal placement, and the angle of inclination between the horizontal plane is 6 °, the sieve aperture of sieve 2 is a square hole on the drum sieve, length of side a is 30mm, rotating speed is 10 rev/mins, the sieve aperture of outer sieve 1 is a circular hole on the drum sieve, the rotating speed of outer sieve is 21-29 rev/min, blade after the dedusting at first enters the interior sieve 2 of drum sieve, when drum sieve sways, the qualified blade interior sieve 2 by drum sieve enters and sieves 1 outward under interior sieve spiral 4 promotes, strap in the impurity that is mixed with in the blade after the dedusting and the length that is mixed with in blade are stopped greater than the sieve aperture of 80mm blade at interior sieve 2, and under interior sieve spiral 4 promotes, deliver to the exit and discharge, the result shows: strap, at interior sieve 2 elimination factors more than 96%.Because outer sieve 1 has big velocity of rotation, and sieve outward that diameter d is arranged on 1 is the circular hole of 6mm, be removed so enter the impurity middle period, sheath, fringe, marrow, grass joint, the silt particle that are mixed with in the blade in the outer sieve 1.The screening operation was carried out altogether 110-120 minute, and the blade that then enters outer sieve 1 sieves under the promotion of spiral 5 outside, enters the belt conveyer scale weighing, enters rotary spherical digester at last and carries out boiling.The content of impurity 18% brings up to 21% before screen, then carry out the operation of shove, washing, bleaching, the result shows that when obtaining whiteness be in the paper pulp of 72%IS0, the minimizing 2% of used alkali lye during the blade boiling, yet adopt existing dry raw material preparation, the index of paper is significantly improved, and has realized the fine fodder boiling.
Embodiment 4
Referring to Fig. 1, get 5 tons of moisture content for to cut into slices less than 10% wheat straw, be cut into the segment that length is 20-50mm, the wheat straw sheet that obtains after the section is transported into and carries out dedusting in the cyclone separator, the little dust of density in the blade, the grass bits, fringe is extracted out from cyclone separator, the wheat straw sheet can not be drawn out of owing to itself having bigger weight, then be transported in the drum sieve and screen, the impurity content that enters in the wheat straw sheet of drum sieve is 20%, drum sieve is inclined relative to horizontal placement, and the angle of inclination between the horizontal plane is 8 °, sieve aperture on the interior sieve 2 of drum sieve is a square hole, length of side a is 30mm, the sieve aperture of the outer sieve 1 of drum sieve is that diameter d is the circular hole of 4mm, blade after the dedusting at first enters the interior sieve 2 of drum sieve, the rotating speed of interior sieve 2 is 10 rev/mins, the rotating speed of outer sieve 1 remains on 21 rev/mins, when drum sieve sways, under interior sieve spiral 4 promotes, enter and sieve 1 outward less than the blade of the 50mm interior sieve 2 by drum sieve, strap in the impurity that is mixed with in the blade after the dedusting and the length that is mixed with in blade are stopped greater than the sieve aperture of 80mm blade at interior sieve 2, and under interior sieve spiral 4 promotes, deliver to the exit and discharge, because wheat straw sheet itself is in light weight, so when drum sieve sways, screen the sieve aperture from interior sieve 2, be mixed in the wheat straw sheet weight simultaneously and beat again the impurity of band etc. when drum sieve sways, discharge from discharging opening one side of drum sieve, the result shows: strap, at interior sieve 2 elimination factors more than 96%.Because outer sieve 1 has big velocity of rotation, and sieve outward and have the circular hole that diameter d is 4mm on 1, the outer sieve 1 that tiny impurity and qualified blade enter drum sieve screens, the leaf that is mixed with in tiny impurity and the blade, sheath, fringe, marrow, the grass joint, silt particle sieves in 1 outside and is removed, the screening operation was carried out altogether 120-150 minute, the result shows in the screening operation, the content of the impurity in the blade 18% brings up to 20% before screen, in order to reach the effect that better screening separates, the blade that had sieved can be screened by another or same drum sieve once more, the wheat straw sheet that sifts out from drum sieve is sent into rotary spherical digester and is carried out boiling, then carry out shove, washing, the operation of bleaching, the result shows that when obtaining whiteness be the paper pulp of 78%ISO, the concentration of used alkali lye is 12% during boiling, yet adopt existing dry raw material preparation, realized that the fine fodder boiling has improved the yield of slurry, on average improves 4% point.5 tons of blades obtain the paper pulp that whiteness is ISO78% in boiling after shove, the washing, and the quality of paper pulp obviously improves, and weight in wet base can reach 2.2-2.4g.