阅读说明：本技术 一种以刨花为原料的机械浆生产系统及生产工艺 (Mechanical pulp production system and production process using wood shavings as raw materials ) 是由 韩冲 宋留 黄宏权 杨文恒 余汪洋 于 2020-08-05 设计创作，主要内容包括：本发明公开了一种以刨花为原料的机械浆生产系统及生产工艺,生产系统包括依次设置卸料仓、粗磨装置、精磨装置、第一浆池、压力筛、第二浆池；生产工艺通过过上述的生产系统实现：刨花的进料和存放；软化刨花的内部纤维,在常压状态下,采用热水和反应助剂对刨花进行浸渍,使刨花得到软化；对软化后的刨花进行粗磨处理,对软化后的刨花进行揉搓,使软化后的刨花疏解成带有纤维束的纤维浆料；对带有纤维束的纤维浆料进行精磨处理,将带有纤维束的纤维浆料研磨成单根纤维形态的纤维浆料；将单根纤维形态的纤维浆料进行压力筛选,筛选出达到使用需求的机械浆。本发明利用刨花为机械浆原料,省去原木加工和筛选过程,节约占地面积和设备投资费用。(The invention discloses a mechanical pulp production system and a production process by taking wood shavings as raw materials, wherein the production system comprises a discharge bin, a coarse grinding device, a fine grinding device, a first pulp tank, a pressure screen and a second pulp tank which are sequentially arranged; the production process is realized by the production system: feeding and storing the wood shavings; softening internal fibers of the wood shavings, and soaking the wood shavings in hot water and a reaction auxiliary agent under a normal pressure state to soften the wood shavings; coarsely grinding the softened wood shavings, and kneading the softened wood shavings to untwin the softened wood shavings into fiber slurry with fiber bundles; carrying out fine grinding treatment on the fiber pulp with the fiber bundles, and grinding the fiber pulp with the fiber bundles into fiber pulp in a single fiber form; and (3) carrying out pressure screening on the fiber pulp in the single fiber form, and screening out the mechanical pulp meeting the use requirement. The invention uses wood shavings as the raw material of the mechanical pulp, saves the processes of log processing and screening, and saves the occupied area and the equipment investment cost.)

1. A mechanical pulp production system taking wood shavings as raw materials is characterized by comprising a discharging bin, a discharging bin and a feeding bin, wherein the discharging bin is sequentially arranged and used for storing and feeding; the reaction bin is used for softening fibers in the wood shavings, the reaction bin is a normal-pressure reaction device, and hot water and a reaction auxiliary agent are filled in the reaction bin; a coarse grinding device for fluffing the softened wood shavings into a fiber slurry with fiber bundles, wherein the coarse grinding device rubs the softened wood shavings to separate and free single fibers; a refining device for grinding the fiber slurry with the fiber bundles into fiber slurry in the form of individual fibers; a first stock chest for storing and stirring single fiber form stock; the pressure screen is used for screening the fiber pulp in the form of single fibers in the first pulp pond; and the second pulp tank is used for storing the screened mechanical pulp.

2. A system for the production of mechanical pulp from wood shavings according to claim 1 wherein said wood shavings are transported to a discharge bin by a belt conveyor, and a de-ironing separator is provided on said belt conveyor to remove ferrous metal from the wood shavings which have become mixed together.

3. The system for producing mechanical pulp from wood shavings according to claim 1, wherein a spray means is provided above said discharge bin, said spray means spraying water in the direction of said discharge bin to force said wood shavings into said discharge bin by said spray.

4. A system for producing mechanical pulp from wood shavings according to claim 1, wherein an agitator is disposed within said first pulp tank, said agitator agitating within said first pulp tank to maintain a constant concentration of pulp stored within said first pulp tank.

5. Mechanical pulp production system from wood shavings as claimed in claim 1, wherein said screen mesh of said pressure screen is a slotted screen, said slotted screen having a width of 0.15-0.25 mm.

6. The system of claim 5, wherein a tail pulp grinder is disposed between the pressure screen and the second pulp chest, the pulp passing through the screen of the pressure screen enters the second pulp chest, and the pulp not passing through the screen of the pressure screen enters the tail pulp grinder, and is ground again and defibered to enter the second pulp chest.

7. A mechanical pulp production process taking wood shavings as raw materials is characterized by comprising the following steps:

feeding and storing the wood shavings, wherein spray water is adopted to prevent the wood shavings from loosening in the feeding process;

softening internal fibers of the wood shavings, and soaking the wood shavings in hot water and a reaction auxiliary agent under a normal pressure state to soften the wood shavings;

coarsely grinding the softened wood shavings, and kneading the softened wood shavings to untwin the softened wood shavings into fiber slurry with fiber bundles;

carrying out fine grinding treatment on the fiber pulp with the fiber bundles, and grinding the fiber pulp with the fiber bundles into fiber pulp in a single fiber form;

and (3) carrying out pressure screening on the fiber pulp in the single fiber form, and screening out the mechanical pulp meeting the use requirement.

8. A process for producing mechanical pulp from wood shavings according to claim 1 wherein ferrous metal is removed from the wood shavings by means of an iron remover prior to feeding the wood shavings.

9. The process for producing mechanical pulp using wood shavings as raw material according to claim 1, wherein in the step of softening the internal fibers of the wood shavings, the temperature of the hot water is maintained at 100 ℃, the reaction aid is sodium hydroxide, the concentration of the reaction aid is 10% -20%, and the treatment time is 30-120 min.

10. The process for producing mechanical pulp from wood shavings as claimed in claim 1, wherein in the step of pressure screening, the screening is performed by means of a slotted screen, the width of the slotted screen is 0.15-0.25mm, the pulp passing through the slotted screen is the mechanical pulp meeting the use requirement, and the pulp not passing through the slotted screen needs to be ground again and defibered to obtain the mechanical pulp meeting the use requirement.

Technical Field

The invention relates to the field of mechanical pulp production and manufacturing, in particular to a mechanical pulp production system and a production process by taking wood shavings as raw materials.

Background

The mechanical pulp has higher yield and is widely applied to paper types with low strength requirements, such as coated paper, bobbin paper, light printing paper and the like. The traditional mechanical pulp production process comprises the processes of wood chipping, wood chip screening and washing, dehydration, preheating, impregnation, hot grinding and fine grinding and the like, the occupied area of equipment is large, and the energy consumption is high.

The wood shavings are a flaky or strip-shaped thin wood material in the wood processing process, have good self-cleaning degree and low impurity rate, and have better length reserved in the fiber direction, thereby having better papermaking utilization value.

Disclosure of Invention

The invention aims to solve the technical problem of providing a mechanical pulp production system and a production process by taking wood shavings as raw materials.

In order to solve the technical problem, the invention provides a mechanical pulp production system taking wood shavings as raw materials, which comprises a discharging bin, a discharging bin and a feeding bin, wherein the discharging bin is sequentially arranged and used for storing and feeding; the reaction bin is used for softening fibers in the wood shavings, the reaction bin is a normal-pressure reaction device, and hot water and a reaction auxiliary agent are filled in the reaction bin; a coarse grinding device for fluffing the softened wood shavings into a fiber slurry with fiber bundles, wherein the coarse grinding device rubs the softened wood shavings to separate and free single fibers; a refining device for grinding the fiber slurry with the fiber bundles into fiber slurry in the form of individual fibers; a first stock chest for storing and stirring single fiber form stock; the pressure screen is used for screening the fiber pulp in the form of single fibers in the first pulp pond; and the second pulp tank is used for storing the screened mechanical pulp.

In a preferred embodiment of the invention, the wood shavings are conveyed to the discharge bin by a belt conveyor, and an iron remover is arranged on the belt conveyor and can remove iron metals mixed together in the wood shavings.

In a preferred embodiment of the present invention, a spraying device is disposed above the discharging bin, and the spraying device sprays water in the direction of the discharging bin, so that the shavings are pressed into the discharging bin by the water spray.

In a preferred embodiment of the present invention, the slurry tank further comprises a stirrer disposed inside the first slurry tank, wherein the stirrer stirs inside the first slurry tank to keep the concentration of the slurry stored inside the first slurry tank stable.

In a preferred embodiment of the invention, the screen mesh of the pressure screen is a slotted screen, and the width of the slotted screen is 0.15-0.25 mm.

In a preferred embodiment of the invention, a tail pulp disc mill device is further arranged between the pressure screen and the second pulp tank, the pulp passing through the screen of the pressure screen enters the second pulp tank, and the pulp not passing through the screen of the pressure screen enters the tail pulp disc mill device, is milled and defibered again and then enters the second pulp tank.

In order to solve the technical problem, the invention also provides a mechanical pulp production process taking wood shavings as raw materials, which comprises the following steps:

feeding and storing the wood shavings, wherein spray water is adopted to prevent the wood shavings from loosening in the feeding process;

softening internal fibers of the wood shavings, and soaking the wood shavings in hot water and a reaction auxiliary agent under a normal pressure state to soften the wood shavings;

coarsely grinding the softened wood shavings, and kneading the softened wood shavings to untwin the softened wood shavings into fiber slurry with fiber bundles;

carrying out fine grinding treatment on the fiber pulp with the fiber bundles, and grinding the fiber pulp with the fiber bundles into fiber pulp in a single fiber form;

and (3) carrying out pressure screening on the fiber pulp in the single fiber form, and screening out the mechanical pulp meeting the use requirement.

In a preferred embodiment of the present invention, the method further comprises removing ferrous metal from the strands using a de-ironing separator prior to feeding the strands.

In a preferred embodiment of the present invention, the step of softening the internal fibers of the wood shavings further comprises maintaining the temperature of the hot water at 100 ℃, wherein the reaction aid is sodium hydroxide, the concentration of the reaction aid is 10% -20%, and the treatment time is 30-120 min.

In a preferred embodiment of the invention, in the step of pressure screening, screening is performed by using a slotted screen, the width of the slotted screen is 0.15-0.25mm, the slurry passing through the slotted screen is mechanical slurry meeting the use requirement, and the slurry not passing through the slotted screen needs to be ground and defibered again to achieve the mechanical slurry meeting the use requirement.

The invention has the beneficial effects that:

compared with the prior art, the mechanical pulp production system using wood shavings as raw materials has the advantages that wood shavings are processed into mechanical pulp capable of making paper by using the wood shavings as the raw materials through the discharge bin, the reaction bin, the coarse grinding device, the fine grinding device, the first pulp tank, the pressure screen and the second pulp tank, and in the production system, raw wood processing and screening equipment are omitted, so that the occupied area and the equipment investment cost are saved.

The mechanical pulp production process using wood shavings as raw materials, provided by the invention, has the advantages that the wood shavings are softened, coarsely ground and finely ground, pressure screening is carried out, the wood shavings are used as the raw materials to produce the mechanical pulp, wood resources are comprehensively utilized, the wood shavings are clean, and the processes of processing and screening raw wood are omitted.

Drawings

FIG. 1 is a schematic diagram of a mechanical pulp production system using wood shavings as a feedstock in accordance with the present invention;

FIG. 2 is a flow diagram of the mechanical pulp production process of the present invention using wood shavings as a feedstock.

The reference numbers in the figures illustrate: 1. a discharging bin; 2. a reaction bin; 3. a rough grinding device; 4. a finish grinding device; 5. a first slurry tank; 6. a pressure screen; 7. a second slurry tank; 8. a belt conveyor; 9. a de-ironing separator; 10. a spraying device; 11. a stirrer; 12. tail pulp disc mill device.

Detailed Description

The present invention is further described below in conjunction with the following figures and specific examples so that those skilled in the art may better understand the present invention and practice it, but the examples are not intended to limit the present invention.

Referring to fig. 1, one embodiment of the mechanical pulp production system using wood shavings as raw material according to the present invention comprises a discharging bin for storing and feeding materials arranged in sequence; the reaction bin is used for softening fibers in the wood shavings, the reaction bin is a normal-pressure reaction device, and hot water and a reaction auxiliary agent are filled in the reaction bin; a coarse grinding device for fluffing the softened wood shavings into a fiber slurry with fiber bundles, wherein the coarse grinding device rubs the softened wood shavings to separate and free single fibers; a refining device for grinding the fiber slurry with the fiber bundles into fiber slurry in the form of individual fibers; a first stock chest for storing and stirring single fiber form stock; the pressure screen is used for screening the fiber pulp in the form of single fibers in the first pulp pond; and the second pulp tank is used for storing the screened mechanical pulp.

Specifically, the wood shavings are conveyed to the discharging bin through the belt conveyor, a small amount of ferrous metal can be doped in the wood shavings, and in order to prevent the ferrous metal from damaging the coarse grinding device and the fine grinding device, an iron remover is arranged along the conveying path of the belt conveyor during the conveying process of the belt conveyor, and the iron remover is a strong magnet and can remove the ferrous metal mixed together in the wood shavings.

Specifically, the wood shavings are thin wooden material, and its self form is comparatively loose, and inconvenient transportation to the reaction bin in this embodiment be provided with spray set above the discharge bin, spray set sprays water to the discharge bin direction, impresses the wood shavings into the discharge bin through the water spray, makes the wood shavings not be in loose, is convenient for carry to the reaction bin in.

Specifically, the reaction bin is a normal-pressure reaction device, hot water and sodium hydroxide are added into the reaction bin to serve as reaction auxiliaries, the reaction bin is used for carrying out high-temperature impregnation on the wood shavings, the wood shavings are softened, fibers in the softened wood shavings are easily kneaded and dispersed, conditions are provided for subsequent high-concentration grinding, excessive cutting of the fibers by the high-concentration grinding is avoided, the fiber strength is not affected, and a heating or heat preservation device is further arranged in the reaction bin in order to keep the high-temperature conditions in the reaction bin.

Specifically, the softened strands are passed through two grinding devices: the coarse grinding device and the fine grinding device rub the softened wood shavings to enable single fibers to be dispersed and dissociated, after the wood shavings are ground by the coarse grinding device, part of the single fibers are dispersed and dissociated, a part of the plurality of fibers are together, the fibers are not completely dispersed and dissociated to form fiber bundles, the fiber bundles are further defibered by the fine grinding device, and the fiber bundles are basically defibered by the fine-ground pulp.

Specifically, when the first pulp tank stores the pulp in the form of single fiber, the fiber tends to flocculate, and stirring is required to keep the concentration of the pulp output from the pulp tank stable, so that a stirrer is arranged in the first pulp tank and is stirred in the first pulp tank.

Specifically, the pressure sieve is the last barrier of handling the wood shavings tow, and the tow is held back through the pressure sieve, the screen cloth of pressure sieve is the slotted sieve, slotted sieve width 0.15-0.25mm, still be provided with tail thick liquid mill device between pressure sieve and the second thick liquid pond, the thick liquids through the pressure sieve screen cloth enter into the second thick liquid pond, and the thick liquids that do not pass through the pressure sieve screen cloth enter into tail thick liquid mill device, enter into the second thick liquid pond after carrying out the regrinding and defibering.

The working process of the production system of the invention is as follows:

conveying the wood shavings to a discharge bin through a belt conveyor, removing iron metal by using an iron remover in the conveying process, arranging spray water above the discharge bin to prevent the wood shavings from loosening, conveying the wood shavings to a reaction bin in a screw conveying mode, completing a softening process of the wood shavings in the reaction bin, then sequentially conveying the softened wood shavings to a coarse grinding device and a fine grinding device in a screw conveying mode for grinding, grinding the wood shavings into slurry with a single fiber form, adding dilution water in the conveying process, controlling the slurry concentration, controlling the coarse grinding concentration to be 10-20%, diluting the coarse slurry into fine grinding by the dilution water, preferably controlling the fine grinding treatment concentration to be 3-6%, conveying the slurry into a first slurry tank for storage after grinding, continuously stirring by using a stirrer in the storage process, keeping the slurry concentration output by the slurry tank stable, pumping the slurry in the first slurry tank into a pressure sieve by a slurry pump, and pressure screening is carried out to form the final mechanical pulp for production, the mechanical pulp is stored in a second pulp tank, the pulp which does not pass through the pressure screen in the screening process flows into a tail pulp disc grinding device, and the pulp enters the second pulp tank after being ground and defibered again.

Referring to fig. 2, an embodiment of the present invention of a mechanical pulp production process using wood shavings as raw materials is implemented by the above production system, and includes the following steps:

feeding and storing the wood shavings, wherein spray water is adopted to prevent the wood shavings from loosening in the feeding process;

softening internal fibers of the wood shavings, and soaking the wood shavings in hot water and a reaction auxiliary agent under a normal pressure state to soften the wood shavings;

coarsely grinding the softened wood shavings, and kneading the softened wood shavings to untwin the softened wood shavings into fiber slurry with fiber bundles;

carrying out fine grinding treatment on the fiber pulp with the fiber bundles, and grinding the fiber pulp with the fiber bundles into fiber pulp in a single fiber form;

and (3) carrying out pressure screening on the fiber pulp in the single fiber form, and screening out the mechanical pulp meeting the use requirement.

Specifically, in the step of softening the internal fibers of the wood shavings, the temperature of the hot water is maintained at 100 ℃, the reaction aid is sodium hydroxide, the concentration of the reaction aid is 10% -20%, too high a concentration makes it difficult to sufficiently contact the loose wood shavings with the liquid phase, the treatment time is 30-120min, and the longer the reaction time is, the better the fiber treatment effect is.

Specifically, in the step of pressure screening, screening is carried out by adopting a slotted screen mode, the width of the slotted screen is 0.15-0.25mm, the slurry passing through the slotted screen is mechanical slurry meeting the use requirement, and the slurry not passing through the slotted screen needs to be ground again for defibering to achieve the mechanical slurry meeting the use requirement.

The above-mentioned embodiments are merely preferred embodiments for fully illustrating the present invention, and the scope of the present invention is not limited thereto. The equivalent substitution or change made by the technical personnel in the technical field on the basis of the invention is all within the protection scope of the invention. The protection scope of the invention is subject to the claims.