阅读说明：本技术 一种漂白木质纤维素的生产系统及其生产方法 (Production system and production method of bleached lignocellulose ) 是由 张楠 于 2019-11-22 设计创作，主要内容包括：本发明提供一种漂白木质纤维素的生产系统,包括脉冲除尘器、以及依次连接的圆筒筛、反应釜、粉碎机、混合机、气流干燥机、分离器、木粉机、风筛、包装秤；所述分离器包括相连接的第一分离器和第二分离器,所述第一分离器的进料端与气流干燥机的出料端连接,所述第一分离器和第二分离器的出料端均与木粉机的进料端连接；所述第二分离器、风筛和包装秤的粉尘输出端与脉冲除尘器的输入端连接,所述脉冲除尘器的输出端和风筛的物料筛余输出口均与木粉机的进料端连接；所述混合机连接有漂白药剂加药装置。本发明还提供一种漂白木质纤维素的生产方法。本发明具有连续生产、生产效率高、经济环保的特点,而且生产制备工艺简单,成本低,实用性强。(The invention provides a production system for bleaching lignocellulose, which comprises a pulse dust collector, a cylindrical sieve, a reaction kettle, a pulverizer, a mixer, an air flow dryer, a separator, a wood powder machine, an air screen and a packing scale, wherein the cylindrical sieve, the reaction kettle, the pulverizer, the mixer, the air flow dryer, the separator, the wood powder machine, the air screen and the packing scale are sequentially connected; the separator comprises a first separator and a second separator which are connected, the feeding end of the first separator is connected with the discharging end of the airflow dryer, and the discharging ends of the first separator and the second separator are connected with the feeding end of the wood flour machine; the dust output ends of the second separator, the air screen and the packing scale are connected with the input end of the pulse dust collector, and the output end of the pulse dust collector and the material screening output end of the air screen are connected with the feed end of the wood powder machine; the mixing machine is connected with a bleaching agent dosing device. The invention also provides a production method of the bleached lignocellulose. The invention has the characteristics of continuous production, high production efficiency, economy and environmental protection, and has simple production and preparation process, low cost and strong practicability.)

1. A production system for bleaching lignocellulose is characterized by comprising a pulse dust collector (8), a cylindrical sieve (1), a reaction kettle (2), a pulverizer (3), a mixer (4), an air flow dryer (5), a separator, a wood flour machine (10), an air screen (11) and a packing scale (12), wherein the cylindrical sieve, the reaction kettle (2), the pulverizer (3), the mixer, the air flow dryer (5), the separator, the wood flour machine and the packing scale are sequentially connected; the separator comprises a first separator (6) and a second separator (7) which are connected, the feeding end of the first separator (6) is connected with the discharging end of the airflow dryer (5), and the discharging ends of the first separator (6) and the second separator (7) are connected with the feeding end of the wood flour machine (10); the dust output ends of the second separator (7), the air screen (11) and the packing scale (12) are connected with the input end of the pulse dust collector (8), and the output end of the pulse dust collector (8) and the material screening output end of the air screen (11) are connected with the feed end of the wood powder machine (10); the mixer (4) is connected with a bleaching agent dosing device (14).

2. The bleached lignocellulose production system according to claim 1, wherein the bleaching agent in the bleaching agent dosing device (14) is pumped into the mixer (4) by a lift pump (15).

3. The bleached lignocellulose production system according to claim 1, wherein high-temperature and high-pressure steam is introduced into the reaction kettle (2) and the air flow dryer (5).

4. The bleached lignocellulose production system according to claim 1, wherein the cylindrical screen (1) is connected at its feed end with a feeder (13).

5. A bleached lignocellulose production system according to claim 1, wherein a fan (9) is connected to the pulse precipitator (8).

6. A production method of bleached lignocellulose is characterized by comprising the following steps:

firstly, selecting processing byproducts of fresh logs as raw materials, and putting the raw materials into a cylindrical screen (1) through a feeding machine (13) to remove barks and tree scars;

secondly, steaming the raw materials after impurity removal in a reaction kettle (2) filled with high-temperature high-pressure steam, wherein the temperature in the reaction kettle (2) is 150-;

coarsely crushing the heat-treated raw materials in a crusher (3), wherein the granularity of the coarsely crushed raw materials is 60 meshes;

step four, spraying bleaching solution onto the coarsely crushed raw materials in the mixer (4), stirring the raw materials simultaneously, and continuing stirring for 30-60min after spraying is finished; the bleaching solution is prepared by dissolving hydrogen peroxide and a bleaching assistant in an alkaline aqueous solution with the pH value of 9-13, the mole ratio of the bleaching assistant to the hydrogen peroxide is 1:2, and the bleaching solution contains 3-15% of hydrogen peroxide;

fifthly, feeding the bleached material into an airflow dryer (5) to be dried until the moisture is 10-15%;

collecting the dried materials through a first separator (6) and a second separator (7), and then feeding the collected materials into a wood powder machine (10) for grinding;

step seven, the ground materials enter an air screen (11) for screening;

and step eight, the screened qualified materials enter a packing scale (12) to be packed into finished products.

7. The method for producing bleached lignocellulose according to claim 6, wherein the raw material is a processing by-product of poplar.

8. The method for producing bleached lignocellulose according to claim 6, wherein the moisture content of the raw material in the first step is 20-50%, and the moisture content of the raw material after spraying in the fourth step is controlled to be 25-40%.

9. The method for producing bleached lignocellulose according to claim 6, wherein the alkaline aqueous solution is a mixed solution of any one or more of a sodium carbonate aqueous solution, a sodium hydroxide aqueous solution, and a sodium metasilicate aqueous solution.

10. The method for producing bleached lignocellulose according to claim 6, wherein the bleaching aid is tetraacetylethylenediamine or sodium p-nonanoyloxybenzenesulfonate.

Technical Field

The invention relates to the field of special-shaped bolts, in particular to a production system and a production method for bleached lignocellulose.

Background

Lignocellulose is an organic fibrous substance obtained by chemical treatment and mechanical processing of natural renewable wood. Natural lignocelluloses are mostly the inherent color of wood and are limited in certain fields of application. Bleached lignocellulose is more widely used.

Traditional lignocellulosic bleaching processes are similar to pulping processes, require large amounts of water, and have severe blowdown. Dry bleaching is an innovative process that can bleach materials with minimal water, while producing no pollution emissions. The method should be widely used for producing the lignocellulose filler for the synthetic leather.

The general dry bleaching modes in the industry at present are discontinuous and need to be connected manually; drying is generally carried out in a drying mode, and the occupied area is large; the drying time is long, and the productivity is low; the air-drying easily causes the dust in the production workshop to be large, seriously influences the working environment of production personnel and causes great environmental pollution.

Patent CN103351546B discloses an additive for artificial leather products and a preparation method thereof, which comprises crushed branches, hydrogen peroxide accounting for 5-15% of the total weight of the crushed branches, ultramarine blue accounting for 0.05-1%, glass water accounting for 3-13%, a whitening agent accounting for 0.5-3%, flake caustic soda accounting for 0.5-2% and sodium sulfide accounting for 1-5% of the total weight of the crushed branches. The finished product is obtained by stirring, airing, grinding, powder sieving, quality inspection, sterilization and bagging. The method has the disadvantages that the bleaching effect is poor, whitening agent needs to be added additionally to improve whiteness, and the subsequent milling temperature is too high (200 ℃), so that the product is easy to discolor.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a production system and a production method for bleached lignocellulose, the production system and the production method have the characteristics of continuous production, high production efficiency, economy and environmental protection, thoroughly change the traditional production environment for bleached lignocellulose, reduce environmental pollution, and have the advantages of simple production and preparation process, guaranteed quality, low cost and strong practicability.

According to one aspect of the invention, a production system for bleaching lignocellulose is provided, which comprises a pulse dust collector (8), a cylindrical sieve (1), a reaction kettle (2), a pulverizer (3), a mixer (4), an air flow dryer (5), a separator, a wood powder machine (10), an air screen (11) and a packing scale (12), wherein the cylindrical sieve, the reaction kettle (2), the pulverizer (3), the mixer, the air flow dryer and the packing scale are connected in sequence; the separator comprises a first separator (6) and a second separator (7) which are connected, the feeding end of the first separator (6) is connected with the discharging end of the airflow dryer (5), and the discharging ends of the first separator (6) and the second separator (7) are connected with the feeding end of the wood flour machine (10); the dust output ends of the second separator (7), the air screen (11) and the packing scale (12) are connected with the input end of the pulse dust collector (8), and the output end of the pulse dust collector (8) and the material screening output end of the air screen (11) are connected with the feed end of the wood powder machine (10); the mixer (4) is connected with a bleaching agent dosing device (14). And dust generated in the second separator, the air screen and the packing scale is collected by the pulse dust collector, and dust materials collected in the pulse dust collector and materials sieved by the air screen can return to the wood flour machine for secondary grinding. The devices are connected through the conveying pipeline, the device is directly and automatically conveyed to the next device after the previous device completes corresponding operation, production is continuous, and the devices do not need to be taken out for manual operation, such as direct drying in an airflow dryer and no taking out for airing.

Preferably, the bleaching agent in the bleaching agent adding device (14) is pumped into the mixer (4) through a lifting pump (15).

Preferably, high-temperature and high-pressure steam is introduced into the reaction kettle (2) and the airflow dryer (5).

Preferably, the feeding end of the cylindrical screen (1) is connected with a feeding machine (13), and raw materials are thrown into the cylindrical screen (1) through the feeding machine (13) to remove impurities.

Preferably, the pulse dust collector (8) is connected with a fan (9).

In order to achieve the above object, the present invention also provides a method for producing bleached lignocellulose, comprising the steps of:

firstly, selecting processing byproducts of fresh logs as raw materials, and putting the raw materials into a cylindrical screen (1) through a feeding machine (13) to remove barks and tree scars;

secondly, steaming the raw materials after impurity removal in a reaction kettle (2) filled with high-temperature high-pressure steam, wherein the temperature in the reaction kettle (2) is 150-;

coarsely crushing the raw materials after heat treatment in a crusher (3), wherein the granularity of the coarsely crushed raw materials is 60 meshes, so that the granularity of the raw materials meets the next production requirement;

step four, spraying bleaching solution onto the coarsely crushed raw materials in the mixer (4), stirring the raw materials simultaneously, and continuing stirring for 30-60min after spraying is finished; the bleaching solution is prepared by dissolving hydrogen peroxide and a bleaching assistant in an alkaline aqueous solution with the pH value of 9-13, the mole ratio of the bleaching assistant to the hydrogen peroxide is 1:2, and the bleaching solution contains 3-15% of hydrogen peroxide; the coarsely crushed raw materials are dried and bleached in a mixer, and a bleaching agent is pumped into the mixer by a lift pump to be mixed and reacted with the raw materials;

fifthly, feeding the bleached material into an airflow dryer (5) to be dried until the moisture is 10-15%;

collecting the dried materials through a first separator (6) and a second separator (7), and then feeding the collected materials into a wood powder machine (10) for grinding;

step seven, the ground materials enter an air screen (11) for screening;

and step eight, the screened qualified materials enter a packing scale (12) to be packed into finished products.

Preferably, the raw material is a processing byproduct of poplar, and the processing byproduct of log is used as the raw material, so that the raw material is wide in source and low in cost.

Preferably, the water content of the raw material in the first step is 20-50%, and the water content of the raw material after spraying in the fourth step is controlled to be 25-40%.

Preferably, the alkaline aqueous solution is a mixed solution of one or more of a sodium carbonate aqueous solution, a sodium hydroxide aqueous solution and a sodium metasilicate aqueous solution.

Preferably, the bleaching assistant is tetraacetylethylenediamine or sodium p-nonanoyloxybenzenesulfonate.

Compared with the prior art, the invention has the following beneficial effects:

(1) the production system and the production method of the bleached lignocellulose can bleach substances under the condition of a very small amount of water, do not discharge pollution, have the characteristics of continuous production, high production efficiency, economy and environmental protection, thoroughly change the traditional production environment of the bleached lignocellulose and reduce environmental pollution;

(2) the production system and the production method of the bleached lignocellulose, which are provided by the invention, have the advantages that the production is continuous, the manual connection is not needed, the device does not need to be taken out for manual operation, the device can be directly dried in an airflow dryer, the device does not need to be taken out for airing, the drying is simple and quick, and the problems of large occupied area, long drying time, low capacity, large dust and the like of the traditional airing mode are solved;

(3) according to the production system and the production method of the bleached lignocellulose, the raw materials are subjected to impurity removal, heat treatment, coarse crushing, dry bleaching, drying, fine grinding and screening treatment sequentially through the production system to prepare the bleached lignocellulose, so that the production system is efficient, pollution-free, environment-friendly and low in cost;

(4) the invention relates to a production system and a production method of bleached lignocellulose.A reaction kettle is arranged to ensure that after the raw materials are subjected to heat treatment, lignin is partially degraded under the action of water and heat to generate lignin fragments; meanwhile, after the easily degradable substances such as the hemicellulose and the like are degraded, the activated and degraded lignin is exposed outside, so that the bleaching agent is more fully contacted with the lignin and is easier to bleach during subsequent bleaching;

(5) the production system and the production method of the bleached lignocellulose have the advantages of simple system, ingenious design and obvious effect;

(6) the production system and the production method of the bleached lignocellulose use the log processing by-products as raw materials, and have wide sources and low price;

(7) the production system and the production method of the bleached lignocellulose adopt the low-temperature bleaching assistant and hydrogen peroxide to generate the peroxyacid with stronger oxidation capacity for bleaching, the reaction is mild, the whiteness of the product is improved, the good whitening effect can be achieved without adding a whitening agent, the production system and the production method are environment-friendly and safe, and the product can not be discolored;

(8) the production system and the production method of the bleached lignocellulose, which are provided by the invention, have the advantages of simple production and preparation process, guaranteed quality, low cost and strong practicability, and are suitable for large-scale popularization.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a schematic connection diagram of a bleached lignocellulose production system;

FIG. 2 is a schematic diagram showing a portion of a bleached lignocellulose production system;

FIG. 3 is a schematic diagram of a second embodiment of a bleached lignocellulose production system;

FIG. 4 is a schematic diagram of a portion of a bleached lignocellulose production system;

in FIGS. 1-4: 1 is a cylinder screen, 2 is a reaction kettle, 3 is a pulverizer, 4 is a mixer, 5 is an air flow dryer, 6 is a first separator, 7 is a second separator, 8 is a pulse dust collector, 9 is a fan, 10 is a wood powder machine, 11 is an air screen, 12 is a packaging scale, 13 is a feeding machine, 14 is a bleaching agent dosing device, and 15 is a lifting pump.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.