阅读说明：本技术 用于磷酸法活性炭生产中木屑的高效处理方法 (Efficient treatment method for sawdust in production of phosphoric acid method activated carbon ) 是由 周建斌 张书 王亮才 马欢欢 周建明 陈登宇 章一蒙 于 2020-06-28 设计创作，主要内容包括：本发明提出的是一种用于磷酸法活性炭生产中木屑的高效处理方法,具体包括如下步骤：1)初筛：采用初级筛将木屑中含有的大粒径的木屑筛除；2)除砂：采用除砂器将木屑中的泥沙杂物分离；3)晾干：将除砂后的木屑自然堆放晾干；4)烘干：将晾干后的木屑烘干；5)次筛：通过次级筛再次筛取一定粒径范围的烘干木屑；6)浸渍搅拌：将经过次筛的烘干木屑与一定波美度的磷酸浸渍搅拌。本发明自动化程度高,节能高效,利于后期工艺装置稳定运行,减少检修次数；木屑除砂彻底,有效降低灰分,进一步提高活性炭品质,增强实用性；工艺操作简单,易于推广,降低生产成本,能够带来显著的经济效益。(The invention provides a high-efficiency treatment method for sawdust in phosphoric acid method activated carbon production, which specifically comprises the following steps: 1) primary screening: screening out the wood chips with large particle sizes contained in the wood chips by adopting a primary screen; 2) sand removal: separating silt and impurities in the wood chips by using a sand remover; 3) drying: naturally stacking and airing the sand-removed sawdust; 4) drying: drying the dried sawdust; 5) secondary screening: sieving the dried sawdust with a secondary sieve again in a certain particle size range; 6) dipping and stirring: and (3) dipping and stirring the dried sawdust subjected to secondary screening and phosphoric acid with a certain Baume degree. The invention has high automation degree, energy conservation and high efficiency, is beneficial to the stable operation of the later process device and reduces the maintenance times; the sawdust is thoroughly degritted, the ash content is effectively reduced, the quality of the activated carbon is further improved, and the practicability is enhanced; the process is simple to operate, easy to popularize, low in production cost and capable of bringing remarkable economic benefits.)

1. The high-efficiency treatment method for the sawdust in the production of the phosphoric acid method activated carbon is characterized by comprising the following steps:

1) primary screening: screening out the wood chips with large particle sizes contained in the wood chips by adopting a primary screen;

2) sand removal: separating silt and impurities in the wood chips by using a sand remover;

3) drying: naturally stacking and airing the sand-removed sawdust;

4) drying: drying the dried sawdust;

5) secondary screening: sieving the dried sawdust with a secondary sieve again in a certain particle size range;

6) dipping and stirring: and (3) dipping and stirring the dried sawdust subjected to secondary screening and phosphoric acid with a certain Baume degree.

2. The method for efficiently treating the sawdust in the production of activated carbon by a phosphoric acid method according to claim 1, wherein the primary screen in the step 1) is cylindrical, the size of the aperture of the screen is 2-3 cm, the rotating speed is 20-25 r/min, and an acute angle of 5-10 degrees is formed between the primary screen and the horizontal plane; the material with larger grain size screened out by the primary screen is conveyed to a boiler through a second conveyor belt and is combusted together with the rice hull gasification gas to supply heat to the wood dust drying process in the step 4); the wood chips after primary screening continue to enter the desanding procedure in the step 2).

3. The method as claimed in claim 1, wherein the desander used in the phosphoric acid method activated carbon production comprises a primary desander and a secondary desander, the primarily screened sawdust is conveyed to the upper part of the primary desander through a conveyor belt, and then sequentially passes through the primary desander and the secondary desander, and then falls into a drying chamber for natural drying.

4. The method for efficiently treating the sawdust in the production of the phosphoric acid method activated carbon according to claim 1, wherein the temperature of hot air flow in the airflow drying device in the step 4) is 100-120 ℃, and the moisture content of discharged materials is 20-25%.

5. The method as claimed in claim 1, wherein the secondary screen in step 5) is cylindrical and comprises two screens, wherein the first screen has a diameter of 0.280-0.355 mm, the second screen has a diameter of 1cm, the first screen and the second screen rotate coaxially at an acute angle of 5-10 ° with respect to the horizontal plane at a rotation speed of 20-25 r/min.

6. After the dried sawdust passes through the first screen, undersize sawdust with the particle size smaller than 0.280-0.355 mm is screened out, after the rest sawdust passes through the second screen, oversize sawdust with the particle size larger than 1cm is screened out, the undersize sawdust and the oversize sawdust are conveyed to a boiler together, and the undersize sawdust and the oversize sawdust are combusted together with the rice husk gasification gas to supply heat for the dried sawdust process in the step 4).

7. The method for the high efficiency treatment of the wood chips in the phosphoric acid method activated carbon production according to any one of claims 1 to 5, characterized in that the method uses a wood chip treatment device, the structure of which comprises: the device comprises a first conveyor belt, a primary screen, a second conveyor belt, a third conveyor belt, a primary desander, a secondary desander, a fourth conveyor belt, an air flow drying device and a secondary screen; the end of the first conveyor belt is arranged in the primary screen, the end of the primary screen is arranged above the second conveyor belt, the bottom of the primary screen is arranged above the third conveyor belt, the end of the third conveyor belt is arranged above the first-stage desander, the lower reaches of the first-stage desander are provided with the second-stage desander, the second-stage desander is arranged in the drying chamber, the dried wood dust in the drying chamber is conveyed into the airflow drying device through the fourth conveyor belt, the airflow drying device is connected with the secondary screen, a second discharge port at the bottom of the secondary screen is connected with the bin, and a discharge port of the bin is arranged above the stirrer.

Technical Field

The invention relates to a high-efficiency treatment method for sawdust in phosphoric acid method activated carbon production, and belongs to the technical field of activated carbon production processes.

Background

The active carbon has huge specific surface area and developed pore structure, so that the active carbon has extremely strong adsorption performance, and simultaneously has extremely stable chemical and physical properties, is not dissolved in strong acid or strong base under general conditions, and can still keep good stability and adsorption performance in acid and alkaline environments, so that the active carbon is an excellent adsorbent which has no mature substitute in many fields (military industry, gas and water treatment and the like) so far, is widely applied to procedures of decolorization, refining, odor removal, purification and the like of military industry, fermentation, biological pharmacy industry, synthetic industry, environmental protection industry and the like, and the purification treatment process adopting the active carbon has the advantages of good effect, quick action, simple and convenient operation, no side effect, low price and the like. Compared with the activated carbon prepared by a physical method, the activated carbon prepared by a phosphoric acid method has developed medium and large pores, and is mainly used for liquid phase purification and purification processes. In the production process of the phosphoric acid method activated carbon, phosphoric acid is mainly used as an activating agent to promote the processes of infiltration, dehydration, hydrolysis, aromatization and the like, and has a crosslinking effect with saccharide molecules.

In traditional phosphoric acid method active carbon production process, the saw-dust is mixed with phosphoric acid solution promptly and is activated after simple screening, does not have processes such as prescreening, degritting, stoving and secondary sieve, consequently has many defects in actual production process: (1) maintenance frequency of subsequent instruments and equipment is high, and the service life of the instruments is shortened (for example, the moisture content of sawdust is very uneven, a pipeline is easy to block, sand is easy to block a rotary furnace and wear the instruments and equipment); (2) the particle size of the activated material is not uniform, the recovery is not thorough, the moisture is not easy to control in the drying process, and the like, so that a lot of inconvenience is brought to enterprise production; (3) the quality of the activated carbon product is unstable (an important process for controlling the quality of the activated carbon during activation is the water content of sawdust, and if the water content is too high, phosphoric acid is not easily decomposed into pyrophosphoric acid, so that the iodine adsorption value, the methylene blue decolorization rate and the caramel decolorization rate of the activated carbon are reduced); (4) the ash content of the activated carbon is higher, and the quality is reduced (the sand in the sawdust causes the finished product of the activated carbon to also contain the sand, so the ash content of the activated carbon is higher, and the iodine adsorption value, the methylene blue decolorization rate and the caramel decolorization rate of the activated carbon are reduced).

Disclosure of Invention

The invention aims to overcome the defects of the existing phosphoric acid method activated carbon production process, and particularly provides an efficient treatment method for sawdust in the phosphoric acid method activated carbon production aiming at the sawdust treatment and screening process, so that thorough desanding is realized, and the stable operation of process devices is ensured, thereby achieving the win-win effect of further improving the economic benefit and the activated carbon quality.

The technical solution of the invention is as follows: the high-efficiency treatment method for the wood chips in the production of the phosphoric acid method activated carbon specifically comprises the following steps:

1) primary screening: screening out large-particle-size sawdust contained in sawdust by using a primary screen, wherein the primary screen is cylindrical, the size of the aperture of a screen mesh of the primary screen is 2-3 cm, the rotating speed is 20-25 r/min, and an acute angle of 5-10 degrees is formed between the primary screen and the horizontal plane; the material with larger grain size screened out by the primary screen is conveyed to a boiler through a second conveyor belt and is combusted together with the rice hull gasification gas to supply heat to the wood dust drying process in the step 4); the wood chips after primary screening continue to enter the desanding procedure in the step 2).

2) Sand removal: separating silt and impurities in the wood chips by using a sand remover; the sand remover comprises a primary sand remover and a secondary sand remover, wood chips subjected to primary screening are conveyed to the upper part of the primary sand remover through a conveying belt, sequentially pass through the primary sand remover and the secondary sand remover, and fall into a drying chamber to be naturally dried.

3) Drying: naturally stacking and airing the sand-removed sawdust;

4) drying: and (3) feeding the dried sawdust into an airflow drying device for drying, wherein the temperature of hot airflow in the airflow drying device is 100-120 ℃, and the water content of discharged materials is 20-25%.

5) Secondary screening: sieving the dried sawdust with a secondary sieve again in a certain particle size range; the secondary screen is cylindrical and comprises two screens, wherein the aperture size of the first screen is 0.280-0.355 mm, the aperture size of the second screen is 1cm, the first screen and the second screen rotate coaxially, the rotating speed is 20-25 r/min, and an acute angle of 5-10 degrees is formed between the first screen and the horizontal plane. After the dried sawdust passes through the first screen, undersize sawdust with the particle size smaller than 0.280-0.355 mm is screened out, after the rest sawdust passes through the second screen, oversize sawdust with the particle size larger than 1cm is screened out, the undersize sawdust and the oversize sawdust are conveyed to a boiler together, and the undersize sawdust and the oversize sawdust are combusted together with the rice husk gasification gas to supply heat for the dried sawdust process in the step 4).

6) Dipping and stirring: and (3) dipping and stirring the dried sawdust subjected to secondary screening and phosphoric acid with a certain Baume degree.

The sawdust treatment device adopted by the method structurally comprises a first conveyor belt, a primary screen, a second conveyor belt, a third conveyor belt, a primary desander, a secondary desander, a fourth conveyor belt, an air flow drying device and a secondary screen; the end of the first conveyor belt is arranged in the primary screen, the end of the primary screen is arranged above the second conveyor belt, the bottom of the primary screen is arranged above the third conveyor belt, the end of the third conveyor belt is arranged above the first-stage desander, the lower reaches of the first-stage desander are provided with the second-stage desander, the second-stage desander is arranged in the drying chamber, the dried wood dust in the drying chamber is conveyed into the airflow drying device through the fourth conveyor belt, the airflow drying device is connected with the secondary screen, a second discharge port at the bottom of the secondary screen is connected with the bin, and a discharge port of the bin is arranged above the stirrer.

Compared with the prior art, the invention has the advantages that:

1) the automation degree is high, energy is saved, the efficiency is high, the stable operation of the later process device is facilitated, and the maintenance times are reduced;

2) the sawdust is thoroughly degritted, the ash content is effectively reduced, the quality of the activated carbon is further improved, and the practicability is enhanced;

3) the process is simple to operate, easy to popularize, low in production cost and capable of bringing remarkable economic benefits.

Drawings

FIG. 1 is a flow chart of the method for efficiently treating wood chips in the production of phosphoric acid method activated carbon.

Detailed Description

The technical scheme of the invention is described in the following with the accompanying drawings of the specification. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention. The technical scheme of the invention is carried out on the basis of the existing phosphoric acid method activated carbon, and the rest steps of the production process of the activated carbon adopting the method are carried out according to the existing flow of the conventional phosphoric acid method activated carbon.

The high-efficiency treatment method for the wood chips in the production of the phosphoric acid method activated carbon shown in the figure 1 specifically comprises the following steps:

1) primary screening: screening out the wood chips with large particle sizes contained in the wood chips by adopting a primary screen;

2) Sand removal: separating silt and impurities in the wood chips by using a sand remover;

3) drying: naturally stacking and airing the sand-removed sawdust;

4) drying: drying the dried sawdust;

5) secondary screening: sieving the dried sawdust with a secondary sieve again in a certain particle size range;

6) dipping and stirring: and (3) dipping and stirring the dried sawdust subjected to secondary screening and phosphoric acid with a certain Baume degree.

The primary screen in the step 1) is cylindrical, the aperture size of a screen mesh of the primary screen is 2-3 cm, the rotating speed is 20-25 r/min, and an acute angle of 5-10 degrees is formed between the primary screen and the horizontal plane. The material with larger grain size screened out by the primary screen is conveyed to a boiler through a second conveyor belt and is combusted together with the rice hull gasification gas to supply heat to the wood dust drying process in the step 4); the wood chips after primary screening continue to enter the desanding procedure in the step 2).

The desander in step 2) include one-level desander and second grade desander, the saw-dust through the primary screening passes through the conveyer belt and delivers to one-level desander top, loops through one-level desander and second grade desander, falls into the room that dries and dries naturally.

And in the step 3), the dried sawdust is sent into an airflow drying device and dried at the temperature of 100-120 ℃.

The temperature of hot air flow in the air flow drying device in the step 4) is 100-120 ℃, and the water content of discharged materials is 20-25%.

The secondary screen in the step 5) is cylindrical and comprises two screens, wherein the aperture size of the first screen is 0.280-0.355 mm, the aperture size of the second screen is 1cm, the first screen and the second screen rotate coaxially, the rotating speed is 20-25 r/min, and an acute angle of 5-10 degrees is formed between the first screen and the horizontal plane. After the dried sawdust passes through the first screen, undersize sawdust with the particle size smaller than 0.280-0.355 mm is screened out, after the rest sawdust passes through the second screen, oversize sawdust with the particle size larger than 1cm is screened out, the undersize sawdust and the oversize sawdust are conveyed to a boiler together, and the undersize sawdust and the oversize sawdust are combusted together with the rice husk gasification gas to supply heat for the dried sawdust process in the step 4).

The structure of the sawdust processing device adopted by the method comprises: the device comprises a first conveyor belt, a primary screen, a second conveyor belt, a third conveyor belt, a primary desander, a secondary desander, a fourth conveyor belt, an air flow drying device and a secondary screen; the end of the first conveyor belt is arranged in the primary screen, the end of the primary screen is arranged above the second conveyor belt, the bottom of the primary screen is arranged above the third conveyor belt, the end of the third conveyor belt is arranged above the first-stage desander, the lower reaches of the first-stage desander are provided with the second-stage desander, the second-stage desander is arranged in the drying chamber, the dried wood dust in the drying chamber is conveyed into the airflow drying device through the fourth conveyor belt, the airflow drying device is connected with the secondary screen, a second discharge port at the bottom of the secondary screen is connected with the bin, and a discharge port of the bin is arranged above the stirrer.

The specific working process of the device is as follows:

1) firstly, conveying sawdust into a primary screen by a first conveyor belt, enabling sawdust with the particle size larger than 2-3 cm to fall to a second conveyor belt at the tail end of the primary screen at the rotating speed of 20-25 r/min, conveying the sawdust into a boiler by the second conveyor belt to be combusted with rice hull gasification gas for heat supply, and enabling the sawdust with the particle size smaller than 2-3 cm to fall onto a third conveyor belt from the lower end of the primary screen;

2) conveying the sawdust with the particle size of less than 2-3 cm into a primary desander by a third conveyor belt to complete primary desanding, then completing secondary desanding by a secondary desander, naturally airing the sawdust subjected to secondary desanding in an airing chamber, conveying the sawdust into an airflow drying device by a fourth conveyor belt, and drying at the temperature of hot airflow of 100-120 ℃;

3) the dried sawdust has the water content of 20-25%, the dried sawdust passes through a secondary screen, undersize sawdust with the particle size smaller than 0.280-0.355 mm is removed through a first screen, the rest sawdust passes through a second screen, oversized sawdust with the particle size larger than 1cm is removed, the sawdust with the proper size obtained through final screening is conveyed to a storage bin through a pipeline, and then the sawdust and phosphoric acid are soaked and stirred for preparing activated carbon; and the screened undersize wood chips and oversize wood chips are sent to the boiler again for combustion and heat supply.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the contents of the specification and the drawings, or applied to other related technical fields directly or indirectly, are included in the scope of the present invention.