Chemical mechanical pulping method for recycling of wet strength waste paper

Abstract

The invention discloses a chemical mechanical pulping method for recycling of wet strength waste paper. The method comprises a material preparation section, a steaming section, a first squeezing dipping chemical mechanical treatment section, a second squeezing dipping chemical mechanical treatment section, a latency and re-defibering section and a purification, screening and concentration section. According to the method, wet strength waste paper fiber dissociation and re-pulping are realized while the original pulp strength is not reduced under the action of mechanical strength and chemical treatment; furthermore, at the two squeezing dipping chemical mechanical treatment sections in series connection, a wet strength agent in the waste paper can be oxidized under the acidic condition firstly, and then hydrolysis is further promoted under the alkaline condition, so that the chemical bonding among molecules of the wet strength agent and between the wet strength agent and pulp fibers are destroyed more effectively, and the fiber dissociation rate and the re-pulping yield are effectively increased. The problems that the wet strength waste paper recycling, pulping and dissociation rate is low and the strength is substantially reduced are solved, and continuous, large-scale, low-water-consumption, low-energy-consumption, pollution-free and environment-friendly pulping can be realized.

Description

technical field

[0001] The invention relates to a pulping system and a pulping method, in particular to a waste paper recovery and reuse chemical mechanical pulping system and pulping method. Background technique

[0002] Waste paper is an important fiber raw material for papermaking. All countries attach great importance to the recycling of waste paper resources. The world's waste paper recycling volume increased from 182.6 million tons in 2005 to 223.4 million tons in 2010; the recovery rate increased from 49.8% to 56.6%. , developed countries generally exceed 60%, and South Korea and Germany exceed 80%. my country's waste paper pulping increased from 28.1 million tons in 2005 to 53.05 million tons in 2010, and its proportion in the total pulp consumption increased from 54.0% to 62.7%, of which domestic waste paper pulp increased from 27.8% to 38.0%. During the "Twelfth Five-Year Plan" period, the increase in waste paper pulp is about 14 million tons. The domestic waste ...

Examples

Embodiment 1

[0073] Example 1: Bleaching paper machine breaks and scraps containing wet strength agents, repulping and recycling

[0074] Broken paper and leftovers are conveyed by the chain conveyor to the hydropulper and shredded into paper pieces, then sent to the drum washing machine 4 to adjust the concentration to 3% for washing and slag removal, and then pumped by the material pump 5 to The oblique spiral dehydrator 6 dehydrates and concentrates, and then transports it to the steaming chamber 7 for steaming for 15 minutes. The steam pressure is 0.3MPa. According to the weight percentage of the absolute dry raw material, when entering the steaming chamber, spray 0.1% rewetting agent; after steaming, the tablet is sent to the first twin-screw impregnation machine 9 by the third screw conveyor 8, extruded and kneaded into a silk ball and concentrated to about 35% concentration, and then according to the weight of the absolute dry raw material Percentage, add 1% liquid NaOH and appro...

Embodiment 2

[0076] Example 2: Unbleached paper machine broke and scrap repulping recycling with wet strength agent

[0077] Broken paper and leftovers are transported by the chain conveyor to the hydraulic pulper and shredded into paper pieces, and then transported to the drum washing machine 4 to adjust the concentration to 4% for washing and slag removal, and then pumped by the material pump 5 to the inclined Spiral dehydrator 6 is dehydrated and concentrated, and then transported to the steam chamber 7 for steaming for 25 minutes. The steam pressure is 0.45MPa. According to the weight percentage of the absolute dry raw material, when transported to the steam chamber, spray 0.12% rewetting agent; after steaming, the tablet is sent to the first twin-screw impregnation machine 9 by the third screw conveyor 8, extruded and kneaded into a silk ball and concentrated to about 40% concentration, and then according to the weight of the absolute dry raw material Percentage, 1.2% H added by met...

Embodiment 3

[0079] Example 3: Repulping of unbleached waste paper and waste carton board containing wet strength agents

[0080]The waste paper and waste cardboard are conveyed by the chain-plate conveyor to the shredder and shredded into paper pieces, and sent to the drum washing machine 4 to adjust the concentration to 5% for washing and slag removal, and then pumped by the material pump 5 Dehydration and concentration in the oblique spiral dehydrator 6, and then transported to the steaming chamber 7 for steaming for 30 minutes, the steam pressure is 0.6 MPa, according to the weight percentage of the dry raw material, when transported to the steaming chamber, it is sprayed into the steaming chamber at the feed port. 0.15% rewetting agent; after steaming, the flakes are sent to the first twin-screw impregnation machine 9 by the third screw conveyor 8, extruded and kneaded into silk balls and concentrated to about 45% concentration, and then according to the absolute dry raw material % ...

technical field

[0001] The invention relates to a pulping system and a pulping method, in particular to a waste paper recovery and reuse chemical mechanical pulping system and pulping method. Background technique

[0002] Waste paper is an important fiber raw material for papermaking. All countries attach great importance to the recycling of waste paper resources. The world's waste paper recycling volume increased from 182.6 million tons in 2005 to 223.4 million tons in 2010; the recovery rate increased from 49.8% to 56.6%. , developed countries generally exceed 60%, and South Korea and Germany exceed 80%. my country's waste paper pulping increased from 28.1 million tons in 2005 to 53.05 million tons in 2010, and its proportion in the total pulp consumption increased from 54.0% to 62.7%, of which domestic waste paper pulp increased from 27.8% to 38.0%. During the "Twelfth Five-Year Plan" period, the increase in waste paper pulp is about 14 million tons. The domestic waste ...

Examples

Embodiment 1

[0073] Example 1: Bleaching paper machine breaks and scraps containing wet strength agents, repulping and recycling

[0074] Broken paper and leftovers are conveyed by the chain conveyor to the hydropulper and shredded into paper pieces, then sent to the drum washing machine 4 to adjust the concentration to 3% for washing and slag removal, and then pumped by the material pump 5 to The oblique spiral dehydrator 6 dehydrates and concentrates, and then transports it to the steaming chamber 7 for steaming for 15 minutes. The steam pressure is 0.3MPa. According to the weight percentage of the absolute dry raw material, when entering the steaming chamber, spray 0.1% rewetting agent; after steaming, the tablet is sent to the first twin-screw impregnation machine 9 by the third screw conveyor 8, extruded and kneaded into a silk ball and concentrated to about 35% concentration, and then according to the weight of the absolute dry raw material Percentage, add 1% liquid NaOH and appro...

Embodiment 2

[0076] Example 2: Unbleached paper machine broke and scrap repulping recycling with wet strength agent

[0077] Broken paper and leftovers are transported by the chain conveyor to the hydraulic pulper and shredded into paper pieces, and then transported to the drum washing machine 4 to adjust the concentration to 4% for washing and slag removal, and then pumped by the material pump 5 to the inclined Spiral dehydrator 6 is dehydrated and concentrated, and then transported to the steam chamber 7 for steaming for 25 minutes. The steam pressure is 0.45MPa. According to the weight percentage of the absolute dry raw material, when transported to the steam chamber, spray 0.12% rewetting agent; after steaming, the tablet is sent to the first twin-screw impregnation machine 9 by the third screw conveyor 8, extruded and kneaded into a silk ball and concentrated to about 40% concentration, and then according to the weight of the absolute dry raw material Percentage, 1.2% H added by met...

Embodiment 3

[0079] Example 3: Repulping of unbleached waste paper and waste carton board containing wet strength agents

[0080]The waste paper and waste cardboard are conveyed by the chain-plate conveyor to the shredder and shredded into paper pieces, and sent to the drum washing machine 4 to adjust the concentration to 5% for washing and slag removal, and then pumped by the material pump 5 Dehydration and concentration in the oblique spiral dehydrator 6, and then transported to the steaming chamber 7 for steaming for 30 minutes, the steam pressure is 0.6 MPa, according to the weight percentage of the dry raw material, when transported to the steaming chamber, it is sprayed into the steaming chamber at the feed port. 0.15% rewetting agent; after steaming, the flakes are sent to the first twin-screw impregnation machine 9 by the third screw conveyor 8, extruded and kneaded into silk balls and concentrated to about 45% concentration, and then according to the absolute dry raw material % ...

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