CN1267762A - Mechanical grass plants (wheat straw cornstalk, rice straw & Chinese silvergrass stalk) pulping technology - Google Patents

Abstract

In the present invention, the material is cut in cutting machine, soaked in soaking tank with 0.8-1.2% concentration NaOH solution at 50-80 deg.c and pulped, and pulp is concentrated, milled and separated in centrifugal sieve. The pulping process has no digestion step and uses water repeatedly so that it is power saving and water saving and has low pulping cost.

Description

Gramineae plant (wheat straw, cornstalk, straw, awns bar) mechanical pulping process

The present invention relates to a kind of gramineae plant (wheat straw, cornstalk, straw, awns bar) mechanical pulping process.

Now pulping process is complicated as wheat straw chemical pulping, semichemical pulping technology in the paper industry, but its raw material passes through slurrying again behind the chemical steaming more, slurrying cost height, and environmental pollution is serious, and power consumption is big, and the water consumption is greatly.

The object of the present invention is to provide that a kind of slurrying cost is low, energy consumption is little, waste water returns and recycles, free of contamination gramineae plant (wheat straw, cornstalk, straw, awns bar) mechanical pulping process.

The objective of the invention is to finish like this: raw material places dipping-steaming pool through grass transmitting machine, chaffcutter chopping, be condensed into underflow through concentrating the extruder extruding again, underflow enters 1# mill defibrination after preheating, intelligent feeding, slurry enters 2# mill defibrination through screw feed again, after this moment slurry being placed the rare wet adjusting pH value of stock tank, separate through screen centrifuge, screened stock is sent into paper machine and is copied paper, and thick slurry is sent into 1# and ground defibrination once more.

Come the present invention done below in conjunction with drawings and Examples and describe in further detail:

Accompanying drawing 1 is a process chart of the present invention.

With reference to accompanying drawing, gramineae plant of the present invention (wheat straw, cornstalk, straw, awns bar) mechanical pulping process, its raw material is through grass transmitting machine, chaffcutter chopping, place in the dipping-steaming pool of NaOH concentration 0.8--1.2%, temperature is 50--80 ℃ of immersion, raw material after soaking is sent into its concentration of stock pump slurrying 3--5%, slurry is sent into again and concentrated extruder and concentrate that to make the concentration of slurry be 35--40%, extruding back waste water returns dipping-steaming pool and recycles.It is 70--90 ℃ that the slurry of concentration 35--40% is sent in the preheating machine through the steam preheating temperature, it is 15--20SR that slurry after the preheating is sent into its pulp concentration of 1# mill defibrination through intelligent feeding, the slurry that with concentration is 15--20SR is sent into 2# mill defibrination through screw feed, making its pulp concentration is 20--35SR, again slurry is placed rare wet and adjusting pH value in the stock tank, making its concentration is 5--7%, pH value 7--9, this moment slurry is sent into screen centrifuge through stock pump and is separated, screened stock after the separation enters the screened stock pond, send into paper machine through stock pump and copy paper, isolated thick slurry is sent into 1# mill defibrination again, even grinds qualified screened stock.

It copies paper cost low (corrugated paper) as the generated by making paper with wheat straws cost 900 yuan per ton with the slurrying of this technology, 610 yuan of cornstalk papermaking per ton costs, and save a large amount of waters, the corrugated paper of producing is measured the above standard of national B level that reaches fully through check, the waste water of discharging is pollution-free, meets national discharge of wastewater 1--2 grade standard.This technology need not waft marrow, dust removal process.

Gramineae plant provided by the invention (wheat straw, cornstalk, straw, awns bar) mechanical pulping process, the slurrying cost is low, and draining is pollution-free, and energy consumption is low, energy savings, and solved the problem of utilizing of northern country wheat straw, cornstalk.

The applicable all kinds of paper industries of this technology use, and are specially adapted to middle-size and small-size paper mill and use.

Claims (1)

1, a kind of gramineae plant (wheat straw, cornstalk, straw, the awns bar) mechanical pulping process, its technical characterictic is: with raw material through grass transmitting machine, the chaffcutter chopping,---1.2% dipping-steaming pool in temperature 50---the 80 ℃ of immersions that place NaOH concentration 0.8, raw material after soaking is sent into its concentration 3 of stock pump slurrying---5%, again slurry is sent into and is concentrated the concentrated concentration 35 that makes slurry of extruder---40%, waste water after the extruding returns dipping-steaming pool,---it is 70 through the steam preheating temperature that 40% slurry is sent into preheating machine interior---90 ℃ with concentration 35, it is 15 that slurry after the preheating is sent into its pulp concentration of 1# mill defibrination through intelligent feeding---20SR, with concentration is 15---the slurry of 20SR is sent into 2# mill defibrination through screw feed, making its pulp concentration is 20---35SR, slurry is placed rare wet its concentration 5 in the stock tank---7%, pH value 7---9, slurry is sent into screen centrifuge through stock pump and is separated, screened stock after the separation enters the screened stock pond, copy paper through being pumped into paper machine, isolated thick slurry is sent into 1# mill defibrination again.

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