JP2006144148A - Method for accelerating separation of impurity in waste paper pulp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a chemical preparation to take effects well by enabling a pulp to be continuously dehydrated to about 30% pulp concentration without difficulty, and to enable a strong ink, an ash content or the like to be removed. <P>SOLUTION: The method for accelerating the separation of impurities in the waste paper pulp comprises cleaning and concentrating a disaggregated pulp so as to have about 6-7% concentration by a cooking pot 11, dehydrating the resultant pulp to about 20% concentration by a net-type dehydrator 13 of a first-step dehydration step, dehydrating the resultant pulp to about 30% concentration by a screw-type dehydrator 14 of a second-step dehydrating step, kneading the dehydrated pulp by adding the chemical preparation by a kneader 15, and aging the kneaded pulp in an aging tower 16. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for promoting impurity separation of waste paper pulp, which efficiently promotes the separation of impurities in the waste paper pulp processing step.

  In the field of used paper recycling treatment in recent years, the condition of used paper used for recycling has become worse due to the diversification of paper and ink, and it is difficult to remove highly adherent ink, and it is a coat of surface treatment agent. The amount of ash content and difficulty in increasing the whiteness is a big problem when paper is made from waste paper.

  In other words, in order to make waste paper as a raw material, it is difficult to produce clean paper unless strong ink and ash that are problematic are removed.

  Waste paper is disaggregated by the method of melting by adding water and chemicals and steaming at a high temperature, or the method of melting the used waste paper by a rotating blade. After that, debris is removed and dewatered by a drum with a wire mesh or wire slit, sent to a kneader or disperser by a conveyor, where it is kneaded and stored in an aging tower, or left dehydrated. Aged in the aging tower.

  After the disaggregation, recently, as shown in FIG. 2, after being washed or concentrated by a concentration washing machine 1 such as an extract, a disk extract or a suction filter washer, a network such as a vacuum filter, a twin thickener, a cylinder press, or a double wire is used. The ink is dehydrated by the system dehydrator 2 and then sent to the kneader 3 by the conveyor, where the ink particles are peeled off and removed, followed by aging by the aging tower 4 to increase the whiteness. However, the aging tower 4 may be placed immediately after the net-type dehydrator 2.

  However, if the net-type dehydrator 2 is only dewatered in and out of a concentration of 20%, the kneading effect is small because the pulp concentration is low. Therefore, mechanical separation and removal of ink or the like is difficult, and the chemicals to be added have a low adsorption rate to the disaggregated pulp. If a large amount of chemicals are not added, there is no effect, and a large amount of chemicals is required.

  The object of the present invention is to solve the above-mentioned problems, sufficiently dewatering waste paper pulp, ensuring a kneading effect, saving chemicals used, and enabling removal of strong ink and the like. It is to provide a method for promoting impurity separation of pulp.

  The technical feature of the method for promoting impurity separation of waste paper pulp according to the present invention for achieving the above object is that after the disaggregated pulp is concentrated to a concentration of about 6 to 7% in the concentration process, the concentration is 20% by a low concentration dehydrator. A first-stage dewatering process that dehydrates inside and outside, a second-stage dewatering process that dehydrates to a concentration of about 30% with a high-concentration dehydrator, and chemicals that are added to the pulp dehydrated in the second-stage dewatering process. There is a chemical reaction treatment step for performing a reaction treatment and an aging step for aging the pulp.

  According to the method for promoting impurity separation of waste paper pulp according to the present invention, waste paper pulp is dehydrated to a certain degree by the first stage dewatering step, and further dehydrated by the high concentration dehydrator in the second stage dewatering step. Highly dehydrated pulp can be obtained accurately and the pulp concentration can be remarkably increased, and a great kneading effect can be expected.

The present invention will be described in detail based on the embodiments shown in the drawings.
FIG. 1 shows an embodiment of an impurity separation promoting method applied to the waste paper pulp processing step of the present invention. The used paper is cooked in the steaming pot 11, and the sludge disintegrated pulp is washed or concentrated, and the pulp 12 removes large debris etc., and the concentration, that is, the water content is concentrated by about 6 to 7%. This is sent to the network dehydrator 13 in the first stage dewatering process.

  The net-type dehydrator 13 comprises a vacuum filter, twin thickener, cylinder press, double wire, etc., dehydrates the concentrated pulp to about 20%, removes hardware and small debris with a screen, and performs the second stage dewatering process with a conveyor. Send to screw dehydrator 14.

  The screw-type dehydrator 14 comprises a screw press, and further increases the previous dehydration of about 20% to 30% and sends it to a kneader (disperser) 15. The kneader 15 kneads the dehydrated pulp by adding chemicals to about 30%, peels off and removes impurities such as highly adhesive ink and ash, and sends them to the next aging tower 16. In the aging tower 16, the kneaded pulp is continuously ripened, and chemicals such as sodium hypochlorite are added to increase the whiteness, which is sent to the next process.

  By going through these steps, it is possible to greatly promote the peeling effect of strong ink, ash, etc., greatly improve the removal of impurities, and there is little moisture in the pulp even when processing with chemicals added Therefore, the rate of chemical adsorption to the pulp is increased, the effectiveness of the chemical is improved, the reaction time of the chemical is increased, the amount used can be saved, and the economic efficiency can be improved.

  In addition, the ash and the like in the pulp can be easily removed, and no washing water is required, so that the burden on the drainage can be reduced.

  In addition, a concentration washer is disposed in front of the net-type dehydrator 13 in the first stage dewatering step, and the concentration or concentration is about 6 to 7%. Even if it has a concentration, there is no hindrance to the concentration, and even if the screw-type dehydrator 14 is used in the second stage dewatering process, the dewatering yield is not adversely affected.

  In addition, since the screw-type dehydrator 14 having high mechanical strength is used in the second stage dewatering step, there is no mechanical problem even if the dewatering degree is about 30%. Even if the degree is 30%, normal maintenance is sufficient, and the maintenance cost of the machine does not increase.

It is a block diagram of an Example. It is process drawing of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Steamer 12 Pulpa 13 Net system dehydrator of the 1st stage dehydration process 14 Screw system dehydrator of the 2nd stage dehydration process 15 Kneader 16 Aging tower

Claims (2)

  After the disintegrated pulp is concentrated to a concentration of about 6 to 7% in the concentration process, it is dewatered to a concentration of about 30% by a high concentration dehydrator, and a first stage dewatering step of dehydrating to a concentration of about 20% with a low concentration dehydrator. A second-stage dehydration step, a chemical reaction treatment step in which a chemical is added to the pulp dehydrated in the second-stage dehydration step, and a ripening step for aging the pulp. A method for promoting the separation of impurities in waste paper pulp.   The method for promoting impurity separation of waste paper pulp according to claim 1, wherein a screw press is used in the second stage dewatering step.

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