WO2017063305A1

WO2017063305A1 - Process for circulating and recycling white water in paper machine

Info

Publication number: WO2017063305A1
Application number: PCT/CN2016/000558
Authority: WO
Inventors: 腾铁生; 张跃平
Original assignee: 新疆国力源投资有限公司
Priority date: 2015-10-13
Filing date: 2016-10-10
Publication date: 2017-04-20
Also published as: CN105239438A; CN105239438B

Abstract

A process for circulating and recycling white water in a paper machine. Collected white water in a paper machine is divided into two portions after being filtered by a microfiltration machine, one portion is directly used for washing forming wires, and the other portion is re-filtered after flocculation and sedimentation to become clean water which is used for washing felt. The process solves the recycling problem of white water in a paper machine. Moreover, by collecting water after flocculation, the yield of paper pulp is improved, and the closed circulatory of white water in the paper machine is ensured.

Description

Paper machine white water circulation recycling process

Technical field

The invention relates to a new process for white water treatment of a paper machine.

Background technique

It is well known that the use of water in the papermaking process can not be recycled, can achieve the goal of zero emissions, largely depends on whether the white water of the paper machine can be closed. In the past, paper mills used white water in paper mills. Some paper mills used multiple discs to filter, and a small amount of water was used for washing nets. The wool cloth could not be washed. A large amount of water still had to be returned to the middle water treatment; most paper mills used white water. Direct access to the mid-stage water treatment system is both a waste and an increase in operating costs for water treatment. The main reason why the paper machine white water cannot be recycled is that the simply treated water cannot be used to clean the felt.

Summary of the invention

The technical problem to be solved by the present invention is to overcome the existing defects and provide a new process for completely solving the problem of reuse of white water of a paper machine.

The object of the present invention is specifically achieved by the following technical solutions:

A paper machine white water recycling process, after collecting the white water of the paper machine filtered by a microfilter, divided into two parts, a part is directly used for cleaning the forming net, a part is flocculated and precipitated, and then filtered to form clean water for cleaning. Felt.

As a preferred solution, the above process includes the following steps:

1) The collected paper machine white water is sent to a cylindrical microfiltration machine for filtration, and the fine fibers are recovered, and the filtered water is stored in the collection tank;

2) Part of the water in the collection tank is used directly for cleaning the forming wire, and as a water for the equipment sealing system (for the 90-mesh polyester mesh of the forming wire, the microfiltration machine (the microfiltration machine is a cylindrical woolen mesh filter) There is no problem with the subsequent water cleaning);

3) Another part of the collection pool is first flocculated and precipitated, then passed through a super filter (for Kadant Johnson) The PETAXTM fine filtration system provided by the company is filtered and stored in a clean water tank for use as high and low pressure water for cleaning felts;

4) The collected floc is transported to the flow delivery system together with the recovered fine fibers, which improves the pulp yield and ensures the closed cycle of the white water of the paper machine.

Preferably, in the step 1), the mesh of the micro rate machine filter is 150-200 mesh.

Preferably, in the step 3), the flocculating agent is an inorganic flocculating agent.

Further preferably, the flocculating agent is modified diatomaceous earth. The manufacturer is Baishan Liwei Diatomite Comprehensive Products Co., Ltd., product name: modified diatomaceous earth water purifying agent.

Further preferably, the modified diatomaceous earth has a mesh number of 300-350 mesh.

Further preferably, 0.6 kg is used for purifying 1 ton of water.

Preferably, in the step 3), the super filter is a PETAXTM fine filter produced by Kadant Company.

The beneficial effects of the invention:

The process of the invention is used to completely solve the problem of reuse of the white water of the paper machine, and the water collected after the flocculation improves the pulp yield and ensures the closed cycle of the white water of the paper machine. Compared with the prior art, the main advantages are as follows:

1. The process flow is short, and it is not necessary to return to the middle water treatment system to save operating expenses.

2, the floor space is small, the system can be built in the papermaking workshop, saving one-time investment.

3, reached a closed cycle, pointing out the direction for zero discharge of paper.

detailed description

The preferred embodiments of the present invention are described in the following, and the preferred embodiments described herein are intended to illustrate and explain the invention.

Example 1

A paper machine white water recycling process comprises the following steps:

1. The collected paper machine white water is sent to a cylindrical microfiltration machine for filtration to recover fine fibers, and the filtered water is stored in the collection tank. The micro rate machine filter mesh number is 150-200 mesh.

2. Part of the water in the collection tank is used directly for cleaning the forming wire, and the equipment is sealed with water. Since the forming net is a 90-mesh polyester net, there is no problem in water washing after filtering with a microfilter.

3. Another part of the water in the collection tank is flocculated and precipitated, then filtered by a super filter and stored in a clear water tank for cleaning the high and low pressure water of the felt. The flocculant is an inorganic flocculant (modified diatomaceous earth) in an amount of 0.06% and a mesh number of 300-350 mesh. The super filter is a PETAXTM fine filter manufactured by Kadant.

4. The collected floc is transported to the flow delivery system together with the recovered fine fibers, which improves the pulp yield and ensures the closed cycle of the white water of the paper machine.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still The technical solutions described are modified, or some of the technical features are equivalently replaced. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

The utility model relates to a white water circulation recycling process of a paper machine, which is characterized in that: after collecting, the white water of the paper machine is filtered by a microfilter, and is divided into two parts, a part is directly used for cleaning the forming net, a part is flocculated and precipitated, and then filtered to form clean water. Used to clean the felt.
The paper machine white water recycling process according to claim 1, comprising the steps of:

1) The collected paper machine white water is sent to a cylindrical microfiltration machine for filtration, and the fine fibers are recovered, and the filtered water is stored in the collection tank;

2) A portion of the water in the collection tank is used directly for cleaning the forming wire and as a water for the equipment sealing system;

3) Another part of the water in the collection pool is flocculated and precipitated, then filtered by a super filter and stored in a clean water tank for use as high and low pressure water for cleaning the felt;

4) The collected flocs are delivered to the flow delivery system along with the recovered fine fibers.
The paper machine white water recycling process according to claim 1, wherein in the step 1), the mesh of the micro rate machine filter is 150-200 mesh.
The paper machine white water circulation recycling process according to claim 1, wherein in the step 3), the flocculating agent is an inorganic flocculant.
The paper machine white water circulation recycling process according to claim 4, wherein the flocculating agent is modified diatomaceous earth.
The paper machine white water recycling process according to claim 5, wherein the modified diatomaceous earth has a mesh number of 300-350 mesh.
A white water recycling process for a paper machine according to any one of claims 1 or 4 to 6, characterized in that 0.6 kg is used for purifying one ton of water.
The papermaking machine of claim 1 white water circulation recovery process as claimed in claim, wherein: said step 3), the filter is a super Kadant PETAX TM produced a fine filter.