Paper pulp hydrogen peroxide residue adjusting method

Abstract

The invention relates to the technical field of papermaking, in particular to a method for adjusting residual hydrogen peroxide in paper pulp, which comprises the following steps: adding 0.1-0.5 kg / bdt of hydrogen peroxide digestion agent into a pulping system, fully and uniformly mixing the hydrogen peroxide digestion agent with pulp, decomposing hydrogen peroxide into water and oxygen, and accurately adjusting and controlling the residual hydrogen peroxide by adjusting the dosage of the hydrogen peroxide digestion agent; hydrogen peroxide digesting agent adding systems are arranged at an outlet of a pulp tower and a white water tank of a paper machine for diluting the pulp for standby application, the adding amount at the outlet of the pulp tower is 0.1-0.3 kg / bdt, and the adding amount at the white water tank of the paper machine is 0.05-0.01 kg / bdt; when the pulping hydrogen peroxide residue exceeds the standard range, a hydrogen peroxide digestion agent is added to the outlet of the pulp tower and the white water tank of the paper machine, so that the hydrogen peroxide residue is rapidly reduced to the qualified range. By accurately adding the hydrogen peroxide digestion agent, the residual hydrogen peroxide is strictly controlled in a proper range so as to ensure the quality of paper products.

Description

Technical Field

[0001] The invention relates to the technical field of papermaking, and in particular to a method for adjusting hydrogen peroxide residue in pulp. Background Art

[0002] The unreacted hydrogen peroxide remaining in the pulp is called hydrogen peroxide residue, which will have a certain impact on paper products. An appropriate amount of hydrogen peroxide residue can promote the bonding between fibers, thereby improving the tensile strength and bursting strength of the paper, but too much hydrogen peroxide residue will damage the fibers, resulting in a decrease in paper strength; hydrogen peroxide residue will affect the color of the paper, and too much hydrogen peroxide may make the paper appear yellow or grayish white, commonly known as yellowing of the paper; in addition, too low hydrogen peroxide residue will lead to too low oxidation-reduction potential (ORP), affecting the use effect of paper machine fungicides. Summary of the invention

[0003] The purpose of the present invention is to provide a method for regulating the hydrogen peroxide residue in pulp in view of the defects and shortcomings of the prior art, by accurately adding a hydrogen peroxide digester, strictly controlling the hydrogen peroxide residue within an appropriate range to ensure the quality of paper products.

[0004] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: it comprises the following operation method: adding 0.1-0.5kg / bdt of hydrogen peroxide dissolving agent into the pulping system, and mixing it with the pulp fully and evenly, decomposing the hydrogen peroxide into water and oxygen, and realizing accurate control of the hydrogen peroxide residue by adjusting the dosage of the hydrogen peroxide dissolving agent; setting a hydrogen peroxide dissolving agent adding system at the pulp tower outlet and the paper machine white water tank for pulp dilution, the adding amount at the pulp tower outlet is 0.1-0.3kg / bdt, and the adding amount at the paper machine white water tank is 0.05-0.01kg / bdt; when the hydrogen peroxide residue in the pulp exceeds the standard range, the hydrogen peroxide residue is rapidly reduced to the qualified range by adding the hydrogen peroxide dissolving agent at the pulp tower outlet and the paper machine white water tank.

[0005] Furthermore, the hydrogen peroxide digester is added by remote control.

[0006] Furthermore, a remote addition control system for hydrogen peroxide digester is arranged on the top of the medium-consistency pump of the pressing screw in the pulping system, and the electrical signal of the hydrogen peroxide digester dosing pump is connected to the DCS screen to realize remote addition control of hydrogen peroxide digester addition.

[0007] Furthermore, an abnormal alarm system is set at the top of the medium-consistency pump of the pressing screw in the pulping system; when the dosing pump has an abnormality (the flow rate exceeds the set value by 15%), the standby pump is automatically started / stopped to ensure that the added amount is stable and controllable; the added amount of hydrogen peroxide digester is accurately measured by the flow meter to achieve continuous and stable addition of the hydrogen peroxide digester.

[0008] Compared with the prior art, the present invention has the following beneficial effects: the present invention provides a method for regulating hydrogen peroxide residue in pulp, by accurately adding hydrogen peroxide digester, the hydrogen peroxide residue is strictly controlled within an appropriate range to ensure the quality of paper products. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a flow chart of the present invention.

[0010] Figure 2 This is a data table of the residual digestion experiment of spiral pressed hydrogen peroxide in the embodiment.

[0011] Figure 3 This is a data table of the residual digestion experiment of hydrogen peroxide in the 5# medium-concentration pump in the embodiment.

[0012] Figure 4 It is a data table of the amount of chemical added, the amount of hydrogen peroxide digester added, the residual amount of hydrogen peroxide and the pH value of the present invention. DETAILED DESCRIPTION

[0013] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. The preferred embodiments in the description are only used as examples, and all other embodiments obtained by those skilled in the art without making any creative work are within the scope of protection of the present invention.

[0014] like Figure 1-Figure 4 As shown, this specific implementation adopts the following technical scheme: it includes the following operation method: a remote addition control system of hydrogen peroxide digester is set on the top of the 5# medium-consistency pump after the 1# screw press and the 2# screw press are connected in parallel in the pulping system, and the electrical signal of the hydrogen peroxide digester dosing pump is connected to the DCS screen to realize the remote addition control of the hydrogen peroxide digester; a hydrogen peroxide digester addition system is set at the outlet of the pulp tower (card pulp tower and paper pulp tower) and the white water tank of the paper machine for pulp dilution, and the addition amount at the pulp tower outlet is 0.1-0.3kg / bdt, and the addition amount at the white water tank of the paper machine is 0.05-0.01kg / bdt; when the hydrogen peroxide residue in the pulp exceeds the standard range, the hydrogen peroxide residue is quickly reduced to the qualified range by adding hydrogen peroxide digester at the outlet of the pulp tower and the white water tank of the paper machine;

[0015] And an abnormal alarm system is set on the top of the 5# medium-concentration pump; when the dosing pump has an abnormality (the flow rate exceeds the set value by 15%), the standby pump is automatically started / stopped to ensure that the addition amount is stable and controllable; the addition amount of hydrogen peroxide digester is accurately measured by the flow meter to achieve continuous and stable addition of hydrogen peroxide digester.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. It can realize accurate control of hydrogen peroxide residue, avoiding fungicide failure and paper diseases such as yellow spots caused by fluctuations in hydrogen peroxide residue.

[0018] 2. Controllable pulp index of chemical mechanical pulp system process: residual hydrogen peroxide in the squeezing screw medium-concentration pump is 100-200ppm.

[0019] 3. The residual hydrogen peroxide in pulping can be controlled at 10-60 mg / L.

[0020] For those skilled in the art, they can modify the technical solutions recorded in the aforementioned embodiments and make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for adjusting the residual hydrogen peroxide in pulp, characterized in that: It includes the following operating method: adding 0.1-0.5kg / bdt of hydrogen peroxide digester into the pulping system, and fully and evenly mixing it with the pulp to decompose the hydrogen peroxide into water and oxygen, and by adjusting the dosage of the hydrogen peroxide digester, accurate control of the hydrogen peroxide residue is achieved.

2. A method for adjusting hydrogen peroxide residue in pulp according to claim 1, characterized in that: A hydrogen peroxide digester adding system is installed at the pulp tower outlet and the paper machine white water tank for pulp dilution. The addition amount at the pulp tower outlet is 0.1-0.3kg / bdt, and the addition amount at the paper machine white water tank is 0.05-0.01kg / bdt. When the hydrogen peroxide residue in the pulp exceeds the standard range, the hydrogen peroxide digester is added at the pulp tower outlet and the paper machine white water tank to quickly reduce the hydrogen peroxide residue to the acceptable range.

3. A method for adjusting hydrogen peroxide residue in pulp according to claim 2, characterized in that: The hydrogen peroxide digester is added by remote control.

4. A method for adjusting hydrogen peroxide residue in pulp according to claim 3, characterized in that: A remote addition control system for hydrogen peroxide digester is arranged on the top of the medium-consistency pump of the pressing screw in the pulping system, and the electrical signal of the hydrogen peroxide digester dosing pump is connected to the DCS screen to realize remote addition control of hydrogen peroxide digester.

5. A method for adjusting hydrogen peroxide residue in pulp according to claim 4, characterized in that: An abnormal alarm system is set on the top of the medium-consistency pump of the pressing screw in the pulping system; when the dosing pump has an abnormality, the standby pump is automatically started / stopped to ensure that the addition amount is stable and controllable; the addition amount of hydrogen peroxide digester is accurately measured by the flow meter to achieve continuous and stable addition of hydrogen peroxide digester.

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