CN110093812A - A kind of wet strength agent adding system for reducing wet strength agent deposit and entering - Google Patents

Abstract

The invention relates to a wet strength agent adding system for reducing the entry of wet strength agent deposits, comprising a wet strength agent storage tank, a valve, a pump and a check valve on the outlet pipeline, a water source, a valve on the outlet pipeline, and a wet strength agent. The outlet pipes of the strong agent storage tank are merged and communicated with the adding point of the wet strength agent through the conveying pipe. The filter installed on the conveying pipe has a built-in filter mesh with a filter diameter of 50-80 mesh. Compared with the prior art, the invention effectively prevents deposits from entering, and also has the advantage of being convenient for flushing.

Description

A wet strength agent addition system that reduces the entry of wet strength agent deposits

technical field

The invention relates to the field of papermaking, in particular to a wet strength agent adding system which reduces the entry of wet strength agent deposits.

Background technique

Generally, after the paper is completely soaked by water, it almost completely loses its strength. It can only retain 2-7% of its original dry paper strength. The strength of paper in the wet state is called wet strength, and wet strength refers to dryness Even after the finished paper is completely soaked or saturated by water, it can still maintain a certain strength. For example, military map paper and marine paper can still maintain their original integrity, clarity, deformation and due strength after rain or water immersion; Banknote paper can still have good folding resistance and friction resistance after being impregnated by water and sweat. The paper used in these special cases requires a certain wet strength. The wet strength is obtained only by paper sizing and Surface coating is difficult to achieve. In the paper industry, certain chemical additives must be used to meet the requirements for wet strength. These chemicals are generally referred to as wet strength agents. The addition of wet strength agents can make the paper even after drying. It can also maintain 20-50% of the original dry strength under long-term immersion in water or water solvent.

Tissue paper has low weight, low dry strength, and correspondingly low wet strength, but in order for people to use it, the paper is not easy to be damaged, especially facial tissue, which often needs to wipe wet body parts, and a wet strength agent must be added. . Wet strength agents are mainly thermosetting resins, generally including urea-formaldehyde resin (UF), melamine-formaldehyde resin (MF) and polyamide epoxy resin (PAE). Tissue paper generally uses polyamide epoxy resin wet strength agent because of its high requirements for safety and environmental protection.

Because the wet strength agent is a resin agent with high viscosity, it needs to be diluted when used. The raw liquid of the wet strength agent is pumped and mixed with dilution water. The water source requires a pressure of 4-8bar. The wet strength agent after mixing and dilution is added to The specified add point. Resin agents have the characteristics of adhesion on the pipe due to their high viscosity. As time goes by, the wet strength agent deposits on the inner wall of the pipe will accumulate more and more. At first, it will adhere to the official road, and then accumulate too much Under the scouring of the pipeline water flow, a part of the surface layer will start to peel off. At the same time, a part of the water flow will deposit and adhere. In this way, the sediment will continue to peel off and adhere again, and the sediment will continue to enter the papermaking system.

The existing wet strength agent adding system in the paper mill does not have any measures to prevent deposits from entering the system. It can only be improved by cleaning at a fixed period, and the cleaning needs to be shut down, and it cannot be guaranteed to be completely cleaned. The most important effect of the material entry system is to produce sticky macula on the paper surface, which makes the two layers of paper stick together and affects the quality of the paper produced.

Contents of the invention

The object of the present invention is to provide a wet strength agent adding system that can effectively prevent deposits from entering and facilitate flushing in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions:

A wet strength agent addition system that reduces the ingress of wet strength agent deposits, comprising

Wet strength agent storage tank, the outlet pipeline is equipped with valves, pumps and check valves,

The water source is provided with a valve on the outlet pipe, which merges with the outlet pipe of the wet strength agent storage tank and communicates with the wet strength agent addition point through the delivery pipe.

It also includes a filter set on the delivery pipeline, which has a built-in filter screen with a filter diameter of 50-80 mesh to ensure that the sediment can be filtered out and the wet strength agent can pass through smoothly.

The filters include

Inlet provided in the upper part,

The filter screen connected inside is supported by the fixing frame,

The outlet provided at the lower part,

Exhaust valves on top and bottom.

Valves are provided at the inlet and outlet.

The inlet and outlet of the filter are also connected by a bypass pipeline, and the bypass pipeline is provided with a bypass valve. When cleaning or replacing the filter screen, the bypass valve is opened, and the valves of the filter inlet and outlet are closed. Clean or replace the filter screen. After completion, open the valves at both ends of the filter, close the bypass valve, and let the filter work again.

The delivery pipeline is also provided with an external discharge bypass pipeline close to the adding point of the wet strength agent, and an external discharge bypass valve is provided on the external discharge bypass pipeline. An opening and closing valve is provided on the conveying pipeline between the external discharge bypass pipeline and the wet strength agent addition point. Use this for in-line flushing. When it is necessary to flush the entire pipeline, close the opening and closing valve entering the wet strength agent addition point, and open the external discharge bypass valve. At this time, according to the situation of different manufacturers, if the pressure of the water source can be adjusted, the water pressure should be increased as much as possible. , to increase the intensity of flushing, to flush the pipeline, and the flushed water is discharged through the external discharge bypass valve, and does not enter the interior of the system. Usually, this cleaning can be completed within five minutes. After the flushing is completed, switch the valve. Restore normal wet strength agent supply. Such a short flushing time can avoid the waste of shutting down and flushing pipelines.

Compared with the prior art, the present invention has the following advantages:

(1) In the original design, there is only one pipeline valve at the position of entering the adding point. If the pipeline is flushed, the pipeline joint must be disassembled. Generally, there is not enough time to do it online. After the improvement, an external discharge valve is added, and the valve can be completed simply by switching the valve. Cleaning saves time.

(2) The improved design adds a filter, which can effectively prevent or reduce sediment from entering the system and affect the quality of the paper produced.

(3) The filter is equipped with a bypass valve. When cleaning or replacing the filter screen, there is no need to stop the addition of the wet strength agent, which makes the addition of the wet strength agent more stable.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Figure 2 is a schematic diagram of the structure of the filter used.

In the figure, 1-wet strength agent storage tank, 2-water source, 3-one-way valve, 4-filter, 5-bypass pipe, 6-bypass valve, 7-exhaust bypass pipe, 8-outside Bypass valve, 9-wet strength agent addition point, 10-opening and closing valve, 41-opening fixing bolt, 42-top exhaust valve, 43-fixing frame, 44-inlet, 45-outlet, 46-filter, 47 - Bottom exhaust valve.

Detailed ways

The present invention will be described in detail below in conjunction with specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

Example

A wet strength agent addition system that reduces the entry of wet strength agent deposits. Its structure is shown in Figure 1, including a wet strength agent storage tank 1, a valve, a pump, and a one-way valve 3 are arranged on the outlet pipeline, and a water source 2 is exported. The pipeline is provided with a valve, which merges with the outlet pipeline of the wet strength agent storage tank and communicates with the wet strength agent adding point 9 through the delivery pipeline. A filter 4 is also arranged on the delivery pipeline to ensure that the wet strength agent can pass through smoothly while the sediment can be filtered out. The structure of the filter 4 is shown in Figure 2, including the inlet 44 arranged on the top, the filter screen 46 connected to the inside through the support of the fixed frame 43, the outlet 45 arranged on the bottom, and the top exhaust valve 42 arranged on the top and bottom And bottom exhaust valve 47. The filter screen 46 used in the present embodiment is a filter screen with a filter diameter of 50-80 mesh, and the filtering effect is the best. In addition, the top of the filter is provided with an opening fixing bolt 41, which is convenient for opening and closing the filter to replace the filter screen.

The inlet and outlet of the filter 4 are also connected by a bypass pipe 5, and the bypass pipe 5 is provided with a bypass valve 6. When the filter screen needs to be cleaned or replaced, the bypass valve 6 is opened and the inlet and outlet of the filter are closed. Valve, the filter screen is cleaned or replaced, after completion, open the valves at both ends of the filter, close the bypass valve 6, and allow the filter to work again.

The delivery pipeline is also provided with an external discharge bypass pipeline 7 near the wet strength agent addition point 9, and an external discharge bypass valve 8 is provided on the external discharge bypass pipeline 7. An opening and closing valve 10 is provided on the conveying pipeline between the effluent bypass pipeline 7 and the wet strength agent addition point 9 . Use this for in-line flushing. When it is necessary to flush the entire pipeline, close the on-off valve 10 entering the wet strength agent addition point 9, and open the external discharge bypass valve 8. At this time, according to the situation of different manufacturers, if the pressure of the water source can be adjusted, increase the pressure as much as possible. High water pressure increases the intensity of flushing to flush the pipeline, and the flushed water is discharged through the external discharge bypass valve 8 and does not enter the interior of the system. Usually, this cleaning can be completed within five minutes. After the flushing is completed , switch the valve and restore the normal supply of wet strength agent. Such a short flushing time can avoid the waste of shutting down and flushing pipelines.

The present invention adds two improvements on the original basis: one is to add an online flushing system. When the original pipeline needs to be flushed, the pipeline needs to be disassembled and must be shut down for processing. However, the improved design only needs to switch the valve. Complete; the second is to increase the pipeline filtration system, which can effectively prevent sediment from entering the system.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims (7)

1. A wet strength agent addition system that reduces the entry of wet strength agent deposits, comprising Wet strength agent storage tank, the outlet pipeline is equipped with valves, pumps and check valves, The water source is provided with a valve on the outlet pipe, which merges with the outlet pipe of the wet strength agent storage tank and communicates with the wet strength agent addition point through the delivery pipe. It is characterized in that it also includes a filter arranged on the delivery pipeline, and the filter has a built-in filter screen with a filter diameter of 50-80 mesh. 2. A wet strength agent addition system that reduces the entry of wet strength agent deposits according to claim 1, wherein the filter includes Inlet provided in the upper part, The filter screen connected inside is supported by the fixing frame, The outlet provided at the lower part, Exhaust valves on top and bottom. 3. A wet strength agent adding system for reducing the entry of wet strength agent deposits according to claim 2, characterized in that valves are provided at the inlet and outlet. 4. A wet strength agent adding system for reducing the entry of wet strength agent deposits according to claim 2, characterized in that the inlet and outlet of the filter are also connected through a bypass pipe, and the bypass pipe is With bypass valve. 5. A wet strength agent addition system that reduces the entry of wet strength agent deposits according to claim 1, characterized in that, the delivery pipeline is also provided with an external bypass line near the point where the wet strength agent is added . 6 . The wet strength agent adding system for reducing the entry of wet strength agent deposits according to claim 5 , characterized in that, the outlet bypass pipeline is provided with an outlet bypass valve. 7 . 7. A wet strength agent addition system that reduces the entry of wet strength agent deposits according to claim 5, characterized in that, the delivery pipeline between the efflux bypass pipeline and the addition point of the wet strength agent Equipped with on-off valve.