JP2003253583A - Scale-attaching device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scale-attaching device for knowing the attaching situation of scale in a circulation system of paper-making process water quickly and accurately for setting the kind and adding concentration of water-treating chemicals added to the system for suppressing the generation of the scale, quickly and accurately. <P>SOLUTION: This scale-attaching device is arranged at a part of the circulation system of the paper-making process water, and consists of a container member having an inlet port for flowing in the paper-making process water to its inside and a discharging port discharging the paper-making process water flown in from the inlet port at an upper part than that of the inlet port, agitating blades driven for rotating in the vicinity of the inlet port for agitating the paper-making process water flowing in from the inlet port into the container member and a net arranged in the vicinity of the discharging port and capable of depositing and attaching scale components in the paper-making process water on the surface of it by making a contact with the paper-making process water. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scale adhering device, and more particularly, to setting a kind and an addition concentration of a chemical that suppresses the generation of scale in a circulation system of papermaking process, when the scale component in the system is set. The present invention relates to a scale adhering device for monitoring an adhering condition and setting a chemical to be added to the system.

[0002]

2. Description of the Related Art In paper and pulp factories, kraft pulp and other papermaking fibers (pulp fibers) are produced by cooking wood chips, which are raw materials, in a cooking liquor containing caustic soda and sodium sulfide at high temperatures. As a result, lignin contained in wood is eluted and pulped to produce a papermaking fiber. At this time, calcium ions are eluted from the wood chips and react with carbonate ions in the cooking liquor to produce calcium carbonate. The generated calcium carbonate may be deposited in the circulating water system of the paper manufacturing process and adhere to the digester and the subsequent pipes to form scale. In the circulating water system of the paper manufacturing process, if scales adhere to the strainer part, problems such as a decrease in thermal efficiency and uneven pulp quality occur, which is a major obstacle to operation.

Therefore, various scale inhibitors such as polyphosphates, acrylic acid polymers and various phosphonic acids have been conventionally added to circulating water systems such as papermaking processes. When setting the type and addition concentration of scale inhibitor to be added,
A water quality analysis of papermaking process water or a bypass test for knowing the scale adhesion state is performed, and then a scale inhibitor is added according to the result.

[0004]

In checking the control state such as the water quality analysis described above, it is possible to know the calcium scale component and its amount contained in the papermaking process water in a relatively short time. However, since the quality of water in the circulating water system in the papermaking process tends to fluctuate, it cannot be said that the obtained analysis results accurately reflect the condition of the water system. It could only be used as a guide for determining whether or not to prevent. Although the bypass test is a direct method, the monitoring period is a long period of about 7 to 30 days, and it is not possible to know the average disorder during a specific period, and the disorder caused by the change in the environment. It was difficult to know quickly whether or not.

The present invention has been made in view of the above problems, and in order to quickly and accurately know the adhesion state of scale in the circulation system of papermaking process water, and to suppress the generation of scale in the circulation system. An object of the present invention is to provide a scale adhering device for quickly and accurately setting the type and concentration of water treatment chemicals added to the system.

[0006]

According to the present invention, the papermaking process water, which is disposed in a part of the circulation system of the papermaking process water and into which the papermaking process water flows, and the papermaking process water that has flowed in from the inflow port are flowed. A container member having a discharge port that is discharged above the inlet, a stirring blade that is driven to rotate near the inflow port and that stirs the papermaking process water that has flowed into the container member from the inflow port, and is disposed near the discharge port. There is provided a scale adhering device comprising a net capable of depositing scale components in the papermaking process water on the surface thereof by contacting the papermaking process water.

That is, the inventors of the present invention grasped the adhesion state of scale in the circulation system of papermaking process water, and when setting the kind and addition concentration of the scale inhibitor for suppressing the generation of scale, We have found various conditions for developing the adhesion state in real time, preferably at an accelerated rate, with a high correlation with the inside of the system, and have completed a scale adhesion device provided with these conditions.

Since the container member has an inflow port for inflowing the papermaking process water therein and an outlet for discharging the papermaking process water flowing in from the inflow port above the inflow port, the papermaking process water rising in the container member. A stream can be created, which allows good contact between the scale components in the papermaking process water and the mesh. However, if the discharge port is set below the inflow port, it will be difficult to achieve good contact between the papermaking process water containing pulp fibers and bubbles that are likely to float and aggregate, and the net. Further, if such papermaking process water is forced to flow downward, a large driving force is required and the apparatus configuration becomes complicated. By forming the container member with a transparent container, for example, it is possible to observe the adhesion state of the scale to the net from the outside.

If the inlet is opened at the bottom surface of the container member or a side surface near the bottom and the outlet is opened at the side surface above the inlet, a flow rising in a substantially vertical direction can be formed. Therefore, it is possible to achieve good contact between the scale component in the water in the papermaking process and the net.

It is preferable that the net is arranged near the discharge port and has a structure capable of coming into contact with the papermaking process water to deposit scale components in the papermaking process water on the surface (the surface of the wire) to adhere.
By using such a net, the adhered state of the scale in the system can be expressed in real time with high correlation with the system, preferably in an accelerated manner. Since the net is detachably supported in the container member through the support member for supporting the net, the net can be taken out from the inside of the container member to the outside and can be attached to the inside of the container member from the outside. The scale attached to the surface of the net can be easily observed or measured.

The net is preferably arranged so that the papermaking process water flows along its surface. In other words, no matter how the direction of the net is changed in the flow of papermaking process water, there is a slight flow of papermaking process water passing through the mesh, but most of the flow of papermaking process water By setting the orientation of the mesh in the flow of water in the papermaking process so that it does not pass through the mesh, the mesh of the mesh is blocked by the pulp fiber and scale is attached to the surface of the mesh. Is prevented.

[0012] The net is preferably made of the same material as the material constituting the circulation system of the papermaking process water.
Examples of the commonly used stainless steel include, but are not particularly limited to. The diameter of the wire that forms the net is 0.05 to 0.29 mm
A degree is preferable. The mesh preferably has a mesh size of 40 to 200 mesh. If it is coarser than 40 mesh, the contact area becomes small, and the scale attached to the surface of the net is likely to come into contact with pulp fibers in the water in the papermaking process and peel off easily. If it is finer than 200 mesh, the flow of water in the papermaking process passing through the mesh becomes poor, and it becomes difficult for scale to adhere to the surface of the mesh.

The types of stirring blades include a paddle type, a flat blade turbine type, and a propeller type having a pitch. If a propeller type stirring blade is used, it is possible to control the flow velocity in the rotation axis direction. The stirring blades arranged as described above can set a large flow path length until the stirred papermaking process water comes into contact with the net and is discharged from the discharge port. Good contact between the components and the net can be achieved.

The propeller type stirring blade has a diameter of 5
One having 0 to 100 mm, 2 to 4 blades, and connected to a rotary drive source via a relatively long rotary shaft can be mentioned. The rotation speed of such a stirring blade is about 50 to 200.
It is preferably driven to rotate at rpm. When the rotation speed is lower than 50 rpm, it becomes difficult to uniformly agitate the papermaking process water containing pulp fibers and bubbles. When the rotation speed is higher than 200 rpm, the scale attached to the surface of the net is likely to peel off.

The container member is preferably arranged in a bypass flow path or a branch flow path of the circulation system. By disposing the container member in the bypass passage of the circulation system, the papermaking process water discharged from the discharge port of the container member can be returned to the circulation system, and therefore the papermaking process water discharged from the discharge port is separately treated. The mechanism for is unnecessary. Further, if the container member is disposed in the branch flow path of the circulation system, a mechanism for separately treating the papermaking process water discharged from the discharge port of the container member is required, but the scale in the system is not generated. Drugs to suppress
Even if added to the papermaking process water in the branch flow path on the upstream side of the mesh, the test can be conducted by changing the kind and addition concentration of the drug without returning the drug to the system.

A plurality of container members can be arranged in parallel or in series in the bypass channel or the branch channel.
By arranging multiple container members, it is possible to perform tests by changing the type and concentration of addition of the drug, and to arrange a net of various materials that make up each part of the circulation system on each container member. It can be installed and tested. At least 1
By providing each of the container members with the chemical addition section for adding the chemical to the papermaking process water flowing in from the inflow port, the effect of the chemical addition in the system can be confirmed by the net.

The liquid level of the papermaking process water flowing from the inflow port into the container member is maintained so that the liquid level of the papermaking process water is maintained at a constant water level above the discharge port. Since the adjusting unit for adjusting is further provided, the contact condition of the papermaking process water with respect to the net, that is, the flow velocity of the papermaking process water and the contact time with the net can be kept constant, whereby the scale in the circulation system can be maintained. The adhered state of can be accurately grasped.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on embodiments. The present invention is not limited to this.

The scale adhering device of the present invention will be described with reference to FIG. In FIG. 1, the scale adhering device 1
Reference numeral 0 denotes two container members 1 arranged in the bypass flow path of the circulation system 100 for the papermaking process water, and rotary blades 2 (stirring blades) for stirring the papermaking process water flowing into each container member 1. It is detachably arranged in the container member 1 and mainly comprises a net 3 which comes into contact with the papermaking process water stirred by the rotary blades 2. The circulation system 100 of the papermaking process water to which the scale adhering device 10 of the present invention is applied includes a papermaking process section 7, a cebuol 8 containing the white water collected from the papermaking process section 7, and a white water contained in the cebuol 8. It is composed of a pump 9 for sending to the paper making process section 7.

The container member 1 is a container made of polyethylene resin having a capacity of 50 L and having a rectangular cross section. The container member 1 is provided with a lid 13 and has an inflow port 11 into which the papermaking process water flows and a papermaking process water flowing from the inflow port 11. Has a discharge port 12 for discharging the above from the inflow port 11. The inflow port 11 opens at the bottom surface of the container member 1, and the discharge port 12 opens at the side surface of the container member 1. The two container members 1 are connected to each other in parallel to the circulation system 100 via a flexible pipe 5 made of a resin, and one of the container members 1 has a chemical agent in the papermaking process water that has flown into the inside from the inflow port 11. It is provided with a medicine adding section 4 for adding.

The chemical addition section 4 has a chemical addition port section 41 which is opened on a side surface facing the discharge port 12 of the container member 1,
A drug addition pump 42 connected to the drug addition port 41 via a flexible tube 5 made of resin, a drug tank 43 containing a drug to be sent to the drug addition port 41 by the drug addition pump 42, and addition of a drug. And a valve 44 for adjusting the amount.

One end of a flexible pipe 5 made of resin is connected to the air vent of the pump 9, and the other end of the flexible pipe 5 serves as a branch pipe and is connected to each inflow port 11. In each branch pipe of the flexible pipe 5, the liquid level of the papermaking process water that has flowed into the container member 1 through the inlet 11 is maintained at a constant water level above the outlet 12, so that A valve 14 is provided as an adjusting unit that adjusts the liquid level of the papermaking process water that flows into the inside 1. The outlets 12 are respectively connected to the flexible pipes 5 made of resin, and these flexible pipes 5 are assembled to return the papermaking process water to the sebuol 8.

The stirring blade 2 is composed of two propeller blades arranged almost directly above the inflow port 11 and has a diameter of 50 mm.
Of the rotary blade 21, a lower end of the rotary blade 21 fixedly supporting the rotary blade 21, and an upper end of which is connected to a motor 23, and a motor 23 for rotating the rotary shaft 22. Rotor 21
Is disposed almost directly above the inflow port 11, so that the flow path length until the stirred papermaking process water comes into contact with the net 3 and is discharged from the discharge port 12 can be set to be large. Therefore, good contact between the scale component in the papermaking process water and the net 3 can be achieved. Rotor blade 2 connected to rotary shaft 22
1 is rotated by a motor 23 in the range of at least 50 to 200 rpm.

The mesh 3 is made of stainless steel (SUS) having a diameter of 0.07 mm.
304) consisting of a plurality of net bodies 31 woven of wire rods and a support member 32 for detachably supporting these net bodies 31. The mesh main body 31 is formed in a flat plate shape having outer dimensions of 70 mm × 40 mm, and the mesh size is 140 mesh. The support member 32, with the net body 31 attached,
Each net body is detachably supported on the lower surface of the lid portion 13 of the container member 1 and has the attached net body 31 in the vicinity of the outlet 11 so that the papermaking process water flows along the surface of the net body 31. 31 is arranged in parallel with the flow of water in the papermaking process. As a result, most of the flow of water in the papermaking process does not pass through the mesh, so the mesh of the mesh body 31 is blocked by the pulp fibers, and the scale is prevented from adhering to the surface of the mesh body 31. Can be prevented. However, in this test example, the flow of water in the papermaking process passing through the mesh of the net body 31 is also regarded as one factor contributing to the adhesion of scale.

Test Example An example of a scale adhesion state confirmation test conducted by connecting the scale adhesion device 10 of the present invention to the circulation system 100 of papermaking process water will be described below. In FIG. 1, the papermaking process unit 7 of the papermaking process water circulation system 100 is composed of a papermaking whitewater circulation system of a pulp mill forming a newspaper production process, and in this papermaking whitewater circulation system, it is fed from a whitewater silo (not shown). The white water is diluted to a pulp concentration of about 0.8% by weight and refluxed to the cebuol 8 (the flow of the white water is shown by an arrow in the figure).

The white water is supplied from the pump 9 and sent to the scale adhering device 10 by the head pressure.
The white water flowing into the two container members 1 has a liquid level of the white water flowing into the container member 1 from the inflow port 11,
The valve 14 was adjusted so that a constant water level was maintained at the upper part of each container and the same amount was supplied into each container member 1. In the medicine tank 43, one of the medicines A to I described later was sequentially replaced and stored. Net body 31 (outside dimensions
70 mm × 40 mm, mesh size 140 mesh, SUS304) was attached to the support member 32, and the support member 32 was supported in each container member 1. Further, the rotation speed of the rotary blade 21 rotated by the motor 23 was set to be sequentially switched to three stages of 10, 100 and 1000 rpm.

First, the scale adhering device 10 was prepared by using white water (pH 5.0, liquid temperature 40 ° C.) containing calcium sulfate contained in Cebuol 8 as a circulating water amount of 15 L / min and a residence time of about 3 minutes in the container member 1. Circulated. Then, the amount of the chemical added from the chemical tank 43 is changed to the scale attaching device 10
The valve 44 was adjusted so that the total amount of the pulp slurry sent out to 10 mg / L was adjusted, and the chemical addition pump 42 was driven. After 24 hours have passed since white water was sent to the scale adhering device 10, the support member 32 was taken out from each container member 1 and the net body 31 attached to the support member 32 was replaced with a microscope (Digital HF Microscope VH manufactured by Keyence Corporation). -8000).

Further, the net body 31 attached to the support member 32 is formed of a flat plate (50 × 30) of stainless steel (SUS304).
The above test was carried out in place of the test piece composed of (.times.0.07 mm) and the test piece composed of a polyethylene resin plate (50.times.30.times.1.0 mm). Further, the above test was conducted by sequentially switching the rotation speed of the rotary blade 21 to three stages of 10, 100 and 1000 rpm.

[0029] Drug A used in the above adhesion state confirmation test
~ I is shown in Table 1 below together with the component constitution.

[0030]

[Table 1]

In the adhesion state confirmation test performed by sequentially replacing the chemicals A to I in Table 1 with the chemicals tank 43 and adding the respective chemicals, the state of the surface of the net body 31 observed by a microscope is shown. 2 and FIG. Figures 2 and 3 show the sample without the drug added during the test (Figure 2).
And, each image photograph of the specimen to which each drug was added at the time of the test is shown.

As a result of observation with a microscope, the net main body 31 attached to the support member 32 was replaced with a test piece made of a flat plate of stainless steel (SUS304) and a test piece made of a flat plate of polyethylene resin, and the above test was conducted. In this case, scale adhesion was not confirmed regardless of the number of rotations of the rotor blade 21 and the presence or absence of addition of a chemical. The net body 31 is attached to the support member 32, and the number of rotations of the rotary blade 21 is set to 10 in the container member 1 in which no chemical is added.
Adhesion of calcium sulfate scale was confirmed only during tests performed at rpm and 100 rpm.

In the test conducted with the number of rotations of the rotary blade 21 being 10 rpm, it was confirmed that a large amount of pulp fibers in white water were attached together with the attachment of calcium sulfate. In addition, when the number of revolutions of the rotary blade 21 was 1000 rpm and stirring was performed, adhesion of scale was not confirmed. When a fast water flow is generated on the surface of the net body 31, the net body 31
It is considered that the scale easily peels off before the scale adheres to the surface of the. When the chemical was added, calcium sulfate was not adhered regardless of the number of rotations of the rotary blade 21.

About the test performed by adding each of the chemicals A and B in the above adhesion state confirmation test performed by sequentially replacing the chemicals A to I in Table 1 with the chemicals tank 43 and adding each chemical The white water in the container member 1 was sampled, and the sulfate ion concentration, total calcium concentration and calcium ion concentration in this white water were measured. The results are shown in Table 2 below.

[0035]

[Table 2]

The data shown in Table 2 as "non-added" is the container member 1 immediately before the addition of the drugs A and B, respectively.
It was measured by collecting white water in the container, and the data "added" in Table 2 was measured by collecting white water in the container member 1 24 hours after the addition of the drugs A and B, respectively. It was done. From Table 2, it can be seen that the scale components in the white water were reduced by adding the agents A and B to the white water, respectively.

As shown in the above-mentioned test example, in the scale adhering condition confirmation test conducted by connecting the scale adhering device 10 to the circulation system 100 of the papermaking process water, the stirring condition by the rotor blade 21 and the rising flow were examined. Depending on the structure of the container member 1 to be formed, conditions such as stirring and flow rate of white water are adjusted, and the white water subjected to such treatment is contacted with the stainless net 3 which is a contact member.
To allow the scale to adhere to the surface. As a result, it is possible to directly check the scale attachment state directly on site without the scale attachment being hindered by pulp fibers or the like in the white water.

[0038]

According to the present invention, when the scale adhesion state in the circulation system of the papermaking process water is grasped and the kind and addition concentration of the scale inhibitor for suppressing the generation of scale are set, the scale adhesion state in the system is It is possible to provide a scale adhering device having various conditions for exhibiting in a real time, preferably at an accelerated rate, with a high correlation with the inside of the system.

The papermaking process water is a slurry containing pulp fibers and air bubbles, and the pulp fibers are easily floated to the upper layer and aggregated, and the scale component is easily collected in the pulp fibers. By adjusting the condition of the flow of white water in the container and the container member, and by using a net as a member that contacts the white water and adheres the scale, it is possible to confirm the scale adhesion state without being affected by the pulp fibers in the white water. it can. According to the present invention, the adhesion state of scale in the circulation system of the papermaking process can be quickly and accurately determined, and the kind and the concentration of the water treatment chemical added to the system in order to suppress the generation of scale in the circulation system can be determined. A scale application device is provided for quick and accurate setting.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a scale adhering device arranged in a papermaking white water circulation system of a paper pulp mill according to an embodiment of the present invention.

FIG. 2 is an image photograph showing the state of the surface of the net body observed with a microscope in the adhesion state confirmation test performed using the scale adhesion device of FIG.

FIG. 3 is an image photograph showing the state of the surface of the net body observed by a microscope in the adhesion state confirmation test performed using the scale adhesion device of FIG.

[Explanation of symbols]

1 container member 2 stirring blades 3 net 4 Drug addition department 7 Papermaking process department 10 Scale attachment device 11 Inlet 12 outlet 14 valve (flow rate adjustment part) 21 Rotating blade (stirring blade) 31 Net body 32 Support member 100 Papermaking process water circulation system

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C02F 5/14 C02F 5/14 B (72) Inventor Kenji Nishie 2-10, Higashi-Awaji, Higashiyodogawa-ku, Osaka-shi, Osaka No. 15 Katayama Chemical Research Institute Co., Ltd. F-term (reference) 4L055 DA05 DA09 DA17 EA15 EA19 FA20

Claims (10)

[Claims] 1. A part of a circulation system of paper manufacturing process water,
A container member having an inflow port for inflowing the papermaking process water into the inside and an outlet port for discharging the papermaking process water flowing in from the inflow port above the inflow port, and being driven to rotate in the vicinity of the inflow port, inside the container member from the inflow port. A scale that includes a stirring blade that stirs the papermaking process water that has flowed into the papermaking machine, and a net that is disposed near the discharge port and that can contact the papermaking process water and cause the scale components in the papermaking process water to deposit and adhere to the surface. Adhesion device. 2. The scale adhering device according to claim 1, wherein the inflow port is opened at a side surface which is at or near the bottom surface of the container member, and the discharge port is opened at a side surface above the inflow port. 3. The scale adhering device according to claim 1, wherein the net is detachably supported in the container member via a support member that supports the net. 4. The scale adhering device according to claim 1, wherein the mesh has a mesh size of 40 to 200 mesh. 5. The scale adhering device according to claim 1, wherein the mesh is arranged so that water for the papermaking process flows along the surface of the mesh. 6. The stirring blade has a rotation speed of 50 to 200 rpm.
The scale adhering device according to claim 1, which is rotationally driven by the. 7. The scale adhering device according to claim 1, wherein the container member is provided in a bypass passage or a branch passage of the circulation system. 8. The scale adhering device according to claim 7, wherein a plurality of container members are arranged in parallel or in series in the bypass channel or the branch channel. 9. The scale adhering device according to claim 8, wherein at least one container member is provided with a chemical addition unit for adding a chemical to the papermaking process water that has flowed in from the inflow port. 10. A flow rate of papermaking process water flowing from the inflow port into the container member so that the liquid level of the papermaking process water flown into the container member from the inflow port is maintained at a constant water level above the discharge port. The scale adhering device according to claim 1, further comprising a flow rate adjusting unit that adjusts.