JPH02264098A - Method for adding starch liquid in paper making process from external source and apparatus therefor - Google Patents

Abstract

PURPOSE:To prevent the nozzle-clogging of a spray unit and to facilitate the control of application rate of starch by ejecting starch liquid from a spray unit with air and feeding starch liquid, etc., from a mixing unit provided with a reducing valve, flow meter, etc. CONSTITUTION:A starch liquid is passed through a flow-controller 2 having a reducing valve 1, transferred together with chemicals supplied from a chemicals flow controller 3 into a mixing chamber 5 and introduced into a spray unit via a flow rate measuring part 6. Air supplied from an air controller 11 is also introduced into the spray unit. The starch circulating through a starch- circulation pipe is mixed with the air circulating through an air-circulation pipe and the mixture is sprayed in circular or semicircular shape. The spraying rate can he controlled with the reducing valve while measuring the rate with flow meters 7,8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method and apparatus for externally adding starch liquid in paper manufacturing.

(Prior Art) Recently, in the paper manufacturing industry, the reuse of waste paper has been increasing due to resource shortages and cost reductions.

In addition, as the number of recycled used papers increases, the fibers are becoming shorter, resulting in a significant decrease in the strength of the paper being made.

In order to compensate for this, polymeric chemicals such as polyacrylamide or other paper strength enhancers have been added internally to the raw material, but since the raw material is expensive, solid starch has been replaced in recent years in order to reduce costs. The law of external attachment was adopted.

In other words, starch is mixed with water in a tank, stirred, and pumped into a nozzle pipe, where it is sprayed in a circle or fan shape by pressure from a small nozzle diameter of 0.5 to 1 m, and the remaining starch liquid is returned to the tank. However, because the process was not appropriate, its widespread use was slow, and many problems occurred even in paper machines that had already adopted it.

These conventional techniques have the following secondary drawbacks.

■Because the nozzle has a small diameter, the nozzle opening may become clogged, resulting in areas where no additive is added.

■If it gets clogged, the spray shape will become unstable and non-additive will become uneven.

■If the concentration is high, the nozzle opening will be clogged, and if the concentration is low (2 to 5%)
) can only be done.

If the 0 diameter is increased, the amount of spraying will increase, resulting in soil deformation and excessive moisture.

■When the amount of spraying increases, starch lumps are generated and fall onto the paper web, contaminating the surrounding area.

■Due to the circulation cycle, it is impossible to measure the amount of spraying.

■ Slime (viscous material) is generated due to the cycle and causes clogging.

(Problems to be Solved by the Invention) In order to eliminate the drawbacks of the prior art and prevent the spray unit from clogging with starch liquid, a 1.5 to 2 mm nozzle is used for spraying, and air is used instead of pressure. ,Installation location,
The mixing unit has been made smaller and lighter in consideration of maintenance, and the mixing unit can control the amount with a pressure reducing valve, check the spray amount with a flow meter, and add auxiliary chemicals to starch.
This is a method for externally adding starch or chemicals in paper manufacturing, which consists of two units, and an apparatus for externally adding starch or chemicals therein.

(Means for Solving the Problems) The present invention provides for feeding a starch solution mixed with a required amount of water between paper sheets during paper production via a starch flow rate control section 2 that adjusts the flow rate with a pressure reducing valve 1. If necessary, the chemical controlled by the pressure reducing valve 4 is mixed with the starch liquid via the chemical flow rate control unit 3, and the mixture is ejected into the mixing chamber 5.
When discharging via the flow rate measuring unit 6, the amount of chemicals mixed in is adjusted while detecting the counts of the first flow meter 7 and the second flow meter 8, and the mixture is sent to the liquid vibrator 10 of the spraying unit 9. Air from part 11 to air vibe 1
2, the starch liquid is sent from the liquid vibrator 10 to the nozzle body 13, and while being circulated by the reflux pipe 14, the starch liquid is ejected from the air vibrator 12 to the cap 16 via the nozzle 15.
It circulates.

Air is ejected from the tip of the nozzle 15, and the air and starch liquid are mixed and ejected in a circular or fan shape.
a starch flow control section 2 which is configured with a flow meter 7 and sends out the starch liquid mixed with water via the first flow meter 7; a chemical flow control section 3 which is configured with a valve 19 and a pressure reducing valve 4 and which jets out chemicals; A mixing chamber 5 that mixes the starch liquid and chemicals at the mixing inlet, and a second flow meter 8 that measures the discharge flow rate.
A discharge device 21 configured with a flow rate measuring section 6 disposed with a
a mixing unit 24 that is configured with an air control section 11 that includes a pressure reducing valve 22 and a valve 23;
Spreading unit 9 includes a nozzle body 13 surrounding a nozzle 15 with a cap 16, a starch liquid return port 25 in the main part of the nozzle body 13, and an air inlet 26 in the vicinity of the nozzle outlet of the nozzle body 13. From the dispersion unit 9, which has an air chamber 27 in the upper part and a starch liquid chamber 28 in the lower part, and an air reflux chamber 29 connected to the air chamber 27 and a starch liquid reflux chamber 20 directly connected to the starch liquid chamber 28 on the outside. The gist of this is that

(Function) To explain the present invention in detail with reference to the drawings, when the valve 18 of the flow rate control unit 2 is opened, the starch liquid flows into the flow rate control unit 2, the flow rate is regulated by the pressure reducing valve 1, and the starch liquid is regulated by the first flow meter 7. The flow rate is now confirmed.

At the chemical mixing port 30 provided at the entrance of the mixing chamber 5, the starch liquid and the chemical sent out from the first flow meter 7 are mixed. is tapered to about one-third to one-fifth of the discharge port.

When the starch liquid and the chemical are discharged into the mixing chamber 5, they are stirred and dispersed by the self-blade rotation flow to form a mixed liquid containing the chemical.

The flow rate of the mixed liquid is measured by the second flow meter 8 of the flow rate measurement unit 6, so by detecting the flow rate difference with the first flow meter 7, the amount of the mixed liquid is confirmed, and the mixed liquid is sent to the spraying unit 9. become.

In other words, it has become possible to freely adjust the flow of chemicals.

When the valve 19 of the chemical flow control section 3 is opened, the chemical flows into the chemical flow control section 3, the flow rate is adjusted by the pressure reducing valve 4, and the chemical is sent into the mixing chamber 5 together with the starch liquid via the chemical mixing port 30. It has become.

In the case of high viscosity, the flow rate measurement of the chemical can be confirmed by looking at the difference in flow rate between the second flow meter 8 and the first flow meter 7 because the equipment is large and expensive.

When the valve 23 of the air control section 11 attached to the mixing unit 24 is opened, air flows into the air control section 11, and the air inflow is adjusted by adjusting the pressure reducing valve 22, thereby controlling the shape and amount of spraying. It is supposed to be.

The starch liquid sent out from the mixing unit 24 is.

The starch liquid is sent to the liquid pipe 10 from the starch liquid inlet 31 of the sprinkling unit 9, and is discharged from the center opening of the nozzle 15 from the nozzle body 13 attached to the vibrator of the sprinkling unit 9.

On the other hand, air is sent out from the air control section 11 attached to the mixing unit 24 and sent out to the air vibrator 12 from the air inlet 32 of the dispersion unit 9.
The water flows into the nozzle body 13 attached to the vibrator, passes through the outer periphery of the nozzle 15, is atomized with water in the cap 16, and is sprayed in a circular or fan shape depending on the shape of the outlet. ing.

When there is a surplus in the starch liquid sent to the nozzle 15 by the liquid vibrator 10, it is returned to the starch liquid reflux chamber 20, and the liquid pipe is passed through the starch liquid reflux port 25 provided intermittently depending on the length. This equalizes the liquid pressure at each nozzle, so even if the number of nozzles increases and the spray unit becomes longer, the discharge amount will remain the same even if injected from one side. It becomes uniform.

Air is also sent out while adjusting the air pressure, but if excess air is generated, it is returned to the air recirculation chamber 29, and the air chamber 27 of the air vibrator 12 is passed through the air recirculation port 26 provided according to the length. It is now back to .

Since both ends of the spraying unit are equipped with removable sealing plates 33, if starch settles, it can be easily washed away, and the nozzle can be prevented from clogging due to the generation of putrid sludge due to starch. It looks like this.

(Effects of the present invention) The present invention prevents the nozzle of the sprinkling unit from becoming clogged with starch liquid when adding starch liquid externally in paper manufacturing, reduces the size and weight of the unit by using air, and allows the spraying amount to be measured using a flow meter. In addition, the surplus of starch liquid and air is refluxed to ensure efficient spraying.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a mixing unit used in the present invention. Figure 2 is a schematic diagram of the dispersion unit. Figure 3 is a slope view of the dispersion unit. Figure Middle 1, Pressure reducing valve 2 Starch flow rate control section 3, Chemical flow rate control section 4, Pressure reducing valve 5, Mixing chamber 6, Flow rate measuring section 7, First flow meter 8: Second flow meter 9, Spraying unit IO: For liquid Pipe ll: Air control section 12: Air pipe 33: Sealing plate

Claims (2)

[Claims] (1) During paper manufacturing, the starch solution mixed with the necessary amount of water is sent between the paper sheets via a starch flow control section that adjusts the flow rate with a pressure reducing valve, and if necessary, the starch solution is sent out via a chemical flow control section. When the chemicals regulated by the pressure reducing valve are mixed with the starch liquid and ejected into the mixing chamber and discharged through the flow meter, the amount of chemicals mixed in is measured while detecting the counts of the first flow meter and the second flow meter. The starch liquid is adjusted and sent to the liquid pipe of the spraying unit, while air is sent from the air control unit to the air pipe, and the starch liquid is sent from the liquid pipe to the nozzle body, and the starch liquid is circulated through the reflux pipe through the nozzle. A method for externally adding a starch liquid in paper manufacturing, in which air is circulated from an air pipe to a nozzle tip while being circulated through a reflux pipe, and the air and starch liquid are mixed and ejected in a circular or fan shape. (2) A starch flow control unit that is composed of a valve, a pressure reducing valve, and a first flow meter, and sends out the starch liquid mixed with water via the first flow meter; a chemical that is composed of a valve, and a pressure reducing valve, that sprays out chemicals A discharge device consisting of a flow rate control section, a mixing chamber where starch liquid and chemicals are mixed together, a flow rate measurement section equipped with a second flow meter that measures the discharge flow rate, and an air pressure reducing valve and valves. A mixing unit that includes a control unit, a nozzle body surrounding a nozzle with a cap, a starch liquid reflux port in the main part of the nozzle body, and an air reflux port near the nozzle spout of the nozzle body. Paper making machine consisting of a dispersion unit that has an air chamber at the top and a starch chamber at the bottom, and an air reflux chamber connected to the air chamber and a starch liquid reflux chamber directly connected to the starch liquid chamber on the outside of the dispersion unit. External addition equipment for starch liquid in manufacturing.