JPS58501825A - Method for manufacturing fiberboard by wet method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Method for manufacturing fiberboard by wet method The present invention is a method for manufacturing fiberboard using a lignocellulose-containing material. The chips are preheated under high pressure in a hot saturated steam atmosphere and then decomposed at atmospheric or high pressure. The fiberized and defibrated material is suspended in two-way water to form a wet sheet. The wet sheet is precisely dehydrated under heat, and then squeezed. Closed water wet method in which drained water is returned to the suspension process The present invention relates to a method for manufacturing fiberboard according to the present invention.

When manufacturing fiberboard by the method described above, softwood or hardwood, wheat Regeneration by any kind of annual or perennial plants such as Dismissal after crushing the gnocellulose-containing material into suitable small pieces such as chips. is normal. These small pieces (hereinafter referred to as chips for the sake of simplicity)'r It is mechanically decomposed and decomposed in a steam atmosphere under high temperature and pressure.

The temperature at the time of removal V′i depends on the type of starting material, the quality of the raw material, and the supplied crushing energy. Therefore, the temperature can be maintained within the range of 125 to 200°C. Defibration is usually single or Various types of disc grinders are used, such as crushers with dual rotating grinding elements. It is done.

In most cases, the temperature during defibration is within the range of 150-170°C, depending on the steam pressure. Correspondingly retained. Depending on the fiber material supplied, the crushing energy is between 100 and 3 Varies within the range of 00 kwh/t o n, however, wood chips are Showa 58-501825 (2) When final defibration and pulverization are performed in one step, the dry material is usually kwh/l On.

When defibrating at 170°C using coniferous wood as a starting material, the Approximately 8% of the quality is hydrolyzed by polysaccharides of various compositions in the water contained in the chips. Some are dissolved by the solution, some are released into the backwater, and some are released into the product stream. Included in the fiberboard. As a result, the complete rose dock water In the formula, when the Phino board unit + ri is subjected to high temperature press action, Turns black or otherwise produces black spots and also shows a tendency to stick to the press plate .

As mentioned above, (in order to solve the problem, it is necessary to close the closed water system, but Therefore, it is necessary to reduce the amount of organic substances released into the fiber dart. Ru. ) In order to reduce the content of soluble substances in water, conventional Vi packs were used. It was common practice to drain a quarter of the water and replace it with fresh water. extraction It is necessary to make the water unethical, and this is why the natural burning of the black water and the Combinations of K, evaporation, and l/'i, various biological treatments have all been carried out. Ru. All previously known treatment methods have the disadvantage of being expensive and resulting in expensive products. It was.

The object of the present invention is to reduce the This project aims to provide a new method to reduce the release gate of organic substances to In order to achieve this goal, the nozzle obtained in the defibration process is dehydrated and Impregnating the chip before the iron cracking process with an aqueous solution containing organic substances released during the process. It is characterized in that it is returned to the processing step by.

According to the present invention, the supplied chips are impregnated with a water bath solution containing atomistic substances released during the defibration process. When defibrating at 170°C, the dissolved substances are virtually completely confined in the pulp. It binds and cannot be removed by washing with water. Inaccuracy of dissolved substances The conversion to this state is not due to the interaction of some chemical treatments! 2I-like nature Therefore, it is probably being done. Substances released during the defibration process are substantially different from polysaccharides. It undergoes polymerization and condensation to dissolve in water and convert it into a sharp substance.

1. Polysaccharides are tightly absorbed inside and on the fiber walls and cannot be eluted into water. do not have. As is known, when chips are impregnated with water, they have a dry content of 50 chips. Let 1 ton of completely dry chips of coniferous wood absorb 1-■ water. Since it is possible to According to the present invention, it is possible to return a considerable portion of the removed material to the chip. It can be made harmless at some point. According to the present invention, the chip is first heated to 100°C. It is treated with steam to soften it, and then it is compressed to remove excess water M41), resulting in a positive return. The chip is swelled in the O impregnation bath solution to absorb the layer solution. Impregnate by soaking. Pressure is applied at the same time to facilitate the absorption of 6 liquids. You can also

How much of the emitted organic material must be silenced depends on the amount of emitted material. How much of that is 7 eyes? - Is it possible to leave it on the card? Determined by once of the substance dissolved in the. /The degree is 5 in # in the Gutsuku quota. ．． If a height such as By using 0% dry ingredients for impregnation by directly dehydrating and squeezing water bath water, In this case, the condition is that the entire amount of water bath liquid is absorbed by the chip. Limited to the gates you can get.

・If the if in the water must be lowered to 3.0% or less, 1 Usually, it is necessary to add additional water, and dehydration is performed once or several times while adding water in the middle. Perform the process. In order to reduce the content of dissolved substances to the above-mentioned level, The amount of aqueous solution squeezed out is so large that it exceeds the amount that the chip can absorb during the impregnation process. It is necessary to add water to the dehydration process A of the It is necessary to reduce the amount by 1 to an amount suitable for evaporation and impregnation.

Sewage originating from other parts of the closed water system, e.g. It may be desirable to render the wood water expressed after the steaming process harmless. In such cases, this wastewater is used to carry out a mechanical dewatering process to remove the released substances. It is preferred to dilute the final fibrillated fiber before defibration. In such case, tip The aqueous solution is so large that it needs to be evaporated to make it absorbable. Usually obtained.

Evaporation of the strained aqueous liquid can be carried out by the conventional evaporation method, but It is preferable to do this under reduced pressure to prevent problems caused by grime, or can also evaporate water with air by evaporating a heated aqueous solution with air. It can be discharged as a mixed gas with air.

The drawing is a schematic diagram showing a flow sheet of a preferred plant implementing the method of the present invention. It is a schematic diagram.

The method will now be described with reference to preferred embodiments shown in the drawings.

In the illustrated example, the chips are conveyed to the steaming vessel 12 by the conveyor 10, and the planar Steaming water is drawn out from the cyclone 16 belonging to the latter half of the steaming vessel through the pipe 14 to the steaming vessel. The chips are heated in the steaming vessel by air. Wet chips are screw press 1 8, and the water is mechanically suspended in this screw press. .

The water is drained through a pipe 20 into a container 22 placed vertically below.

The compressed chips compressed by the screw press 18 are pushed into the impregnating container 24, and this In the container, it expands and absorbs the aqueous liquid carrying the released substances, such as polysaccharides. this water bath The liquid is obtained by mechanical dehydration of ξ2 m nozzles in a later step in the plant. It is fed into the impregnating container 24 by a tube 26. Is the chip impregnated container 24? The air is fed into the preheater 30 by the feed screw 28.

This preheater receives steam pressure from the steam delivered by pipe 32; The branch pipe 32ad opens into the steaming vessel 12. Chips heated by steam is sent to the defibrator 36 by the screw feeder 34, and the motor 3 It is decomposed by the defibrator operated by 8 and produces nokulp. . The organic substances in the finishing nozzle supplied during the impregnation process in vessel 24 are insoluble. This finish/ξ loop has been changed to the state of blown into the tube 16. The ξ loop is cyclo from the tube 16 to a container 48 equipped with a stirring device. The container 22 is filled by the tube 42. The wood water drained from the screw press 1B is transferred to the container 2. 2 through a pipe 42 to a container 48 by a pump 44. No ξ loop is container 4 8 through a chute 50 to a high pressure screw press 52. - Mechanically dehydrated in a press. This allows defibration with a defibrator. A water bath liquid containing the organic substances released during the process is obtained, and this aqueous solution is passed through the screw press. from the tank 52 through a pipe 54 into a container 56 from which a pump 58 The W2O is sent to the cooling tower 64 via the heat exchanger 62, and a portion of the water is evaporated.

The heating in the preheater 62 is caused by the steam drawn from the cyclone 16 through the pipe 14a. This steam is then led out of the preheater 62 via a pipe 66. Like this A part of the water is evaporated as a mixed gas of steam and air in the cooling tower 64, and this is Therefore, air is supplied by the fan 68. After some water has evaporated, the container is The pump 70 sends fresh water through the pipe 26 to the impregnating container 24 as described above. Used to impregnate loaded chips.

The pulp flows down from the high-pressure screw press 52 into the pulp container 72, and this Inside the loop container, water is simultaneously pumped from tank 74 to pump 76 and Input by W78. The pulp suspension solution finally obtained is pumped by the pump 80. is passed through a pipe 82 to a forming machine 82, and this forming machine 82 The water flowing out from the tank 74 is collected through a pipe 86. damp The sheet is sent to a hot press 88 where it is mechanically dehydrated. and finally dried by heating and pressure in the usual manner to obtain the final product. .

Next, various conditions in the above-mentioned processing steps will be explained below. However, after The description below only represents one embodiment of the invention, and the invention is not limited to the numbers shown below. It's not something you can do.

Example Raw material chips of Pineaceae wood at a rate of 5ooohQ per hour, along with 8000kf of water. 19251w of steam is supplied into the steaming vessel 12 through the pipe 14. Send the chips containing 100% moisture to the screw press 18 and reduce the moisture to 55%. 2 is dehydrated to a temperature of the water containing the polysaccharide release substance is pushed into the impregnating container 24 and expanded in the impregnating container. After the solution is absorbed, it is sent to the preheater 30 by the feed screw 28, and this preheating Steam was supplied to the vessel 30 through a pipe 32, and the temperature was maintained at 170°C by applying steam pressure. 1 A chip heated to 70°C containing absorbed moisture and organic substances Then, it was sent to the defibrator 36 by the screw feeder 34.

In the impregnation process, the impregnated organic substances are changed to a non-uniform state and are sprayed with a finish/ξ loop. It was blown into the cyclone 16 through the outlet pipe 40.

Sending the norupu from the cyclone into a container 48 by a screw conveyor 46, In this container 48, 3380 k g of wood water was introduced at the same time. Thoroughly agitate the flow in vessel 48. from the container 48 to the high-pressure screw press 52, and the screw press Therefore, the total amount of water released from the dewatering press is 10,400 ml and the chips are 640 ml of water. The 4004 soluble substances from the ky substances flowed down into each vessel 56. 245 o'clock Dissolved material remains in the ξ loop. To render all released substances harmless.

The above-described amount of dissolved material is left on the fiberboard.

Hot press after mechanically squeezing the pack water to 60% dryness The fiberboard in operation holds approximately 5200kf of water to be evaporated and removed. Therefore, Nonotsu Water has 2452 or more dissolved substances per 5200 kt of water. can be held at a rate of 4.5 cm. The solution flowing down into the container 56 is 104 00kf of water and 400kf of emitted material, an amount that the chip normally absorbs. Possible limit, i.e. usually more than 5oooh water for 8000kw chip. There are many things that never happen. Therefore, 2400 kf of water is steamed in the cooling tower 64. For this purpose, the solution must be preheated. Do this preheating with Cyclone 16? This is carried out using steam taken out through the pipe 14a. 2400k in cooling tower 64 Water of f is evaporated as a gas mixture of steam and air. air by fan 68 supplied. After this evaporation, the remaining solution μ% s o o oh water and 400 rings The soluble material is pumped into the impregnating container 24 via the tube 26. Ta.

400 rings of released woody material were thus restrained within the loop during demolition &24 By confining 5kf in a 7-ainode, the total amount of emitted wood material is eliminated. can be harmful. Water μ pad at 5200 ℃ evaporated in hot press for 2 hours. Replace with water supplied to the quarter cycle. It is necessary to drain the water. Not at all.

45 of the dissolved organic matter in the pack water is maintained at a sufficiently close level to To prevent discoloration of the phi/z-board unit during the removal process. Furthermore, squeezed All of the extracted wood water has been made harmless.

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Claims (1)

[Claims] 1. Chips of 1 piece of cellulose-containing material are placed under high pressure in a high-temperature saturated steam atmosphere. Preheat, defibrate under atmospheric or high pressure, and suspend the defibrated material in pack water. To form a wet sheet, make an OA suspension and add the wet sheet. Closed cloth is compressed under heat to dehydrate it, and the squeezed water is returned through a suspension process. In a method for producing 7-inode ζ-I-de by a wet method using the Nonotsu Water method, The fibers obtained in the fibrillation process are mechanically dehydrated, and the resulting fibers are also processed in a fibrillation process. Impregnating the chip before the preheating process with an aqueous solution containing released organic substances. A method for manufacturing fiberboard using a wet method, characterized by: 2. Organic matter released during the defibration process after steaming and compressing the chips and 1. mechanical dehydration. The material is compressed and pressed into the impregnated liquid and expanded in the impregnated liquid to absorb the liquid. Claim 1, characterized in that the chip is impregnated by How to put it on. 3. The pulp of the dehydration stage contains an amount of O-releasing organic material suitable for subsequent processing steps. Claim 1 or 2, characterized in that a large amount of water is added to the defibration nozzle. The method described in section. 4. Add gr to the mizupo pack quarter cycle produced during the chip compression process. A method according to claim 3, characterized in that: 5. By evaporating the aqueous liquid obtained by squeezing, a suitable water content for impregnation is obtained. According to any one of claims 1 to 4, the method is characterized in that a solution for impregnation is obtained. Method described.