JP2762362B2 - Separation treatment method for papermaking - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a new pulp production treatment, a broke treatment or a newspaper,
In waste paper processing of magazines, etc.
The present invention relates to a papermaking separation method for a papermaking screen for rejection processing in which defibrated pieces are disintegrated from papermaking raw materials including stones, plastic pieces, styrene pieces, and vinyl pieces) and foreign substances are discarded outside the system.

[Conventional technology]

Generally, papermaking equipment such as new pulp production processing, waste paper processing, waste paper processing, disintegrates the defibrated fragments in the fiber suspension that is the raw material, and removes foreign matter such as stone, sand, metal fragments, resin fragments, etc. In order to eliminate dust, a screen device is used which is formed by partitioning the inside of a closed casing with a screen plate having a large number of round holes or slits, and an impeller which rotates at high speed to disintegrate the screen tail in combination with this screen device. There is known a high-speed disintegrator equipped with.

If you reject process by using the screen device, conventionally deployed and round hole screen device S ₁ and slit screen device S ₂ in series to the main line A as shown in FIG. 5 (A) (B), round hole screen tail and slit screen tail and each separate disintegrator respectively B, After macerating at B _1, chest respectively C, C ₁ and pump D, a circular hole tail through D ₁ screen apparatus S ₃ and the slit tail is treated with a screen device S ₄ (FIG. 5 (a)) or, alternatively round hole screen device S ₁ and joins together both screen tail the slit screen unit S ₂ disintegrator at chest C and pump D After sending to B and disaggregating, chest C ₁
And treatment with a slit tail screen device S ₄ After roughing a round hole tail screen apparatus S ₃ via pump D ₁ (FIG. 5 (B)) is performed.

[Problems to be solved by the invention]

However, in this conventional processing system, foreign matter in each screen tail is easily miniaturized by a high-speed disintegrator, and the processing system becomes complicated and expensive. In addition, a round hole tail screen device, a hydrofoil of a slit tail screen device, That is, foreign matter is applied to the agitator, causing operation troubles, and many foreign matter returning to the screen device is also undesirable because it causes clogging of the screen, and the separation function is reduced, so the pump capacity must be increased. On the other hand, in the case of the single treatment using only the tail screen device, there is a problem that the disintegrated fragments are discharged as cake and the yield is deteriorated.

The present invention is intended to properly eliminate these conventional disadvantages, it is possible to increase the processing capacity for selective separation of useful fibers and foreign matter, and furthermore, the discharge of disintegrated fragments is small,
Foreign materials are not crushed as high-speed disintegrators improve the product quality, and the operation and operation time of the disintegration function can be adjusted according to the amount and properties of the defibrated pieces in the raw material, and the degree of foreign matter crushing can also be adjusted. It is an object of the present invention to provide an operation method capable of greatly improving the recovery of useful fibers in an inexpensive form.

[Means for solving the problem]

The present invention includes a step of disintegrating the remaining undisintegrated pieces during a water filling step and a raw material passing operation step, when disintegrating a screen tail from a round hole screen device and a slit screen device in a closed casing having a screen, Each operation of supplying the raw material and washing water to the casing and discharging the coarse foreign matter, fine foreign matter, and useful fibers for selection is performed by opening and closing a control valve provided in each flow path. Priority is given to the detection of whether the timer or the load or the pressure difference between the inlet and outlet of the raw material has come first, and the process is shifted to the defibration process of the remaining undisintegrated pieces, the useful fiber collection and washing process, the coarse foreign material discharge process, and the fine foreign material And a discharging process are sequentially performed, and each process is continuously operated for a predetermined time by a timer.
The raw material passing operation process, raw material supply and selected raw material discharge,
Opening a control valve that circulates the entire amount of effluent including the undisintegrated fiber to the raw material supply path, and continuing the operation while closing and suspending the control valve for other supply and discharge operations, the residual undisintegration In the piece disintegration process, while circulating a part of the waste liquid containing fine foreign matter to the raw material supply path, adjusting the throttle opening of the control valve so as to discharge a part of the selected raw material, other supply and discharge operations are performed. The operation is continued while the control valve is closed and stopped.

[Action]

The operation of the present invention will be described with reference to FIG. 1. The raw material supplied into the closed casing 2 of the separating device is composed of an impeller 5 rotating close to the screen 1 and a disintegrating stirring blade facing the impeller 5. In step 8, the fibers are disturbed in the pretreatment chamber 3 and flow through the useful fibers from the screen 1, and the foreign matter is separated without passing through the screen 1, and is removed from the lead-out path 7 to the outside of the pretreatment chamber 3 for processing. . On the pre-processing chamber 3 side of the screen 1, an impeller 5 that rotates while approaching the screen surface to wipe it, and a stirring blade 8 that rotates at a high speed at the center opposite to the impeller 5 are provided. The raw material fed into 3 is given a swirl and a vortex in the direction of rotation, and the resulting centrifugal force causes coarse foreign substances in the raw material to fly to the outer peripheral wall of the pretreatment chamber 3 and to be drawn out while rotating the peripheral wall. Road
Eliminated by intermittent opening and closing of the 14 control valve V ₄ of SueHanare Kaihen維分passing through one of the screen 1 with useful fibers are separated by a screen bucket 9 in the swirling flow of the post-processing chamber 4, outlet 10 together they are derived in a more opening and closing of the control valve V ₆ of the discharge flow channel 16, a portion necessary control valve V ₅ in the circulation flow path 15
Is returned to the raw material flow path 11 for reprocessing. Further, the useful fibers that have passed through the screen bucket 9 are passed through the selected material outlet 12
Although ₁ than in off control of the control valve V ₂ of the channel 12 is intended to be processed by the retrieved next step out of the system, the raw material through the inlet of the timer or load or starting material during the operation process to the closed casing 2 Priority is given to the detection of the pressure difference at the outlet, whichever comes first, and the process is shifted to the disintegration process of the residual disintegrated fragments, and the useful fiber collection and washing process, the coarse foreign material discharging process and the fine foreign material discharging process are sequentially performed. Can be operated continuously for a predetermined time by a timer to improve the disintegration function, enhance the function of separating foreign substances, and also reduce the pump capacity for supplying the raw material, thereby significantly reducing the running cost.

〔Example〕

To illustrate embodiments of the present invention in the first to fourth illustrated example, the screen 1 of the screen tail than round hole screen device S ₁ and slit screen device S ₂ on the main line A of the papermaking material through the chest C and pump D Into the closed casing 2 having a gap. That is, the raw material flow path 11 with a control valve V ₁
The screen 1 for separating the raw material introduced from the papermaking raw material inlet 6 into useful fibers and foreign matter of impurities is divided into a pre-processing chamber 3 and a post-processing chamber 4 in a closed casing 2. A separation mechanism in which a rotary impeller 5 is provided in the pre-processing chamber 3 in the vicinity of the screen 1 and an outlet channel 14 connected to a discharge port 7 for the large foreign matter separated by the separation mechanism. In the apparatus provided with the above, a disintegrating agitating blade 8 for disturbing the swirl flow and the vortex generated in the pretreatment chamber 3 is disposed in the pretreatment chamber 3 so as to face the rotary impeller 5, and the swirl flow with stirring the spiral, to form a selective material outlet 12 ₁ and the fine foreign matter discharge port 10 which communicates respectively with the flow paths 12, 16 with a control valve V _2, V ₆ to the post-processing chamber 4, and the pretreatment paper cleaning water supply channel 13 with a control valve V ₃ to the chamber 3 deployed communication There is a separation device.

In this case, the agitating blade 8 for disaggregation has a smaller diameter, for example, 1/3 of the diameter of the rotary impeller 5, and a higher speed, for example, 1000 m.
A driving mechanism that is reversely rotated at the speed of ~ 3000 rpm or the same rotation or intermittently reversely rotated, for example, provided with a motor 18, may be selectively operated only for the entire process continuous or only for the final disintegration fragment disintegration process, and the like. The processing chamber 4 is provided with a cylindrical screen bucket 9, which is divided into a selected raw material collecting chamber 19 and a fine foreign matter collecting chamber 20, and is provided with an agitator wheel 21 which moves along the cylindrical screen bucket 9.

The screen 1 provided in the closed casing 2 is preferably of a double separator type in which a round hole strainer is used and the screen basket 9 is combined as a slit screen.

Further, the papermaking raw material is supplied to the closed casing 2 from the tangential direction to generate a swirling flow, and the operations of supplying the raw material and the washing water and discharging the coarse foreign matter, the fine foreign matter, and the selected raw material are performed in each flow path. This is performed by opening and closing control valves V _{1 to} V ₆ provided in 11, 12, 13, 14, _{15, and 16} , and the closed casing 2 is provided with an exhaust passage 17 having an air release valve V ₇ , Manual valves V ₈ and V ₉ are attached to the flow paths 11 and 12,
The control valves V ₁ ~V ₇ repeats the opening and closing operation as in the first table,
Separation processing is performed.

That is, the raw material passing operation process is started after the screen is filled with water, and the useful fiber is continuously drawn out from the flow channel 12. However, the timer or the load or the pressure difference between the inlet and the outlet of the raw material, whichever comes first, is detected with priority. After the disintegration process of the residual powder, the process of collecting and washing the selected raw materials for the useful fiber, the process of discharging the coarse foreign particles, and the process of discharging the fine foreign particles including the finely separated fragments are sequentially performed. Continue driving.

For example, foreign substances in the raw material cannot be passed through the screen 1 and are gradually concentrated in the casing 2, so that the passage of the high quality raw material to the outlet is hindered. Load the timer or a motor, or the differential pressure of the doorway is being preset control valve V ₁ of the inlet valve is closed, the washing water is introduced into the casing 2, the outlet quality fibers remaining in the casing 2 Collect on the side. After being collected good quality fiber, the casing is Hai棄foreign matter out of the system by fully opening the valve V ₆ of the reject valve becomes only water and foreign objects. All these actions are automatically controlled and unmanned.

In the step of disaggregating the residual disintegrated fragments, a part of the waste liquid containing the residual disintegrated fragments is passed through the raw material supply flow path 11 or directly circulated to the pretreatment chamber 3 while a part of the selected raw material is disintegrated. a throttle opening degree of the control valve V _2, V ₅ for discharging the other supply and discharge operation or continuous operation by rest closes the control valve _{V 1, V 3, V 4} , V 6, V 7, wherein In the raw material passing operation process, the control valves V ₁ , V ₂ , and V ₅ for supplying the raw material, discharging the selected raw material, and circulating the entire amount of the waste liquid including the fine foreign substance to the raw material supply path are opened. The control valves V ₃ , V ₄ , V ₆ , and V ₇ may be closed and stopped for continuous operation.

Further, the agitator foil 21 is provided with a rotating impeller 5.
Along with the rotation of the motor 18 controlled by the motor 24 via the rotation shaft 22 and the pulley 23, for example, 300
Although it is configured to be driven at ~ 800 rpm, it may be linked by a single motor via a speed change or speed increasing mechanism or a clutch mechanism, and furthermore, each control valve V _{1 to} V ₇ and each detection The unit and the timer are communicated to a computer unit (not shown) of the data processing unit to form a control circuit.
Internally fixed data in the computer unit including A / D converter and D / A converter that inputs the data of disintegration conditions such as raw material processing amount, raw material concentration, raw material concentration, inlet / outlet pressure difference, load, etc. as analog signals and converts them into digital signals the input data comparison process and controls the motor for driving the rotating impeller 5 and the stirring blade 8, and controls the opening and closing of the control valve V ₁ ~V ₇ and, operating while the digital display continuously display unit It is better to do it.

In the figure, T is a timer, Hp is a load, Δp is a differential pressure, and 25 is a base.

〔The invention's effect〕

According to the present invention, in a raw material passing operation step, a control valve for supplying a raw material, discharging a selected raw material, and circulating a whole amount of a waste liquid including an undisintegrated fiber to a raw material supply path is opened, and other supply and discharge operations are controlled. Close the valve and keep it running while continuing to stop,
In the disintegration process of the remaining undisintegrated pieces, while circulating a part of the waste liquid containing fine foreign matter to the raw material supply path, adjusting the throttle opening of the control valve so as to discharge a part of the selected raw material, Since the discharge operation was continued while the control valve was closed and stopped, the recovery rate of useful fibers could be greatly increased, the degree of foreign matter crushing could be adjusted, and the product quality could be improved. . In addition, since it is possible to accurately separate not only coarse foreign matter but also fine refuse, the defibration ability is increased, the selective processing capacity for separating useful fibers and foreign matter is improved, and metal fragments and stones mixed in the raw material are improved. , Other foreign matter, etc. can be accurately and efficiently separated. In addition, the operation and operation time of the disintegration function can be adjusted according to the amount and properties of the undisintegrated pieces in the raw material, and the degree of foreign matter crushing can also be adjusted.
The screen tail processing system can be simplified, and efficient screen work can be realized.

[Brief description of the drawings]

1 is a longitudinal side view of an embodiment of the present invention, FIG. 2 is a sectional plan view taken along line II of FIG. 1, FIG.
FIG. 4 is a flow chart of a processing step, and FIGS. 5A and 5B are system diagrams of a conventional example in use. DESCRIPTION OF SYMBOLS 1 ... Screen, 2 ... Casing, 3 ... Pre-processing chamber, 4 ... Post-processing chamber, 5 ... Impeller, 6 ... Inlet, 7
... Foreign matter outlet, 8 ... stirring blade, 9 ... screen bucket, 10 ... discharge port, 11, 12, 13, 14, 15, 16, 17 ... flow path, 1
8,24 ...... motor, V ₁ ~V ₇ ...... control valve.

Claims (1)

(57) [Claims] When the screen tail from a round hole screen device and a slit screen device is defibrated in a closed casing having a screen, the method includes a defibration step of remaining undisintegrated pieces during a water filling step and a raw material passing operation step, Each operation of supplying the raw material and the washing water to the closed casing and discharging the coarse foreign matter, the fine foreign matter, and the selected useful fiber is performed by opening and closing a control valve provided in each flow path. Priority is given to the detection of whether the timer or the load or the pressure difference between the inlet and outlet of the raw material has come first, and the process is shifted to the defibration process of the remaining undisintegrated pieces, the useful fiber collection / cleaning process, the coarse foreign matter discharge process and the fine And a foreign matter discharging step. The method for separating paper for papermaking, in which each step is continuously performed by a timer for a predetermined time, In the process, raw material supply and selected raw material discharge,
Opening a control valve that circulates the entire amount of drainage including the undisintegrated fiber to the raw material supply path, and continuing the other supply and discharge operations while closing and suspending the control valve to continue the operation. In the piece disintegration process, while circulating a part of the waste liquid containing fine foreign matter to the raw material supply path, adjusting the throttle opening of the control valve so as to discharge a part of the selected raw material, other supply and discharge operations are performed. A separation method for papermaking, wherein the operation is continued while the control valve is closed and stopped.