JPH0894548A - Water content control device of paper manufacturing plant - Google Patents

Abstract

PURPOSE: To enhance plant efficiency by using a water content measuring device which calculates the water content of wood chips from the amount of transmitted radiation, taking measurements continuously in a short time, and automatically controlling steam used in cooking process. CONSTITUTION: In a device for controlling the water content of wood chips 1 during a paper manufacturing process, a radiation source 2 (neutron rays) is embedded in one wall surface of a box-shaped container 4 open at its top and closed or open at its bottom; and in the opposite wall surface are a water content measuring device 3 provided with a detector for measuring the amount of transmitted radiation; a computing element for indicating the flow rate of steam in accordance with an output of the water content measuring device 3; and an automatic flow rate controller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a papermaking plant which can detect the water content of a wood chip for papermaking and automatically control the steam flow rate to measure and control the water content of earth and sand, cement and other powders. The present invention relates to a moisture control device.

[0002]

2. Description of the Related Art To produce pulp in a paper mill, fiber cells are isolated by eluting an intermediate layer composed of lignin that strongly adheres fibers to each other, and at the same time, lignin and non-fibers existing in the cell membrane are isolated. It is necessary to remove carbohydrates and special components of wood to collect soft fibers, and for this purpose steaming is performed. That is, in this steaming, the steamed chemical is put in a steaming pot and wood chips are heated with steam. The degree of wetness of the wood chips at this time, that is, the amount of water has a great influence on the amounts of the chemical and steam used. Therefore, conventionally, the water content of the wood chips is measured in advance and the steam content is manually operated. This conventional moisture measuring device uses a drying oven 5 to measure the amount of moisture as shown in FIG. 6, but this takes a long time to dry the wood chips 1, and it takes about one day for each measurement. Was.

[0003]

Generally, wood chips are piled up outdoors, and even if the water content changes depending on the weather conditions, it takes about one day to measure the water content as described above. It was difficult to finely control the amount used. Further, since the amount of steam used is controlled manually, there is a drawback that the steam is wasted. The present invention is intended to solve the above-mentioned conventional problems, in which the moisture content of a wood chip is measured from the amount of radiation transmitted, the moisture content is measured in a short time and continuously, and the steam used in the cooking step is used. The present invention aims to provide a moisture control device for a papermaking plant, which can automatically control the above to improve the thermal efficiency of the plant.

[0004]

Therefore, the present invention is an apparatus for controlling the water content of wood chips in a papermaking process, in which a radiation source (neutrons) is provided on one wall surface of a box-shaped container having an open top surface and a closed or open bottom surface. Line) is embedded, and a moisture measuring device having a detector for measuring the amount of radiation transmission on the wall surface opposite to this, a calculator for instructing the steam flow rate based on the output of the moisture measuring device, and a flow rate automatic control device Further, a belt conveyor is provided below the box-shaped container of the bottom opening, and the wood chips loaded from above the container are mounted on the belt conveyor and carried out, and further A radiation source is fixed to the front surface of the moisture measuring device in the box-shaped container, which serves as means for solving the problem.

[0005]

The moisture measuring apparatus of the present invention utilizes radiation, of which the density of a substance is measured by γ rays and the moisture is measured by neutron rays. The fast neutrons emitted from the radiation source collide with the atomic nuclei that make up the substance, and the neutrons are randomly scattered in all directions. At each collision, the neutron loses some kinetic energy and becomes thermal neutron. The density of thermal neutrons created in this material is significantly higher for hydrogen atoms than for other elements. That is, the density of thermal neutrons created in a substance is determined by the density of hydrogen atoms contained in the substance.

In the present invention, the number of hydrogen atoms contained in a unit volume is measured and expressed as the mass of water. Neutron rays are measured by a thermal neutron detector and γ rays are measured by a γ ray detector. The amount of water calculated by the CPU is digitally displayed. In the wood chips, a large amount of hydrogen atoms as organic substances exist in addition to hydrogen atoms as so-called free water. Therefore, the amount of water can be measured by calibrating the amount of hydrogen atoms other than water according to the material of the wood chip and correcting the measured hydrogen concentration. The moisture control device of the papermaking plant of the present invention is installed in the distribution line of wood chips to continuously detect the amount of moisture, calculate this as the amount of steam, and enter the steamer while automatically controlling the optimum amount of steam. To do.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described with reference to the embodiments of the drawings. FIG. 1 is an embodiment of a moisture control apparatus for a papermaking plant according to the present invention, FIG. 2 is a detailed sectional view, and FIG. FIG. 4 is a state diagram showing another embodiment attached, FIG.
Is a partial cross-sectional view obtained by adding a radiation source 2a to FIG.
Is a wood chip, 2 and 2a are radiation sources, 3 is a moisture measuring device, 4 is a box-shaped container, 6 is a γ-ray detector, 7 is a thermal neutron detector, 8 is a CPU, 9 is a digital display, and 10 is a hopper tank. , 11 is a belt conveyor, and 14 is a radiation source support rod. Now, in FIG. 1, the radiation source 2 is embedded in the center of the left inner wall of the box-shaped container 4, and the radiation source 2 is embedded in the inner wall of the opposing surface.
As shown in FIG. 3, the moisture measuring device 3 is fixed so that the surfaces of the γ-ray detector 6 and the thermal neutron detector 7 are in direct contact with the wood chip 1. When measuring the water content, the wood chip 1 is put in the box-shaped container 4, and the water content measuring device 3 is operated to measure the water content. Since the measurement by the water content measuring device 3 is a short-time measurement, not only the batch-like measurement in which the wood chips 1 are put into and taken out from the container as described above, but also the measurement is continuously performed in the distribution line. Is also possible.

In FIG. 3, a moisture measuring device 3 is provided on the side wall of a hopper tank 10 which is another embodiment of the present invention, and the radiation source 2 is fixed to the front surfaces of detectors 6 and 7 (not shown) of the moisture measuring device 3. Thus, the support rod 14 is provided. Further, in FIG. 4, a radiation source 2 a is provided in addition to the radiation source 2 on the opposite wall surfaces of the moisture measuring device 3. 3 and 4, the wood chips 1 are loaded into the hopper tank 10 from above, and the wood chips 1 are mounted and moved on the belt conveyor 11 from below. However, since the hopper tank 10 has a large capacity, it is almost stationary near the moisture measuring device 3. Therefore, by using this device capable of speedy measurement, it can be applied as continuous measurement and can be sufficiently measured even in the middle of the flow passage. Further, as shown in FIG. 5, the output of the moisture measuring device 3 is calculated by the calculator 21 for the optimum amount of steam, and the steam flow rate is controlled by the automatic controller 24. The shape of the hopper tank 10 is not limited to the shape shown in FIG. 3 and may be another shape. In addition, by using this device, it is possible to measure and control the water content of soil, cement, etc.

[0009]

As described in detail above, according to the present invention, the water content can be measured continuously and speedily. Further, since the amount of steam used is automatically controlled in the steaming process, the thermal efficiency is improved. Further, since it is automated, the number of manual operations is reduced, and the cost can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a side sectional view of a moisture measuring apparatus for a paper manufacturing plant according to a first embodiment of the present invention.

FIG. 2 is a detailed side sectional view showing a moisture measuring procedure in the apparatus of FIG.

FIG. 3 is a view showing a state in which the device of the present invention is attached to a hopper tank.
It is a perspective view of the Example different from.

FIG. 4 is a side sectional view of a moisture measuring device showing an embodiment different from FIG.

FIG. 5 is a block diagram showing steps of a paper manufacturing plant.

FIG. 6 is a cross-sectional view showing a moisture measuring apparatus of a conventional paper manufacturing plant.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wood chip 2, 2a Radiation source 3 Moisture measuring device 4 Box container 6 γ-ray detector 7 Thermal neutron detector 10 Hopper tank 11 Belt conveyor 12 γ-ray 13 Neutron beam 14 Support rod 21 Computing unit 24 Flow rate automatic control device 25 Steaming Kettle

Claims (4)

[Claims] 1. A device for controlling water content of a wood chip in a papermaking process, wherein a radiation source (neutron beam) is buried in one wall surface of a box-shaped container having an open top surface and a closed or open bottom surface, which opposes it. A paper manufacturing apparatus comprising a water content measuring device provided with a detector for measuring a radiation transmission amount on a wall surface, a calculator for instructing a steam flow rate based on an output of the water content measuring device, and an automatic flow rate control device. Moisture control equipment for plants. 2. The belt conveyor is provided below the box-shaped container having the bottom opening, and the wood chips loaded from above the container are loaded on the belt conveyor and carried out. Moisture control equipment for paper manufacturing plants. 3. The water content control apparatus for a paper manufacturing plant according to claim 1, wherein a radiation source is fixed to the front surface of the water content measurement apparatus in the box-shaped container. 4. A device for controlling water content of wood chips in a papermaking process, wherein a radiation source (neutron beam) is fixed in a box-shaped container having an upper surface opened and a lower surface closed or opened, and one side facing the radiation source. A water content measuring device having a detector for measuring a radiation transmission amount on one wall, a calculator for instructing a vapor flow rate based on an output of the water content measuring device, and a flow rate automatic control device. A water control device for a paper manufacturing plant.