JPS62169041A - Physical property measuring apparatus for planar material - Google Patents

Abstract

PURPOSE:To eliminate mechanically mobile parts of a microwave measuring sensor, by fixing a pair of microwave hollow resonators to be positioned on both sides of an planar object to be measured at more than one points to measure the amount of water. CONSTITUTION:A paper 1 as an object to be measured is supplied from a paper making machine and moves forward at a speed of about 1,000m per min as shown by the arrow. A pair of reentrant type microwave hollow resonators 2 as microwave measuring sensor are build as couple one on the upper surface and the other on the lower surface and in total, six microwave hollow resonators 2 are arranged in an array within one block (about 1m long). The block thus obtained is arranged securely across the width of the paper 1 in the number corresponding to the width of the paper 1. The microwave hollow resonator 2 is made up of a microwave transmitting/receiving section, a cylindrical hollow section provided with a cylindrical convex and a plate which covers it as opposed thereto with the paper 1 inserted thereinto.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses microwaves to electronically measure the chemical or physical properties of an object to be measured, by measuring data from measurement sensors fixed in spots. It is related to the device.

[Conventional technology]

Measuring devices using microwaves have been undergoing further improvements in recent years, reflecting advances in data processing technology and device technology in the field of microelectronics.

In particular, devices that online measure the moisture content or basis weight (weight per unit area) of paper during the papermaking process are an application field that is attracting attention. In the paper manufacturing process,
By feeding these factors online to processes such as valve raw material adjustment and drying control,
Efforts have been made to keep the final quality of the paper constant. Also,
Since the price of paper at a paper mill is determined by the weight per unit of the product at the time of shipment, online measurement of water content, in particular, is one of the most important issues in the paper manufacturing process.

A typical technique for measuring water content, basis weight, etc. using microwaves is to mount one microwave measurement sensor 2 on a frame 3 and mechanically reciprocate it, as shown in Figure 4A. This is a method of measuring while moving. In this case, due to the relative relationship between the paper flow direction and the paper width direction, measurement is actually performed in a zigzag pattern diagonally with respect to the paper as shown in FIG. 4B. Paper machines in the paper manufacturing process are becoming faster and faster.
Paper making speeds of 1000 m/min have also been put into practical use.

On the other hand, the moving speed on the frame of the microwave measurement sensor in FIG. 4A is at most [per second], O
It is generally about cm. Width 6m, paper making speed 100
In the case of 0 m, it takes about 2 minutes for the microwave measurement sensor to move back and forth over the frame, and during this time it measures about 2000 m of paper once in a diagonal direction.

[Problem that the invention seeks to solve]

The conventional measurement of water content or basis weight in the papermaking process using microwaves has the following problems.

The first problem is that the measurement area is diagonal to the paper in a zigzag pattern, making it impossible to measure any specified position or fixed area in the width direction, which is essential for controlling the quality of the paper. This is in fact impossible. In the paper manufacturing process, online measurement information regarding moisture content or basis weight on all surface areas of paper is required, but this is extremely difficult with conventional techniques.

The second problem is that the conventional method requires a frame to move or run the microwave measurement sensor precisely, but the structure of this frame is extremely complex in terms of accuracy, resulting in significant cost and maintenance. It also has the disadvantage that it takes too much time and effort for inspection. Since microwave measurement sensors are generally non-contact and transmission type, it is necessary to keep the relative distance or relative position of the pair of upper and lower microwave measurement sensors constant at all times. For this reason, the frame on which the microwave measurement sensor is mounted requires many efforts to improve accuracy from the time of design and manufacture, making it extremely expensive. The reality is that even after installation, it is a huge amount of work to maintain accuracy, check for mechanical wear or deterioration of running belts, running cables, etc., and maintain them.

[Means to solve the problem]

The present invention solves the above problems by using a configuration in which a pair of microwave cavity resonators located on both sides of a planar measurement object are provided and fixed at at least two locations. An example of a specific configuration is shown in FIG. 1 A, B, and C.
This is a measuring device in which microwave cavity resonators are arranged and fixed in an array in the width direction of the paper, which is opposite to the paper flow direction of the paper machine. Using each microwave cavity resonator, the moisture content, basis weight, etc. of any designated position or fixed area in the width direction of the paper are measured online by electronic scanning control.

[Effect]

The measuring device according to the present invention is characterized in that a pair of microwave measurement sensors are provided and fixed to at least two or more required measurement sites in advance, so that the mechanical Since there are no moving parts, on-line measurement accuracy is significantly improved, and at the same time, the cost of the entire measuring device is significantly reduced.

In the conventional online measurement of water content or basis weight in the papermaking process, a pair of microwave measurement sensors mounted on a frame is used to measure in a diagonal zigzag pattern as shown in Figure 4B with respect to the paper surface. It was common.

Although it was theoretically possible to install two or more microwave measurement sensors and perform measurements in a fixed manner, practical implementation has been slow because - microwave measurement sensors are expensive and have a significantly large volume. Ta. The measuring device according to the present invention is a microwave measuring sensor which is significantly smaller, weighs and is simpler than the conventional technology which has a diameter of 5 cm and a height of 41 mm as shown in FIG. 60 years - 263874
It became possible to put it into practical use for the first time by using The microwave cavity resonator shown in FIG. 5A is conventionally known as an endrunt type cavity resonator. By providing the convex portion inside the cavity, the Q value of the microwave is significantly increased, and the electric field density is locally increased, resulting in a stable, compact, and highly accurate measuring device. These small microwave measurement sensors are arranged in an array in the paper width direction during the papermaking process, and by electronically controlling each microwave measurement sensor, the amount of moisture at any position on the paper at any time can be measured online. Alternatively, it becomes possible to measure basis weight, etc.

- For example, by placing the required number of microwave measurement sensors across the width of the paper and scanning it electronically,
-In an instant, all data in the width direction of the paper can be obtained online. Data that could not be measured using conventional frame-moving mechanical actuation data collection is obtained. One specific method of electronic scanning is that for each transmitting section attached to each microwave cavity resonator, one common micro transmits the microwaves sent from the transmitting section to the attenuator of each transmitting section. By voltage control, scan transmission and reception is performed from the first resonator to the last resonator in order. If the characteristics of each resonator when there is no object to be measured are memorized and adjusted in advance using a method such as voltage control using a microcomputer, then
The individual characteristics of each resonator can be made uniform very easily.

The measuring device according to the present invention is a device that adopts a method in which a plurality of macro-fine cavity resonators are fixed and a measurement part G of a measured object to be measured is set in advance, and in particular, In online measurement of paper moisture content, basis weight, etc. in the papermaking process, paper surface information can be obtained continuously online.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. Figure 1 shows
1 is an embodiment of a typical fixed-type physical property measuring device for planar materials according to the present invention. Paper 1 on the paper machine moves forward in the direction of the arrow at a speed of about 1000 m/min. The papermaking speed is not particularly limited, and even if it is sufficiently slow, stationary, or sufficiently slower, the measurement will not be affected. A pair of glue-endrunt type microwave cavity resonators 2 are fixed to the top and bottom of the girder 1. The specific shape of the pair of glue-endrunt type microwave cavity resonators 2 is shown in FIG. 5A. In FIG. 5A, reference numeral 1 denotes a wire 1 as an example of the object 1 to be measured. Further, each microwave cavity resonator 2 in the lower pair is composed of an upper and lower pair, and a cylindrical cavity portion provided with a cylindrical convex portion is arranged at the lower part of FIG. 5A.

Its upper part shows a plate covering the lower cavity in the form of inserting the gill 1 oppositely. As an example of a specific shape, the material is aluminum, the radius of the hollow cylinder is 2.54c3, the depth of the hollow cylinder is 2.99cm, the radius of the convex cylinder is 0.90cm,
The distance between the tip of the convex portion and the upper plate was 1.35 cm. In this case, the microwave resonance frequency is 2.7Gtlz, Q
The value is 7097, and the half value of the Q value is 380 KHz with a peak at 2.7 GHz, which is significantly sharper than the conventional Q value of 173. Therefore, the accuracy of measuring moisture content, basis weight, etc. is significantly improved.

In the embodiment shown in FIG. 1, six of the glue-endrant type microwave cavity teacher devices 2 are arranged in an array in a block about 1 m long. In FIG. 1, the cavity portion of the microwave cavity resonator is constructed of aluminum having a length of 1 m, and has six cylindrical cavities in common, each having a cylindrical convex portion inside.

On the other hand, the upper plate facing the cavity is composed of an aluminum plate having a length of 1 m and common to each microwave cavity resonator. In this way, by commonly arranging about 6 microwave cavity resonators in each 1 m long block, we can create a fixed system with several block configurations corresponding to the paper, which is an example of the object to be measured. Measurements are taken.

There are no particular restrictions on the numerical values such as the size of the shape and the number of cavities listed here, and they may be freely selected and designed depending on the object to be measured. In the embodiment shown in FIG. 1, although the microwave transmitter is not specified, for example, each of the above
By using a scheme in which one microwave transmitter is provided for each m-long block to commonly supply microwaves to each micromeasuring cavity, costs are significantly reduced. Online electronic scan control or calibration for individual measurements of each microwave cavity in each block can be freely configured according to the measurement purpose using many existing electronic technologies. . The embodiment of the present invention shown in FIG. 1 shows the physical arrangement of an apparatus in which a required number of microwave resonators are arranged in an array and fixed to an object to be measured. The method of arranging each microwave cavity with respect to the object to be measured is not only by arranging them in a straight line as shown in Fig.
They may be arranged in a staggered manner, or if a specific area is to be measured intensively, several methods may be arranged around one location. In any case, the feature of the present invention is that the microwave cavity resonators are provided and fixed at two or more locations, thereby eliminating mechanical movement related to measurement. This type of system is extremely natural and easily envisioned, but with conventional technology, individual microwave cavity resonators cannot be made small, lightweight, and inexpensive as described above, so it is difficult to design in practical terms. It was impossible.

A second embodiment of the invention is shown in FIG.

Figure 2 shows that, as shown in Figure 5B, each microwave measurement sensor has a structure in which cavities with convex portions are placed opposite each other on multiple sides with the object to be measured in between. As such, the width of the paper as the object to be measured is arranged on the array. The only difference from FIG. 1 is that the individual microwave cavity resonators have been changed from FIG. 5A to FIG. 5B.

A third embodiment of the invention is shown in FIG.

FIG. 3, like the second previous embodiment, consists of individual microwave cavities modified from FIG. 5A to FIG. 5C. FIG. 5C shows a conventional box-type microwave cavity resonator.

In any of the embodiments, the individual microwave cavity resonators may have any shape and are fixed to the object to be measured in at least two locations, and measurements may be performed using existing electronically controlled scanning. This is a major feature.

〔Effect of the invention〕

The effects of the fixed physical property measuring device for flat materials according to the present invention can be summarized in the following three items.

(1) Fixed type total scan Since the object to be measured is a flat material, especially paper that moves at high speed in the paper manufacturing process, it is now possible to measure the moisture content or basis weight of all paper surfaces using a fixed method. . By placing micro-target sensors in advance in predetermined areas of the object to be measured, all necessary area information is provided online.

(2) Improving measurement accuracy Due to fixed measurement, there are no mechanical or physical moving parts in each microwave measurement sensor.1. Errors related to measurement have been significantly reduced, and it has become possible to measure moisture content or basis weight, etc., which is necessary and sufficient for the papermaking process, with high accuracy and reliability.

(3) Reducing device design and manufacturing costs Since the device is of a fixed type, there are no mechanically moving parts, the effort required for accuracy such as positioning is reduced, and the number of parts can be reduced without reducing the number of parts. Therefore, the design of the entire device has become easier, and furthermore, manufacturing costs and maintenance and inspection costs have been significantly reduced.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a fixed type physical property measuring device for planar materials according to the present invention. FIG. 2 is a diagram showing another embodiment 1 of the present invention. FIG. 3 is a diagram showing another embodiment 2 of the present invention. FIG. 4A is a diagram showing a conventional example. FIG. 4B is a diagram showing the measurement site measured in FIG. 4A. FIG. 5A is a diagram showing a pair of microwave measurement sensors used in the conventional example and the present invention. FIG. 5B is a diagram similar to FIG. 5A showing another pair of micro-measuring sensors. Similar to FIG. 5A, FIG. 5C is a diagram showing yet another pair of micro-microwave measurement sensors. 1, --1ffi 2. -1 microwave measurement sensor 3, -1 frame 4, -1 measurement site 5, -1 microwave transmitting/receiving unit Patent applicant Masao Sawada, patent attorney representing Dipol Co., Ltd. Microwave measurement sensor Fig. 5 C 1, Paper 2, microwave measurement sensor-5, microwave transmitter/receiver

Claims (1)

[Claims] An apparatus for measuring physical properties of a planar material, in which a pair of microwave cavity resonators located on both sides of a planar object to be measured are fixed to at least two measurement sites.