JPH0621010Y2 - Moisture measuring device for granulation, coating, drying, etc. - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to granulation and coating of a fluidized bed, for example.
The present invention relates to a moisture measuring device used for drying or the like.

[Conventional technology]

For example, in the fluidized bed granulation method, air is fed from below the raw material granules put in the granulation tank, the raw material is raised by this air flow and the raw material is dropped by the weight of the raised raw material. Moves up and down so that the raw material powder is so-called fluidized, and a binder is further sprayed to bond and agglomerate the powder to obtain a powder.

In such a granulation method, the particle size and the like of the formed granules differ depending on the amount of water such as the binder. That is, if the water content is large, the powder adheres to each other or to the surface of the powder and the bonding is promoted, so that the powder having a relatively large particle size is obtained. A powder having a relatively small particle size can be obtained because there is little bonding between the powders and adhesion of the powder to the powder surface, and the bonded material is easily decomposed.

Thus, the measurement of the water content during granulation in the granulation method,
This is one of the important operations for obtaining the desired granulated product, and it is possible to control the spray amount of binder, the supply amount of air, the air temperature, etc. to appropriate values based on the measured water content. Therefore, a desired granulated product can be obtained.

Further, such measurement of the water content and control based on the measured value are important in coating, drying and the like.

However, heretofore, there has been no suitable method for measuring the amount of water, so that the measurement of the amount of water and the control by it have hardly been performed.

Even if it is done, it predicts the amount of water in the granulation tank based on the measurement of temperature or humidity in the exhaust gas. Accurate measurement of quantity was almost impossible.

Recently, there is a method to measure the water content by extracting the granules during granulation, but it is necessary to extract a small amount of granules during granulation and return it after the measurement. No
The operation is cumbersome and continuous measurement of water content is impossible.

Further, a method is known in which an observation window is provided on the side wall of the granulation tank, and measurement is performed through this window by using an optical means or the like. According to this method, continuous measurement is possible. However, there is a drawback that powder particles adhere to the inner surface of the window and measurement becomes impossible.

In order to eliminate this defect, an observation tube protruding from the granulation tank is provided, a water content measuring device is installed at the tip of the observation tube, and air is blown into the granulation tank from this observation tube to observe the granular material. It is known that the inside of the cylinder is prevented from coming particularly near the measuring window of the measuring device.

This method eliminates the drawbacks such as the powder or the powder adhering to the observation window of the measuring device which makes measurement impossible, and enables continuous measurement control. However, if the air for preventing the adherence of the granular material enters the granulating layer and the flow rate is not large, the effect of preventing the adherence cannot be obtained. For example, the fluidized state of the fluidized bed is disturbed and a good granulating action is performed. There is a drawback that can not be kept.

[Problems to be solved by the device]

The present invention uses an infrared moisture meter and arranges the infrared detection window in the part where moisture is to be detected in the granulation tank, and the infrared detection window is installed in the detection window without using a means that affects the granulation such as a large air flow. It is an object of the present invention to provide a moisture measuring device which can measure the moisture content continuously even when the powder grains are in contact with each other without the adhesion of the powder grains.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the moisture measuring device of the present invention is provided with an optical fiber in an infrared moisture meter, and by arranging its tip at a position where moisture should be measured, light (absorption wavelength by moisture is specified (Infrared of wavelength) is introduced to the moisture meter to enable measurement, and by providing a means for supplying hot air to the tip of the fiber, even if the tip of the fiber is installed in any atmosphere, the Measurement is possible and continuous measurement is possible. Therefore, the device of the present invention was used for various granulations using, for example, a fluidized bed granulation method, a tumbling granulation method, etc., and for measuring the water content of powders and granules during coating, drying, etc. In this case, it is possible to continuously carry out the direct water content measurement at the measuring point without powder or powder adhering to the tip of the optical fiber. Therefore, by using this, the amount of water (binder) sprayed,
Good granulation, coating and drying are possible by controlling the amount of air and air temperature.

As described above, in the moisture measuring device of the present invention, the tip of the optical fiber can be arranged at any position by transmitting the measuring light to the detecting part by the optical fiber, and the position to be measured can be freely selected. Since a means for supplying hot air to the tip of the optical fiber is provided in this, the detection light emitting portion and the detected light incident portion at the tip are heated by the hot air and dried to prevent the adherence of powder particles. Since continuous measurement is possible, it is possible to control the amount of water in the granules during the processes such as granulation, coating and drying. That is, by using the optical fiber type moisture meter, only the tip of the optical fiber, which is the emission end surface and the incident end surface of the measurement light, need only be arranged at the measurement point, so that the measurement point is not limited.

〔Example〕

Next, an example in which the moisture measuring device of the present invention is installed and used in a rolling granulation device using a perforated rotary plate will be shown as an example.

FIG. 1 is a cross-sectional view of a granulating apparatus equipped with the moisture measuring device of the present invention, and FIG. 2 is an enlarged cross-sectional view of the tip portion of the moisture measuring device.

In FIG. 1, 1 is a granulating tank, 2 is a perforated rotary plate, 3 is a binder spraying nozzle, 4 is a hot air supply port, and these are known rolling granulators, which have been introduced. The raw material 5 is rolled by the rotation of the perforated rotary plate, and the air flow from below is supplied through the perforated rotary plate, so that the raw material becomes a swirling flow accompanied by rolling including the movement as shown by the arrow. Here, granulation is performed by spraying the binder from the nozzle 3.

Reference numeral 10 denotes an optical fiber type infrared moisture measuring device having a tip end having a structure as shown in FIG. 2, which is arranged near the perforated rotary plate 2 of the granulating device of FIG.

FIG. 2 shows another example of the structure of the fiber tip of the moisture measuring apparatus of the present invention, in which the tip is heated by hot air. That is, 11 is an optical fiber on the light emitting side, and 12 is an optical fiber on the light receiving side, which are connected to the main body of the moisture meter. 15 is a hot air supply pipe. This moisture measuring device uses an optical fiber 11 on the light emitting side to emit infrared rays (light having an absorption wavelength due to moisture), which is the measuring light emitted from the main body.
The amount of water is measured by transmitting the light from the tip of the optical fiber 12 and transmitting it to the main body. Here, the tip end of the optical fiber is heated by hot air passing through the supply pipe 15 to prevent the powder particles from adhering. Since the hot air sent through this supply pipe is for heating, its flow rate is small, and therefore this hot air affects the air flow and the flow of powder and granules in the processes of forming, coating and drying. There is nothing to give this out. On the other hand, by adjusting the flow velocity of this hot air to an appropriate value, it is possible to skip the particles located at the tip of the optical fiber without causing the above-mentioned air flow and the flow of particles to be measured. Especially preferred.

In the above-mentioned embodiment, if the tip portion of the moisture meter is arranged so as to be inclined according to the direction of rotation (direction of the arrow) of the perforated rotary plate as shown in FIG. The granular material is always taken away, which is preferable for measurement. If the tip of the optical fiber is made rotatable so that the tilt angle can be changed, the most desirable tilt angle can be obtained according to the rotation speed and rotation direction of the rotary plate and other conditions.

In the above embodiment, the tip of the optical fiber of the moisture meter is fixed to the granulation tank so that it is located above the perforated rotary plate, but the present invention is not limited to this, and it can be installed at any place. is there. For example, in a fluidized bed granulating apparatus or the like in which a net is horizontally stretched in the granulating tank, by installing an optical fiber tip so that the end face faces upward in this net, the end face becomes a granular material. It is possible to place them in contact. Further, it can be fixed to the fixed plate in a granulating device such as agitation granulator equipped with the fixed plate.

Also, the rolling granulator using the perforated rotary plate as the granulator has been explained, but it has already been described that it can be applied and is effective for moisture measurement in other granulators such as a fluidized bed granulator. Is.

[Effect of device]

According to the device of the present invention, since it is of the optical fiber type, any place can be selected as a measuring point and continuous measurement is possible because there is no adhesion of powdery particles or the like to the tip. Therefore, it is possible to measure with the tip of the optical fiber in contact with the granular material during the granulation, coating, and drying steps, so that the moisture content of the granular material can be measured directly and accurately or continuously. Measurement becomes possible, and optimal control for granulation, coating, drying, etc. can be performed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment in which the device of the present invention is applied to a rolling granulator, and FIG. 2 is a cross-sectional view showing the configuration of the tip of a moisture meter used in the device of the present invention. FIG. 3 is a horizontal sectional view of the device of FIG. 1 ... Granulating tank, 2 ... Perforated rotating plate, 3 ... Binder spray nozzle, 4 ... Warm air supply port, 10 ... Moisture meter, 11, 12 ...
… Optical fiber, 15… Hot air supply tube.

Claims (1)

[Scope of utility model registration request] 1. A method for measuring the water content of a powder or granular material during steps such as granulation, coating, and drying, which comprises a moisture meter and a measuring light and a detection light transmission connected to the moisture meter. And a hot air supply pipe having at least a tip portion arranged side by side with the optical fiber and opening toward the tip of the optical fiber, and at least the tip of the optical fiber is located at a position where the tip surface can contact the granular material. A water content measuring device characterized in that parts are arranged.