JP2759820B2 - Moisture detector in fluidized bed processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fluidized bed processing apparatus for fluidizing powder or granules, forming a fluidized bed, and performing drying, granulation, heat treatment and the like. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared absorption type moisture detecting device for continuously detecting, in a non-contact manner, the moisture of a granular material flowing in a room.

[Prior Art] FIG. 2 shows, for example, JP-A-62-52435 and JP-A-62-951.
1 schematically shows a configuration of a conventional moisture detecting device described in Japanese Patent Publication No. 25-205. In the figure, 1 is a fluidized bed processing device,
Reference numeral 2 denotes a fluidizing chamber in which a powdery substance 3 to be measured 3 is caused to flow by hot air blown up from a lower hot air chamber 4 through a porous plate 5. Reference numeral 6 denotes a detection tube attached to an appropriate position on the peripheral wall of the flow chamber 2 in a communicating state, and a seal glass 7 is provided at an upper end opposite to the attachment end thereof.
An infrared absorption moisture meter 8 for measuring the moisture of the object 3 in the flow chamber 2 via the seal glass 7 is attached. An air supply pipe 9 as an air supply means is provided in the detection cylinder 6.
And, if necessary, a second air supply pipe 10 is provided.
By feeding an appropriate amount of air into the flow chamber 2 through the inside, the granular material 3 is prevented from entering the detection cylinder 6 and accumulating.

FIG. 3 is a diagram showing the internal structure of the infrared absorption type moisture meter 8, wherein 11 is a moisture meter main body, 12 is a light projecting conduit, and its base end is a filter wheel 14 which is rotated by a motor 13. The light projecting portion 12a at the other end is fixed to the center of the transmission glass 16 so as to be located on the center axis of the seal glass 7 and the detection tube 6. A plurality of filters 15 are arranged on the same circumference of the filter wheel 14 in order to selectively extract light of a specific wavelength. 17 is a light source lamp, 18 and 19 are convex lenses for projecting light, 20 is a reflecting mirror provided at a bent portion of the conduit 12 for projecting light, and 21 is for condensing light reflected from the DUT 3 on the light receiving element 22. Is a convex lens for receiving light, 23 is an amplifier for an optical signal by the light receiving element 22, and 24 is a signal converter for transmitting these signals to an external arithmetic and display device.

In the moisture detecting device configured as described above, light having a wavelength that is absorbed by water (absorption wavelength light) and light having a wavelength that is not easily absorbed by water (comparative wavelength light) are selectively applied by a plurality of filters 15. Take out, and from the light emitting conduit 12, seal glass 7,
Light is alternately projected onto the measured object 3 in the flow chamber 2 through the detection tube 6. The reflected light from the DUT 3 passes through the seal glass 7 and the transmission glass 16 and is collected by the convex lens 21,
Received. Then, after this light receiving signal is amplified by the amplifier 23, it is transmitted to an external arithmetic and display unit via the signal converting unit 24, and calculates the ratio of the reflected light of the absorption wavelength light and the reflected light of the comparison wavelength light to obtain the water content. The output having a correlation with is extracted, converted into a moisture value and displayed. Thereby, the water content of the powder 3 in the fluidized state can be continuously measured in a non-contact manner.

Note that an air supply pipe 9 and a second
Since an appropriate amount of air is sent from the air supply pipe 10 of the above, it is possible to prevent the granular material 3 from entering the detection cylinder 6 and adhering to the surface of the seal glass 7 or accumulating at the lower part of the detection cylinder 6. Yes, removing obstacles to moisture measurement.

[Problem to be Solved by the Invention] The conventional moisture detecting device is configured as described above, and a space is provided between the tip of the light projecting portion of the light projecting conduit 12 and the seal glass 7. . Therefore, a part of the light is reflected on the surface of the seal glass 7, and the reflected light B
Of the moisture meter 8 with respect to the minute change of the reflected light A, which causes the S / N ratio to be relatively deteriorated. Depending on the delicate variation of the mounting angle of the seal glass 7, the S / N ratio may range from about 1/2 to an unmeasurable state in some cases.

On the other hand, in a batch-type apparatus for removing the product by removing the fluid chamber 2 from the fluidized bed processing apparatus 1 together with the perforated plate 5, the moisture meter 8 needs to be detachable from the detection tube 6, and In fluidized bed processing of materials such as foods, the inside of the processing apparatus is visually inspected through the seal glass 7 during operation in order to clean the inside of the processing apparatus for each batch or adjust the amount of air blown to the detection tube. For this reason, the moisture meter 8 is required to have a detachable configuration. For this reason, the tip of the light projecting portion 12a and the seal glass 7 are not fixed and are provided with a certain gap, but the gap causes the above-described problem.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a moisture detecting device that shields reflected light from a sealing glass surface from light reflected from an object to be measured.

[Means for Solving the Problems] In order to achieve the above object, a moisture detection device according to the present invention is held between a light emitting unit and a seal glass such that a tip thereof is in contact with the seal glass, A light-shielding cylinder is provided, which is entirely or partially made of a soft material such as rubber, for shielding light reflected by the sealing glass from light reflected from the object to be measured.

Further, in order to reduce light reflected by the seal glass, it is preferable to use quartz glass having an antireflection coating applied to the seal glass.

[Operation] In the present invention, the light-projecting portion is extended by the light-shielding cylinder, and the tip of the light-projecting portion is lightly in contact with the seal glass surface. Is not superimposed on the reflected light. Therefore, a decrease in the sensitivity of the moisture meter is prevented, the S / N ratio is improved, and accurate moisture measurement becomes possible.

In addition, if a seal glass made of quartz glass with an anti-reflection coating is used, the reflection itself of the projected light can be reduced and the amount of transmitted light can be increased, so that the measurement accuracy can be further improved.

Since the light-shielding cylinder described above is entirely or partially made of a soft material such as rubber, it does not damage the seal glass surface or change the mounting angle of the seal glass when the moisture meter is attached or detached.

Example An example of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a moisture detecting device according to the present invention, and FIG.
3 and 3 indicate the same parts. In FIG. 1, reference numeral 25 denotes a light shielding tube, which is formed from a rubber tube. One end of the light-shielding tube 25 is inserted and held on the outer periphery of the light projecting portion 12a. In addition, the tip of the light shielding unit 25 is set in a state of lightly contacting the surface of the seal glass 7 when the moisture meter 8 is attached to the detection tube 6.

Therefore, if the moisture meter 8 is configured in this manner, the reflected light B of the light emitted from the seal glass 7 does not go out of the light shielding tube 25, and is not superimposed on the reflected light A from the object 3. Also, about 90% of the projected light passes through the seal glass 7, and in the case of the seal glass 7 made of quartz glass coated with an anti-reflection coating, the amount of light transmitted through the seal glass can be increased to about 99%. As a result of the above,
The S / N ratio of the moisture meter 8 is improved, and accurate moisture measurement can be performed.

The light-shielding cylinder 25 is made of a soft material such as rubber, and its tip is only lightly in contact with the seal glass 7.
When attaching / detaching the moisture meter 8, the sealing glass surface is not damaged, and the mounting angle is not changed.

[Effects of the Invention] As described above, according to the present invention, the light reflected from the seal glass is measured by providing the light-shielding cylinder, which is entirely or partially made of a soft material, between the light emitting part and the seal glass. By using a seal glass with an anti-reflective coating to shield from reflected light from objects,
The effect of improving the S / N ratio and enabling high-precision moisture measurement is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a moisture detection device according to the present invention, FIG. 2 is a schematic configuration diagram of a conventional moisture detection device,
FIG. 3 is an internal configuration diagram of the infrared moisture meter of FIG. DESCRIPTION OF SYMBOLS 1 ... Fluidized bed processing apparatus 2 ... Fluid chamber 3 ... Measured object 6 ... Detection cylinder 7 ... Seal glass 8 ... Infrared absorption type moisture meter 9 ... Air supply pipe 10 ... Second air supply pipe 12 … Light-emitting conduit 12a …… Light-emitting part 25 …… Light-shielding tube

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-62-52435 (JP, A) JP-A-61-138528 (JP, A) JP-A-61-4947 (JP, A) JP-A 52-524 148194 (JP, A) Japanese Utility Model Showa 62-22543 (JP, U)

Claims (2)

(57) [Claims] 1. A detecting cylinder provided on a peripheral wall of a fluidizing chamber of a fluidized bed processing apparatus, an air supply means for supplying an appropriate amount of air through the detecting cylinder to the fluidizing chamber, and a mounting end of the detecting cylinder. Moisture detector comprising a seal glass provided at an end opposite to the above, and a reflection type infrared absorption moisture meter mounted on the seal glass and measuring the moisture of the object in the fluidized chamber through the seal glass. In the device, between the light emitting part of the infrared absorption type moisture meter and the seal glass, all or a part of which a tip is held to be in contact with the seal glass is made of a soft material, and A water detecting device in a fluidized bed processing apparatus, further comprising a light shielding cylinder for shielding light reflected by a seal glass due to light projection from light reflected from an object to be measured. 2. The sealing glass according to claim 1, wherein said sealing glass is quartz glass provided with an anti-reflection coating.
A moisture detector in the fluidized bed processing apparatus according to the above.