JP3065836B2 - Dewatered cake moisture content measuring method and dehydrated cake moisture content measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the control of a dewatering process for dewatering sludge generated from sewage, night soil or industrial wastewater treatment facilities by a belt press dewatering machine, and the post-treatment of dewatered cake obtained in the dewatering process. The present invention relates to a method for measuring the moisture content of a dehydrated cake and a device for measuring the moisture content of a dehydrated cake, which measure the moisture content of the dehydrated cake using an infrared moisture meter.

[0002]

Conventionally, when the solid-liquid separation of sludge in the base Rutopuresu type dehydrator, after agglutination add an appropriate amount of polymer flocculant to sludge, travels aggregation sludge horizontal or substantially horizontal filtration The sludge sandwiched between the filter cloths is supplied to the cloth to perform gravity dehydration, and the sludge sandwiched between the filter cloths is run between a plurality of rolls to apply a pressing force due to the tension pressure of the filter cloth to perform the press dewatering, and sometimes the sludge is sandwiched in the final step A high squeezing force due to the tension of the pressure belt is applied from the upper part of the filter cloth to squeeze and dewater, and the dewatered cake is discharged through these dewatering steps.

[0003] The amount of water contained in the dewatered cake, that is, the water content of the dewatered cake, has an important effect on the next process such as incineration or landfill of the dewatered cake. In other words, the amount of fuel used during incineration and the cost of transportation and the volume of the landfill during landfill are affected. It was desired to be discharged at a rate.

Therefore, means for measuring the water content of the dewatered cake has been proposed. One example is a method in which a small amount of a dehydrated cake is collected, dried with a dryer adjusted to a constant temperature until a constant weight is obtained, a weight difference before and after drying is measured, and a water content is calculated. This method requires several hours or more in drying time, and thus has a drawback in that it is not possible to quickly respond to control of the dehydration step.

In another example, an infrared moisture meter is installed on a belt conveyor that conveys the dehydrated cake to an incinerator or a landfill site, and the level of the dehydrated cake on the belt conveyor is adjusted by a leveling mechanism. There is a method of measuring a moisture value in a non-contact manner with an infrared moisture meter while preventing scattering of incident light and reflected light. Although this method has an advantage that a measured value can be obtained in real time, it has the following problems because it is an indirect measuring method based on the absorbance of infrared rays by moisture.

That is, in the case of sludge generated from sewage, human waste, or industrial wastewater treatment facilities, several types of sludge are generated by the treatment process, and the amount of sludge sent to the dewatering treatment process is different for each type, and is the same. The amount varies depending on the time even in the type. For this reason, the properties of the dehydrated cake obtained in the dehydration step often change constantly, and the difference in the properties of the dehydrated cake affects the infrared absorbance, making it difficult to obtain a correct measurement value.

[0007]

SUMMARY OF THE INVENTION The present invention relates to the use of an infrared moisture meter to facilitate post-treatment management or control of the dewatering process of dewatered cake of sludge generated from sewage, night soil or industrial wastewater treatment facilities. It is an object of the present invention to immediately measure the moisture content of a dewatered cake and reduce a measurement error.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a method for measuring the water content of a dewatered cake according to the present invention is a method for measuring the water content of a dewatered cake discharged from a belt press type dewatering machine. A method for measuring the water content of a cake, wherein the inclination and cutoff of the calibration curve of the infrared moisture meter for a plurality of types of dehydrated cakes having different mixing ratios of digested sludge and raw sludge.
The pieces and the information of the variation are stored, and using a color difference meter and an infrared moisture meter disposed near the dewatering cake outlet of the belt press type dewatering machine so as to face the dewatered cake discharged from the dewatering cake outlet, The infrared moisture meter to the belt
The dewatering is performed by reciprocating in the width direction of the filter cloth of the press dehydrator.
The infrared absorbance of the cake is measured, and the slope of the calibration curve of the infrared moisture meter corresponding to the color information output by the color difference meter and the slope are cut off.
The calibration curve of the infrared moisture meter was set based on the pieces and the information of the variation, and the moisture content of the dehydrated cake was measured with the infrared moisture meter based on the calibration curve of the set infrared moisture meter. It is characterized by the following.

The dewatered cake moisture content measuring device of the present invention is provided near a dewatered cake outlet of a belt press type dewatering machine so as to face a dewatered cake discharged from the dewatered cake outlet. the belt press type de color difference meter for measuring the color of the dehydrated cake to be discharged, with facing the dehydrated cake discharged from dehydration cake outlet near dehydrated cake outlet of the belt press dewatering machine from
Are filter cloth reciprocably disposed in the width direction of the fountains, and an infrared moisture meter for measuring the infrared absorbance <br/> of dehydrated cake discharged from the dehydration cake outlet, the mixing of the digested sludge and raw sludge Storage means for storing information on the inclination, intercept, and variation of the calibration curve of the infrared moisture meter for a plurality of types of dehydrated cakes having different ratios, and corresponding to the color information output from the color difference meter. a calibration curve setting means of an infrared moisture meter for setting the calibration curve of the infrared moisture meter on the basis of the slope and intercept and variations in information search <br/> amount line of infrared moisture meter is stored in the storage means, It is characterized by having.

[0010]

According to the method for measuring the moisture content of a dehydrated cake or the apparatus for measuring the moisture content of a dehydrated cake of the present invention, the color of the dehydrated cake to be measured is measured by a color difference meter, and the color information output by the color difference meter is obtained. , the slope of the calibration curve of infrared moisture meter for dehydrated cake of a plurality of types having different mixing ratios of the digested sludge and raw sludge
The calibration curve of the infrared moisture meter is set based on the information of the intercept and the variation, and the moisture content of the dehydrated cake to be measured is measured by the infrared moisture meter in which the calibration curve of the infrared moisture meter is set. Since the dewatered cake is flat near the outlet of the dewatered cake of the belt press type dewatering machine in which the infrared moisture meter and the color difference meter are provided, the fluctuation of the measurement distance is small, and the measurement error can be further reduced. Of et al., Infrared moisture meter
Can reciprocate in the width direction of the filter cloth of the belt press dehydrator
The average of the moisture content in the width direction of the dewatered cake
By obtaining the value, the actual moisture content can be ascertained.

The calibration curve in the infrared moisture meter is a curve (or a straight line) showing the correlation between the infrared absorbance of the object to be measured and the measured moisture content. The infrared absorbance of the dewatered cake correlates with the mixing ratio of digested sludge and raw sludge which is the basis of the dewatered cake. Also, as will be described later ,
The mixing ratio between digested sludge and raw sludge correlates with the lightness of the color information obtained by the color difference meter. Therefore, an appropriate calibration curve of the infrared moisture meter in the infrared moisture meter can be set based on the brightness.

[0012]

FIG. 1 is a schematic view showing an embodiment in which the method for measuring the water content of a dewatered cake and the apparatus for measuring the water content of a dewatered cake according to the present invention are applied to a belt press type dehydrator, and FIG. It is a block diagram of a moisture content measuring device.

The belt press type dewatering machine 1 is provided with a liquid-permeable endless first filter cloth 11 and a second filter cloth 12.
The filter cloth 11 and the second filter cloth 12 are looped around a number of rollers and form a loop in a state where they are tensioned by the filter cloth tensioning devices 13a and 13b, respectively. And the first filter cloth 1
The 1st and 2nd filter cloths 12 are each run in the direction of the arrow in the figure, and perform dehydration treatment on sewage, human waste, or sludge generated from industrial wastewater treatment facilities as follows.

That is, the sludge and the coagulant are sufficiently mixed and reacted in the coagulation mixing tank 14, and the coagulated sludge 10 is supplied onto the first filter cloth 11 in the natural dewatering section to relatively desorb the coagulated sludge. The easy water is dehydrated by gravity, and the desorbed liquid is received by the pan 15a and discharged to the outside. On the other hand, the first filter cloth 11 is reversed by the reversing roll 16a to drop the coagulated sludge 10 onto the second filter cloth 12 in the natural dewatering section, and the second filter cloth also dewaters relatively easily desorbed water by gravity. The desorbed liquid is received by the pan 15b and discharged to the outside.

After passing through the natural dewatering section for dewatering water by the above-mentioned gravity, the coagulated sludge is removed from the first filter cloth 11 and the second filter cloth 12.
, And wrapped around a large number of rolls 16 b, and furthermore, squeezed and dewatered by a squeezing and dewatering unit using a pressure belt 17 to form a dewatered cake S between the first filter cloth 11 and the second filter cloth 12.

Then, the first filter cloth 11 and the second filter cloth 12 are separated by reversing rolls 16c and 16d.
The first and second filter cloths 12 are washed with water by filter cloth cleaning devices 18a and 18b, respectively, and are fed toward a natural dewatering unit.

In this embodiment, a belt press type dehydrator 1
An infrared moisture meter 2 is provided at the outlet of the dehydrated cake while being held by a moving mechanism 3, and a color difference meter 4 is provided in front of the infrared moisture meter 2. Then, the color of the dehydrated cake S discharged from the outlet of the dehydrated cake is measured by the color difference meter 4 and the infrared absorbance of the dehydrated cake S is measured by the infrared moisture meter 2.

[0018] Then, as shown in FIG. 2, the absorbance signal of infrared rays outputted from the color signal and the infrared moisture meter 2 output from the color difference meter 4 each controller 41,
Is input to the data processing device 5 through 21, the data processing unit 5 sets the calibration curve of infrared moisture meter for use with an infrared moisture meter 2 on the basis of the information stored in advance and a color signal, the infrared moisture The infrared absorption signal is converted into a moisture content signal based on the calibration curve of the meter and output.

The infrared moisture meter 2 is held at a fixed distance from the second filter cloth 12 by the moving mechanism 3 near the outlet of the dewatered cake, and the moving mechanism 3 moves the infrared moisture meter 2 in the width direction of the second filter cloth 12 (filter). Direction perpendicular to the running direction of the cloth)
Is reciprocated.

FIG. 7 is a front view of a mounting portion of the infrared moisture meter 2 and the moving mechanism 3, FIG. 8 is a plan view thereof, and FIG. 9 is a side view thereof. The moving mechanism 3 includes a pair of left and right L-shaped fixed arms 31.
L, 31R, which is fixed to the frame 1A at the outlet end of the dewatering cake of the belt press type dewatering machine 1, and is attached to the horizontal frame 32 which is stretched over the fixed arms 31L, 31R.
A parallel slide shaft 33 is provided. The slide shaft 33 is mounted at a right angle to the traveling direction of the second filter cloth 12 (parallel to the reversing roll 16d), and holds the moving block 34 slidably in the width direction of the second filter cloth 12.

A motor 35 capable of normal and reverse rotation is disposed at one upper end of the horizontal frame 32, and a sprocket 36 is disposed at the other end. A driving sprocket 35a mounted on a driving shaft of the motor 35 A chain 37 is hung between the and the sprocket 36, and one portion of the chain 37 is fixed to the moving block 34.

The infrared moisture meter 2 is fixed to the moving block 34 with its measuring head 2a facing the second filter cloth 12 and the reversing roll 16d. Note that the cable 2b of the infrared moisture meter 2 is wound around a horizontal bar 38 laid parallel to the horizontal frame 32, and the end thereof is connected to the controller 21 in FIG.

With the above configuration, the moving block 34 and the infrared moisture meter 2 are kept at a fixed distance from the second filter cloth 12 by the driving of the motor 35, and are in a direction perpendicular to the running direction of the second filter cloth 12. Is reciprocated. The motor 35
Is controlled by a motor controller (not shown), and a limit switch (not shown) attached near both ends of the slide shaft 33 detects the moving block 34 and switches the moving direction.

The rotation speed of the motor 35 is controlled in accordance with the operation speed of the belt press type dehydrator 1, and the infrared moisture meter 2 is reciprocated at a speed synchronized with the travel speed of the second filter cloth 12. The moisture content (moisture value) of the dehydrated cake S on the second filter cloth 12 is measured by the moisture meter 2.

In the vicinity of the dewatering cake outlet of the belt press dewatering machine 1, the dewatering cake (mechanism of the compression dewatering unit) of the belt press dewatering machine 1 discharges the dewatered cake in a sheet shape. The surface becomes smooth. The dewatered cake by the belt press type dewatering machine is a method in which the coagulated sludge dispersed almost uniformly in the width direction of the filter cloth is sandwiched between two filter cloths and is wrapped around a large number of rolls to be dewatered. The surface is formed into a flat plate and discharged.

The filter cloth wrapped around the belt press type dehydrator is usually tensioned by an air cylinder, and has a structure capable of withstanding sludge supply up to the stroke length limit of the cylinder. When sludge longer than the stroke length of the cylinder is supplied, it exceeds the cushion limit of the cylinder, and thereafter, the filter cloth is broken. Therefore, some countermeasures are usually taken so that the height of the gravity dewatering section falls within a certain range.

For this reason, the dewatered cake discharged from the belt press dewatering machine has a flat surface and its thickness is slightly different depending on the properties of the sludge to be dewatered. It falls within the range of about ± 3 mm.

[0028] Thus, the distance of the surface of the freshly or infrared moisture meter 2 and dehydrated cake surface of dehydrated cake becomes smooth is also kept substantially constant, without providing a leveling mechanism, by infrared moisture meter 2 The measurement error of the moisture value is reduced. In addition, since a non-contact infrared moisture meter is used, the moisture content of the dehydrated cake can be measured instantaneously.

By the way, in the belt press type dewatering machine, as the length of the filter cloth used in the width direction increases, the width of the dewatering property, that is, the water content of the dewatered cake is more distributed due to the dewatering mechanism. . For example, as shown in FIG. 10, as an example, a measurement position in the width direction and a measurement result of the water content of a belt press type dehydrator having a filter cloth width of 3 m are shown. Occurs.

[0030] However, according to the above KiSo location, since infrared moisture meter 2 filter cloth has become reciprocally movable in the widthwise direction (second filter cloth 12), dehydrated cake in the width direction of the filter cloth By obtaining the average value of the water content of the dehydrated cake, the actual water content of the dehydrated cake can be grasped.

According to the apparatus of the above embodiment, the speed of the motor 35 is controlled by the controller and the filter of the infrared moisture Since the moving speed of the cloth in the width direction can be synchronized with the speed of the filter cloth, an average value of the running distance of the filter cloth in the width direction can be easily obtained.

Next, in setting the calibration curve of the infrared moisture meter in the embodiment, first, the relationship between the sludge and the calibration curve of the infrared moisture meter will be described. 4 was measured using an infrared moisture meter for samples of sludge in certain wastewater treatment plants is a diagram showing an example of measurement results of the absorbance and the absolute dry moisture content of the infrared moisture meter (measured moisture content).

The measurement conditions were as follows: sample (A) containing only digested sludge;
For the sample (B), which is a mixed sludge of digested sludge and raw sludge, and the sample (C) containing only raw sludge, the operating conditions of the belt press type dehydrator 1 (sludge supply amount, coagulant addition rate, coagulation mixing tank rotation speed, The filter cloth speed was changed to set a low moisture content to a high moisture content of the dehydrated cake, and the infrared absorbance and the absolute dry moisture value were sampled. In addition,
In the figure, the same sample with a different mark is different in the measurement date and the operating condition of the belt press type dehydrator, but the type of sludge and the mixing ratio are constant.

As can be seen from FIG. 4, in each sample, red
There is a high correlation between the absorbance of the outside line and the absolute dry moisture value.
The above equations are summarized as follows for reference. (A): y _A = 67.18 + 72.72x _A , γ = 0.
_{88 (B): y B =} 65.75 + 65.66x B, γ = 0.
91 (C): y _C = 64.55 + 55.79x _C , γ = 0.
93 where x _A , x _B , and x _C are infrared absorbances, y _A , y
_B and y _C are absolutely dry moisture values, and γ is one of the indicators of variation.
That is the correlation coefficient.

As described above, since there is a high correlation for each sample, these equations are used to calculate the infrared water for each sample.
It can be used as a calibration curve for the spectrometer, but if the sample is different, that is, if the properties of the dehydrated cake are different, the infrared moisture meter
It can be seen that the calibration curve of FIG. Also this red
The deviation of the calibration curve of the external moisture meter indicates the intercept (0-order coefficient) and the slope (1) of the calibration curve of the infrared moisture meter as the ratio of raw sludge increases.
It can be seen that the second order coefficient) appears smaller.

On the other hand, the present inventor measured the color of the dehydrated cake using a color difference meter, and analyzed the organic matter content (VTS), which is one of the component indices of the measured dehydrated cake. As a result, the results shown in FIGS. 5 and 6 were obtained.

FIG. 5 shows a case of digested sludge, and FIG. 6 shows an example of a case where raw sludge is mixed into digested sludge, and the content ratio of digested sludge is gradually reduced so that only sludge is finally obtained. . Also in this figure, the horizontal axis represents the sampling point (time), and the vertical axis represents the VTS change rate when each of the first measurement values is 1.
The lightness L of the three elements L, a ^* and b ^* by the color difference meter is used.
The values are displayed together.

As shown in FIGS. 5 and 6, in the case of digested sludge, VTS and L value hardly change, but as shown in FIG. 6, raw sludge starts to be mixed into digested sludge, and the ratio of raw sludge gradually increases. It can be seen that as the value increases, the VTS value also increases, and the L value also increases at a similar rate. That is, it was found that the mixture ratio of digested sludge and raw sludge can be detected by reading the L value with a color difference meter.

Therefore, in the above embodiment, in the data processing device 5 (FIG. 2), the lightness L value of the color signal output from the color difference meter 4 and the infrared moisture stored in the memory 5a are stored.
Infrared water based on the data of the calibration curve of the meter to set the calibration curve of infrared moisture meter suitable for properties of dehydrated cake, the infrared absorbance signal outputted from the infrared moisture meter 2 was set above
The water content is converted into a water content based on the calibration curve of the spectrometer and the water content data is output.

FIG. 3 is a functional block diagram of the data processing device 5. Next, data processing such as setting of a calibration line of the infrared moisture meter will be described with reference to FIG. Note that the data processing device 5 is configured by a microcomputer or the like, and realizes each function of FIG. 3 by performing processing based on a control program stored in a program memory (not shown).

First, the color difference meter 4 is operated by the function of the block B1.
, The raw data (lightness L value) is taken in at a predetermined sampling cycle, the raw data is filtered in block B2 to remove noise components, and the operation for identifying sludge properties based on the lightness L value is performed in block B3. Then, in block B4, it is determined whether or not to change the calibration curve of the infrared moisture meter according to the current sludge property.

For example, sludge properties (mixing of digested sludge and raw sludge)
In the case where the ratio does not change and the calibration curve of the infrared moisture meter does not need to be changed, the blocks B3 and B4
Is repeated to determine whether or not the hold time for holding the calibration curve of the infrared moisture meter has elapsed, and if it has elapsed, the brightness L value and the data of the calibration curve of the infrared moisture meter are determined in block B5. Determine the calibration curve of the infrared moisture meter based on
The zero-order coefficient a ₀ and the first-order coefficient a ₁ of the calibration curve of infrared moisture meter set at block B11.

The determination of the calibration curve of the infrared moisture meter in block B5 is performed, for example, as follows. As described with reference to FIGS. 4 to 6, the sludge properties (digested sludge and raw sludge
Coefficients a ₀ and a of the calibration curve of the infrared moisture meter suitable for the mixing ratio)
₁ has a constant relationship close to linear with respect to the ratio of raw sludge, and the ratio of raw sludge has a constant relationship with the lightness L value. Therefore, for example, the coefficients a ₀ and a of the calibration curve of the infrared moisture meter in FIG.
The data of the relational expression between ₁ and the lightness L value is stored in the memory 5a as the data of the calibration curve of the infrared moisture meter, and based on the lightness L value and this relational expression in block B5, the infrared moisture meter is used. The coefficients a ₀ and a ₁ of the calibration curve are obtained, and the calibration curve of the infrared moisture meter is determined.

In the process of block B5, the equation of the calibration curve of the infrared moisture meter shown in FIG. 4 (coefficients a ₀ and a ₁ ) or the intermediate equation between the calibration curves of the infrared moisture meter and the brightness L value are used. Is stored in a table or the like, and the calibration curve of the infrared moisture meter is determined by selecting appropriate coefficients a ₀ and a ₁ of the calibration curve of the infrared moisture meter from the current lightness L value. It may be.

On the other hand, the raw data (absorbance signal) is taken in from the infrared moisture meter 2 by the function of the block B6, the raw data is filtered in the block B7 to remove noise components, and the invalid data is cut in the block B8. and averages the infrared absorbance data on the basis of a predetermined sampling data corresponding to the moving position of the infrared moisture meter 2 in block B9. In block B10, the dehydration cake is detected by a sensor or the like (not shown) provided in the belt press dehydrator 1, and when the dehydration cake is detected, invalid data is cut in block B8.

Then, in block B11, the infrared absorbance data averaged in block B9 is converted into a water content based on the calibration curve of the currently set infrared moisture meter, and the water content is output to the outside in block B12. I do. In addition,
This moisture content is output to the personal computer 6 or the like,
Data collection and analysis of the water content are performed by the personal computer 6 or the like.

[0047]

【The invention's effect】 According to the present invention as described above,
The moisture content of the dewatered cake obtained by solid-liquid separation of the mud
To measure with a moisture meter, the mixing ratio of digested sludge and raw sludge
Infrared moisture analyzer for different types of dewatered cakes
Store the slope, intercept and variation information of the calibration curve,
The color of the dehydrated cake to be measured is measured and this color information
At least the brightness information and the slope of the calibration curve of the infrared moisture meter
Calibration of infrared moisture meter based on section and variation information
Set the line and near the dewatering cake outlet of the belt press dewatering machine
Beside the dewatered cake discharged from the dewatered cake outlet
To be arranged Using a color difference meter and infrared moisture meter.
In addition, the infrared moisture meter of the filter cloth of the belt press type dehydrator
Move back and forth in the width direction to measure the infrared absorbance of the dehydrated cake.
The digested sludge and raw sludge of the dewatered cake
Water content by the appropriate calibration curve of the infrared moisture meter according to the mixing ratio of
Instantaneously measure the moisture content of the dehydrated cake.
Measurement and reduce measurement errors.
Dewatering near the dewatering cake outlet of the belt press dewatering machine
Because the cake is flat, there is little variation in the measurement distance.
Measurement error can be further reduced. In addition, the dehydrated cake
Determine the average value of the water content in the width direction to determine the actual water content
can do.

[Brief description of the drawings]

FIG. 1 is a schematic view showing one embodiment in which the present invention is applied to a belt press type dehydrator.

FIG. 2 is a block diagram of an apparatus for measuring the moisture content of a dehydrated cake according to an embodiment.

FIG. 3 is a functional block diagram of the data processing device in the embodiment.

FIG. 4 is a graph showing the correlation between the absorbance of an infrared moisture meter and the measured moisture content of digested sludge, raw sludge, and mixed sludge.

FIG. 5 is a diagram illustrating an example of a luminance L value when a color difference of a dewatered cake made only of digested sludge is measured.

FIG. 6 is a diagram illustrating an example of a luminance L value when a color difference of a dehydrated cake is measured by changing a mixture ratio of digested sludge and raw sludge.

FIG. 7 is a front view of a mounting portion of the infrared moisture meter and the moving mechanism in the embodiment.

FIG. 8 is a plan view of the attachment portion.

FIG. 9 is a side view of the attachment portion.

FIG. 10 is a diagram illustrating an example of a distribution of dewatering properties in a width direction of a filter cloth of a belt press dehydrator.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Belt press type dehydrator, 2 ... Infrared moisture meter, 3 ... Moving mechanism, 4 ... Color difference meter, 5 ... Data processing device.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FIB30B 9/24 (72) Inventor Tomoyuki Hayashi 1-4-9 Kawagishi, Toda City, Saitama Prefecture Organo Research Institute (72) Inventor Toshinobu Imahama 1-4-9 Kawagishi, Toda City, Saitama Prefecture, Japan Organo Research Institute (72) Inventor Noriyuki Tsunakawa 4-12-6, Higashishinagawa, Shinagawa-ku, Tokyo Japan Tobacco Inc. (72) Inventor Masaki Shoji 2-20-46 Horifuna, Kita-ku, Tokyo JT Engineering Co., Ltd. (56) References JP-A-51-132887 (JP, A) JP-A-4-95856 (JP, A) JP-A-2-27227 (JP, A) JP-A-3-117750 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 21/00-21/61 G01N 27 / 06 G01N 33/24 C02F 11/12 ZAB B01D 33/048 B01D 33/58 B01D 33/80

Claims (2)

(57) [Claims] 1. A method for measuring the water content of a dewatered cake discharged from a belt press type dewatering machine, comprising measuring a plurality of types of dewatered cakes having different mixing ratios of digested sludge and raw sludge. The slope and intercept of the calibration curve of the infrared moisture meter
Stores the information of variation, using the belt press dewatering machine color difference meter which is arranged so as to face the dehydrated cake discharged from dehydration cake outlet dehydrated cake outlet near infrared moisture meter, the infrared Moisture meter of the filter cloth of the belt press type dehydrator
Reciprocating in the width direction, the infrared absorbance of the dehydrated cake
And the infrared moisture meter corresponding to the color information output by the color difference meter
The calibration curve of the infrared moisture meter is set based on the slope of the calibration curve , the intercept and the information of the variation, and the moisture content of the dehydrated cake is measured by the infrared moisture meter based on the set calibration curve of the infrared moisture meter. Measuring the moisture content of the dehydrated cake. 2. A color difference for measuring the color of the dewatered cake discharged from the dewatered cake outlet, which is disposed near the dewatered cake outlet of the belt press type dewatering machine so as to face the dewatered cake discharged from the dewatered cake outlet. and meter, when facing the dehydrated cake discharged from dehydration cake outlet near dehydrated cake outlet of the belt press dewatering machine DOO
Reciprocating in the width direction of the filter cloth of the belt press type dehydrator
Movably disposed, an infrared moisture meter for measuring the infrared absorbance of the dehydrated cake discharged from the dehydration cake outlet, the infrared moisture meter for dehydrated cake of a plurality of types having different mixing ratios of the digested sludge and raw sludge The slope and intercept of the calibration curve
Storage means for storing information of variation; inclination and intercept of a calibration curve of the infrared moisture meter stored in the storage means corresponding to color information output from the color difference meter
And a calibration curve setting means of the infrared moisture meter for setting a calibration curve of the infrared moisture meter based on the information of the variation .