JP3580708B2 - Sludge sample molding method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a method for forming a sludge sample when a sludge sample is formed and dried or ashed to measure a water content and a loss on ignition.
[0002]
[Prior art]
The properties of sludge carried into sludge treatment plants such as sewage sludge wide-area treatment plants are likely to fluctuate and affect the stable operation of incineration and melting plants, so the theoretical amount of air required for combustion is calculated in advance and incinerated. In order to stabilize the melting, the water content of the sludge and the ignition loss are sequentially measured.
[0003]
In a sewage test method generally used for this type of measurement (a manual analysis method based on a test method determined by the Japan Sewerage Association), the water content is determined by weighing a certain amount of sewage sludge and measuring it at 105 to 110C. It is calculated by drying for 2 hours, allowing to cool, and then measuring the weight again. The loss on ignition is calculated by igniting the sludge after the moisture content measurement at 600 ± 25 ° C for 1 hour, and then measuring the weight after cooling. Is calculated by
[0004]
In the actual measurement, as shown in FIG. 4, a sludge sample 23 supplied from a sludge supply nozzle 21 to a sample dish 22 is mechanically pressed or spatulated in order to uniformly dry and ignite the sludge. It is molded flat and then heated by a heating lamp arranged above the sample.
[0005]
[Problems to be solved by the invention]
However, even when the sludge sample is formed flat as described above, the temperature rise only on the sludge surface is large and a temperature difference is generated between the inside and the inside, and drying and incineration are not uniform, which is a factor of measurement error. .
[0006]
An object of the present invention is to provide a sludge sample forming method for forming a sludge sample into a shape that can be uniformly dried and ashed.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the sludge sample forming method of the present invention is a method for forming a sludge sample, drying or incineration, and measuring a water content and a loss on ignition. The sample is flattened with compressed air, and a concave portion reaching the bottom surface of the sample dish is formed in the central region with the compressed air .
[0008]
According to the above configuration, when the sludge sample is heated from above as usual, the surface of the sludge sample is directly heated, and the exposed surface of the central region of the sample dish corresponding to the recess of the sludge sample is directly heated. The lower surface of the sludge sample is heated by the heat transfer effect from the exposed surface, and the sludge sample is uniformly and efficiently dried and ashed, partly due to an increase in the surface area due to the concave portions.
[0009]
The number of the concave portions may be one or plural, but it is preferable that the concave portions are uniformly distributed throughout the sludge sample.
As a forming means, a mechanical press, a spatula, compressed air, or the like can be used, but compressed air is preferred from the viewpoint of adhesion of the sludge sample.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The dewatered sludge moisture content / ignition loss automatic measuring device shown in FIG. 1 is attached to a sludge conveying path (not shown) to a sludge incineration and melting treatment plant, and includes a measuring device main body 1 and a control panel 2. It is composed of
[0011]
The control panel 2 includes a PLC (Programmable Logic Controller) 3 and a heating lamp controller 3a, and operates a continuous automatic measurement program to operate a sludge sample supply pump 4 (a fixed amount pump) for supplying sludge to the measuring apparatus body 1. In addition, the control of the hand 5 for transporting sludge in the measuring device main body 1 and the temperature control in which a heating temperature pattern is automatically set are performed.
[0012]
Hereinafter, the procedure for measuring the water content and the ignition loss will be described.
The sludge sample supply pump 4 is operated for a certain period of time, and a certain amount of dewatered sludge from a sludge reservoir (not shown) is collected in the sludge sample supply pipe 6, and the same amount of dewatered sludge is pumped to the sludge collection chamber 7. To the sample dish 8.
[0013]
After the dewatered sludge on the sample dish 8 is formed, it is conveyed to the heating and weighing chamber 9 by the hand 5, weighed by the electronic balance 10, and then heated by the halogen lamp 11 and the thermocouple 12 to the preset heating. It is dried and ashed on the basis of the temperature pattern, and weighed by the electronic balance 10 after each step. Then, the water content and the ignition loss are calculated from the measured values.
[0014]
Exhaust gas generated in each process is discharged out of the system through an exhaust gas treatment device 13, and the ignition residue whose weight has been measured is re-transported to the sludge collection chamber 7 by the hand 5 and collected in the waste chamber 14.
[0015]
The procedure of forming the dewatered sludge will be described in detail.
As shown in FIG. 2A, the dewatered sludge 15 deposited below the sludge supply nozzle 16 at the end of the sludge sample supply pipe 6 is placed below the compressor 17 as shown in FIG. It is conveyed and flattened by compressed air 19 which is supplied from the compressor 17 downward through an air supply nozzle 18 over a wide range. Thereafter, in the central region of the flattened dewatered sludge 15, a concave portion 15 a reaching the bottom surface of the sample dish 8 is formed by compressed air 19 supplied downward from the compressor 17 through the air supply nozzle 18 to a narrow area. .
[0016]
By being molded in this manner, when heated from above by the halogen lamp 11, the surface of the dewatered sludge 15 is directly heated, and the exposed surface of the central region of the sample dish 8 corresponding to the recess 15 a of the dewatered sludge 15. Is directly heated, and the lower surface of the dewatered sludge 15 is heated by the heat transfer effect from the exposed surface, so that the dewatered sludge 15 is uniformly and efficiently dried and ashed. Measurement time can also be reduced.
[0017]
Moreover, since sludge does not adhere to the molding means as in the conventional molding method using a mechanical press or a spatula, it is attached to the molding means, and when the sludge is dried next time, the sludge is measured. The inconvenience of mixing and measuring the water content and loss on ignition of sludge having properties different from those of actual sludge is avoided.
[0018]
However, the dewatered sludge 15 does not necessarily need to be flattened, and uniform and efficient drying and incineration can be achieved only by forming the concave portion 15a. In addition, although the sludge may be attached or mixed, the flattening and the formation of the concave portion 15a may be performed by a mechanical press or a spatula with priority given to uniform and efficient drying and incineration.
[0019]
As shown in FIG. 3, if the plurality of recesses 15a are uniformly distributed throughout the dewatered sludge 15, the heat transfer effect is enhanced.
[0020]
【The invention's effect】
As described above, according to the present invention, by forming a recess reaching the bottom of the sample dish in the central region of the sludge sample, the surface of the sludge sample can be directly heated, and the sample dish exposed surface corresponding to the recess can be heated. The lower surface of the sludge sample can be heated by the heat transfer effect of the heating, and the sludge sample can be uniformly and efficiently dried and ashed. As a result, the measurement accuracy of the water content and the loss on ignition can be improved, and the measurement time can be shortened, so that sludge incineration and stabilization of melting can be achieved.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a schematic overall configuration of an automatic measuring apparatus for measuring the moisture content of dehydrated sludge and the loss on ignition, in which a sludge sample forming method according to an embodiment of the present invention is performed.
FIG. 2 is an explanatory view showing a procedure of the sludge sample molding method.
FIG. 3 is an explanatory view showing another formed sludge by the sludge sample forming method.
FIG. 4 is an explanatory view showing formed sludge by a conventional sludge sample forming method.
[Explanation of symbols]
8 Sample dish 15 Dewatered sludge 15a Recess 16 Sludge supply nozzle 19 Compressed air

Claims (1)

When a sludge sample is formed and dried or incinerated to measure the water content and loss on ignition, a fixed amount of the sludge sample supplied to the sample dish is flattened with compressed air, and the sample dish is compressed with compressed air in the central area. Forming a recess reaching the bottom surface of the sludge sample.

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