JP3473641B2 - Chemical injection control device for deodorant - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deodorant chemical injection control device for injecting a deodorant into a source of odor such as sludge, and more particularly to a device for controlling the injection of odor components. Measure the concentration, and based on the measurement result,
The present invention relates to a deodorant chemical injection control device for performing chemical injection control. 2. Description of the Related Art Conventionally, this kind of chemical injection control device has a structure shown in FIG.
As shown in the figure, a belt press dewatering machine 10 for performing sewage treatment
Some sludge deodorizers are used for sludge deodorizers that measure odorous gas containing hydrogen sulfide as a main component and control the injection of deodorants. In the chemical injection control device 11, the odor gas whose concentration is measured by a sensor (not shown) is not always uniformly dispersed in the air. In addition, the measured density fluctuates even when air near the measurement location moves due to the influence of an external environment such as wind. In general, the location of the odor is
Due to insufficient dispersion of the generated density components, there is a large variation in the measured density. However, when the odor is measured and the drug injection control is to be performed, a sensor is installed around the dehydrator 10 which is a source of the odor in order to detect the injection effect of the deodorant as soon as possible. It is desirable. [0003] Therefore, in the above-mentioned chemical dosing control device 11, a place near an odor component generation place and a place where odor variation is as small as possible (for example, the upper part of the coagulation reaction tank 14, the outlet of the gravity dewatering part of the belt press dewatering machine 10 and the filtrate) The outlet is searched for, the odor gas is sampled from the above location, and the concentration of the odor gas is measured by, for example, an odor sensor provided in the chemical injection control device 11. Then, the chemical injection control device 11 operates the chemical injection pump 15 based on the measured value to deodorize the sludge sent from the sludge storage tank 13 to the coagulation reaction tank 14 using the sludge supply pump 12. The injection amount of the deodorant from the agent storage tank 16 (hereinafter, referred to as “drug injection amount”) was controlled. [0004] However, in the above-mentioned chemical injection control device, the concentration of the odor gas generated from the sludge, the insufficient diffusion of the odor gas generated from the odor source, etc. There is a problem that it is not possible to distinguish the fluctuation due to the measurement by the measurement value output from the sensor. For this reason, even if the measurement location has been selected with great difficulty, if the measurement value fluctuates due to movement of people, environmental fluctuations, etc., the amount of medicine injected will fluctuate regardless of the cause, and deodorization will occur. There is a problem that the deodorizing suppression effect of the agent is not stable. In addition, when observing the change in the odor gas concentration, it was detected that the odor gas concentration caused a large change in a short time, but the central concentration of the odor gas concentration that changed in a long time did not change significantly. Was. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a medicine injection control device which is hardly affected by environmental fluctuations and can perform stable medicine injection control. I do. In order to achieve the above object, the present invention relates to a deodorant chemical injection control device for injecting a deodorant into an odor generation source, wherein the control unit generates the odor from the odor generation source. A sensor for measuring the concentration of the odor component to be performed, a concentration calculating unit for performing a moving average process on the measurement result from the sensor, and calculating an average value of the odor component concentration, and a odor component concentration from the concentration calculation unit. An output operation unit that calculates and outputs a required amount of the deodorant based on the average value, and a chemical injection unit that performs an injection process of the deodorant based on an output signal from the output operation unit. A deodorant chemical injection control device is provided. [0007] The concentration value of the odor component within a predetermined time interval input from the sensor is subjected to moving average processing, and the amount of the deodorant injected is calculated based on the obtained average concentration to deodorize. Injection treatment of the deodorant suppresses the response to the instantaneous change of the deodorant gas concentration, and can control the chemical injection amount for the central concentration of the odor gas concentration that fluctuates over a long time. The effect of the environmental fluctuation in the chemical injection control of the present invention can be reduced. An embodiment of a deodorant chemical injection control apparatus according to the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram of a sludge deodorizing device using the chemical injection control device according to the present invention, and FIG. 2 is a configuration diagram showing a specific configuration of the chemical injection control device shown in FIG. In the figure, sludge is stored in a sludge storage tank 21 and supplied to a coagulation reaction tank 24 via a pipe 23 by the operation of a mud feed pump 22, where a coagulant is added and coagulation treatment is performed. . The coagulated sludge is
It is supplied to the dehydrator 25, where it is dehydrated and carried out. An odor gas containing hydrogen sulfide (H2S) as a main component is generated from the sludge. The chemical injection control device 30 includes a sampling unit 31 connected to a sampling pipe 26 provided above the agglutination reaction tank 24, which is a source of the odor gas, and an arithmetic unit electrically connected to the sampling unit 31. 32 and the arithmetic unit 3
2 and a chemical injection unit 33 connected to a pipe 28 provided below the deodorant storage tank 27 and a pipe 29 provided above the coagulation reaction tank 24. . The sampling unit 31 includes a sampling mechanism 31a connected to the agglutination reaction tank 24 via a sampling tube 26, and an odor sensor 31b provided in the sampling tube 26. The sampling mechanism 31a has an intake pump (not shown),
The odor gas generated from the agglutination reaction tank 24 is sampled and sucked through the sampling pipe 26, and the odor sensor 31b measures the concentration of the odor gas, and outputs a measurement signal proportional to the odor gas concentration in the arithmetic unit. 32. The arithmetic unit 32 includes the odor sensor 31
An operation unit 32a for presetting a time width (hereinafter, referred to as “moving addition average time”) for taking in the measurement signal from “b”.
And a density calculation unit 32b connected to the odor sensor 31b and the operation unit 32a, and an output calculation unit 32c connected to the concentration calculation unit 32b. Operation unit 3
In 2a, the moving average time can be adjusted in accordance with the situation at the site where the sludge deodorizing device is installed, the odor variation due to the installation position of the sampling pipe 26, and the like. The concentration calculator 32b performs a moving averaging process of the odor gas concentration based on the moving averaging time provided from the operation unit 32a, and outputs the calculation result to the output calculator 32c. That is, the density calculator 32b
For example, as shown in FIG. 3, when the measurement values S0 to S9 are output in time series from the odor sensor 31b, the total Sn of the measurement values input at the specific moving average time T is input. Average value divided by the number of data 6 Is calculated. The output calculation unit 32c performs calculation processing based on the average value obtained by performing the moving averaging processing,
For example, a proportional operation is performed to calculate a required medicine injection amount, and a control signal proportional to the medicine injection amount is output to the medicine injection unit 33. That is, the relationship between the odor gas concentration X and the chemical injection amount Y can be expressed by, for example, a linear function of Y = aX + b as shown in FIG. Here, a is a proportional coefficient, and b is a chemical injection amount when the odor gas concentration is “0”. Therefore, the output calculation unit 32c calculates a medicine injection amount by performing a proportional calculation based on the linear function. The chemical dispensing unit 33 includes the output calculating unit 32
Injection pump controller 3 that takes in control signal from c
3 a, a drug injection pump 33 b connected to the deodorant storage tank 27 via a pipe 28, and connected to the coagulation reaction tank 24 via a pipe 29, and a display unit which is provided as an option and displays the drug injection amount 33c. The chemical injection pump controller 33a controls the operation of the chemical injection pump 33b based on the taken control signal, and controls the injection of the deodorant from the deodorant storage tank 27 into the sludge of the coagulation reaction tank 24. I have. In the above-described embodiment, for example, even when a high odor concentration is instantaneously generated at the odor generation source and the odor sensor 31b outputs a large measurement signal to the arithmetic unit 32, the measured value is determined by the concentration calculation. Since the values are dispersed into the values of the moving average time by the unit 32b, the density value (average value) output to the output calculation unit 32c does not immediately increase. Similarly, even when the odor concentration that occurs is low, the measured value is similarly distributed to the value of the moving average time by the concentration calculation unit 32b. The value will not decrease immediately. Thus, in this embodiment, the output operation unit 3
The chemical injection amount of the deodorant calculated in 2c is small with respect to the instantaneous change in the odor gas concentration and is changed with respect to the central concentration of the odor gas concentration that fluctuates over a long period of time. Based on the above dosing amount, it is possible to control the operation of the dosing pump to perform the deodorant injection process, reduce the influence of environmental fluctuations such as people and wind, and achieve stable dosing control. Become. However, if the moving averaging time T is set to be too long, for example, if the central concentration of the odor is lowered due to an excessive amount of chemical injection, there is an opportunity to measure a low concentration for a long time. In addition, the amount of chemical injection is insufficient, and conversely, the amount of generated odor gas is high for a long time. Therefore, these cases may be considered when setting the moving average time T. Required. When such a situation occurs, a method of temporarily changing the moving average time set by the operation unit 32a to a short time, or changing a sampling cycle in the measurement time interval, for example, is also conceivable. As described above, when the time width for taking in the measurement result from the sensor can be changed, the time width can be adjusted to an optimum time width in accordance with the environmental fluctuation. In this embodiment, the odor gas is sampled from the agglutination reaction tank, which is the place where the odor component is generated. However, the place where the odor component is generated is also the gravity dehydration of the dehydrator as shown in the conventional example. There are a part drop and a filtrate drop. Therefore, the chemical injection control device according to the present invention can control the chemical injection amount of the deodorant by sampling odor gas from a plurality of odor component generation locations. In this case, for example, the arithmetic unit performs a moving averaging process of the measured odor gas concentration for each odor component generation location, and deodorizes based on the highest concentration value among the calculation results. The injection amount of the agent may be calculated to perform the injection control, or the above calculation results may be averaged to obtain an average value of the odor component concentration, and the medicine of the deodorant may be determined based on the average value. The dosing control may be performed by calculating the dosing amount. Here, for example, an average H 2 S concentration of 5 ppm
The effect on the output when suddenly high concentration (10 ppm) gas is received during the measurement is that the moving averaging time T is 5 minutes and the sampling period (from time t0 to time t1 such as sampling at each measurement time interval). When the period of the period is 1 second, the total number of samples is 60 (times / minute) × 5 (minutes) = 300 (times), so the output fluctuation is (10 (ppm) −5 (ppm)) / 300 (times) = 0.0166 ... ≒ 0.017 (ppm). Therefore, in this embodiment, the output fluctuation is 0.0
It was recognized that there was almost no effect on the output of the chemical injection due to an increase of just under 2 ppm. As described above, the present invention relates to a deodorant chemical injection control device for injecting a deodorant into an odor source, wherein the concentration of the odor component generated from the odor source is determined. A sensor to be measured, a concentration calculating unit for performing a moving average process on the measurement result from the sensor to calculate an average value of the odor component concentration, and an erasing unit based on the average value of the odor component concentration from the calculating unit. An output calculation unit that calculates and outputs the required amount of the odorant, and a chemical injection unit that performs an injection process of the deodorant based on an output signal from the output calculation unit. This makes it possible to perform stable drug injection control that is not easily affected.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of a sludge deodorizing device using a chemical injection control device according to the present invention. FIG. 2 is a configuration diagram showing a specific configuration of the medicine injection control device shown in FIG. 1; FIG. 3 is a diagram for explaining a moving averaging process by an output calculation unit shown in FIG. 2; FIG. 4 is a diagram showing a relationship between an odor gas concentration and a chemical injection amount. FIG. 5 is a configuration diagram of a sludge deodorizing device using a conventional chemical injection control device. [Description of Signs] 23, 28, 29 Piping 24 Coagulation reaction tank 25 Dehydrator 26 Sampling tube 27 Deodorant storage tank 30 Chemical injection control device 31 Sampling unit 31a Sampling mechanism 31b Odor sensor 32 Operation unit 32b Concentration operation unit 32c Output Operation unit 33 Dosing unit 33a Dosing pump controller 33b Dosing pump

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B01D 21/00-21/34 C02F 1/00-11/20

Claims (1)

(57) [Claim 1] In a deodorant chemical injection control device for injecting a deodorant into an odor source, a sensor for measuring the concentration of an odor component generated from the odor source is provided. A concentration calculating unit that calculates and averages the odor component concentration by moving and averaging the measurement result from the sensor; and, based on the average value of the odor component concentration from the concentration calculating unit, An output calculation unit for calculating and outputting a required amount; and a chemical injection means for performing an injection process of the deodorant based on an output signal from the output calculation unit. Chemical injection control device.