JPH0435718A - Sludge deodorizing apparatus - Google Patents

Abstract

PURPOSE:To realize a stable deodorizing effect in any time by outputting a specified control signal for a specified period from an arithmetic part and then outputting the signal based on the signal inputted from a gas sensor after the lapse of the specified period. CONSTITUTION:There are provided a storage vessel 4 of deodorant, a gas sensor 6 detecting the concn. of the odor component generated from sludge, the arithmetic part 8 inputted with the detecting signal from the gas sensor 6, and the chemicals injection pump 5 which controls the amount of injection of deodorant sent from the vessel 4 to be supplied to the sludge according to the output signal sent from the arithmetic part 8. The arithmetic part 8 outputs a specified control signal for a specified period, and then, after the lapse of the specified period, outputs the signal based on the signal inputted from the signal sent from the gas sensor 6. As a result, the odor generated from the sludge is stable, surely and efficiently prevented with the automatic control.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a sludge deodorizing device, and particularly to a sludge deodorizing device that can provide a stable and stable deodorizing effect even when a high concentration of odor is generated from time to time. Regarding deodorizing equipment.

[Prior Art and Prior Art] In the sludge treatment process, deodorizing agents are injected to suppress the generation of foul-smelling gas containing H2S and the like as a component below working environment standards. Conventionally, the deodorant injection method has been a fixed-dose method in which the deodorant is added at a fixed ratio to the amount of sludge.

However, with this method, the amount of deodorant to be injected is set regardless of the state of odor generation, so the amount of deodorant used is unnecessarily large, which increases chemical costs. In some cases, it may not be possible to prevent the occurrence of bad odors due to lack of
There were administrative and economic problems.

Therefore, the present applicant has developed an automatic chemical injection control system that continuously measures the odor gas components in the process gas using a gas sensor, and automatically calculates and injects the chemical amount according to the measured gas concentration. We proposed a system and applied for a patent in 1986-2.
No. 72709 to No. 63-27'2712), excellent improvement effects could be obtained.

[Problems to be Solved by the Invention] However, in the above-mentioned feedback control system that measures the odor of the processing gas, calculates the amount of medicine to be dispensed, and performs the medicine injection, it is difficult to sufficiently prevent the occurrence of bad odors due to control delays. You may not get it.

That is, for example, when sludge dewatering treatment is restarted after a certain period of suspension, at the beginning of the process, the sludge that was left in the sludge storage tank without being treated in the previous treatment is sent to the dewatering process for a certain period of time. It's coming.

This sludge (hereinafter referred to as "initial sludge") has deteriorated during the idle period in which it was stored in the storage tank, that is, between the end of the previous treatment and the start of the current treatment. It generates odor gas containing odor components in high concentration.

At the beginning of restarting the process when such initial sludge is sent, due to the time delay in feedback control from measuring the generated odorous gas components to dosing the chemical, the amount of deodorizing agent required to prevent bad odors may be reduced. Therefore, it was not possible to prevent the occurrence of bad odors.

An object of the present invention is to provide a sludge deodorizing device equipped with an automatic deodorant injection control system that can solve the above-mentioned problems caused by time delays in feedback control and can always obtain a stable deodorizing effect. do.

[Means for Solving the Problems] The sludge deodorizing apparatus of the present invention includes a deodorizing agent storage tank, a gas sensor that detects the concentration of odor components generated from the sludge, and a calculation unit into which a detection signal from the gas sensor is input. and a chemical injection pump that controls the amount of deodorant to be supplied from the storage tank to the sludge based on a signal output from the calculation unit, wherein the calculation unit It is characterized by outputting a specific control signal and, after a period has elapsed, outputting a signal according to the signal input from the gas sensor.

[Operation] In the sludge deodorizing apparatus of the present invention, the following signal A or B is output from the calculation section.

A, a certain control signal B, a signal according to the signal input from the gas sensor, that is, the above A signal for a certain period of time, and then the above B signal
Output a signal.

Therefore, for example, by performing the following control,
It is possible to reliably prevent the occurrence of bad odors. That is, as the A signal, a chemical injection signal that can correspond to the maximum concentration of odor gas that can be generated from sludge is set and manually input, and the A signal is output for a certain period from the beginning of the dehydration process. The time required for almost all of the sludge to be sent to the dewatering process, or the new sludge being pumped into the sludge storage tank due to the start of the process, reduces the impact of the initial sludge on the odor generated during the dewatering process. Set the time required.

As a result, the period during which the dehydration process is resumed and the initial sludge that generates odorous gas containing high concentration of odorous components is sent to the dewatering process, or the period during which the initial sludge generates high concentration of odorous gas in the dehydration process, Regardless of the detection signal of the gas sensor, the arithmetic unit outputs, as the A signal, a chemical injection signal that can correspond to the maximum concentration of odor gas that can be generated from the sludge.

Therefore, a large amount of deodorizing agent is supplied by the chemical injection pump, and the time delay in feedback control that controls chemical injection based on the detection signal of the gas sensor is eliminated, and the high concentration odor gas in the initial sludge is eliminated. This will definitely prevent bad odors.

In addition, in the present invention, there is no particular restriction on the set values of the A signal and the period for outputting the A signal set in the calculation unit, and are appropriately determined depending on the type of sludge treatment process in which the sludge deodorization device is installed. . That is, for example, for a treatment process in which there is a possibility that sludge that generates high concentration odor gas is sent in other than when the process is restarted, the A signal instructs the chemical dosing pump to inject a preset large amount of chemical for that period. It is possible to output a medicine injection signal (hereinafter referred to as a "large volume medicine injection signal", and a signal instructing a small quantity medicine injection to be referred to as a "small volume medicine injection signal"). Conversely, if sludge that generates low-concentration odor gas is sometimes fed, a small amount chemical injection signal preset as the A signal may be output during that period. Also,
A (It is also possible to set both a large amount drug injection signal and a small amount drug injection signal as item g, and output each signal in a certain set period.

Furthermore, the period for outputting the large-volume drug injection signal or the small-volume drug injection signal is not limited to being set in time as a preset period; It can also be set based on the concentration range of the odor gas detected by the gas sensor, such as until the concentration falls below a certain level.

As described above, according to the device of the present invention, it is possible to prevent excess or deficiency of deodorant and to perform good chemical injection control.

[Examples] Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a system diagram showing an example in which a sludge deodorizing apparatus according to an embodiment of the present invention is applied to a sewage sludge dewatering process.

In Fig. 1, sludge is transferred from pipe 11 to sludge storage 4iIt.
and stored within the system. The sludge in the sludge storage tank 1 is sent to a dehydrator 3 through a pipe 12 equipped with a sludge pump 2, where it is dehydrated, and a dehydrated cake is discharged through a pipe 13. A pipe 14 is connected to the pipe 12 and includes a chemical injection pump 5 for dosing the deodorant in the deodorant tank 4 .

In this embodiment, the dehydrator 3 is the source of bad odor. A gas sensor 6 is installed near the dehydrator 3, and the detected value of the gas sensor 6 is inputted to a calculation section 8 via a signal processing section 7. Furthermore, a synchronization signal that informs the operating state of the dehydrator is input to the calculation unit 8. This synchronization signal is
For example, it is a signal that typically indicates the start or stop of operation of a dehydrator, and specifically, it is a signal that reports the operating state of a slurry pump or the operating state of a dehydrator. Note that the calculation unit 8 is configured by, for example, a microcomputer,
It is said to be capable of various types of arithmetic processing and time-series processing using an internal timer.

In the sludge deodorizing apparatus of this embodiment, when the dehydrator 3 in the dehydration process, which is the controlled object, starts operating and starts the dewatering process, a synchronization signal indicating the start of the process is input to the calculation unit 8. In response to this synchronization signal, the calculation unit 8 outputs a chemical injection signal to the chemical injection pump 5 and starts chemical injection control, but at this time, for a certain period from the start of processing (this period is a constant period as described above). It may be a period of time, or it may be a period until the detection value of the gas sensor 6 becomes a certain concentration or less.)
Regardless of the detection signal manually input from the gas sensor 6, a preset chemical injection signal (in this case, a large-volume chemical injection signal) is output to the chemical injection pump 5, and a large amount of deodorant is supplied.

Then, after the certain period has elapsed, based on the detection signal input from the gas sensor 6, a drug injection signal calculated from the detected value is output.

In this way, during the period when high concentration odor gas is generated due to initial sludge, feedback control is not used.
By injecting a large amount of deodorant based on a preset large-volume injection signal, it is possible to reliably prevent bad odors caused by initial sludge.

The example shown in FIG. 1 is one embodiment of the present invention, and the present invention is not limited to what is shown in the figure unless it exceeds the gist of the invention. , it goes without saying that other embodiments can be adopted.

[Effects of the Invention] As detailed above, according to the sludge deodorizing apparatus of the present invention, it is possible to always stably and reliably prevent odors generated from sludge through automatic control.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an embodiment of the sludge deodorizing apparatus of the present invention. 1...Sludge storage tank, 2...Sludge supply pump, 3.
... Dehydrator, 4... Deodorant tank, 5...
- Chemical injection pump, 6... Gas sensor 7... Signal processing unit, 8... Calculation unit. Agent Patent Attorney Tsuyoshi Shigeno

Claims (1)

[Claims] (1) A deodorizer storage tank, a gas sensor that detects the concentration of odor components generated from sludge, a calculation unit into which the detection signal from the gas sensor is input, and a A sludge deodorizing device comprising a chemical dosing pump that controls the amount of deodorizing agent to be fed from a storage tank to sludge, wherein the calculation section outputs a specific control signal for a certain period of time, and after the period elapses, A sludge deodorizing device characterized by outputting a signal according to a signal input from a gas sensor.