JP2000070970A - Controller for ozone contact reservoir - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the leakage of ozone and to reduce the load on an ozone contact reservoir by keeping the negative pressure in the ozone contact reservoir constant. SOLUTION: One of ozone generators 1 is operated in the normal quantity state of treating water. At this time, waste ozone is treated in a waste ozone treating device 13 by fully opening a motor-driven valve 11, and both two ozone contact reservoirs 4, 5 are regularly operated. In such a case, ozone is sent to the ozone contact reservoirs 4, 5 through an ozone header 3. The treating quantity to be sent to the ozone contact reservoirs 4, 5 is made difference in accordance with the pipeline length to vary the inner pressure of the ozone contact reservoirs 4, 5. This controller 19 decides the opening degree of the motor-driven valve or the number of revolutions of vent fans 14, 16 based on the ascending rate or the descending rate of the water level corresponding to the variation of the water level of the ozone contact reservoirs 4 5. The negative pressure of the ozone contact reservoir is controlled in constant by sending the signal to the operation device of the motor-driven valve or the vent fans 4, 16 thereby operating the motor-driven valve or the vent fans 14, 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an ozone contact pond that prevents ozone leakage and reduces the load on the ozone contact pond by maintaining a constant negative pressure in the ozone contact pond.

[0002]

2. Description of the Related Art Conventionally, the negative pressure in an ozone contact pond has fluctuated depending on the water level of the ozone contact pond. Released to the atmosphere.

[0003]

As described above, in the conventional method of discharging a constant amount of exhausted ozone air to the atmosphere by the exhaust fan, the possibility of ozone leakage may occur if the pressure in the ozone contact pond becomes positive due to fluctuations in the water level of the ozone contact pond. In addition, there is a problem that if the negative pressure in the ozone contact pond is too large, a load is imposed on the ozone contact pond.

[0004] Claim 1 of the present invention has been made to solve the above-mentioned problem, and an object of the present invention is to prevent ozone leakage and maintain load on the ozone contact pond by maintaining a constant negative pressure in the ozone contact pond. An object of the present invention is to provide a control device for an ozone contact pond that controls so as to reduce the amount of ozone.

[0005]

According to a first aspect of the present invention, there is provided an ozone contact pond control device, comprising: an ozone generator; and an ozone to which ozone generated by the ozone generator is supplied. A contact pond, an exhaust ozone treatment device to which exhaust ozone gas of the ozone contact pond is supplied via an electric valve provided at an outlet side of the ozone contact pond, and an exhaust fan provided at an outlet side of the exhaust ozone treatment device. A control device for inputting the water level of the ozone contact pond and controlling the negative pressure of the ozone contact pond to be constant, wherein the control device calculates a water level rising speed or a falling speed and The opening degree of the motor-operated valve or the rotation speed of the exhaust fan is determined based on the rising speed or the lowering speed, and a signal is sent to a driving device of the motor-operated valve or the exhaust fan, It is characterized in that constant control the negative pressure of the ozone contact basin by operating the valve operating or the exhaust fan.

According to the first aspect of the present invention, since the negative pressure in the ozone contact pond can be kept constant, it is possible to prevent ozone leakage and reduce the load on the ozone contact pond.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention (corresponding to claim 1). In the figure, reference numerals 1 and 2 denote ozone generators for generating ozone, and reference numeral 3 denotes an ozone header tube for supplying the generated ozone to an ozone contact pond. Reference numerals 4 and 5 denote ozone contact ponds for bringing treated water into contact with ozone, and the water levels of the ozone contact ponds 4 and 5 are measured by respective water level meters 6 and 7. Ozone contact pond 4,
The exhaust ozone gas outlet pipe 5 is provided with electric valves 8 and 9, respectively, and the exhaust ozone gas passes through an exhaust ozone header pipe 10 and electric valves 11 and 12 to exhaust ozone treatment devices 13 and 15 for treating the exhaust ozone gas, respectively. Supplied. The gases treated by the exhaust ozone gas treatment devices 13 and 15 are released to the atmosphere by exhaust fans 14 and 16.

The opening of each of the electric valves 8, 9, 11, 12 is adjusted by a valve driving device 17, and each of the exhaust fans 14, 16,
Are driven by the fan driving device 18. Control device 19
Detects the negative pressure of the ozone contact ponds 4 and 5, and detects each electric valve 8,
A function for determining the valve opening amounts of 9, 11, and 12 is provided.

Next, the operation of this embodiment will be described.
Here, for convenience of explanation, it is assumed that one of the ozone generators 1 is operated at a normal amount of treated water. At this time, the electric valve 11 is fully opened, and the exhaust ozone treatment is performed by the exhaust ozone treatment device 13. Ozone contact pond 4 and ozone contact pond 5 are 2
The pond will be used regularly. For example, when one ozone generator 1 is operating, ozone is sent to the ozone contact ponds 4 and 5 via the ozone header tube 3. The amount of treated water to the ozone contact pond 4 and the ozone contact pond 5 varies depending on the pipe length. Thereby, the internal pressures of the ozone contact ponds 4 and 5 fluctuate.

Now, let the bottom area of the ozone contact pond 4 be S
₁ [m ² ], the treated water volume increases, and the water level becomes H ₁ [m].
When it rises, it means that the volume of exhaust ozone gas of H ₁ × S ₁ = Q ₁ [m ³ ] has increased.

The amount of air that can be exhausted by the exhaust fan 14 is Q
Assuming that _H [m ³ ], when Q _H > normal air volume + Q ₁ , the pressure inside the ozone contact pond 4 remains negative. At this time,
The valve opening of the motor-operated valve 8 is slightly widened, and an operation of increasing the amount of ozone exhausted from the ozone contact pond 4 is performed. Further, the Q _H <normal airflow + Q _1, ozone contact basin 4 becomes a positive pressure, there is a possibility that the ozone leaks. At this time, an operation of increasing the valve opening of the electric valve 8 and increasing the amount of ozone exhausted from the ozone contact pond 4 is performed. Also, at this time, considering the rising speed of the water level, the fluctuation speed of the water level is not constant, and may rise slowly or sometimes rapidly.

Next, the procedure for determining the valve opening or the exhaust fan speed based on the fluctuation of the water level will be described with reference to the flowchart of FIG. The normal water level and H _0, measure the water level H _A at time T _A of the ozone contact basin 4 (step S
1) Input to the ozone contact pond negative pressure constant control device 19. The water level velocity L _A [m / h] of the ozone contact pond 4 is H _A −H ₀
/ T _A is calculated by -T _A-1 (step S2).

[0013] _{Next, L A [m / h]} -L A-1 [m / h]
By calculating the time T _A-1 -T from _A-2 time T _A -
The amount of change in the water level rising speed at TA _-1 is determined, and the current state of the motor-operated valve 8, the opening operation, the closing operation, or the current state of the exhaust fan speed, ascending, and descending are determined.

That is, (1) It is determined whether or not L _(A-1)-(A-2) -LA- _(A-1) = 0 (step S3), and L _{(A-1)- (A-2)} -L _{A- (A-1)} =
If it is 0, the current state of the motor-operated valve or the current state of the exhaust fan speed is maintained (step S4).

[0015] _{(2) L (A-1} ) - (A-2) -L A- when _(A-1) = not 0, it is determined whether an _{L A -L A-1 <0} ( In step S5), if L _A -L _A-1 <0, it is determined that the motor-operated valve is opened or the exhaust fan speed is increased (step S6).

[0016] _{(3) L (A-1} ) - (A-2) -L A- (A-1) = not 0, if it is determined that neither _{L A -L A-1 <0} , the electric valve closed Operation or exhaust fan speed drop (step S
7). The signal of the increase / decrease amount of the valve opening calculated as described above is sent to the valve driving device 17, and each of the electric valves 8, 9, 1
Adjust the valve opening of 1,12.

Further, the amount of treated water decreases, and the water level becomes H
_{When it} falls by ₂ [m], it means that the volume of exhausted ozone gas of H ₂ × S ₁ = Q ₂ m ³ has decreased.

Assuming that the air volume that can be exhausted by the exhaust fan is Q _H , if Q _H > normal air volume−Q ₂ , the pressure inside the ozone contact pond 4 will be further negative. At this time,
The operation of closing the valve opening of the electric valve 8 and reducing the amount of ozone exhausted from the ozone contact pond 4 is performed. Further, the Q _H <normal airflow -Q _2, ozone contact basin 4 becomes a positive pressure, there is a possibility that the ozone leaks. At this time, an operation of increasing the valve opening of the electric valve 8 and increasing the amount of ozone exhausted from the ozone contact pond 4 is performed.

Next, in the above state, the descending speed of the water level is considered. The fluctuation rate of the water level is not constant, and may gradually decrease, or may decrease rapidly. Normal water level H
_0, and when the water level H _B at time T _B of the ozone contact basin 4 is input to the ozone contact basin negative pressure constant control unit 19, the water level rate _{H B -H 0 / T B -T} B-1 = L B [ m / h].

Next, by calculating L _B -L _B-1 , the amount of change in the speed of the descent from the time T _B-1 -T _B-2 to the time T _B -T _B-1 is determined. The opening operation amount of the valve 8 is determined. The calculated increase / decrease amount of the valve opening of the motor-operated valve 8 is sent to the valve driving device 17 to adjust the valve opening of the motor-operated valve 8. The above operation is similarly performed for the ozone contact pond 5.

Further, another operation of this embodiment will be described. For convenience of explanation, it is assumed that one of the ozone generators 1 is operated at a normal amount of treated water, and at this time, the electric valve 11
Is fully opened, and the waste ozone treatment device 13 performs waste ozone treatment. Both the ozone contact pond 4 and the ozone contact pond 5 are normally used. For example, when one ozone generator 1 is operating, when ozone is sent to the ozone contact ponds 4 and 5 by the ozone header tube 3, the internal pressure of the ozone contact ponds 4 and 5 changes. .

Now, let the bottom area of the ozone contact pond 4 be S
₁ [m ² ], and the treated water volume increases and the water level becomes H ₁ [m].
When it rises, it means that the volume of exhaust ozone gas of H ₁ × S ₁ = Q ₁ [m ³ ] has increased.

The amount of air that can be exhausted by the exhaust fan 14 is Q
_H [m ³ ]. In Q _H> normal airflow + Q _1, ozone contact basin 4 remains negative pressure. At this time, the rotation speed of the exhaust fan 14 is slightly increased, and an operation of increasing the amount of exhausted ozone from the ozone contact pond 4 is performed. Further, the Q _H <normal airflow + Q _1, ozone contact basin 4 becomes a positive pressure, there is a possibility that the ozone leaks. At this time, the rotation speed of the exhaust fan 14 is further increased to increase the amount of ozone exhausted from the ozone contact pond 4.

Next, in the above state, the rising speed of the water level is considered. The rate of fluctuation of the water level is not constant, and may rise slowly or sometimes sharply. Normal water level H
_0, and when the water level H _A at time T _A of the ozone contact basin 4 is input to the ozone contact basin negative pressure constant control unit 19, the water level rate _{H A -H 0 / T A -T} A-1 = L A [ m / h].

Next, by calculating L _A -L _A-1 , the amount of change in the speed of the rise from time T _{A -1} -T _A-2 to time T _A -T _A-1 is determined, and the exhaust gas is exhausted. The rotation speed of the fan 14 is determined. The calculated number of revolutions of the exhaust fan is sent to the exhaust fan driving device 17 to adjust the air volume of the exhaust fan.

Further, the amount of treated water decreases, and the water level H ₂ [m]
Decreases, it means that the volume of the exhausted ozone gas of H ₂ × S ₁ = Q ₂ m ³ has decreased.

The exhaust fan 14 Datosuruto air flow rate Q _H can be discharged, in the Q _H> normal airflow -Q _2, the ozone ground battery 4 becomes more negative. At this time,
An operation of reducing the rotation speed of the exhaust fan 14 and reducing the amount of exhausted ozone from the ozone ground pond 4 is performed. Further, the Q _H <normal airflow -Q _2, ozone ground pond 4 becomes a positive pressure, there is a possibility that the ozone leaks. At this time, an operation of increasing the rotation speed of the exhaust fan 14 and increasing the amount of ozone exhausted from the ozone contact pond 4 is performed.

Further, the descending speed of the water level is considered. The fluctuation rate of the water level is not constant, and may gradually decrease, or may decrease rapidly. Normal water level is H ₀ ,
When the water level H _B at time T _B of the ozone contact basin 4 is input to the ozone contact basin negative pressure constant control unit 19, the water level rate _{H B -H 0 / T B -T} B-1 = L B [m / h ].

Next, by calculating L _B -L _B-1 , the amount of change in the speed of descent from time T _{B -1} -T _B-2 to time T _B -T _B-1 is determined, and exhaust gas is exhausted. The rotation speed of the fan 14 is determined. The calculated number of revolutions of the exhaust fan is sent to the exhaust fan driving device 17 to adjust the air volume of the exhaust fan. The above operation is similarly performed for the ozone contact pond 5.

[0030]

As described above, the present invention (Claim 1)
According to (correspondence), by maintaining the inside of the ozone contact pond at a constant negative pressure, ozone leakage can be prevented and the burden of the ozone contact pond due to water level fluctuation can be suppressed.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a flowchart showing a procedure for determining a valve opening or an exhaust fan speed by the ozone contact pond negative pressure constant control device of FIG. 1;

[Explanation of symbols]

1, 2, ozone generating device, 3, ozone header tube, 4,
5 ... Ozone contact pond, 6,7 ... Water level gauge, 8,9 ... Electric valve,
10: exhaust ozone header tube, 11, 12: electric valve, 1
3, 15 ... exhaust ozone treatment device, 14, 16 ... exhaust fan, 17 ... valve drive device, 18 ... fan drive device, 19 ...
Ozone contact pond negative pressure constant control device.

Claims (1)

[Claims] 1. An ozone generator, an ozone contact pond to which ozone generated by the ozone generator is supplied, and ozone gas discharged from the ozone contact pond via an electric valve provided at an outlet side of the ozone contact pond. The apparatus includes an exhaust ozone treatment device to be supplied, an exhaust fan provided on an outlet side of the exhaust ozone treatment device, and a control device that inputs a water level of the ozone contact pond and controls the negative pressure of the ozone contact pond constant. The control device determines the opening of the motor-operated valve or the number of revolutions of the exhaust fan based on the rising or lowering speed of the water level and the rising or lowering speed based on the fluctuation of the water level of the ozone contact pond. Sending the signal to the drive unit of the electric valve or the exhaust fan, and operating the electric valve or the exhaust fan to control the negative pressure of the ozone contact pond constant. Characteristic ozone contact pond control device.