JPH04370753A - Method and device for monitoring deterioration of ozone decomposition catalyst - Google Patents

Abstract

PURPOSE:To obtain a monitoring method and device which can properly judge deterioration and life of an ozone decomposition catalyst at an inexpensive facility cost. CONSTITUTION:This device is provided with temperature sensors 7 and 8 which are provided at entrance and exit sides, an operator 11 which obtains an increase temperature difference (Tb-Ta) of a delivered ozone according to a catalyst reaction from an output signal of each temperature sensor, an alarm setting equipment 5, a timer 12 for setting judgment time, and an alarm 6 for an ozone decomposition catalyst 3 which is loaded into an ozone decomposition device 2. It is judged that the ozone decomposition catalyst deteriorated under conditions where an increase temperature difference value which is obtained by the operator 11 when the ozone decomposition device 2 operates does not exceed a temperature difference setting value which is determined by the alarm setting equipment 5 within a setting time which is determined by the timer 12. Then, an alarm equipment 6 is operated and an exchange timing of the ozone decomposition catalyst is reported to an outside.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for monitoring deterioration of an ozone decomposition catalyst for an exhaust ozone decomposition device attached to a water ozone treatment facility.

0002

BACKGROUND OF THE INVENTION For example, as an advanced treatment for water and sewage, ozone treatment equipment has become popular in recent years, which uses ozone to purify water by removing harmful substances and COD, sterilization, decolorization, and deodorization. In this water treatment process, ozone generated by an ozonizer is diffused into raw water introduced into a treatment tank for ozone treatment, and most of the supplied ozone is consumed by contact reaction with the raw water. On the other hand, surplus ozone that cannot be consumed is harmful to the human body if the concentration is high, so normally surplus ozone is not released directly into the atmosphere, but is accelerated through an exhaust ozone decomposition device to reduce the ozone concentration to 0.1 ppm.
After reducing the amount to the following level, it is released into the atmosphere.

On the other hand, as the exhaust ozone decomposition device,
Although methods are known in which exhaust ozone is adsorbed using activated carbon or the like, more recently, methods have been adopted in which ozone decomposition catalysts are used to efficiently decompose exhaust ozone. The composition of the ozone decomposition catalyst differs depending on the manufacturer, but generally a transition metal catalyst is used, which is mainly composed of manganese oxide and mixed with copper oxide.

By the way, the catalytic ability of the ozone decomposition catalyst gradually decreases with long-term use, so maintenance management is required to monitor the deterioration state of the catalyst and replace the catalyst with a new one when it reaches the end of its life. To solve this problem, in the past, an ozone concentration meter was used to monitor the deterioration of the catalyst, and when the ozone concentration measured at the outlet side of the ozone decomposition catalyst exceeded a preset concentration value, an alarm was issued and the ozone decomposition catalyst was replaced. Currently, we are dealing with deterioration monitoring methods that notify the outside of the problem.

FIG. 2 shows the configuration of the deterioration monitoring device for the ozone decomposition catalyst described above. In the figure, 1 is an ozone exhaust duct pulled out from the ozone treatment tank, 2 is an ozone decomposition device installed in the middle of the exhaust duct 1, and 3 is an ozone decomposition catalyst loaded inside the ozone decomposition device 2. Also,
The deterioration monitoring device for the ozone decomposition catalyst 3 is the ozone decomposition device 2.
It consists of an ozone concentration meter 4, an alarm setting device 5, an alarm device 6, etc. connected to the outlet side of the alarm. With this configuration, the ozone concentration of exhaust ozone on the outlet side of the ozone decomposition catalyst 3 is monitored by the ozone concentration meter 4, and the measured value is sent to the alarm setting device 5.
When the ozone concentration exceeds the set value set in , an alarm 6 is activated to notify the outside that the catalyst is deteriorating.

[0006]

[Problems to be Solved by the Invention] By the way, the ozone concentration meter used in the above-mentioned conventional device is very expensive, and in small and medium-sized water treatment facilities, the cost required to install an ozone concentration meter is about 3 times the cost of an ozone decomposition device. Therefore, there is a demand for a low-cost monitoring method and device capable of accurately determining the deterioration state and life of an ozone decomposition catalyst in place of an ozone concentration meter.

The present invention has been made in consideration of the above points, and its purpose is to provide a deterioration monitoring method that can accurately determine the deterioration and life of an ozone decomposition catalyst at a much lower cost than conventional ozone concentration meters. and equipment.

[0008]

[Means for Solving the Problems] In order to solve the above problems, in the catalyst deterioration determination method of the present invention, the temperature rise of the gas due to the catalytic reaction is determined based on the gas temperature measured at the inlet and outlet sides of the ozone decomposition catalyst. The difference is calculated, and the value of the temperature rise difference is compared with a predetermined temperature difference set value to determine the deterioration state of the ozone decomposition catalyst.

In order to more accurately determine the deterioration of the catalyst, it is also possible to determine whether the difference in temperature rise of the gas to be treated before and after passing through the ozone decomposition catalyst determined as described above exceeds the set temperature difference within a set time. There is a method of determining that the ozone decomposition catalyst has deteriorated under conditions that do not exceed

On the other hand, the deterioration monitoring device of the present invention used to carry out the deterioration monitoring method described above includes temperature sensors arranged on the inlet side and outlet side of the ozone decomposition catalyst, and detects the temperature before and after passing through the catalyst from the output signals of each temperature sensor. A calculator that calculates the gas temperature difference, an alarm setter for setting the temperature difference, a timer for setting the judgment time, and a calculator that calculates the temperature difference set value for the gas to be treated within the set time. It shall consist of an alarm that issues a warning of catalyst deterioration under conditions that do not exceed the conditions.

[0011]

[Operation] Since the above-mentioned ozone decomposition catalyst generates heat in the catalytic reaction, if the catalyst is functioning normally, the gas temperature of the exhaust ozone that has passed through the catalyst will be higher than the temperature before passing through the catalyst. On the other hand, when the ozone decomposition catalyst deteriorates, the heat generated by the catalytic reaction also decreases, so the increase in gas temperature decreases. Regarding this point, according to actual measurements by the inventors using Calolite (trade name) as an example of an ozone decomposition catalyst, when the catalyst is functioning normally, the temperature rise of the gas before and after passing through the catalyst is 40%. While the temperature rises to ~50℃deg, when the catalyst is deteriorated, the temperature rise is ~10~50℃.
It has been confirmed that the temperature will drop to 0℃deg.

[0012] Therefore, based on the temperature of exhaust ozone detected by temperature sensors at the inlet and outlet sides of the ozone decomposition catalyst, the difference in temperature rise of the gas accompanying the catalytic reaction is calculated by a calculator, and the value of the difference in temperature rise is calculated. By comparing the temperature difference set value (for example, 10 degrees Celsius) set in advance with the alarm setting device,
It can be determined whether the ozone decomposition catalyst is in a deteriorated state. In addition, the above temperature rise difference value is determined by the set time (
For example, if the ozone decomposition catalyst does not exceed a predetermined temperature difference set value within 30 to 60 minutes (the time required for the ozone decomposition catalyst to function normally from the start of use), it will be determined that the catalyst has deteriorated and an alarm will be activated. This makes it possible to accurately determine the lifespan of the ozone decomposition catalyst without misjudgment due to time factors, and to notify the outside of the time to replace it.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a deterioration monitoring device for an ozone decomposition catalyst according to an embodiment of the present invention, and the same members corresponding to those in FIG. 2 are given the same reference numerals. In this embodiment, temperature sensors (resistance thermometers) 7 and 8 are installed on the inlet and outlet sides of the ozone decomposition device 2, and their detection signals are sent to converters (current-voltage converters) 9, 10, and is subjected to arithmetic processing by an arithmetic unit (subtractor) 11. Further, an alarm setting device (temperature difference setting device) 5, a judgment time setting timer (timer with a built-in time-limited contact) 12, and an alarm device 6 are connected to the subsequent stage of the arithmetic unit 11. The temperature difference set value in the alarm setting device 5 is set at 10 degrees Celsius, and the timer 12 is operated to repeat automatic reset with a set time of 60 minutes.

In the above configuration, when the ozone decomposition device 2 is in operation, the gas temperature of exhaust ozone is detected by the temperature sensors 7 and 8 at the inlet and outlet sides of the ozone decomposition catalyst 3, and the detected temperature Ta , Tb, the computing unit 11 computes the temperature rise difference (Tb-Ta) before and after passing through the catalyst. Here, if the ozone decomposition catalyst 3 is functioning normally, the concentration of exhaust ozone released into the atmosphere via the ozone decomposition device 2 will be a value of 0.1 ppm or less, and the concentration of gas The temperature rise difference (Tb-Ta) is timer 1
Before the judgment setting time set in step 2 has elapsed, the temperature reaches 40 to 50°C due to heat generation from the catalytic reaction, and the alarm setting device 5
Exceeds the temperature difference set value (10 degrees Celsius) determined by Under this condition, it is determined that the ozone decomposition catalyst is functioning normally, and the alarm 6 does not operate.

On the other hand, when the ozone decomposition catalyst 3 deteriorates due to long-term use and its catalytic ability decreases, the value of the temperature rise difference (Tb
-Ta) also decreased to 10~0℃deg, alarm setting device 5
It becomes lower than the temperature difference set value (10 degrees Celsius) determined in . This state lasts for a set time (
If it continues even after 60 minutes), it is determined that the ozone decomposition catalyst 3 has deteriorated, and an operation command is given to the alarm 5. This causes the alarm device 6 to issue an alarm to notify the outside of the time to replace the ozone decomposition catalyst.

[0016]

[Effects of the Invention] As described above, in the method for monitoring the deterioration of an ozone decomposition catalyst according to the present invention, the deterioration of the ozone decomposition catalyst can be monitored based on the gas temperature measured before and after the ozone decomposition catalyst without monitoring the exhaust ozone concentration after decomposition treatment. Calculate the difference in temperature rise of the gas, compare this calculated value with the temperature difference setting value to determine whether the catalyst is functioning normally, and add the judgment time condition to the catalyst. Deterioration and service life can be accurately monitored and determined. Moreover, since an inexpensive temperature sensor can be used in place of an expensive ozone concentration meter, the cost of the equipment can be reduced by more than half compared to conventional devices.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an ozone decomposition catalyst deterioration monitoring device according to an embodiment of the present invention.

[Figure 2] Configuration diagram of a conventional ozone decomposition catalyst deterioration monitoring device

[Explanation of symbols]

2 Ozone decomposition equipment 3 Ozone decomposition catalyst 5 Alarm setting device 6 Alarm device 7 Temperature sensor 8 Temperature sensor 11 Arithmetic unit 12 Timer

Claims (3)

[Claims] Claim 1: An ozone decomposition catalyst that is loaded into an exhaust ozone decomposition device to decompose exhaust ozone, and the difference in temperature rise of gas due to a catalytic reaction based on gas temperatures measured at the inlet and outlet sides of the ozone decomposition catalyst. 1. A method for monitoring deterioration of an ozone decomposition catalyst, the method comprising calculating the difference in temperature rise and comparing the value of the temperature difference with a predetermined temperature difference setting value to determine the deterioration state of the ozone decomposition catalyst. 2. In the deterioration monitoring method according to claim 1, the ozone decomposition catalyst deteriorates under the condition that the temperature difference value of the gas to be treated before and after passing through the ozone decomposition catalyst does not exceed the temperature difference set value within a set time. A method for monitoring deterioration of an ozone decomposition catalyst, characterized by determining that the deterioration of an ozone decomposition catalyst has occurred. 3. A device used to carry out the deterioration monitoring method according to claim 2, which comprises temperature sensors arranged on the inlet side and outlet side of the ozone decomposition catalyst, and the temperature sensor before and after passing through the catalyst based on the output signals of each temperature sensor. A calculator that calculates the gas temperature difference, an alarm setter for setting the temperature difference, a timer for setting the judgment time, and a calculator that calculates the temperature difference set value for the gas to be treated within the set time. 1. A catalyst deterioration monitoring device for an exhaust ozone decomposition device, comprising an alarm that issues a warning of catalyst deterioration under conditions that do not exceed.