JPS6059161B2 - ozone generator - Google Patents

Description

[Detailed Description of the Invention] This invention detects deterioration (increase) in the dew point of raw air,
This invention relates to an ozone generator that warns of a decrease in ozone production or shuts down the device.

Conventionally, there has been a device of this type as shown in FIG.

In the figure, 1 is a blower for supplying raw air, 2 is an air cooling device consisting of a primary cooler 3, a secondary cooler 4, and a refrigerator 5, 6 is an air drying device with a built-in heater for regenerating adsorbent,
7 is an ozone generator, 8 is a power supply device for applying high voltage to the ozone generator, 9 is a dew point meter for measuring the dew point of raw air, 10 is ozone generator 7, cooling water for the air cooling device 2 This is a cooling water pump that supplies Next, the operation of this conventional example will be explained.

The raw air is supplied by a blower 1, such as a Roots blower.
The air is taken in from outside air, compressed and pressurized, and sent to the air cooling device 2. In the air cooling system, the primary cooler 3
Cool air of about 5° C. is produced by water cooling by the secondary cooler 4, refrigerant gas produced by the refrigerator 5, or cold water cooling by the secondary cooler 4. This cold air is led to an air drying device 6, and supplied to an ozone generator 7 as highly dry air with an atmospheric pressure dew point of about -50° C. using a solid adsorbent. In the ozone generator 7, a silent discharge is generated between a high voltage electrode (glass electrode) and a ground electrode (metallic electrode), and ozone is generated from oxygen in the air in this discharge gap. The voltage is supplied by a power supply device 8 consisting of a control device such as a voltage regulator or a high frequency inverter, and a high voltage step-up transformer.In addition, cooling water is provided to suppress heat generation due to discharge in the ozone generator 7, and Cooling water to the primary cooler 3 and refrigerator 5 of the air cooling device 2 is supplied by a cooling water pump 10. Here, the dryness of the air supplied to the ozone generator 7 and the ozone generation efficiency are closely related. It is known that there is a When the temperature increases from -50°C to -30°C, the ozone generation efficiency decreases by about 15%.

Furthermore, when the dew point rises (deteriorates), the production of nitrogen oxides becomes noticeable, which causes nitric acid to be produced inside the ozone generator. This nitric acid reacts with other substances, causing dirt to adhere to the electrodes, which reduces the ozone generation efficiency and at the same time has an adverse effect such as corrosion on the materials that make up the equipment, impeding the operation of the ozone generator. Conventionally, there has been a device equipped with a dew point meter 9 between the air drying device 6 and the ozone generator 7 in order to prevent problems caused by a decrease in the dew point of the raw air.

Dew point meters that measure dew points above -50'C are known to detect changes in capacitance, but they are generally configured so that the dew point temperature and the meter's indication and output are linear. It was expensive because of its size. There is also deterioration of the sensor,
Calibration was required about once every six months to a year. For this reason, there are only a few ozone generators that are actually equipped with a dew point meter, and the reality is that the equipment is hardly managed in response to the dew point of the raw air. Conventional ozone generators are configured as described above, but those equipped with a dew point meter are rarely used in practice because dew point measurement requires more money than necessary and maintenance is troublesome. However, there was a drawback in that the dew point of the raw air was not controlled.

This invention was made to eliminate the above-mentioned drawbacks of the conventional method, and focused on the fact that there is a correlation between the adsorbent regeneration temperature in the adsorption tower of the air drying device and the dew point of the air at the outlet of the air cooling device. , by detecting the adsorbent regeneration temperature and associating it with a dew point alarm that has an alarm function, and by providing an in-clock element for ozone generator operation, an alarm will be issued when the dew point has risen above a predetermined level, and the operation will be activated. can be stopped,
- To provide a simple and inexpensive ozone generator that does not require a dew point meter.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows a heating regeneration type air drying section according to an embodiment of the present invention. The other parts are the same as the conventional example. Since they are the same, I will not explain them. That is, in FIG. 3, 6a and 6b are adsorption towers filled with adsorbent, 6c is an adsorption tower switching four-way valve, and 6
d is an air inlet, 6e is a dry air outlet, 6f and 6g are heaters installed in the adsorption tower, 6h and 61 have a function of detecting the adsorbent temperature and supplying an alarm signal to the outside at a set temperature. It is a temperature switch (temperature detector) with a 6j is a flow rate regulating valve that supplies a predetermined amount of dry air to the regeneration-side adsorption tower in order to utilize a portion of the dry air from the adsorption tower as regeneration air, and 6k is a regeneration air outlet.

In the above configuration, the air supplied from the air cooling device is 5°C.
The cold air before and after is guided to the adsorption tower through the air inlet 6d.

There are two adsorption towers, and while water adsorption is performed in one adsorption tower, the adsorbent that has already adsorbed water is regenerated in the other adsorption tower, and when the regeneration is completed, the four-way valve is switched and each tower performs the opposite process. The mechanism is such that this process is repeated alternately at an appropriately set time. For example, the air led to the adsorption tower 6a has moisture adsorbed by a solid adsorbent 6e such as activated alumina, and has a predetermined atmospheric pressure dew point (-50°C or less).
The resulting dry air is discharged from the dry air outlets 6 and e via the four-way valve 6c and guided to the ozone generator 7.

The dry air that has passed through the four-way valve 6c is partially branched as regeneration air, which is adjusted to a predetermined amount by a flow rate regulating valve 6j, and guided to the adsorption tower 6b. In the adsorption tower 6b, the adsorbent 6e is heated by a heater 6g installed in the tower, and the moisture adsorbed on the adsorbent 6e is turned into water vapor, which is then passed through the four-way valve 6 along with the regeneration gas.
c and is discharged to the outside of the system from the regeneration air outlet 6k. When the temperature of the adsorbent in the adsorption tower 6b reaches a predetermined value, the heating process is completed and the heater 6g is turned off, and then the adsorbent is cooled to near room temperature only by regeneration air, completing the entire regeneration process. After completion, the four-way valve is switched and the adsorption tower 6a enters the regeneration process.
The adsorption tower 6b enters the adsorption process. As mentioned above, the adsorption tower in which regeneration is performed has a heating process and a cooling process, and in particular, in this invention, the adsorbent temperature (or the temperature inside the tower) at the end of the heating process determines whether or not the moisture in the adsorbent has been completely removed. Focusing on the fact that it is an indicator of
is installed, and an alarm signal is sent to the outside when the adsorbent temperature (or tower internal temperature) at the end of the heating process falls below the optimum temperature value set by the temperature switch, thereby interlocking the operation of the ozone generator. This is an attempt to protect equipment, especially ozone generators.

Since the relationship between the dry air dew point and the adsorbent temperature (or tower internal temperature) at the end of the heating process is nonlinear, it is difficult to directly translate the adsorbent temperature value into the dry air dew point.
By determining the relationship between the adsorbent temperature at the end of the heating process and the dry air dew point during the tower's adsorption process in advance, the specified dew point (-50°C or less) can be ensured, and the dew point can be observed to increase over time. It is possible to determine the optimal adsorbent temperature at the end of the heating process, when the heating process is not possible, and by setting this as the alarm setting value, highly accurate dew point management is possible.

In this example, the switching cycle of adsorption and regeneration takes 8 hours, and the heating and cooling steps in the re-release process take 4 hours each, and when the adsorbent temperature rises to the set temperature value during the heating process, the thermostat turns on the heater. The power turns off (
The mechanism is actually designed to complete heating within 4 hours.

Therefore, an alarm function is configured by combining a timer and temperature switches 6h and 61 for detecting adsorbent temperature, which supplies an alarm signal to the outside when the adsorbent temperature does not reach a predetermined set value by the time the heating process is completed. By doing so, a control circuit is formed that warns of an abnormality and simultaneously stops ozone generation to protect the ozone generator 7. Since the temperature switch has a very simple structure, it can be used in a stable state at all times, and since it does not indicate the dew point, the alarm mechanism itself has a simple structure, which has the advantage of eliminating the need for maintenance.

In the above embodiment, a heater 6 is installed inside the adsorption towers 6a and 6b.
Although the heater is placed outside the adsorption tower and an independent regeneration circuit is provided, the same effects as in the above embodiment can be obtained.

Further, in the above embodiment, the alarm is driven by the signal from the temperature detector and the interlock means of the device is driven, but it is also possible to drive only one side, and the alarm can be activated by sound. Not only that, but it can also be something that can be conveyed visually.

As described above, according to the present invention, the rise in the dew point of the air is detected by detecting the temperature of the adsorbent in the adsorption tower that dries the air, so the device is inexpensive and requires no maintenance. It has become possible to equip ozone generators with dew point detection means.

Therefore, it is possible to prevent accidents in the ozone generator due to insufficient ozone production and nitric acid production, which is highly effective.

[Brief explanation of the drawing]

Figure 1 is a flow diagram showing the configuration of a conventional ozone generator.
FIG. 2 is a diagram showing the relationship between the dew point temperature of raw air and the ozone production efficiency, and FIG. 3 is a flow diagram of an air drying apparatus according to an embodiment of the present invention.

Claims (1)

[Claims] 1. An ozone generator that supplies raw air and generates ozone by silent discharge, an adsorption tower through which the raw air is passed before being supplied to the ozone generator, and an adsorption tower that is installed inside this adsorption tower to generate ozone in the raw air. It is equipped with an adsorbent that adsorbs moisture, a heater that regenerates the adsorbent by heating the adsorbent, and a temperature detector that detects the heating regeneration temperature of the adsorbent, and is driven by a signal from the temperature detector. The ozone generator is characterized by being provided with an alarm and/or a stop element for the ozone generator to warn of a decrease in the ozone generator due to an increase in the dew point of the raw air and/or to stop the ozone generator. Ozone generator.