Introduction to Ozone Generation Techniques – Corona, UV and Electrochemistry

There are a number of vital things you need to recognize prior to you can acquire an ozone generator. Before going into details, however, it is essential to keep in mind that we are talking about corona discharge type ozone generators. These are the most important sort of commercial/industrial ozone generators. There are various other sorts of ozone generators, but non corona discharge systems are primarily for use in small range applications, creating commonly much less than half an extra pound per day or less than 10 grams per hour of ozone.

This post will certainly assess the crucial option elements and also just how it connects to various applications for ozone and the influence on the expense of an ozone generator.

The key factors consist of:

1. Output: This is how much ozone the maker makes, typically estimated in grams per hour or extra pounds per day.

2. Focus: Ozone can be produced at different focus varying from 1-12 weight percent. The focus of ozone has a result on a lot of applications and additionally influences equipment output.

3. Gas Feed: you must have a source of feed gas including oxygen, there are 3 options: dry air, oxygen focused from air or purchased oxygen (either as fluid oxygen (LOX) or pressed oxygen in cyndrical tubes).

4. Generator Cooling: Ozone generator create warmth that has to be gotten rid of, the alternatives for removing this warm are air cooling or water cooling.

Choosing the correct mix of attributes depends highly on the application. As an example, in water therapy applications higher concentrations of ozone are made use of while in air treatment applications lower concentrations can be chosen.

Ozone Generator Outcome

This is one of the most essential factor in picking an ozone generator. The quantity of ozone needed is based upon the application requirements. If the ozone is being made use of for elimination of organic contaminants from water, the quantity of ozone is symmetrical for natural in the water, the effectiveness of the ozone natural reaction and also the effectiveness of liquifying the ozone right into the water.

As a details instance, ozone is usually used to minimize chemical oxygen demand (COD) in water. COD is measured in ppm (milligrams per litre – mg/l). It normally takes 2 mg of ozone per mg of COD to eliminate the COD. So, if we had to treat 10,000 litres per hr of water consisting of 50 ppm of COD we would certainly require:

10,000 liters/hour X 50 mg/l COD x 2 mg Ozone/mg COD = 1,000,000 mg/hour

 

1,000,000 mg/hour = 1,000 g/hour = 1 kg/hour

So, we would require to dissolve 1 kg/h of ozone (or 52.8 extra pounds per day of ozone).

Less than 100% of the ozone injected in the water dissolves, so we require to recognize the ozone transfer performance. A well created venturi injection system can liquify a minimum of 90% of the ozone. For the case above, you would certainly require 1 kg/h รท 0.90 = 1.11 kg/h (58.7 pounds daily of ozone). This is the quantity of ozone we would certainly have to create at the targeted focus to dissolve the 1 kg/h of ozone into water.

Essential: A provided system will create less ozone as the concentration of ozone boosts. Ozone transfer efficiency, the rate at which ozone liquifies right into water enhances with boosting ozone focus. Both factors will certainly determine the last dimension of the equipment called for.

Identifying the quantity of ozone called for, except for the most basic applications, calls for lab or pilot research studies incorporated with a design evaluation to choose the proper balance in between ozone dose, focus and also generator size. Typically, an ozone generator firm will certainly not have the ability to supply this information. If they can assist, there will be an extra cost for conducting the researches.

Ozone Concentration.

As noted over, ozone concentration can influence both the performance of ozone in an offered application and the quantity of ozone that can be produced from an offered ozone generator. Basically, high concentration ozone costs a lot more, yet can do extra in particular applications. Business corona discharge systems produce anywhere from 1 weight percent ozone to 12 weight percent ozone. Gas treatment applications normally utilize the 1-3 percent variety while water therapy application generally utilize 5-10 percent.

An essential facet of ozone focus is in comparing various ozone generators. Producers make use of various bases for asserting the nominal result of an ozone generator. Usually, you have to read the fine print to see what focus they utilize to assert a provided manufacturing rate.

As an example:.

Outcome (g/h) Concentration (%) Cost.

Provider # 1 60 6 $5,500.

Distributor # 2 60 4 $3,800.

At similar focus the results would certainly look different:.

Provider # 2 60 6 $6,000.

( g/h = grams/hour).

So, to fairly compare machines you need to understand the quantity of ozone generated at a concentration of rate of interest in addition to the cost of the generator. This will certainly allow you to compare ozone generators “apples to apples”.

Ozone Generator Gas Feed.

Ozone generators can operate on various oxygen sources such completely dry air, focused oxygen or bought oxygen as a feed gas. First, a short discussion of feed gases. Initially, ozone generators primarily worked with air as the feed gas. Air consists of around 20% oxygen and also only the oxygen can be converted to ozone. Using air as the feed gas, the maximum economic focus of ozone that can be obtained has to do with 3 weight percent.

In addition, the air should be exceptionally dry due to the fact that moisture lowers ozone result and also will harm the ozone generator. To produce a practical concentration of ozone, the air needs to have a dryness as gauged by the humidity of concerning -100 levels Fahrenheit. This means that in a million parts of air there is only one part water. This degree of dry skin requires special dryers to remove the moisture. Chilled clothes dryers discovered on some compressors can just get to about a dew point of -40 degrees Fahrenheit.

Using a feed gas with oxygen focus more than 90% permits the ozone concentration to enhance to the 5-10 percent array. In addition, ozone generators generate greater results of ozone in terms of pounds daily or grams per hr using oxygen versus air.

Purchased oxygen typically is very completely dry because of the production process used. It can be bought as a pressed gas in cyndrical tubes or as a liquid. The volume that can be saved as a pressed gas is a lot smaller than in fluid form. So, unless the ozone generator is being only used for brief amounts of time, pressed gas is most likely not an excellent feed gas choice.

Fluid oxygen, occasionally described as LOX, can be provided in little containers or delivered in vehicle load quantities. It needs to be vaporized to the gas phase before make use of. It is one of the most economical form of oxygen if the oxygen production plant is not too away.

An additional alternative is to focus oxygen from air in a process called pressure swing absorption (PSA). In this process a product called a molecular screen absorbs both water as well as nitrogen from air leaving primarily oxygen in the gas stream. Oxygen focus of 90-95% are conveniently attained. The procedure is carried out in both little scale as well as huge commercial systems. Tiny applications consist of portable oxygen systems for people that require supplementary oxygen for breathing.

So, in recap the primary feed gases for ozone are completely dry air, PSA oxygen or fluid oxygen. Some ozone generators can operate on all 3 feed gas, yet this is not constantly the instance. Some ozone generator suppliers design their systems to run either on air or some form of greater concentration oxygen. It is essential to understand this in advance given that it may not be feasible to switch over when the device is purchased. The bottom line below is that if you desire greater concentration, you should make use of oxygen feed gas system with a generator developed to utilize this gas.

Ozone Generator Cooling.

All ozone generators produce heat as a result of the ozone manufacturing process. The generator needs to be kept cool considering that as the gas temperature enhances the ozone will certainly break down back right into oxygen making the process ineffective. Ozone generator suppliers provide their ozone result and also concentration information based upon a certain operating temperature, normally 68-72 levels Fahrenheit.

Every level above the specified temperature cause a decline of manufacturing. For instance, for every single level boost in temperature level the rate of ozone manufacturing lowers by 0.6% in some systems. So, if the device was supposed to operate at 72 degrees as well as it is actually run at 82 degrees the production would certainly be minimized by 6%. Some generators shut themselves down entirely at certain temperatures to avoid damage. So cooling down is a crucial problem for the generator.

There are two typical air conditioning techniques, air cooling with followers and also water cooling. Air air conditioning is less efficient as well as reduces the dimension of the ozone generator that can be constructed. In general, ozone generation of over 10 extra pound per day can not be conveniently performed with air cooled down ozone systems.

Water cooled down systems can be found in laboratory ozone generator several variations. Closed loop systems utilize a water chiller to cool the water and also cycle it continually via the ozone generator. Water generally enters the ozone generator at around 60 levels F and leaves at 70 levels F.

Indirect cooling loops making use of ground water or various other water sources are likewise made use of. Right here a warmth exchanger has one side linked to the ozone generator with a recycling loop as well as beyond a when via flow of water available at the site. Often the water temperature level is higher than maximum and a larger generator must be purchased to compensate for the loss of manufacturing.

The option of the kind of water air conditioning and also making use of a refrigerator is based on an engineering research to balance the expense of the boosted generator dimension with the cost of chilling the water.

Recap.

To sum up the bottom lines:.

1. Specify the application meticulously to establish the quantity and concentration of ozone called for. If you do not know the proper quantity of ozone required contract with a qualified lab or design firm to execute the required research studies.

2. Make sure to contrast ozone manufacturing of various ozone generators at the very same ozone focus to get a reasonable contrast of rate.

3. For applications needing above 5 percent ozone, oxygen will certainly be necessary for the feed gas. This will be typical for many water treatment applications.

4. For applications needing reduced concentrations of ozone, much less than 3 percent, completely dry air is most likely the most economical service. These would typically be applications for air therapy, such as smell control or control of air borne bacteria.

5. For applications of much less than 10 pounds each day (much less than 190 g/h) air cooled systems may be ideal, but above this degree water cooled down systems will likely be more cost-effective.