Oxygen concentrators are also called oxygen generators. Medically, they are used as an alternative to tanks containing compressed oxygen and are used to provide oxygen therapy.
The oxygen concentrators basically consist of two cylinders, which are filled with a zeolite material. This material selectively absorbs only nitrogen from the air. In every cycle, air is made to flow through the cylinder, which contains nitrogen molecules at a pressure of 1.4 atmospheres, while the other cylinder vents off the captured nitrogen molecules.
A complete cycle takes about 20 seconds and a standard sized concentrator produces a continuous flow of oxygen at a rate of 5 liters per second with the concentration of oxygen between 50% and 95%. The entire process is known as the Pressure Swing Adsorption (PSA).
Some concentrators also use the Vacuum Swing Adsorption (VSA) process to produce oxygen. Here, a single low pressure blower is used, along with a valve that helps in reversing the flow of air through the blower, which in turn forces the regeneration phase to occur under a vacuum. This kind is generally used by the aquaculture industry.
Oxygen concentrator filters are also sold along with the concentrators to purify the oxygen as per the requirements. The three types of filters available are cabinet, inlet, and bacterial (outlet). The filters should be cleaned and changed on a periodic basis. The frequency of changing and cleaning the filter depends on the environment and the industry.
The two types of oxygen concentrators available are 'on demand' or 'continuous'. Some manufactures even rent out the concentrators for short term. This also helps you in evaluating the concentrator and its features, before actually placing an order to purchase. Let us look at some of the required features before purchasing Oxygen concentrators.
- It should be fully automatic and should work at all times, without manual intervention.
- If continuous oxygen is very vital to your industry, then you should opt for the ones that come with a battery backup, which will ensure that the supply is never disrupted.It should be reliable and require little or no maintenance.
- The cost of operation should be low.
- Look for the ones which are micro-processor controlled, as they are more efficient and easier to use.
- The process of installation should be simple and easy.
- The concentrator should be such that the advantages it offers to your industry should completely outweigh the advantages offered by any other source, such as liquid oxygen or a compressed tank.
- The concentrators should be fabricated in accordance with all the relevant codes, like ASME, CSA, and NEMA.
- It should be capable of producing oxygen that is 95% pure with a dew point of -100°F.
- It should ideally have a LCD display that can be used to analyze its performance.
- The control knob should be easily accessible.
- Some concentrators are available with a variable flow meter, while some are available with a preset flow that come with a hand operated rotary switch. Analyze both types and decide which one suits your requirements best.
- Lastly, the concentrators that you buy should be available with a minimum of 3 - 5 years of warranty.
- You should assess the flow rate at which you will require oxygen, as the cost of the concentrator increases with an increase in the flow rate.
- The zeolite sieve which actually removes the nitrogen from air to provide pure oxygen, should come with a lifetime warranty.
- The chassis used and the body itself, should be steel coated to increase its durability.
Gather all the information that you can, before you purchase an industrial oxygen concentrator. The cost is not too high, but if the device is faulty, it could be dangerous and will also adversely impact your business.