Ozone system can use air or oxygen as the gas source according to working conditions. Operations must ensure the inlet gas quality has a dew point lower than -60ºC and has no dust oil.
Air source is usually produced by on site air-treatment equipment. Oxygen can be by an on-site oxygen generator, liquid oxygen or pipeline oxygen.
The rated ozone concentration of Newland air-feed ozone generators are 35 mg/l and the max is 70 mg/l. the rated concentration of oxygen-feed generators are 150 mg/l, and the max ozone concentration can reach 270 mg/l. users can choose the appropriate gas source according to the requirement of ozone concentration. Ozone equipment and operation cost can be quite different because of the different gas sources. In addition, the noise problem when producing air and oxygen on site should be taken into consideration.
The main operational costs include the cost of the gas source and the electricity for the ozone generator. If cooling water cannot be reused, the water consumption also needs to be taken into consideration. The operation costs of various gas sources are quite different. The following table lists the operation cost comparison among liquid oxygen, air, on-site oxygen.
Outlet ozone concentration of oxygen-fed ozone systems can be adjusted greatly within the operating range (for example 0 – 270 mg/l). However, long term operating requirements should be taken into consideration for costs optimization when selecting system.
Taking oxygen-fed ozone system as an example, the operational cost includes the cost of oxygen and power consumption cost of ozone generator. Increasing ozone concentration may reduce oxygen consumption, but it would increase power consumption per kilogram of ozone.
The optimal operation concentration of Newland oxygen-feed ozone system is between 150 mg/l – 160 mg/l. The total operation cost is the lowest at this time. If the oxygen price is $0,18/m3 and the electric cost is $0,12/kwh, the oxygen cost and electric cost are about $2,28 per kilogram of ozone. The rated ozone concentration of the NLO ozone system is 150 mg/l, and the corresponding ozone output is rated output.
For each specific application, a reasonable ozone dosage can be determined through lab experiment or pilot test according to local conditions and requires treatment effect. If the ozone dosage is too low the required treatment will not be achieved. Too high an ozone dosage may not be economic, and may even produce toxic by-products, such as bromate. There is a great range of required ozone dosage depending on the application.
A large-scale ozone generator system consists of an oxygen or air source, ozone generator, power supply system, cooling water system, PLC control system, and an ozone dosing and ozone destruction system.
The discharge tube in the generator is the core technology and main component of the ozone system. It directly affects equipment efficiency and reliability
Newland NLO series ozone generator system adopts micro-gap dielectric-barrier discharge design. This reduces the system operating voltage to 4 kV; which is much lower than the glass tube dielectric material limit of around 50 kV. This minimizes any risk of short-circuit by dielectric breakdown, ensuring running efficiency and enhancing the continuous operational safety and reliability. In addition, high frequency discharge technology improves the working efficiency of the ozone generator which consequently reduces the generator footprint.
The Newland NLO ozone generator has a modular design wich makes the installation and maintenance convenient.
All the equipment is made of high quality ozone resistant materials (such as stainless steel SS316L, PTFE), which ensures reliability for long-term operation.
Under normal operating conditions, the discharge unit can be operated continuously for 10 years without maintenance.
Newland ozone system uses high frequency power supply technology, which is an improvement on medium frequency (<1 kHz) technology of traditional ozone generators, ensuring the reliability for long-term operating. With micro-gap discharge design, ozone generating efficiency can be improved, reducing the generator footprint.
High-frequency inverter power outputs sine wave, high voltage through a boost system, which connects to the generator discharge chamber through high voltage cable. With high frequency and high voltage, the discharge gap generates cold plasma, which discharges to generate ozone.
The ozone system can be controlled though a PLC human-machine interface (HMI) in the control cabinet or remotely monitored through networking between Ethernet and the plant Control Center. The main system operation parameters can be read from HMI or the Control Center.
In the manual mode, the ozone production rate can be entered according to operation requirements, and the system will automatically adjust operation parameters such as gas flow, gas pressure, and power to ensure the ozone output production and concentration meet the requirements.
In the automatic mode, the system automatically adjusts ozone production to meet the ozone dosage requirements taking into account the flow rate, ozone concentration in water or vent ozone concentration.
For oxygen-fed ozone systems, adding a small amount of nitrogen can improve the operation stability, reduce the corrosion of the electrode surface, and prolong operation lifetime of the discharge tubes.
Oil, dust, and moisture in the air not only reduce the generator´s operational efficiency and ozone concentration, but can also produce nitric acid on the electrode surface. Poor air quality can reduce the discharge efficiency and the overall performance of the ozone generator. Therefore, the nitrogen dosing system needs to have high quality air purification and drying equipment. Newland ozone systems use high quality air compressors, filters, and air dryers, to ensure the correct air quality in the ozone generator resulting in system reliability.
The efficiency of modern ozone generators has improved significantly compared with earlier products. However, part of input energy still turns into heat in the discharge gap. If the heat cannot be dissipated effectively, the temperature of the discharge gap can rise and exceed the design temperature. High temperature is not conducive to ozone generation as it accelerates the decomposition of ozone and reduces the ozone concentration and yield.
Small-scale ozone systems usually employ external circulation direct cooling. Large-scale ozone systems usually use internal circulation water cooling, which exchanges heat through a plate heat exchanger and external circulation cooling water. Internal circulation can guarantee the cooling water quality in the ozone generator, minimizing risk of deposit on the outer-wall of the discharge tube, and avoiding the reduction of heat exchange efficiency or tube leakage caused by corrosion.
When the temperature of cooling water exceeds the design temperature or if there is a water shortage, the system will send an alarm signal automatically.
Plate heat exchangers can be stainless steel SS304L or SS316L according to the water quality of external circulation cooling. Without special requirements, a SS304L exchanger would be sufficient.
Ozone can be transferred into water through ceramic, stainless steel or titanium plate micro-pore diffusers on the bottom of a contact tank. The tiny bubbles mix with water or air to ensure the required oxidation effect. More than 95% ozone will be absorbed and utilized in the contact tank, and the little remaining residual ozone will be decomposed to oxygen and exhausted into the atmosphere through the vent ozone destruction system.
The ozone destructor generally decomposes ozone through a high temperature heating method (380ºC) or heating-catalyzing method (40ºC). High-temperature heating method is more expensive but is more reliable. Heating-catalyzing method is less expensive, but consideration needs to be taken as to whether the vent gas contains components such as chlorine or sulfur which may destroy the catalyst. The heating-catalyzing destructor includes demister, heater, catalyst beds, fans and independent power control cabinet. The performance and lifetime of the destructor is determined by the quality of catalyst.
Newland ozone vent destructor uses high quality ozone destruct catalyst, with a normal service life of 5 and can often last up 10 years. The ozone concentration is less than 0,15 ppm after destruction meeting environmental emission standards. In some circumstances, the ozone off gas can be vented to the atmosphere without a destructor to save investment and operation costs.
Newland ozone systems use quality auxiliary components such as an ozone meter, flow meter, heat exchanger, valves, sensors, pumps, etc. to ensure the reliability of the system and maintain ozone production within the required operational parameters.
All auxiliary equipment is tested before leaving the factory to ensure operability and has serial numbers for ease of traceability, registration, installation and maintenance.
All of the pipelines and equipment which are in contact with ozone are made of stainless steel S316L. all interfaces in the pipeline are welded or connected by flange with PTFE seals to ensure the system operates reliably for long periods without leakage. The cooling water system usually uses HDPE, stainless steel SS304L or SS316L pipeline-connection.
Newland NLO series ozone generators use the most advanced discharge tube design and precise machining techniques to ensure outstanding performance and reliability.
Newland NLO series oxygen-fed ozone generators can produce ozone concentrations of 0-270 mg/l. the lowest operation cost can be obtained at the ozone concentration of 150 mg/l, with power consumption of 7,5kwh/kg ozone, 7 Nm³ gas consumption and 1,6 m³ cooling water.
Newland NLO series air-fed ozone generators can produce ozone concentrations of 0-70 mg/l. the lowest operation cost can be obtained at the ozone concentration of 35 mg/l, with power consumption of 16 kwh/kg ozone, 16 Nm³ gas consumption, and 4 m³ cooling water.
Newland NLO series ozone generators adopt modular design, which enables easy assembly work from small to large scale. The high capacity ozone production systems range from 0,1 kg/h to 130 kg/h, suitable for various applications.
Newland NLO series ozone generators use high-frequency discharge technology for a smaller size and thus reducing space requirements.
Newland NLO series ozone generators have excellent automatic performance because of its advanced control system. System data collection and automatic control can be performed through a plant control center.
Newland NLO series ozone generators use internationally recognized quality auxiliary components to ensure system reliability. The ozone specific auxiliary equipment and technologies, such as ozone vent destructor, ozone concentration monitor, ozone diffuser and advanced oxidation technology are of proven high quality providing rugged and reliable performance.
Newland has powerful scientific and technical strength and can offer multi-faceted technical solution, technical consultation and pilot experiments for customers.