Gas Generators

Common questions – information

What is EST?
EST means Energy Safety Technology and it is a patented solution By Parker Domnick Hunter to adapt the productivity of the Nitrogen gas generators to the actual flow demand. Parker Domnick Hunter is the only gas generators manufacturer who has this system to their generators. The system is calculating the saturation of each CMS column and can excess the cycle of the regeneration. The system is actually matches compressed air flow to the nitrogen outlet flow and purity, reducing compressed air use, and saving energy and money. Bellow you can find a table with the average energy savings depending on the flow-rate demand percentage of a nitrogen generating system.

Flow Demand (%) Predicted Average Energy Savings (%)
10 71.0
15 65.9
20 61.3
25 57
30 53.1
35 49.6
40 46.5
45 43.6
50 41.0
55 38.6
60 36.2
65 33.9
70 31.5
75 29.0
80 26.2
85 23.0
90 19.4
95 15.1
100 10.0

What is parker Alliance ?
Parker Alliance is an extended manufacturer’s warranty, designed to ensure that supplied equipment provides maximum lifetime efficiency and performance, whilst minimising costly down-time through routine maintenance and breakdown for the equipment owner. Parker Alliance warranty provides cover from the date of invoice to the customer and is totally free to the equipment owner. The customer has to service his machines according to the recommended service intervals using genuine spare parts using an authorized service provider.

What determines the generator efficiency?
The efficiency of a gas generator is depending on the air inlet pressure and the purity of the supplied gas.

What data are required for the correct sizing of a gas generation system?
For the correct sizing of a gas generation system are requiring the gas pressure and gas flow-rate demand, the gas purity (we can propose the gas purity depending on the application) and the working temperature. Moreover in case the customer has his own compressed air system we would like to know the maximum and minimum air working pressure, the compressed air availability and the installed air pretreatment.

Do I need a Nitrogen storage vessel?
Many applications only need nitrogen during a predetermined time of the day (e.g. working hours) or have periods which need a higher flow rate than the normal ‘baseline’ flow rate so it is important to establish when to offer a storage vessel in addition to the generator(s). It is usually cheaper to offer a generator with a vessel than a generator that produces the (high) quantity at peak consumption. Therefore it is advisable to concentrate on the total consumption of N2 per day and then calculate the size of the storage vessel needed to supply with the generator to allow the size of the nitrogen generator required to be kept to a minimum.

Does temperature affects the outlet gas flow-rate?
Yes. All the gas generation systems are calculating the maximum outlet flow-rate at a temperature of 20-25 oC. The manufacturers are giving a temperature correction factor table for the correct sizing of the system in any temperature conditions within the limits of the operation temperature of the system.

Where can I use Gas Generation systems?
There are many applications and market sectors where gas generation systems can be used depending on the gas production. Some of them are the following. Food and Beverage, Pharmaceuticals, Fire prevention systems, Laser cutting, Tire inflation, Gas furnace, Hospitals, Cutting and welding etc.

Will a nitrogen generator cause an ambient oxygen decrease or increase?
In a normally ventilated plant room or factory, the generator blow down exhaust gases, do not generally have an effect on the ambient oxygen level. This is because the exhaust gases are not 100% oxygen. At initial start of the exhaust cycle the oxygen level peaks at approx. 45%, the nitrogen purge then reduces the oxygen level in the exhaust for the remainder of the cycle.
The net effect is little or no change in the ambient oxygen level. Sometimes if there are nitrogen storage vessels and large or multiple buffer vessels, insurance companies or health
and safety inspectors may ask for the pressure relief valve outlet port to be piped to outside. It is then necessary to select a PRV with a threaded port to accommodate this.

Is nitrogen completely inert?
For almost all applications nitrogen can be considered inert and un-reactive. However there are certain instances where nitrogen can have an effect or very rarely react with other substances. Nitrogen can be absorbed by certain metals in heat treatment applications and cause hardening by process called “Nitriding”. Nitrogen also reacts with Lithium, Titanium and Neodymium Nitrogen should not be used for laser cutting Titanium. The only suitable gas is Argon.