Taking nitrogen onsite

Image credit: Atlas Copco Compressors

Nitrogen generators can be used onsite in order to save a company money and time. Manufacturers’ Monthly explains.

Compressed air is considered the fourth utility being used in many industries after water, gas and electricity, according to Atlas Copco Compressors. The company has nitrogen generator solutions that can help manufacturers produce nitrogen on-site.

Salena Estate Wines, based in South Australia’s Riverland district, invested in an Atlas Copco nitrogen generator in 2012. The winery’s operations manager, Claude Sarti, said once he had shown Bob Franchitto, the managing director of the winery, the potential cost savings of investing in an Atlas Copco nitrogen generator, it was an easy decision for him to make.

“Once he saw the figures he did not hesitate.”

Before having the nitrogen generator, the winery used the G-sized Nitrogen cylinders, which Sarti said made life very difficult and often dangerous for the workers.

“We had to wheel each cylinder on a trolley to the bottling line, dragging it over hoses and other obstacles. It was very difficult to man-handle them into place. And then the problem was they would only last an hour and a half on the bottling line, when we were in full production,” he said.

Sarti also mentioned it was important to be aware when the cylinder was going to run out, as the machine doesn’t operate unless there is a certain amount of pressure in the cylinder.

“Often the bottling line would just stop until someone went to change the bottle. On top of that, on a couple of occasions, someone had forgotten to re order the nitrogen gas bottles for the week, creating a significant amount of costly downtime.

“While the gas was quite economical to buy, when you include the delivery charges and the cylinder rental charges, it starts getting expensive, especially when you have to buy in 30-to-40 cylinders in any given period, depending on the time of the year,” he said.

Saving time and money

For Salena Estate Wines, the investment in a nitrogen generator helped save the company money and employees time, whereas previously the company was making a loss.

“If we had to stop the bottling line for just a half an hour, to change gas bottles or whatever, and we had six people on the bottling line that day, that’s three man hours lost that we had to pay for.

“If that happens on a regular basis, those costs soon add up, let alone the loss of production, which sometimes had to continue on to the next day because we haven’t finished the run,” he said.
The nitrogen is used on the winery’s bottling line for gas blanket cover and for flushing the bottling line.

“The system pre-evacuates the bottle with a jet of nitrogen to eliminate the oxygen, and the same on the exit of the filler, so that we have the nitrogen protecting the wine, making it last a little bit longer.

“We also use the nitrogen to empty our filters when we need to change product. Basically we use nitrogen to blow all the previous wine out of the system; the hoses, the filter cartridges, and the filler,” said Sarti.

He said the nitrogen is also used in the winery’s cellar operations, replacing the labour intensive dry ice system. “Carrying the dry ice in buckets up the stairs to the top of the 60-to-70-foot high tanks was not only a manual handling issue, but a very hard task.
“When all the tanks get hooked up properly to the nitrogen plant, all that will be eliminated. So rather than having two people working all day on a Friday, hauling buckets of dry ice up all those stairs, the nitrogen plant will eliminate all those costs and safety risks,” he said.

A robust, reliable solution

Atlas Copco Compressors product manager for oil-free ZH centrifugal turbo and high pressure air and gas compressors, Sonik Barot, said Atlas Copco nitrogen generators are extremely robust in design.

“We offer a fully integrated complete scope-of-supply package and the life of the equipment is more than 20 years,” he said. Having a robust systems on site as well as access to services provided by Atlas Copco Compressors allows companies to think less about breakdowns and more about productivity.

The company offers both PSA NGP/NGP+ and Membrane type NGM/NGM+ nitrogen generators with a flow rate from 1 Nm³/hour, up to 3,000 Nm³/hour. Oxygen, CO2, water vapour and other gases are adsorbed, and generate a continuous flow of nitrogen and a guaranteed nitrogen purity between 95 per cent to 99.9 per cent (10ppm Oxygen).

“The result is virtually pure nitrogen at the outlet of the generator,” said Barot. “The NGP/NGP+ series is a very cost-efficient source of nitrogen used in various industries such as food and beverage, minerals and metal product manufacturing, metal processing, and electronics.”

NGM/NGM+ Membrane type nitrogen generators work on the “permeation” principle – using proprietary membrane separation technology. The membrane fibres separate compressed air into component gases bypassing inexpensive compressed air through semipermeable membranes consisting of bundles of individual hollow fibres, and generate a continuous flow of nitrogen. Barot explained that Atlas Copco’s membrane nitrogen generators are flexible enough to adapt to customer specific applications in various industries like type filling, inserting, fire prevention and blanketing.

In the owner’s control

By having a nitrogen generator onsite, Atlas Copco Compressors helps its customers take control of their products. “It allows customers to generate their own nitrogen gas on-site, at the pressure, purity and flow they required, all for a fraction of the cost of conventional bottled or bulk nitrogen supplies,” said Barot.

“Further, Atlas Copco’s variable speed drive compressors allow automatic adjustment of flow and pressure to match the demands of the nitrogen generator unit and it dramatically increases customers’ productivity and lowers their energy consumption,” he said.

Barot explained that the energy savings for the nitrogen generator, when combined with an Atlas Copco compressor, offers up to 50 per cent energy savings. “It gives customers freedom from fluctuating nitrogen and delivery costs – allowing them to establish more accurate operational costs.”

He also highlighted that having a nitrogen generator onsite eliminates limitations that companies may otherwise encounter. “The physical properties of the industrial gases limit the distances over which products can be economically transported. Having static installation gives customers a continuous source of nitrogen at the required purity and pressure, with price stability,” said Barot.

“With 24/7 availability to pure nitrogen gas, this also means there is no production downtime.”

He also said that having a nitrogen generator on site reduces energy use and lowers a facility’s carbon footprint. “Consider the absence of diesel fuel and associated carbon emissions from truck delivery of nitrogen. Additionally, there is also a reduced risk of employee injuries from storage tanks or exposure to delivered liquid nitrogen. It also eliminates truck deliveries and movement on-site including bottled banks movements,” said Barot.

Improved Return on Investment (ROI)

The NGP/NGP+ PSA type nitrogen generators work on the pressure swing absorption technology principle, which Barot explained helps ROI.

“The Atlas Copco PSA type NGP+ nitrogen generator has the highest quality carbon molecules sieves and it has the highest process benefits. Due to that, it uses very little compressed air to generate the nitrogen. It requires compressors that are one or two sizes smaller than their competition,” said Barot.

“Therefore, it offers less capital investment right at the front and ongoing energy savings. NGP+ has the ultimate energy saver purge control algorithm, which senses if the nitrogen demand is less than NGP+. It will adjust the cycle time and reduce feed air consumption,” he said.

Barot also explained that the generators are tried and tested in-house to ensure customers are getting longevity and efficiency from their equipment. “All the components needed to generate on-site nitrogen are built to Atlas Copco Compressors’ quality and energy efficiency standards and tested for optimal performance and reliability.”