N2 Generator

NTGT series membrane nitrogen generator. Up to 300 Nm³/h at 97% purity, made from the ship’s own compressed air, so there are no cylinders to store or replace. ABS type approved.

On this page

• How it works›
• Specification›
• Monitoring and control›
• The unit›
• Features and options›

How it works

Nitrogen is separated from compressed air across a membrane rather than stored. Air from the ship’s compressor is cleaned and warmed, then passed through hollow fibres: oxygen diffuses out through the fibre wall quickly, nitrogen does not, and what carries on to the outlet is nitrogen at the purity the system is set to hold.

1. Filter — U, P and S grade	Air from the compressor enters the generator panel and passes the filters, which take out oil and solid particles. Separated oil and moisture are discharged automatically by a filter drain unit, and a differential pressure gauge shows when the elements are due for change
2. Heater	Air temperature decides the quality. At the right temperature the moisture and liquid oil evaporate and the nitrogen yield rises. A heat controller monitors the temperature and holds it steady
3. Membrane	Compressed air flows into hollow fibres. Oxygen, carbon dioxide and the other components diffuse out rapidly; nitrogen has a low diffusion rate and passes on. Capacity follows the flow rate, temperature and pressure the compressor delivers
4. Automatic control	The control panel watches the oxygen concentration and the nitrogen flow, and works an automatic control valve. Above 3.5% oxygen the operator gets an alarm; above 4% the system shuts down
5. Charge and discharge	Nitrogen is charged to the buffer tank up to 10 bar and recharges automatically when the tank falls below 5 bar, both adjustable. Nitrogen that does not meet the set quality goes out through the exhaust line rather than into the tank

Specification

Model	NTGT series, numbered by capacity — NTGT-160 is the 160 Nm³/h unit
Operating principle	Membrane separation
Membrane arrangement	Parallel
Location	Safe area, weather protected. Control section IP44
Capacity	Up to 300 Nm³/h
Nitrogen purity	97 vol%
Dew point	−65 °C at atmospheric pressure
Outlet pressure	10 barg at the generator outlet (process design)
Buffer tank start / stop	5 to 10 barg, adjustable
Outlet temperature	50 °C maximum
Filtration	Particle size 0.01 µm and oil removal 99.99%, both ISO 8573.1:2009 class 1
Heater supply	440 V / 60 Hz / 3 ph, 4 kW
Control panel supply	220 V / 60 Hz / 1 ph, 0.5 kW

Monitoring and control

Main screen	Nitrogen purity, air inlet pressure, nitrogen tank pressure and nitrogen flow rate
P&ID screen	The same readings against the plant diagram, with oxygen content, temperature and dew point
Gas detector screen	Sensor values with audible and visual alarm. Supplied as an option
Interface	PLC and human machine interface with a touch screen, buzzer, alarm lamp and emergency stop

The unit

Control section	PLC, human machine interface, buzzer, alarm lamp and emergency stop button. IP44
Membrane and process section	Membrane module, oxygen sensor, pressure transmitter, temperature sensor, dew point meter, air filter, heater, control valve and three-way valve
Connections	Compressor air inlet, specification in and out lines, vent out line and drain line

Features and options

• Parameters adjustable from the panel
• Remote control
• Serial communication to the ship’s systems — Modbus RTU over RS-485, as an option
• Gas detection monitoring, as an option
• Dual system with cross over, where a second train is wanted
• ABS type approval

Send the nitrogen demand in Nm³/h, the purity you need and the air the compressor can deliver, and we will size the unit and quote.