Low Pressure Cylinder Filling Oxygen Nitrogen Plants

Capacities: Plants are available in the range of 50 m3/hr-10,000 m3/hr Oxygen or nitrogen gas. Cylinder Filling: Oxygen Nitrogen Gas can be filled in the cylinders as per the cylinder filling chart given below

1. Compression Of Atmospheric Air By Air Compressor
Air is compressed at a very pressure of 5-7 bar (kg/cm2). Air can be compressed at such low pressure by trouble free rotary compressor (Screw / Centrifugal Type advanced technology is employed in lieu of old bulky piston compressor)

2. Pre Cooling System
The second stage of the process uses a low pressure refrigerant for pre-cooling the processed air to temperature around 12 deg C before it enters the purifier.

3. Purification Of Air By Purifier
The air enters a purifier consisting of twin Molecular Sieve driers, working alternatively. The molecular sieves remove the carbon dioxide & moisture from the processed air before the air enters air separation unit.

4. Cooling Of Air By Turbo (Expander)
The air has to be cooled to sub zero temperatures for liquefaction & the cryogenic refrigeration & the cooling is provided by highly efficient turbo expander, which cools the air to temperature almost below -165 to-170 deg C.

5. Separation Of Liquid Air Into Oxygen And Nitrogen By Air Separation Column
Oil free, moisture free and Carbon Dioxide free air enters into low pressure fin type Heat Exchanger where the air is cooled below sub zero temperatures by air expansion process in the turbo expander.

Air gets liquefied when it enters the air separation column & gets separated into oxygen & nitrogen by the process of rectification. Oxygen is available at the outlet of the ASU at a purity of 99.6%. Nitrogen is also available at the outlet as a second product at purity of 99.9% upto 3ppm simultaneously without loss of oxygen product.

6. Compression Of Oxygen And Filling Of Oxygen In Cylinders
The final product in the form compressed oxygen / nitrogen goes to the high pressure oxygen cylinders at 150 bar or upto higher as required.

Main Components of Low Pressure cylinder filling plants:

(I) Air Compressor: Screw/low pressure- type: or oil free piston or centrifugal types
We employ the most advanced compressor series available in the market. They have a unique combination, meeting customer requirements for low installation, operating and maintenance costs with high dependability and ease of use.

Screw type rotary compressors are one of the most advanced and trouble free.

Centrifugal Type: No other turbo type oil free compressor can match its efficiency and economy. This ensures a consistent and highly reliable source of air supply. Maintenance is extremely low.

The final product in the form compressed oxygen or nitrogen goes to the high pressure oxygen cylinders at 150 bar or upto higher as required.

(II) Pre - Cooling system:
The pre-cooling system is a highly efficient skid mounted equipment provided with the main purpose of cooling down the air to a temperature of 5 to 8 degrees Celsius and thus to discharge the condensed water. We are using highly reliable compressors of European origin.

(III) Purifier:
The purifying system is the secondary process unit which is responsible for the removal of moisture, carbon dioxide, hydrocarbons as well as rare gases that are considered to be impurities in the process cycle of air separation. The structure essentially consists of double layered molecular sieves from “Zeochem” (Switzerland) along with alumina which acts as an adsorbent.

The process purifier is vital to the entire process and is greatly responsible for the purity of the final product i.e. Oxygen and Nitrogen in the Air separation Column. It consists of 2 skid mounted molecular sieve regeneration batteries that work on shifts and switch alternatively either manually or through a PLC control (optional).

• Range: 40 tO 800 M3/hr.
• Purity oxygen: 99.6%. Nitrogen: 99.99% or 3PPM
• Operating Air Pressure: 0.6 TO 0.7Mpa

Basic Principle:

The air separation plant is a plant recovering oxygen and nitrogen from air simultaneously. It advance low pressure technology process using rotary screw compressor (or low oil free piston compressor)and turbo expander. The feed air entering the Molecular Sieve purification system employed to remove the moisture and Co2 from the process air. The air is liquefied by cryogenic cooling using latest plate and fin high efficiency heat exchangers and turbo expander. The liquid air separates into oxygen nitrogen and inert gases in the air separation column.

Main Components

1.Air Compressor:
Rotary air compressors screw type can be used for smaller size plants upto 500m3/hr & 1000m3/hr. Centrifugal compressor can be used for higher size plants.

2.Air pre cooling system:
Air separation plants adopts chilling system in all air pre-cooling systems.

3.Air purification system:
This system beds of molecular sieve are used in the air purification system, it remove the Co2 & moisture for the process air at low-pressure

4.Rectification Column:
The unit in cold box are all low pressure technology. This unit employs the latest state of the art plate and fin exchanger, condenser and sub-coolers. The column is supplied as a packed unit complete with all the control systems including digital flow-meters, temperature, pressure available with high purity upto 2-3 ppm nitrogen as a second product without loss in oxygen production.

5.Turbo-expander:
Turbo-expander is used for giving cooling to the air for the liquefaction process and braked by booster, so as to reduce the expanded air column,stabilize the upper columns working condition and reduce power consumption. The turbine expander have complete trouble free working and long life and reliability.

6.Computer Control:
All the plants can be configured for automatic operation through a pc this will use a out switching valves of German or Japanese and motorized cryogenic valves on cold box.

Technical Specifications :

Model (O2/N2)	DCPT- 40/ 50	DCPT- 60/ 80	DCPT- 80/ 100	DCPT- 100/ 150	DCPT- 120/ 150	DCPT- 130/ 160	DCPT- 150/ 200	DCPT- 170/ 200
Oxygen Capacity Nm3/hr	40	60	80	100	120	130	150	170
Oxygen Purity % O2	99.6	99.6	99.6	99.6	99.6	99.6	99.6	99.6
Nitrogen Capacity Nm3/hr	50	80	100	150	150	160	200	200
Nitrogen Purity	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM
No of O2 cylinders per day (150 BAR*)	160	240	320	400	480	520	600	680

Model (O2/N2)	DCPT- 200/ 220	DCPT- 220/ 220	DCPT- 300/ 300	DCPT- 350/ 350	DCPT- 400/ 400	DCPT- 500/ 500	DCPT- 600/ 600	DCPT- 800/ 800
Oxygen Capacity Nm3/hr	200	220	300	350	400	500	600	800
Oxygen Purity % O2	99.6	99.6	99.6	99.6	99.6	99.6	99.6	99.6
Nitrogen Capacity Nm3/hr	220	220	300	350	400	500	600	800
Nitrogen Purity	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM
No of O2 cylinders per day (150 BAR*)	800	880	1200	1400	1600	2000	2400	3200

• Range: 1,000 TO 10,000M3/hr.
• Purity oxygen-99.6%. Nitrogen-99.99% or 3PPM
• Operating Air Pressure- 0.6 TO 0.7Mpa

This air separation plant mainly includes:

• air filter system
• air compressor system
• air pre cooling system

• Range: 1,000 TO 10,000M3/hr.
• Purity oxygen-99.6% .Nitrogen-99.99% or 3PPM
• Operating Air Pressure- 0.6 TO 0.7Mpa

This air separation plant mainly includes:

• air filter system
• Molecular sieve purifying system
• rectifying column system, nitrogen & oxygen compress and storage system, instrument control system, electric control system. etc.

Air filter and compression
Air enters the self cleaning air suction filter, after being removed of dust and other mechanical contaminants in it, then enters main air compressor, after compression air then enters the after cooler.

Air cooling and purifying
Air is cooled in the Pre-Cooling System before enters mole sieve adsorber, air which enters the evaporator of the Pre-Cooling System is cooled by the refrigerant.

Mole sieve purifying system includes two mole sieve adsorber and Steam heater or Electric heater. The mole sieve adsorber adsorbs water, CO2 and some hydrocarbon in the air, one mole sieve adsorber is regeneration while another one is work.

Air rectification
Air from adsorber is divided two stream: one stream enter directly main heat exchange, then enter lower column after cooled, the second stream enter main heat exchanger to cool after compressed by booster end of the expander and cooled by after cooler, then enter upper column after expanded by the expander.

The content of nitrogen will increase through rising gas connect with the reflux. Needed reflux liquid nitrogen is from condensate evaporator in the top of lower column, oxygen will be evaporated and nitrogen will be condensed in here.

• Lower column production as following from the top down
• Pure liquid nitrogen
• Poor oxygen liquid air with 20%O2
• Rich oxygen liquid air with 36.5%O2

All production in the lower column after sub cooler enter upper column as its reflux. Production of upper column as following from the top down:

• Waster nitrogen at the top.
• Liquid oxygen at the bottom

Direction which all production of upper column go Waster nitrogen is reheated to design temperature out of the cold box by main heat exchanger and sub cooler after drawn from the top of upper column, one steam is regenerated by molecular sieve absorber, the other is taken in water cool column to cool water.


Purity: Oxygen gas of 99.6% purity can be produced and *pure nitrogen of 99.9% upto 3ppm is produced.
without any los of the oxygen production. **voltage and frequency as per the country of installation.

Main Performance of the plant:

A. Oxygen purity 99.6% at 150-160 Bar(2200PSIG) for Oxygen cylinder filling
B. High purity Nitrogen 99.99%(ppm optional) or cylinder filling.

Model (O2/N2)	DCPT- 1000 /1200/ 30	DCPT- 1500/ 1500	DCPT- 2000/ 2000	DCPT- 2500/ 2200/ 70	DCPT- 1500/ 1500/ 45	DCPT- 3600/ 3600/ 100	DCPT- 6000/ 6000/ 200	DCPT- 10000/ 18000/ 380
Oxygen Capacity Nm3/hr (TPD)	32	48	64	80	50	115	190	320
Oxygen Purity % O2	99.6	99.6	99.6	99.6	99.6	99.6	99.6	99.6
Nitrogen Capacity Nm3/hr (TPD)	33	42	56	60	42	100	170	500
Nitrogen Purity	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM	99.9%- 99.99% 3PPM
No of O2 cylinders per day (150 BAR*)	4000	N/A	N/A	N/A	N/A	N/A	N/A	N/A