We specialise in manufacturing and supply oxygen gas plant that consists of two parts.. The lower column and upper column. In between the lower and upper columns there is a condenser, which acts as a reflux for the lower column and as a re-boiler for the upper column. The liquid air at the bottom of lower column separates through the trays to give crude Oxygen at the bottom and approximately 90% pure Nitrogen at the top. Crude Oxygen termed as rich liquid is then expanded through an Expansion Valve from the lower column to the middle of the upper column. Crude Nitrogen termed as poor liquid is expanded through another Expansion Valve from the top of the lower column to the top of the upper column. Due to difference in the boiling points, the pure Nitrogen boils over and accumulates at the top of the upper column and Oxygen, which accumulates at the bottom of the upper column.


The compressor through a filter suck atmospheric & is compressed to the design pressure. The compressed air is then passed through inter-coolers, industrial refrigerator, moisture separators, and then to the molecular sieve Battery for removal of Carbon Dioxide, Hydrocarbons and Moisture from the process Air. This pure air is then allowed to pass through the 1st Heat Exchanger, where it is cooled by the out going nitrogen and oxygen. Part of this cooled air is passed through expansion engine and the other part through the 2nd Heat Exchanger. Both them help in further cooling down the air, which is finally released to the bottom of the column through an expansion valve. The Air becomes liquid at this stage.


Salient feature

• High standard of purity of gases.
• Low power consumption.
• Easy maintainence.

Oxygen are removed through separate paths in Heat Exchangers, for cooling the incoming air. Oxygen is compressed to a prescribed settled pressure by a liquid pump and is directly filled into cylinders. Nitrogen is however available at a pressure of approximately O.5kg/cm2 and the same can be compressed into cylinders with help of an independent high- pressure compressor.

Normally the Nitrogen available is of 98.5% purity only and is let out into the atmosphere as waste product. However, when Nitrogen is to be filled, into the cylinders for commercial use, the plant is controlled by a change in the valve setting to make the mixed Air chamber operative to achieve the required Nitrogen purity. (Facility of filling Nitrogen gas (PPM Grade) and withdrawal of liquid Nitrogen is also possible.)

• No bulky gasholder required.
• Automatic controls for feeding water, maintaining temperatures, pressures, and slurry drain are, fool proof, efficient and are of international standard.
• Excellent absorption of gas in cylinders.
• No gas loss and high yield.
• Very simple and safe to operate.
• Low power consumption.
• Low maintenance cost.
• Manufactured as per Designs and Drawings approved by The Chief Controllers of Explosives.
• Manufactured under ISI quality marking.

Nitrous Oxide is produced by heating Ammonium Nitrate to a temperature of approx. 250 deg.C. Ammonium Nitrate is decomposed in the process to give a mixture of Nitrous Oxide and super heated steam. Impurities include Ammonium Nitrate fumes, Nitrogen and other oxides of Nitrogen. The steam and impurities are removed by scrubbing with water, caustic soda and sulfuric acid. Nitrogen present in traces is removed by bleeding from the top of storage vessels, where Nitrous Oxide in liquid state is stored after compression.

Properties of Nitrous Oxide: Nitrous Oxide is a chemical compound of Nitrogen and Oxygen. Its chemical name is N2O. It is a colourless, non flammable, nontoxic gas with slightly sweetish taste and odour. Well-known method of distributing Nitrous Oxide is as compressed liquid in cylinders of approved design. It keeps combustion, therefore organic oils and greases of petrochemical nature be kept away from Nitrous Oxide gas.

Gases like Oxygen and Nitrogen are filled in seamless steel Cylinders at high pressure ranging from 150 to 200 bar. Such cylinders are also subjected to various weather conditions and handling during use at consumer's place as well as during transport, loading and unloading.

Essentially, the cylinders are made of a material that has a flexibility of expansion and contraction during pressurization. For various reasons this flexibility of expansion and contraction begins to deteriorate over a period of time. Similarly, on account of other conditions such as filling, handling, transportation and shop floor conditions, there are chances of weight reduction over a period of time. It may also develop certain other defects normally rendering a cylinder unsafe for use.

Globally such cylinders are required to be periodically tested for visual damages, weight loss and loss of elasticity. In view of the dimension of damage, which can be caused by a bad cylinder, being known, most people prefer to test these high-pressure cylinders periodically and is a mandatory requirement for safety.

We provide a complete set-up of equipment for conducting a dependable and assured Hydraulic test for such cylinders.

The Expansion Engine is vertical, single acting, reciprocating type. This produces the cold required for the plant. High- pressure air enters through inlet valve at the start of downward stroke of the piston. On further downward motion, the inlet valve closes and entrapped Air expands. During upward stroke, outlet valve remains open and inlet valve remains closed. Therefore, in downward stroke Air enters the cylinder and expands. In the upward stroke the expanded air is pushed outside. The electric Motor is used to start the machine. Thereafter the Engine is moved by the Air pressure itself and during which time, the Engine motor retains the speed by acting as a brake. Since work is done by Air in rotating the flywheel, it loses its heat content (enthalpy), thus the Air gets cooled. This cooling is more than that of an expansion in an Expansion Valve. An elementary factor for the function of an Expansion Engine is to use dry and carbon Dioxide free Air, as otherwise, ice and dry ice will form on valve seats, causing mal-function. The approx. temperature drop across Expansion Engine is 50 to 70°C, depending on inlet air pressure, temperature and inlet cam position.

The Expansion Engine consists of three major units.

• The drive unit
• The cylinder unit for Air expansion
• The Hydraulic system for operating the valves

The drive unit is similar to any reciprocating machine with usual parts. Such as, crank case, crankshaft, connecting rod, crosshead, etc. The Expansion Engine has an extended crankshaft enabling the accommodation of the cam box. The moving parts are lubricated through a hole in crankshaft. Oil scrapper rings are provided to prevent oil escape to cylinder unit.