Acetylene gas plants — designed, built and commissioned in India since 1947

Prices are indicative for a complete carbide-to-cylinder plant, ex-works, and move with the filling manifold size, the civil scope and the level of automation. The generation chemistry and the operating envelope are identical across all three: every carbide generator runs in the same low pressure band because that is set by the chemistry, not the capacity. What changes is throughput, the scale of the civil works, and how much redundancy you get.

Calcium carbide reacts with water to give acetylene and calcium hydroxide: CaC₂ + 2H₂O → C₂H₂ + Ca(OH)₂. In a KIGL carbide-to-water generator the carbide is screw-fed into a tank of water held below 70 °C, at 6 to 8 litres of water per kilogram of carbide, so the water absorbs the heat of reaction; the gas leaves at a fraction of a bar, is cooled, dried, purified to the IS 308 limits and compressed into acetone-charged cylinders. Good 25–50 mm carbide gives a minimum average of 300 litres of gas per kilogram. The full process, stage by stage, is in how acetylene is made from calcium carbide.

Calcium carbide and water react on contact, exothermically and irreversibly. There is no throttle. Everything that makes an acetylene plant safe and economic comes down to how precisely that reaction is metered, cooled and contained, which is why plants that look alike on a datasheet behave very differently in a shed in July.

KIGL has been building this equipment since 1947. Devendra Kumar Garg, KIGL's founder, has sat on the BIS committees that set the Indian standards for acetylene generators and cylinders since the 1970s, and was Convener of the dissolved acetylene cylinders and generators subcommittee when IS 15190 : 2002 was drafted — so KIGL plants are not merely certified against those standards: the family helped write them.

Eight stages, carbide in at one end and filled cylinders out at the other.

1. Carbide charging. Sized carbide, 4–50 mm, is fed through the hopper. Grading matters more than most operators expect: fines react too fast and spike both pressure and temperature, oversize reacts incompletely and wastes carbide.
2. Controlled generation. Carbide meets water in the generator. The reaction is held in the 0.2–0.92 kg/cm²g band, with a 1.05 kg/cm²g ceiling and a hard 70 °C limit. Cooling water is supplied at 1.5 × operating pressure.
3. Cooling and condensing. Gas leaves the generator hot and wet. The cooler-condenser drops it and knocks out the bulk of the moisture.
4. Low-pressure drying. Removes the water the condenser did not.
5. Purification. Strips phosphine and hydrogen sulphide, the impurities that determine whether the gas is fit for anything beyond rough cutting. The acetylene purification system has its own page.
6. Scrubbing. Final wet clean-up before compression.
7. Compression. An acetylene-rated compressor raises the gas to filling pressure. Acetylene compressors are not ordinary compressors: clearances, lubrication and materials are all specific to the gas.
8. High-pressure drying and filling. Final dry, then into the manifold for cylinder filling.

Lime slurry, the by-product, is discharged continuously and is the plant’s main effluent stream.

The last stage of the plant is where most buyers under-specify. Dissolved acetylene cannot be pumped into a cylinder the way oxygen can. The gas has to dissolve into the acetone held in the porous mass, and that takes time: a cylinder is filled slowly, over hours, and its temperature is watched throughout. The practical rule is to connect about eight times the plant's hourly capacity in cylinders to the manifold at once, so a 50 Nm³/h plant fills a bank of roughly 400 Nm³ of cylinder capacity in a shift.

A KIGL filling plant therefore includes the manifold sized to that rule, a back-pressure valve holding the manifold at 12 to 14 kg/cm²g, individual cylinder connections with flash back arrestors, cylinder weighing for the fill check, and a filling hall laid out to the Gas Cylinders Rules with a water deluge over the filling bay. KIGL fills its own cylinders at Guwahati through exactly this arrangement, which is why the manifold is designed by people who work alongside one.

Every approval routes to the Chief Controller of Explosives (CCE) at PESO, Nagpur. The order matters, because a customer cannot license storage without an approved generator:

1. Generator approval. The generator design is approved by the CCE under the Calcium Carbide Rules; KIGL's generators carry that approval and the BIS Standard Mark to IS 8471 (licence numbers on the approvals page).
2. Site layout. PESO's plant distances apply: 15 m to the boundary, 30 m to an oxygen plant, 90 m to an air-compressor intake. There is no 200 m public-building rule in India.
3. Carbide storage licence, for the carbide store, under the Calcium Carbide Rules.
4. Acetylene storage (Form F) licence under the Gas Cylinders Rules, 2016 — which requires the generator approval in step 1 to be in place.
5. Filling licence for the cylinder filling station, with the cylinder test records and the filling-station inspection that go with it.

KIGL prepares the drawings and the application set for each step with the plant. The sequence and the distances are also set out in the IS 8471 page.

A quotation is built against a stated filling duty — cylinders per shift, hours per day — and the configuration that meets it: generator size, purification train (chemical or PSA), compressor, number of HP driers, manifold banks and whether a drain-back manifold and cylinder sprays are included. Civil works, the PESO application set, operator training and the first year's consumables sit outside the plant price and are quoted separately so they can be compared. The largest recurring cost of owning the plant is carbide, which is why the yield per kilogram is logged every shift. Indicative plant price bands are published on the DA-25, DA-50 and DA-100 pages and in the industrial gas prices guide.

The failures that matter on an acetylene plant are rarely design defects. They are the design being dismantled during years of maintenance: a pressure switch removed because it tripped, a set point raised to make gas faster, a purifier bypassed because it flooded, a flame arrestor fitted where a flash back arrestor belongs, a high-pressure drier run without its drain, instruments drifting out of calibration, and corrosion on pressure-holding parts. None of these stops the plant producing gas, and none announces itself. Upstream of the plant, two raw-material failures do the rest: nitrogen for purging that is not as oxygen-free as its certificate claims, and metal fragments in the carbide that strike a spark in the screw feed.

KIGL plants ship with the interlocks above, an operating manual that states every set point, and a maintenance schedule built around keeping them. The operation and maintenance guide sets out the discipline.

A complete plant: generator, cooling and condensing, drying, purification, scrubbing, acetylene compressor, high-pressure drying and the cylinder filling manifold, plus erection supervision, commissioning, operator training and the operating manual.

KIGL ships and commissions across India, including all seven North-East states, West Bengal, Uttar Pradesh, Madhya Pradesh, Chhattisgarh, Bihar and Odisha. Equipment travels; unlike cylinder gas, distance is not a constraint.

Afterwards KIGL holds spares and offers annual maintenance support. Plants built decades ago are still running on parts KIGL still makes.