Rexarc ATX Series Acetylene Cylinder Filling Plants

Expandable acetylene cylinder filling plants from 50 to 250 m3 per hour

The Rexarc ATX Series is a family of calcium carbide acetylene cylinder filling plants sized from 50 to 250 m3 per hour. Rexarc states that the closed medium-pressure system offers up to 25 percent more efficiency than other systems because it prevents wasted acetylene and helps maximise carbide yield, and that a programmable logic controller monitors operating conditions. The plants are skid-mounted and arrive pre-piped.

The generator is built to ASME Section VIII and produces acetylene at less than 0.6 bar (8 psig); two hoppers are used alternately for an uninterrupted flow. Rexarc designs the plant to NFPA 51A, and the ATX can be expanded later with a few added components, because all parts are retrofittable.

Technical specifications

Monthly production figures are for one shift per day. Water demand can be reduced by about 85 percent by using recirculating systems, and electrical requirements for other local supplies can be arranged.

Process and safety design

The process skid has a cooler condenser, ammonia scrubber (over 99 percent ammonia removal), medium-pressure drier, purifier and purifier scrubber, and is sized for 56 m3 per hour (2000 CFH). The purifier removes ammonia, hydrogen, phosphorus and sulphur to give acetylene of 99.5 percent purity. A 3-stage compressor takes acetylene from 0.4 bar to 25 bar with the compressor and cooling coils submerged in water. Three ASME-coded high-pressure driers follow, then charging manifolds with flame arresters before and after each shut-off valve and stem reverse-flow check valves on the cylinder leads. Rexarc also offers an acetylene atmosphere monitoring system, an intrinsically safe digital scale and an acetone pump.

Choosing the size

Select the model from the monthly cylinder volume in the table, then check carbide, acetone, water, power and building area. The site planning guides for Models 18, 36, 54, 72 and 90 are published by Rexarc. Rexarc offers installation, operator training and safety inspection services, which should be considered with any plant purchase, and local regulatory requirements decide the free area around the plant.

How the Rexarc ATX Series acetylene plant works

Acetylene is made by adding calcium carbide to water in a generator. The gas then has to be cooled, scrubbed and dried before it can be compressed into cylinders that hold acetone. In the ATX Series, the generator produces gas at less than 0.6 bar, and two hoppers are used in turn so that the carbide feed does not stop. The gas then passes through the cooler condenser, the ammonia scrubber, the medium-pressure drier and the purifier. A three-stage compressor takes it from 0.4 bar up to 25 bar, and the filling manifold loads the cylinders.

Where the ATX Series is used

• Industrial gas companies that fill acetylene cylinders.
• Plants that supply welding and cutting shops.
• Sites that want to expand their capacity later.
• Regions where calcium carbide is the preferred source of acetylene.

Selection checklist for the ATX Series

• Model from Model 18 to Model 90, based on the monthly cylinder count.
• Hourly capacity from 56 kg to 280 kg of acetylene.
• Cylinder size, with the table based on 6 kg cylinders.
• Carbide size of 25 x 50 mm and a dust limit of 15 percent.
• Electrical supply of 380 V, 50 Hz, three phase.
• Water supply per minute, and the option of recirculation.
• Acetone and carbide stock needed for the plant.
• Building area from about 297 to 813 square metres.
• Local safety codes, since the plant is designed to NFPA 51A.

Installation, commissioning and maintenance notes

The plants are skid-mounted and arrive pre-piped, which shortens the site work. Prepare the building, the foundation, the water supply and the power before delivery. Acetylene is a hazardous gas, so the site must follow the safety codes for generator buildings, gas detection and fire protection. Start-up takes about one to three hours, depending on the size, and operators must be trained before running the plant.

Requesting a quotation for the Rexarc ATX Series

Send the daily or monthly cylinder target, the cylinder size, the power and the water available. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

Scale and expansion of the ATX Series

The maker states that the parts are retrofittable, so the plant can be expanded later with a few added components. This lets a company start with a smaller model and grow as demand rises.

Purity and cleaning of the gas

The purifier removes ammonia, hydrogen, phosphorus and sulphur, and the stated purity is 99.5 percent. The ammonia scrubber removes more than 99 percent of the ammonia.

Water use and recirculation

Water demand can be cut by about 85 percent with a recirculating system, which matters in dry regions.

Safety practice for acetylene filling plants

Acetylene must never be handled at high pressure without the proper equipment, because it can decompose. The plant uses ASME-coded vessels and water-cooled compression, and operators should follow the written procedures for start-up, shutdown and emergencies. Keep ignition sources away from the generator building, test the gas detectors regularly, and keep the fire protection equipment ready.

Carbide handling and storage for the ATX Series

Keep carbide in sealed drums in a dry store, because moisture releases gas. Use carbide of the stated size and keep the dust content within the limit so that the generator runs evenly.

Documents and quotation

The Rexarc acetylene cylinder filling systems brochure (English) is attached under Datasheets & Documents; it is a 2005 form, so confirm current specifications with the quotation. See related equipment in our Oxy-Fuel Cutting Equipment category.

For a quotation, send the target monthly production, cylinder sizes, site area and electrical supply.