Air cooling apparatus

Air cooling apparatus (ACA) belongs to surface heat exchangers and is designed to cool gases and liquids, condense vapour and vapour-liquid products in manufacturing processes of chemical, petrochemical, oil-refining, and oil and gas industries. The cooled technical product moves inside the bimetallic ribbed pipes, transferring heat through their walls, which are cooled with forced atmospheric air.

ACA are divided into horizontal, vertical and zigzag in design. To operate in low temperature regions, ACA are manufactured with a recirculation system (external and internal). Air flow is forced by large-diameter fan wheels (0.6-5.2 m), which are installed on multipolar low speed electric motors. Belt transmissions may be used in case of demands for noise reduction. Upon the customer’s request, ACA are equipped with an automatic control system to control motor speed, louver attachments, temperature regimes, vibration pressure, etc., with transmitting the data to the top-level controller.

ACA are manufactured according to GOST R 51364-99, TR 3612-134-00220302-07, and TR 3612-127-00220302-2007. Operating pressure of the cooled product in a heat exchange section is 665 Pa (from vacuum) to 6 MPa. Both collector and chamber 32MPa ACA are manufactured for main compressor stations and cooling of ammonia reactor synthesis gas.

Depending on the requirements, ACA heat exchange sections are made of carbonaceous, heat-resistant, and corrosion-resistant steels and brasses. The sections are equipped with supporting pipes up to 16 m long and 16-38 mm in diameter. The supporting pipes are ribbed by means of helical rolling of ribs on an aluminium pipe put on a smooth supporting pipe, with forming a bimetallic ribbed pipe, or by means of aluminium or steel tape winding. The coefficient determines the number of ribbing ribs per 1 running meter, depending on supporting pipe diameter and the number of ribbing ribs. The coefficient is from 7.8 to 22.

ACA are subdivided into exhaust and forced apparatus. Exhaust ACA, in which diffuser and fan wheel are set above the heat exchange section and air is exhausted through the heat exchange pipes due to exhaustion, are used in southern regions with high solar activity. The section is protected by the diffuser, and there is no sunbeam heating. ACA with an under fan wheel belong to forced ACA. Air delivered to the heat exchange section has an exterior temperature and is denser than that after going through the cooled section.