Elements

Description

The Desiccant Air Treatment Center is designed for long life and ease of maintenance. The ATC system is a pre-packaged unit incorporating all dryers, filters, regulators, monitors and by-pass valving required for the treatment of medical air per NFPA-99 recommendations. The design is such that any component may be used with any other and not affect system performance.

The ATC consists of two full-size desiccant air dryers, two inline pre-filters, two inline after-filters, two pressure regulators, a dew point monitor, a carbon monoxide monitor, a pressure alarm switch, an outlet pressure gauge and all necessary isolation valves. All components are packaged in a space-saving configuration, mounted to a welded steel frame capable of fitting through a standard 36" wide door The ATC requires only two piping connections (inlet and outlet) and one electrical connection. All interconnecting piping is copper or brass with brazed connections.

The twin tower desiccant dryers are mounted in parallel and are valved so that each dryer can be easily isolated from the system. The dryers are regenerative with full size pressure vessels and activated alumina desiccant. Each dryer maintains a constant -40°F pressure dew point. The purge controller continuously monitors the exact dewpoint and adjusts the amount of purge air required to completely regenerate the system, thus reducing the load on the air compressors. The purge air control valves are rated for 5 million cycles. The maximum working pressure if 150 psig @ 120 degrees F.

The duplexed coalescing dryer pre-filters are rated for 0.01 micron removal of solid particles and 99.999+% of oil aerosols, to protect the desiccant bed from contamination. The pre-filters are equipped with internal automatic float drain and a differential pressure gauge for filter change indication.

The duplexed particulate dryer after-filters are rated for 1.0 micron removal of solid particles, to prevent desiccant dust carryover into the medical air stream. After filters are equipped with a differential pressure gauge for filter change indication.

The air line regulators are capable of reducing inlet air pressure to an outlet range of
0-125 psig. Each regulator is self-relieving, diaphragm operated, with zinc body. The outlet pressure is controlled by a T-handle and the unit incorporates an outlet pressure gauge.

The system is equipped with monitors to display the pressure dew point as well as carbon monoxide levels in the medical air stream. The dew point monitor utilizes aluminum oxide to measure dew point through changes in the electrical resistance of the sensor element. Additionally the dew point monitor continuously monitors and controls the exact dewpoint and adjusts the amount of purge air required to completely regenerate the system, thus reducing the total run time of the compressed air system. The carbon monoxide monitor uses a sensor that analyzes the air and produces a small voltage proportional to the amount of carbon monoxide in the sample gas. Both monitors are equipped and audible and visual alarms and dry contacts for remote alarm connection along with a test/reset button.

The ATC is shipped with an alarm pressure switch for contractor installation down-stream of the system source valve. The pressure switch is capable of sending a signal to a remote alarm indicating abnormal system pressure. A pressure gauge is installed at the outlet of the system. A pressure relief valve, set at 75psi, is installed at the system outlet.
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