Constructional featuresMulti-stage Diaphragm Compressors
Chemac diaphragm compressors are generally provided with all necessary fittings, as pressure gauges, oil overflow valves and compensation pump(s) for the hydraulic circulation, and completely fitted with tubes. In their standard design, they have a Vbelt drive with electric motor. All parts are mounted on a base frame made of steel, so a relief concrete foundation is not required. The new compressor generation is equipped with crank drives, which do no longer have any free dynamic forces and, thus, can be installed foundation-free. Upon request, the compressors can be equipped with a valve and instrument panel, which will be designed either for manual or for fully automatic control. Design of the machines is done in accordance to latest technical development, considering the harmonized European safety regulations (CE-marking) DIN EN 1012 part 1, DIN EN 292 und DIN EN 60204 part 1. For U.S. assembled/packaged units U.S. standards are used. Diaphragm
The metal diaphragms are fitted to be gas-tight (leakage rate normally approx. 10-4 mbar I/s, in special cases up to approx. 10-8 mbar I/s) and have an average life of approx. 4,000 hours, when working with clean uncontaminated gases. Cooling
Due to the large surface of the diaphragm head, a considerable part of the compression heat is lost to the atmosphere. Larger machines are equipped with an additional cooling system for the hydraulic oil. The gas-side cooling is done by interstage coolers and aftercoolers; if requested, 1-stage machines can also be supplied with or without aftercoolers, depending on the application. Oxygen Service
For compression of Oxygen, a noninflammable synthetic oil is used for the hydraulic system. Materials
Depending on the requirements, parts that come in contact with gas are mainly provided in carbon steel or stainless steel. Special designs in Silverin, Monel, Hastelloy, etc. can be supplied upon request. Principally, the diaphragms are made of CrNi-steel, quality 1.4310. For functional reasons, the suction and discharge valves are of chrome-steel. Depending an the operating conditions, the metal sealing rings are provided in copper, brass, or stainless steel. Diaphragm Failure Detection
For indicating a diaphragm failure, a system of multiple diaphragms is applied; 3 diaphragms are inserted together. The center diaphragm is slotted, thus allowing that pressure enters the collecting chamber in case a diaphragm failure happens on either gas side or oil side. If such pressure (either gas or oil) prevails in the collecting chamber, the pressure switch installed in the flange is actuated to activate an alarm or shut down the drive motor. Thus, the penetration of oil in the gas flow is prevented.
PDF Data Sheets: Hofer - Diaphragm Compressors