Wherever condensate accumulates, this must also be drained to avoid it being picked up and drawn back into the air flow. In order to avoid the time consuming blow-down of separators and other condensate locations, which is, moreover, accompanied by a costly loss of compressed air, automatic condensate drainage systems have been developed. Electronic drainage systems represent the present state of the art. Drains must be attuned to the special needs of compressed air condensate, as the latter is a mixture of water, oil and dirt particles, causing far more difficult operating conditions than, e.g., a pure water condensate from steam plants. Condensate from compressed air systems must be graded: Oil lubricated compression systems generate a condensate mixture of oil and water as a by-product, its ph-value being in the neutral range. Oil free compressing systems, on the other hand, cause a condensate with a ph-value in the acid range. Drains do not always function reliably, for which reason the concept "automatic condensate drain" should be approached cautiously. Very viscous, highly contaminated oil/water mixtures are the cause of malfunctions, for which reasons regular checks form an essential element of maintenance. Draining by means of solenoid valves, which remove the condensate at time controlled intervals, offer an alternative. The appropriate setting of the opening time of the solenoid valves presents a problem. This takes place as a function of pressure, however, the pressure level in the system is not permanently constant. For this reason, the draining of the condensate is always accompanied by the loss of more or less compressed air. Electronic condensate drains have established themselves in the market. This system uses an integrated sensor to monitor the quantity of condensate in the collecting chamber and adapts the period of opening to the collected condensate quantity. Using this system, the loss of compressed air is reduced to a negligible minimum, or almost completely eliminated.
Photo 3.4.4.1
