| 摘要 |
The compressed air flow in an air drier is directed to either one of its two drying towers (1, 2) by means of a switch-over valve (26), whose switch-over function is performed with the air drier unloaded by means of an unloader valve arranged between the air drier and a compressor (48). The unloader valve (14) is caused to perform its unloading function not only at a predetermined pressure in an air tank (49) to which the air is fed but also - by an electronic control device (53) - after a predetermined time during periods of prolonged continuous air loading from the compressor through the air drier even if said pressure is not reached. |
