Method for regulating a compressor installation with a dryer and compressor installation used therewith

A compressor installation comprising at least one compressor element (6) driven by an electric motor (9) and a the pressure conduit (11) including at least one cooler (17), at least one water separator (18) and a dryer (2) of the type comprising a pressure vessel (24) with a drying zone (3) and a regeneration zone (4), a rotor (25) rotating in this pressure vessel (24), which rotor is (35) filled with a regenerable drying agent, and an electric motor (33) for continuously rotating this rotor (25), such that the drying agent successively is moved through the drying zone (3) and the regeneration zone (4), wherein a branch (15) extends from the portion of the pressure conduit (11) which is situated between the (5) compressor element (6) and the cooler (17) towards the inlet of said regeneration zone (4), and a return conduit (21) extends from the outlet of this regeneration zone (4) over a cooler (22) and a second water separator (23) back to the pressure conduit (11);

• wherein the motor (9) driving the compressor element (6), as well as the motor (33) driving the rotor (25) is a motor with adjustable speed, the motor (9) driving the compressor element (6) being coupled to a regulation device (13) which regulates the speed of this motor (9) as a function of the consumption, whereas the motor (33) driving the rotor (25) of the dryer (2) also being coupled to a regulation device (13,38) which regulates the speed of the motor (9) as a function of at least one parameter of the compressed gas which is fed through the drying zone (3) or the regeneration zone (4) of the dryer (2);
• wherein the motor (9) driving the compressor element (6) and the motor (33) driving the rotor (25) of the dryer (2) are coupled to one and the same regulating device (13) which regulates the speed of both motors (9,33) as a function of the consumption.