A continuous semi-dense phase conveying system comprising a vessel having a gas inlet, a particulate material inlet, and a gas and particulate material outlet, which has an operating pressure of about 15 psig or less. The operation member includes an operation portion and an abutting portion, wherein a distance from the operation portion to a rotating fulcrum is longer than a distance from the abutting portion to the rotating fulcrum. Said grippers have open insertion openings for the retaining bolts in directions facing away from each other. The charging station and the robotic devices are both provided with communications capabilities and a protocol by which they can negotiate to find a time slot in which the device can be recharged, as well as determining a correct connector and a battery type. The system includes at least one device for switching radio frequency signals, and the device includes at least a first MOS transistor for selectively interrupting or transmitting the signals between at least first and second terminals of the system as a function of a control signal.