A method is provided for feeding in and transporting material in a pneumatic conveying system for material, which conveying system includes at least one input point of material, a material conveying pipe, which can be connected to the input point, and a material container, in which the material being transported is separated from the transporting air, and also a device configured to product a partial vacuum/a pressure difference and/or a transporting air current in the conveying pipe at least during the transporting of the material, which device includes at least one partial-vacuum source. In the method, the suction side of the partial-vacuum source is connected to act in the conveying pipe and onwards to an input point arranged in the conveying pipe, or to act at least in the feeder channel that is between the conveying pipe and the input point, in which case the input point, or at least the feeder channel, intended for emptying that is closest to the material container in the conveying direction of the material empties and the material displaces into the conveying pipe, that arranged in the input point, on the inside of said input point and on the opposite side of the input aperture with respect to the feeder channel, is a shut-off element, which is moved by means of the suction produced by the partial-vacuum source from a first position, in which the shut-off element does not make the pathway through the input aperture into the feeder channel essentially smaller, into a second position, in which the shut-off element does make the pathway through the input aperture into the feeder channel essentially smaller, when the pressure on the first side, on the feeder channel side, of the shut-off element is smaller than on the second side, on the opposite side with respect to the feeder channel, of the shut-off element. An input point and to a pneumatic material-conveying system are also disclosed.

A system for transporting hazardous particles includes a pneumatic conveyer for conveying the hazardous particles to an exit using a carrier gas; and an input mechanism for conveying the hazardous particles to the pneumatic conveyer. The input mechanism includes a tubular chamber for receiving the hazardous particles; an input pipe extending from the tubular chamber for conveying the hazardous particles into the tubular chamber; and an output pipe extending from a bottom of the tubular chamber. The output pipe includes an upper valve movable between a closed position and an open position, a middle valve movable between a closed position and an open position, and a lower valve. The upper valve and the middle valve, when in their respective closed positions, define a storage chamber for storing a portion of the hazardous particles. The upper valve in its open position allows the portion of the hazardous particles to enter the storage chamber, and the middle valve in its open position allows the portion of the hazardous particles in the storage chamber to flow to the lower valve. The lower valve is configured to convey the hazardous particles from the storage chamber to the pneumatic conveyer in a gradual fashion.

Proposed are a device and a method for recovering and re-injecting excess powder, in which the device includes one or more powder transfer lines transferring powder, a loading chamber loading the powder transferred through a first connecting pipe connected to the powder transfer lines, a storage hopper storing the loaded powder transferred by opening an opening/closing valve disposed at a lower end of the loading chamber, a powder weigher disposed on each side or one side of the loading chamber or the storage hopper, a rotary valve connected to a lower end of the storage hopper and normally discharging the powder stored in the storage hopper, a micro-rotary valve disposed at the storage hopper and recovering the powder exceeding a target supply amount, a recovery chamber connected to the micro-rotary valve and storing the recovered powder, and a controller controlling the rotary valve and the micro-rotary valve.

Powder feeding device and powder transfer method are disclosed. The powder feeding device includes a container including a container body forming a storage space therein; a hopper including a hopper body forming an accommodation space therein; a chamber unit including a chamber housing forming a hollow portion and coupled to the hopper body; a pipe assembly including a container pipe unit which extends from the container and is opened or closed, a hopper pipe unit which is branched from the container pipe unit, is connected to the hopper body, and is opened or closed, and a chamber pipe unit which is branched from the container pipe unit, is connected to the chamber housing, and is opened or closed; and a valve assembly including a coupling valve which is coupled to at least one of the chamber housing and the hopper body and connects/disconnects the storage space to/from the hollow portion.