A powder storage apparatus 41 includes: a container 42 having a powder inlet 18A, a powder outlet 10A, and a gas outlet 18B; and a tube 70 connected to the powder inlet 18A. If A.sub.S [m.sup.2] is a cross-sectional area of a cross section perpendicular to an axis of the tube 70 at a bottom end 70b of the tube 70 and A.sub.B [m.sup.2] is a cross-sectional area of the gas outlet 18B, the following expression is satisfied.

A.sub.S/A.sub.B<4

A powder storage apparatus 41 includes: a container 42 having a powder inlet 18A, a powder outlet 10A, and a gas outlet 18B; and a tube 70 connected to the powder inlet 18A. If A.sub.S [m.sup.2] is a cross-sectional area of a cross section perpendicular to an axis of the tube 70 at a bottom end 70b of the tube 70 and A.sub.B [m.sup.2] is a cross-sectional area of the gas outlet 18B, the following expression is satisfied.

A.sub.S/A.sub.B<4

A method changes the material from a feed mixture to a subsequent mixture in a feed device of an extruder, the method comprising the steps of detecting a change request for changing the material, emptying a mixing area of a mixing device of the feed device, identifying the completion of the emptying of the mixing area, and filling the mixing area of the mixing device with the subsequent mixture after the completion of the emptying has been identified.

A method changes the material from a feed mixture to a subsequent mixture in a feed device of an extruder, the method comprising the steps of detecting a change request for changing the material, emptying a mixing area of a mixing device of the feed device, identifying the completion of the emptying of the mixing area, and filling the mixing area of the mixing device with the subsequent mixture after the completion of the emptying has been identified.

A self-cleaning dosing apparatus includes a material hopper for containing pellets of material, a feed screw, a first material outlet through which pellets of material fall by gravity onto a first end of the feed screw for the feeding of pellets to a process machine. A second material outlet is located beneath the first end of the feed screw, with a slide gate blocking the second material outlet. A pneumatic piston is provided for pulling the slide gate to unblock the second material outlet, and a Venturi pump is located under the second material outlet for pulling pellets through the second material outlet when the slide gate is opened.

A self-cleaning dosing apparatus includes a material hopper for containing pellets of material, a feed screw, a first material outlet through which pellets of material fall by gravity onto a first end of the feed screw for the feeding of pellets to a process machine. A second material outlet is located beneath the first end of the feed screw, with a slide gate blocking the second material outlet. A pneumatic piston is provided for pulling the slide gate to unblock the second material outlet, and a Venturi pump is located under the second material outlet for pulling pellets through the second material outlet when the slide gate is opened.

Device for dispensing a food item into a hot fluid comprises a bowl having a permanent base and a movable plate positioned about the permanent base. A bottom of the bowl defines an opening for receiving a shaft extending therethrough. The shaft is coupled to the movable plate. A shank is selectively engaged with the bowl, the shank having a handle at a proximal end thereof. A lever is pivotably attached to the shank. The pivotal attachment is spaced apart from the bowl. The lever is detachably coupled to the shaft to impart translation of the movable plate. During operation, the lever is manipulated from a first position to a second position to push the shaft to move the movable plate to thereby eject the food item out of the bowl and into a hot fluid.

Device for dispensing a food item into a hot fluid comprises a bowl having a permanent base and a movable plate positioned about the permanent base. A bottom of the bowl defines an opening for receiving a shaft extending therethrough. The shaft is coupled to the movable plate. A shank is selectively engaged with the bowl, the shank having a handle at a proximal end thereof. A lever is pivotably attached to the shank. The pivotal attachment is spaced apart from the bowl. The lever is detachably coupled to the shaft to impart translation of the movable plate. During operation, the lever is manipulated from a first position to a second position to push the shaft to move the movable plate to thereby eject the food item out of the bowl and into a hot fluid.

In some examples, a build material recycling system of a three-dimensional (3D) printer can include a build material transport system of the 3D printer, a build material recycling device of the 3D printer that includes a fluidizing membrane and is connected to the build material transport system, and a recycled build material hopper of the 3D printer connected, via the build material transport system, to the build material recycling device.

In some examples, a build material recycling system of a three-dimensional (3D) printer can include a build material transport system of the 3D printer, a build material recycling device of the 3D printer that includes a fluidizing membrane and is connected to the build material transport system, and a recycled build material hopper of the 3D printer connected, via the build material transport system, to the build material recycling device.