Abstract: An apparatus for pneumatically conveying bulk material in particular bulk material which is difficult to handle includes a conveyor line having a plurality of conveyor line sections for transporting the bulk material. Each of the conveyor line sections comprises a rigid outer pipe and an elastic inner pipe of an outer diameter which is smaller than the inner diameter of the outer pipe in pressureless state. The connection of adjacent conveyor line sections is attained by a sectional ring which is placed over each axial end of the outer pipe and about which the elastic pipe is folded outwardly, a flange element arranged between the thus shaped axial ends of adjoining conveyor line sections, and external brace elements extending between successive flange elements for bracing the latter so as to connect adjoining conveyor line sections in pressure-sealed manner.

Abstract: An apparatus for pneumatically conveying bulk material includes a conveyor line for transporting the bulk material and a secondary line which carries clean gas and is sectionized by spaced three-way/two-way directional control valves. Each control valve is actuated by a pressure transmitter which compares the actual pressure in the conveyor line with the desired pressure in a third line carrying a fluid at a desired pressure decreasing in downstream direction in accordance with the pressure drop in the conveyor line during normal operation. A communication between the conveyor line and the second line is provided by respective branch lines which define the third connection of the control valves and are multiply connected to the conveyor line.

Abstract: An apparatus for pneumatically conveying bulk material includes a conveyor line for transporting the bulk material and a secondary line which carries clean gas and is multiply connected via branch line and a plurality of check valves with the conveyor line for allowing introduction of clean gas when the pressure difference as measured between adjacent pressure transmitters exceeds a predetermined value. Adjacent pressure transmitters are operatively connected with a differential pressure switch which actuates a valve regulating the flow of clean gas through the branch line. The differential pressure switch opens the valve as soon as the pressure difference exceeds the predetermined value.

Abstract: A transport conduit for bulk material is formed of a rigid outer tube and an elastic inner tube of substantially smaller diameter. The inner tube is hermetically sealed at each of its ends to the conduit section so as to form a closed annular chamber between the inner elastic tube and the rigid outer tube. Communicating through the wall of both the outer and inner elastic tubes are relief and check valves sealed with respect to the elastic inner tube so as to maintain the integrity of the annular chambers. The valves are connected to a secondary gas supply from which air under pressure is directed into the conduit to assist in the transport of the bulk material. The annular chambers are serially connected by bridging tubes passing from one section to the adjacent section, thereby interconnecting each of the annular chambers in an outer parallel conduit to permit atmospheric air to move serially through them from one end of the transport conveyor to the other.

Abstract: A slide valve for a container with an upright supply of bulk material has a sealing element with a sealing face, a tubular slider movable relative to an inlet opening between an open position in which it releases an annular gap for passing the bulk material and a closed position in which it closes the annular gap, and a deflecting cone located under the inlet opening, having a base of a diameter exceeding the diameter of the inlet opening, and serving as a guide for the tubular slider, wherein the tubular slider has a lower end face which is closed and an upper edge which abuts against the sealing face in the closed position and is substantially flush with the conical face of the deflecting cone in the open position, and the sealing face is located above the inlet opening.

Abstract: Conveyor gas is passed through a conveyor conduit to convey bulk material therethrough, while clean gas is passed through a by-pass conduit connected to the conveyor conduit at positions spaced along the length of the conduits. The by-pass conduit can be divided into a plurality of sections by shut-off valves which close in response to a predetermined pressure difference between the two conduits, with a reduced pressure in the conveyor conduit due to a blockage of material therein. Due to the pressure difference, clean gas is transferred from the by-pass to the conveyor conduit at a plurality of said connections between the two conduits, only in the respective section in which there is the pressure difference.