Abstract: The invention relates to a conveyor for thick substances containing a great deal of solids and having a conveyor pipe (20) which can be filled with the thick substances under pressure and at least one injection point (22, 24) opening into the conveyor pipe (20) to supply a lubricant (83) to the region (84) between the pipe wall and the surface of a plug flow of thick substance (82) being formed in the conveyor pipe (20). In order to center the plug flow (82) inside the conveyor pipe (20) and provide a stable layer of lubricant (83), the invention proposes that the conveyor pipe (20) have at least one annular waist at a distance from and downstream of the injection point (22, 24) formed by a collar or shoulder-like projection (62') inside the conveyor pipe (20).

Abstract: A process and device are disclosed for determining by a measurement technique the flow rate of a substance conveyed by means of a thick matter piston pump (1) through a delivery pipe (22). The thought at the basis of the invention is that the filling level of the delivery cylinder, which is required for accurately determining volumetric flow, may be inferred from the variations of the pressure in the delivery pipe. Feeding pressure in the delivery pipe (22) is thus continuously or periodically measured at predetermined time intervals by means of a pressure sensor (54). The interval between successive pressure strokes, used to determined the number of frequency of strokes, as well as the filling level of the delivery cylinder, used to determine the actual delivery volume per pressure stroke, are both derived from the time-dependent amplitude characteristic of the measured delivery pressure.