Abstract: In a pumping apparatus having a flexible diaphragm a disc is arranged for supporting the diaphragm. The support disc has holes through which the pump liquid passes. For preventing the diaphragm from being drawn into the holes plugs are inserted in the holes in such a way that openings or slots are formed which are sufficiently wide for the liquid to flow therethrough but are not wide enough for the diaphragm to be sucked into the support disc. The diaphragm is thus prevented from becoming damaged. Various embodiments of suitable plugs are illustrated which either form the narrow openings in combination with the surrounding wall of the holes in the support disc or are provided with holes or slots in the plug body.

Abstract: The method of mixing solid and liquid substances comprises the steps of keeping the substances in a constant circulation through a mixing tank by pumping the substances through a tank outlet and feeding them back through a tank inlet, discharging ready mixture from the tank, and supplying simultaneously a quantity of substances to the tank that equals the quantity of the ready mixture discharged from the tank. The apparatus for performing the method comprises a loop-type reactor with a reactor housing having inlet means at one end and outlet means at the opposite end, and having a tube socket for introducing the substances into the reactor. A control valve regulates the quantity of substances admitted to the reactor. The inlet means and the outlet means are interconnected by a pipe line, including a circulating pump. The pump keeps the substances in a constant flow through the reactor and the pipe line. A discharge valve is connected to the pipe line for discharging part of the ready mixture.

Abstract: A loop-type reactor with a reactor housing having inlet means at one end and outlet means at the opposite end. Inside the reactor there is a guide tube arranged in the direction of the axis of the inlet means. The inner wall of the reactor is so shaped that the introduced reactants flow through the tube in one direction and are then directed to flow back in the opposite direction through a mixing chamber defined between the outer tube surface and the inner reactor wall. Thus a circulation of the reactants inside the reactor is induced. At the end remote from the inlet means the tube is provided with means for defining an annular space. Openings are provided for connecting the mixing chamber with the annular space, and escape pipes are provided for connecting the annular space with the reactor outlet. After optimal processing the reactants enter through the openings into the annular space and from there through the escape pipes to the reactor outlet.