Abstract: A process for the reduction of aromatic nitro compounds to amino compounds in the liquid phase using iron as reducing agent, which comprises carrying out the reduction continuously such that the reducing iron, based on the amount of nitro compound present in the reactor, is present in an amount substantially in excess of the stoichiometric amount, and effecting the continuous removal of the reaction products such that the substantial excess of reducing iron is also constantly present in the reactor during the reduction.

Abstract: A filtration system having an intermittently moving belt on which is deposited a suspension to form a filter cake. A press is provided above the belt comprising one or more pressure cushions, and suction chambers are disposed below the belt. A control system coupled to the cushions and the chambers controls application of pressure to the former and suction to the latter to press the cushions down on the filter cake formed on the belt and to draw off moisture from the compressed cake, the action of applying pressure and suction halting movement of the belt. After filtering the cake the pressure and suction are removed allowing the belt to move forward and another filtration cycle to start on the next section of the filter cake formed on the belt.

Abstract: Method and apparatus for the liquid treatment of filter cakes formed as a layer on a moving filter web. The method comprising removing portions of the cake from the web by agitators having vanes which break up part of the cake on the filter and move the portions into a cover over the agitators where treatment liquid is injected to treat the portions removed from the web. The treated portions are then returned to the moving web at substantially the same place from whence they were removed.

Abstract: A method and apparatus for reducing the liquid content of a layer of material formed on a belt filter where a differential gas pressure is produced across the layer of material with a maximum pressure at the exposed surface thereof and a minimum pressure at the filter belt and the layer of material is mechanically compressed against the filter by a gas permeable pressure surface.