Abstract: A reaction block assembly of reaction vessels for conducting chemical reactions under pressure. The assembly includes a heat conductive reactive block having reaction vessel receiving openings formed in the block. A heat exchanger is mounted in heat transfer engagement with some of the exterior walls of the reaction block. The heat exchangers can operate in different modes, to provide a heat differential across the reaction block. A reaction vessel is positioned in each reaction vessel receiving opening in the block. A cap is attached to each reaction vessel and a cannula opening is formed in each cap. A cannula passage is connected at one end to a cannula opening in each cap and it has a septum at the other end. A valve controls each cannula passage. An operating mechanism is provided for opening and closing each cannula passage controlling valve. The reaction block assembly may be used to determine when the reaction of a solution in a reaction vessel is completed.

Abstract: An array of reaction assemblies for heating and cooling a plurality of reaction vessels. Each reaction vessel assembly including a heat conductive reaction block having an exterior wall and a reaction vessel receiving cavity formed in the block inwardly of the exterior wall. A thermoelectric module is mounted in heat transfer engagement with the exterior wall of the heat conductive reaction block. A fluid heat exchange element is mounted in heat transfer engagement with the thermoelectric module. The thermoelectric module has its junctions to selectively remove heat from the exterior wall of the reaction block or to supply heat to this exterior wall. Each thermoelectric module has thermoelectric junctions cascaded for increased heating and cooling range and a plurality of these junctions to increase capacity.