Abstract: With a system for synthesis gas production, having a reactor as well as a gas cooler/purifier connected with it in terms of flow, a solution is supposed to be created, with which the most compact possible connection between reactor, on the one hand, and the gas cooler or purifier, on the other hand, is made possible, whereby heat expansions that occur due to different temperatures are absorbed. This is accomplished in that the connection between reactor (1) and gas cooler/purifier (7) is formed by a horizontal connection piece (5) having a throttle element (6) configured as a Venturi element.