Abstract: An apparatus for cooling hot gas comprises: (i) a vertical elongated vessel provided with a cooling medium compartment comprising in use a first cooling medium, an inlet to supply fresh first cooling medium and a outlet for discharge of used first cooling medium, the vessel further provided with an inlet for hot gas and an outlet for cooled gas, at least one heat exchange tube, which heat exchange tube is positioned in the cooling medium compartment (and fluidly connects the inlet for hot gas and the outlet for cooled gas, (ii) said cooling medium compartment further comprising a vertical and centrally positioned open ended downcomer wherein said heat exchange tube is positioned in a space between the downcomer and the vessel wall, (iii) and wherein the heat exchanger tube is mounted at its upstream end in a tube plate and wherein the tube plate is provided with means to supply a second cooling medium to the exterior of the upstream end of the heat exchanger tube, means to discharge the used second cooling me

Abstract: A method to control a process, wherein the status of the process can be altered by a multitude of actions, wherein the action is controlled by basic control units, wherein at least one basic control unit is coordinated by at least one group control unit and wherein this basic control unit has the following functions: (b1) means to receive and priority handle a request for a basic control action from one or more group control units or from the operator to be performed by said basic control unit, (b2) means to receive and transform information from the process and/or output from basic control unit(s) and/or output from group control unit(s) into a permit required to start or to continue to execute said action, (b3) means to receive lockouts from basic control unit(s) and/or from group control unit(s) and/or from the operator and/or from the basic control unit itself to prevent the start or to initiate the termination of said action and force the default status or shut-down sequence of the basic control unit unt