Patent ID: 7784433

Claim:
A heat exchanger for cooling reaction gas in an ethylene plant, comprising: two tube plates; heat exchanger tubes through which reaction gas is adapted to flow, wherein ends of said heat exchanger tubes are inserted in respective ones of said tube plates; a jacket surrounding said heat exchanger tubes to form an inner chamber delimited by said tube plates, wherein end chambers adjoin said tube plates for supply of the reaction gas to and withdrawal of the reaction gas from said inner chamber, and wherein water, as cooling agent, is adapted to flow through said inner chamber; a partition disposed in said inner chamber and extending perpendicular to said heat exchangers tubes, wherein said heat exchanger tubes extend through said partition, further wherein said partition divides said inner chamber into two partial chambers that are disposed one after the other in a direction of flow of the reaction gas, further wherein each of said partial chambers is provided with respective supply connectors and outlet connectors for the cooling agent, and wherein said partition allows cooling agent to pass between said partial chambers; and a water/steam drum, wherein a first one of said partial chambers is disposed on a gas inlet side for the reaction gas and is connected via said outlet connectors and withdrawal lines to said water/steam drum, further wherein said first partial chamber is adapted to receive boiling water from said water/steam drum via a supply line and said supply connectors, further wherein said boiling water is adapted to flow through said first partial chamber to said outlet connectors thereof, further wherein a second one of said partial chambers is disposed on a gas discharge side for the reaction gas and is connected via said outlet connector and a withdrawal line with said water/steam drum, and wherein said second partial chamber is adapted to receive feed water via said supply connector, wherein said feed water is adapted to flow through said second partial chamber to said outlet connector thereof.