Tubular furnace for cracking hydrocarbon(s) in the presence of steam

摘要

Tubular furnace for heating by radiation for the thermal decomposition of hydrocarbons in the presence of water vapour including a radiation zone with at least two parallel layers of vertical tubes circulating a mixture of hydrocarbons and steam, each of the two layers being heated from two sides by flows of combustion gases which are rising overall. There is at least one row of burners arranged vertically in the lower part of the radiation zone and emitting flows of combustion gases in the space between the two layers. The radiation zone has a lower principal zone (1) of higher thermal transfer and an upper secondary zone (2) with a relatively low thermal transfer above the principal zone. The secondary zone also acts as a collection zone for the combustion gases to evacuate them through at least one convection zone (3). The principal and secondary zones are crossed by the layers of tubes. The furnace also includes a body (10) of relatively small thickness relative to its other dimensions, placed between the layers of tubes and between the principal and secondary zones to form a restriction which accelerates the combustion gases and allows their transfer from the principal zone to the secondary zone through at least two elongated sections on either side of the body.