The invention relates to a process for separating off solid particles, in particular coke particles, from a water phase by means of gravity in a plant for generating hydrocarbons by cracking a hydrocarbonaceous feed, and also to a device for carrying out the process. In contrast to the prior art, the water phase is taken off predominantly from a point above the column bottom B via the outlet A. The first gravity separator 2 which is constructed as a multistage settling tank 2 is situated not beneath, but next to, the scrubbing water column 1. The bottom phase of the scrubbing water column 1 already acts as a part of the first gravity separator 2. Thus, via the outlet 5 in the column bottom B, a heavy water phase which is loaded with coke particles is already taken off and passed into the second gravity separator 3. This heavy water phase is further treated, together with the heavy water phase which is loaded with coke particles from the recesses 6 of the multistage settling tank 2. In this embodiment of the invention, the feed rate into the multistage settling tank 2 need not be controlled as in the prior art. The multistage settling tank 2 and the bottom phase of the quench column 1 form a communicating liquid system in which the same level of the water phase is established.