Removal device for removing gas bubbles and/or dirt particles from a liquid in a liquid conduit system or for removing a second liquid from a first liquid in the conduit system, the removal device comprising: - a main channel for a main flow, the main channel having an entry and an exit which are configured to be connected to the conduit system, - a housing which defines an inner space, - at least one supply channel (36A,36B) extending from the main channel to the inner space, - at least one return channel extending from the inner space back to the main channel, directly or indirectly via a return chamber, - a quiet zone in the inner space in which in use the liquid has a substantially smaller velocity than in the main channel, the quiet zone being configured to allow dirt particles or a relatively heavy liquid to settle at a lower end of the housing and/or gas bubbles or a relatively light liquid to rise to an upper end of the housing, wherein the at least one supply channel branches off from the main channel at a branch-off location, and wherein at the branch-off location a local widening part of the main channel is provided which extends around the main channel, the local widening part being constructed to guide an outer part of the main flow which flows through the main channel into the local widening part and subsequently into the at least one supply channel, wherein directly downstream of the local widening part a local narrowing part of the main channel is provided having a sharp edge which is directed against the direction of the main flow, which narrowing part is constructed to guide an outer portion of the main flow into the local widening part, wherein the sharp edge extends circumferentially around the main channel over an angle of at least 180 degrees. - a main channel for a main flow, the main channel having an entry and an exit which are configured to be connected to the conduit system, - a housing which defines an inner space, - at least one supply channel (36A,36B) extending from the main channel to the inner space, - at least one return channel extending from the inner space back to the main channel, directly or indirectly via a return chamber, - a quiet zone in the inner space in which in use the liquid has a substantially smaller velocity than in the main channel, the quiet zone being configured to allow dirt particles or a relatively heavy liquid to settle at a lower end of the housing and/or gas bubbles or a relatively light liquid to rise to an upper end of the housing, wherein the at least one supply channel branches off from the main channel at a branch-off location, and wherein at the branch-off location a local widening part of the main channel is provided which extends around the main channel, the local widening part being constructed to guide an outer part of the main flow which flows through the main channel into the local widening part and subsequently into the at least one supply channel, wherein directly downstream of the local widening part a local narrowing part of the main channel is provided having a sharp edge which is directed against the direction of the main flow, which narrowing part is constructed to guide an outer portion of the main flow into the local widening part, wherein the sharp edge extends circumferentially around the main channel over an angle of at least 180 degrees. wherein the at least one supply channel branches off from the main channel at a branch-off location, and wherein at the branch-off location a local widening part of the main channel is provided which extends around the main channel, the local widening part being constructed to guide an outer part of the main flow which flows through the main channel into the local widening part and subsequently into the at least one supply channel, wherein directly downstream of the local widening part a local narrowing part of the main channel is provided having a sharp edge which is directed against the direction of the main flow, which narrowing part is constructed to guide an outer portion of the main flow into the local widening part, wherein the sharp edge extends circumferentially around the main channel over an angle of at least 180 degrees.