Cooling of tube containing reactants

A reactor assembly comprising a reactor, wherein the reactor is configured for hosting a fluid to be treated with light source radiation selected from one or more of UV radiation, visible radiation, and IR radiation, wherein the reactor comprises a reactor wall which is transmissive for the light source radiation, wherein:

• the reactor is a tubular reactor, and wherein the reactor wall defines the tubular reactor;
• the tubular reactor is configured in a tubular arrangement;
• the reactor assembly further comprises a reactor support element, wherein the reactor support element comprises a track, wherein the track partly encloses the tubular reactor, wherein the reactor support element comprises a thermally conductive element, and wherein the tubular reactor is configured in thermal contact with the thermally conductive element;
• wherein the tubular arrangement comprises a coiled tubular arrangement, wherein the tubular reactor is helically coiled, and wherein the track is helically coiled;
• wherein the reactor assembly comprises a photoreactor assembly, wherein the reactor assembly further comprises a light source arrangement comprising a plurality of light sources configured to generate the light source radiation, wherein the reactor wall is configured in a radiation receiving relationship with the plurality of light sources;
• wherein the reactor support element comprises a support element surface comprising a cavity, wherein the cavity defines the track;
• wherein a surface of the track corresponds to at least part of an outer surface of the reactor wall.