Cooling shield for a liquor injection pipe of a liquor gun, liquor gun system comprising the cooling shield, and method for cooling a liquor injection pipe in a liquor gun system

A liquor gun system comprising:

• a liquor gun comprising a liquor injection pipe for supplying liquor to a combustion chamber of a recovery boiler, the liquor injection pipe comprising a nozzle arranged at a combustion chamber end of the liquor injection pipe, the combustion chamber end of the liquor injection pipe being configured for being inserted into the combustion chamber of the recovery boiler, the nozzle being arranged for ejecting liquor into the combustion chamber of the recovery boiler;
• and
• a cooling shield having a first side edge and a second side edge that extend in a longitudinal direction of the cooling shield, and a first end edge and a second end edge that extend between the first and second side edges, the cooling shield comprising:
• an outside shield wall, and an inside shield wall that are connected along the side edges of the cooling shield,
• a cooling medium space located between the outside shield wall and the inside shield wall, and
• a cooling medium inlet and a cooling medium outlet that are arranged in communication with the cooling medium space, wherein the cooling medium outlet comprises a plurality of openings or pores in the outside shield wall;
• wherein the cooling shield is located at least at the combustion chamber end of the of the liquor injection pipe and covers at least a portion of an upper outer surface of the liquor injection pipe, with the inside shield wall of the cooling shield facing the liquor injection pipe and with the outside shield wall of the cooling shield facing away from the liquor injection pipe.