The concentration of liquid wastes before feeding them to incinerators is also an economical method of treating waste liquids. However, when liquid wastes are concentrated, solids and slurries are formed which are difficult to feed to incinerators using spraying techniques. We can achieve the decomposition of liquid wastes containing slurries using horizontal incinerators. If liquid wastes containing slurry are fed to an incinerator using the spraying method, the nozzle chokes at once. Therefore, we developed a feed mechanism that enables slurries and concentrated liquid wastes to be fed to an incinerator without requiring atomizing.