Sootblower nozzle assembly with nozzles having different geometries

A lance tube nozzle block for a sootblower, comprising:

• a nozzle block body defining a longitudinal axis, a hollow interior, a distal end, and a proximate end with the proximate end receiving the cleaning medium;
• a downstream nozzle positioned on the nozzle block body, the downstream nozzle having a first inlet end, a first outlet end, and a first throat positioned between the first inlet end and the first outlet end, the dimensions of the first inlet end, the first outlet end, and the first throat defining a first geometry;
• and
• an upstream nozzle positioned longitudinally from the position of the downstream nozzle farther from the distal end than the position of the downstream nozzle, the upstream nozzle having a second inlet end, a second outlet end, and a second throat positioned between the second inlet end and the second outlet end, the dimensions of the second inlet end, the second outlet end, and the second throat defining a second geometry, the first geometry and the second geometry being selected to optimize the cleaning energy of the nozzle block,
• the cleaning medium flowing in the direction of the longitudinal axis from the proximate end towards the distal end through the nozzle block body hollow interior and entering the downstream and upstream nozzles through the respective first and second inlets and discharging from the downstream and upstream nozzles from the respective outlet ends in directions generally perpendicular to the longitudinal axis.