Show sand sa not blast for cleaning boilers gol lers sand blast tor for cleaning holler boiler tubes Is the latest thing in this imbor tant field put out ont by a concern itt at durlach germany the apparatus consists ot of a length of 0 pipe with a eli pedal nozzle hitched to a compressed air line and a supply of sand the sand to Is claimed to cut away scale and to polish the tube surfaces without damage of any kind and may be employed wherever the pipe can be introduced the air pressure la is from 15 to 80 30 pounds and the consumption about cubit cubic centimeters of free air per minute in 00 seconds the blast Is wit bald to clear away 40 to 60 quere feet feet of scale while with soot of course a far better performance la is scientific american |