Shot cleaning systems for heat exchangers

Claim 1

A SHOT CLEANING SYSTEM INCLUDING HEAT EXCHANGER SURFACES, RECOVERY HOPPER MEANS POSITIONED ABOVE HEAT EXCHANGE SURFACES TO BE CLEANED, FIRST AUTOMATICALLY CONTROLLED VALVE MEANS FOR CONTROLLING THE DISCHARGE OF SHOT FROM THE RECOVERY HOPPER MEANS ONTO THE SURFACES TO BE CLEANED, COLLECTING HOPPER MEANS DISPOSED BELOW THE SURFACES TO BE CLEANED, HANDLING MEANS FOR RETURNING SHOT COLLECTED IN THE COLLECTING HOPPER MEANS TO THE RECOVERY HOPPER MEANS, MEANS SENSITIVE TO THE PRESENCE OF SHOT AT A SELECTED HIGH LEVEL IN THE RECOVERY HOPPER MEANS, MEANS SENSITIVE TO A CONDITION IN SAID HANDLING MEANS TO REGULATE OPERATION OF SAID HANDLING MEANS, SAID LAST NAMED MEANS OPERABLE TO STOP SAID HANDLING MEANS WHEN THE SHOT COLLECTED IN SAID COLLECTING HOPPER MEANS HAS BEEN RETURNED BY SAID HANDLING MEANS TO THE RECOVERY HOPPER MEANS, AND ALARM MEANS OPERABLE BY SAID HIGH LEVEL SENSITIVE MEANS SHOULD THE OPERATION OF SAID HANDLING MEANS BE DISCONTINUED WHEN SHOT IS NOT PRESENT AT SAID SELECTED HIGH LEVEL IN SAID RECOVERY HOPPER MEANS.