Steam generator thermal venting

Abstract

The present invention provides a method of removing sludge deposits from steam generator/boiler tube support plates (TSP) using a combination of thermal stress and intermittent pressure pulses wherein the steam generator/boiler is drained to a water level just above a TSP identified as having excessive sludge deposits and/or particularly nonporous sludge known as collars and both thermal stress and high impact pressure pulses are used to dislodge the sludge and/or the collars with the process being repeated for all such TSP and the residue then flushed out by draining or using water lancing methods.

1 . A method of removing sludge deposits from a stem generator comprising the steps of:
 Identifying a location of the sludge deposit;   draining the water level in the steam generator to just above the identified sludge deposit;   allowing the pressure inside the steam generator to increase to a designated level;   venting the steam generator to induce boiling thus creating both thermal and mechanical stress in the sludge deposit; and   draining the boiler to remove the dislodged sludge deposit.   
     
     
         2 . A method as set forth in  claim 1  wherein the step of inducing both thermal and mechanical stress is done without the application of external heat or pressure. 
     
     
         3 . A method as set forth in  claim 2  wherein the sludge deposit is on a tubesheet of the boiler. 
     
     
         4 . A method as set forth in  claim 3  wherein the sludge deposit is an excessive deposit known as a collar. 
     
     
         5 . A method as set forth in  claim 4  wherein the draining of the water level is to a level of between 0 and 24 inches above the identified sludge deposit. 
     
     
         6 . A method as set forth in  claim 5  including the step of identifying the next sludge deposit and draining the water level to the next sludge deposit. 
     
     
         7 . A method as set forth in  claim 6  including the steps of:
 allowing the pressure inside the steam generator to increase to a designated level;   venting the steam generator to induce boiling thus creating both thermal and mechanical stress in the sludge deposit; and   draining the boiler to remove the dislodged sludge deposit.