Method and apparatus for cleaning pipe lines

Claim 1

A METHOD OF CLEANING A CLOGGED PIPE LINE BY MEANS OF A SOLVENT AND A CARRIER FOR THE SOLVENT, WHICH METHOD COMPRISES ABRUPTLY RELEASING FROM A REGION OF SUPERATMOSPHERIC PRESSURE A STREAM OF LIQUEFIED GAS CONTAINING A SOLVENT FOR SOFTENING THE MATERIAL WITH WHICH THE PIPE LINE IS CLOGGED, EXPANDING THE LIQUEFIED GAS THE SOLVENT CONTAINED THEREIN INTO THE PIPE LINE WITH THE PRESSURE IN THE PIPE LINE SUBSTANTIALLY LESS THAN THE LIQUEFACTION PRESSURE OF THE GAS AT THE EXISTING TEMPERATURE WHEREBY THE GAS CHANGES SUDDENLY TO THE VAPOR PHASE WITH RESULTING ATOMIZING OF THE SOLVENT, CAUSING A WAVE FRONT OF THE VAPOR AND ATOMIZED SOLVENT TO FLOW INTO THE PIPE LINE AND UP TO THE REGION OF OBSTRUCTION, CARRYING THE SOLVENT INTO CONTACT WITH THE OBSTRUCTION BY MEANS OF THE WAVE FRONT AND SUPPLYING ADDITIONAL VAPOR AND SOLVENT TO THE PIPE LINE AND TO THE OBSTRUCTION AT PROGRESSIVELY HIGHER PRESSURES TO EXERT FORCE AGAINST THE OBSTRUCTION, INCREASING THE PRESSURE UP TO THE FULL PRESSURE OF THE LIQUEFIED GAS OR SUCH LESSER PRESSURE AS WILL BREAK THROUGH THE OBSTRUCTION, AND CONTINUING THE FLOW OF CARRIER AND SOLVENT THROUGH THE REGION OF THE OBSTRUCTION AFTER BREAK-THROUGH OF THE OBSTRUCTION TO OPEN UP THE INSIDE CROSS-SECTION OF THE PIPE LINE BY THE COMBINED SOFTENING ACTION OF THE SOLVENT AND MECHANICAL EROSION BY THE CARRIER.

Claim 2

A METHOD OF CLEANING A CLOGGED PIPE LINE BY MEANS OF A SOLVENT AND A CARRIER FOR THE SOLVENT, WHICH METHOD COMPRISES ABRUPTLY RELEASING FROM A REGION OF SUPERATMOSPHERIC PRESSURE A STREAM OF LIQUEFIED GAS CONTAINING A SOLVENT FOR SOFTENING THE MATERIAL WITH WHICH THE PIPE LINE IS CLOGGED, EXPANDING THE LIQUEFIED GAS THE SOLVENT CONTAINED THEREIN INTO THE PIPE LINE WITH THE PRESSURE IN THE PIPE LINE SUBSTANTIALLY LESS THAN THE LIQUEFACTION PRESSURE OF THE GAS AT THE EXISTING TEMPERATURE WHEREBY THE GAS CHANGES SUDDENLY TO THE VAPOR PHASE WITH RESULTING ATOMIZING OF THE SOLVENT, CAUSING A WAVE FRONT OF THE VAPOR AND ATOMIZED SOLVENT TO FLOW INTO THE PIPE LINE AND UP TO THE REGION OF OBSTRUCTION, CARRYING THE SOLVENT INTO CONTACT WITH THE OBSTRUCTION BY MEANS OF THE WAVE FRONT AND SUPPLYING ADDITIONAL VAPOR AND SOLVENT TO THE PIPE LINE AND TO THE OBSTRUCTION AT PROGRESSIVELY HIGHER PRESSURES TO EXERT FORCE AGAINST THE OBSTRUCTION, INCREASING THE PRESSURE UP TO THE FULL PRESSURE OF THE LIQUEFIED GAS OR SUCH LESSER PRESSURE AS WILL BREAK THROUGH THE OBSTRUCTION, AND CONTINUING THE FLOW OF CARRIER AND SOLVENT THROUGH THE REGION OF THE OBSTRUCTION AFTER BREAK-THROUGH OF THE OBSTRUCTION TO OPEN UP THE INSIDE CROSS-SECTION OF THE PIPE LINE BY THE COMBINED SOFTENING ACTION OF THE SOLVENT AND MECHANICAL EROSION BY THE CARRIER.