System, method and apparatus for manufacturing boiler tubes

Abstract

A method for manufacturing boiler tubes includes the steps of removing end caps from a plurality of tubes, the plurality of tubes including at least a first tube and a second tube, cleaning an outer surface of the first tube and the second tube, forming a weld preparation on an upstream end of the first tube, forming a weld preparation on a downstream end of the second tube, welding the upstream end of the first tube to the downstream end of the second tube to form a butt weld, to produce a long tube, and with an automated device, measuring a parameter of at least the first tube and the second tube. The steps of removing the end caps, cleaning the outer surface of the tubes, forming the weld preparations, welding the first tube to the second tube, and measuring the parameter are performed autonomously.

What is claimed is: 
     
         1 . A method for manufacturing boiler tubes, comprising the steps of:
 removing end caps from a plurality of tubes, the plurality of tubes including at least a first tube and a second tube;   cleaning an outer surface of the first tube and the second tube;   forming a weld preparation on an upstream end of the first tube;   forming a weld preparation on a downstream end of the second tube;   welding the upstream end of the first tube to the downstream end of the second tube to form a butt weld, to produce a long tube; and   with an automated device, measuring a parameter of at least the first tube and the second tube;   wherein the steps of removing the end caps, cleaning the outer surface of the tubes, forming the weld preparations, welding the first tube to the second tube and measuring the at least one parameter are performed autonomously and without storing offline between the steps.   
     
     
         2 . The method according to  claim 1 , further comprising the step of:
 receiving, via a conveyor, the plurality of tubes for removal of the end caps.   
     
     
         3 . The method according to  claim 1 , wherein:
 the parameter includes at least one of tube dimensions, wall thickness, hardness and chemistry.   
     
     
         4 . The method according to  claim 3 , further comprising the steps of:
 comparing the measured value for the parameter of the first tube to a required value for the parameter stored in memory; and   offloading the first tube if the measured value for the parameter does not match the required value.   
     
     
         5 . The method according to  claim 4 , further comprising the step of:
 with an automated printing system, receiving values for the measured parameters of the first tube and the second tube; and   printing identifying information on the outer surface of the first tube and the second tube, the identifying information including at least a value for at least one of the measured parameters.   
     
     
         6 . The method according to  claim 5 , further comprising the step of:
 prior to forming the weld preparation on the first tube and the second tube, cutting at least one of the first tube and the second tube to a predetermined length.   
     
     
         7 . The method according to  claim 6 , further comprising the step of:
 after welding the first tube to the second tube, inspecting the butt weld for defects utilizing a digital, in-line x-ray system with automated defect recognition.   
     
     
         8 . The method according to  claim 7 , wherein:
 each of the steps is performed autonomously, as an inline part of a long tube manufacturing process, without intervention by a human operator.   
     
     
         9 . The method according to  claim 1 , wherein:
 the step of removing the end caps includes, for each end cap, bringing a centering device into engagement with the end cap, extending a bisected blade from the centering device such that the bisected blade pierces the end cap and opposed blade portions of the blade bias away from one another, and retracting the blade into the centering device to pull the end cap from the tube.   
     
     
         10 . The method according to  claim 1 , wherein:
 the step of cleaning the outer surface of the first tube and the second tube is carried out via laser ablation.   
     
     
         11 . The method according to  claim 1 , further comprising the step of:
 after welding the first tube to the second tube, inspecting the butt weld for defects; and   if a defect is detected, reversing a first conveyor to move the first tube and the second tube to a repair station, cutting through the butt weld at the repair station, machining new weld preparations on the first tube and the second tube, reversing a second conveyor to move the first tube and the second tube back to a welding station and, at the welding station, butt welding the first tube to the second tube.   
     
     
         12 . An autonomous apparatus for the manufacture of long boiler tubes, the apparatus comprising:
 a decapping station configured to remove end caps from ends of a first tube and a second tube;   a cleaning station configured to remove a contaminant surface layer from an outer surface of the first tube and the second tube;   a weld preparation station configured to form a weld preparation in at least an upstream end of the first tube and a downstream end of the second tube;   a joining station configured to butt weld the first tube to the second tube; and   at least one control unit configured to control operation of the decapping station, cleaning station, weld preparation station and joining station without intervention by a human operator after the first tube and second tube are received at the decapping station, and to control material flow of the first tube and the second tube from the decapping station to the joining station.   
     
     
         13 . The apparatus of  claim 12 , further comprising:
 an inspection and verification station configured to measure a plurality of properties of the first tube and the second tube and to compare the measured property values to target property values stored in memory;   wherein the plurality of parameters include at least a chemistry, wall thickness and hardness.   
     
     
         14 . The apparatus of  claim 13 , further comprising:
 an identification station controlled by the control unit, the identification station being configured to print identifying information on the outer surface of the first tube and the second tube.   
     
     
         15 . The apparatus of  claim 14 , further comprising:
 a cutting station controlled by the control unit, the cutting station being configured to retrieve a tube length specification stored in memory and to cut at least one of the first tube and the second tube according to the tube length specification.   
     
     
         16 . The apparatus of  claim 12 , further comprising:
 a weld testing station configured to verify whether the weld produced at the welding station meets predetermined quality standards;   wherein the control unit is configured to control operation of the weld testing station and movement of the first tube and the second tube to and from the weld testing station.   
     
     
         17 . The apparatus of  claim 16 , further comprising:
 a repair station intermediate the weld testing station and the joining station and controlled by the control unit, the repair station having a saw for cutting through the butt weld and a rotating table having a machining device for machining a weld preparation on upstream and downstream ends of at least one of the first tube and the second tube;   wherein the control unit is configured to control flow of at least the first tube from the weld testing station, to the repair station, and to the joining station to repair a weld that has been determined to be defective by the weld testing station.   
     
     
         18 . An autonomous system for the manufacture of long boiler tubes, comprising:
 a decapping device configured to remove end caps from ends of a first tube and a second tube;   a cleaning device in line with the decapping device and being configured to remove a contaminant surface layer from an outer surface of the first tube and the second tube via laser ablation;   a weld preparation device configured to machine a weld preparation in at least an upstream end of the first tube and a downstream end of the second tube after the contaminant surface layer is removed;   a joining device configured to weld the first tube to the second tube; and   at least one control unit configured to automatically control operation of the decapping device, cleaning device, weld preparation device and joining device, and to control material flow of the first tube and the second tube from the decapping device to the joining device to produce a long boiler tube.   
     
     
         19 . The system of  claim 18 , further comprising:
 a weld inspection device configured to inspect a weld between the first tube and the second tube, the weld inspection device including a digital, in-line x-ray system with automated defect recognition.