Patent CA-2568065-A1 (CA)
Inventor: SCHWARTZ ERWIN
IPC: F28G1/00
Filed: 2006-11-16
Abstract: Pig Cleaning system for a Mechanical Cleaning of Rectangular or Square Channeled Heat Exchangers.     Pig Cleaning for Heat Exchangers with Rectangular Channels for Waste Water or Pulp and Paper or any other liquids.      For the purpose of Surface Fouling removal and for Mechanical cleaning with Insertion and Catching system for the Pig Cleaning, Via a Pig Brush/Sponge/Foam or other material designed for Rectangular channels.     The system has a Launching & Retrieval of the Pig Cleaning System.   The system works with Rectangular Channeled Heat Exchangers that have nozzles which assures a continues same Rectangular channel size dimension for the full flow length.      Advantages: 1- This set up allows for cleaning via a "Pig" with out a need for Sludge main flow DRAINAGE.   2- This set up allows for cleaning via a "Pig" with out opening the DOORS. 3- This set up allows for cleaning via a "Pig" the Internals of a Rectangular channeled Heat exchanger, to reduce the Fouling and improve the Heat Exchangers efficiency.  4- It can be added to any DDI standard Dia flange. 5- It can be used even in the Water side. 6- This set up allows for launching of the Pig and for Extraction/Catching it too, with the same parts (reverse order). 7- It avoids the risk of "loosing" the Pig in the pipes, or the pig being stuck in a 4"  pipe. 8- It allows for having a clean (no liquid) working area, to insert and remove the Pig.  For the benefit of the Technicians, the cavity of the insertion / removal of the Pig could be emptied and cleaned with fresh water. 9- It allows for a NO ABSTRACTION IN THE FLOW of the Sludge, while the process is on. And being able to Launch and Catch the Pig, when the cleaning process is in use. 10- Practical modifications that can be designed and manufactured by DDI and Valves that are standard in the market.     It includes as follows:   AT = Combined Flange. To connect the T Flange to the Rectangular Valve.  T and Pig-BAR = Bars welded Perpendicular to the Flat Flange (combined set).     It could be rotated.   It is used to Push the Pig into the Rectangular Valve Channel in the Inlet and to Catch the Pig at the Outlet. Or can be flipped to the back flat side of the Pig-Bar, for non obstructed flow in normal operation. (Then the bars will stick upwards, outside from the T).      Optional = 90 deg, RECTANGULAR Bend Pipe. To lead the pig flow sideways or upwards, if there is no space to extend further away from the Heat Exchanger.     ng- a Rectangular "Sponge" or "Swab" with different weights.     Process of Cleaning via a "Pig":   Each side or each liquid can have this process.     Each Sludge LIQUID has 2 SET of assemblies. One for Launching in the INLET  (on top preferred if possible), plus one for Catching the Pig in the OUTLET  (in the bottom preferred).     A) Stop the Pumps.   B) Close both Valves A and B (in the TOP and BOTTOM too of the HX). C) Drain the Left over sludge inside the T, and clean, if you want, via fresh water flow into the 2" (or other size) T inlet on the side, drained via the 2"  drainage in the bottom. This allows for a clean cavity area for the Insertion of the Pig in the INLET  of the Heat Exchanger, and later to remove the Pig in the OUTLET of the Heat Exchanger. D) Remove from the top of the T, the 8" (or other size) Flat Flange (which is required in order to have no abstraction of flow in regular process flow).  E) Insert the Pig. Push it by hand into the "A Valve Rectangular (Example: a 3.25" x 8", and you set the pig with the 6.5" on the bottom, 3.5" high, and guide it in the direction of the 7.5" length).   F) Insert the Pig-BAR, which is welded perpendicular to the Flat Flange.     In the INLET direct the horizontal bar of the Pig-BAR, inside the T, towards the Heat Exchanger, pushing the Pig into the "A Valve 3.25" x 8" for example, to help in Launching the Pig correctly (which in turn is connected to the 8"&6" (or other size) combined Flange and in turn is connected to the Heat Exchanger directly).     The set up in the OUTLET is done by reversing the direction of the Pi2-Bar.     In the OUTLET direct the horizontal bar of the Pig-BAR towards the 8" (or other size) Dia round Valve (away from the Heat Exchanger) It is required to catch the Pig and avoid the Pig from stacking in the pipes down the stream.  The 8" (or other size) Dia round Valve B, in turn is connected to the 8" to 4"    (for example) Reducer or to a 90 deg bend, and then to the process piping.     G) Open Valves. In the order of the flow process.  H) Start Pump.     I) Wait, till the estimated time that the Pig has arrived to the Pig-BAR in the Outlet.   J) Close Pump.  K) Close Valves.   L) Drain the sludge inside the T in the OUTLET only of the Heat Exchanger, clean if desired via fresh water flow in the 2" T inlet on the top, drained via the 2" drainage in the bottom. This allows clean cavity area for the REMOVAL of the Pig in the OUTLET of the Heat Exchanger.   M) Remove the Pig-BAR and Remove the Pig too from the OUTLET.  N) Remove the Pig-BAR from the INLET.  O) PUT BACK the Flat (8" or other size) Flanges on the top of the T. Both in the INLET and in the OUTLET.     This process could be repeated (A-to-N) if required with the harder Pig (3 lbs, or other weight).