Tom Bender
08-21-2022, 9:59 PM
Many years ago as a new engineer I was hired by a large foundry. They made lots of smoke and dust and managed it with lots of dust collectors. About half of it was cleaned up with wet collectors, and is not relevant to woodworking. All of it however was mine to deal with. The dry collectors were called baghouses, because they contained many large filter bags. Changing these bags was umm unpleasant and expensive. It was done on overtime because nobody would do it for straight time pay. One of my assignments was to provide guidance on which collectors would be rebagged. In the finishing department castings were blasted with steel shot to remove the baked on sand. When the bags leaked the parking lot would get dusted with black sand and iron grit. On damp days this rested on and bled into the employee's cars. The plant manager got some heat over it and I was downstream between him and the maintenance department.
There were 38 collectors each about as big as a motor home, with maybe 50 bags. There was no method in place for prioritizing which collectors needed attention. Maintenance had budget constraints and traditionally was told to figure it out. The stacks to the sky were 36" in diameter and the air had a velocity of around 3000 fpm, it added up to a lot of air. I drilled two 3/8" holes in each stack to measure airflow. Interesting but not very helpful. Then I invented 'tape on a stick'. A piece of welding rod with drafting tape wrapped around it spiral fashion with the sticky part outside. Inserted in the airstream for a minute it would get coated with crap in the offending ducts. In an hour I could give Maintenance a rough guide for their efforts. In the year that I did that the savings on bag replacement probably paid my salary for life.
So will tape on a stick help to keep your shop air clean, I hope not, there are better tools and we deserve them. I really should take my own advice here.
There were 38 collectors each about as big as a motor home, with maybe 50 bags. There was no method in place for prioritizing which collectors needed attention. Maintenance had budget constraints and traditionally was told to figure it out. The stacks to the sky were 36" in diameter and the air had a velocity of around 3000 fpm, it added up to a lot of air. I drilled two 3/8" holes in each stack to measure airflow. Interesting but not very helpful. Then I invented 'tape on a stick'. A piece of welding rod with drafting tape wrapped around it spiral fashion with the sticky part outside. Inserted in the airstream for a minute it would get coated with crap in the offending ducts. In an hour I could give Maintenance a rough guide for their efforts. In the year that I did that the savings on bag replacement probably paid my salary for life.
So will tape on a stick help to keep your shop air clean, I hope not, there are better tools and we deserve them. I really should take my own advice here.