{"id":190,"date":"2009-11-04T15:59:40","date_gmt":"2009-11-04T22:59:40","guid":{"rendered":"http:\/\/www.dcddesign.com\/blog\/?p=190"},"modified":"2009-11-04T15:59:40","modified_gmt":"2009-11-04T22:59:40","slug":"understanding-blower-performance","status":"publish","type":"post","link":"https:\/\/www.dcddesign.com\/blog\/understanding-blower-performance\/","title":{"rendered":"Understanding Blower Performance"},"content":{"rendered":"

Here’s a quick explanation of flow rate versus pressure. When you need to go farther, make sure you’re comparing the right numbers!
\nThe output of a blower is usually specified in terms of (i) its flow rate (cfm), and (ii) its pressure (psi). The flow rate determines how fast the blower can move a projectile, and the pressure determines how much and how far the projectile can pull a load. (Compare it with RPM vs. Torque.)
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\nWhen a blower is running with an unrestricted outlet, it will produce its maximum specified flow rate because there is no resistance against it. (The RPM’s go to red-line.)
\nIf the blower is attached to a length of empty conduit, the blower has to move all the air in the conduit to push any through. Friction against the conduit wall will resist that movement. As the blower works against this backpressure, its flow rate drops. (Pop the clutch and engage the drivetrain, the RPM’s drop.)
\nTherefore \u2026 a blower can never produce its maximum specified flow rate in a practical application due to air friction in the duct.
\nAs the length of conduit increases, friction increases, backpressure increases, and flow rate decreases. At some point, the backpressure will increase to a point at which it equals the maximum pressure that the blower can generate, and the flow rate will be zero. (Drop the RPM’s against Torque, and the engine will stall.)
\nWhen a projectile is inserted, it blocks the conduit. As more air is pushed in behind the projectile, the backpressure rises until it exceeds the projectile’s drag and it begins to move along the conduit. Therefore \u2026 the drag creates the backpressure which, in turn, determines the blower flow rate and ultimately the speed of the projectile. (Keep your foot down, and the RPM’s up, and you’ll overcome Torque and accelerate.)
\nAs the projectile moves down the conduit, the drag force increases because of the weight and friction of the line being pulled is increasing. At some distance, the increasing backpressure equals the maximum pressure that the blower can develop, and the projectile will stall. (Think tractor pulls: the towing load is always increasing; RPM’s are limited; sooner or later, the tractor gets stuck.)
\nBecause only blowing pressure can overcome backpressure, a blower with higher blowing pressure capability will ultimately go farther. The DCD Power Blower<\/a> was designed around twin, high-pressure motors to go farther. Compare the data when you have a line-blowing job. More pressure, more distance.
\n\"\"<\/p>\n","protected":false},"excerpt":{"rendered":"

Here’s a quick explanation of flow rate versus pressure. When you need to go farther, make sure you’re comparing the right numbers! The output of a blower is usually specified […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[55,41],"tags":[94,23,95,96],"class_list":["post-190","post","type-post","status-publish","format-standard","hentry","category-cable-installation","category-how-to","tag-blower","tag-line-blowing","tag-power-blower","tag-pull-tape"],"_links":{"self":[{"href":"https:\/\/www.dcddesign.com\/blog\/wp-json\/wp\/v2\/posts\/190","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.dcddesign.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.dcddesign.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.dcddesign.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.dcddesign.com\/blog\/wp-json\/wp\/v2\/comments?post=190"}],"version-history":[{"count":0,"href":"https:\/\/www.dcddesign.com\/blog\/wp-json\/wp\/v2\/posts\/190\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.dcddesign.com\/blog\/wp-json\/wp\/v2\/media?parent=190"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.dcddesign.com\/blog\/wp-json\/wp\/v2\/categories?post=190"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.dcddesign.com\/blog\/wp-json\/wp\/v2\/tags?post=190"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}