{"id":11304,"date":"2026-11-12T10:28:11","date_gmt":"2026-11-12T02:28:11","guid":{"rendered":"https:\/\/www.clirik.com\/?p=11304"},"modified":"2026-11-12T10:32:04","modified_gmt":"2026-11-12T02:32:04","slug":"air-classifying-mill-principle-how-grinding-and-classification-control-fineness","status":"publish","type":"post","link":"https:\/\/www.clirik.com\/ru\/air-classifying-mill-principle-how-grinding-and-classification-control-fineness\/","title":{"rendered":"Air Classifying Mill Principle: How Grinding and Classification Control Fineness"},"content":{"rendered":"

An air classifying mill (ACM) uses a high-speed rotor to break dry feed by impact and a rotating classifier wheel to control which particles leave. Air carries the ground material to the wheel. Finer particles tend to pass through with the air, while coarser particles tend to return to the grinding zone for another pass. The final particle size distribution depends on both how readily the feed breaks and how the classifier separates it. KONA air classifier mill study<\/a><\/p>\n\n\n\n

<\/span>How particles move through the mill<\/span><\/h2>\n\n\n\n

Feed enters the grinding zone, where rotating pins or hammers deliver the impacts that fracture it. Process air sweeps the resulting mixture of fines and coarse fragments toward the classifier wheel. Particles that pass through the wheel leave with the air. Rejected particles circulate back to the grinding zone, mix with incoming feed, and undergo further impacts. This internal loop lets fines leave after an early pass while coarse fragments receive more grinding. KONA air classifier mill study, Figure 6<\/a>
<\/p>\n\n\n\n

\"Air<\/figure>\n\n\n\n

At the classifier wheel, air flows inward between the blades and exerts drag on the particles. The rotating flow gives the particles tangential motion, creating an outward centrifugal effect. For particles of similar density and shape, finer particles follow the inward airflow more readily, while coarser particles are more likely to be rejected. The separation is gradual around the cut size. Particle density also matters, so two powders with the same measured particle size can behave differently at the same wheel speed and airflow. Experimental study of turbo air classification<\/a><\/p>\n\n\n\n

<\/span>What changes the fineness?<\/span><\/h2>\n\n\n\n

Classifier wheel speed and airflow set the separation conditions.<\/strong> At a fixed airflow, a faster wheel generally shifts the cut toward smaller particles. At a fixed wheel speed, more airflow through the wheel increases inward drag and generally shifts the cut toward larger particles. These trends have limits. In one experimental classifier, further speed increases stopped reducing the cut size and made the separation less sharp. Compare wheel speeds at the same measured airflow to see whether a speed change actually improves the product. Experimental study of turbo air classification<\/a><\/p>\n\n\n\n

Grinding rotor speed affects the impacts that create the fines.<\/strong> A tighter classifier cut sends a greater share of a given size fraction back for regrinding. The grinding zone still has to produce enough fines to sustain the required output. In a published limestone mill study, higher classifier speeds were associated with more material circulating inside the mill. When comparing settings, record the grinding rotor speed, feed rate, and collected product rate alongside the particle size results. A finer sample at lower output shows a trade-off that the size result alone would miss. KONA air classifier mill study, Table 3<\/a><\/p>\n\n\n\n

<\/span>How to check whether the product meets a size target<\/span><\/h2>\n\n\n\n

\u042d\u0442\u043e\u0442 classifier cut size<\/strong> is the particle size at which half of the material in that size class reports to the coarse stream on a pass through the classifier. The product median<\/strong>, such as Dv50 on a volume-based report, is the diameter below which 50% of the discharged sample\u2019s particle volume falls. The first describes how the wheel splits one size class. The second describes the cumulative distribution of the finished powder. Classifier separation curves<\/a> \u00b7 NIST particle size characterization guide<\/a><\/p>\n\n\n\n

For example, suppose a trial calls for a Dv90 of 45 \u00b5m or less<\/strong>. At least 90% of the measured particle volume must fall at or below 45 \u00b5m. A sample can meet its Dv50 target and still fail that Dv90 limit. To compare two settings, take representative samples after each run stabilizes and use the same measurement method and dispersion procedure. If Dv50 falls while Dv90 stays above the limit, the middle of the distribution has shifted finer, but the coarse end still fails the specification. NIST particle size characterization guide<\/a><\/p>","protected":false},"excerpt":{"rendered":"

An air classifying mill (ACM) uses a high-speed rotor to break dry feed by impact and a rotating classifier wheel to control which particles leave. Air carries the ground material to the wheel. Finer particles tend to pass through with the air, while coarser particles tend to return to the grinding zone for another pass. […]<\/p>","protected":false},"author":16,"featured_media":11305,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"themepark_post_bcolor":"#f5f5f5","themepark_post_width":"1022px","themepark_post_img":"","themepark_post_img_po":"left","themepark_post_img_re":false,"themepark_post_img_cover":false,"themepark_post_img_fixed":false,"themepark_post_hide_title":false,"themepark_post_main_b":"","themepark_post_main_p":100,"themepark_paddingblock":false,"_geo_short_summary":"","_geo_structured_desc":"","_geo_faqs":"","_geo_key_points":"","_geo_target_audience":"","_geo_content_type":"","_geo_last_modified":"","_geo_version":0,"themepark_seo_title":"Air Classifying Mill Principle and Particle Size Control","themepark_seo_description":"An Air Classifying Mill Grinds By Impact, Carries Fines Out In Air, And Returns Coarse Particles For Regrinding. See How Wheel Speed Affects The Cut Size.","footnotes":""},"categories":[11],"tags":[],"class_list":["post-11304","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news-article"],"metadata":{"_edit_lock":["1794450727:16"],"rank_math_primary_category":["11"],"rank_math_seo_score":["13"],"views":["32"],"_thumbnail_id":["11305"],"_edit_last":["16"],"_ez-toc-disabled":[""],"_ez-toc-insert":[""],"_ez-toc-header-label":[""],"_ez-toc-device-target":[""],"_ez-toc-alignment":["none"],"_ez-toc-heading-levels":["a:0:{}"],"_ez-toc-alttext":[""],"_ez-toc-visibility_hide_by_default":[""],"_ez-toc-hide_counter":[""],"_ez-toc-exclude":[""],"_ez-toc-word_count_limit":["0"],"_ez-toc-position-specific":[""],"catce":["sidebar-widgets4"],"_wp_page_template":["default"],"themepark_seo_title":["Air Classifying Mill Principle and Particle Size Control"],"themepark_seo_description":["An Air Classifying Mill Grinds By Impact, Carries Fines Out In Air, And Returns Coarse Particles For Regrinding. See How Wheel Speed Affects The Cut Size."],"themepark_seo_keyword":["Air Classifying Mill Principle"]},"views":32,"medium_url":"https:\/\/www.clirik.com\/wp-content\/uploads\/2026\/11\/pasted-image-20261112-022711-992.png","thumbnail_url":"https:\/\/www.clirik.com\/wp-content\/uploads\/2026\/11\/pasted-image-20261112-022710-911.png","full_url":"https:\/\/www.clirik.com\/wp-content\/uploads\/2026\/11\/pasted-image-20261112-022701-170.png","_links":{"self":[{"href":"https:\/\/www.clirik.com\/ru\/wp-json\/wp\/v2\/posts\/11304","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.clirik.com\/ru\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.clirik.com\/ru\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.clirik.com\/ru\/wp-json\/wp\/v2\/users\/16"}],"replies":[{"embeddable":true,"href":"https:\/\/www.clirik.com\/ru\/wp-json\/wp\/v2\/comments?post=11304"}],"version-history":[{"count":1,"href":"https:\/\/www.clirik.com\/ru\/wp-json\/wp\/v2\/posts\/11304\/revisions"}],"predecessor-version":[{"id":11306,"href":"https:\/\/www.clirik.com\/ru\/wp-json\/wp\/v2\/posts\/11304\/revisions\/11306"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.clirik.com\/ru\/wp-json\/wp\/v2\/media\/11305"}],"wp:attachment":[{"href":"https:\/\/www.clirik.com\/ru\/wp-json\/wp\/v2\/media?parent=11304"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.clirik.com\/ru\/wp-json\/wp\/v2\/categories?post=11304"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.clirik.com\/ru\/wp-json\/wp\/v2\/tags?post=11304"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}