{"id":215,"date":"2024-06-27T09:44:30","date_gmt":"2024-06-27T09:44:30","guid":{"rendered":"https:\/\/study.madeeasy.in\/?p=215"},"modified":"2025-07-16T14:41:43","modified_gmt":"2025-07-16T09:11:43","slug":"what-is-rotary-compressors-and-its-types","status":"publish","type":"post","link":"https:\/\/www.madeeasy.in\/study\/me\/power-plant\/what-is-rotary-compressors-and-its-types","title":{"rendered":"What is Rotary Compressors and Its Types?"},"content":{"rendered":"\r\n<p style=\"text-align: justify;\">Rotary compressors are used to supply continuous pulsation free compressed air. They have rotors and casing in place of piston cylinder arrangement. Rotary compressors are compact well balanced, and high speed compressors. Due to low starting torque they can be directly coupled with prime-mover. They handle large mass of gas and are suitable for low and medium pressure ratios.<\/p>\r\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-119 aligncenter\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/rotary-compressors.jpg\" alt=\"Rotary Compressors\" width=\"315\" height=\"153\" \/><\/p>\r\n<ul style=\"text-align: justify;\">\r\n<li>Rotary compressors are the <strong>steady flow compressors<\/strong> and examples are <strong>centrifugal compressor<\/strong> and axial <strong>flow compressor<\/strong>.<\/li>\r\n<li>In steady flow compressor &#x27a1;&#xfe0f; Compression occurs by transfer of KE from the rotor.<\/li>\r\n<\/ul>\r\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-120 aligncenter\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/velocity.jpg\" alt=\"Velocity\" width=\"281\" height=\"235\" \/><\/p>\r\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_79_1 ez-toc-wrap-left counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.madeeasy.in\/study\/me\/power-plant\/what-is-rotary-compressors-and-its-types\/#Working-of-Centrifugal-Compressor\" >Working of Centrifugal Compressor<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.madeeasy.in\/study\/me\/power-plant\/what-is-rotary-compressors-and-its-types\/#Dimensionless-Parameter-of-Centrifugal-Compressor\" >Dimensionless Parameter of Centrifugal Compressor<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.madeeasy.in\/study\/me\/power-plant\/what-is-rotary-compressors-and-its-types\/#Losses-in-Centrifugal-Compressor\" >Losses in Centrifugal Compressor<\/a><\/li><\/ul><\/nav><\/div>\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"Working-of-Centrifugal-Compressor\"><\/span>Working of Centrifugal Compressor<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<ul style=\"text-align: justify;\">\r\n<li>Air enters the eye of impeller with low velocity <em>V<\/em><sub>1<\/sub> and atmospheric pressure <em>p<\/em><sub>1<\/sub>.<br \/>Impeller transfers the energy of drive to the air, due to which static pressure, temperature and velocity increases. Let the increased pressure and velocity be <em>p<\/em><sub>2<\/sub> and <em>V<\/em><sub>2<\/sub> respectively.<br \/>Work input in impeller = Rise in total temperature<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify;\">\r\n<li>Now air enters into diffuser (diverging section) where velocity decreases to <em>V<\/em><sub>3<\/sub>.<br \/>K.E. is converted into pressure energy which causes further rise in static pressure <em>p<\/em><sub>3<\/sub> as shown in figure.<\/li>\r\n<\/ul>\r\n<ul style=\"text-align: justify;\">\r\n<li>Pressure energy achieved in impeller = Pressure energy achieved in diffuser<br \/>With single-stage centrifugal compressor, pressure ratio of 5 : 1 can be achieved<br \/>And with multi-stage centrifugal compressor, a pressure ratio of 12 : 1 can be attained.<\/li>\r\n<\/ul>\r\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"Dimensionless-Parameter-of-Centrifugal-Compressor\"><\/span>Dimensionless Parameter of Centrifugal Compressor<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<h5 style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-127\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/slip-factor.jpg\" alt=\"Slip Factor\" width=\"172\" height=\"28\" \/><\/h5>\r\n<p style=\"text-align: justify;\">The energy transfer occurring in the impeller corresponding to real velocity profile is less than the one that would have been obtained with one dimensional flow, the apex of the actual velocity triangle at the impeller exit is shifted away (opposite to the direction of rotation) from the apex of the ideal velocity triangle. This phenomenon is known as slip and the shift of the apex is the slip velocity (<em>V<\/em><em>s<\/em>).<\/p>\r\n<p style=\"text-align: justify;\">Slip = <em>u<\/em><sub>2<\/sub> &#8211;<em>V<sub>w<\/sub><\/em>2<\/p>\r\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-124 size-full aligncenter\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/centrifugal-compressor-1.jpg\" alt=\"Centrifugal Compressor\" width=\"636\" height=\"416\" \/><\/p>\r\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-129\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/power-input.jpg\" alt=\"Power Input\" width=\"690\" height=\"282\" \/><\/p>\r\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-131\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/flow-coefficient.png\" alt=\"Flow Coefficient\" width=\"622\" height=\"224\" \/><\/p>\r\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-134\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/head-coefficient.jpg\" alt=\"Head Coefficient\" width=\"730\" height=\"438\" \/><\/p>\r\n<h3 style=\"text-align: justify;\"><span class=\"ez-toc-section\" id=\"Losses-in-Centrifugal-Compressor\"><\/span>Losses in Centrifugal Compressor<span class=\"ez-toc-section-end\"><\/span><\/h3>\r\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-135\" src=\"http:\/\/study.madeeasy.in\/wp-content\/uploads\/2024\/06\/frictional-losses.jpg\" alt=\"Frictional Losses\" width=\"653\" height=\"334\" \/><\/p>\r\n<p style=\"text-align: justify;\">If the losses are subtracted from the ideal energy transfer for a radial vaned impeller, then the constant pressure ratio straight line characteristics becomes curved, with a maximum value of energy at some particular value of mass flow rate.<\/p>\r\n<p style=\"text-align: justify;\">\u00a0<\/p>\r\n\r\n\r\n\r\n<p class=\"wp-block-paragraph\">&nbsp;<\/p>\r\n\r\n\r\n\r\n<p style=\"text-align: center;\"><a class=\"btn btn-danger\" role=\"button\" href=\"https:\/\/study.madeeasy.in\/me\/power-plant\/actual-p-v-diagram-for-single-stage-compressor\/\" target=\"_blank\" rel=\"noopener\">&lt;&lt; Previous<\/a> | <a class=\"btn btn-success\" role=\"button\" href=\"https:\/\/study.madeeasy.in\/me\/power-plant\/what-is-axial-flow-compressor\/\" target=\"_blank\" rel=\"noopener\"> Next &gt;&gt;<\/a> <br \/><strong> Must Read: <\/strong> <a href=\"https:\/\/study.madeeasy.in\/subjects\/what-is-power-plant-engineering\/\" target=\"_blank\" rel=\"noopener\"><strong>What is Power Plant Engineering?<\/strong><\/a><\/p>\r\n<p>&nbsp;<\/p>\r\n","protected":false},"excerpt":{"rendered":"<p>Rotary compressors are used to supply continuous pulsation free compressed air. They have rotors and casing in place of piston<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[55,10],"tags":[70,69,72,71],"class_list":["post-215","post","type-post","status-publish","format-standard","hentry","category-power-plant","category-me","tag-5-types-of-compressors","tag-rotary-compressor-diagram","tag-rotary-screw-air-compressors","tag-what-is-rotary-compressor"],"_links":{"self":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts\/215","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/comments?post=215"}],"version-history":[{"count":0,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/posts\/215\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/media?parent=215"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/categories?post=215"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.madeeasy.in\/study\/wp-json\/wp\/v2\/tags?post=215"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}