{"id":48917,"date":"2019-11-13T19:05:52","date_gmt":"2019-11-13T18:05:52","guid":{"rendered":"https:\/\/www.thermal-engineering.org\/o-que-e-cavitacao-em-bombas-centrifugas-definicao\/"},"modified":"2020-02-01T09:22:14","modified_gmt":"2020-02-01T08:22:14","slug":"o-que-e-cavitacao-em-bombas-centrifugas-definicao","status":"publish","type":"post","link":"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-cavitacao-em-bombas-centrifugas-definicao\/","title":{"rendered":"O que \u00e9 cavita\u00e7\u00e3o em bombas centr\u00edfugas &#8211; defini\u00e7\u00e3o"},"content":{"rendered":"<div class=\"su-quote su-quote-style-default\">\n<div class=\"su-quote-inner su-clearfix\">Cavita\u00e7\u00e3o \u00e9 uma ocorr\u00eancia indesej\u00e1vel. Nas bombas centr\u00edfugas, a cavita\u00e7\u00e3o causa danos aos componentes (eros\u00e3o do material), vibra\u00e7\u00f5es, ru\u00eddos e perda de efici\u00eancia. Engenharia T\u00e9rmica<\/div>\n<\/div>\n<div><\/div>\n<div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<h2><span>Cavita\u00e7\u00e3o em Bombas Centr\u00edfugas<\/span><\/h2>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/cavitation-damaged-impeller-min.png\"><img loading=\"lazy\" class=\"alignright  wp-image-15096 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/cavitation-damaged-impeller-min-300x229.png\" alt=\"cavita\u00e7\u00e3o - impulsor danificado-min\" width=\"187\" height=\"143\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/cavitation-damaged-impeller-min-300x229.png\" \/><\/a><span>Principais locais onde\u00a0<\/span><strong><span>a cavita\u00e7\u00e3o<\/span><\/strong><span>\u00a0ocorre s\u00e3o em bombas,\u00a0<\/span><strong><span>em\u00a0<\/span><a title=\"Impulsor - Tipos de impulsores\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/centrifugal-pumps\/impeller-types-of-impellers\/\"><span>turbinas<\/span><\/a><span>\u00a0ou h\u00e9lices<\/span><\/strong><span>\u00a0.\u00a0Nas bombas centr\u00edfugas, a cavita\u00e7\u00e3o resulta de uma\u00a0<\/span><strong><span>redu\u00e7\u00e3o na press\u00e3o de suc\u00e7\u00e3o<\/span><\/strong><span>\u00a0, um\u00a0<\/span><strong><span>aumento na temperatura de suc\u00e7\u00e3o<\/span><\/strong><span>\u00a0ou um\u00a0<\/span><strong><span>aumento na vaz\u00e3o<\/span><\/strong><span>\u00a0acima daquela para a qual a bomba foi projetada.<\/span><\/p>\n<p><span>Existem dois\u00a0<\/span><strong><span>tipos<\/span><\/strong><span>\u00a0b\u00e1sicos\u00a0<strong>de cavita\u00e7\u00e3o da bomba<\/strong>\u00a0:<\/span><\/p>\n<div class=\"su-spacer\"><\/div>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<h2><span>Cavita\u00e7\u00e3o por suc\u00e7\u00e3o<\/span><\/h2>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/suction-cavitation-impeller-min.png\"><img loading=\"lazy\" class=\"alignright  wp-image-15095 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/suction-cavitation-impeller-min.png\" alt=\"cavita\u00e7\u00e3o de suc\u00e7\u00e3o - impulsor-min\" width=\"364\" height=\"300\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/suction-cavitation-impeller-min.png\" \/><\/a><strong><span>A cavita\u00e7\u00e3o por suc\u00e7\u00e3o<\/span><\/strong><span>\u00a0, ou tamb\u00e9m a\u00a0<\/span><strong><span>cavita\u00e7\u00e3o cl\u00e1ssica<\/span><\/strong><span>\u00a0, ocorre quando uma bomba est\u00e1 sob\u00a0<\/span><strong><span>baixa press\u00e3o<\/span><\/strong><span>\u00a0ou condi\u00e7\u00f5es de alto v\u00e1cuo.\u00a0Quando o l\u00edquido sendo bombeado entra no olho de uma\u00a0<\/span><a title=\"Bombas centr\u00edfugas\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-bomba-centrifuga-definicao\/\"><span>bomba centr\u00edfuga<\/span><\/a><span>\u00a0,\u00a0<\/span><strong><span>a press\u00e3o \u00e9 significativamente reduzida<\/span><\/strong><span>\u00a0.\u00a0Em alguns casos, a queda de press\u00e3o \u00e9 grande o suficiente para fazer com que o l\u00edquido pisque ao vapor quando a\u00a0<\/span><strong><span>press\u00e3o local cai<\/span><\/strong><span>\u00a0abaixo da\u00a0<\/span><strong><span>press\u00e3o de satura\u00e7\u00e3o<\/span><\/strong><span>\u00a0do fluido que est\u00e1 sendo bombeado.\u00a0<\/span><strong><span>Bolhas ou cavidades<\/span><\/strong><span>\u00a0se formar\u00e3o no olho do impulsor e, subsequentemente, as bolhas de vapor formadas se mover\u00e3o para\u00a0<\/span><strong><span>regi\u00f5es de press\u00e3o mais alta \u00e0<\/span><\/strong><span>\u00a0medida que viajam em dire\u00e7\u00e3o \u00e0 descarga da bomba.\u00a0Na regi\u00e3o de maior press\u00e3o, a<\/span><strong><span>bolhas de vapor colapsam repentinamente<\/span><\/strong><span>\u00a0nas partes externas do impulsor.\u00a0Isso pode causar danos significativos a todas as partes m\u00f3veis de uma bomba centr\u00edfuga.<\/span><\/p>\n<p><strong><span>Causas t\u00edpicas da cavita\u00e7\u00e3o por suc\u00e7\u00e3o:<\/span><\/strong><\/p>\n<ul>\n<li><span>A bomba est\u00e1 funcionando muito longe na\u00a0<\/span><a title=\"Cabe\u00e7a da bomba - curva de desempenho da bomba centr\u00edfuga\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/centrifugal-pumps\/pump-head-performance-curve\/\"><span>curva da bomba<\/span><\/a><\/li>\n<li><span>M\u00e1s condi\u00e7\u00f5es de suc\u00e7\u00e3o (\u00a0<\/span><a title=\"Cabe\u00e7a de suc\u00e7\u00e3o positiva l\u00edquida\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/centrifugal-pumps\/net-positive-suction-head\/\"><span>requisitos NPSH<\/span><\/a><span>\u00a0)<\/span><\/li>\n<li><span>Bloqueio no tubo no lado de suc\u00e7\u00e3o<\/span><\/li>\n<li><span>Projeto de tubula\u00e7\u00e3o inadequado<\/span><\/li>\n<li><span>Filtros ou filtros entupidos<\/span><\/li>\n<\/ul>\n<p><span>Para evitar esse tipo de cavita\u00e7\u00e3o, a\u00a0<\/span><strong><span>Cabe\u00e7a de Suc\u00e7\u00e3o Positiva L\u00edquida dispon\u00edvel (NPSHa)<\/span><\/strong><span>\u00a0no sistema deve ser\u00a0<\/span><strong><span>maior que<\/span><\/strong><span>\u00a0o\u00a0<\/span><strong><span>NPSH necess\u00e1rio<\/span><\/strong><span>\u00a0da bomba.\u00a0Esse problema \u00e9 t\u00edpico da cavita\u00e7\u00e3o por suc\u00e7\u00e3o e, portanto, esse tipo de cavita\u00e7\u00e3o tamb\u00e9m \u00e9 chamado de\u00a0<\/span><strong><span>cavita\u00e7\u00e3o NPSHa inadequada<\/span><\/strong><span>\u00a0.<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Net-Positive-Suction-Head-chart.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-15002 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Net-Positive-Suction-Head-chart.png\" alt=\"Cabe\u00e7a de suc\u00e7\u00e3o positiva l\u00edquida\" width=\"654\" height=\"356\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/Net-Positive-Suction-Head-chart.png\" \/><\/a><\/p>\n<p><span>Al\u00e9m da troca da bomba, os problemas com a cavita\u00e7\u00e3o por suc\u00e7\u00e3o tamb\u00e9m podem ser resolvidos por:<\/span><\/p>\n<ol>\n<li><span>Baixando a temperatura<\/span><\/li>\n<li><span>Redu\u00e7\u00e3o da rota\u00e7\u00e3o do motor, se poss\u00edvel<\/span><\/li>\n<li><span>Aumento do di\u00e2metro do olho do impulsor<\/span><\/li>\n<li><span>Uso de um indutor de impulsor.<\/span><\/li>\n<li><span>Uso de duas bombas paralelas com menor capacidade.<\/span><\/li>\n<li><span>Uso de uma bomba auxiliar para alimentar a bomba principal.<\/span><\/li>\n<\/ol>\n<p><span>Caso especial de cavita\u00e7\u00e3o ocorre no lado da suc\u00e7\u00e3o como resultado de tubula\u00e7\u00e3o inadequada na linha de suc\u00e7\u00e3o.\u00a0O uso de restri\u00e7\u00f5es,\u00a0<\/span><a title=\"Fluxo atrav\u00e9s do cotovelo - perda menor\" href=\"https:\/\/www.nuclear-power.com\/nuclear-engineering\/fluid-dynamics\/minor-head-loss-local-losses\/flow-through-elbow-minor-loss-2\/\"><span>cotovelos<\/span><\/a><span>\u00a0afiados\u00a0e outros equipamentos hidr\u00e1ulicos podem\u00a0<\/span><a title=\"Fluxo turbulento\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-fluxo-turbulento-definicao\/\"><strong><span>turbulizar o fluxo,<\/span><\/strong><\/a><span> o que pode contribuir para a forma\u00e7\u00e3o de cavita\u00e7\u00e3o.<\/span><\/p>\n<p>&nbsp;<\/p>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<h2><span>Cavita\u00e7\u00e3o de descarga<\/span><\/h2>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/discharge-cavitation-pump-min.png\"><img loading=\"lazy\" class=\"alignright size-full wp-image-15094 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/discharge-cavitation-pump-min.png\" alt=\"cavita\u00e7\u00e3o de descarga - bomba-min\" width=\"298\" height=\"321\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/discharge-cavitation-pump-min.png\" \/><\/a><strong><span>A cavita\u00e7\u00e3o da descarga<\/span><\/strong><span>\u00a0ocorre quando a\u00a0<\/span><strong><span>press\u00e3o de descarga<\/span><\/strong><span>\u00a0da bomba\u00a0\u00e9\u00a0<\/span><strong><span>extremamente alta<\/span><\/strong><span>\u00a0ou quando o fluxo de descarga \u00e9 restrito e n\u00e3o pode sair da bomba (por exemplo, causada por uma v\u00e1lvula de sa\u00edda fechada).\u00a0Uma press\u00e3o de descarga extremamente alta resulta na maioria do fluido bombeado\u00a0<\/span><strong><span>circulando dentro da bomba<\/span><\/strong><span>\u00a0.<\/span><\/p>\n<p><span>Este tipo de cavita\u00e7\u00e3o se origina de duas fontes.\u00a0Primeiro, essa\u00a0<\/span><strong><span>circula\u00e7\u00e3o interna<\/span><\/strong><span>\u00a0(das zonas de alta press\u00e3o para as zonas de baixa press\u00e3o) \u00e9 for\u00e7ada atrav\u00e9s da folga entre o impulsor e o compartimento da bomba em\u00a0<\/span><strong><span>alta velocidade,<\/span><\/strong><span>\u00a0resultando na forma\u00e7\u00e3o de uma\u00a0<\/span><strong><span>regi\u00e3o de baixa press\u00e3o<\/span><\/strong><span>\u00a0(como resultado\u00a0<\/span><a title=\"Equa\u00e7\u00e3o de Bernoulli - Princ\u00edpio de Bernoulli\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-a-equacao-de-bernoulli-principio-de-bernoulli-definicao\/\"><span>do princ\u00edpio<\/span><\/a><span>\u00a0de\u00a0<a title=\"Equa\u00e7\u00e3o de Bernoulli - Princ\u00edpio de Bernoulli\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-a-equacao-de-bernoulli-principio-de-bernoulli-definicao\/\">Bernoulli<\/a>\u00a0). qual cavita\u00e7\u00e3o pode ocorrer.\u00a0Segundo, o l\u00edquido est\u00e1 circulando dentro da voluta da bomba e superaquece rapidamente.<\/span><\/p>\n<p><span>Nos dois casos, a cavita\u00e7\u00e3o tem consequ\u00eancias semelhantes.\u00a0A implos\u00e3o de bolhas desencadeia ondas de choque intensas, causando desgaste prematuro das pontas do impulsor e da carca\u00e7a da bomba.\u00a0Em casos extremos, a cavita\u00e7\u00e3o de descarga pode causar a quebra do eixo do impulsor.<\/span><\/p>\n<p><strong><span>Causas t\u00edpicas da cavita\u00e7\u00e3o de descarga:<\/span><\/strong><\/p>\n<ul>\n<li><span>A bomba est\u00e1 funcionando muito \u00e0 esquerda na curva da bomba<\/span><\/li>\n<li><span>Bloqueio no tubo no lado da descarga<\/span><\/li>\n<li><span>Filtros ou filtros entupidos<\/span><\/li>\n<li><span>Projeto de tubula\u00e7\u00e3o inadequado<\/span><\/li>\n<\/ul>\n<div class=\"su-spacer\"><\/div>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<h2><span>N\u00famero de cavita\u00e7\u00e3o<\/span><\/h2>\n<p><span>O\u00a0<\/span><strong><span>n\u00famero de cavita\u00e7\u00e3o (Ca)<\/span><\/strong><span>\u00a0ou o\u00a0<\/span><strong><span>par\u00e2metro de cavita\u00e7\u00e3o<\/span><\/strong><span>\u00a0\u00e9 um n\u00famero sem dimens\u00e3o usado nos c\u00e1lculos de fluxo.\u00a0\u00c9 convencional caracterizar a proximidade da press\u00e3o no fluxo do l\u00edquido com a press\u00e3o do vapor (e, portanto, o potencial de cavita\u00e7\u00e3o) por meio do n\u00famero da cavita\u00e7\u00e3o.<\/span><\/p>\n<p><span>O n\u00famero da cavita\u00e7\u00e3o pode ser expresso como:<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/cavitation-number-equation.png\"><img loading=\"lazy\" class=\"aligncenter size-full wp-image-15097 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/cavitation-number-equation.png\" alt=\"n\u00famero de cavita\u00e7\u00e3o - equa\u00e7\u00e3o\" width=\"157\" height=\"86\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/cavitation-number-equation.png\" \/><\/a><\/p>\n<p><span>Onde<\/span><\/p>\n<p><em><span>CA = n\u00famero de cavita\u00e7\u00e3o<\/span><\/em><\/p>\n<p><em><span>p = press\u00e3o local (Pa)<\/span><\/em><\/p>\n<p><em><span>p\u00a0<\/span><\/em><em><sub><span>v<\/span><\/sub><\/em><em><span>\u00a0= press\u00e3o de vapor do fluido (Pa)<\/span><\/em><\/p>\n<p><em><span>\u03c1 = densidade do fluido (kg \/ m\u00a0<\/span><\/em><em><sup><span>3<\/span><\/sup><\/em><em><span>\u00a0)<\/span><\/em><\/p>\n<p><em><span>v = velocidade do fluido (m \/ s)<\/span><\/em><\/p>\n<div class=\"su-spacer\"><\/div>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights  lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-spacer\"><\/div>\n<h2><span>Danos por cavita\u00e7\u00e3o<\/span><\/h2>\n<p><strong><span>A cavita\u00e7\u00e3o<\/span><\/strong><span>\u00a0\u00e9, em muitos casos, uma ocorr\u00eancia indesej\u00e1vel.\u00a0Nas bombas centr\u00edfugas, a cavita\u00e7\u00e3o causa\u00a0<\/span><strong><span>danos aos componentes<\/span><\/strong><span>\u00a0(eros\u00e3o do material), vibra\u00e7\u00f5es, ru\u00eddos e perda de efici\u00eancia.<\/span><\/p>\n<figure id=\"attachment_15093\" class=\"wp-caption alignright\" aria-describedby=\"caption-attachment-15093\"><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/cavitation-damage-min.png\"><img loading=\"lazy\" class=\"size-medium wp-image-15093 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/cavitation-damage-min-300x178.png\" alt=\"Fonte: Wikipedia, CC BY 2.5, https:\/\/commons.wikimedia.org\/wiki\/File:Turbine_Francis_Worn.JPG\" width=\"300\" height=\"178\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/cavitation-damage-min-300x178.png\" \/><\/a><figcaption id=\"caption-attachment-15093\" class=\"wp-caption-text\"><span>Fonte: Wikipedia, CC BY 2.5,<\/span><br \/>\n<span>https:\/\/commons.wikimedia.org\/wiki\/File:Turbine_Francis_Worn.JPG<\/span><\/figcaption><\/figure>\n<p><span>Talvez o problema de engenharia mais importante causado pela cavita\u00e7\u00e3o seja o\u00a0<\/span><strong><span>dano material<\/span><\/strong><span>\u00a0que as bolhas de cavita\u00e7\u00e3o podem causar quando\u00a0<\/span><strong><span>colapsam<\/span><\/strong><span>\u00a0nas proximidades de uma superf\u00edcie s\u00f3lida.\u00a0O colapso das bolhas de cavita\u00e7\u00e3o \u00e9 um processo violento que gera\u00a0<\/span><strong><span>ondas de choque<\/span><\/strong><span>\u00a0e\u00a0<\/span><strong><span>microjatos\u00a0<\/span><\/strong><span><strong>altamente localizados<\/strong>\u00a0.\u00a0Eles for\u00e7am o l\u00edquido energ\u00e9tico em volumes muito pequenos, criando pontos de alta temperatura e esses dist\u00farbios intensos geram tens\u00f5es superficiais transit\u00f3rias e altamente localizadas em uma superf\u00edcie s\u00f3lida.\u00a0Os sinais de\u00a0<\/span><strong><span>eros\u00e3o<\/span><\/strong><span>\u00a0aparecer\u00e3o como\u00a0<\/span><strong><span>pontinhos<\/span><\/strong><span>\u00a0devido \u00e0 a\u00e7\u00e3o de golpe de \u00e1gua das bolhas de vapor em colapso.\u00a0Verificou-se que as taxas de danos por cavita\u00e7\u00e3o\u00a0<\/span><strong><span>aumentam rapidamente<\/span><\/strong><span>\u00a0com o aumento da vaz\u00e3o do volume.<\/span><\/p>\n<p><strong><span>Materiais mais macios<\/span><\/strong><span>\u00a0podem ser danificados mesmo pela\u00a0ocorr\u00eancia de\u00a0<strong>cavita\u00e7\u00e3o a\u00a0<\/strong><\/span><strong><span>curto prazo<\/span><\/strong><span>\u00a0.\u00a0Pontua\u00e7\u00f5es individuais podem ser observadas ap\u00f3s um \u00fanico colapso da bolha.\u00a0Portanto, materiais mais duros s\u00e3o usados \u200b\u200bpara\u00a0<strong>bombas centr\u00edfugas<\/strong>\u00a0.\u00a0Por\u00e9m, com os materiais mais duros usados \u200b\u200bna maioria das aplica\u00e7\u00f5es, o\u00a0<strong>estresse c\u00edclico<\/strong>\u00a0devido a colapsos repetidos pode causar\u00a0<strong>falha na fadiga da superf\u00edcie local<\/strong>\u00a0.\u00a0Assim, os danos causados \u200b\u200bpela cavita\u00e7\u00e3o aos metais geralmente t\u00eam a apar\u00eancia de\u00a0<strong>falha por fadiga<\/strong>\u00a0.<\/span><\/p>\n<p><a href=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/cavitation-bubble-collapse-min.png\"><img loading=\"lazy\" class=\"alignright size-medium wp-image-15092 lazy-loaded\" src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/cavitation-bubble-collapse-min-300x154.png\" alt=\"cavita\u00e7\u00e3o - bolha em colapso-min\" width=\"300\" height=\"154\" data-lazy-type=\"image\" data-src=\"https:\/\/thermal-engineering.org\/wp-content\/uploads\/2019\/05\/cavitation-bubble-collapse-min-300x154.png\" \/><\/a><span>Quando as bolhas de cavita\u00e7\u00e3o colapsam, elas for\u00e7am o l\u00edquido energ\u00e9tico a volumes muito pequenos, criando pontos de alta temperatura e emitindo ondas de choque, as quais s\u00e3o uma fonte de ru\u00eddo.\u00a0Embora o colapso de uma pequena cavidade seja um evento de energia relativamente baixa, colapsos altamente localizados podem corroer metais, como o a\u00e7o, ao longo do tempo.\u00a0A picada causada pelo colapso das cavidades produz um grande desgaste dos componentes e pode reduzir drasticamente a vida \u00fatil da h\u00e9lice ou da bomba.<\/span><\/p>\n<p><span>A cavita\u00e7\u00e3o \u00e9 geralmente acompanhada tamb\u00e9m por:<\/span><\/p>\n<ul>\n<li><strong><span>Ru\u00eddo.\u00a0<\/span><\/strong><span>O ru\u00eddo t\u00edpico \u00e9 causado por cavidades em colapso.\u00a0O n\u00edvel do ru\u00eddo resultante da cavita\u00e7\u00e3o \u00e9 uma medida da gravidade da cavita\u00e7\u00e3o.<\/span><\/li>\n<li><strong><span>Vibra\u00e7\u00e3o<\/span><\/strong><span>\u00a0.\u00a0As vibra\u00e7\u00f5es da bomba devido \u00e0 cavita\u00e7\u00e3o s\u00e3o caracteristicamente baixas vibra\u00e7\u00f5es de frequ\u00eancia, geralmente encontradas na faixa de 0 a 10 Hz.<\/span><\/li>\n<li><strong><span>Redu\u00e7\u00e3o na efici\u00eancia da bomba<\/span><\/strong><span>\u00a0.\u00a0Uma diminui\u00e7\u00e3o na efici\u00eancia da bomba \u00e9 um sinal mais confi\u00e1vel de cavita\u00e7\u00e3o.<\/span><\/li>\n<\/ul>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"lgc-column lgc-grid-parent lgc-grid-100 lgc-tablet-grid-100 lgc-mobile-grid-100 lgc-equal-heights lgc-first lgc-last\">\n<div class=\"inside-grid-column\">\n<div class=\"su-accordion\">\n<p>&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;&#8230;.<\/p>\n<p>Este artigo \u00e9 baseado na tradu\u00e7\u00e3o autom\u00e1tica do artigo original em ingl\u00eas. Para mais informa\u00e7\u00f5es, consulte o artigo em ingl\u00eas. Voc\u00ea pode nos ajudar. Se voc\u00ea deseja corrigir a tradu\u00e7\u00e3o, envie-a para: translations@nuclear-power.com ou preencha o formul\u00e1rio de tradu\u00e7\u00e3o on-line. Agradecemos sua ajuda, atualizaremos a tradu\u00e7\u00e3o o mais r\u00e1pido poss\u00edvel. Obrigado.<\/p>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Cavita\u00e7\u00e3o \u00e9 uma ocorr\u00eancia indesej\u00e1vel. Nas bombas centr\u00edfugas, a cavita\u00e7\u00e3o causa danos aos componentes (eros\u00e3o do material), vibra\u00e7\u00f5es, ru\u00eddos e perda de efici\u00eancia. Engenharia T\u00e9rmica Cavita\u00e7\u00e3o em Bombas Centr\u00edfugas Principais locais onde\u00a0a cavita\u00e7\u00e3o\u00a0ocorre s\u00e3o em bombas,\u00a0em\u00a0turbinas\u00a0ou h\u00e9lices\u00a0.\u00a0Nas bombas centr\u00edfugas, a cavita\u00e7\u00e3o resulta de uma\u00a0redu\u00e7\u00e3o na press\u00e3o de suc\u00e7\u00e3o\u00a0, um\u00a0aumento na temperatura de suc\u00e7\u00e3o\u00a0ou um\u00a0aumento na &#8230; <a title=\"O que \u00e9 cavita\u00e7\u00e3o em bombas centr\u00edfugas &#8211; defini\u00e7\u00e3o\" class=\"read-more\" href=\"https:\/\/www.thermal-engineering.org\/pt-br\/o-que-e-cavitacao-em-bombas-centrifugas-definicao\/\" aria-label=\"More on O que \u00e9 cavita\u00e7\u00e3o em bombas centr\u00edfugas &#8211; defini\u00e7\u00e3o\">Ler mais<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[14],"tags":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v15.4 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>O que \u00e9 cavita\u00e7\u00e3o em bombas centr\u00edfugas - defini\u00e7\u00e3o<\/title>\n<meta name=\"description\" content=\"Cavita\u00e7\u00e3o \u00e9 uma ocorr\u00eancia indesej\u00e1vel. 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