{"id":5755,"date":"2023-05-14T12:03:15","date_gmt":"2023-05-14T12:03:15","guid":{"rendered":"https:\/\/seadonna.com\/blog\/?p=5755"},"modified":"2023-06-02T17:28:13","modified_gmt":"2023-06-02T17:28:13","slug":"plate-type-heat-exchanger-meo-class-4-marine-engineer-study-guide","status":"publish","type":"post","link":"https:\/\/seadonna.com\/blog\/plate-type-heat-exchanger-meo-class-4-marine-engineer-study-guide\/","title":{"rendered":"PLATE TYPE HEAT EXCHANGER | MEO CLASS 4 | MARINE ENGINEER STUDY GUIDE"},"content":{"rendered":"

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The obvious feature of plate type heat exchangers, is that they are easily opened for cleaning.<\/p>\n

The major advantage over tube type coolers, is that their higher efficiency is reflected in a smaller size for the same cooling capacity.<\/p>\n

They are made up from an assembly of identical metal pressings with horizontal or chevron pattern corrugations; each with a nitrile rubber joint.<\/p>\n

The plates, which are supported beneath and located at the top by parallel metal bars, are held together against an end plate by clamping bolts.
\nFour branch pipes on the end plates, align with ports in the plates through which two fluids pass. Seals around the ports are so arranged that one fluid flows in alternate passages between plates and the second fluid in the intervening passages, usually in opposite directions.<\/p>\n

The plate corrugations promote turbulence\u00a0 in the flow of both fluids and so encourage efficient heat transfer.<\/p>\n

Turbulence as opposed to smooth flow causes more of the liquid passing between the plates to come into contact with them. It also breaks up the boundary layer of liquid which tends to adhere to the metal and act as a heat barrier when flow is slow. The corrugations make the plates stiff so permitting the use of thin material. They additionally increase plate area. Both of these factors also contribute to heat exchange efficiency.<\/p>\n

Excess turbulence, which can result in erosion of the plate material, is avoided by using moderate flow rates. However, the surfaces of plates which are exposed to sea water are liable to corrosion\/erosion and suitable materials must be selected. Titanium plates although expensive, have the best resistance to corrosion\/erosion. Stainless steel has also been used and other materials such as aluminium-brass. The latter may not be ideal for vessels which operate in and out of ports with polluted waters.<\/p>\n

The nitrile rubber seals are bonded to the plates with a suitable adhesive.<\/p>\n

Removal is facilitated with the use of liquid nitrogen which freezes, makesbrittle and causes contraction of the rubber seal which is then easily broken away. Other methods of seal removal result in plate damage.
\nNitrile rubber is suitable for temperatures of up to about 110\u00b0C. At higher temperatures the rubber hardens and loses its elasticity. The joints are squeezed when the plates are assembled and clamping bolts are tightened after cleaning.<\/p>\n

Overtightening can cause damage to the plates, as can an incorrect tightening procedure. A torque spanner can be used as directed when clamping bolts are tightened. cooler stack dimensions can also be checked.<\/p>\n

\"\"<\/p>\n","protected":false},"excerpt":{"rendered":"

The obvious feature of plate type heat exchangers, is that they are easily opened for cleaning. The major advantage over tube type coolers, is that their higher efficiency is reflected in a smaller size for the same cooling capacity. They are made up from an assembly of identical metal pressings with horizontal or chevron pattern […]<\/p>\n","protected":false},"author":1,"featured_media":5757,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[79],"tags":[],"class_list":["post-5755","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-marine-engineering-competency-exams-study-blogs"],"_links":{"self":[{"href":"https:\/\/seadonna.com\/blog\/wp-json\/wp\/v2\/posts\/5755","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/seadonna.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/seadonna.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/seadonna.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/seadonna.com\/blog\/wp-json\/wp\/v2\/comments?post=5755"}],"version-history":[{"count":1,"href":"https:\/\/seadonna.com\/blog\/wp-json\/wp\/v2\/posts\/5755\/revisions"}],"predecessor-version":[{"id":5758,"href":"https:\/\/seadonna.com\/blog\/wp-json\/wp\/v2\/posts\/5755\/revisions\/5758"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/seadonna.com\/blog\/wp-json\/wp\/v2\/media\/5757"}],"wp:attachment":[{"href":"https:\/\/seadonna.com\/blog\/wp-json\/wp\/v2\/media?parent=5755"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/seadonna.com\/blog\/wp-json\/wp\/v2\/categories?post=5755"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/seadonna.com\/blog\/wp-json\/wp\/v2\/tags?post=5755"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}