{"id":{"repo_id":"dcu","oai_identifier":"oai:doras.dcu.ie:16951"},"canonical_url":"https://search.dev.ndltd.org/etd/dcu/oai:doras.dcu.ie:16951","repository":{"repo_id":"dcu","name":"Dublin City University","base_url":"http://doras.dcu.ie/cgi/oai2"},"display":{"title":"A thermal-fluid analysis of piping dead-legs in high purity water systems","abstract":"Purified water forms an integral part of pharmaceutical production. The consistency of water quality produced by purrficatron processes and distributed to points-of-use is of utmost importance Tee-sectlons Installed in distribution loops are commonly used to divert fluid flow at take-off points. However fluid flow restriction at teesection branches can cause piping dead-legs. Dead-legs consist of reglons of stagnant fluid where harmful organisms can proliferate unaffected by the scounng effects of distribution loop flow. This thesis presents a thermo-fluld analysis focusmg upon the fluid dynamics and heat transfer mechanisms occurrmg wthin dead-leg branches A literature review of high purity water system designed etails sanitization methods currently employed in industry with reference to the detrimental effects of dead-legs. Experimentation was performed using a single-loop fluid rig complete with capped 90' tee-section representmg a piplng dead-leg. Analysis of the thermal conditions for various dead-leg configurations was performed mcludmg variations of branch length and diameter. The effect of varying loop velocity was also investigated. The application of non-intrusive analysis techniques was considered. Infrared thermography and surface-mounted thermocouples were used to map surface temperature distribution across a dead-leg branch. Increased temperatures were noted at the base of the dead-leg branch for increasing loop velocities. Comparison of reduced and equal diameter dead-legs for varying branch lengths suggested dead-leg temperature is strongly related to mlet loop velocity. Acceptable thermal responses were noted m 4d dead-legs for loop velocity > 0.94m/s, 2d reduced diameter dead-legs at 1 50m/s and in 2d equal diameter deadlegs throughout the examined velocity range. Although all dead-leg configurations used in analysis adhered to industry recommendations; unsatisfactory thermo-fluid conditions recorded for remalnlng dead-legs suggests revision of accepted regulations. Non-intrusive analyses illustrated greater temperatures at branch md-pomnt compared with base measurements. However the application of techniques was deemed limited due to pipe wall conduction effects.","abstract_html":"Purified water forms an integral part of pharmaceutical production. The consistency of water quality produced by purrficatron processes and distributed to points-of-use is of utmost importance Tee-sectlons Installed in distribution loops are commonly used to divert fluid flow at take-off points. However fluid flow restriction at teesection branches can cause piping dead-legs. Dead-legs consist of reglons of stagnant fluid where harmful organisms can proliferate unaffected by the scounng effects of distribution loop flow. This thesis presents a thermo-fluld analysis focusmg upon the fluid dynamics and heat transfer mechanisms occurrmg wthin dead-leg branches A literature review of high purity water system designed etails sanitization methods currently employed in industry with reference to the detrimental effects of dead-legs. Experimentation was performed using a single-loop fluid rig complete with capped 90' tee-section representmg a piplng dead-leg. Analysis of the thermal conditions for various dead-leg configurations was performed mcludmg variations of branch length and diameter. The effect of varying loop velocity was also investigated. The application of non-intrusive analysis techniques was considered. Infrared thermography and surface-mounted thermocouples were used to map surface temperature distribution across a dead-leg branch. Increased temperatures were noted at the base of the dead-leg branch for increasing loop velocities. Comparison of reduced and equal diameter dead-legs for varying branch lengths suggested dead-leg temperature is strongly related to mlet loop velocity. Acceptable thermal responses were noted m 4d dead-legs for loop velocity > 0.94m/s, 2d reduced diameter dead-legs at 1 50m/s and in 2d equal diameter deadlegs throughout the examined velocity range. Although all dead-leg configurations used in analysis adhered to industry recommendations; unsatisfactory thermo-fluid conditions recorded for remalnlng dead-legs suggests revision of accepted regulations. Non-intrusive analyses illustrated greater temperatures at branch md-pomnt compared with base measurements. However the application of techniques was deemed limited due to pipe wall conduction effects.","abstract_has_math":false,"creators":["Coyle, Daniel C."],"institution":"Dublin City University","degree_name":"meng","degree_level":"masters","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2007,"date_issued":"2007","date_published":"2007","updated_at":"2026-07-24T02:00:50Z","subjects":["Mechanical engineering"],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Coyle, Daniel C."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2007"]},{"key":"dc:date.issued","label":"Date","values":["2007"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["Dublin City University"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://doras.dcu.ie/16951/"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["masters"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["meng"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Mechanical engineering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://doras.dcu.ie/16951/1/Daniel_C_Coyle_SC.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Purified water forms an integral part of pharmaceutical production. The consistency of water quality produced by purrficatron processes and distributed to points-of-use is of utmost importance Tee-sectlons Installed in distribution loops are commonly used to divert fluid flow at take-off points. However fluid flow restriction at teesection branches can cause piping dead-legs. Dead-legs consist of reglons of stagnant fluid where harmful organisms can proliferate unaffected by the scounng effects of distribution loop flow. This thesis presents a thermo-fluld analysis focusmg upon the fluid dynamics and heat transfer mechanisms occurrmg wthin dead-leg branches A literature review of high purity water system designed etails sanitization methods currently employed in industry with reference to the detrimental effects of dead-legs. Experimentation was performed using a single-loop fluid rig complete with capped 90' tee-section representmg a piplng dead-leg. Analysis of the thermal conditions for various dead-leg configurations was performed mcludmg variations of branch length and diameter. The effect of varying loop velocity was also investigated. The application of non-intrusive analysis techniques was considered. Infrared thermography and surface-mounted thermocouples were used to map surface temperature distribution across a dead-leg branch. Increased temperatures were noted at the base of the dead-leg branch for increasing loop velocities. Comparison of reduced and equal diameter dead-legs for varying branch lengths suggested dead-leg temperature is strongly related to mlet loop velocity. Acceptable thermal responses were noted m 4d dead-legs for loop velocity > 0.94m/s, 2d reduced diameter dead-legs at 1 50m/s and in 2d equal diameter deadlegs throughout the examined velocity range. Although all dead-leg configurations used in analysis adhered to industry recommendations; unsatisfactory thermo-fluid conditions recorded for remalnlng dead-legs suggests revision of accepted regulations. Non-intrusive analyses illustrated greater temperatures at branch md-pomnt compared with base measurements. However the application of techniques was deemed limited due to pipe wall conduction effects."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["A thermal-fluid analysis of piping dead-legs in high purity water systems"]}]}],"canonical_facts":{"dc:creator":["Coyle, Daniel C."],"dc:date":["2007"],"dc:date.issued":["2007"],"dc:description.abstract":["Purified water forms an integral part of pharmaceutical production. The consistency of water quality produced by purrficatron processes and distributed to points-of-use is of utmost importance Tee-sectlons Installed in distribution loops are commonly used to divert fluid flow at take-off points. However fluid flow restriction at teesection branches can cause piping dead-legs. Dead-legs consist of reglons of stagnant fluid where harmful organisms can proliferate unaffected by the scounng effects of distribution loop flow. This thesis presents a thermo-fluld analysis focusmg upon the fluid dynamics and heat transfer mechanisms occurrmg wthin dead-leg branches A literature review of high purity water system designed etails sanitization methods currently employed in industry with reference to the detrimental effects of dead-legs. Experimentation was performed using a single-loop fluid rig complete with capped 90' tee-section representmg a piplng dead-leg. Analysis of the thermal conditions for various dead-leg configurations was performed mcludmg variations of branch length and diameter. The effect of varying loop velocity was also investigated. The application of non-intrusive analysis techniques was considered. Infrared thermography and surface-mounted thermocouples were used to map surface temperature distribution across a dead-leg branch. Increased temperatures were noted at the base of the dead-leg branch for increasing loop velocities. Comparison of reduced and equal diameter dead-legs for varying branch lengths suggested dead-leg temperature is strongly related to mlet loop velocity. Acceptable thermal responses were noted m 4d dead-legs for loop velocity > 0.94m/s, 2d reduced diameter dead-legs at 1 50m/s and in 2d equal diameter deadlegs throughout the examined velocity range. Although all dead-leg configurations used in analysis adhered to industry recommendations; unsatisfactory thermo-fluid conditions recorded for remalnlng dead-legs suggests revision of accepted regulations. Non-intrusive analyses illustrated greater temperatures at branch md-pomnt compared with base measurements. However the application of techniques was deemed limited due to pipe wall conduction effects."],"dc:format":["application/pdf"],"dc:identifier.uri":["https://doras.dcu.ie/16951/1/Daniel_C_Coyle_SC.pdf"],"dc:language":["en"],"dc:publisher.institution":["Dublin City University"],"dc:relation.isreferencedby":["https://doras.dcu.ie/16951/"],"dc:subject":["Mechanical engineering"],"dc:title":["A thermal-fluid analysis of piping dead-legs in high purity water systems"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["masters"],"dc:type.qualificationname":["meng"]},"updated_at":"2026-07-24T02:00:50Z"}