title: Fouling and pressure drop analysis of milk powder deposition on the front of parallel fins

authors: Walmsley, Timothy Gordon

subjects: fouling

abstract: One method to reduce the energy consumption of industrial milk spray dryers is to recover waste heat from the exhaust dryer air. A significant challenge associated with this opportunity is the air contains a small amount of powder that may deposit on the face and surfaces of a recuperator. This paper introduces a novel lab based test that simulates powder deposition on a bank of parallel plate fins at exhaust dryer air conditions. The fin bank acts like the face of a typical finned tube row in a recuperator. The aim of this study is to look at how deposition on the front of fins is affected by the air conditions. Results show similar characteristics to other milk powder deposition studies that exhibit a dramatic increase in deposition once critical stickiness levels are reached. As powder deposits on the face of the fins, the pressure drop across the bank increases until eventually an asymptote occurs, at which point the rates of deposition and removal are similar. For very sticky conditions, deposition on the face of the fins can cause a rise in the pressure drop by as much as 65%. The pressure drop has also been successfully related to the percentage of open frontal area of the fins with and without deposition. Deposition inside and at the rear of the fin bank was found to be minimal.

text: Fouling and pressure drop analysis of milk powder deposition on the front of parallel fins One method to reduce the energy consumption of industrial milk spray dryers is to recover waste heat from the exhaust dryer air. A significant challenge associated with this opportunity is the air contains a small amount of powder that may deposit on the face and surfaces of a recuperator. This paper introduces a novel lab based test that simulates powder deposition on a bank of parallel plate fins at exhaust dryer air conditions. The fin bank acts like the face of a typical finned tube row in a recuperator. The aim of this study is to look at how deposition on the front of fins is affected by the air conditions. Results show similar characteristics to other milk powder deposition studies that exhibit a dramatic increase in deposition once critical stickiness levels are reached. As powder deposits on the face of the fins, the pressure drop across the bank increases until eventually an asymptote occurs, at which point the rates of deposition and removal are similar. For very sticky conditions, deposition on the face of the fins can cause a rise in the pressure drop by as much as 65%. The pressure drop has also been successfully related to the percentage of open frontal area of the fins with and without deposition. Deposition inside and at the rear of the fin bank was found to be minimal.

year: 2013

title: Failure analysis of some Toyota Prius battery packs and potential for recovery

authors: Leijen, Peter

subjects: Toyota Prius

abstract: The Toyota Prius battery pack consists of 38 individual battery blades, each blade contains 6 NiMH cells in series. This means that each pack contains 228 NiMH cells. Each cell has the potential to fail. This report investigates the mode of failure of Prius battery packs by first analysing a number of packs in the lab, and then road testing them in a Toyota Prius. The analysis of the battery packs shows that some packs had aged “linearly”, that is in a balanced manner, such that the state of health of all blades remained similar. However, in other packs discrete blades had significantly different states of health. A pack that consists of cells that are matched in both state of health and state of charge delivers the best performance. The research also showed that the worst cell in the pack determines the overall pack performance. This was demonstrated by substituting reducedcapacity or short-circuited blades into a functioning battery pack. A vehicle with a pack consisting of 37 2400 mAh battery blades and one 1200 mAh battery blade was only able to drive 1.3 km in Electric Vehicle mode, as opposed to 2.6 km with a pack consisting of 38 2400 mAh battery blades.

text: Failure analysis of some Toyota Prius battery packs and potential for recovery The Toyota Prius battery pack consists of 38 individual battery blades, each blade contains 6 NiMH cells in series. This means that each pack contains 228 NiMH cells. Each cell has the potential to fail. This report investigates the mode of failure of Prius battery packs by first analysing a number of packs in the lab, and then road testing them in a Toyota Prius. The analysis of the battery packs shows that some packs had aged “linearly”, that is in a balanced manner, such that the state of health of all blades remained similar. However, in other packs discrete blades had significantly different states of health. A pack that consists of cells that are matched in both state of health and state of charge delivers the best performance. The research also showed that the worst cell in the pack determines the overall pack performance. This was demonstrated by substituting reducedcapacity or short-circuited blades into a functioning battery pack. A vehicle with a pack consisting of 37 2400 mAh battery blades and one 1200 mAh battery blade was only able to drive 1.3 km in Electric Vehicle mode, as opposed to 2.6 km with a pack consisting of 38 2400 mAh battery blades.

year: 2011

title: Hangarau me te Māori: Māori and technology

authors: Keegan, Te Taka Adrian Gregory

subjects: Māori

abstract: A sign of a vibrant, healthy developing nation is the adaptation and uptake of new technologies. Māori have a long, but mostly unrecognised, history of ingenious innovation and adaption of new technologies. This chapter will reveal Māori ingenuity through discussion of historic examples and modern media usages by Māori, and the future implications these have for Māori.
Technology can be defined as tools, devices and machines that have been developed by the application of scientific knowledge. Māori technology, then, is Māori tools, devices and machines that have been developed by the application of Māori scientific knowledge. This chapter discusses some examples of innovative Māori technology and their adoption in both historic and modern times. It includes sections on historic Māori technology, Māori media innovation and Māori adoption of Internet technology. Two sections are further expanded on: Māori in social networking sites and te reo Māori in technology. The chapter concludes with the authors' thoughts on how the adoption of new technologies will shape tikanga Māori and te reo Māori into the future.

text: Hangarau me te Māori: Māori and technology A sign of a vibrant, healthy developing nation is the adaptation and uptake of new technologies. Māori have a long, but mostly unrecognised, history of ingenious innovation and adaption of new technologies. This chapter will reveal Māori ingenuity through discussion of historic examples and modern media usages by Māori, and the future implications these have for Māori.
Technology can be defined as tools, devices and machines that have been developed by the application of scientific knowledge. Māori technology, then, is Māori tools, devices and machines that have been developed by the application of Māori scientific knowledge. This chapter discusses some examples of innovative Māori technology and their adoption in both historic and modern times. It includes sections on historic Māori technology, Māori media innovation and Māori adoption of Internet technology. Two sections are further expanded on: Māori in social networking sites and te reo Māori in technology. The chapter concludes with the authors' thoughts on how the adoption of new technologies will shape tikanga Māori and te reo Māori into the future.

year: 2018