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"ABSTRACT The aim of the paper is to present the influence of selected deflocculants on decreasing the hydromixture viscosity and as a consequence decreasing the wall shear stresses in a flowing medium. Adding deflocculants to improve the conditions encountered in a pipelineduring the hydromixture flow is called chemical processing. The experimental studies presentedin the article were performed for a hydromixture with a mass concentration of 20% and 43%consisting mostly of solids with the averaged diameter equal to 45.5 μm. The measurements wereperformed for varied doses of deflocculants in three proportions in a wide range of shear rates.The results of experiments have confirmed that the influence of the deflocculant on the wallshear stress is complex as there is an opposing phenomenon strongly depending on the dosesof deflocculant samples. The results of the experiments are discussed and major conclusions aredrawn."

"ABSTRAKTransport characteristic adalah salah satu rheology ice slurry yang perlu diteliti. Transport characteristic adalah satuan energi pendinginan yang didapatkan dari ice slurry yang dialirkan dengan variasi kecepatan tertentu. Pada penelitian ini, ice slurry dibuat menggunakan campuran air tawar dengan 20% Monoethylene Glycol sebagai freezing depressant. Ice Slurry ini dibuat dengan ice slurry generator pada Laboratorium Pendingin Departemen Teknik Mesin Fakultas Teknik Universitas Indonesia yang mencapai suhu terendah -15 dengan 12 jam waktu pengoperasian. Ice slurry yang dialirkan pada pipa 1/2 inci dengan panjang pipa 2 meter ini menghasilkan ice mass fraction sebesar 40% dengan variasi kecepatan 0,34 hingga 1,00 meter per detik. Transport characteristic terbesar yang didapatkan dalam penelitian ini sebesar 173,50 kW.

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ABSTRACTTransport characteristic is one of the rheology of ice slurry that needs to be studied. Transport characteristic is a unit of cooling energy obtained from ice slurry which is supplied with a certain variation of speed. In this study, ice slurry was made using a mixture of fresh water with 20% Monoethylene Glycol as a freezing depressant. This Ice Slurry is made with ice slurry generator in the Cooling Laboratory of the Mechanical Engineering Department of the Faculty of Engineering, University of Indonesia, which reaches the lowest temperature of -15 ℃ with 12 hours of operating time. The ice slurry flowed in the 1/2 inch pipe with a 2 meter pipe length produces an ice mass fraction of 40% with a speed variation of 0.34 to 1.00 meters per second. The biggest transport characteristic obtained in this study was 173.50 kW."

"Silica sand slurry is a multiphase flow that consists of liquid and particle solids. Slurry flow characteristics are affected by particle size, particle distribution, particle concentrate, pipe geometry, flow regime, and viscosity factors. Spiral pipe is one of the solutions to increase drag reduction at a certain velocity and Reynolds number (Re). The aim of this experiment is to figure out the influence of using spiral pipe in increasing drag reduction of silica sand slurry flow. The pipeline used is spiral pipe with a helicial tape with two ratios of pitch per diameter (p/D), i.e. = 4 and 7. The test loop is set up as 3,500 mm (3.5 meters) in length. The size of the particle is 1 mm in diameter. The mean density of the silica sand particles is 2,300 kg/m3. The velocities are set between 1m/second and 5m/second. The percentage of volumetric concentration of solids in slurry (Cw) varies between 20%, 30%, and 50% in weight. Particle concentration, the Reynolds number and ratio of pitch and diameter give significant impact to the drag reduction. At a ratio of pitch/diameter (p/Di) = 7, at a Reynolds number (Re) of 30,000 and at Cw 50% can increase drag reduction to about 33%."