IIUM Engineering Journal
Not a member yet
783 research outputs found
Sort by
NUMERICAL STUDY OF ARGON EFFECT ON NITROGEN SEPARATION FROM AIR BY PRESSURE SWING ADSORPTION
Get PDFA mathematical model was used to design four modes of two-bed pressure swing adsorption (PSA) process to investigate argon presence in the feed mixture. The effect of operating parameters such as cycle time, pressure equalization, adsorption pressure, and purging flow rate was investigated. The model was validated with experimental data of nitrogen separation from the air by a single bed adsorber on carbon molecular sieve (CMS). A good agreement with experimental data is obtained. In the PSA process, higher purity of nitrogen (99.7%) was detected by mode 4 when the feed mixture was free of argon (O2: 21%, N2:79%). While the nitrogen purity was only 98.0% in the state of argon presence in the feed mixture (O2: 21%, N2: 78%, Ar: 1%). The results showed that the cycle time had insignificant effect whereas the pressure equalization and purging at low vacuum pressure had a significant effect on the process performance.
ABSTRAK: Model matematik digunakan bagi membina empat mod terdiri daripada tekanan dua-turus proses penyerapan buai (PSA) bagi menyiasat kehadiran argon dalam campuran pakan. Kesan parameter beroperasi seperti masa kitaran, penyamaan tekanan, tekanan penyerapan, dan kadar aliran penyingkiran disiasat. Model matematik tersebut disiasat melalui data eksperimen pemisahan nitrogen dari udara melalui penyerapan turus tunggal pada penapis molekular karbon (CMS). Data eksperimen yang bagus diperoleh. Dalam proses PSA, mod keempat menghasilkan ketulenan nitrogen (99.7%) lebih tinggi apabila campuran pakan bebas argon (O2: 21%, N2:79%). Sementara itu, ketulenan nitrogen hanya 98.0% apabila terdapat kehadiran argon dalam campuran pakan (O2: 21%, N2: 78%, Ar: 1%). Kajian menunjukkan masa kitaran memberi kesan tidak signifikan sementara penyamaan tekanan dan penyingkiran pada tekanan vakum rendah mempunyai kesan signifikan terhadap prestasi proses
THE CHARACTERISTICS OF REED LIGHTWEIGHT CLAY BRICKS AFTER DRYING PROCESS
Get PDFThe drying procedure is one of the basic stages in the brick making process, particularly when utilizing the extrusion framing technique. This stage decides the quality and amount of the brick samples. One of the characteristic waste vegetable materials is reed, whish is found in huge amounts in Iraq and numerous other nations. Five weight proportions of reed crumbs (5,10,15,20 and 25%) were utilized to produce lightweight clay bricks. Lab samples were shaped with dimensions of (25×38×76mm) using the vacuum extraction method. Brick properties were tested after drying to determine the values of longitudinal drying shrinkage, bulk density, and compression strength. In order to check the property of lightweight clay brick samples, the samples were burned in the furnace at a temperature of 1000°C with a burning rate of 2°C per minute. The significance of this research is to know the optimal proportions of the reed crumbs that prompts exact control of the drying procedure. This fine control brings about samples of lightweight bricks of the required dimensions and without cracks that influence their properties after drying and become more visible after burning. This knowledge will prompt the decrease of waste in raw materials and energy utilized in the manufacturing of a particular amount of lightweight bricks and, along these lines, reduce the expense of production.
ABSTRAK: Prosedur pengeringan merupakan salah satu peringkat asas dalam proses membuat bata, terutamanya apabila menggunakan teknik pembingkaian penyemperitan. Peringkat ini memutuskan kualiti dan jumlah sampel bata. Salah satu daripada bahan-bahan sayur-sayuran sisa buatan adalah buluh, ia didapati dalam jumlah besar di Iraq dan banyak negara yang berbeza. Sebanyak 5 buah berat serbuk reed (5,10,15,20 dan 25%) digunakan untuk menghasilkan bata tanah liat yang ringan. Model makmal dibentuk dengan dimensi (25 × 38 × 76mm) dengan menggunakan kaedah pengekstrakan vakum. Ciri-ciri bata telah diuji selepas pengeringan untuk menentukan nilai-nilai kepekatan pengeringan longitudinal, ketumpatan pukal dan kekuatan mampatan. Untuk memeriksa sampel tanah liat ringan tanahpropertyof, model-model tersebut dibakar dalam relau pada suhu 1000 ° C dengan kadar pembakaran 2°C seminit. Kepentingan kajian ini adalah untuk mengetahui perkadaran optimum serbuk reed yang menimbulkan kawalan tepat terhadap prosedur pengeringan. Kawalan halus ini membawa model-model bata yang ringan dari dimensi yang diperlukan dan tanpa retak yang mempengaruhi sifatnya selepas pengeringan dan menjadi lebih terlihat selepas terbakar. Pengetahuan ini akan mendorong penurunan sisa bahan mentah dan tenaga yang digunakan dalam pembuatan sejumlah bata ringan dan di sepanjang garisan ini mengurangkan perbelanjaan pengeluaran
ADAPTIVE DEVELOPMENT OF SVSF FOR A FEATURE-BASED SLAM ALGORITHM USING MAXIMUM LIKELIHOOD ESTIMATION AND EXPECTATION MAXIMIZATION
Get PDFABSTRACT: The smooth variable structure filter (SVSF) has been considered as the robust estimator. Like other filters, the SVSF needs an accurate system model and known noise statistics to approximate the posterior state. Unfortunately, the system cannot be accurately modeled, and the noise statistic is unknown in the real application. For these reasons, the performance of SVSF might be decreased or even led to divergence. Therefore, the enhancement of SVSF is required. This paper presents an Adaptive SVSF. Initially, SVSF is smoothed. To provide the ability to estimate the noise statistic, ASVSF is then derived based on maximum likelihood estimation (MLE) and expectation-maximization (EM). Additionally, the unbiased noise statistic is also approached. However, its covariance is complicatedly formulated. It might cause a negative definite symmetric matrix. Therefore, it is tuned based on the innovation covariance estimator (ICE). The ASVSF is designed to solve the online problem of Simultaneous Localization and Mapping (SLAM). Henceforth, it is termed as the ASVSF-SLAM algorithm. The proposed algorithm showed better accuracy and stability compared to the conventional algorithm in terms of root mean square error (RMSE) for both Estimated Path Coordinate (EPC) and Estimated Map Coordinate (EMC).
ABSTRAK: Penapis struktur bolehubah lembut (SVSF) telah dianggap sebagai penganggar teguh. Seperti penapis lain, SVSF memerlukan model sistem yang tepat dan statistik hingar yang diketahui bagi menganggar keadaan posterior. Malangnya, sistem tidak dapat dimodelkan dengan tepat dan statistik hingar tidak diketahui dalam aplikasi sebenar. Atas sebab-sebab ini, prestasi SVSF mungkin berkurangan, bahkan berbeza. Oleh itu, memperbaharui SVSF adalah perlu. Kajian ini adalah mengenai SVSF Mudah Suai. Pada awalnya, SVSF dilembutkan. Bagi menyediakan keupayaan anggaran statistik hinggar, ASVSF dihasilkan terlebih dahulu berdasarkan anggaran kemungkinan maksimum (MLE) dan maksimum-harapan (EM). Tambahan, statistik hinggar yang tidak berat sebelah juga dibuat. Walau bagaimanapun, rumusan formula kovarians ini adalah kompleks. Ini mungkin menyebabkan matriks simetri menjadi negatif. Oleh itu, ia diselaraskan berdasarkan penganggar kovarians inovasi (ICE). ASVSF dibina bagi menyelesaikan masalah dalam talian Penempatan dan Pemetaan Serentak (SLAM) dalam talian. Oleh itu, ia disebut sebagai algoritma ASVSF-SLAM. Algoritma yang dicadangkan ini menunjukkan ketepatan dan kestabilan yang lebih baik berbanding algoritma konvensional dari segi ralat punca min kuasa dua (RMSE) bagi kedua-dua Koordinat Anggaran Laluan (EPC) dan Anggaran Koordinat Peta (EMC)
CRACK INFLUENCE ON A PIPE WITH DOUBLE SLOPE UNDER INTERNAL PRESSURE: NUMERICAL SIMULATION WITH XFEM
Get PDFThis work analyses the effect of elliptical cracks on a pipe with double slope thickness transition, using the extended finite element method (XFEM), level sets were defined to describe the three-dimensional (3D) cracks. The Computation of the stress intensity factors (SIFs) of cracks is performed. The values of SIFs are compared between straight pipes and pipes with a double (single) slope thickness transition. The results show that the XFEM is an effective tool for modelling cracks in pipes. A pressurized pipe with double slope thickness transition is more sensitive to the defect in comparison with another type of pipe. Parameters of the transition zone have an effect on stress intensity factors, precisely, the parameters of the first thickness transition are more influential on the gravity of the defect compared to the second thickness transition.
ABSTRAK: Kajian ini menganalisa kesan retakan elips pada paip dengan peralihan ketebalan cerun berganda, menggunakan kaedah elemen terhingga dipanjangkan (XFEM), set tahap ditentukan bagi menentukan keretakan tiga dimensi (3D). Pengiraan faktor intensiti tekanan (SIF) retakan dilakukan. Nilai SIF dibandingkan antara paip lurus dan paip peralihan ketebalan cerun berganda (tunggal). Hasil kajian menunjukkan bahawa XFEM adalah alat yang berkesan bagi memodel keretakan paip. Paip bertekanan mengikut peralihan ketebalan cerun berganda, lebih sensitif terhadap kecacatan berbanding paip lain. Parameter zon peralihan mempunyai pengaruh terhadap faktor intensiti tegangan, tepatnya, parameter peralihan ketebalan pertama lebih mempengaruhi pada graviti kecacatan berbanding dengan peralihan ketebalan kedua
THE PREPARATION OF CaO-BASED PELLET USING RICE HUSK ASH VIA GRANULATION METHOD FOR POTENTIAL CO2 CAPTURE
No full textCO2 capturing has become very significant option to reduce the emission of CO2 in the atmosphere and hence, minimizing environmental issues.Among solid CO2 sorbent, calcium oxide (CaO) is an attractive regenerable sorbent for CO2 capturing because of their reactivity and high CO2 absorption capacity. CaO alone suffers from rapid decay of CO2 adsorption during multiple carbonation/calcination reaction cycles. The stability of CaO sorbents during cyclic runs can be achieved via the incorporation of additive support materials. The silica (SiO2) from natural sources such as rice husk is the best candidate to be used as an additive in the sorbents. However, the CaO-based sorbent in finely generated powders are prone to severe attrition problems. Therefore, this research focuses on preparation of CaO-based pellets by using rice husk ash (RHA) via granulation method. The result of the raw materials confirmed that Ca(OH)2 have crystalline structure with finely distributed grains and RHA exhibit amorphous structure with randomly oriented size grains. Based on the XRD, it is confirmed that the insertion of RHA does not alter the phase structure of the pellets. Each ratio yield different intensity value and has formation of new peaks after sintering. Meanwhile, the microstructures of the pellets show that the pores reduced as the calcination temperature increased while the incorporation of RHA caused the pores size increased with randomly oriented shape. These findings indicate that the optimum value for the pellets is with the Ca(OH)2:RHA ratio of 80:20 and calcination temperature of 750 °C.
ABSTRAK: Penangkapan CO2 telah menjadi pilihan yang sangat penting untuk mengurangkan pelepasan CO2 di atmosfer serta kesan alam sekitar. Antara penjerap CO2 pepejal, kalsium oksida (CaO) adalah penyerapan yang menarik untuk CO2 yang ditangkap kerana kereaktifan dan kapasiti penyerapan CO2 yang tinggi. CaO sahaja menderita daripada pelepasan cepat penjerapan CO2 semasa kitaran tindakbalas karbonasi / kalsinasi. Kestabilan CaO penjerap semasa berlaku kitaran boleh dicapai melalui penggabungan bahan sokongan tambahan. Silika (SiO2) dari sumber semula jadi seperti sekam padi (RHA) adalah calon terbaik untuk digunakan sebagai aditif dalam penjerap. Walau bagaimanapun, penjerap berasaskan CaO dalam bentuk serbuk halus yang dihasilkan adalah terdedah kepada masalah pergeseran yang teruk. Oleh itu, kajian ini memberi tumpuan kepada penyediaan pelet berasaskan CaO dengan menggunakan abu sekam beras melalui kaedah granulasi. Hasil bahan mentah mengesahkan bahawa Ca(OH)2 mempunyai struktur kristalografi dengan bijirin halus dan RHA yang mempamerkan struktur bukan kristal dengan butiran saiz berorientasikan secara rawak. Berdasarkan XRD, ia disahkan bahawa penyisipan RHA tidak mengubah struktur kristalografi pelet. Setiap nisbah menghasilkan nilai intensiti yang berbeza dan mempunyai pembentukan puncak baru selepas pensinteran. Sementara itu, mikrostruktur pelet menunjukkan bahawa pori-pori berkurangan apabila suhu kalsinasi meningkat sementara pembentukan RHA menyebabkan saiz pori meningkat dengan bentuk berorientasikan rawak. Penemuan ini menunjukkan bahawa nilai optimum bagi pelet adalah dengan nisbah Ca(OH)2:RHA 80:20 dan suhu kalsinasi 750 °C
EFFECT OF FERRO ELECTRIC THICKNESS ON NEGATIVE CAPACITANCE FET (NCFET)
Get PDFConventional Field Effect Transistor (FET) are well known to require at least 60mV/decade at 300K change in the channel potential to change the current by a factor of 10. Due to this, 60mV/decade becomes the bottleneck of this day transistor. A comprehensive study of the Negative Capacitance Field Effect Transistor (NCFETis presented. This paper shows the effect of ferroelectric material in MOSFET structure by replacing the insulator in the conventional MOSFET. It should be possible to obtain a steeper subthreshold swing (SS) compared to the one without a ferroelectric material layer, thus breaking the fundamental limit on the operating voltage of MOSFET. 27% of the subthreshold slope reduction is observed by introducing ferroelectric in the dielectric layer compared to the conventional MOSFETs. Hence, the power dissipation in MOSFET can be mitigated and shine to a new technology of a low voltage/low power transistor operation.
ABSTRAK: Transistor Kesan Medan Konvensional (FET) terkenal memerlukan sekurang-kurangnya 60mV / dekad pada 300K perubahan pada saluran yang berpotensi untuk mengubah arus dengan faktor 10. Oleh kerana itu, 60mV / dekad menjadi hambatan transistor hari ini. Kajian komprehensif mengenai Negative Capacitance Field Effect Transistor (NCFETis dikemukakan. Makalah ini menunjukkan kesan bahan ferroelektrik dalam struktur MOSFET dengan mengganti penebat dalam MOSFET konvensional. Sebaiknya dapatkan swing swing subthreshold (SS) yang lebih curam berbanding dengan satu tanpa lapisan bahan ferroelektrik, sehingga melanggar had asas pada voltan operasi MOSFET. 27% pengurangan cerun subthreshold diperhatikan dengan memperkenalkan ferroelektrik di lapisan dielektrik berbanding dengan MOSFET konvensional. Oleh itu, pelesapan daya dalam MOSFET dapat dikurangkan dan bersinar dengan teknologi baru operasi transistor voltan rendah / kuasa rendah
THE EFFECTS OF CERIUM PROMOTER ON THE PERFORMANCE OF COBALT-BASED CATALYSTS IN FISCHER TROPSCH SYNTHESIS FOR LIQUID FUEL PRODUCTION
Get PDFAn intensive work of Fischer-Tropsch synthesis (FTS) on a cobalt-based catalyst supported with cerium as a promoter was presented. The influence of space velocity and inlet gas feed ratio on FTS reaction performance was studied for the synthesized catalysts. Incipient wetness impregnation method was utilized to synthesis both unpromoted (25%Co/?-Al2O3) and cerium promoted (1%Ce-25%Co/?-Al2O3) catalysts. The proposed catalysts were examined by N2 adsorption and temperature-programed reduction (TPR). The performance of Ce-promoted and unpromoted cobalt-based catalysts in FTS was assessed in terms of activity and selectivity to desired products (C5+). The obtained results revealed that the addition of cerium by impregnation notably favours the reducibility of cobalt oxides by reducing the reduction temperature. In addition, the promoted catalysts exhibited higher activity and selectivity toward desired products at low space velocity and high inlet gas feed ratio as compared with the unpromoted catalysts. In conclusion, a cerium based cobalt catalyst considered as a suitable candidate to be used in gas to the liquid conversion process.
ABSTRAK: Kajian intensif sintesis Fischer-Tropsch (FTS) adalah tentang pemangkin berasas kobalt bersama penggalak cerium. Pengaruh tindak balas FTS pada halaju ruang dan nisbah suapan gas masuk dikaji menggunakan pemangkin yang disintesis. Kaedah impregnasi insipien basah telah digunakan bagi mensintesis pemangkin bukan penggalak (25%Co/?-Al2O3) dan penggalak cerium (1%Ce-25%Co/?-Al2O3). Pemangkin ini diuji dengan penjerapan N2 dan pengurangan suhu terprogram (TPR). Hasil tindak balas penggalak-Ce dan bukan penggalak berasas kobalt dalam FTS diperiksa dari segi aktiviti dan pemilihan hasil (C5+). Tindak balas menunjukkan dengan penambahan cerium melalui kaedah impregnasi dengan ketara mengurangkan kobalt oksida bersama pengurangan suhu. Di samping itu, pemangkin penggalak menunjukkan aktiviti dan pemilihan ke arah hasil pada halaju ruang dan nisbah suapan gas masuk yang tinggi berbanding dengan pemangkin bukan penggalak. Kesimpulan, pemangkin kobalt berasas cerium dianggap sesuai sebagai pemangkin sintesis bagi digunakan dalam proses penukaran gas ke cecair
ADAPTIVE SYSTEM OF FUZZY-LOGICAL REGULATION BY THE TEMPERATURE MODE OF THE DRUM BOILER
No full text The article discusses the creation of an adaptive system for managing dynamic objects based on neuro-fuzzy technology. This technology is used to actively identify and create temperature control algorithms for the superheated steam of a drum boiler in the presence of disturbances associated with a change in load. To solve this problem, the use of a fuzzy-logical controller is proposed. The rule base of this regulator is defined. A technique is proposed for determining the optimal number of neurons and the number of hidden layers. The neuro-fuzzy model of the controller is presented in the form of a multilayer neural network without feedback, which is characterized by a simple implementation in practice. The use of a fuzzy-logical controller gives the automatic control system the ability to maintain technological parameters at a given level in the presence of external disturbing influences, and also makes it possible to efficiently control the process.
ABSTRAK: Artikel ini membincangkan rekaan sistem penyesuaian bagi mengurus objek dinamik berdasarkan teknologi neura-kabur. Teknologi ini digunakan bagi mengenal pasti secara aktif dan mencipta algoritma kawalan suhu bagi stim melampau panas dalam drum dandang dengan kehadiran gangguan berkaitan perubahan beban. Bagi menyelesaikan masalah ini, penggunaan pengawal logik-kabur telah dicadangkan. Asas peraturan bagi pengaturan ini ditentukan. Satu teknik dicadangkan bagi mendapat bilangan optima neuron dan bilangan lapisan tersembunyi. Model neura-kabur pengawal ini dikemukakan dalam bentuk rangkaian neural berlapis tanpa suap balik, bercirikan praktik pelaksanaan mudah. Penggunaan pengawal logik-kabur memberi sistem kawalan automatik kebolehan mengekalkan parameter teknologi pada tahap tertentu dengan kehadiran pengaruh gangguan luar, dan juga memberi kebolehan proses kawalan yang cekap.
 
MECHANICAL PROPERTIES, MORPHOLOGY, AND HYDROLYTIC DEGRADATION BEHAVIOR OF POLYLACTIC ACID / THERMOPLASTIC POLYURETHANE BLENDS
No full textPolylactic acid (PLA) has attracted tremendous interest to be utilized as the replacement for petroleum-based polymers as it possesses good biodegradability, can be derived from renewable sources, and shows high mechanical strength. However, its inherent brittleness and low toughness has limited its usage in broader applications. In this work, PLA was melt blended with tough thermoplastic polyurethanes (TPU) in order to produce eco-friendly polymeric materials with balanced mechanical properties. Moreover, the miscibility and the hydrolytic degradation behaviour of PLA/TPU blends were also investigated as it is important to control material degradation behaviour in some applications. Five compositions of specimens, i.e. neat PLA, PLA/TPU 75/25 vol%, PLA/TPU 50/50 vol%, PLA/TPU 25/75 vol%, and neat TPU, were prepared by melt blending PLA with TPU using an internal mixer, followed by compression moulding. Tensile and impact tests were performed to evaluate the mechanical properties. From the tests, it was apparent that the elongation-at-break and impact strength of the blends increased as the TPU content increased. Dynamic Mechanical Analysis (DMA) and Scanning Electron Microscopy (SEM) observation were conducted to evaluate the miscibility of PLA/TPU blends. DMA results of the blends revealed two tangent delta peaks, indicating that the blends were immiscible, and the SEM micrographs supported this trend. Finally, hydrolytic degradation behaviour of PLA, TPU and PLA/TPU blends was investigated by measuring the weight loss after immersion of the specimens in alkaline solution at a predetermined time, i.e. every 24 hours for up to 8 days. It was found that the degradation behaviour is affected by blend composition, where PLA/TPU 50/50 vol% showed the fastest degradation rate. This result might be ascribed to the co-continuous morphology shown in the PLA/TPU blend 50/50 vol%.
ABSTRAK: Polilaktik asid (PLA) telah menarik banyak minat untuk digunakan sebagai pengganti polimer berasaskan petroleum, kerana ia mempunyai biodegradabiliti yang baik, boleh diperolehi daripada sumber yang boleh diperbaharui, dan mempunyai kekuatan mekanikal yang tinggi. Walau bagaimanapun, kerapuhan dan keliatannya yang rendah telah menghadkan penggunaannya dalam aplikasi yang lebih luas. Dalam kajian ini, leburan PLA dicampurkan dengan poliuretan thermoplastik (TPU) bagi menghasilkan bahan polimer yang mesra alam beserta dengan sifat-sifat mekanikal yang seimbang. Selain itu, daya kebolehcampuran dan degradasi hidrolitik daripada campuran PLA/ TPU juga telah dikaji kerana bagi sesetengah aplikasi, faktor degradasi adalah sangat penting. Bagi menghasilkan lima komposisi sampel, iaitu PLA tulen, PLA/TPU 75/25 vol%, PLA/TPU 50/50 vol%, PLA/TPU 25/75 vol%, dan TPU tulen, PLA dan TPU telah dicairkan dan diadun menggunakan mesin pencampur internal, diikuti dengan kaedah pengacuan kompresi. Untuk mengkaji sifat-sifat mekanikal, ujian regangan dan impak telah dijalankan. Hasil ujian tersebut menunjukkan peningkatan nilai pemanjangan pada titik putus dan kekuatan impak, seiring dengan peningkatan komposisi TPU. Manakala, penilaian daya kebolehcampuran diantara PLA dan TPU dijalankan menggunakan analisis mekanikal dinamik (DMA) dan mikroskop pengimbas elektron (SEM). Keputusan DMA, hasil daripada campuran tersebut mendedahkan dua puncak tangen delta, menunjukkan bahawa dua campuran tersebut tidak memiliki daya bolehcampur yang baik. Kesimpulan ini disokong pula oleh gambar mikro dari hasil ujian SEM. Akhir sekali, degradasi hidrolitik PLA, TPU dan campuran PLA/TPU dikaji melalui pengukuran berat sampel setelah direndam di dalam larutan alkali pada masa yang ditetapkan, iaitu setiap 24 jam sehingga 8 hari. Hasil daripada ujian tersebut mendapati degradasi hidrolitik dipengaruhi oleh komposisi campuran. Campuran PLA/TPU dengan komposisi 50/50 vol% menunjukkan kadar penurunan berat yang paling cepat. Hasil ujian ini mungkin boleh dikaitkan dengan sifat morfologi co-continuous yang ditunjukkan dalam campuran PLA/TPU 50/50 vol%
ANALYSIS AND CORRELATIONS OF DIMENSIONLESS NUMBERS RELEVANT TO ORIFICES’ CAVITATING FLOW
Get PDFThe aim of this work was to establish a general design basis for pilot-scale units to treat textile dyeing wastewater containing recalcitrant organic chemicals by hydrodynamic cavitation (HC) using orifices of various geometries. Relevant tabulated data available in the literature were analyzed and correlated to obtain universal relationships to this end. In spite of extensive effort, most of the obtained correlations were system-specific, which still can be used for design using their respective orifice geometries as demonstrated. However, one salient general relationship links the pipe’s dimensionless loss coefficient (KLP) to the pipe’s Reynolds number (ReP), encompassing all data under consideration, which may serve as an additional design option to optimize such units. The implication of this relationship is a lower upstream pressure (P1) value with an increase in pipe diameter while using the same specified orifice and achieving the same desired cavitation number (Cv). The ratio of P1 value in the larger pipe to its value in the smaller pipe is a function of the smaller pipe diameter (DS) to the larger pipe diameter (DL) ratio: (P1 in DL) / (P1 in DS) = (DS /DL)2.33. A lower P1 value will increase the cavitation yield by decreasing the expended energy, especially if the required number of passes is large. Additionally, the variation of the orifices’ hole loss coefficient (KLh) with the ratio of the holes area to the pipe cross-sectional area (Ah/Ap) for cavitating flow is compared with that for non-cavitating/incipient cavitation flow reported in the literature.
ABSTRAK: Tujuan kajian ini diadakan bagi mereka bentuk dasar umum unit skala-pandu bagi merawat pewarnaan air buangan tekstil yang mengandungi kimia organik rekalsitran daripada peronggaan hidrodinamik (HC) menggunakan orifis pelbagai geometri. Data berjadual berkaitan yang ada dalam kajian lepas dianalisa dan dikaitkan bagi mendapatkan kaitan universal hingga akhir. Walaupun pelbagai usaha telah dijalankan, banyak kaitan didapati mengguna pakai sistem-tertentu, di mana boleh digunakan bagi mereka cipta menggunakan geometri orifis yang ditunjukkan. Walau bagaimanapun, bagi menghubung kait pekali langsung tanpa dimensi (KLP) kepada paip nombor Reynolds (ReP), meliputi semua data di bawah pertimbangan, di mana membantu pilihan rekaan tambahan bagi mengoptimum unit tersebut. Implikasi hubungan ini adalah nilai tekanan hulu sungai bawah (P1) dengan penambahan diameter paip dengan menggunakan orifis sama yang sebenar dan mendapati nombor peronggaan yang sama diingini (Cv). Nisbah nilai P1 dalam paip besar kepada nilai paip kecil adalah berkadaran pada nisbah diameter paip kecil (DS) kepada diameter paip besar (DL):
(P1 dalam DL) / (P1 in DS) = (DS /DL)2.33