scholarly journals Microwave drying of olefins from drill cuttings and analysis of the organic phase recovered during drying operation

Author(s):  
Ana C. S. Mota ◽  
Jéssika M. Santos ◽  
Marina S. Pereira ◽  
Carlos H. Ataíde

The main objective of the present work was to study the influence of different operating conditions in the microwave drying of drill cuttings and an eventual degradation of the condensed liquid collected during this operation. For this, a Central Composite Design (CCD) was used, considering three independent variables at three levels: initial olefin content (7.5, 10, and 12.5% w/w), power (250, 500, and 750 W), and time (5, 10, and 15 min); the residual olefin content being the response analyzed in the conducted tests without monitoring or control of the cutting’s temperature. All three variables studied were statistically significant, presenting a positive or negative effect on residual olefin content. As expected, the initial olefin content had a negative effect on the response. On the other hand, when considering the applied power and the drying time, the effect on decontamination yield was positive. The results showed that cuttings can be decontaminated at lower levels than those required by environmental legislation (offshore drilling), reaching residual olefin mass contents of less than 1%. Finally, the organic phase of recovered liquids, after the condensation of vapors produced during drying, was analyzed by gas chromatography technique. It was observed greater olefin degradation in the longer and higher power tests, especially in samples of condensed liquid collected inside the microwave oven.

Author(s):  
Magesh Ganesh Pillai ◽  
Iyyasamy Regupathi ◽  
Lima Rose Miranda ◽  
Thanapalan Murugesan

The drying characteristics of plaster of paris (POP) under microwave conditions at different microwave power input, initial moisture content, sample thickness and drying time were studied. Further the experimental data on moisture ratio of POP for different operating conditions were obtained and calculations were made using nine basic drying model equations. The appropriate model with modified constants and coefficients to represent the drying kinetics of POP was found through the analysis of the statistical analysis. The effective moisture diffusivity of the drying process was also computed for different experimental conditions and a relationship between the drying rate constant and the effective moisture diffusivity was obtained. The energy consumption for microwave drying of plaster of paris at different experimental conditions were also computed.


2020 ◽  
Vol 12 (2) ◽  
pp. 115-130
Author(s):  
Leidy Laura Cruz-de la Cruz ◽  
Teodoro Espinosa-Solares ◽  
Miguel Angel Aguilar-Méndez ◽  
Diana Guerra-Ramírez ◽  
Guadalupe Hernández-Eugenio

Introduction: The drying of nopal offers an alternative for their preservation, storage, handling and consumption. Objective: The effects of microwave drying on the microstructural characteristics of nopal and their thermodynamic properties at the food-water interface were evaluated. Methodology: Nopal cladodes were microwave-dried by applying powers of 75 and 158 kW∙kg-1. Microstructure of the samples was evaluated by Scanning Electron Microscope. Adsorption isotherms were determined at temperatures of 10, 20, 30 and 40 °C. Net isosteric heat (q-st) was calculated using the Clausius-Clapeyron equation and the Peleg model. Results: Samples dehydrated at 75 kW∙kg-1 showed greater preservation of their internal and external structure. When applying a higher power (158 kW∙kg-1), greater damage was observed in the microstructure of the material. Type III adsorption isotherm curves were obtained according to the Brunauer classification. The q-st of the dehydrated nopal was 7.51 kJ∙mol-1 for a moisture content of 0.05 kgH2O∙kg-1. Limitations of the study: The results obtained are valid only for microwave drying by applying powers of 75 and 158 kW∙kg-1. Originality: This work proposes the microwave drying of nopal as an alternative method that reduces drying time and allows the preservation of the material’s structural properties. Conclusions: The power applied in the microwave drying of nopal had a direct impact on the microstructure of the samples. The use of a power of 75 kW∙kg-1 was the best drying condition to preserve the structures constituting the cladodes.


2020 ◽  
pp. 108201322098133
Author(s):  
Sagar Nagvanshi ◽  
Subbarao Kotra Venkata ◽  
TK Goswami

Microwave drying works on the volumetric heating concept promoted by electromagnetic radiation at 0.915 or 2.450 GHz. In this study, banana ( Musa Cavendish) was taken as the sample and treated under microwave drying. The effect of two process variables, namely slice thickness (2, 3.5, and 5 mm) and microwave power (180 W, 360 W, and 540 W), were studied on drying kinetics and color kinetics. It was observed that the inverse variation relationship exists between drying time and microwave power level while drying time and slice thickness exhibited a direct variation relationship. A Computer Vision System (CVS) was developed to measure the color values of banana in CIELab space using an algorithm written in MATLAB software. Once the color parameters were obtained, they were fitted in First and Zero-order kinetic models. Both models were found to describe the color values adequately. This study concludes that microwave drying is a promising dehydration technique for banana drying that reduces the significant time of drying. Application of CVS is an excellent approach to measure the surface color of banana.


2020 ◽  
Vol 5 (1) ◽  
pp. 563-572
Author(s):  
Iman Golpour ◽  
Mohammad Kaveh ◽  
Reza Amiri Chayjan ◽  
Raquel P. F. Guiné

AbstractThis research work focused on the evaluation of energy and exergy in the convective drying of potato slices. Experiments were conducted at four air temperatures (40, 50, 60 and 70°C) and three air velocities (0.5, 1.0 and 1.5 m/s) in a convective dryer, with circulating heated air. Freshly harvested potatoes with initial moisture content (MC) of 79.9% wet basis were used in this research. The influence of temperature and air velocity was investigated in terms of energy and exergy (energy utilization [EU], energy utilization ratio [EUR], exergy losses and exergy efficiency). The calculations for energy and exergy were based on the first and second laws of thermodynamics. Results indicated that EU, EUR and exergy losses decreased along drying time, while exergy efficiency increased. The specific energy consumption (SEC) varied from 1.94 × 105 to 3.14 × 105 kJ/kg. The exergy loss varied in the range of 0.006 to 0.036 kJ/s and the maximum exergy efficiency obtained was 85.85% at 70°C and 0.5 m/s, while minimum exergy efficiency was 57.07% at 40°C and 1.5 m/s. Moreover, the values of exergetic improvement potential (IP) rate changed between 0.0016 and 0.0046 kJ/s and the highest value occurred for drying at 70°C and 1.5 m/s, whereas the lowest value was for 70°C and 0.5 m/s. As a result, this knowledge will allow the optimization of convective dryers, when operating for the drying of this food product or others, as well as choosing the most appropriate operating conditions that cause the reduction of energy consumption, irreversibilities and losses in the industrial convective drying processes.


2011 ◽  
Author(s):  
Boyun Guo ◽  
Jun Li ◽  
Shuhua Lin

Author(s):  
Lozica Ivanović ◽  
Miloš Matejić

Gerotor pumps are well known by a compact design, simple structure and low noise level, which makes them suitable for use in the automotive industry, and especially in hydraulic systems for engine lubrication. One of the main disadvantages of gerotor pumps is the inability to adjust to wear, which significantly reduces the pump efficiency. In order to mitigate the negative effect of the inevitable wear process, this paper presents a methodology for determining the optimal combination of trochoid gears design parameters for a defined aspect. An appropriate mathematical model has been developed to analyze the effect of changes in gear design parameters in relation to maximum contact stresses, pressure changes in gerotor pump chambers and wear rate proportional factor (WRPF). Verification of the developed models was performed by realizing physical pairs of gears and laboratory experiments with simulation of pump operating conditions. The results and conclusions presented in this paper, with an emphasis on the actual work processes, bring very important perspectives for the gerotor pumps design with improved performance.


Author(s):  
S H Mok ◽  
D G Gorman

Maintenance of offshore drilling mud pumps is normally based on running hours. It is generally accepted, however, that time does not provide an accurate means of scheduling maintenance, given the varying operating conditions of the reciprocating mud pumps. The energy expended at the interaction of sliding surfaces is hypothesized to be a better alternative. The effects of operating variables on wear rates are investigated. A Taguchi experimental design was used to identify those factors that significantly affect wear. Within the confines of an experimental test rig, the normal load and abrasive sand content was found to have a significant effect on the specific wear rate of nitrile rubber sliding on steel in drilling fluid.


2007 ◽  
Vol 25 (11) ◽  
pp. 1867-1873 ◽  
Author(s):  
A. B. Bonafonte ◽  
O. Iglesias ◽  
J. L. Bueno

2019 ◽  
Vol 26 (01) ◽  
pp. 157-162
Author(s):  
Davaasuren G ◽  
Gantulga G

It is vitally important for vehicle users that are to study the operating regime that may negative effect to the operation of the engine, to reduce its effect, to maintain the engine's reliability in accordance with the specific operating conditions. Quality of lubrication is one of the main factors that are improving of reliability and operational efficiency for any machinery their spare parts. So this paper presents to optimize of oil change intervals and to determine of wear rating of spare parts by content of metal particles in the internal combustion engine used oil. Дотоод шаталтат хөдөлгүүрийн тос солих хугацааг оновчлох нь Хураангуй:  Машин ашиглагчдын хувьд тухайн хөдөлгүүрийн ажиллагаанд сөрөг нөлөө үзүүлэх  ашиглалтын горимыг судалж, түүний хор нөлөөг багасгах болон ашиглалтын өвөрмөц  нөхцөлд тохируулан хөдөлгүүрийн найдварт ажиллагааг ханган зөв, ашигтай ажиллуулах  чадвартай байх нь асар их ач холбогдолтой юм. Аливаа машин техник , тэдгээрийн агрегат,  зангилаа эд ангийн удаан эдлэхүй, найдвартай ажиллагааг хангах, ашиглалтын үр ашгийг  дээшлүүлэх гол хүчин зүйлүүдийн нэг нь тосолгооны чанар байдаг учраас дотоод шаталтат  хөдөлгүүрийн ашигласан тосон дахь металлын агууламжыг илрүүлж, эд ангийн элэгдлийн  явцыг тодорхойлон, тос солих хугацааг оновчлох асуудлыг судалгааны хүрээнд авч үзлээ.  Түлхүүр үг: Хөдөлгүүрийн ашигласан тосны шинжилгээ, металл хольц, тосны бохирдол,  тортог, элэгдлийн элементийн хязгаар 


2021 ◽  
Author(s):  
Wittawat Wulyapash ◽  
Awassada Phongphiphat ◽  
Sirintornthep Towprayoon

Abstract Large amounts of sludge are generated from wastewater treatment in seafood processing industries. Most of the dewatered sludge in Thailand is not utilized and disposed by landfilling. The dried sludge utilization as refuse-derived fuel (RDF) is an alternative solution due to the gross calorific value (GCV), which is greater than 21.9 MJ/kg. However, the key obstacle is its high moisture content of 87.4% (wet basis). Therefore, drying methods using hot air and microwave techniques were investigated for preparing dried sludge. The effects of hot air temperatures (100-150 °C) and microwave power levels (100-800 W) were compared on drying kinetics, specific energy consumption (SEC), and characteristics of the dried products. The results showed that drying times were decreased by increasing the hot air temperatures. In the same way, the increase in microwave power levels decreased the drying time. The application of microwaves contributed to reducing the drying time by more than 46% compared to the hot air. The reduction of drying times resulted in the saving SEC. The GCV of the dried sludge decreased with the decrease in the volatile matter (VM) due to the high component of VM as 79.5-80.3% (dry ash-free basis). The sludge dried by the microwaves showed a lower GCV than the hot air products. However, dried sludges still had high GCV (≥ 20.8 MJ/kg). Furthermore, the minimal variation of the product characteristics demonstrated that the microwave technique could be applied as an alternative drying method with a rapid process compared to the conventional hot air technique.


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