Uneven distribution of particle flow in RFCC reactor riser

Cho, Hyungtae,Kim, Junghwan,Park, Chanho,Lee, Kwanghee,Kim, Myungjun,Moon, Il Elsevier Sequoia 2017 Powder technology Vol.312 No.-

<P><B>Abstract</B></P> <P>The uneven distribution of particle flow, i.e., a different particle mass flow rate in each outlet of the riser in residue fluidized catalytic cracking (RFCC) processes, is one major problem associated with commercial RFCC processes. This problem affects the formation of carbonaceous deposits in the secondary reactor cyclone, which incurs serious catalyst carryover in the fractionators. This study analyzes particle-fluid flow patterns in the riser, and diagnoses the uneven distribution of particle flow using a computational particle fluid dynamics (CPFD) method to solve this real industrial problem. Through this analysis, the effect of the number of feed injectors is investigated. The CPFD method, which has been developed to complement the Eulerian-Eulerian and Eulerian-Lagrangian methods, applies the Navier-Stokes equation for fluid phase and multi-phase-particle-in-cell (MP-PIC) models for particle phase. The particle flow distribution was found to vary by 15.5–18.7% at different outlets in the 1 injector case, which implies that the solid loading ratio in each cyclone is different, thereby affecting the separation efficiency of the cyclone and the formation of carbonaceous deposits. The uneven distribution of particle flow phenomena was identified, and the standard deviations of particle mass flow rates were evaluated for the cases of 1, 2, 4, 6, 8 and 12 injectors, and were found to be 7.52, 4.07, 2.66, 1.78, 2.85 and 3.82, respectively. From these results, the 6 injectors case was found to have a largely even particle flow distribution.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We develop CPFD model of the riser of RFCC under commercial operation conditions. </LI> <LI> This CPFD model was verified by comparing it with the commercial plant data. </LI> <LI> The uneven distribution of particle flow affecting a turnaround period is ascertained. </LI> <LI> We solve the industrial problem by investigating the effect of the feed injector. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

EFFECT OF TIME AFTER FEEDING ON DISTRIBUTION OF FEED PARTICLES IN THE GASTROINTESTINAL TRACT OF SHEEP GIVEN ORCHADGRASS HAY ONCE A DAY

Sekine, J.,Imaki, Y.,Kuninishi, Y.,Oura, R.,Miyazaki, H.,Okamoto, M.,Asahida, Y. Asian Australasian Association of Animal Productio 1992 Animal Bioscience Vol.5 No.1

To determine the effect of time after feeding on distribution of particle size of digesta in the gastrointestinal tract, 16 sheep given orchardgrass first cut hay were slaughtered at 2, 8, 16 and 24 hours after feeding and digesta in diverse sites of the tract were sieved into four fractions of particle size larger than $1180{\mu}m$, 300-1180, 45-300 and less than 45. Following results were obtained: 1) In the reticulo-rumen, the proportion of particles larger than $1180{\mu}m$ decreased with the time after feeding, while the other particle size fractions did not change with time after feeding. 2) In the post-ruminal alimentary tract, the proportion of particles larger than $1180{\mu}m$ was significantly smaller than that in the reticulo-rumen and distribution of fractions of every particle size stayed consistently at about the same level irrespective of the time after feeding. 3) In the cecum, the fraction of particle size less than $45{\mu}m$ appeared to be selectively retained when the passage rate was considered.

Size and morphology manipulation of nickel nanoparticle in inductively coupled thermal plasma synthesis

Kim, Y.M.,Kim, K.H.,Kim, B.,Choi, H. Elsevier Sequoia 2016 JOURNAL OF ALLOYS AND COMPOUNDS Vol.658 No.-

Nickel nanoparticles for the internal electrode of multi-layer ceramic capacitors have been persistently developed in response to the industrial requirements for volumetric capacitance increases. In this context, the manipulation of particle size and morphology is still critical. In the present study, Ni nanoparticles were synthesized by feeding Ni(OH)<SUB>2</SUB> micro-powder feedstock into argon-hydrogen thermal plasma. The injected micro-powder feedstock was fully vaporized and reduced, owing to the high energy density and reactivity of thermal plasma. In association with particle size and morphology, the mass feed-rate and quenching gas were chosen as the variables affecting condensation behaviors from the viewpoint of characteristic times in a general collision-coalescence model. Particle size and morphology varied significantly from well-dispersed coarse nanoparticles to aggregates of fine primary nanoparticles, according to the process parameters. The process parameters' effects on the synthesized nanoparticle properties were considered. In addition, spherical nanoparticles with internal band-like sub-structures were frequent, particularly for coarse particles. From the transmission electron microscopy study and molecular dynamic simulation, it was proven that the band-like sub-structure is nano-twin, and the twin boundary is stabilized by the spontaneous rotating of colliding particles.

Effects of feed form and particle size on growth performance, nutrient digestibility, carcass characteristics, and gastric health in growing-finishing pigs

Jo Yun Yeong,Choi Myung Jae,Chung Woo Lim,Hong Jin Su,Lim Jong Seon,김유용 아세아·태평양축산학회 2021 Animal Bioscience Vol.34 No.6

Objective: This study was conducted to evaluate the effects of feed processing and particle size on growth performance, nutrient digestibility, carcass characteristics, and gastric health in growing-finishing pigs. Methods: A total of 360 growing pigs (22.64±0.014 kg initial body weight [BW]) were allocated to 1 of 6 treatments with 6 replicates by BW and sex, and 10 pigs were housed in one pen in a randomized complete block design. The BW and feed intake were recorded to calculate growth performance. For the digestibility trial, a total of 24 barrows with an initial BW of 33.65±0.372 kg were split into 6 treatments with a completely randomized design. Dietary treatments were designed by a 2×3 factorial arrangement of treatments based on two main factors, particle size (600, 750, 900 μm) and feed form (mash and pellet) of diet. Experimental diets were formulated to contain the requirements of the NRC (2012). Results: The BW and average daily gain were not changed by dietary treatments, and the feed intake of finishing pigs (wks 6 to 12) was increased when the pigs were fed a mash diet (p<0.05). For the overall period, the feed efficiency of pigs was improved with the pellet diet (p<0.01) and reduced particle size (p<0.05). The pellet diet had effects on increasing crude fat digestibility (p<0.01) relative to a mash diet, but there was no considerable change in dry matter and crude protein digestibilities by dietary treatments. In the evaluation of gastric health, a trend for an increased incidence of keratinization in the esophageal region was observed as particle size decreased (p = 0.07). Conclusion: Feed efficiency could be improved by pellet diet and reduced particle size. Nutrient digestibility, carcass characteristics, and gastric health were not affected by feed form, and particle size ranged from 600 to 900 μm. Objective: This study was conducted to evaluate the effects of feed processing and particle size on growth performance, nutrient digestibility, carcass characteristics, and gastric health in growing-finishing pigs.Methods: A total of 360 growing pigs (22.64±0.014 kg initial body weight [BW]) were allocated to 1 of 6 treatments with 6 replicates by BW and sex, and 10 pigs were housed in one pen in a randomized complete block design. The BW and feed intake were recorded to calculate growth performance. For the digestibility trial, a total of 24 barrows with an initial BW of 33.65±0.372 kg were split into 6 treatments with a completely randomized design. Dietary treatments were designed by a 2×3 factorial arrangement of treatments based on two main factors, particle size (600, 750, 900 μm) and feed form (mash and pellet) of diet. Experimental diets were formulated to contain the requirements of the NRC (2012).Results: The BW and average daily gain were not changed by dietary treatments, and the feed intake of finishing pigs (wks 6 to 12) was increased when the pigs were fed a mash diet (p<0.05). For the overall period, the feed efficiency of pigs was improved with the pellet diet (p<0.01) and reduced particle size (p<0.05). The pellet diet had effects on increasing crude fat digestibility (p<0.01) relative to a mash diet, but there was no considerable change in dry matter and crude protein digestibilities by dietary treatments. In the evaluation of gastric health, a trend for an increased incidence of keratinization in the esophageal region was observed as particle size decreased (p = 0.07).Conclusion: Feed efficiency could be improved by pellet diet and reduced particle size. Nutrient digestibility, carcass characteristics, and gastric health were not affected by feed form, and particle size ranged from 600 to 900 μm.

Effects of Feed Particle Size and Feed Form on Growth Performance, Nutrient Metabolizability and Intestinal Morphology in Broiler Chickens

Zang, J.J.,Piao, X.S.,Huang, D.S.,Wang, J.J.,Ma, X.,Ma, Yongxi Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.1

This study was conducted to investigate the effect of feed particle size and feed form on growth performance, nutrient metabolizability and intestinal morphology in broiler chickens. This experiment was a 2${\times}$2 factorial arrangement including two feed particle sizes (fine and coarse) and two feed forms (mash and pellet). A total of two hundred and eighty eight day-old male Arbor Acre broilers were used in this six week experiment. Birds were randomly allotted to four dietary treatments with six replicates per treatment and twelve birds per replicate. The results showed that pelleting diets resulted in greater ADG (p<0.01), greater ADFI (p<0.01) and lower feed to gain ratio (F/G) (p<0.05) during starter, grower and overall period. Also, pelleting improved both apparent metabolizable energy (AME) (p<0.01) and the apparent metabolizability of crude protein (p<0.05) and organic matter (p<0.05) regardless of the phase. Reduction of feed particle size enhanced AME (p<0.05) during d 19 to 21. Increased villus height (p<0.05) and crypt depth ratio (p< 0.05) within duodenum, jejunum, and ileum were observed in birds fed the pellet diet compared with those given the mash diet. In conclusion, results indicated that feed pellets might enhance performance by improving nutrient metabolizability and digestive tract development.

배합사료의 크기, 사육밀도 및 용존산소 농도가 넙치 (Paralichthys olivaceus)의 성장에 미치는 영향

김성삼 ( Sung Sam Kim ),이진혁 ( Jin Hyuck Lee ),김강웅 ( Kang Woong Kim ),김경덕 ( Kyoung Duck Kim ),이봉주 ( Bong Joo Lee ),이경준 ( Kyeong Jun Lee ) 한국수산과학회 2015 한국수산과학회지 Vol.48 No.3

We performed three sets of feeding trials to establish the optimal feed size (Exp-I), stocking density (Exp-II), and dis-solved oxygen level (DO) (Exp-III) for olive flounder Paralichthys olivaceus. In Exp-1, four replicate groups of fish (53.6±0.9 g) were fed commercial diets with three particle sizes (small, medium, and large). In Exp-II, fish (30.0±0.1 g) were reared at four stocking densities (1.8, 3.5, 5.3, and 7.1 kg/m3). In Exp-III, fish (187±1.48 g) were reared under two different DO levels (2-3 and 6-7 mg/L). In Exp-I, fish fed the large-particle diet gained significantly more weight and had a lower feed conversion ratio than fish fed the small- and medium-particle diets. In Exp-II, fish reared at 1.8 and 3.5 kg/m3 gained slightly more weight and had lower feed conversion ratios than fish reared at 5.3 and 7.1 kg/m3, although these differences were not significant. In Exp-III, negative effects were observed in the low DO groups. Therefore, under our experimental conditions, the optimal feed particle size, stocking density, and DO level for olive flounder were 9-9.4 mm, 3.5 kg/m3, and 6-7 mg/L, respectively.

Effects of Three Feeding Systems on Production Performance, Rumen Fermentation and Rumen Digesta Particle Structure of Beef Cattle

Liu, Y.F.,Sun, F.F.,Wan, F.C.,Zhao, H.B.,Liu, X.M.,You, W.,Cheng, H.J.,Liu, G.F.,Tan, X.W.,Song, E.L. Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.5

The effects of three different feeding systems on beef cattle production performance, rumen fermentation, and rumen digesta particle structure were investigated by using 18 Limousin (steers) with a similar body weight ($575{\pm}10kg$) in a 80-d experiment. The animals were equally and randomly divided into three treatment groups, namely, total mixed ration group (cattle fed TMR), SI1 group (cattle fed concentrate firstly then roughage), and SI2 group (cattle fed roughage firstly then concentrate). The results showed that the average daily gain was significantly higher in cattle receiving TMR than in those receiving SI1 and SI2 (p<0.05). Consumption per kg weight gain of concentrate, silage, and combined net energy (NEmf) were significantly decreased when cattle received TMR, unlike when they received SI1 and SI2 (p<0.05), indicating that the feed efficiency of TMR was the highest. Blood urea nitrogen (BUN) was significantly decreased when cattle received TMR compared with that in cattle receiving SI1 (p<0.05), whereas there was no difference compared with that in cattle receiving SI2. Ammonia nitrogen concentration was significantly lower in cattle receiving TMR than in those receiving SI1 and SI2 (p<0.05). The rumen area of cattle that received TMR was significantly larger than that of cattle receiving SI1 (p<0.05), but there was no difference compared with that of cattle receiving SI2. Although there was no significant difference among the three feeding systems in rumen digesta particle distribution, the TMR group trended to have fewer large- and medium-sized particles and more small-sized particles than those in the SI1 and SI2 groups. In conclusion, cattle with dietary TMR showed increased weight gain and ruminal development and decreased BUN. This indicated that TMR feeding was more conducive toward improving the production performance and rumen fermentation of beef cattle.

돼지 생산성에 있어 게르마늄흑운모의 첨가수준 및 입자도의 효과

이원백,김인호,홍종욱,권오석,민병준,손경승,정연권 한국동물자원과학회 2003 한국축산학회지 Vol.45 No.5

Two experiments were conducted to investigate the effect of germanium biotite (GB) on growth performance, nutrient digestibility and fecal gas emission in pigs. In Exp 1., a total of one hundred nursery pigs (initial body weight 13.12 ± 0.15㎏) were used in a 21 d growth assay. The five treatments were control (CON, basal diet), GB0.5-200(basal diet + 0.5% GB, 200mesh), GB1.0-200 (basal diet + 1.0% GB, 200mesh), GB0.5-325 (basal diet + 0.5% GB, 325mesh), GB1.0-325 (basal diet + 1.0% GB, 325mesh). Each treatment had four replicates with five pigs per replicate. ADG, ADFI ad gain/feed were not significantly different among the treatments. Fecal NH_(3)-N concentration of pigs fed the GB325 diet was lower than that of pigs fed the GB200 diet (P=0.01). The GB treatments reduced fecal volatile fatty acids significantly compared to the CON (propionic acid, P=0.01;butyric acid, P=0.01; acetic acid, P=0.02). Especially, fecal propionic acid concentration of pigs fed the GB325 diets was lower than that of pigs fed the GB200 diets (P=0.02). In Exp 2., a total of seventy five pigs (initial body weight 21.18 ± .15㎏) were used in a 28 d growth assay. The treatments were same as described for Exp. 1. Each treatment had five replicates with three pigs per replicate. The GB1.0 treatments significantly increased the ADG compared to the GG0.5 treatments (P=0.03). The DM and N digestibility of pigs fed the GB1.0 diets were higher than that for pigs fed the GB0.5 diets (p=0.01). Also, the Ca digestibility of pigs fed the GB diets than that for pigs fed the GB0.5 diets (p=0.01). The fecal NH_(3)-N concentrations for the GB treatments were lower than that for the CON (P=0.01). The GE325 tratments significantly decreased the fecal NH_(3)-N concentration compared to the GB200 treatments (P=0.03). the fecal butyric acid concentration for the GB325 treatments was lower than that for the GB200 treatment (P=0.04). In conclusion, the results obtained from these feeding trials suggest that the dietary GB for nursery pigs affects fecal noxious gas emission. In growing pigs, dietary GB was effective to improve ADG and decrease fecal noxious gas emission.

분체시료 입도 변화에 따른 고압 주입장치 운전특성 시험 결과

윤성필(Sung Pill Yun),정기진(Ki Jin Jung),권인구(In Goo Kwon),정석우(Seok Woo Chung) 한국에너지기후변화학회 2018 한국에너지기후변화학회 학술대회 Vol.2018 No.11

Synthesis of highly carboxylated latex particles using a power feed process

R. Santilla´n,M. Corea,E. Nieves,C.P. Alejandre,C. Gomez-Yanez,J.M. del Rı´o,H. Dorantes-Rosales,M.E. Navarro-Clemente 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.4

Two series of highly carboxylated latex particles were synthesized via a power feed process. The concentration carboxylic groups were varied inside the particles and a gradient in the concentration from the interior to the surface was created. The power feed process, proposed by Bassett et al., was used for the synthesis of the functionalized materials and a mathematical model was proposed for this process and theoretical predictions for the concentration of carboxylic groups inside the particles were corroborated with experimental results. A methodology based on thermodynamic formalism is proposed to study the response of these materials to ion exchange.