149 Evaluation of Hammermill Tip Speed, Air Assist, and Screen Hole Diameter on Ground Corn Characteristics

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 134-135
Author(s):  
Michaela B Braun ◽  
Kara M Dunmire ◽  
Michael Sodak ◽  
Jerry Shepherd ◽  
Randy Fisher ◽  
...  

Abstract This study was performed to evaluate hammermill tip speed, assistive airflow and screen hole diameter on hammermill throughput and characteristics of ground corn. Corn was ground using two Andritz hammermills (Model: 4330–6, Andritz Feed & Biofuel, Muncy,PA) measuring 1-m in diameter each equipped with 72 hammers and 300 HP motors. Treatments were arranged in a 3 × 3 × 3 factorial design with 3 tip speeds (3,774, 4,975, and 6,176 m/min), 3 screen hole diameters (2.3, 3.9 and 6.3 mm), and 3 air flow rates (1,062, 1,416, and 1,770 fan RPM). Corn was ground on 3 separate days to create 3 replications and treatments were randomized within day. Samples were collected and analyzed for moisture, particle size, and flowability characteristics. Data were analyzed using the GLIMMIX procedure of SAS 9.4 with grinding run serving as the experimental unit and day serving as the block. There was a 3-way interaction for standard deviation (Sgw), (linear screen hole diameter × linear hammer tip speed × linear air flow, P = 0.029). There was a screen hole diameter × hammer tip speed interaction (P < 0.001) for geometric mean particle size dgw (P < 0.001) and composite flow index (CFI) (P < 0.001). When tip speed increased from 3,774 to 6,176 m/min the rate of decrease in dgw was greater as screen hole diameter increased from 2.3 to 6.3 mm resulting in a 67, 111, and 254 µm decrease in dgw for corn ground using the 2.3, 3.9, and 6.3 mm screen hole diameter, respectively. For CFI, increasing tip speed decreased the CFI of ground corn when ground using the 3.9 and 6.3 mm screen. However, when grinding corn using the 2.3 mm screen, there was no evidence of difference in CFI when increasing tip speed. In conclusion, the air flow rate did not influence dgw of corn but hammer tip speed and screen size were altered and achieved a range of dgw from 304 to 617 µm.

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1768
Author(s):  
Michaela Braun ◽  
Haley Wecker ◽  
Kara Dunmire ◽  
Caitlin Evans ◽  
Michael W. Sodak ◽  
...  

This study was performed to evaluate hammermill tip speed, assistive airflow, and screen hole diameter on hammermill throughput and characteristics of ground corn. Corn was ground using two Andritz hammermills measuring 1 m in diameter each equipped with 72 hammers and 300 HP motors. Treatments were arranged in a 3 × 3 × 3 factorial design with three tip speeds (3774, 4975, and 6176 m/min), three screen hole diameters (2.3, 3.9, and 6.3 mm), and three air flow rates (1062, 1416, and 1770 fan revolutions per minute). Corn was ground on three separate days to create three replications and treatments were randomized within day. Samples were collected and analyzed for moisture, particle size, and flowability characteristics. There was a 3-way interaction (p = 0.029) for standard deviation (Sgw). There was a screen hole diameter × hammer tip speed interaction (p < 0.001) for geometric mean particle size dgw (p < 0.001) and composite flow index (CFI) (p < 0.001). When tip speed increased from 3774 to 6176 m/min, the rate of decrease in dgw was greater as screen hole diameter increased from 2.3 to 6.3 mm. For CFI, increasing tip speed decreased the CFI of ground corn when ground using the 3.9 and 6.3 mm screen. However, when grinding corn using the 2.3 mm screen, there was no evidence of difference in CFI when increasing tip speed. In conclusion, the air flow rate did not influence dgw of corn, but hammer tip speed and screen size were altered and achieved a range of dgw from 304 to 617 µm.


1984 ◽  
Vol 19 (1) ◽  
pp. 87-100
Author(s):  
D. Prasad ◽  
J.G. Henry ◽  
P. Elefsiniotis

Abstract Laboratory studies were conducted to demonstrate the effectiveness of diffused aeration for the removal of ammonia from the effluent of an anaerobic filter treating leachate. The effects of pH, temperature and air flow on the process were studied. The coefficient of desorption of ammonia, KD for the anaerobic filter effluent (TKN 75 mg/L with NH3-N 88%) was determined at pH values of 9, 10 and 11, temperatures of 10, 15, 20, 30 and 35°C, and air flow rates of 50, 120, and 190 cm3/sec/L. Results indicated that nitrogen removal from the effluent of anaerobic filters by ammonia desorption was feasible. Removals exceeding 90% were obtained with 8 hours aeration at pH of 10, a temperature of 20°C, and an air flow rate of 190 cm3/sec/L. Ammonia desorption coefficients, KD, determined at other temperatures and air flow rates can be used to predict ammonia removals under a wide range of operating conditions.


Author(s):  
Ari Kettunen ◽  
Timo Hyppa¨nen ◽  
Ari-Pekka Kirkinen ◽  
Esa Maikkola

The main objective of this study was to investigate the load change capability and effect of the individual control variables, such as fuel, primary air and secondary air flow rates, on the dynamics of large-scale CFB boilers. The dynamics of the CFB process were examined by dynamic process tests and by simulation studies. A multi-faceted set of transient process tests were performed at a commercial 235 MWe CFB unit. Fuel reactivity and interaction between gas flow rates, solid concentration profiles and heat transfer were studied by step changes of the following controllable variables: fuel feed rate, primary air flow rate, secondary air flow rate and primary to secondary air flow ratio. Load change performance was tested using two different types of tests: open and closed loop load changes. A tailored dynamic simulator for the CFB boiler was built and fine-tuned by determining the model parameters and by validating the models of each process component against measured process data of the transient test program. The know-how about the boiler dynamics obtained from the model analysis and the developed CFB simulator were utilized in designing the control systems of three new 262 MWe CFB units, which are now under construction. Further, the simulator was applied for the control system development and transient analysis of the supercritical OTU CFB boiler.


Author(s):  
M. Saensukjaroenphon ◽  
C. E. Evans ◽  
K. H. Sheldon ◽  
C. K. Jones ◽  
C. B. Paulk ◽  
...  

2020 ◽  
Vol 124 (1278) ◽  
pp. 1170-1189
Author(s):  
C. Cai ◽  
L. Guo ◽  
J. Liu

ABSTRACTThe gas temperature of the supersonic heat airflow simulated test system is mainly determined by the fuel and air flow rates which enter the system combustor. In order to realise a high-quality control of gas temperature, in addition to maintaining the optimum ratio of fuel and air flow rates, the dynamic characteristics of them in the combustion process are also required to be synchronised. Aiming at the coordinated control problem of fuel and air flow rates, the mathematical models of fuel and air supply subsystems are established, and the characteristics of the systems are analysed. According to the characteristics of the systems and the requirements of coordinated control, a fuzzy-PI cross-coupling coordinated control strategy based on neural sliding mode predictive control is proposed. On this basis, the proposed control algorithm is simulated and experimentally studied. The results show that the proposed control algorithm has good control performance. It cannot only realise the accurate control of fuel flow rate and air flow rate, but also realise the coordinated control of the two.


2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 701-701
Author(s):  
J. P. Goeser ◽  
B. Beck ◽  
T. Koehler ◽  
D. Tanata ◽  
E. Reid ◽  
...  

2017 ◽  
Vol 33 (6) ◽  
pp. 927-932
Author(s):  
Julie R Kalivoda ◽  
Cassandra K Jones ◽  
Charles R Stark

Abstract. Particle size reduction is an important component of feed manufacturing that impacts pellet quality, feed flowability, and animal performance. However, reducing particle size too fine often results in reduced flowability of the ground corn and finished feed, which creates potential handling and storage concerns at the feed mill and farm. The objective of this experiment was to determine how fractionation affected flowability of ground corn. Whole corn was received from a single source and ground to achieve 3 target particle sizes, 400, 500, and 600 µm with actual results of 469, 560, and 614 µm. Each target particle size was fractionated into three segments: fine (&lt; 282 µm), medium (&gt; 282 µm and &lt; 630 µm), and coarse (&gt; 630 µm) particles using a vibratory separator (model LS18SP3, SWECO, Florence, Ky.). Within particle size treatment, the percentage of sample obtained for each fraction was: 400 µm: 4.9%, 34.2%, and 60.9% for fine, medium, and coarse, respectively; 500 µm: 1.9%, 31.3%, and 66.9% for fine, medium, and coarse, respectively; and 600 µm: 1.0%, 24.4%, and 74.7% for fine, medium, and coarse, respectively. When the fractions were separated, their particle sizes were: 400 µm: 94, 269, and 744 µm for fine, medium, and coarse, respectively; 500 µm: 96, 253, and 815 µm for fine, medium, and coarse, respectively; and 600 µm: 99, 220, and 898 µm for fine, medium, and coarse, respectively. Fractionated samples were analyzed for multiple flowability characteristics, including: angle of repose, critical orifice diameter, composite flow index (CFI), bulk density, and compressibility. Treatments were arranged in a nested model with three replicates per treatment. Data were analyzed using the GLIMMIX procedure of SAS. When fraction was nested within particle size for each treatment, the fine fraction (&lt; 282 µm) of the 400 µm corn had the poorest CFI (P &lt; 0.05). Whereas the coarse fraction (&gt; 630 µm) of the 600 µm corn had the best CFI. The nutrient content of the fractions was greatest in the medium fraction (&gt; 282 µm and &lt; 630 µm) for crude protein, fat, and acid detergent fiber (ADF). In conclusion, reducing particle size resulted in the ground corn having poorer flowability characteristics, caused predominantly by particles that passed through a 282 µm screen. Based on this data, producers may potentially grind corn to a lower particle size while maintaining flowability if fine particles (&lt; 282 µm) are removed. Keywords: Corn, Flowability, Particle size analysis


Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1372
Author(s):  
Michaela Braun ◽  
Kara Dunmire ◽  
Caitlin Evans ◽  
Charles Stark ◽  
Jason Woodworth ◽  
...  

The objective of this study was to determine the effects of whole-corn moisture and hammermill screen size on subsequent ground corn moisture, particle size and flowability. Treatments were arranged as a 2 × 2 factorial design with two moisture concentrations (14.5 and 16.7%), each ground using 2 hammermill screen sizes (3 mm and 6 mm). Corn was ground using a lab-scale 1.5 HP Bliss Hammermill at three separate timepoints to create three replications per treatment. Ground corn flowability was calculated using angle of repose (AOR), percent compressibility, and critical orifice diameter (COD) measurements to determine the composite flow index (CFI). There was no evidence for a screen size × corn moisture interaction for ground corn moisture content (MC), particle size, standard deviation, or flowability metrics. Grinding corn using a 3 mm screen resulted in decreased (p < 0.041) moisture content compared to corn ground using the 6 mm screen. There was a decrease (p < 0.031) in particle size from the 6 mm screen to the 3 mm, but no evidence of difference was observed for the standard deviation. There was a decrease (p < 0.030) in percent compressibility as screen size increased from 3 mm to 6 mm. Angle of repose tended to decrease (p < 0.056) when corn was ground using a 6 mm screen compared to a 3 mm screen. For the main effects of MC, 16.7% moisture corn had increased (p < 0.001) ground corn MC compared to 14.5%. The 14.5% moisture corn resulted in decreased (p < 0.050) particle size and an increased standard deviation compared to the 16.7% moisture corn. The increased MC of corn increased (p < 0.038) CFI and tended to decrease (p < 0.050) AOR and COD. In conclusion, decreasing hammermill screen size increased moisture loss by 0.55%, decreased corn particle size by 126 µm and resulted in poorer flowability as measured by percent compressibility and AOR. The higher moisture corn increased subsequent particle size by 89 µm and had improved flowability as measured by CFI.


Author(s):  
А. Volnenko ◽  
◽  
А. Leudanski ◽  
Y. Apimakh ◽  
B. Korganbayev ◽  
...  

For separation of plastic wastes (polyamide (PA), acrylonitrile butadiene styrene (ABS) and polystyrene (PS), a flotation method is proposed. Using this method, the effect of concentration of surface-active substances (surfactants), which were used as polidocanol, sulphanole and a mixture of surfactants containing sodium laureth sulfate and diethanolamide, was studied. The research results analysis of the flotation separation of a mixture of crushed plastic wastes was carried out according to the calculated values of the extraction of a floated component ε and the purity of a concentrate β. It was noted that the maximum extraction of the floated component depends on the polymer and surfactant type. A mixture of surfactants at lower concentrations allows to achieve greater extraction of the floated component with less foaming ability. The research results on the extraction of polystyrene from the air flow rate at various concentrations of surfactants’ mixture show that the extraction has a maximum at a certain air flow rate. At low air flow rates, the working volume of liquid is not saturated enough with gas bubbles. If the optimal value of air flow rates is exceeded, many gas bubbles are formed that are not involved in the flotation process. The research results on the extraction of polystyrene from the aerated liquid layer height at various concentrations of surfactants’ mixture show that, at a low height of the aerated liquid layer, the probability of collision of a plastic particle with an air bubble is low and some potentially floated particles seek the bottom of an apparatus without having time to collide with an air bubble. When assessing the influence of liquid temperature on the flotation process, it was found that increasing the liquid temperature above 20°C leads to a sharp decrease in ABS and PS extraction. This is explained by the fact that the dependence of the surfactants’ foaming ability on the temperature is characterized by solubility curves and for most surfactants they have an extremum.


Sign in / Sign up

Export Citation Format

Share Document