TY - JOUR
T1 - Magnetically mediated flow enhancement for controlled powder discharge of cohesive powders
AU - Dave, Rajesh N.
AU - Wu, Chang Yu
AU - Chaudhuri, Bodhisattwa
AU - Watano, Satoru
N1 - Funding Information:
Financial support from the New Jersey Commission on Science and Technology through the Grant No. 97-100-020-2890-051-6130 is gratefully acknowledged. The authors also wish to thank Mr. Sanjiv Patel and Mr. Mariusz Maziarz, Chemical Engineering Department, NJIT, for performing the experiments; Mr. William Dunphy, Mechanical Engineering Department, NJIT, for setting up the experimental system; Mr. Greg James, Mechanical Engineering Department, NJIT, for providing the angle of repose results; and Dr. Maher Moakher and Dr. Fernando Muzzio for providing an object-oriented version of the original code from Ref. [33] .
PY - 2000/10/5
Y1 - 2000/10/5
N2 - A new flow enhancement system is developed for cohesive powders. It is based on the concept of multiple, point source, internal excitations. In this system, a mass of small permanent-magnetic particles are placed in the discharge zone of a hopper, and then an oscillating magnetic field is applied to excite these magnets. A screen is placed at the exit to keep the magnets within the hopper. The magnetic particles spin furiously, go though random collisions with each other, and agitate the mass of cohesive powder near the exit of the hopper. As a result, the internal structure of the cohesive powder is disrupted and the powder gets fluidized and demonstrates an increased flowability. This device, called the magnetically assisted powder flow (MAPF) system, has been investigated for discharging cohesive powder from a hopper. It is shown that this device is capable of a controlled powder discharge, which is a linear function of time. The effects of various parameters, such as the amount and size of the magnetic particles and the magnetic field strength on the discharge rate are investigated. The operating principle of this device is different from conventional flow enhancement devices such as pneumatic, vibrational, or mechanical systems because powder 'fluidization' is generated through random motion of the magnetic particles within the powder, and the presence of the screen prevents flooding. Modeling of the motion of the magnetic particles under the influence of an oscillating field is considered to show how the spinning and random translations occur in such a system. Discrete element modeling of a system of magnetic particles is also carried out to show the effect of various parameters on fluidization. This system can be applied for other powder technology applications, for example, the measurement of angle of repose for cohesive powders. (C) 2000 Elsevier Science S.A.
AB - A new flow enhancement system is developed for cohesive powders. It is based on the concept of multiple, point source, internal excitations. In this system, a mass of small permanent-magnetic particles are placed in the discharge zone of a hopper, and then an oscillating magnetic field is applied to excite these magnets. A screen is placed at the exit to keep the magnets within the hopper. The magnetic particles spin furiously, go though random collisions with each other, and agitate the mass of cohesive powder near the exit of the hopper. As a result, the internal structure of the cohesive powder is disrupted and the powder gets fluidized and demonstrates an increased flowability. This device, called the magnetically assisted powder flow (MAPF) system, has been investigated for discharging cohesive powder from a hopper. It is shown that this device is capable of a controlled powder discharge, which is a linear function of time. The effects of various parameters, such as the amount and size of the magnetic particles and the magnetic field strength on the discharge rate are investigated. The operating principle of this device is different from conventional flow enhancement devices such as pneumatic, vibrational, or mechanical systems because powder 'fluidization' is generated through random motion of the magnetic particles within the powder, and the presence of the screen prevents flooding. Modeling of the motion of the magnetic particles under the influence of an oscillating field is considered to show how the spinning and random translations occur in such a system. Discrete element modeling of a system of magnetic particles is also carried out to show the effect of various parameters on fluidization. This system can be applied for other powder technology applications, for example, the measurement of angle of repose for cohesive powders. (C) 2000 Elsevier Science S.A.
KW - Angle of repose
KW - Discrete element simulations
KW - Hopper flow enhancements
KW - Magnetic fluidization
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U2 - 10.1016/S0032-5910(99)00312-5
DO - 10.1016/S0032-5910(99)00312-5
M3 - Article
AN - SCOPUS:0034610117
SN - 0032-5910
VL - 112
SP - 111
EP - 125
JO - Powder Technology
JF - Powder Technology
IS - 1-2
ER -