Evaluation of flowability for granulated powder using a test of powder discharge by pressurized air

This study experimentally and theoretically examined the flowability and the cohesiveness for powder using a test of powder discharge through an orifice by the pressurized air. The powder used consisted of two kinds of Calcium hydroxide which have different particle sizes by granulation. These sizes are 11µm and 176µm, those called Ca(OH)2 -A and -B. Cohesiveness is characterized by the Bond number which is the ratio of separation force to the gravity force. Flowability is evaluated by the relationship between the mass flow rate and the average air pressure acting on the powder bed. We found that the Bond number of Ca(OH)2 -B was much lower than Ca(OH)2 -A. The relation between the mass flow rate of the powder and the average air pressure indicates Ca(OH)2 -B is easily flowing at the lower pressure region, and Ca(OH)2 -A was scattered at the higher pressure region. This means Ca(OH)2 -B has good flowability by the particle granulation in comparison with Ca(OH)2 -A.

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Flow Field in the Tip Gap of a Planar Cascade of Turbine Blades

Journal of Turbomachinery ◽

10.1115/1.3262266 ◽

1989 ◽

Vol 111 (3) ◽

pp. 276-283 ◽

Cited By ~ 21

Author(s):

M. Yaras ◽

Yingkang Zhu ◽

S. A. Sjolander

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Pressure Difference ◽

Good Accuracy ◽

Flow Direction ◽

Turbine Blades ◽

Rate Distribution ◽

Velocity Magnitude ◽

The Relationship

Measurements are presented for the flow in the tip gap of a planar cascade of turbine blades. Three clearances of from 2.0 to 3.2 percent of the blade chord were considered. Detailed surveys of the velocity magnitude, flow direction, and total pressure within the gap were supplemented by blade surface and endwall static pressure measurements. The results help to clarify the relationship between the leakage mass flow rate distribution and the driving pressure differences. It was found that even for the present relatively large clearances, fluid near the endwall experiences a pressure difference that is comparable with the blade pressure difference. It is also shown that a simple model can predict with good accuracy the mass flow rate distribution and the magnitude and direction of the velocity vectors within the gap.

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Mass flow rate of fine and cohesive powders under differential air pressure

Powder Technology ◽

10.1016/j.powtec.2018.04.041 ◽

2018 ◽

Vol 334 ◽

pp. 173-182 ◽

Cited By ~ 6

Author(s):

R. Baserinia ◽

I.C. Sinka

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Air Pressure ◽

Cohesive Powders

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Development of ring-shaped electrostatic coupled capacitance sensor for the parameter measurement of gas-solid flow

Transactions of the Institute of Measurement and Control ◽

10.1177/01423312211006640 ◽

2021 ◽

pp. 014233122110066

Author(s):

Hui Ding ◽

Jian Li ◽

Haoran Wang ◽

Chuanlong Xu

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Correlation Coefficients ◽

Parameter Measurement ◽

Capacitance Sensor ◽

Temperature Drift ◽

Solid Flow ◽

The Relationship ◽

Source Electrode

This paper develops a novel non-intrusive ring-shaped electrostatic coupled capacitance sensor (ECCS) for the parameter measurement of gas-solid flow to eliminate the temperature drift of traditional capacitance sensor and to improve the reliability of velocity measurement. In ECCS, one source electrode and two detection electrodes are housed in a sensing head to simultaneously derive two pairs of capacitance and electrostatic signals, which can achieve the simultaneous measurement of the particle velocity, concentration and mass flow rate within the same sensing space of gas-solid flow system. The effects of the isolation electrodes on the capacitance sensitivity and the temperature drift of the sensor standing capacitance are further investigated. Then, a weighted velocity is determined by fusing the capacitance correlation velocity and the electrostatic correlation velocity based on the correlation coefficients, which are useful for the reliable measurement of gas-solid flow. Finally, experiments are carried out to test the performance of the developed ring-shaped ECCS. Results demonstrate that the developed ECCS triples the capacitance sensitivity for the radial position from -15 mm ∼15 mm. The temperature drift of the capacitance signal is less than 0.075 mV/oC from the room temperature to 65 oC, and thus the sensor standing capacitance is almost impervious to the temperature. After calibrating the relationship between the particle concentration and the capacitance signal, the developed ECCS can measure the particle mass flow rate with a relative error less than ±8%.

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Feedback linearization based air pressure and mass flow rate regulation for PEMFCs

2015 54th Annual Conference of the Society of Instrument and Control Engineers of Japan (SICE) ◽

10.1109/sice.2015.7285576 ◽

2015 ◽

Author(s):

Fang Chuan ◽

Xu Liangfei ◽

Li Jianqiu ◽

Ouyang Minggao

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Feedback Linearization ◽

Air Pressure ◽

Rate Regulation

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Extrusion Characteristics of Thin Walled Tubes for Catheters Using Thermoplastic Elastomer

Polymers ◽

10.3390/polym12081628 ◽

2020 ◽

Vol 12 (8) ◽

pp. 1628

Author(s):

Soonmo Cho ◽

Euntaek Lee ◽

Seunggi Jo ◽

Gyu Man Kim ◽

Woojin Kim

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Wall Thickness ◽

Flow Rate ◽

High Performance ◽

Thermoplastic Elastomer ◽

Air Pressure ◽

Outer Diameter ◽

Screw Speed ◽

Thin Walled

As the market for minimally invasive surgery has grown, the demand for high-precision and high-performance catheters has increased. Catheters for the diagnosis and treatment of cardiovascular or cerebrovascular disease mainly use a braided wire tube with a polymer inner liner and outer jacket to improve the pushability and trackability. The outer jacket should have an accurate inner and outer diameter and while maintaining a wall thickness of 150 µm or less. In this study, we designed and manufactured a tip and die capable of extruding an outer jacket with a wall thickness of 150 µm or less using a medical thermoplastic elastomer for manufacturing 8Fr (2.64 mm diameter) thin-walled tubes. The ovality and inner/outer diameters of the tube were studied according to changes in the screw speed (mass flow rate), puller speed, air pressure applied to the lumen, and distance between the quench and head, which are the main variables of microextrusion processes. The screw speed (mass flow rate), puller speed, and air pressure affected the inner/outer diameter of the tube, with screw speed and puller speed having the largest influence on diameter. The air pressure and distance between quench and head had the greatest influence on ovality. The results show the effect of different processing parameters on the characteristics of the extruded tube, which will help to establish a stable extrusion process for the manufacture of outer jackets for braided catheter shafts.

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