The effect of microtexture on the liquid flow over the sheets

This work considers the method of the corrugated sheet arrangement near the column wall with the aim to limit liquid fall on the wall and increase liquid concentration in the near-wall area. Experiments were carried out at the corrugated Koch 1Y packing sheets for various liquid flow rates. This report presents experimental results on the character of liquid flow near the edge of corrugated sheets and the effect of the middle sheet shift from the edge of the packing. The ribs of this sheet are directed downward to the edge of the packing. Test was performed for two positions of the middle sheet: to study the effect of microtexture orientation at the sheet, whose ribs are directed downward to the packing edge, on liquid distribution under the packing. Experiments were carried out for liquid flow rates of 1-12 ml/s.

Downward Annular Flow of Air–Oil–Water Mixture in a Vertical Pipe

The paper presents the results of a study concerned with the hydrodynamics of an annular downward multiphase flow of gas and two mutually non-mixing liquids through a vertical pipe with a diameter of 12.5 mm. The air, oil and water were used as working media in this study with changes in superficial velocities in the ranges of jg = 0.34–52.5 m/s for air, jo = 0.000165–0.75 m/s for oil, and jw = 0.02–2.5 m/s for water, respectively. The oil density and viscosity were varied within the ranges of ρo = 859–881 kg/m3 and ηo = 29–2190 mPas, respectively. The research involved the identification of multiphase flow patterns and determination of the void fraction of the individual phases. New flow patterns have been identified and described for the gravitational flow conditions of a two-phase water–oil liquid and a three-phase air–water–oil flow. New flow regime maps and equations for the calculation of air, oil and water void fractions have been developed. A good conformity between the calculated and measured values of void fraction were obtained. The map for the oil–water–air three-phase flow is valid for the following conditions: j3P = 0.35–53.4 m/s (velocity of three-phase mixture) and oil in liquid concentration βo* = 0.48–94% (oil in liquid concentration). In the case of a downward annular oil–water two-phase flow, this map is valid for liquid mixture velocity jl = 0.052–2.14 m/s and βo* = 0.48–94%.

A New Approach to Determining Liquid Concentration Using Multiband Annular Ring Microwave Sensor and Polarity Correlator

This article presents a new approach to determining liquid concentration using a new microwave sensor and polarity correlator. The sensor design incorporates an annular ring resonator having inside three parallel lines, a trapezoid ground plane and a co-planar waveguide (CPW) tapered feeder, which altogether achieve multiple frequency bands. Multiple bands of interest are obtained at the lower end of the microwave spectrum, i.e., from 1–6 GHz, as this region is widely accepted in analyzing various liquid samples. The sensor size is 71 × 40 × 1.6 mm3 with material selection based on an economically available FR4 substrate. The sensor is realized and experimentally validated for its sensitivity by utilizing in-lab prepared aqueous solution samples. Further, liquid concentration is determined by adopting a polarity correlator, which is applied to the sensor’s responses obtained at different values.

Study on the formation and separation process of droplets in the medical piezoelectric atomization device induced by intra-hole fluctuation

Oral inhalation of aerosolized drugs can be directly performed on the affected body organs including lesions of the throat, trachea as well as lungs. As compared to the other conventional therapies such as intravenous drip, intramuscular injection and external topical administration, this novel technique can greatly reduce the dosage and side effects of drugs. However, the traditional atomization devices always exhibit many drawbacks, such as wide spreading distribution of atomization particle size, the instability of transient atomization quantity and difficulties in precise energy control, which seriously restrict more extensive application of atomization inhalation therapy. The formation and separation process of droplets is a microphenomenon of atomization. Research on the droplet formation and separation process will help us to better understand the atomization mechanism. In present work, the Conservative Level Set Method (CLSM) is the first time to be applied on the simulation of the formation and separation of droplets in a medical piezoelectric atomization device induced by intra-hole fluctuation. The intra-hole fluctuation mechanism is analyzed in details, and also the expression of the volume change of the micro cone hole is evaluated. The control equation and simulation model of droplet formation and separation process has been well established by meshing the simulation model, and thereby the process of droplet formation and separation is simulated. The corresponding results demonstrate that the breaking time of droplets decreases with the increase of inlet velocity and liquid temperature, and increases with the increase of liquid concentration. Meanwhile, the volume of droplet decreases with the increase of inlet velocity and liquid concentration, but increases with the increase of liquid temperature. The velocity of droplet is enhanced with the inlet velocity and liquid temperature rising, and reduced with the increase of liquid concentration. When the large side diameter of micro-cone hole is set as 79 μm, the breaking time of the droplet reaches a minimum value of 38.7 μs, whereas the volume and the velocity of droplet reaches a maximum value of 79.8 pL and 4.46m/s, respectively. This study reveals the atomization mechanism of the medical piezoelectric atomization device induced by intra-hole fluctuation from a micro perspective . It provides theoretical guidance for the design of medical piezoelectric atomization devices and contributes to the promotion of inhalation therapy in practical use.