Magdalena Matuszak

The effect of shear and extensional viscosity on atomization in medical inhaler.

The paper contains the results of experimental studies of water, aqueous solutions of glycerol and aqueous solutions of glycerol-polyethylene oxide (PEO) atomization process in a medical inhaler obtained by the use of the digital microphotography method. The effect of the shear and extensional viscosity on the drop size, drop size histogram and mean drop diameter has been analyzed. The obtained results have shown that the drop size increases with the increase in shear and extensional viscosity of liquid atomized. Extensional viscosity has a greater impact on the spraying process. It has been shown that the change in liquid viscosity leads to significant changes in drop size distribution. The correlation for Sauter mean diameter as function of the shear and extensional viscosity was proposed.

The effect of shear and extensional viscosities on atomization of Newtonian and non-Newtonian fluids in ultrasonic inhaler.

The paper contains results of the experimental study on atomization process of aqueous solutions of glycerol and aqueous solutions of glycerol-polyacrylamide (Rokrysol WF1) in an ultrasonic inhaler. In experiments the different concentration aqueous solutions of glycerol and glycerol-polyacrylamide have been tested. The results have been obtained by the use of laser diffraction technique. The differences between characteristics of ultrasonic atomization for test liquids have been observed. The analysis of drop size histograms shows that the different sizes of drops have been formed during atomization process. The present study confirmed the previous reports which suggested that the drops size changes with the increase in viscosity of solution changes in spray characteristics were also observed. It has been shown that the shear and extensional viscosities affect the process of atomization.

Characterization of sprays for thermo-stabilized pneumatic nebulizer

The research presents the nebulizer spray chamber temperature controller responsible for controlling temperature of aerosol produced as a result of nebulizing process. The motivation to make an attempt to improve modern pneumatic devices was the shortage of this kind of apparatuses on the market allowing the production of thermos aerosol. A designed temperature controlling system for pneumatic nebulizers aims at increasing and stabilizing temperature of produced aerosols and increasing aerosol therapy safety. The system is intended for producing aerosol in the process of pneumatic nebulization with the temperature similar to that of the human body. Experiments that were carried out confirmed good performance of the device. It was proved that with the increase of temperature the amount of big droplets fall and the entire spectrum of the droplet diameter moves towards smaller droplet diameter values. Reduction of liquid viscosity related to the increase of temperature leads to the reduction of droplet diameter and, as a result, the reduction of the Sauter mean diameter value.

The modified swirl sedimentation tanks for water purification.

This paper discusses design, evaluation, and application for the use of swirl/vortex technologies as liquid purification system. A study was performed using modified swirl sedimentation tanks. The vortex separators (OW, OWK, OWR and OWKR) have been studied under laboratory conditions at liquid flow rate from 2.8⋅10-5 to 5.1⋅10-4 [m3/s]. The pressure drop and the efficiency of purification of liquid stream were analyzed. The suspended particles of different diameters were successfully removed from liquid with the application of swirl chambers of proposed constructions. It was found that damming of liquid in the tank increases alongside liquid stream at the inlet and depends on the tank construction. The efficiency of the sedimentation tanks increases alongside the diameters of solid particles and decrease in the liquid flow rate. The best construction proved to be the OWR sedimentation tank due to smallest liquid damming, even at high flow rates, and the highest efficiency of the purification liquid stream for solid particles of the smallest diameter. The proposed solution is an alternative to the classical constructions of sedimentation tanks.

The effect of additional aeration of liquid on the atomization process for a pneumatic nebulizer

&NA; At this paper the effect of aeration on the droplet size distribution of the aerosol have been analyzed. The atomization process was carried out using a pneumatic nebulizer which was equipped with a modified nebulizer cup. This modified nebulizer cup was combined with an additional source of gas bubbles. The measurements of the droplet sizes obtained by the use of the digital microphotography method and analyzed by Image‐Pro Plus software. The analysis of the experimental studies proved that an increase in the flow rates of additional gas leads to the increase in the number of small droplets and the decrease of the number of drops of large diameter. Additionally, the mean droplet diameter decreases with the increase of the flow rate of aeration gas. A correlation equation was proposed, which describes the relationship between the mean diameter of droplet and the volumetric flow rate of additional gas. The increase in the bubble volume discharging through a single orifice causes the increase of the flow rate of aeration gas. The modifications of construction of atomizer lead to the better effectiveness of nebulization. Graphical Abstract Figure. No caption available.

Atomizers with the Swirl Motion Phenomenon

The liquid atomization is very important and widespread process in many branches of industry and in agriculture. The technology development, better construction solutions to improve atomization process for the specific application are searched for. Depending on the assignment on which the atomizer is to be used, there are different requirements. Atomization itself doesn’t mean that the process proceeds in a correct and that performance of the spray system is optimum. The application of the effervescent atomizer witch swirl motion phenomenon improves of atomization process compared to pressure-swirl or effervescent atomizers, affects aerosol quality, improves atomization process and ensures its optimization. The spray parameters are influence by many factors: geometric dimensions, liquid properties and operational conditions. The dimensions of atomizer outlet, mixing chamber, aerator have the most important impact on the atomization process. Viscosity and surface tension affect Sauter mean diameter. Viscosity also affects spray angle, while the significant influence of the surface tension on the spray angle has not been shown.

Practical Aspects of Settling Tanks Design

The following work discusses the phenomenon of solid particle settling, presents the characteristics of suspensions and the fundamentals of sedimentation. The velocity of a solid particle free settling has been characterized as well as the sedimentation velocity. Additionally, the paper tackles upon the issue of a liquid stream purification and wastewater purification, where various devices used for the purpose have been characterized, such as horizontal settling tanks, swirl settling tanks and Dorr settling tanks. A special attention was paid to the characteristics of swirl settling tanks, their advantages and potential applications. Also, the outcomes of the research performed to develop the said devices have been described. The aforementioned research considered the influence from the advanced settling tank design components introduced over the purification efficiency of liquid streams from heavy and light fractions, such as inlet or outlet connectors or a partition inside the device. The damming of liquid and the values of local resistance factors have been evaluated as they differ in various technical solutions for settling tanks. The research allowed to determine the construction marked with the highest efficiency in purification of liquid stream, which gives us a possibility to develop the option for analyses with regards to the devices of this type.

Aerosol Therapy Development and Methods of Increasing Nebulization Effectiveness

In this chapter, the atomization process in medical nebulizers are analyzed on the basis of our own and literature results of the studies. It should be underlined that contemporary respiratory tract diseases belong to one of the most frequent and the fastest developing diseases in the world which people of wide age range fight with. Consequently, aerosol therapy belongs to constantly developing areas, which results in the advent of new and more effective pharmaceuticals as well as modern medical devices used in atomization of drugs. It is important to mention that the effectiveness of drug delivery to a patient’s respiratory tract depends on the knowledge and keeping the necessary rules of using inhaling methods under various conditions. The attempts presented in the article and regarding nebulization effectiveness increase showed a visible decrease of drop size of the generated aerosol while drop size histograms became more homogenous. Taking into consideration literature reports regarding inhalation therapy, you can come to the conclusion that nebulization of drugs constitutes an effective method in drug delivery to the respiratory system and can be widely implemented in medicine.

Design and Study of Conical Pressure-Swirl Atomizers

The paper shows the results of experimental studies for two-phase swirl atomizers with two inlet ports different in terms of design. The effect of volumetric liquid and gas flow rate and the height and diameter of mixing chamber on the discharge coefficients, histograms, radial distributions of mean droplet diameters in the drop stream and the mean Sauter diameter were determined. The studies were conducted within the air flow rates not exceeding 5.6·10−4 [m3/s] and water flow rate 1.11·10−5 [m3/s]. It was shown that the discharge coefficient increases with the higher Reynolds number for the liquid and decreases with the higher gas flow rate. The increased liquid flow rate caused greater drop diameters and increased gas flow rate allowed to obtain droplets with smaller sizes. The value of Sauter means that the diameter is dependent on the ratio of height to the diameter of mixing chamber. The rapid increase in the mean droplet diameter occurs above the value of H S /D S ≈ 2.75. It was further noted that higher gas flow rate within the aerosol axis gives rise to the drops with smaller diameters and there is a clear difference in the size of droplets between the central stream area and its edges. In addition, the empirical correlation was proposed for the discharge coefficient as a function of work characteristics and geometric dimensions of the atomizer. The obtained data can be used for designing new atomizers and are essential from the viewpoint of agriculture or combustion processes.

Light and Heavy Pollutant Removal by Modified Swirl Sedimentation Tank – Design and Study

The paper shows the effect of volumetric flow rate of liquid and diameters of solid particles in the sedimentation tank for the water contaminated with sediment and oil substances on the effectiveness of the tank. The effect of liquid flow rate on liquid damming has been studied. It has been shown that the liquid damming in the tank increases with increasing a volumetric flow rate of liquid at the inlet. The determined value of the loss coefficient is 3.06. The effectiveness of sedimentation tank for heavy fraction increases with the diameter of solid particles. It has been shown that an increase in the liquid flow rate reduces the effectiveness of the tank, both for the heavy and the light fractions. The vortex sedimentation tank of the proposed construction allows for the simultaneous removal of the heavy and light fractions from water and their partial separation.