venturi injector

Additive manufacturing technologies such as directed energy deposition use powder as their raw material, and it must be deposited in a precise and controlled manner. Venturi injectors could be a solution for the highly precise transport of particulate material. They have been studied from different perspectives, but they are always under high-pressure conditions and mostly fed by gravity. In the present study, an optimization of the different dimensional parameters needed for the manufacturing of a Venturi injector in relation to a particle has been carried out to maximize the amount of powder capable of being sucked and transported for a specific flow in a low-pressure system with high precision in transport...

This study was dedicated to introducing a new method for predicting the Sauter mean diameter (SMD) buildup in the swirl cup airblast fuel injector. There have been considerable difficulties with predicting SMD mainly because of complicated flow characteristics in a spray. Therefore, the backpropagation (BP) neural network-based machine learning was applied for the prediction of SMD as a function of geometry, condition parameters, and axial distance such as primary swirl number, secondary swirl number, venturi angle, mass flow rate of fuel, and relative air pressure...

The current approach to gluconic acid production is acetification at 30°C, a temperature which can be difficult to maintain in tropical countries. This study investigated the production of gluconic acid during acetification by Acetobacter aceti WK at high temperatures. An acid-tolerant and thermotolerant species, A. aceti WK, was used for acetification at three different temperatures, namely, 30°C (normal temperature), 37°C, and 40°C (high temperature). Acetification was performed in a 100 L bioreactor with 0...

Injecting ozone by means of a venturi device causes an increase in the mass transfer coefficient with respect to gas dissolution through a microdiffuser. Moreover, it was observed that significant turbidity levels are not formed (<1 NTU) when using a microdiffuser, probably due to the relatively high stirring which avoids formation of intermolecular hydrogen bonds. On the contrary, employing a venturi injector led to the production of high turbidity levels in water (up to 20 NTU). This indicates that formation of supramolecular structures causing this turbidity requires the presence of certain facilitating species which are formed through ozone decomposition mechanisms...

An integrated system combining in pipe thermal pretreatment with a high-solid anaerobic membrane bioreactor (AnMBR) was developed to promote the anaerobic digestion of waste activated sludge (WAS). Two different pretreatment methods investigated were the venturi nozzle treatment (VNT) and steam injector treatment (SIT), both at a low temperature of 70 °C. The biogas production after pretreatment was 23.5-30.5% higher than that of untreated WAS, and the VS based biogas yield was 0.46-0.47 L/g-VS when HRT was 15 days...

The objective of this study was to evaluate the influence of operational conditions and wastewater properties on the removal of pharmaceuticals, contrast media and antibiotics through ozonation, in order to facilitate the optimization of treatment and its implementation on a full scale. Pilot-scale ozone oxidation trials were performed on treated wastewater, before and after post-precipitation, over a seven-month period, including summer and winter months. Hydraulic retention times as short as 7 min were found to be sufficient for organic micropollutant removal...

Projected increases in ocean p CO2 levels are anticipated to affect calcifying organisms more rapidly and to a greater extent than other marine organisms. The effects of ocean acidification (OA) have been documented in numerous species of corals in laboratory studies, largely tested using flow-through exposure systems. We developed a recirculating ocean acidification exposure system that allows precise p CO2 control using a combination of off-gassing measures including aeration, water retention devices, venturi injectors, and CO2 scrubbing...

BACKGROUND: Safe and effective delivery of inhaled nitric oxide (INO) requires the appropriate interface of ventilator and INO delivery device. METHODS: We compared INO delivery using four configurations with the Transport Sinusoidal Bronchotron® and INOmax DSIR Plus® in a lung model. Ventilator settings and lung model values were held constant. Delivered NO, NO2 , and inspired oxygen (FIO2 ) were measured. The mean difference between set and measured NO was calculated and compared using ANOVA...

AIMS: To evaluate the comparative impact of high initial concentrations of acetic acid (AAi ) and of ethanol (ETi ) on acetification rate (ETA). METHODS AND RESULTS: Acetic acid bacteria (AAB) were cultivated in a 100-l internal Venturi injector bioreactor. To quantify the oxygen availability, the 1.0 l min(-1) air inflow rate for the start-up phase (25 l) while 3·0 l min(-1) for the operational phase (75 l) achieved a high oxygen transfer coefficient (kL a). Changes in cell wall by TEM images and the remained ADH and ALDH activities confirmed the high acid tolerance ability of AAB...

The effect of aerator module configuration, liquid flow rate and diffuser submergence on oxygen transfer efficiency was examined in a surface aeration system with venturi injectors using the clean water test. Six venturi aerator modules were evaluated and the results indicated that better aeration efficiencies could be achieved by simply changing the way the venturi aerators were connected. Among all the configurations examined (modules a-f), two and three aerators connected in parallel (modules d, e and f) were able to bring more oxygen into water than the others...

Six aerator modules constructed using venturi air injectors connected in either series or parallel were evaluated and compared for their oxygen transfer coefficients (OTC), standard oxygen transfer rate (SOTR), and standard oxygenation efficiency (SOE) determined by clean water tests. Modules in series (module a, b, c) included one, two, and three venturi injectors, respectively. The aerator module with two (module d) and three (module e, f) venturi injectors in parallel were used, while module f had less friction and more even flow rate in each line compared with module e...

An air micro-bubble bioreactor (AMBB) using a free self-adapted microbial population, 15 dm3 working volume, was used for aerobic treatment of winery wastewater. This reactor utilizes a Venturi injector in conjunction with mass transfer multiplier nozzles, which allow an efficient oxygen transfer. The reactor can operate in batch or continuous conditions. The dynamics of chemical oxygen demand (COD), biomass and total contents of polyphenolic compounds was followed throughout each trial. The wastewater COD ranged between 4...

PURPOSE: To assess the folding and implantation of the single-piece EasAcryl 1 intraocular lens (IOL) and the maintenance of the tunnel structure and capsular bag stability after implantation. SETTING: S. Orsola Hospital Department of Pathophysiologic Optics, University of Bologna, Bologna, Italy. METHODS: This study comprised 300 cases of EasAcryl 1 IOL implantation. First, a 3.2 mm corneal incision was made according to preoperative astigmatism followed by a 5...

This study evaluates the feasibility and safety of a 6Fr hydrodynamic thrombectomy catheter, the Hydrolyser, in native coronary arteries and aortocoronary bypass grafts. With use of a conventional contrast injector, saline solution is injected into the narrow lumen of the catheter which makes a 180 degrees bend at the tip. The resultant high-velocity jet (150 km/hour) is directed over a sidehole near the tip into a wide exhaust lumen. As a consequence of the Venturi effect, thrombus is sucked into that sidehole, fragmented, and removed through the wide exhaust lumen into a collection bag...

UNLABELLED: The ISO 8600-2-1 draft standard concerns measuring methods for ventilation properties in rigid bronchoscopes. Two lung models were designed in accordance with this draft, one for conventional ventilation, and the other for jet-ventilation (venturi ventilation). Lung model I: An air supply was connected to a 4 liter container. The test object (bronchoscope) was exposed to air flowing out of the container through the bronchoscope, and the pressure in the container was recorded...

Between January 1977 and December 1978, 24 patients with recurrent or chronic spontaneous pneumothorax were treated in the Hong Kong University Cardiothoracic Centre at Grantham Hospital by talc pleurodesis. Talc poudrage had been carried out under local infiltration anesthesia by a technique that utilizes the Venturi principle and the help of an oxygen injector, used normally for ventilating a patient during bronchoscopy with a rigid bronchoscope. By using this method of poudrage, a uniform application of the powder over the whole pleural surface can be achieved and successful pleurodesis can be obtained in all patients under local anesthesia...

A coaxial jet ventilation catheter capable of entraining liquid water by Venturi effect was assembled by inserting an epidural catheter (water injector tube) into a 69-cm-long, 3-mm-i.d., outer jet delivery tube. Gas jet flow in the outer tube produced a negative pressure in the inner injector tube. The entrainment pressure could be varied by increasing or decreasing the distance between the injector and jet portals. The quantity of entrained water could thus be regulated between 8 +/- 1 to 44 +/- 2 mg/L of gas by decreasing this distance from 3...

Venturi jet ventilation with the oxygen injector needle placed within the lumen of the laryngoscope was studied systematically in two dogs undergoing repeated general anesthesia suspension laryngoscopy. Using a total body plethysmograph, the effect of changes of needle angle, position and its effect on tidal volume delivery were measured. The changes of pressure regulator, flow rate and needle size were correlated with the volume delivery. Intratracheal pressure during Venturi ventilation was measured. Correlation of arterial blood gases and minute ventilation with the system was done...

The authors report an original procedure for respiratory assistance during flexible bronchoscopy in infants and toddlers. The injector is directly connected with the operating channel of the bronchoscope. Ventilation parameters are pre-regulated before introducing the fiberscope into the respiratory tree. Insufflation volumes are restricted to 5 ml/kg at the tip of the bronchoscope, on a basis of 40 to 60 cycles per minute, according to children's age. A venturi effect may occur as discrepancy between bronchi and the size of the fiberscope does exist...

In this preliminary study with seven dogs, ventilation with a Sanders bronchoscope attachment coupled to the Norton metal endotracheal tube and use of a jet O2 injector system proved adequate for sustained oxygenation and acid-base balance. This system is shown to be superior to the conventional anesthesia volume ventilator when used with the cuffless metal endotracheal tube. The ventilatory capability can be easily adjusted upward and downward by changing the driving pressures of the reducing valve. Peak intratracheal and transtracheal pressure measurements show the pressures encountered to be similar to those of conventional volume ventilation techniques...