Pressure flow characteristics of the valve in spacer devices.
نویسندگان
چکیده
The valve system in the mouth piece of two spacer devices was analysed. Pressures required to open and close the non-rebreathing valve were very low (less than 0.1 kPa). Inspiratory flow requirements were within physiological limits for infants' normal tidal breathing. Expiratory flow requirements varied significantly, and the flow required to prevent rebreathing from the chamber may exceed the physiological flow limits for normal tidal breathing.
منابع مشابه
Simulation and investigation of the effect of oil flow rate, electric signal of flow control valve and controller on the performance of a wet clutch
The using of wet clutches and hydraulic control devices causes a smoothly torque transfer. In this study, a wet clutch was simulated in Simulink MATLAB software. Firstly the mechanical section of the clutch was modeled and then the hydraulic section was simulated with the addition of electric flow control valve and inlet and outlet of oil flow. Finally, the effects of oil flow rate, electric s...
متن کاملInvestigation of the Flow and Cavitation in a Butterfly Valve
Since knowledge on hydrodynamic torque of a butterfly valve is very important for butterfly valve design, its hydrodynamic torque is investigated in this paper. In reality, the investigation of the loss coefficient and torque from some experiments will take a long time and a lot of money. This paper presents a statistical study of the flow past the butterfly valve in a static analysis using com...
متن کاملThe use of wavelet-artificial neural network and adaptive neuro-fuzzy inference system models to predict monthly precipitation
In water supply systems, One of the most important components as safety unit and the current controller (Switching flow and regulate the amount of flow) used in the arrangement of lines of water. In this study, according to multiple ponds in Tanguiyeh dam water pipeline to industrial and mining company Gol Gohar Sirjan Butterfly valve used in these ponds using Fluent software simulation has bee...
متن کاملPressure flow characteristics of the valve in spacer devices 1307 During expiration the flows
During expiration the flows required to close the Volumatic valve were slightly higher than those required to open the valve, but lie still in a range easily achievable by infants. The flows required to close the Nebuhaler valve were significantly higher than those required to close the Volumatic valve. In the vertical position the expiratory flows averaged 73.9 ml/second (range 69-8-81*5 ml/se...
متن کاملNumerical Simulation of the Effect of Valve Opening and Particle Concentration on the Erosion Damage in Ball Valves of Pressure Reducing Station
Ball valve is one of valves that have many applications in industry especially in gas delivery systems. This kind of valve is categorized in the on- off flow control valve. This study aims to investigate unusual application of ball valve to control fluid flow in the oil and gas industry and its destructive effect including erosion of ball and body of valve. Simulation of industrial ball valve i...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Archives of disease in childhood
دوره 64 9 شماره
صفحات -
تاریخ انتشار 1989