Amount Of Compressed Air Research Articles

Infrared signal of the lobed mixer with external air mixing

AbstractIn order to know the characteristics of reducing the exhaust gas infrared signal of the lobed mixer according to the external air mixing ratio, an infrared signal and temperature distribution measurement using a micro-turbojet engine is performed. A certain amount of compressed air is supplied through an external duct mounted on the micro-turbojet engine exhaust to simulate bypass flow, which is mixed with high-temperature core air and ejected to the atmosphere. The exhaust nozzle used in the experiment is a lobed mixer with a lobe of sinusoidal shape and is designed to have a penetration of 0.2. Exhaust gas temperature and infrared signal are measured according to distance from nozzle outlet under conditions of bypass ratio of 0.5, 1.0 and 1.4. Infrared reduction rates are compared to data without compressed air supply. As a result of the experiment, as the bypass ratio increased, the infrared signal of the exhaust gas and the temperature decrease with bypass ratio increase, and in the case of a bypass ratio of 1.4, the effect of reducing the temperature is observed even at a long distance. In addition, we compared the results of previous studies of a simple cone shape without mixer with infrared reduction effect. The results show that the lobed mixer has a greater effect on reducing the temperature of the exhaust gas and reducing the infrared signal than the cone nozzle. The structure of the mixed jet flow is also studied through Schlieren visualisation and 3D temperature distribution.

Investigation of the pneumatic system of recuperative hydraulic drive of a timber truck

The direction of scientific research connected with increasing the efficiency of timber road transport by reducing energy losses in the hydraulic drive of the manipulator in the process of loading and unloading timber has been substantiated. The analysis of scientific works in the field of methods of recuperation of various types of energy in wheeled vehicles, recuperative devices and hydraulic drives, allowing to accumulate and usefully use the energy of compressed air. A perspective diagram of a recuperative hydraulic drive of a timber truck manipulator with a pneumatic system is proposed. The goal of the work is formulated, which is to develop mathematical and simulation models for the functioning of the proposed pneumatic system of a recuperative hydraulic drive for assessing the necessary indicators of its efficiency based on the revealed dependencies. Developed and investigated mathematical and on its basis simulation models of pneumatic system functioning. The dependences of the influence of time on the amount of compressed air, pressure and temperature in the pneumatic accumulator and pneumatic cavities of pneumatic cylinders are obtained.

PENGARUH VARIASI JUMLAH POMPA TERHADAP PERFORMA MESIN SPRAYER DORONG

Knapsack sprayer is the most widely used type of sprayer by farmers, but it is quite tiring when used, because it has to carry a sprayer weighing up to 15 kg and manually pumping to get the pressure requirement in the tank (pressure required of 2 - 7 kg / cm2). Based on these problems, researchers innovate with a new type of sprayer (utilizing wheel rotation that is converted into translational motion to press the pump). The purpose of this study is analyze the influence of the number of pumps to resulting pressure. The study was conducted with 5 repetitions and the distance of experiment was 25 meter. The results show that the number of pumps has little effect, since the number of pumps has no direct effect on the amount of compressed air (this is affected by the same total pumping distance between the use of 1 pump and 2 pumps). Testing using 1 pump and 2 pumps produced a pressure between 1.9 - 2.2 kg / cm2.

A cost-effective compressed air generation for manufacturing using modified microturbines

Compressed air is an irreplaceable energy source for some manufacturing processes, and is also common in applications even when there are alternatives. As a result, compressed air is a key utility in manufacturing industry, but unfortunately the cost of compressed air production is one of the most expensive processes in a manufacturing facility. In order to reduce the compressed air generation cost an unconventional way using a microturbine configuration is proposed. The concept is based on an extraction of a certain amount of compressed air from/after the compressor with the residual air flowing to the turbine to produce sufficient back power to drive the compressor. A thermodynamic and life cycle analysis are presented for several system variations, including a simple cycle without a recuperator and a complex configuration with an intercooler, recuperator and reheating. The study is based on the typical requirements (i.e. quantity, pressure) for a small to medium sized industrial compressed air system. The analysis is focused on the North American market due to the low price of natural gas. The lowest life cycle cost alternative is represented by a microturbine concept with a recuperator, air extraction after partial compression, intercooler and aftercooler. A comparison of an electric motor and conventional microturbine prime movers demonstrates the economic benefit of the proposed compressed air generation method, for the design parameters and utility prices considered.

Theoretical Research on Performance of the Corn Length Grading System

In order to solve the fresh corn grading problem in the corn deep processing enterprise, in this study, the grading system that the corn length was grading index has been proposed. Instead of the method of artificial classification, through the grading system the people have been liberated from heavy manual labor. And, through the theoretical research on the performance of the corn length grading system, the theoretical grading rate has been determined and can reach 11900/h; through analyzing the nozzle purging corn, the best purging position has been determined and was centroid of the corn. When the corn roots was in the former, the nozzle purging effect was best; The impact factors of measuring accuracy in grading system have been analyzed; the amount of compressed air purging corn has been determined and need 5.15 m 3 /h.

Preparation of Samples of Liquid Metal for Analysis

A new unit has been designed to cool metal samples to the required temperature. Compressed gas is used as the cooling medium in the unit and is induced to vibrate by an acoustic radiator. Use of the unit in the electric steelmaking shop at the Severskii Pipe Plant has made it possible to obtain metal samples which are evenly cooled over their entire surface. The amount of compressed air used in the cooling operation is reduced appreciably.

Main Technologies of Life Support System of Evacuated Tube Transportation Vehicle Passenger Cabin

The passenger cabin of evacuated tube transportation vehicle is the airproof shell. In order to ensure the safety of passengers, riding comfort and good health, the cabin should be offered with the right pressure, oxygen and temperature-humidity environment, while eliminating carbon dioxide and impurities, providing clean air, retaining a reasonable proportion of inert gas by the life support systems. Passenger cabin pressure system is specified to a mix of oxygen-nitrogen atmospheres, close to 1 atm, the oxygen partial pressure is slightly higher than the value outside the tube, and carrying amount of compressed air decided by the oxygen demand standard 0.038kg/ (person • h); drying phenomenon does not occur in the cabin, but dehumidifying to control the humidity is needed; Sorbent dosage and purification device design is based on carbon dioxide emissions 24L/ (person • h). These functions are attained respectively by some technologies such as cabin pressure controlling, gas supplying, temperature and humidity controlling, air purification and security technology.

Optimising operation of a biological wastewater treatment application

The objective of this work was to optimize (minimize) the compressed air required to control the rate of ammonia removal in a commercially operated wastewater bioreactor, while still maintaining operation within environmental consent limits. In order to do this, a nonlinear dynamic model based on the International Association on Water Quality (IAWQ) activated sludge model No. 3 was developed, expressing the nitrification kinetics and hydraulic dynamics of the system. From this model a steady state representation of the plant was derived, and simulated for various load characteristics experienced at the facility, and as a result an optimal load profile was developed for the compressed air distribution to the four aerobic zones. The optimal load profile will ensure that the amount of compressed air required to control the rate of ammonia removal is optimized.

Improvement of energy efficiency of servo pneumatic cylinders by optimising velocity profiles

The authors' previous simulation study indicated that different quantities of compressed air will be consumed by a servo-controlled pneumatic cylinder with different velocity profiles under the same control strategy. This motivated the authors to investigate if there is the most energy-efficient profile, which leads the system to use the least amount of compressed air. To avoid solving a set of complicated non-linear differential equations, the non-linear system is linearised through input/output state feedback, then energy efficient optimal control theory is applied to the linearised system. An optimal control strategy is derived with respect to the transformed states of the linear system model. The solution of the state trajectory results in an energy efficient profile. Simulation study has been conducted using both the linearised and original non-linear system models and the simulation results indicated that the profiles obtained in this paper are more energy efficient.