Use Of Compressed Gas Research Articles

Life Cycle Assessment of Biomethane vs. Fossil Methane Production and Supply

Considering the current geopolitical situation that has hindered the gas supply gas from Russia, Europe’s main supplier, it is necessary to find alternative routes to guarantee the Italian gas stocks in winter at a reasonable cost. Such energetic strategies should consider the environmental sustainability of the different available options, fitting the targets of the EU environmental policy. With the aim of supplying a quantitative tool to support the European green transition, this paper reports the entire life cycle assessment (LCA) of three different options for the production and supply of natural gas/methane in Italy: the production of biomethane from biogas (considering a real-scale plant in Italy), the use of liquefied natural gas (LNG) supplied by Qatar by vessel, and the use of compressed gas delivered from Algeria via pipeline. The application of the LCA standardized method allowed for the quantification of the environmental benefit provided by the first option, against all the considered impact categories, thanks to a combination of several advantages: (a) its low-impact anaerobic production, (b) its exploitation of a waste product from the food/agriculture industries, and (c) its production of valuable by-products, which can be considered environmental credits. The results proved the possible environmental gain resulting from an integrated energy supply system that would be able to enhance the economic fabric of specific areas.

Influence of Different Outlet Diameters on Atomization Performance of Liquid Beset Gas Nozzles

The wet FGD system with the characteristics of stable and mature, which had been widely used in the large thermal power plants. In this system, spray nozzle plays a key role, and the atomization performance of the spray nozzle affects the desulfurization reaction rate and efficiency directly. A new type spray nozzle, liquid beset gas nozzle was came up with in this article. It makes use of compressed gas in the internal pipeline to crush the liquid flowed out of the external pipeline into small particles. To optimize the nozzle's structure and develop its atomization performance, then considered outlet diameters of nozzle as one of the main influencing factors, sets three outlet diameters of nozzles: 4mm, 5mm and 6mm. This experiment with water for medium uses a laser particle size analyzer and a high speed camera for analysis to take atomization performance's tests of liquid beset gas nozzles under different outlet diameters and working conditions. The results of experimental studies were concluded. Firstly, when the outlet diameter is 5mm, the total spraying performance was the best. Because this outlet diameter can make the nozzle be in a balance between effective crush, fully mixing and jams preventing. Secondly, the new type nozzle had certain adaptability, when working pressures changed, and can be widely used in the wet FGD system.

Control and Management of Particulate Emissions using Improved Reverse Pulse-Jet Cleaning Systems

Abstract The control of particulate emissions from various applications such as power generation, cement plants, minerals processing etc. is essential to meet government regulatory standards. Filter bags and cartridge elements are typical common mediums used to separate particulates. A common method used to clean filters in the extraction of particulate matter from a fluid stream, is Reverse Pulse-Jet (RPJ) cleaning systems. The operation of the RPJ cleaning system relies on stored energy in the form of compressed gas, which is usually air. In this paper, the design and application of an efficient cleaning system to minimise the use of compressed gas to achieve the required filter cleaning is described. In an RPJ cleaning system, a high-energy pulse of compressed gas is delivered into the filter medium to rapidly increase the internal pressure and, in the case of filter bags, accelerate the filter material to force the break-up of dust cakes that form on the filter surface. One key component of the cleaning system is an extremely fast acting valve that controls the flow of the high pressure gas, the other is the blowtube. The blowtube is a commercial steel pipe with a number of outlet orifices distributed along the longitudinal axis and centrally located above each filter. The cleaning system improvements have been achieved by advances in valve and blowtube design that have enabled increases in the peak pressures developed in the filters whilst minimising the response rate of the system to decrease the air consumption. The store of potential energy must be effectively and efficiently converted into kinetic energy to utilise the available energy to build pressure in the filter. Thus, by improving the RPJ cleaning system the operating costs associated with the compressors are reduced thereby decreasing the environmental impact of operating filter cleaning systems, to more efficiently remove particulate matter from fluid streams.

Design for Occupant Evacuation of Underground Exhibition - Beijing National Convention Center Redevelopment

The 3rd generation fire truck takes use of compressed gas as spraying medium. By way of the especially designed spraying device in the 3rd generation fire truck, the extinguishing agents mixed with compressed gas uniformly, are spraying to fire fields in microdots with high speed and high flux. The extinguishing agents’ microdots with high kinematic energy can penetrate into the flame and affront the flame with more interface areas. The extinguishing efficiency is improved significantly consequently. In a fire fighting by the 3rd generation fire truck, fire can be extinguished more quickly, larger field of fire can be controlled, water damage and environmental pollution is decreased too. The 3rd generation fire truck can also help positive pressure ventilating, cooling fire, blowing and diluting the toxic smoke, and rescuing persons from the fire. Up to the present, different kinds of the 3rd generation fire trucks have been successfully developed such as turbojet fire truck, water mist fire truck, compressed air-foam A/B fire truck, aerosol fire truck, compound spraying fire truck and positive pressure ventilating truck etc. They are playing important roles in fighting fire in urban building, petrochemical enterprises, underground facilities, aircrafts and others.

The 3rd Generation Fire Truck and its Spraying Technique

The 3rd generation fire truck takes use of compressed gas as spraying medium. By way of the especially designed spraying device in the 3rd generation fire truck, the extinguishing agents mixed with compressed gas uniformly, are spraying to fire fields in microdots with high speed and high flux. The extinguishing agents’ microdots with high kinematic energy can penetrate into the flame and affront the flame with more interface areas. The extinguishing efficiency is improved significantly consequently. In a fire fighting by the 3rd generation fire truck, fire can be extinguished more quickly, larger field of fire can be controlled, water damage and environmental pollution is decreased too. The 3rd generation fire truck can also help positive pressure ventilating, cooling fire, blowing and diluting the toxic smoke, and rescuing persons from the fire. Up to the present, different kinds of the 3rd generation fire trucks have been successfully developed such as turbojet fire truck, water mist fire truck, compressed air-foam A/B fire truck, aerosol fire truck, compound spraying fire truck and positive pressure ventilating truck etc. They are playing important roles in fighting fire in urban building, petrochemical enterprises, underground facilities, aircrafts and others.

A simple and portable breathing circuit designed for ventilatory muscle endurance training (VMET)

Ventilatory muscle endurance training (VMET) involves increasing minute ventilation (V (E)) against a low flow resistance at rest to simulate the hyperpnea of exercise. Ideally, VMET must maintain normocapnia over a wide range of V (E). This can be achieved by providing a constant fresh gas flow to a sequential rebreathing circuit. The challenge to make VMET suitable for home use is to provide a source of constant fresh gas flow to the circuit without resorting to compressed gas. Our VMET circuit was based on a commercial sequential gas delivery breathing circuit (Pulmanex Hi-Ox, Viasys Healthcare, Yorba Linda, CA USA). Airflow was provided either by a small battery-driven aquarium air pump or by the entrainment of air down a pressure gradient created by the recoil of a hanging bellows that was charged during each inhalation. In each case, fresh gas flow was adjusted to be just less than resting V (E). Eight subjects then breathed from the circuit for three 10min periods consisting of relaxed breathing, breathing at 20 and then at 40L/min. We monitored V (E), end-tidal PCO2 (PetCO2) and hemoglobin O2 saturation (SpO2). During hyperpnea at 20 and 40L/min, PetCO2 did not differ significantly from resting levels with either method of supplying fresh gas. SpO2 remained greater than 96% during all tests. Isocapnic VMET can be reliably accomplished with a simple self-regulating, sequential rebreathing circuit without the use of compressed gas.

High-voltage compressed-gas power transformers

IN a previous article, <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> the author pointed cut the many advantages of high-voltage power transmission in compressed gas. Compressed CO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> at the moderate pressure of 40 atmospheres (absolute) has a dielectric strength about 20 times as high as that of air at normal atmospheric pressure, and compressed SO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> at 40 atmospheres about 30 times as high, so that the line conductors need be separated by only a few inches instead of the customary many feet and may, therefore, be enclosed in a reasonably small pipe line. This system offers opportunities for many important cumulative economies in the terminal equipment also, and this paper is devoted to their discussion. It is shown that the use of compressed gas, instead of oil, as the insulating and cooling fluid makes possible power transformers that are only about one fourth as large as the present ones for the same duty, are for all intents and purposes nonaging, and are highly resistant to damage from internal are-overs, besides many other advantages.

High-Voltage Compressed-Gas Power Transformers

IN a previous article,1 the author pointed cut the many advantages of high-voltage power transmission in compressed gas. Compressed CO 2 at the moderate pressure of 40 atmospheres (absolute) has a dielectric strength about 20 times as high as that of air at normal atmospheric pressure, and compressed SO 2 at 40 atmospheres about 30 times as high, so that the line conductors need be separated by only a few inches instead of the customary many feet and may, therefore, be enclosed in a reasonably small pipe line. This system offers opportunities for many important cumulative economies in the terminal equipment also, and this paper is devoted to their discussion. It is shown that the use of compressed gas, instead of oil, as the insulating and cooling fluid makes possible power transformers that are only about one fourth as large as the present ones for the same duty, are for all intents and purposes nonaging, and are highly resistant to damage from internal are-overs, besides many other advantages.