68 results about "Limiting oxygen concentration" patented technology

The Reduced Oxygen Breathing Device (ROBD2) is an apparatus that dilutes the oxygen present in air to concentrations below 21% by mixing the air with nitrogen. The purpose of this dilution is to simulate the reduced oxygen concentration available as one ascends in altitude. The ROBD2 is unique and different from previous devices that reduce the concentration of oxygen in room air via dilution with nitrogen gas in that it uses sophisticated gas regulating devices known as mass flow controllers. The ROBD also employs a gas extraction device as an independent component of the system that can separate nitrogen gas from air for use in the device.

A nitrogen oxide sensor enabled to enhance the measurement concentration of a total of nitrogen oxides by oxidizing or reducing the nitrogen oxides on the surfaces of electrodes in addition to the control of an oxygen concentration by an oxygen pump. An electrode (3a) in a gas chamber (18) constructing an oxygen pumping portion (3) is made of a material (e.g., Pt-3 wt % Rh) having a function to oxidize a nitrogen oxide gas.

This invention sets forth a commercially viable diesel combustion system that meets environmentally acceptable levels of NOx emissions (i.e. 0.2 g/bhp-hr or lower across a full map of engine speeds and loads) without the need for use of NOx aftertreatments, and simultaneously maintains engine-out PM emissions relatively close (e.g. with smoke levels at or below 3 BSN) to environmentally acceptable PM post-aftertreatment levels. The invention achieves these results by operating within a unique combination of parameters. These parameters comprise: (1) charge-air oxygen concentration below 16%, preferably between 10% and 15%, more preferably between 11% and 14%, and most preferably between 12% and 13.5% for virtually all engine operating conditions (but not necessarily at no-load or low load conditions), (2) fuel injection pressures at or exceeding 1800 bar, preferably exceeding 2100 bar, more preferably exceeding 2300 bar, and most preferably exceeding 2500 bar, at most engine speeds and loads, and (3) charge-air mass/fuel mass ratio between 25:1 and 45:1 for medium and high loads. Furthermore, the system is preferably run continuously slightly lean of stoichiometry, providing just enough excess oxygen to facilitate completeness of combustion and to maintain an exhaust oxygen level sufficient for continuous trap regeneration at a balance point in operation.

Disclosed is a gas sensor comprising a first internal space for making communication with the external space via a first diffusion rate-determining section, a first electrochemical pumping cell for controlling the oxygen concentration in the atmosphere in the first internal space to have a predetermined value, a second internal space for making communication with the first internal space via a second diffusion rate-determining section, a second electrochemical pumping cell for finely adjusting the oxygen concentration in the atmosphere in the second internal space to have a predetermined value, a third internal space for making communication with the second internal space via a third diffusion rate-determining section, a third electrochemical pumping cell for pumping out oxygen produced by reduction or decomposition of a component having bound oxygen in the measurement gas in the third internal space, and an ammeter Ip for detecting a pumping current which is allowed to flow in accordance with the pumping operation effected by the third electrochemical pumping cell. Accordingly, it is possible to avoid interference exerted on the sensitivity for NO by the change in oxygen concentration in exhaust gas, and improve the measurement accuracy for the measurement gas component.

The invention relates to a metal crown lid internal gasket sealing material with an oxygen absorbing function. The metal crown lid internal gasket sealing material is prepared by respectively adding 2-30 parts by weight of single-components of different types or an oxygen absorbent of a compound component by taking a thermoplastic elastomer as a base material. The metal crown lid internal gasket sealing material can be processed into a metal crown lid gasket by adopting an existing non-oxygen absorbing gasket machining process, can absorb residual oxygen of a headspace in an absorbing bottle while keeping the original machining and sealing property of the gasket, and ensures that the oxygen concentration is reduced to a limit oxygen concentration of 0.5ml/l from 210ml/l, thereby prolonging the quality guarantee period.

A process for incinerating combustible materials including the steps of: delivering combustible material and inlet gases to a primary combustion chamber, the inlet gases having an oxygen content of at least 50 vol %; burning the combustible material with the oxygen of the inlet gases in the primary combustion chamber producing flue gases and solid particulates as thermal decomposition products of the burnt combustible material; passing the flue gases and particulates to a secondary combustion chamber where further combustion occurs; cooling the flue gases exiting the secondary combustion chamber; returning a portion of the cooled flue gases to at least one of the combustion chambers where the cooled gases moderate the temperature in the at least one chamber; and passing the remaining portion of cooled flue gases on to a flue gas purification system where pollutants in the flue gases and particulates are substantially converted to benign compounds or removed entirely before the flue gases are emitted into the atmosphere.

An exhaust gas purifying system includes: a NOx trapping agent (2) which adsorbs nitrogen oxide when an excess air ratio of exhaust gas is more than 1, and releases nitrogen oxide when the excess air ratio is 1 or less; a NOx purifying catalyst (13) which reduces nitrogen oxide to nitrogen; and an oxygen concentration controller which controls oxygen concentration in the exhaust gas. When the excess air ratio of the exhaust gas is more than 1, nitrogen oxide is adsorbed to the NOx trapping agent (2). When the excess air ratio of the exhaust gas is 1 or less, the oxygen concentration controller controls the oxygen concentration of the exhaust gas at an inlet of the NOx purifying catalyst between 0.8 and 1.5% by volume, so that the NOx purifying catalyst reduces nitrogen oxide released from the NOx trapping agent.

The invention discloses an oxygen uptake instrument which comprises a sealing mask assembly, an air pipeline, an oxygen branch pipeline, an air flowmeter and a control device, wherein the sealing mask assembly is provided with an expiration hole and an admission hole; an expiration one-way valve which is communicated with the atmosphere is arranged at the expiration hole of the sealing mask assembly; an admission one-way valve is arranged at the admission hole; the air pipeline is provided with a first end and a second end; the first end of the air pipeline is communicated with the expiration hole of the sealing mask assembly in an airtight manner; an air inlet one-way valve which is communicated with the atmosphere is arranged at the second end of the air pipeline; the oxygen branch pipeline is communicated with the air pipeline in an airtight manner; the oxygen branch pipeline can be connected with an oxygen supply source through a solenoid valve; the air flowmeter is arranged in the air pipeline; the control device is connected with the air flowmeter and the solenoid valve and is used for controlling the oxygen flow inside the oxygen branch pipeline according to individual air expiration amount detected by the air flowmeter, of an oxygen taker. By adopting the oxygen uptake instrument disclosed by the invention, not only is the taken oxygen concentration automatically and accurately controlled and monitored, but also a great deal of oxygen is saved, and the comfort in oxygen taking is improved.

A limiting current type oxygen sensor comprises an ion conductor, a pair of electrodes, a gas diffusion mechanism for supplying a diffusion-rate-determined gas, and a heater for heating the ion conductor. The gas diffusion mechanism includes a gas diffusion bore and an internal space communicating with the gas diffusion bore. In a first embodiment, the gas diffusion mechanism is configured such that the thickness (lin) of the internal space is formed equal to or larger than the bore diameter (S1) of the gas diffusion bore. This makes it possible to dominate diffusion-rate-determinateness in the gas diffusion bore and minimize the influence of diffusion-rate-determinateness in the internal space, thereby sensing the limiting current value accurately. In a second embodiment, the gas diffusion mechanism is configured such that an oxygen concentration gradient within the internal space satisfies the following expression: 1/I lim = (1/4FDC o2 ){(l/S) + (l in /S in which is based on a relationship between the Faraday constant (F); a diffusion coefficient (D); an oxygen concentration (C o2 ); a bore area (S) of the gas diffusion bore; a bore length (1) in the axial direction of the gas diffusion bore; a distance (l in ) in the internal space between the first elextrode and the inner surface opposed thereto; an effective cross section (S in ) of the internal space; and an output current value (I lim ).

A ventilator (1) comprises a gas pipe system for supplying respiratory gas to a patient; at least one monitoring device is provided for monitoring the oxygen concentration in the respiratory gas; saidmonitoring device includes at least one receptacle (5) for an oxygen sensor (12, 15); a galvanic oxygen sensor (12) or a paramagnetic oxygen sensor (15) can be selectively inserted into the receptacle (5).

The invention relates to an efficiency calculation method for a novel SCR (Selective Catalytic Reduction) denitration device. The efficiency calculation method comprises the following steps: (1) selecting and sampling a sampling measuring point in the manner as specified in GB/T16157-1996 Method for Determining Particulate Matters in Stationary Pollution Source Exhaust Gas and Sampling Gaseous Pollutants 4.2; and (2) performing sampling measurement for flue gas flow speed, oxygen concentration and nitric oxide concentration at each sampling point at the inlet and outlet of the SCR denitration device, adding the flue gas flow speed and calculating nitric oxide concentration and efficiency in the flue gas. According to the efficiency calculation method, the flue gas flow speed is added as the factor participating into the calculation in a detection process, the calculated nitric oxide concentration is more accurate and scientific, and the calculated denitration efficiency more conforms to the practical operation condition of the equipment.

In the reaction of catalytic gas phase oxidation induced by the supply of at least a raw material to be oxidized and a molecular oxygen-containing gas to a reactor for catalytic gas phase oxidation, a method for starting up the reactor for catalytic gas phase oxidation is disclosed which is characterized by causing the raw material and the molecular oxygen-containing gas to pass a range in which the concentration of the raw material is less than the lower explosion limit of the raw material and the concentration of oxygen is not less than the limiting oxygen concentration, but excluding the concentration of the raw material of 0 vol. %. The method enables the reactor to be started up economically and safely by avoiding the explosion range induced by the composition of a raw material and a molecular oxygen-containing gas supplied to the reactor and decreasing the amount of a diluting gas to be supplied.

On-site generation of a fracturing fluid stream system includes a fracturing fluid generation assembly and a fracturing fluid supply assembly. The fracturing fluid generation assembly is configured to receive a hydrocarbon stream and to generate a fracturing fluid stream from the hydrocarbon stream. The fracturing fluid stream has an oxygen concentration, which is less than a limiting oxygen concentration for supporting combustion of a combustible fluid that is present within a subterranean formation. The fracturing fluid stream also has a combustible portion, which defines a concentration that is below a lower flammability limit of the combustible portion in the fracturing fluid stream. The fracturing fluid supply assembly is configured to receive the fracturing fluid stream and to convey the fracturing fluid stream to the subterranean formation to fracture the subterranean formation.

A method for analyzing the oxygen concentration of a gas with an oxygen concentration analyzer of such a type that a probe sensor, when supplied with a gas to be analyzed, produces an electrical output which is proportional to the concentration of oxygen in the gas, comprising the steps of preparing a first gas mixture in which an oxygen-free gas and a sample gas are mixed at a certain flow ratio and a second gas mixture in which the oxygen-free gas and the sample gas are mixed at a different flow ratio than in the first gas mixture, passing the first gas mixture and the second gas mixture asynchronously into the probe sensor, and comparing the electrical outputs from the sensor for the first gas mixture and the second gas mixture, as well as the proportions of the flow of the sample gas in the first gas mixture and the second gas mixture to thereby calculate the oxygen concentration in the sample gas. The method eliminates the need to perform frequent zero adjustment and enables the oxygen concentration in the sample gas to be measured with consistent results.

An exhaust gas sensor (100; 200) is configured so as to detect an oxygen concentration or air-fuel ratio in exhaust gas. The exhaust gas sensor includes a sensor element (10) and a manganese reaction layer (20). The sensor element detects an oxygen concentration or air-fuel ratio. The manganese reaction layer is formed on at least part of a surface of the sensor element and is formed of a substance containing an element capable of generating a complex oxide having manganese through reaction with a manganese oxide in the exhaust gas. The exhaust gas sensor is configured to detect an oxygen concentration or air-fuel ratio in exhaust gas of an internal combustion engine that utilizes a fuel having a Mn concentration in excess of 20 ppm.

The invention provides a combustion criterion analyzing method of a dry chamber near an oil tank under impact of metal chips. A relation diagram of changes of an airplane combustion envelope along with an airplane flight profile is calculated through a formula according to an airplane flight profile diagram and a formula of the fuel oil flash point temperature. A combustion triangular diagram is drawn by analyzing the influence relation between the temperature and a fuel oil combustion limit, the pressure and the fuel oil combustion limit, the height and the fuel oil combustion limit and the fuel oil components and the fuel oil combustion limit respectively and calculating the limit oxygen concentration of the fuel oil. Combustion criteria can judge conditions of combustion of the dry chamber near the oil tank under different flight heights accurately, expression forms of a fuel combustion envelope and a combustion triangular form are simple and intuitionistic so that the method is beneficial for reduction of probability of occurrence of airplane combustion explosion, viability of an airplane is improved, and meanwhile the method can be applied to judgment of combustion when oil tanks of communication media such as motorbikes, automobiles and steamships are impacted by high-speed metal chips.