196 results about "Flammability limit" patented technology

The invention discloses a dual-functional catalyst composition and an integrated process for production of olefin epoxides including propylene oxide by catalytic reaction of hydrogen peroxide from hydrogen and oxygen with olefin feeds such as propylene. The epoxides and hydrogen peroxide are preferably produced simultaneously in situ. The dual-functional catalyst comprises noble metal crystallites with dimensions on the nanometer scale (on the order of <1 nm to 10 nm), specially dispersed on titanium silicalite substrate particles. The dual functional catalyst catalyzes both the direct reaction of hydrogen and oxygen to generate hydrogen peroxide intermediate on the noble metal catalyst surface and the reaction of the hydrogen peroxide intermediate with the propylene feed to generate propylene oxide product. Combining both these functions in a single catalyst provides a very efficient integrated process operable below the flammability limits of hydrogen and highly selective for the production of hydrogen peroxide to produce olefin oxides such as propylene oxide without formation of undesired co-products.

An afterburner apparatus that utilizes a novel swirl generator for rapidly and efficiently atomizing, vaporizing, as necessary, and mixing a fuel into an oxidant. The swirl generator converts an oxidant flow into a turbulent, three-dimensional flowfield into which the fuel is introduced. The swirl generator effects a toroidal outer recirculation zone and a central recirculation zone, which is positioned within the outer recirculation zone. These recirculation zones are configured in a backward-flowing manner that carries heat and combustion byproducts upstream where they are employed to continuously ignite a combustible fuel/oxidizer mixture in adjacent shear layers. The recirculation zones accelerate flame propagation to allow afterburning to be completed in a relatively short length. Inherent with this swirl afterburner concept are design compactness, light weight, lower cost, smooth and efficient combustion, high thrust output, wide flammability limits, continuous operation at stoichiometric fuel/oxidizer mixture ratios, no combustion instabilities, and relatively low pressure losses.

The invention provides a novel high-temperature high-pressure explosion limit tester comprising a raw material gas supply apparatus, an explosion determination device, a vacuum generating device, and a controlling device. The explosion determination device is mainly composed of a pressure sensor, a temperature sensor, and an igniter. The explosion determination device is used for determining explosion limit, explosion pressure and explosion temperature of the gas or vapor. The vacuum generating device is used in vacuum pumping upon the explosion determination device. The controlling device is used for determining, controlling and collecting experimental data generated during the experiment. Compared with prior arts, the high-temperature high-pressure explosion limit tester provided by the invention has a temperature testing range of room temperature to 400 DEG C, which is higher than 200 DEG C which is a maximal temperature of instruments in existing standards; the tester provided by the invention has a pressure range of normal pressure to 2.2MPa, which is higher than 1.38MPa which is a maximal pressure of instruments in existing standards; and the tester provided by the invention has a test volume of 10L, which is larger than that of an existing tube-type explosion limit tester, such that a wall effect can be better reduced.

A method using exhaust gas recirculation (EGR) in an internal combustion engine. The engine has at least one “dedicated EGR cylinder”, whose entire exhaust is recirculated back to all the engine cylinders. The dedicated EGR cylinder is operated at a rich air-fuel ratio, and the other cylinders are operated stoichiometrically so that a conventional three way catalyst may be used to treat the exhaust. A fuel injector is used to inject fuel into the combustion chamber of the dedicated EGR cylinder after initiation of the main combustion event. This post injection method overcomes flammability limits of a dedicated EGR cylinder, and increases the hydrogen (H2) and carbon monoxide (CO) in its exhaust.

The invention discloses a tail gas buffer dilution treatment method for safe emission of hydrogen from a fuel cell vehicle and a device thereof. The device comprises a hydrogen buffer, a flow control valve, a draining valve, a flame arrester, an earth terminal, an emergency hydrogen exhaust valve, a hydrogen sensor and a control module. The pulse hydrogen emitted from an anode side of the fuel cell is firstly buffered by the buffer, and a small stream of air introduced from an air path emitted from the cathode side dilutes and sweeps the hydrogen in the buffer; then the diluted hydrogen emitted from the buffer and the gas from a main air pipeline are mixed, thus the volume concentration of the tail hydrogen emitted from the fuel cell vehicle is controlled below the explosion limit concentration 4%, and the purified water discharged from a condenser can be recycled. The tail gas buffer dilution treatment device utilizes the techniques of self-diffusion, multi-tube pass buffer, air mixing and exchange, expansion, condensation and the like to buffer and dilute the hydrogen-containing tail gas emitted from the fuel cell vehicle and separate the water and gas in the hydrogen-containing tail gas, thus eliminating the possible fire hazard and ensuring the safe running of the fuel cell vehicle.

The invention relates to a dry converter coal gas dust-removal system and an explosion protection device thereof. The system comprises a cooling device, a dust remover, an explosion protection device, a draught fan and a switching station; an explosion protection device is connected with flue gas pipelines which are arranged between the cooling device and the dust remover, a draught fan connected with the dust remover and a switching station, wherein the explosion protection device comprises a gas composition analyzer, a gas injecting device and a control device, wherein the gas composition analyzer used for detecting CO and O2 content in the flue gas is arranged on the inlet flue gas pipeline of the dust remover; the gas injecting device is arranged on the flue gas pipelines which are arranged between the gas composition analyzer and the dust remover; the control device compares the CO and O2 content detected by the gas composition analyzer with explosion limit concentration to control the open or close of the gas injecting device; the draught fan is connected with the dust remover, the inlet of the switching station is connected with the draught fan, the outlet is respectively connected with a spread chimney and a coal gas cabinet and is in charge of switching set of flue gas pipelines between the spread chimney and the coal gas cabinet. The invention can reduce explosion rate of the dust remover.

A flammable vapor detector is used to detect flammable vapors in the event of a volatile organic liquid spill near a gas fired appliance, such as a hot water heater. The appliance is mounted at an elevation above the floor while the detector is mounted at or near the floor where the spill may occur. The detector is connected electrically to a safety gas cut-off solenoid valve in the appliance to urge the valve to cut-off the flow of gas to the appliance in the event that the detector detects flammable vapor. Because the detector is below elevation of the appliance, the detector reacts to higher concentrations of flammable vapors than the concentrations of flammable vapors at the higher elevation of the appliance to turn off the gas to the appliance before the combustion air to the appliance reaches a lower flammability limit. The appliance used to describe the invention is a gas fired hot water heater.

A combined-cycle engine having at least one core engine and at least one ramjet engine. The ramjet utilizes a novel swirl generator for rapidly and efficiently atomizing, vaporizing, as necessary, and mixing a fuel into an oxidant. The swirl generator converts an oxidant flow into a turbulent, three-dimensional flowfield into which the fuel is introduced. The swirl generator effects a toroidal outer recirculation zone and an inner central recirculation zone, both of which are configured in a backward-flowing manner that carries heat and combustion byproducts upstream where they are employed to continuously ignite a combustible fuel/oxidizer mixture in adjacent shear layers, which accelerate flame propagation throughout the core flowfield. The swirl generator provides smooth combustion with no instabilities and minimum total pressure losses and enables significant reductions in the L/D ratio of the combustor. Other benefits include simplicity, reliability, wide flammability limits, high combustion efficiency and high specific thrust performance.

A method and apparatus for generating a non-flammable gaseous mixture from a first flammable gas and a second gas in which said first gas is flammable. Air may be extracted from the atmosphere or storage container to be treated. The air is circulated in a conduit (22) via blower (14). A flammable gas is injected (12) into the conduit where it is rapidly diluted to a level below its flammability limit. The method is suitable for unattended automatic treatment over an extended period of time, or a so-called “one shot/quick dump” fumigation where concentrations and flow rates are much higher and the process is under manual supervision.

The invention relates to a method for determining explosion limit of multicomponent mixed gas. The conventional physical and chemical parameters and the mixture ratio of pure gas are adopted to build corresponding explosion limit prediction models aiming at different classes of multicomponent mixed gas, and the built models are utilized to predict the explosion limit of unknown mixed gas. The method comprises the following steps of: 1, collection of modeling samples of the multicomponent mixed gas and the explosion limit data of the multicomponent mixed gas; 2, classified processing of the modeling samples of the multicomponent mixed gas; 3, determination of the physical and chemical parameters and collection of the data; 4, building of the prediction models; 5, confirmation and correction of the models; 6, and application of the prediction models. The explosion limit is an important indicator for measuring the explosion risk of the mixed gas, and a predicting method for researching the explosion limit of the multicomponent mixed gas has importance for the prediction and monitor of the gas explosion. The method is sample and has high prediction accuracy, and the invention provides a simple, fast, accurate and reliable predicting method for predicting the explosion limit of the multicomponent mixed gas.

The invention discloses an intermittently discharged organic waste gas gathering and processing method. After the intermittently discharged organic waste gas passes through a flame arrester, a booster pump and a waste gas gathering cabinet, if the organic waste gas is very high in concentration, the organic waste gas can be burnt directly or directly burnt in a combustion device/a boiler after passing through a purification/decontamination device B, and the heat generated by burning directly generates steam. If the organic waste gas is low in purity, the organic waste gas is thinned to the concentration lower than an explosion limit through a thinning device, the thinned organic waste gas is conveyed to heat storage oxidization/heat storage catalysis/catalytic oxidation devices to oxidize and decontaminate, one part of the gas is switched between the heat storage oxidization/heat storage catalysis/catalytic oxidation devices, one part of the heat generated by oxidization heats the waste gas to arrive at a combustible temperature, and most of the heat generates steam through a waste heat boiler. The intermittently discharged organic waste gas gathering and processing method is capable of realizing energy conservation and environment protection, a pollutant discharge enterprise even can gain profit when treating pollutant, and accordingly the pollutant treatment enthusiasm of the enterprise is greatly increased.

The invention relates to an explosion limit testing device of combustible gas under a high-temperature condition. The device comprises a temperature data collection system, a heating temperature control system, and a supplied gas feeding/gas pumping and purging system. The supplied gas feeding/gas pumping and purging system comprises the following components connected in parallel: a delivering pipe of gas to be detected, an oxygen delivering pipe, an air delivering pipe, and a vacuum pump. The heating temperature control system comprises a round-bottomed flask testing chamber, a heating jacket, a temperature control thermocouple, and a heating furnace. The round-bottomed flask testing chamber is suspended in the heating furnace through an insulation supporting device. The testing device provided by the invention is a semi-closed testing device. A safety valve is provided above the flask, such that pressure can be released in time after explosion occurs, and the flask is prevented from being damaged by detonation pressure. Therefore, the explosion limit of combustible gas under high-temperature condition can be effectively measured, and temperature can be accurately controlled. An upper temperature limit can reach 800 DEG C. Also, the device is convenient to observe, such that testing accuracy is greatly improved.

The invention relates to an underground coal mine gas explosion reaction test device which comprises a controller, an explosion reaction tank, an explosion gas source connected with the explosion reaction tank, and a compressed air source, wherein the explosion reaction tank is internally provided with an ignition electrode and a pressure sensor; the ignition electrode and the pressure sensor are connected with the controller; the device also comprises a vacuum pump and an air compressor which are connected with the explosion reaction tank. After the underground coal mine gas explosion reaction test device is used, the basic parameters such as explosion limit, explosion pressure, explosion pressure rise speed, explosion pressure peak time and the like of underground explosive gas in a macroscopic static state and a turbulence state are simulated, and the influence of turbulence to gas explosion characteristics is analyzed; therefore, a certain guidance is provided for effectively controlling mine gas explosion hazard.

Ethane may be catalytically oxidatively dehydrogenated to ethylene at high conversions and high selectivity in a circulating fluidized bed (CFB) reactor in the presence of oxygen in the feed in an amount above the flammability limit. The reactor has an attached regeneration reactor to regenerate the catalyst and cycle back to the CFB.

A ramjet powered device that utilizes a novel swirl generator for rapidly and efficiently atomizing, vaporizing, as necessary, and mixing a fuel into an oxidant. The swirl generator converts an oxidant flow into a turbulent, three-dimensional flowfield into which the fuel is introduced. The swirl generator effects a toroidal outer recirculation zone and an inner central recirculation zone, both of which are configured in a backward-flowing manner that carries heat and combustion byproducts upstream where they are employed to continuously ignite a combustible fuel/oxidizer mixture in adjacent shear layers and stabilizes flame propagation and accelerates combustion throughout the entire combustor. The swirl generator provides smooth combustion with no instabilities and minimum total pressure losses and enables significant reductions in the L/D ratio of the combustor. Other benefits include simplicity, reliability, wide flammability limits and high combustion efficiency and thrust performance.

The invention provides a nitrogen dilution anti-explosion system in a dry-method cooling and purifying recovery system for a converter gas. The nitrogen dilution anti-explosion system mainly comprises a nitrogen tank, a rapid pneumatic valve arranged on a nitrogen pipe, a gas analyzer mounted on a smoke inlet pipeline of an electrostatic precipitator, as well as a controller, wherein the controller is used for controlling the rapid pneumatic valve to open or close according to a signal collected by the gas analyzer. The nitrogen dilution anti-explosion system can be mounted on the pipeline before smoke entering the electrostatic precipitator, smoke components can be detected timely, when smoke is in an explosion limit range, nitrogen is instantly sprayed into a flue for dilution, and accordingly, the explosion in the electrostatic precipitator is reduced or prevented.

The invention relates to a gradually-expanding premixing porous medium combustor for combusting biomass gasification gas. The combustor is provided with gradually-expanding pipes, wherein a porous medium with catalytic action is filled in each gradually-expanding pipe; a heater is coated outside each gradually-expanding pipe; each gradually-expanding pipe is wholly embedded into a thermal insulating layer; a capacity expansion chamber is formed at an inlet of each gradually-expanding pipe; a tempering prevention piece and a flow equalization plate are arranged in each capacity expansion chamber; and an inlet of each capacity expansion chamber is connected with a premixing tube. Flame deflection and other unstable combustion phenomena can be avoided, flames can be effectively prevented from being blown out of the combustor, the power of the combustor is improved, the working range of the combustor is expanded, and the load and working condition changes of the combustor are met. Moreover, the combustor has a function of adjusting gas flow, and parallel gradually-expanding pipes are prevented from being shut down due to over-low load or prevented from being subjected to over-high load; and the biomass gasification gas can be subjected to super adiabatic combustion in the combustor, the lean flammability limit of fuel is greatly expanded, and the fuel with ultralow heat value can be stably combusted. Meanwhile, the flame area is widened, the combustor contributes to accelerating cracking combustion of tar, and the combustion efficiency is improved.

The invention discloses a flame-suppression and explosion-suppression cryogenic liquefaction device for low-concentration coal bed gas, which comprises a coal bed gas storage system, a coal bed gas compression system, a coal bed gas purification system, a coal bed gas liquefaction and separation system, an LNG (Liquefied Natural Gas) storage system and a refrigerating circulatory system, wherein driving explosion-suppression devices are arranged on the front side and the rear side of the coal bed gas storage system; a filler used for fractionating methane in the coal bed gas and having the explosion-suppression performance is filled in a rectifying tower; the rectifying tower is internally provided with a fire-retardance and explosion-suppression material; the fire-retardance and explosion-suppression material is a fire-retardance silk screen which is laid in the filler at intervals; and the driving explosion-suppression devices can effectively prevent flame from spreading to a gas holder, and can guarantee the safety of the gas holder and an underground coal mine drainage system. The fire-retardance and explosion-suppression material is arranged in the rectifying tower, so that explosion can be prevented even if the methane enters an explosion limit range in a liquefaction extraction process of the methane, and the high-recovery and high-purity methane can be obtained from the low-concentration oxygenic coal bed gas under the condition that deoxygenation is not performed in advance.

The embodiment provides a dust explosion limit test device and a test method thereof. The test device comprises a spherical explosion tank, a heating device, a cooling device and a temperature control device, wherein the outer wall of the explosion tank adopts a double-layer structure with a cavity; the cavity is filled with heat transfer oil; the outer wall of the explosion tank is covered with a thermal insulation layer; a temperature sensor is arranged inside the cavity and used for measuring the temperature of the heat transfer oil; the temperature control device controls the heating device or the cooling device to heat or cool the heat transfer oil according to the temperature measured by the temperature sensor. The test device can not only achieve the dust explosion limit test in a standard condition, but also realize the dust explosion limit test in an abnormal temperature condition, thereby ensuring the carrying out of the research work of the dust explosion limit test under a non-standard condition, so as to guide the chemical powder practical production, and to provide a technical support for safety production.

The invention relates to a fuel gas for welding cut that is environmental friendly and energy saving, in particular to a fuel gas that can substitute acetylene gas. The fuel gas comprises a propane gas, which is characterized in that synergist is added in certain proportion in the propane gas; the content of the propane gas is 97-99%; the content of the synergist is 5 per mill-1%, the content of the liquefiable foreign matter of gas is less than 2.5% by weight; the synergist is a mixed solution comprising combustion catalyst, smoke-removing agent, polymer degrading agent, solvent, solution assistant, and combustion assistant, etc.; the fuel gas is used as combustion gas in place of acetylene gas to weld and cut metals. The flame of the fuel gas is of high temperature, is free from reverse (return) combustion; the fuel gas is of very low explosion limit and low toxicity, free from harm to human bodies, of low comprehensive cost, high efficiency, is safe, environmental friendly and energy saving.