|Title of Invention||
"METHOD FOR THERMOCHEMICALLY NEUTROLISING HIGHLY TOXIC AGENTS"
|Abstract||The inventive thermochemically neutralising method consists in exposing a neutralisable agent to a multistage treatment in a high-temperature and high velocity gasflow by means of a thermochemical decomposition, an additional oxidation and by adding chemical reagents ensuring the total fulfilment of chemical reactions for obtaining final non-toxic compounds. At least at one treatment stage, the gasflow containing a neutralising agent is accelerated to a supersonic speed and afterwards is transformed into a subsonic flow in shock waves.|
|Full Text||The invention relates to the field of ecology and neutralizing five toxic agents relating to high hazard classes, namely: chemical weapons, pesticides, polychlorobiphenils, cyanides, etc. in free-flowing state (liquid, powder, and gas), and may be efficiently used in actions aimed to protect the environment from pollutions as well as in creating resource-saving technologies.
A method of thermochemical neutralization of highly toxic agents is known, which is described in RF Patent No. 2005519, A62 D 3/00, 1994 , According to this method, a neutralized agent is mixed with a high-temperature gas by treating the neutralized agent with a transonic-supersonic flow having the Mach number M = 0.9 - 2.0 at a temperature > 2,000°K, and afterwards the obtained mixture is burnt up in a reaction chamber at the excess oxidizer coefficient o A method for purifying gases from particulate pollutants is also known, which is described in RF Patent No. 2198721, B 01 D 47/06, 2001 . The said method includes mixing of water jets having velocities from 20 to 25 m/s with a purified gas for the formation of a supersonic two-phase equilibrium mixture, providing cross movements of water drops having sub-micron contaminations with the use of compression shock waves that are obtained by decelerating the said supersonic two-phase equilibrium mixture. Then, excess steam content of the purified gas is provided, excess steam containing in the gas is condensed, and condensed water is separated.
The inventive method enables to raise the quality of neutralization significantly. It is quantitatively expressed by decomposition and removal coefficient (DRC) which required level for traditional furnaces is 99.9. and for destruction of chemical weapons a coefficient of 99.9999 is required. The inventive method allows to reach the coefficient at least 99.9999.
The technical effect from using the inventive method consists in reducing dispersion of a thennochemically neutralized toxic agent, increasing combustion efficiency, eliminating formation ot secondary toxic chemical compounds.
The said technical effect is reached due to the fact that a neutralized agent is subject to multistage treatment in a high-temperature and high-velocity gas How having the Mach number M = OS -2.0 and a temperature at least 2.000°K. The said multistage treatment includes the step of thermochemical .
decomposition, the step of additional oxidation (burning-up) and the step of addition of chemical agents ensuring the total completeness of chemical reactions with the formation of final non-toxic compounds. At least at one step of the treatment a gas flow comprising a neutralized agent is at least once accelerated to a supersonic velocity and then, in compression shock waves, transferred to the field of subsonic flow. .
According to a preferable embodiment of the inventive method, the thermochemical decomposition step is carried out at a temperature from 2,500°K to 3,200°K.
According to another preferable embodiment of the inventive method, a gas flow comprising a neutralized agent is once accelerated to a supersonic velocity and then, in compression shock waves, transferred to the field of subsonic flow at each step of mermochemical decomposition, additional oxidation (burning-up) and chemical binding.
The substance of the treatment process forming the basis of the inventive method is that a thermochemical method is used for decomposing complex chemical substances and their mixtures at high temperatures, i.e., at temperatures in the range from 2,000°K to 3,500°K.
According to the nature of physical and chemical processes the thermal mode takes an intermediate level between the usual combustion or pyrolysis at temperatures from 1,200°K to 1,700°K and plasma neutralization of toxic agents at the typical temperature levels in the range from 5,000°K to 10,000°K. At the same time, the processes of forming a burning mixture and mixing combustion products in the inventive method differ significantly from traditional processes used in furnaces and plasma reactors.
The principal difference is that all physical and chemical processes neutralizing a toxic agent take place in a high-temperature gas flow having supersonic and close-to-sound velocities (M > 0,8).
The effect of forced acceleration of a high-temperature gas flow up to a supersonic velocity with the subsequent deceleration in compression shock waves down to subsonic velocities is that chemical interaction of good quality between chemically active media, one of them being a neutralized agent, is
According to a known method , a supersonic flow of two-phase medium is obtained only due to a sharp change in the acoustic properties during the formation of a two-phase mixture having a considerable content of the liquid fraction, namely water, wherein water does not interacts chemically, but performs the function of a volume filter. Compression shock waves result in braking up the water to droplets and sub-micron films and ensure cross movements of me water constituent with its sub-riiicron contaminants, which leans to capturing aerosols by me water.
In contrast to the known method , according to the inventive method a high-temperature flow is
accelerated to velocities in the range from 200 to 1,000 m/s, and a neutralized agent is destructed down to the molecular level together with the formation, after decelerating a uniform flow characterized by a high degree of equilibrium, fields of concentrated reaction products, which enables to increase the combustion completeness and practically eliminate the formation of secondary toxic chemical compounds.
A high efficiency and calorific intensity of processes taking place in the reaction chamber where heat release volume density is app. 6,000 MW/m3, thus hundreds of times exceeding the same figure for the best kinetic (with complete premixing) burner devices, ensures a very high completeness of physical and chemical transformations and mixing of reaction products. The reaction products temperature in the range from 2,000°K to 1,000°K is lowered by rapid cooling (at cooling rate being 106 degree/s), which additionally precludes the possibility of forming secondary toxic chemical compounds, especially dioxins and furans. At the final stage of separating gases of combustion from low-toxic acid-forming chemical compounds the combustion products, as characterized by a low content of harmful impurities, are removed to the atmosphere.
The invention will be further explained by its preferred embodiment with references to the appended drawing where:
FIG. 1 shows a block-diagram of a plant for carrying out the inventive method.
The invention will be explained by a specific embodiment of me neutralization device, the inventive method being characterized by a description of operation of the said device.
This illustrative description characterizes only one particular embodiment of the invention and may not be considered as the only one possible embodiment limiting all existing variants of its application.
A device for neutralizing highly toxic agents comprises a working gas source 1 being a high-temperature gas generator, a neutralized agent introduction system 2, a mixing device 3, a reaction chamber 4, a burning-up chamber 5, a chemical-binding chamber 6, and chemical agent feeding
A device 8 for flow velocity changing is arranged at the output of the reaction chamber 4 and the burning-up chamber 5. The device 8 for flow velocity changing may structurally form a part of the reaction chamber 4 or the burning-up chamber 5.
The final purification system 9, made, e.g., in me form of a scrubber, me recovery system 10, the solids neutralization and removal system 11, as well as the exhaust gas system 12 are arranged successively after the chemical-binding chamber 6 and are standard for this field of technology.
The device functions as follows.
A high-temperature gas generator acts as the working gas source 1. A working gas is accelerated in a nozzle up to supersonic velocities and forwarded to the mixing device 3. The neutralized agent introduction system 2 is used for feeding containers with a neutralized agent to the mixing device 3, or introducing a neutralized agent into the flow under a definite time profile, or injecting a neutralized agent into the working gas flow. The mixing device 3 is used for mixing a neutralized agent with the working gas and feeding the resulting mixture into the reaction chamber 4.
In the reaction chamber 4 the gas flow comprising the neutralized agent is accelerated, if it has not been accelerated yet, up to a supersonic velocity at a temperature in the range from 2,500°K to 3,500°K due to changes in the geometric characteristics at the corresponding organization of heat-mass exchange processes taking place during chemical reactions, and then the flow is transferred to the field of subsonic flow in compression shock waves. During the said steps a neutralized agent is destructed down to the molecular level in compression shock waves provided in the gas flow accelerated to high velocities.
Then the flow is fed into the burning-up chamber 5 where it reacts with an incoming oxidizer at a temperature app. 2,000°K. While being in the burning-up chamber 5, the gas flow comprising a neutralized agent may be also accelerated to a supersonic velocity and transferred in compression shock waves into the field of subsonic flow.
The flow from the burning-up chamber 5 is fed to the chemical-binding chamber 6. Depending on a particular chemical composition of the mixture, additional chemical agents are introduced into the chemical-binding chamber 6 through me feeding system 7 in amounts ensuring completeness of the oxidation processes and formation of stable substances which do not enter into side reactions during cooling.
Such non-toxic or low-toxic substances are subject to multistage treatment in the systems 9 and 10, then the gas phase is separated from the liquid phase and the solid phase, the latter being also passed through the multistage neutralization and removal system 11, and the gas phase is transferred to the exhaust gas system 12.
Thus, the achieved technical effect enables to significantly improve the neutralization quality of highly toxic agents and provide a DRC level necessary for destruction of chemical weapons.
1. A method for thermochemically neutralizing highly toxic agents, according to which a neutralized agent is subject to multistage treatment including the step of thermochemical decomposition of said neutralized agent, its subsequent burning-up and addition of chemical agents ensuring the total completeness of chemical reactions with the formation of final non-toxic compounds, characterized in that all said steps are carried out in a working gas high-temperature and high-velocity flow, and at least at one, or at each step of said treatment a gas flow comprising a neutralized agent is at least once accelerated to a supersonic velocity and then, in compression shock waves, transferred to the field of subsonic flow.
|Indian Patent Application Number||4667/DELNP/2006|
|PG Journal Number||15/2010|
|Date of Filing||11-Aug-2006|
|Name of Patentee||PAPUSHA ANTOLIY IVANOVICH|
|Applicant Address||U. MOSKOVSKAYA, 32-11, KHIMKI, MOSKOVSKAYA OBL., 141400, RUSSIA|
|PCT International Classification Number||A62D 3/00|
|PCT International Application Number||PCT/RU2005/000036|
|PCT International Filing date||2005-01-31|