RU2834026C1 - Device for taking atmospheric air samples in flight and dosing them into measuring device for determining total water content - Google Patents

Abstract

FIELD: sampling.

SUBSTANCE: invention relates to air sampling from aircraft. Disclosed is a device for sampling atmospheric air in flight, comprising a cylindrical housing with two spring-loaded end covers with damping and sealing gaskets attached to the axes, where the inner part of the cylindrical housing is hollow; on the lower part of the housing there are limiters for the movement of the covers relative to their axes with a pressure interrupter on one of the limiters; springs pressing the covers to the housing before sampling and returning them to the closed state after sampling are located outside the housing; covers are additionally fixed on the housing by screws passing through the holes in the covers and screwed into the cylinder walls; on each of the covers in the centre there are holes closed by rubber membranes fixed by bushings with plugs; inside the cylinder housing on the right side there is a piston tightly adjacent to the inner surface of one of the covers, the shank of which passes through a rubber membrane, a bushing and a plug with an end fixed on the cover by a lock nut, and on the same cover there is an additional hole plugged in flight by a screw with rubber gasket; device also includes a friction drive based on wheels with cables and an electric motor with remote control through the cover opening and closing control panel, on the shaft of which one end of the friction drive cable is wound, and the other ends of the cable are connected through carabiners to the covers; at that, the electric motor with the cables and the drive wheels is rigidly fixed on the bed, and the cylindrical body is fixed on the bed with a clamp with possibility of dismantling; wherein said device allows replacement of lock nut with elongated handle screwed into piston shank and left plug with needle for dispensing samples into measuring device for determination of total water content.

EFFECT: device provides higher accuracy of determination of total water content.

1 cl, 1 dwg

Description

The invention relates to a technique for taking samples of atmospheric air from on board an aircraft for testing total water content.

Accurate knowledge of the total water content (the total water content in different aggregate states) at various points in the atmosphere is necessary for the development of anti-icing systems and safe flight routes, as well as for conducting various R&D projects on icing protection and the development (calibration) of total water content sensors.

There are a large number of total water content sensors and methods for determining it, namely, Russian patents No. 2562476 of 10.09.2015 "Electrothermal method for determining the water content of an air flow", No. 2735908 of 10.11.2020 "Aircraft total water content sensor", No. 2758843 of 02.11.2021 "Method for determining the main parameters of the structure of airborne formations of clouds and fogs", US patent No. 7175136 of 13.02.2007 "Method And Apparatus For Detecting Conditions Conducive To Ice Formation", European patent EP2117926 of 26.12.2018 "Ice Rate Meter With Virtual Aspiration" ("Virtual Aspiration Icing Meter"), USSR Author's Certificate No. 1137381 dated July 29, 1983. "Device for Determining Rain Water Content", dissertation "Evaluation of Water Content Measurement Model 3000 Probe (WCM-3000) Using the NASA Impacts Dataset", Jennifer Rose Moore, 2023 ("Evaluation of the WCM-3000 Water Content Measurement Model Based on NASA Impacts Datasets", https://commons.und.edu/theses/5685) and others. They are based either on the cooling effect of a calibrated plate, or on the conversion of a particle flow into a vapor state and measuring the concentration of water vapor in the flow. Their advantages include continuity of action, but their precise calibration within the framework of the proposed methods and devices is impossible and is not performed. Accurate knowledge of the total water content in the flow approaching an aircraft, which can be used both for calibrating sensors and independently for determining reference values of water content, is possible only after correct sampling of air from the flow - without changing its parameters - with subsequent analysis of the total water content in it.

There are known devices for collecting and storing air samples in the form of glass ungraded gas pipettes with two one-way taps, manufactured according to GOST 18954-73 "Glass device and pipettes for collecting and storing gas samples", as well as similar devices made in the form of canisters, described in the ASTM standard (2021): "Standard Test Method for Determination of Volatile Organic Chemicals in Atmospheres (Canister Sampling Methodology)", West Conshohocken, PA, American Society for Testing and Materials (ASTM Standard D5466-21). In this case, a canister with a shut-off valve is used either pre-evacuated, or sampling is performed by gas exchange (purging the canister with a large amount of air), which is not suitable for testing water content due to possible condensation and freezing of moisture on the walls of the canister.

The NP-ZM sampler pump is known for collecting single samples of gas-air mixtures for the purpose of subsequent determination of their chemical composition using indicator tubes in accordance with GOST R 51712-2001, GOST 12.1.014-84, GOST R 51945-2002 - Russian Federation Patent No. 89701 of 10.12.2009 "Hand pump - sampler", the disadvantage of which is the absence of a shut-off device and the unintended nature of the vacuum it creates for long-term maintenance due to significant air leakage along the piston seal.

Also known are a device for collecting water samples from reservoirs in the air - US Patent No. 4744256 of 17.05.1988 "Airborne Water Sampler Device", which is a cylinder with simultaneously closing and opening opposite holes using a system of ball valve cables, and a container with double opening for collecting liquid samples - US Patent No. 7178415 of 29.02.2007 "Dual-Opening Sample Containers, Fluid Sampling Device and Method of Using Same", where the container is closed using a trigger only after collecting a water sample. In both devices, the principle of isokinetic flow is violated, and the complexity of the designs does not allow them to be used for collecting air samples on the wing or outer skin of an aircraft.

There are known metal vacuum tanks with electromagnetic valves, assembled in several pieces into containers, given in departmental methodology No. 12-16-111, developed by JSC "Gromov Flight Research Institute". However, these devices do not provide constant vacuum control, which may distort the results of subsequent analysis of water content, and the principle of isokinetic sampling is not ensured, which does not guarantee that all the water (especially large crystals) gets into the sampler.

The closest to the claimed device is the sampling device described in the Russian Federation patent for invention No. 2782051 dated October 21, 2022 "Device for sampling atmospheric air in flight to determine the total water content". However, experiments have shown the shortcomings of this design: the cylinder covers are not secured, additional elements are located inside the cylinder that distort the air flow, the cover drive has a complex mechanical lever design that can slow down in icing conditions, and there is no possibility of directly pumping the sampled air into the analytical device, since this design does not have dispenser functions.

The technical result, which the claimed device is aimed at achieving, consists in increasing the accuracy of determining the total water content by eliminating the above-mentioned shortcomings of the prototype. Additional design elements allow using the newly developed device as a dispenser for direct transfer of the selected sample to the measuring device.

In order to achieve this technical result, the device for sampling atmospheric air in flight comprises a cylindrical body with two spring-loaded end caps with shock-absorbing and sealing gaskets attached to axles, characterized in that the inner part of the cylindrical body is made hollow with the possibility of ensuring isokineticity and the absence of flow distortion during the process of sampling atmospheric air; on the lower part of the body there are limiters for the movement of the caps relative to their axes with a push-button interrupter on one of the limiters, ensuring the cessation of the power supply to the drive electric motor and the simultaneous closing of the caps after the completion of sampling and its aliquot and preventing the blowing out of the sample taken; springs pressing the caps to the body before sampling and returning them to the closed state after sampling are located outside the body; The covers are additionally fixed to the body with screws that pass through the holes in the covers and are screwed into the walls of the cylinder, ensuring the tightness of the cylinder cavity and the safety of the sample after sampling.

Each of the covers has holes in the center that are closed with rubber membranes, fixed with bushings with plugs.

Inside the cylinder body, on the right side, there is a piston, tightly adjacent to the inner surface of one of the covers, the tail of which passes through a rubber membrane, a bushing and a plug with an end secured to the cover with a lock nut, and on this same cover there is an additional hole, sealed in flight by a screw with a rubber gasket.

The device also contains a friction drive based on wheels with cables and an electric motor with remote control via a control panel for opening and closing the covers, on the shaft of which one end of the friction drive cable is wound, and the other ends of the cable are connected via carabiners to the covers; in this case, the electric motor with cables and drive wheels are rigidly fixed to the frame, and the cylindrical body is fixed to the frame with a clamp with the possibility of dismantling.

Moreover, the device is designed with the possibility of replacing the lock nut with an extended handle screwed into the piston tail, and the left plug with a sleeve with a needle for dosing samples into a measuring device for determining the total water content.

Fig. 1 shows a sketch of the proposed device for sampling atmospheric air in flight to determine the total water content.

The device selected as a prototype contains: a cylindrical body with two spring-loaded end caps mounted on axles with shock-absorbing and sealing gaskets,

The proposed device (Fig. 1) contains a cylindrical body 1 with two covers 2, fastened on axles 3 and equipped with rubber gaskets 4. With the help of springs 5, the covers are tightly pulled to the ends of the cylinder and in ground conditions are fixed with screws 6. In the center of the covers there are openings, closed with rubber membranes 7 and fastened by screwing in bushings 8. The left bushing in flight is closed with a plug 9, which after selection in ground conditions is replaced with a bushing with a needle 10.

Inside the cylinder, on the right side, there is a piston 11, tightly adjacent to the inner surface of the cover, the tail of which passes through a rubber membrane and a plug bushing with a lock nut 12 fixed at the end, which can be replaced in ground conditions with an extended handle 13, screwed into the tail of the piston. Limiters 14 are fixed at the bottom edges of the cylinder, a push-button interrupter 15 is installed on the left limiter, which, when the covers are opened, stops the supply of electricity to the engine 16, which is switched on from the control panel 17. In this case, cables 18, attached with carabiners 19 to the covers, through the wheels of the friction drive 20 begin to wind onto the shaft 21 of the engine, ensuring the opening of the covers to the limiters. The engine and wheels are fixed on the frame 22. The cylindrical body is also fixed to the frame using a clamp 23. In ground conditions, after assembling the cylinder into a syringe dispenser, the screw with rubber gasket 24 is unscrewed from the right cover.

Operation of the device

The device operates as follows. In the inoperative state, the cylindrical body 1 with the electric motor 21 switched off (no power is supplied from the remote control 17) is tightly closed by the tension of the springs 5 with the covers 2 with gaskets 4 attached to the axles 3. When power is supplied to the electric motor, the cables 18 are wound through the wheels 20 onto its shaft, ensuring the opening of the covers attached to them with carabiners 19. When the open covers rest against the limiters 14, the circuit breaker 15 is triggered. The engine is switched off, and the covers are closed by the springs 5.

After sampling, the sampler is dismantled from the frame on board the aircraft. The upper part of the covers is fastened to the cylinder with screws 6. The sampler is sent to the laboratory, where it is thermostatted at room temperature (with high water content, a thermostat with an elevated temperature can be used, which is selected experimentally) for at least 3 hours. Then, changes are made to the design, allowing this device to be used as a dispenser for direct transfer of the collected sample to the measuring device. Instead of the left plug 9, a sleeve with a needle is screwed on, piercing the membrane 7. The lock nut 12 is removed, and an extended handle 13 is screwed into the axis of the piston 11. Screw 24 is unscrewed to allow air to enter the above-piston space when moving the piston 11 by pressing the handle 13, due to which the air sample is introduced into the analytical device (the evaporator of the gas chromatograph), where, according to existing methods, it is accurately analyzed for water vapor content.

In combination with continuously operating total water content sensors, such a device can provide high accuracy in measuring the total water content of the atmospheric air on the surface of an aircraft, providing, among other things, the ability to calibrate other total water content sensors installed on the aircraft.

Claims (6)

A device for sampling atmospheric air in flight, comprising a cylindrical body with two spring-loaded end caps with shock-absorbing and sealing gaskets attached to axles, characterized in that the inner part of the cylindrical body is made hollow with the possibility of ensuring isokineticity and the absence of flow distortion during the process of sampling atmospheric air; on the lower part of the body there are limiters for the movement of the caps relative to their axes with a push-button interrupter on one of the limiters, ensuring the cessation of the power supply to the drive electric motor and the simultaneous closing of the caps after the completion of sampling and its aliquot and preventing the blowing out of the sample taken; springs pressing the caps to the body before sampling and returning them to the closed state after sampling are located outside the body; the covers are additionally fixed to the body with screws that pass through the holes in the covers and are screwed into the walls of the cylinder, ensuring the tightness of the cylinder cavity and the safety of the sample after sampling; each of the covers has holes in the center that are closed with rubber membranes, fixed with bushings with plugs; inside the cylinder body on the right side there is a piston, tightly adjacent to the inner surface of one of the covers, the tail of which passes through a rubber membrane, a sleeve and a plug with an end secured to the cover with a lock nut, and on this same cover there is an additional hole, sealed in flight by a screw with a rubber gasket; the device also contains a friction drive based on wheels with cables and an electric motor with remote control via a control panel for opening and closing the covers, on the shaft of which one end of the friction drive cable is wound, and the other ends of the cable are connected via carabiners to the covers; in this case, the electric motor with cables and drive wheels is rigidly fixed to the frame, and the cylindrical body is attached to the frame with a clamp with the possibility of dismantling; wherein the device is designed with the possibility of replacing the lock nut with an extended handle screwed into the piston tail, and the left plug with a sleeve with a needle for dosing samples into a measuring device for determining the total water content.

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