65 results about "Concentric cylinder" patented technology

The present invention relates to the technical field of coastal engineering, and disclosed is a method for evaluating a radiation hydrodynamic force for a concentric cylindrical structure, comprising the following steps: S1, coordinate system establishment: establishing a cylindrical coordinate system orθz and a Cartesian coordinate system oxyz by taking the intersection of the center of a concentric cylindrical structure and a still water surface as the origin, where the z-axis is vertically upward; S2, flow field division: dividing the entire flow field into an outer domain and an inner domain; S3, perforated boundary condition assumption; S4, determining radiation velocity potentials of the inner domain and the outer domain by means of governing equations and boundary conditions; and S5, by means of the expressions of velocity potential functions of the inner and outer domains, determining first-order radiation forces, added masses and damping coefficients generated by the vibration of an inner cylinder and an outer cylinder. The method takes into account both the effects of seismic and radiation hydrodynamic forces, provides accurate structural response prediction, fills the technological gap in the field of seismic analysis of concentric cylindrical structures as breakwater units, and provides a reliable basis for engineering design.

The invention discloses an annular plate-containing concentric cylinder wave diffraction hydrodynamic force evaluation method, an annular plate-containing concentric cylinder comprises an inner cylinder, an outer cylinder and a perforated annular plate arranged between the inner cylinder and the outer cylinder, the method is characterized by comprising the following steps: establishing a cylindrical coordinate system at the intersection point of a still water surface and the center of the cylinder, and the z axis is vertically upward; the drainage basin is divided, the outer area of the outer cylinder is set as the outer area, the annular space area between the inner cylinder and the outer cylinder is set as the inner area, and the inner area comprises the area above the annular plate and the area below the annular plate; setting an opening boundary condition, defining a porous effect parameter of the opening annular plate as sum, and setting a related speed potential boundary condition; deriving an outer domain velocity potential and an inner domain velocity potential, and coupling velocity potential solutions through inner and outer domain boundary conditions; and solving the hydrodynamic load and the free surface elevation according to the velocity potential. The invention provides a wave diffraction hydrodynamic force evaluation method without a plurality of characteristic roots for a concentric cylinder structure containing a single-layer horizontal perforated ring plate. According to the method, the inner domain is further divided into two drainage basins, so that the trouble of a plurality of feature roots is avoided, a brand new feature function is established, and the solving efficiency can be greatly improved.

The invention discloses a spiral-flow type riser reactor with an annular space structure. The reactor sequentially comprises a feeding section, a reaction section and a reaction stopping section from bottom to top, and the three sections respectively adopt a concentric cylindrical barrel, a concentric conical barrel and a hollow straight barrel. Raw material and catalyst feeding pipes are both positioned at the feeding section and are tangent to the outer cylinder body according to the same rotating direction, and rotational flow is generated in an annular gap between the inner cylinder and the outer cylinder. The catalytic cracking device is mainly used for preparing low-carbon olefin by taking heavy oil, wax oil, low-carbon alkane gas and the like as raw materials. According to the spiral-flow type riser reactor disclosed by the invention, raw materials and a catalyst can be uniformly mixed, and backmixing is basically eliminated; and a relatively large catalyst-oil ratio and strict reaction time can be adopted, so that the process conditions required for producing low-carbon olefins by catalytic cracking can be met, and compared with the conventional hollow cyclone reactor, the hollow cyclone reactor has obvious advantages.

The invention discloses high-thermal-conductivity fiber toughened fluorescent ceramic as well as a preparation method and application thereof, and aims to solve the problems of brittle fracture and thermal quenching of traditional fluorescent ceramic. According to the method, a pre-strain programmable 4D printing technology is adopted, and aluminum nitride (AlN) short fibers and carboxymethyl cellulose are self-assembled to form a natural concentric cylinder microstructure, so that the toughness and the mechanical property of the ceramic are enhanced. The strain distribution of the rubber film in a tensile state is simulated through finite element analysis, and the stress direction and the deformation control of a key area are optimized. Pre-strain is applied to the rubber film, and a fluorescent ceramic biscuit is printed on the surface of the rubber film; after the stress is released, the ceramic body spontaneously deforms into a hollow hemispherical structure. A rubber substrate is removed through high-temperature sintering, and the fluorescent ceramic with high mechanical strength and high thermal conductivity is obtained. The bending strength of the fiber-toughened fluorescent ceramic reaches 500-600 MPa, and the fracture toughness is improved to 9-11 MPa.m / , so that the fiber-toughened fluorescent ceramic is obviously superior to the traditional fluorescent ceramic.

The invention relates to the technical field of alloy casting, in particular to a magnetic particle reinforced alloy electromagnetic centrifugal casting system and a working method thereof. The electromagnetic centrifugal casting system comprises an electromagnetic centrifugal casting device, a driving device, an electromagnetic device and a vacuum device. The electromagnetic centrifugal casting device comprises a shell and a concentric cylindrical mold, the concentric cylindrical mold is rotationally installed in the shell and comprises an outer barrel and an inner barrel, the outer barrel is connected to the outer side of the inner barrel in a sleeving mode, a containing cavity is formed between the shell and the outer barrel, and a working cavity is formed between the outer barrel and the inner barrel; the driving device is used for driving the concentric cylindrical mold to rotate, the electromagnetic device is arranged in the containing cavity in a radioactive mode and used for generating a magnetic field, and the vacuum device is connected with the shell and used for vacuumizing. According to the invention, the problems of particle aggregation and uneven distribution in the traditional process are solved, and the mechanical property and production efficiency of the composite material are obviously improved.

A welding spatter protection device has a support structure, a movable structure delimiting a first internal cavity by internal side walls and movable by a first actuator between a lowered position, in which the first internal cavity is placed astride a welding zone, and a raised position, in which the first internal cavity is moved away from the welding zone, and a cleaning system having a scraper. Two second internal side walls interconnect two first internal side walls defining two concentric cylindrical surfaces. The scraper is connected to the movable structure by a support arm actuatable by a second actuator. Circumferential ends of the concentric cylindrical surfaces at an inlet mouth and at an internal stop position are radially aligned so that the scraper is always in contact with the concentric cylindrical surfaces, oriented so that a radially outermost cylindrical surface extends beyond the bottom wall, defining a shielding appendage.

The utility model discloses a kind of energy storage systems, specifically in the energy storage technical field, including spherical water tank, spherical water tank is equipped with vortex heat exchanger, the inner end of vortex heat exchanger is communicated with connecting pipe, and another end of connecting pipe is communicated with the top of spherical water tank, the top of spherical water tank is penetrated with first conveying pipe, the top of first conveying pipe is communicated with first concentric cylinder, and first conveying pipe and the center tube of first concentric cylinder are directly communicated, first concentric cylinder is equipped with heat absorption tower shell, the top opening of heat absorption tower shell is inserted with second concentric cylinder, first concentric cylinder and second concentric cylinder are staggered and inserted and form flow channel by heat absorption tower shell axial flow to heat absorption tower shell side wall, first concentric cylinder is fixedly connected with heat absorption tower shell by skirt with bottom setting through-hole, the outer end of vortex heat exchanger is communicated with second conveying pipe, and second conveying pipe is communicated with the bottom of heat absorption tower shell, and the energy storage system is under the common heat preservation of heat preservation soil layer and heat preservation layer in soil, hot water can be heat preserved for several days.

An apparatus fixed to a water vehicle to produce electric energy has a turbine rotor supported under the water surface in a horizontal operation position and to it fixed first axis to transfer the rotation motion from the rotor and in which apparatus the rotor has been supported and adapted into with it same centered cylinder that has been fixed to the frame with vertically to it fixed joint that is situated a vertical distance (a) from the rotor and adapted to turn in relation to the frame that has been fixed to the water vehicle round the joint axis and to settle into the direction of the water flow by its power and where the first part of the second axis has been adapted same centered with the joint axis and the first and the second axis have been connected to each other with a rotation movement direction changer when the horizontal rotation of the first axis has been adapted to change into a vertical rotation movement in the first part and the second axis has been connected to a generator to transfer the rotation movement into it and the generator has been connected to a battery to store the generated electric energy to it.

1. Name of the design product: Main body of an electric nail care device. 2. Use of the design product: This design product is used for nail care. 3. Design key points of the design product: Lies in the shape. 4. Picture or photo that best shows the design key points: Combined perspective view. 5. The nail care device of Component 1 of this design product is cylindrical, with a tip at one end and connected to the power cord at the other end. The nail care device is composed of a concentric cylinder and a cone, and the radius of the cone gradually decreases from the power cord connection to the tip. Other views of Component 1 are omitted. 6. Other circumstances that need to be explained - Component description: This design product is a component product. Among them, Component 1 is the nail care device; Component 2 is the control box, which is connected to the nail care device via the power cord and is used to control the operation of the nail care device. 7. Other circumstances that need to be explained - Other explanations: The design protected by this application is a partial design. Among them, the solid lines indicate the parts that are claimed, and the dashed lines indicate the parts that are not claimed. The power cord in Component 1 of this design product is a slender item, and the two parallel double-dashed lines therein indicate the omitted parts.

The utility model discloses an online injection device for preventing filler hardening in a blast furnace gas fine desulfurization system, which is characterized in that a reactor consists of a plurality of layers of concentric cylinders and is divided into an outer cylinder, a filler layer outer sieve plate and a filler layer inner sieve plate from outside to inside; the air supply source is connected with the supporting steel pipe; a plurality of supporting steel pipes are arranged on the outer side of the packing layer outer sieve plate and the inner side of the packing layer inner sieve plate in the circumferential direction at intervals and attached to the side walls of the packing layer inner sieve plate and the packing layer outer sieve plate. A plurality of short blowing pipes are vertically arranged on each supporting steel pipe at intervals, penetrate through the side wall of the outer sieve plate of the packing layer or the side wall of the inner sieve plate of the packing layer and extend into the packing layer. The supporting steel pipe is arranged in the filler layer, and the filler layer is inflated, so that the strength of the filler layer can be increased, nitrogen injection can be realized, the operation is simple, the problem of hardening of the filler in the tower body can be effectively solved, and the service life of the filler is prolonged.

The present invention relates to the technical field of friction and wear test, and particularly to a mating method and device for reciprocating friction and wear on a circumferential surface. The connection method of cross - crossed concentric cylinders is adopted to realize the installation of the specimen on the circumferential surface and a conventional testing machine, and then a friction pair is formed with a ring specimen or a disc specimen. When friction occurs, a reciprocating linear relative motion forms friction and wear. In the friction pair, the sample on the circumferential test surface is connected to the pin specimen fixture of the reciprocating friction testing machine through a cross - concentric adapter block and is clamped and fixed by a locking screw. The ring specimen or disc specimen for friction is connected to the testing machine by an installation table with a V - shaped positioning groove. Both the application of load and the reciprocating relative motion adopt the conventional reciprocating test method of the existing testing machine. The friction pair method and device of the present invention can solve the problem of evaluating the circumferential surface in the friction and wear test, ensure the smooth movement of the test process and the reliable contact of the specimen to be tested, and expand the application of the reciprocating friction and wear testing machine.

The utility model discloses a leakproof sealing structure of a pneumatic power mechanical element, which comprises an air cylinder, an air inlet and an air outlet, the air inlet and the air outlet are arranged on two sides of the air cylinder, a lower concentric cylinder is embedded and fixed in each of the air inlet and the air outlet, an upper concentric cylinder is in threaded connection with the lower concentric cylinder, a connector is fixedly connected onto the upper concentric cylinder, and the connector is in threaded connection with the lower concentric cylinder. A clamping plate is connected to the side of the connector in a clamped mode, a locking screw rod is connected to the surface of the clamping plate in an inserted mode, an air pipe is fixedly connected to the connector, and a throttling valve and an electromagnetic valve are arranged on the air pipe. The upper cylinder and the lower cylinder which are concentric are arranged at the air inlet and the air outlet of the air cylinder, air can be prevented from leaking from the air inlet and the air outlet of the pipeline and the air cylinder, meanwhile, the clamping plate and the locking screw are arranged at the pipeline connector, the connector for fixing the pipeline can be further reinforced, the problem that the connector shakes under the impact of the air is solved, and the service life of the air cylinder is prolonged. Therefore, the pneumatic power mechanical element has the leakproof sealing effect.

The invention provides a graphite core column for high-temperature and high-pressure synthesis of high-thermal-conductivity diamond and a preparation method, the graphite core column is of a three-layer concentric cylinder structure, and the graphite core column is sequentially composed of a nitrogen removal core layer, a catalytic reaction layer and a sealing pipe layer from inside to outside. The nitrogen removal core layer forms an active defense system, Ti / Zr elements located in the core react with nitrogen to produce stable nitrides, nitrogen impurities are firmly captured and fixed to the nitrogen removal core layer, and the diamond growth environment of the catalytic reaction layer is purified; and the catalytic reaction layer is formed by mixing a Ni-Mn-Cu ternary catalyst and graphite. The catalyst system ensures that the dynamic processes of dissolution and precipitation of the carbon source in the catalyst are consistent, and stable growth of diamond single crystals is facilitated; the outer-layer sealing pipe graphite is used for sealing an internal reaction system and preventing external pollution. The three layers of structures perform their own functions and cooperate with one another, impurity removal, growth and pressure maintaining are integrally designed, and the system solves the three core problems of nitrogen pollution, uneven growth and pressure fluctuation in synthesis of the high-thermal-conductivity diamond.

This invention relates to the field of angular contact ball bearing processing technology, and more particularly to a high-precision assembly fixture specifically designed for angular contact ball bearings. It includes an assembly box, an inner cylinder positioning assembly, an outer cylinder positioning assembly, and a temperature-conducting assembly. This invention utilizes the principle that semiconductor materials absorb and release heat at their two ends when energized, and, in conjunction with the lifting and rotating of the temperature-conducting assembly with a concentric cylinder structure, achieves flexible switching between cooling and heating. By attaching the heating / cold ends of the temperature-conducting assembly to the temperature-conducting platform, the temperature of the angular contact ball bearing is specifically adjusted, and the principle of thermal expansion and contraction is used to control the installation space. During assembly, the inner and outer cylinder positioning assemblies, working together, not only fix and limit the inner and outer cylinders respectively, but also automatically complete the installation of the balls. The installation methods are diverse, the process is highly controllable and automated, and it meets the high-precision requirements of different types of angular contact ball bearings.

The utility model discloses an energy-saving type heating network heater, and particularly relates to the technical field of heating network heaters, the energy-saving type heating network heater comprises a tank body, a hollow end cover is installed at an opening of the tank body, and a fixed concentric cylinder and a movable concentric cylinder are inserted in a staggered mode to divide an inner cavity of the tank body into a reciprocating zigzag flow channel extending from the axis to the annular outer wall; a plurality of heat exchange pipes extending in the same direction as the reciprocating zigzag flow channel are installed in the reciprocating zigzag flow channel, one ends of the heat exchange pipes jointly penetrate through the hollow end cover and jointly communicate with an integrated ring, the other ends of the heat exchange pipes jointly communicate with an integrated plug, a separator is fixedly embedded in the tank body, and the integrated plug communicates with an inner cavity of the separator; according to the heat exchanger, the flowing distance of a heating medium in a shell pass is prolonged, and meanwhile, the heat exchange efficiency is high when the heating medium and cold water oppositely flow in the tank body.

Broad volumetric range pipettes with multi-tiered pipette tip holder and ejection assemblies and methods of using such pipettes are disclosed herein. These pipettes typically include a concentric cylinder arrangement with each outer cylinder configured for contacting and dislodging a pipette tip attached to the tip holder portion of the immediately adjacent inner cylinder. In this manner, different sized pipette tips can be used on a single device. In addition, a locking mechanism is described for locking the large tip holder into a downward position to minimize the extension of the small tip holder and thereby enabling attachment of large, filtered pipette tips and reducing / eliminating the risk that the liquid being transferred will contaminate the pipetting device.

A wind powered turbine is disclosed that comprises two concentric cylinders. The first cylinder is located within the perimeter of the second cylinder. Both the first cylinder and the second cylinder comprise a plurality of blades. The first cylinder and its blades move in response to wind activity. The second cylinder and its blades do not move when the first cylinder and its blades are moving. The curvature of the blades of the first cylinder and the curvature of the blades of the second cylinder are in different directions with respect to each other.

The present invention belongs to the field of wireless communication, and more specifically, relates to a low-loss leaky coaxial cable and a manufacturing method thereof. The leaky coaxial cable includes an inner conductor, a composite insulation layer, an outer conductor, and a sheath layer coaxially arranged in sequence, and each layer forms a concentric cylindrical structure centered on the axis. By roughening the outer surface of the inner conductor and the outer surface of the outer conductor of the leaky coaxial cable respectively, the contact between the inner conductor and the insulation layer and the contact between the outer conductor and the sheath layer are improved. At the same time, the solid inner skin layer originally used for bonding the inner conductor and the insulation layer is omitted, which not only improves the signal transmission performance but also reduces the transmission loss. Compared with existing products, the leaky coaxial cable with the inner and outer conductor surfaces treated in the present invention optimizes the attenuation index by 2.6% to 5.8% in the multi-frequency band from 900 MHz to 2700 MHz on the premise of meeting the requirements of the adhesion between the insulation layer and the inner conductor, the standing wave, and the insulation dielectric strength test.

The invention provides a high-strength flame-retardant composite insulator device. The high-strength flame-retardant composite insulator device comprises a gradient functional composite core rod, an umbrella skirt group, an upper-end fitting and a lower-end fitting, the composite core rod with the gradient function is of a three-layer concentric cylinder structure and comprises an inner layer, a middle layer and an outer layer. The inner layer is formed by compounding E-glass fibers and epoxy resin; the middle layer is an epoxy resin matrix, and phase change microcapsules are uniformly dispersed in the middle layer; the outer layer is an epoxy resin matrix doped with a mixed filler of graphene and boron nitride; the gradient functional composite core rod is of a three-layer concentric structure, the inner layer is E-glass fiber / epoxy resin, and high tensile strength is guaranteed; the middle layer contains phase change microcapsules, so that heat energy absorption and temperature control buffering are realized; the outer layer is doped with the graphene and boron nitride mixed filler, so that the composite insulator has high thermal conductivity and intrinsic flame retardance, combustion is effectively inhibited, heat dissipation is accelerated, and the contradiction that a traditional insulator is not flame-retardant if being strong and is weak in flame retardance if being strong is solved.

The application discloses a kind of simulation near wellbore radial layered permeability loss combined formation physical model and preparation method thereof.The method uses sand type 3D printing technology, with furan resin and amorphous silica sand as raw material, and is integrally formed to prepare combined formation model containing prefabricated wellbore structure, which is composed of inner / middle / outer three independent concentric cylinder structures, realizes the simulation of permeability loss of each part of formation by vacuum permeation modifier post-processing.The inner / middle / outer three independent concentric cylinder structures are 3D printed according to the designed inner and outer diameter size, and to ensure the smooth assembly of three parts of structure, the inner diameter size of each part of structure is designed to reserve 0.5-1mm deformation redundancy (deformation joint).In the vacuum permeation post-processing process, nanometer silicon dioxide solution is used as modifier, vacuum saturation device is used for vacuum permeation treatment of component, and by changing the negative pressure holding time (5-10min) of each cycle and the vacuum saturation cycle number of each component, the independent and quantitative control of permeability of different structure layers is realized, so as to obtain the combined formation model with radial layered permeability difference from wellbore outward.The method can accurately and quantitatively prepare simulation near wellbore formation radial heterogeneous permeability loss, and has the advantages of flexible operation, low cost and strong controllability, which can provide reliable model preparation method for physical simulation of oil and gas reservoir development and underground pollutant migration.

Device for mechanical separation of distillate fractions has for a novelty a rotating vessel (104) mounted concentrically with a vertical pipe (102), between an overflow ring (103) and a segmented collector vessel (105), wherin the rotating vessel (104) contains two concentric cylindrical walls and a bottom in the form of a circular ring connected to a distillate outlet (109). The rotating vessel (104) can rotate around the vertical tube (102) axis. The collector vessel (105) is located below the rotating vessel (104), and fixed to the vertical pipe (102) and consists of several segments separated by partition walls (108), where each segment has an independent distillate drain (109) which is connected to the storage tanks. The device also includes an inlet (101), the overflow ring (103) and a discharge valve (110). The distillate is fed into the vertical tube (102), where it is raised and poured over the overflow ring (103), and then collected in the rotating vessel (104) which direct the liquid to the corresponding segment of the collector vessel (105).

The invention belongs to the technical field of shock tube combustion monitoring, and relates to a shock tube large-size annular visual structure light path correction device which comprises a large-size annular window and a correction lens, the large-size annular window is in a concentric cylinder shape, the correction lens is in a tile shape, and the large-size annular window and the correction lens are both made of high-temperature-resistant transparent materials; the correction lenses are arranged in pairs, the correction lens pairs are axially symmetrically arranged on the two sides of the outer cylindrical surface of the large-size annular window, and the large-size annular window is used for visually monitoring the combustion process in the large-size annular window; according to the invention, the flame light beams diverged in the shock tube are collimated, so that the flame light beams enter the high-speed schlieren camera in parallel, and the transient phenomenon responsiveness and accuracy of camera shooting in the combustion process are improved.

Disclosed are a rare earth rotary target and a preparation method therefor. The rare earth rotary target includes a back tube and at least one rare earth target tube welded outside of the back tube; and the back tube and the rare earth target tube are welded via an intermediate welding layer. The intermediate welding layer includes a metal indium solder and an aluminum sheet arranged in the metal indium solder. The aluminum content in the intermediate welding layer is 3-10 wt. %. The back tube, the aluminum sheet, and the rare earth target tube are concentric cylindrical structures. According to the technical solution of the present application, the melting point of the solder is increased, thus achieving the purpose of improving the sputtering power density and a target utilization rate of rare earth rotary targets.

The invention relates to a heat exchanger (3) with two fluid circuits, comprising: - a shell (30) formed by two concentric hollow cylinders (31, 32), having a central axis (X), and defining therebetween an annular space; - plates (300) each having a straight cross-section perpendicular to the central axis X, in the form of a portion of the involute of a circle or of a curve having a radius of curvature that increases from the inner cylinder towards the outer cylinder and close to an involute of a circle, the plates each connecting the two cylinders of the shell and being parallel to one another in the annular space, while delimiting therebetween, on either side of the same plate, a channel (33) of one of the two fluid circuits, referred to as the first circuit and, within each of the plates, a channel (34) of the other one of the two fluid circuits, referred to as the second circuit.

Heat exchanger with at least two fluid circulation circuits, with a jacket of two concentric cylinders between which are arranged plates of general involute shape; Use in a nuclear reactor with molten liquid salt(s).The invention relates to a two-circuit fluid heat exchanger (3) comprising: - a casing (30) formed by two concentric hollow cylinders (31, 32) with a central axis (X), defining an annular space between them; - plates (300), each having a straight cross-section perpendicular to the central axis X in the form of a portion of an involute of a circle or a curve with a radius of curvature increasing from the inner cylinder to the outer cylinder and close to an involute of a circle, the plates each connecting the two cylinders of the casing and being parallel to each other in the annular space, delimiting between them, on either side of the same plate, a channel (33) of one of the two fluid circuits, called the first circuit, and within each of the plates a channel (34) of the other of the two fluid circuits, called the second circuit. Figure for the abstract: Fig. 7A.

A wind powered turbine is disclosed that comprises two concentric cylinders. The first cylinder is located within the perimeter of the second cylinder. Both the first cylinder and the second cylinder comprise a plurality of blades. The first cylinder and its blades move in response to wind activity. The second cylinder and its blades do not move when the first cylinder and its blades are moving. The curvature of the blades of the first cylinder and the curvature of the blades of the second cylinder are in different directions with respect to each other.

The application discloses a vertical radial flow cold accumulator, which comprises a vertical shell, the bottom of the shell is provided with supporting feet, wherein the inside of the shell is provided with a concentric cylinder which is arranged concentrically with the shell and comprises two cylinders with a certain interval; the concentric cylinder divides the inside space of the shell into a flow distribution channel, a filling layer and a flow collecting channel from outside to inside along the radial direction of the shell, a buffer cavity which is communicated with the flow distribution channel is formed between the bottom of the concentric cylinder and the bottom of the shell; the filling layer is respectively communicated with the flow distribution channel and the flow collecting channel in the radial direction, the inside of the filling layer is filled with energy storage medium for forming a bed layer and a filler seal which is arranged on the top of the energy storage medium and used for preventing airflow short circuit after the energy storage medium is settled; a flow guide cone which is gradually reduced in diameter along the axial direction is arranged in the flow distribution channel or the flow collecting channel. The application can make the bed layer have smaller resistance and more uniform airflow distribution, improve the effective utilization rate of space and energy storage performance, and is favorable for the large-scale development of the cold accumulator.

The invention provides a functional filter element structure and a preparation method thereof. The filter element structure sequentially comprises a first filter layer and a second filter layer from inside to outside, the thickness of the first filtering layer is 10 to 100 mm; the thickness of the second filter layer is 10 to 100 mm; water sequentially passes through the second filter layer and the first filter layer to be filtered; the first filter layer is a functional filter layer; the second filter layer is a coarse filter layer; and the functional filter layer contains a target functional filter material for filtering specific pollutants. The mass ratio and spatial distribution (concentric circle / up-down / left-right structure) of the activated carbon and the lead removal filter material are accurately controlled through the separation mold, so that the effective contact area of the lead removal layer is increased. The concentric cylinder structure in the embodiment 1 still keeps the removal rate of 98% in a 10,000 liter limit test, and it is proved that the saturation threshold value of the filter material is increased to several times that of a conventional product.

A vent assembly, including a backplate having plurality of concentric cylinders arranged in an order of decreasing diameter, such that the concentric cylinders are separated by score lines and at least one of the cylinders is recessed from the backplate, and a vent flapper. The assembly may include a tube configured to attach to one of the cylinders and one or more tube stoppers to prevent the tube from being over inserted. The assembly may include a face plate, a tooth formed on the backplate, and a tooth receiver is formed on the face plate. The score lines may be dual-sided score lines. The assembly may include the vent flapper having one or more air intake openings formed within the vent flapper, such that the air intake openings allow air to flow both in and out.

The invention discloses a textile thermal insulation performance test system and method, and the system comprises a sealed test cabin which is used for simulating different environments; the concentric cylinder testing structure is located in the middle of the closed testing cabin, the cylinder testing structure comprises an inner cylinder and an outer cylinder, and an annular cavity between the inner cylinder and the outer cylinder is used for containing a tested textile; a heating element is arranged in the inner cylinder; the annular cavity comprises a temperature sensor array, and at least part of temperature sensors in the temperature sensor array are distributed on the outer side of the inner cylinder and the inner side of the outer cylinder. According to the scheme, the tested textile is placed by adopting the concentric cylinder testing structure which better conforms to the human body curved surface shape, so that the normal wearing state of the clothes can be better simulated, and the shape error between flat plate testing and real wearing is reduced; the thermal insulation performance parameters of the tested textile are determined by combining the temperature value and the heat flow detected in the test environment, the test result is more accurate, and the method has better actual reference value.