Layered composite carbon dioxide absorber and failure monitoring method thereof

Abstract

The invention belongs to the technical field of anesthesia equipment, and particularly relates to a layered composite carbon dioxide absorber and a failure monitoring method thereof. The layered isolation design is adopted, anesthetic gas preferentially passes through the lithium hydroxide adsorption layer, compared with a single soda lime layer, the lithium hydroxide layer is added, the carbon dioxide absorption capacity can be improved, the side reaction with anesthetic is reduced, and the overall service life of the absorber is remarkably prolonged.

Description

Technical Field

[0001] This invention belongs to the field of anesthesia equipment technology, specifically a layered composite carbon dioxide absorber and its failure monitoring method. Background Technology

[0002] During general anesthesia, spontaneous breathing ceases, requiring endotracheal intubation and machine-assisted breathing. Currently, semi-closed anesthesia machines are commonly used clinically, requiring soda lime to absorb carbon dioxide from the airway that cannot be expelled by the machine. Upon absorbing carbon dioxide, a chemical reaction occurs in the soda lime, generating significant heat and producing sodium carbonate and water. The water combines with the desiccant in the soda lime, preventing water accumulation in the tubing. Additionally, a pH indicator is added to the soda lime to allow doctors to monitor its deterioration. Deteriorated soda lime must be replaced promptly; failure to do so can lead to carbon dioxide buildup in the patient's body, causing "carbon dioxide anesthesia," which is life-threatening.

[0003] However, traditional soda lime containers have the following drawbacks:

[0004] When the anesthesia machine is not in use but ventilation continues, the soda lime (containing sodium / potassium hydroxide) loses moisture due to prolonged exposure to dry airflow. This dry, highly alkaline environment can cause a violent dehalogenation reaction with inhaled anesthetics (such as sevoflurane or desflurane), generating large amounts of CO. If this is not adequately replaced or checked before the first use after a period of continuous use, the patient may inhale high concentrations of CO, leading to carbon monoxide poisoning.

[0005] Sodium lime has a high risk of deliquescence and failure, requiring strict humidity control, and is poorly suited for complex environments such as field medical settings. Moisture absorption and clumping increase airflow resistance; the specific process is: hardening after moisture absorption → increased airflow resistance → blockage of anesthesia machine tubing (traditional dust rate > 3%). The heat generated during the regeneration reaction affects equipment temperature control, posing a risk of thermal runaway: the heat of reaction per unit mass is as high as 1400 kJ / kg, causing a significant temperature rise (> 15℃) in confined spaces; the specific process is: exothermic CaO hydration reaction → sudden local temperature rise → affecting the stability of anesthetic gases. Sodium lime alone has a high failure rate; the adsorption rate typically decreases significantly after 2-3 hours of use, and after 8 hours, the safety of surgery cannot be guaranteed. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and propose a layered composite carbon dioxide absorber. This invention employs a layered isolation design, allowing anesthetic gases to preferentially pass through the lithium hydroxide adsorption layer. Compared to a single soda lime layer, the addition of the lithium hydroxide layer improves carbon dioxide absorption capacity, reduces side reactions with anesthetics, and significantly extends the overall service life of the absorber.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A layered composite carbon dioxide absorber, the absorber comprising a top cover and a tank;

[0009] The top cover is provided on the opening of the tank body, and the top cover is provided with an air inlet and an air outlet; the air outlet and the air inlet are respectively connected to the interior of the tank body.

[0010] The inner wall of the tank is provided with raised spiral patterns. Lithium hydroxide isolation components and soda lime isolation components are stacked sequentially from top to bottom on the raised spiral patterns. After assembly, the lithium hydroxide isolation components and soda lime isolation components together form a gas guiding flow path.

[0011] The gas guiding flow path is the direction of gas flow within the tank; the gas starts from the inlet, passes sequentially through the lithium hydroxide isolation component and the soda lime isolation component, and then passes through the gap between the side walls of the lithium hydroxide isolation component and the soda lime isolation component and the tank body, and is discharged from the outlet.

[0012] The lithium hydroxide isolation component has a built-in lithium hydroxide particle adsorption layer, and the soda lime isolation component has a built-in soda lime particle adsorption layer.

[0013] The adsorption unit consists of a lithium hydroxide particle adsorption layer and a soda lime particle adsorption layer, wherein the lithium hydroxide particle adsorption layer accounts for 30% to 50% of the total volume of the adsorption unit, and the soda lime particle adsorption layer accounts for 50% to 70% of the total volume of the adsorption unit.

[0014] Preferably, there are three groups of soda lime isolation components and lithium hydroxide isolation components, each group including one soda lime isolation component and one lithium hydroxide isolation component, and the soda lime isolation components and lithium hydroxide isolation components are stacked alternately.

[0015] Preferably, the lithium hydroxide particle adsorption layer is made of medical woven mesh with a pore size of 0.3~0.5 mm filled with lithium hydroxide particles with a particle size of 1.0~3.0 mm; and 0.3%~0.8% of hydrophobic fumed silica is added to the lithium hydroxide particle adsorption layer.

[0016] Preferably, the soda lime particle adsorption layer is made of a medical woven mesh with a pore size of 0.3~0.5 mm filled with soda lime particles with a particle size of 2.0~4.0 mm, and the soda lime particle adsorption layer contains 0.5%~1.0% calcium stearate by mass of soda lime particles.

[0017] Preferably, the soda lime granules comprise the following components by mass percentage: 4%~20% sodium hydroxide, 60%~80% calcium oxide, 5%~10% magnesium silicate slow-release agent, and 0.5%~1% phenolphthalein indicator.

[0018] Preferably, both the soda lime isolation component and the lithium hydroxide isolation component are made of 316L medical stainless steel woven mesh with a pore size of 0.3~0.5 mm and a surface coating of a nano-silica film with a thickness of 50±5 μm.

[0019] Preferably, the absorber further includes a cooling module and a temperature sensor; the temperature sensor is disposed in the temperature sensor mounting hole of the upper cover and is used to monitor the temperature of the gas inside the tank.

[0020] The cooling module is located at the bottom of the tank and is used to cool the inside of the tank.

[0021] Preferably, the cooling module includes a thermoelectric cooler, a heat sink, and a fan, wherein the heat sink is attached to the thermoelectric cooler, and the fan is used to accelerate the airflow through the heat sink.

[0022] The present invention also provides a method for monitoring the failure of a stratified composite carbon dioxide absorber, the monitoring method comprising the following steps:

[0023] 1) The anesthesia system uses the aforementioned layered composite carbon dioxide absorber;

[0024] 2) Start monitoring and monitor three indicators in real time, including CO sensor reading, phenolphthalein color indicator and differential pressure sensor value;

[0025] 3) Determine whether the CO sensor reading is greater than 10 ppm and the duration is greater than 30 seconds. Also, determine whether the phenolphthalein turns from powder to white, whether the system running time is greater than 8 hours, and whether the pressure difference between the inlet and outlet is greater than 2.5 kPa.

[0026] If any judgment result is yes, a failure alarm is triggered, the anesthesia system will sound an audible and visual alarm, and the main unit will lock the gas output; after the failure alarm is triggered, the absorber is replaced, and the installation of the new absorber is confirmed; after the installation is confirmed, the timer and sensor are reset, the main unit is unlocked, and monitoring continues.

[0027] If all judgment results are negative, monitoring will continue.

[0028] In the above method, when the phenolphthalein color indicator in the adsorption layer changes color, the user can observe the color change through the transparent container, and then operate the anesthesia system to trigger a failure alarm.

[0029] In the above method, the readings of the CO sensor and the differential pressure sensor can be displayed on the screen of the anesthesia system. When the corresponding monitoring value is reached, a failure alarm can be triggered. The color indicators are observed by the user before the operation, so that failure can be detected before and after the operation.

[0030] Compared with the prior art, the technical advantages of the present invention are as follows:

[0031] 1) Elimination of toxic byproducts of anesthetics. Existing soda lime inevitably generates CO / fluoromethyl-2,2-difluoroether-1-propene ether upon contact with sevoflurane. This invention, through a layered isolation design, allows anesthetic gas to preferentially pass through the LiOH layer (reducing the reaction with sevoflurane), blocking direct contact between soda lime and the anesthetic, thus reducing the generation of byproducts.

[0032] 2) Balancing high efficiency and low cost. Using LiOH alone is too costly, while using soda lime alone is inefficient. This invention employs a 30%-50% lithium hydroxide pre-adsorption layer to absorb 80% of CO2 and a 50%-70% soda lime post-adsorption layer to treat residual gas, reducing the cost by 53% compared to the pure LiOH approach. Meanwhile, its efficiency is 1.7 times that of pure soda lime (58.2% vs 34.7%).

[0033] 3) Preventing the failure of the layered structure. Traditional mixing leads to interpenetration of particles, destroying the function. This invention reduces the dust rate to below 0.1% by employing triple physical isolation: a medical-grade stainless steel isolation mesh (pore size ≤ 0.5mm) blocks particle migration, a nano-SiO2 coating neutralizes the alkalinity of the interface, and a double-layer medical woven mesh moisture-proof packaging inhibits deliquescence and adhesion.

[0034] 4) Controlling thermal runaway in the mixed system. A single heat dissipation solution cannot handle the heat release from the mixture. This invention uses a graded temperature control strategy, with an embedded temperature sensor monitoring in real time (response time < 0.5s), and a micro fan activated at a 45℃ threshold for forced heat dissipation, keeping the temperature rise within a safe range of 8-10℃ (compared to 12-15℃ for a pure LiOH adsorption layer). Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the absorber structure of the present invention;

[0036] Figure 2 This is a schematic diagram of the gas guiding flow path of the absorber of the present invention;

[0037] Figure 3 This is a schematic diagram of the structure of the isolation component of the present invention;

[0038] Figure 4 This is a cross-sectional schematic diagram of the tank body of the present invention;

[0039] Figure 5 This is a schematic diagram of the monitoring process of the present invention;

[0040] Figure label:

[0041] 1. Top cover; 2. Tank body; 3. Cooling module; 4. Fan + radiator; 5. Sodium lime isolation component; 6. Lithium hydroxide isolation component; 7. Air outlet; 8. Air inlet; 9. Lithium hydroxide adsorption layer; 10. Sodium lime adsorption layer; 11. Temperature sensor; 12. Spiral texture; 13. Semiconductor cooling chip. Detailed Implementation

[0042] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0043] Example 1

[0044] like Figure 1-2 As shown, a layered composite carbon dioxide absorber includes an upper cover 1, a tank 2, and a cooling module.

[0045] The upper cover 1 is disposed on the opening of the tank body 2. The upper cover 1 is provided with an air inlet 8, an air outlet 7 and a temperature sensor mounting hole. The air outlet 7 and the air inlet 8 are respectively connected to the interior of the tank body 2. A temperature sensor 11 is disposed in the temperature sensor mounting hole to monitor the temperature of the gas inside the tank.

[0046] The cooling module 3 is located at the bottom of the tank 2; it is used to cool the inside of the tank.

[0047] The structural diagram of the tank 2 is shown below. Figure 4 As shown, there are raised spiral patterns 12 on the inner wall of the tank. When the lithium hydroxide isolation component 6 and the soda lime isolation component 5 are assembled into the tank 2, the spiral patterns 12 of the tank 2 and the side wall of the stainless steel filter screen in the isolation component form a flow channel for airflow.

[0048] like Figure 2 (Solid arrows indicate the direction of airflow in, and dashed arrows indicate the direction of airflow out.) As shown,

[0049] Specifically, the intake process (such as...) Figure 2 (As shown by the solid line in the diagram) The airflow enters through the air inlet 8 → lithium hydroxide adsorption layer 9 → lithium hydroxide isolation component (the isolation component has holes at the bottom and no holes on the sides; the structure is shown in the diagram). Figure 3 → Sodium lime adsorption layer 10 → Sodium lime isolation component → (Three-layer LiOH and sodium lime combination) to the bottom.

[0050] The process of exhaling (such as) Figure 2 As shown by the dashed line in the figure (which is spiral-shaped): the airflow at the bottom reaches the outlet port along the flow channel formed by the spiral pattern 12 of the tank body 2 and the side wall of the isolation component.

[0051] The lithium hydroxide isolation component 6 has a built-in lithium hydroxide particle adsorption layer 9, and the soda lime isolation component 5 has a built-in soda lime particle adsorption layer 10.

[0052] The lithium hydroxide particle adsorption layer 9 and the soda lime particle adsorption layer 10 constitute an adsorption unit, wherein the lithium hydroxide particle adsorption layer 9 accounts for 30% to 50% of the total volume of the adsorption unit, and the soda lime particle adsorption layer 10 accounts for 50% to 70% of the total volume of the adsorption unit.

[0053] In this embodiment, there are three sets of soda lime isolation components 5 and lithium hydroxide isolation components 6, which are stacked alternately. That is, the first layer is a lithium hydroxide isolation component, the second layer is a soda lime isolation component, the third layer is a lithium hydroxide isolation component, the fourth layer is a soda lime isolation component, the fifth layer is a lithium hydroxide isolation component, and the sixth layer is a soda lime isolation component.

[0054] The lithium hydroxide particle adsorption layer is made of medical woven mesh with a pore size of 0.3~0.5 mm, filled with lithium hydroxide particles with a particle size of 1.0~3.0 mm; 0.3%~0.8% of hydrophobic fumed silica is added to the lithium hydroxide particle adsorption layer.

[0055] The soda lime particle adsorption layer consists of a medical woven mesh with a pore size of 0.3-0.5 mm filled with soda lime particles with a particle size of 2.0-4.0 mm. 0.5%-1.0% (by weight of the soda lime particles) of calcium stearate is added to this soda lime particle adsorption layer. The medical woven mesh can be made of non-woven fabric, polypropylene, 304 stainless steel, or 316 stainless steel, etc.

[0056] The soda lime granules comprise the following components by mass percentage: 4%~20% sodium hydroxide, 60%~80% calcium oxide, 5%~10% magnesium silicate slow-release agent, and 0.5%~1% phenolphthalein indicator.

[0057] Both the soda lime isolation assembly and the lithium hydroxide isolation assembly are made of 316L medical-grade stainless steel woven mesh. The isolation assembly is a stepped cylinder with no openings on the side walls and openings at the bottom with a diameter of 0.3~0.5 mm. The surface is coated with a nano-silica film with a thickness of 50±5 μm. 316L medical-grade stainless steel woven mesh is commercially available.

[0058] The cooling module 3 includes a thermoelectric cooler 13, a heat sink, and a fan 4. The heat sink is attached to the thermoelectric cooler 13, and the fan is used to accelerate the airflow of the heat sink.

[0059] The tank body 2, the soda lime isolation component, and the lithium hydroxide isolation component of the present invention are designed with transparent windows and are made of transparent materials, such as glass or transparent resin.

[0060] The technical aspects of this invention are described in detail below:

[0061] I. Core Layered Structure Technical Solution:

[0062] 1. Layered adsorption unit:

[0063] (1) The lithium hydroxide isolation component with a built-in lithium hydroxide adsorption layer is used as the front-end high-efficiency layer:

[0064] 1) Composition: Lithium hydroxide (LiOH) granules:

[0065] 2) Content: 30%~50% of the total volume of the adsorption unit (volume percentage);

[0066] 3) Particle size range: 1.0~3.0 mm, which can optimize airflow distribution;

[0067] 4) LiOH adsorption layer additive: hydrophobic fumed silica (addition amount is 0.3%~0.8% of the mass of lithium hydroxide), used to reduce the deliquescence rate.

[0068] Experimental data shows that when the volume percentage of LiOH is less than 30%, the CO2 adsorption rate is less than 50%, resulting in a loss of high efficiency; when it is greater than 50%, the cost approaches that of the pure LiOH system, thus losing its economic viability. A balance between efficiency and cost can be achieved in the 30%–50% range (adsorption rate 58.2%, lithium hydroxide cost…). ).

[0069] (2) The soda lime isolation component with a built-in soda lime adsorption layer is used as the back-end buffer layer:

[0070] 1) Composition: Sodium lime, see Table 1 for details;

[0071] Table 1 Composition of Sodium Lime

[0072] Components mass percentage Function Sodium hydroxide 4%~20% <![CDATA[Main absorbent (Reaction formula: 2NaOH + CO2 → Na2CO3 + H2O)]]> Calcium oxide 60%~80% <![CDATA[Water-absorbing regenerant: (Strong water-absorbing reaction formula: CaO + H2O → Ca(OH)2 + heat; regenerant reaction formula: Na2CO3 + CaO → CaCO3 + 2NaOH)]]> Magnesium silicate sustained-release agent 5%~10% Suppressing the agglomeration rate Phenolphthalein indicator 0.5%~1% Failure indicator color change (pink → white) total 100% ——

[0073] 2) Content: 50%~70% of the total volume of the adsorption unit (volume percentage);

[0074] 3) Particle size range: 2.0~4.0 mm (to match the airflow resistance of the front-end layer);

[0075] 4) Sodium lime adsorption layer additive: calcium stearate (addition amount is 0.5%~1.0% of the total amount of sodium lime), to inhibit the alkaline polymerization caused by LiOH migration.

[0076] (3) The LiOH particles and soda lime particles are filled with a mesh made of medical woven mesh with a mesh size of 0.3~0.5 mm.

[0077] (4) Lithium hydroxide isolation components and soda lime isolation components:

[0078] Materials and structure: 316L medical-grade stainless steel woven mesh, such as... Figure 3 As shown.

[0079] Pore ​​size: 0.3~0.5 mm (“to prevent particle mixing”);

[0080] Surface coating of the isolation component: nano-silica film (thickness 50±5 μm) to neutralize the alkalinity of the interface (pH buffered to 7~9).

[0081] The isolation component has an opening at the bottom but no openings on the side walls, such as... Figure 3 As shown, after the gas enters through the inlet, it passes through the hole at the bottom of the isolation assembly, reaches the bottom of the last layer of the isolation assembly, and then flows along the annular channel formed by the wall of the isolation assembly and the protrusions of the tank to the outlet. The protrusions of the tank rise in a spiral pattern. Figure 4 , Figure 4 This is a schematic diagram of a cross-section along the central axis of the tank.

[0082] (5) Key parameter range setting data: According to the above technical solution, the key parameter range setting data in this invention are shown in Table 2 below:

[0083] Table 2. Setting of core parameters

[0084] parameter Range setting Experimental basis Boundary values LiOH layer volume percentage 30%~50% To achieve an adsorption efficiency of 58.2% 30% + 70% = 100% (lower limit) NaOH mass percentage 4%~20% Core functional areas NaOH 9% + CaO 80% + 11% additives = 100% Mesh size of isolation mesh 0.3~0.5 mm Requirements for preventing mixing <LiOH particle size (leak-proof) Temperature response threshold 45℃ Safety Limits <50℃ (medical anesthesia standard)

[0085] II. Security Enhancement Technology Solutions

[0086] 1. Dynamic temperature control system

[0087] 1) Temperature sensor: DS18B20 digital thermometer (accuracy ±0.4℃), embedded in tank 2;

[0088] 2) Heat dissipation actuator: semiconductor cooling chip, response threshold 45℃;

[0089] 3) Threshold setting: When the temperature rise is greater than 45℃, the side reaction is aggravated. Experiments show that when the temperature exceeds 50℃, the amount of fluoromethyl-2,2-difluoroether-1-propene ether generated increases by 300%. Therefore, the temperature threshold of 45℃ is when the heat dissipation actuator is turned on.

[0090] 4) Circuit design: The MCU compares the temperature signal in real time with a delay response of <0.3 seconds (to prevent heat buildup).

[0091] 2. Byproduct blocking design

[0092] 1) Gas flow channel optimization: The air inlet is located at the center of the LiOH adsorption layer and is ≥15 mm away from the isolation net (to ensure that the gas has priority contact with LiOH).

[0093] 2) Monitoring module: A threaded hole is made on the top cover, and an external sensor is connected through a pagoda connector and a flexible hose. It is not shown in the figure (generally, the sensor is connected externally through a hole).

[0094] 3) CO sensor (electrochemical type, range 0~500 ppm, accuracy ±1 ppm);

[0095] 4) Data output: RS485 interface connects to the anesthesia machine main unit;

[0096] The assembly and operation control process of the present invention is illustrated by the following preferred embodiments:

[0097] 1. The filling process for soda lime granules and LiOH granules is as follows:

[0098] 1) The mesh size of the woven mesh used for filling LiOH granules and soda lime is 0.4 mm;

[0099] 2) Fill the woven mesh with LiOH granules (2.0 mm in diameter) at a volume ratio of 35%;

[0100] 3) Fill the woven mesh with sodium lime (formula: 15% NaOH + 75% CaO + 8% magnesium silicate + 1% phenolphthalein + 1% calcium stearate) at a volume ratio of 65%;

[0101] 4) Place the filled LiOH woven mesh and soda lime woven mesh into the LiOH isolation component and soda lime isolation component respectively;

[0102] 5) This embodiment uses a combination of three-layer LiOH isolation components and three-layer soda lime isolation components.

[0103] 2. Operation Control:

[0104] 1) Gas flow direction: Inlet pipe → LiOH adsorption layer (adsorbs 80% CO2) → isolation component → soda lime adsorption layer → outlet pipe;

[0105] 2) Temperature control: When the temperature of the soda lime layer is ≥45℃, the thermoelectric cooler will start operating until the temperature drops below 40℃.

[0106] 3. Failure determination:

[0107] 1) The soda lime layer turns white (indicated by phenolphthalein);

[0108] 2) CO sensor reading > 10 ppm;

[0109] 3) Cumulative usage time > 8 hours.

[0110] like Figure 5 As shown, a method for monitoring the failure of a stratified composite carbon dioxide absorber includes the following steps:

[0111] 1) The anesthesia system uses the aforementioned layered composite carbon dioxide absorber;

[0112] 2) Start monitoring and monitor three indicators in real time, including CO sensor reading, phenolphthalein color indicator and differential pressure sensor value;

[0113] 3) Determine whether the CO sensor reading is greater than 10 ppm and the duration is greater than 30 seconds. Also, determine whether the phenolphthalein turns from powder to white, whether the system running time is greater than 8 hours, and whether the pressure difference between the inlet and outlet is greater than 2.5 kPa.

[0114] If any judgment result is yes, a failure alarm is triggered, the anesthesia system will sound an audible and visual alarm, and the main unit will lock the gas output; after the failure alarm is triggered, the absorber is replaced, and the installation of the new absorber is confirmed; after the installation is confirmed, the timer and sensor are reset, the main unit is unlocked, and monitoring continues.

[0115] If all judgment results are negative, monitoring will continue.

[0116] The detection logic of this invention is as follows: Figure 5 The software controller and circuit design both adopt the design of an anesthesia machine, which is a well-known technology in this field. The byproduct blocking design scheme of this invention adopts a scheme of three independent detections: color, gas, and time. If any one exceeds the standard, a failure ("OR" logic) is triggered. The judgment index and threshold settings are shown in the table below, and the judgment index is shown in Table 3 below:

[0117] Table 3

[0118] Judgment Item threshold Technical features Phenolphthalein color change Pink → White Tank 2 and the isolation assembly are designed with transparent viewing windows. CO concentration >10 ppm for 30 seconds CO sensor Runtime >8 hours Anesthesia machine built-in timer airflow resistance Pressure difference > 2.5 kPa Inlet and outlet differential pressure sensors

[0119] To prevent momentary interference, the CO sensor must collect a concentration that exceeds the standard for 30 seconds before it is considered to have failed and the failure logic is triggered.

[0120] This invention is the first to integrate multiple failure conditions, including "color visual judgment + continuous gas monitoring + time-based hard cutoff," overcoming the limitations of traditional single-based replacement criteria (such as reliance on color-changing indicators being susceptible to ambient light interference). The 30-second continuous CO concentration detection mechanism is specifically designed to address the risk of "patient CO poisoning," reflecting the core safety aspect of this invention.

[0121] The following table 4 compares the effectiveness of this invention in addressing the inherent problems of soda lime:

[0122] Table 4

[0123] Technical issues Existing solutions Invention Solution The effect of this invention Formation of toxic byproducts Sodium lime will inevitably produce CO / compound A Layered isolation blocks reaction pathways Byproducts were not detected. Cost and efficiency contradiction Pure LiOH is highly efficient but costs $120 / kg 40% LiOH mixed system $56 / kg Costs decreased by 53%, while efficiency remained at 85%. Thermal runaway of mixed system Temperature rise cumulatively to >15℃ 45℃ threshold forced heat dissipation Temperature rise suppressed to 8-10℃ Deliquescence and clumping Sodium lime hardens and LiOH deliquesces and becomes ineffective. Double-sealed packaging with desiccant Humidity sensitivity reduced by 70% Replacement cycle Maximum duration 8 hours, replace Sodium lime and lithium hydroxide composite layer Service life extended to 70 hours, replacement

[0124] The upper and lower limits of the process parameters (such as temperature, time, etc.) and the range values ​​of the present invention can all achieve this method, and examples are not listed here.

[0125] All aspects not described in detail in this invention can be covered using conventional technical knowledge in the field.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A layered composite carbon dioxide absorber, characterized in that, The absorber includes a top cover and a tank; The top cover is provided on the opening of the tank body, and the top cover is provided with an air inlet and an air outlet; the air outlet and the air inlet are respectively connected to the interior of the tank body. The inner wall of the tank is provided with raised spiral patterns. Lithium hydroxide isolation components and soda lime isolation components are stacked sequentially from top to bottom on the raised spiral patterns. After assembly, the lithium hydroxide isolation components and soda lime isolation components together form a gas guiding flow path. The gas guiding flow path is the direction of gas flow within the tank; the gas starts from the inlet, passes sequentially through the lithium hydroxide isolation component and the soda lime isolation component, and then passes through the gap between the side walls of the lithium hydroxide isolation component and the soda lime isolation component and the tank body, and is discharged from the outlet. The lithium hydroxide isolation component has a built-in lithium hydroxide particle adsorption layer, and the soda lime isolation component has a built-in soda lime particle adsorption layer. The adsorption unit consists of a lithium hydroxide particle adsorption layer and a soda lime particle adsorption layer, wherein the lithium hydroxide particle adsorption layer accounts for 30% to 50% of the total volume of the adsorption unit, and the soda lime particle adsorption layer accounts for 50% to 70% of the total volume of the adsorption unit.

2. The layered composite carbon dioxide absorber according to claim 1, characterized in that, There are three sets of soda lime isolation components and lithium hydroxide isolation components, which are stacked alternately.

3. The layered composite carbon dioxide absorber according to claim 1, characterized in that, The lithium hydroxide particle adsorption layer is made of medical woven mesh with a pore size of 0.3~0.5 mm, filled with lithium hydroxide particles with a particle size of 1.0~3.0 mm; 0.3%~0.8% of hydrophobic fumed silica by mass of lithium hydroxide particles is added to the lithium hydroxide particle adsorption layer.

4. The layered composite carbon dioxide absorber according to claim 1, characterized in that, The soda lime particle adsorption layer is made of a medical woven mesh with a pore size of 0.3~0.5 mm filled with soda lime particles with a particle size of 2.0~4.0 mm. 0.5%~1.0% of calcium stearate by mass of soda lime particles is added to the soda lime particle adsorption layer.

5. The layered composite carbon dioxide absorber according to claim 4, characterized in that, The soda lime granules comprise the following components by mass percentage: 4%~20% sodium hydroxide, 60%~80% calcium oxide, 5%~10% magnesium silicate slow-release agent, and 0.5%~1% phenolphthalein indicator.

6. The layered composite carbon dioxide absorber according to claim 1, characterized in that, The bottom openings of the soda lime isolation component and the lithium hydroxide isolation component have a diameter of 0.3~0.5 mm, and the surface is coated with a nano-silica film with a thickness of 50±5 μm.

7. The layered composite carbon dioxide absorber according to claim 1, characterized in that, The absorber also includes a cooling module and a temperature sensor; the temperature sensor is installed in the temperature sensor mounting hole on the top cover and is used to monitor the temperature of the gas inside the tank. The cooling module is located at the bottom of the tank and is used to cool the inside of the tank.

8. The layered composite carbon dioxide absorber according to claim 7, characterized in that, The cooling module includes a thermoelectric cooler, a heat sink, and a fan. The heat sink is attached to the thermoelectric cooler, and the fan is used to accelerate the airflow through the heat sink.

9. A method for monitoring the failure of a stratified composite carbon dioxide absorber, the monitoring method comprising the following steps: 1) The anesthesia system uses the layered composite carbon dioxide absorber as described in any one of claims 1-8; 2) Start monitoring and monitor three indicators in real time, including CO sensor reading, phenolphthalein color indicator and differential pressure sensor value; 3) Determine whether the CO sensor reading is greater than 10 ppm and the duration is greater than 30 seconds. Also, determine whether the phenolphthalein turns from powder to white, whether the system running time is greater than 8 hours, and whether the pressure difference between the inlet and outlet is greater than 2.5 kPa. If any judgment result is yes, a failure alarm is triggered, the anesthesia system will issue an audible and visual alarm, and the main unit will lock the gas output; After a failure alarm is triggered, replace the absorber and verify the installation of the new absorber; after installation verification, reset the timer and sensor, unlock the host, and continue monitoring; If all judgment results are negative, monitoring will continue.

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