Integrated aerosol eliminating device

Abstract

The utility model discloses an integrated aerosol eliminating device which comprises an integrated box, a storage box is arranged on the outer side wall of the integrated box, a cleaning assembly is arranged in the storage box and used for cleaning gap settled dust in a target area, and a filtering assembly, an electrostatic adsorption assembly and a wind power negative pressure assembly are sequentially arranged in the integrated box. A plurality of air inlets are formed in the side, close to the filtering assembly, of the integration box, and the wind power negative pressure assembly is connected with an exhaust pipe extending out of the side wall of the integration box.

Description

Technical Field

[0001] This application relates to the field of air purification equipment technology, and in particular to an integrated aerosol elimination device. Background Technology

[0002] For aerosol spaces under complex operating conditions, such as confined spaces in nuclear power plants (e.g., maintenance and repair workshops), decontamination of nuclear technology utilization facilities / equipment, and nuclear accident emergency response capacity building, radioactive aerosols that have been generated or may be generated must be eliminated in a targeted manner within a limited time to meet the requirements of personnel accommodation, emergency response, functional restoration, and environmental protection.

[0003] Currently available aerosol elimination equipment on the market generally lacks the ability to eliminate aerosols in enclosed spaces, especially in instrument racks, control rooms, and low-voltage systems. These areas often have complex layouts, valuable instruments, and complex surfaces where dust is difficult to clean from crevices. There are also blind spots in the enclosures and equipment. Furthermore, the locations and spaces where valuable instruments are stored often do not allow the use of chemical cleaning agents or water for cleaning, nor are they suitable for non-professional disassembly. Because existing aerosol elimination equipment has limited functionality and is bulky and difficult to move, it is not suitable for targeted elimination in enclosed spaces, resulting in poor aerosol elimination effects. Utility Model Content

[0004] The main objective of this application is to provide an integrated aerosol elimination device, which aims to solve the technical problems of existing aerosol elimination devices having limited functions, large size, and difficulty in being moved, making them unsuitable for directional elimination in confined spaces.

[0005] To achieve the above objectives, this application provides an integrated aerosol elimination device, including an integrated box, a storage box on the outer wall of the integrated box, a cleaning component inside the storage box, the cleaning component being used to clean the crevices and settled dust in the target area, a filter component, an electrostatic adsorption component and a wind-powered negative pressure component being arranged sequentially inside the integrated box, a plurality of air inlets being provided on the side of the integrated box near the filter component, and an exhaust pipe extending out of the side wall of the integrated box being connected to the wind-powered negative pressure component.

[0006] Optionally, the cleaning component includes a telescopic rod, the telescopic end of which is detachably connected to a cleaning element, which is a flexible cleaning rod or an adhesive roller.

[0007] Optionally, a support base is provided at the bottom of the integrated box for engaging the telescopic rod, and a top cover is hinged or fastened to the top of the integrated box.

[0008] Optionally, the integrated box is equipped with a handle on the top and shock-absorbing pads at the four corners of the bottom.

[0009] Optionally, the filter assembly includes a pre-filter and a medium filter. The pre-filter is located near the air inlet, and the medium filter is located near the electrostatic adsorption assembly. The pre-filter is used to filter dust, suspended lint, and large-diameter aerosol particles in the air, while the medium filter is used to filter small and medium-diameter particles in the air.

[0010] Optionally, the wind-powered negative pressure assembly includes an air collecting hood connected to one side of the electrostatic adsorption assembly, a negative pressure fan connected to the other side of the air collecting hood, a main air pipe connected to the negative pressure fan, an aerosol monitor installed on the main air pipe, a three-way solenoid valve connected to the main air pipe, an exhaust pipe connected to one side of the three-way solenoid valve, a return pipe connected to the three-way solenoid valve, and the other end of the return pipe extending to the area between the air inlet and the filter assembly.

[0011] Optionally, the integrated box is equipped with a partition to divide the interior of the integrated box into an upper cavity and a lower cavity arranged vertically. The filter component, electrostatic adsorption component and wind-powered negative pressure component are all located in the lower cavity, and the return pipe is located in the upper cavity.

[0012] Optionally, the integrated box is equipped with a controller, and the negative pressure fan, aerosol monitor and three-way solenoid valve are all electrically connected to the controller. The outer wall of the integrated box is equipped with a touch screen that is electrically connected to the controller.

[0013] Optionally, an alarm electrically connected to the controller is also installed on the outer wall of the integrated box.

[0014] Optionally, the rated air volume of the negative pressure fan is Q0, and the expression for Q0 is:

[0015] Q0 = Q(1+K)

[0016] In the formula, Q is the processing air volume, and K is the additional coefficient for air leakage in the pipeline network, which is taken as 0.1 to 0.15;

[0017] The calculated air pressure of the negative pressure fan is Δp0, and the expression for Δp0 is:

[0018]

[0019] In the formula, Δp t The pressure loss is the sum of the total pressure loss of the pipeline network and the pressure loss of the electrostatic precipitator; K1 is the fan performance fluctuation coefficient; P0 and T0 are the corresponding pressure and temperature parameters in the fan performance table, respectively; P λ T and T represent the pressure and temperature parameters at the fan inlet under operating conditions, respectively.

[0020] The power of the negative pressure fan is N. e N e The expression is:

[0021]

[0022] In the formula, K2 is the motor standby coefficient, η1 is the total pressure efficiency of the negative pressure fan, and η2 is the mechanical transmission efficiency of the negative pressure fan.

[0023] The beneficial effects that this application can achieve are as follows:

[0024] When targeted elimination of aerosols and settled dust is required in a confined space, the cleaning components can be used to clean the crevices and settling dust in the target area. The cleaning components are then placed in the storage box to prevent loss. Next, the negative pressure wind turbine is activated to generate negative pressure. The air inlet is then directed towards the target area, drawing air into the integrated box. The air then passes through the filter and electrostatic adsorption components for purification, eliminating aerosol particles and other impurities. The purified air is then discharged from the exhaust pipe, thus achieving the combined elimination of aerosols and settled dust. Easily settled particles are removed using the cleaning components, while non-settling particles are filtered and adsorbed. Furthermore, due to the integrated structural design, the cleaning components are readily available, and the filter, electrostatic adsorption, and negative pressure wind turbine components are all integrated within the box. This allows for a lightweight and compact design, facilitating the movement of the entire device to target areas in confined spaces and improving the targeted elimination effect. Therefore, it can quickly and efficiently reduce the concentration of radioactive aerosols in confined spaces, providing a guarantee for rapid emergency response and resumption of work and production. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0026] Figure 1 This is a schematic diagram of the structure of an integrated aerosol elimination device according to an embodiment of this application;

[0027] Figure 2 This is a schematic diagram of the internal structure of an integrated aerosol elimination device according to an embodiment of this application;

[0028] Figure 3 This is a schematic diagram of the electrostatic adsorption component in an embodiment of this application.

[0029] Figure label:

[0030] 110-Integrated box, 111-Air inlet, 120-Storage box, 130-Cleaning assembly, 131-Telescopic rod, 132-Cleaning component, 140-Filter assembly, 141-Pre-filter, 142-Medium filter, 150-Electrostatic adsorption assembly, 160-Wind-powered negative pressure assembly, 161-Air collector hood, 162-Negative pressure fan, 163-Main air pipe, 170-Exhaust pipe, 180-Aerosol monitor, 190-Three-way solenoid valve, 210-Return pipe, 220-Support base, 230-Handle, 240-Shock-absorbing pad, 250-Block, 260-Controller, 270-Touch screen, 280-Alarm.

[0031] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0033] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0034] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0035] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0036] Example

[0037] Reference Figures 1-3 This embodiment provides an integrated aerosol elimination device, including an integrated box 110. A storage box 120 is provided on the outer wall of the integrated box 110. A cleaning component 130 is provided inside the storage box 120. The cleaning component 130 is used to clean the crevices and settled dust in the target area. A filter component 140, an electrostatic adsorption component 150 and a wind-powered negative pressure component 160 are arranged sequentially inside the integrated box 110. Several air inlets 111 are provided on the side of the integrated box 110 near the filter component 140. The wind-powered negative pressure component 160 is connected to an exhaust pipe 170 extending out of the side wall of the integrated box 110.

[0038] In this embodiment, when targeted removal of dust from a confined space is required, the cleaning component 130 is first used to clean the crevices and settled dust in the target area. Then, the cleaning component 130 is placed back into the storage box 120 to prevent loss. Next, the negative pressure wind component 160 is activated to generate negative pressure. At this time, the air inlet 111 is aligned with the target area, drawing air from the target area into the integrated box 110. The air then passes through the filter component 140 and the electrostatic adsorption component 150 for air purification, eliminating impurities such as aerosol particles. The purified air is then discharged from the exhaust pipe 170, thus achieving the removal of aerosols and settled dust. The device integrates the functions of cleaning and aerosol removal. It uses cleaning components to remove and peel off easily settled particles, and filters and adsorbs particles that are not suitable for settling. Furthermore, due to the integrated structural design of this embodiment, the cleaning component 130 can be used and removed at any time. The filter component 140, electrostatic adsorption component 150, and wind-powered negative pressure component 160 are all integrated in the integrated box 110. This allows the entire device to be lightweight, compact, and easy to move. The entire device can be used to target areas in confined spaces to improve the effect of targeted aerosol removal. Therefore, it can quickly and efficiently reduce the concentration of radioactive aerosols in confined spaces, providing a guarantee for rapid emergency response and resumption of work and production.

[0039] It should be noted that the electrostatic adsorption component 150 consists of a high-voltage electrostatic power supply, an electrostatic precipitator, and connecting lines. The electrostatic precipitator includes anode corona wires and dust collection plates electrically connected to the high-voltage electrostatic power supply. When polluted air enters the corona zone formed by multiple anode corona wires, the gas is ionized by high voltage, causing aerosol particles to become charged. These charged particles are collected as they flow through the electrostatic field, allowing for the targeted removal of plutonium and other radioactive isotopes from the air. Furthermore, a dual-zone positive corona discharge is employed to reduce the generation of ozone and nitrogen oxides.

[0040] As an optional implementation, the cleaning assembly 130 includes a telescopic rod 131, the telescopic end of which is detachably connected to a cleaning component 132, which is a flexible cleaning rod or an adhesive roller.

[0041] In this embodiment, the telescopic rod 131 can be an electric push rod, which facilitates the extension of the cleaning component 132 to the gaps in the target area. It is mainly used for cleaning and removing dust that has settled in the gaps. After cleaning, the cleaning component 132 can be disassembled and replaced. Here, fasteners such as snap-fit, screws, and pins can be used to achieve a detachable structure, so that a flexible cleaning stick or an adhesive roller can be selected as needed. The telescopic rod 131 is made of titanium alloy. The main component of the flexible cleaning stick is cleaning soft rubber, which has repeated adhesion, is flexible and not easy to break. The adhesive roller evenly wraps the cleaning mud around the roller shaft. Similar to the action of brushing a wall, it is used to remove dirt from relatively regular surfaces such as control screens. For relatively flat surfaces such as walls, floors, tables and chairs, after spraying the peelable film (self-spraying bottle), it is manually peeled off in sequence after half an hour. The self-spraying bottle can be stored in the storage box 120 for flexible use.

[0042] As an optional implementation, a support base 220 is provided at the bottom of the integrated box 110. The support base 220 is used to snap the telescopic rod 131. The support base 220 facilitates temporary fixation of the telescopic rod 131 and prevents the telescopic rod 131 from shaking when the integrated box 110 is moved. The top of the integrated box 110 is hinged or snapped with a top cover, which can be opened when needed.

[0043] As an optional implementation, the integrated box 110 is provided with a handle 230 on the top for easy carrying or hoisting, and shock-absorbing pads 240 are provided at the four corners of the bottom of the integrated box 110 to reduce vibration during operation.

[0044] As an optional implementation, the filter assembly 140 includes a pre-filter 141 and a medium filter 142. The pre-filter 141 is located near the air inlet 111, and the medium filter 142 is located near the electrostatic adsorption assembly 150. The pre-filter 141 is used to filter dust, suspended lint and large-diameter aerosol particles in the air, and the medium filter 142 is used to filter small and medium-diameter particles in the air.

[0045] In this embodiment, aerosols are eliminated by using physical methods and incremental filtration techniques of pre-filtration and filtration based on calculations. Environmentally friendly and pollution-free peelable membrane technology is used to collect settled ash, effectively eliminating complex aerosols that escape from nuclear power plants, reprocessing plants, and civilian nuclear technology facilities / equipment under normal and abnormal operating conditions.

[0046] It should be noted that the pre-filter 141 is mainly used to filter dust, suspended lint, and large-particle aerosols in the air. It consists of filter cloth and a flared nozzle, and its outer casing is designed with a non-metallic frame structure (to reduce metal waste). The filter cloth is made of G3 grade non-woven fabric and uses a slot fixing method. The flared nozzle can be rectangular or circular (selected flexibly according to the actual site conditions). The filter element shape can be customized, or the basic product size of mainstream products on the market can be selected. The intermediate filter 142 is used to filter small and medium-sized particles (0.5-2.5μm). The intermediate filter adopts a two-stage series configuration. The first half uses a medium-efficiency nuclear-grade filter produced by Henan Nuclear Cleaning Company or China Institute of Radiation Protection. The technical parameters are as follows: filtration efficiency: 45% (counting method, >0.5μm); initial resistance: ≤100Pa; rated air volume: 3400m³. 3 / h; The latter half uses a mainstream nuclear-grade high-efficiency filter with the following technical parameters: filtration efficiency: ≥99.99% (sodium flame method); initial resistance: ≤325Pa; rated air volume: 3400m³ / h. 3 / h.

[0047] As an optional implementation, the wind-powered negative pressure assembly 160 includes an air collecting hood 161 connected to one side of the electrostatic adsorption assembly 150. The other side of the air collecting hood 161 is folded up and connected to a negative pressure fan 162. The negative pressure fan 162 is connected to a main air pipe 163. An aerosol monitor 180 is installed on the main air pipe 163. A three-way solenoid valve 190 is connected to the main air pipe 163. An exhaust pipe 170 is connected to one side of the three-way solenoid valve 190. The three-way solenoid valve 190 is also connected to a return pipe 210. The other end of the return pipe 210 extends to the area between the air inlet 111 and the filter assembly 140.

[0048] In this embodiment, the negative pressure fan 162 generates negative pressure during operation, and polluted gas enters the integrated box 110 from the air inlet 111. Then, it passes through the pre-filter 141 to filter out dust, suspended lint, and large-diameter aerosol particles in the air, and then passes through the medium filter 142 to filter out small and medium-diameter particles (0.5-2.5μm) before entering the electrostatic dust collector. Here, the aerosol monitor 180 monitors the air online. If the air does not meet the standard, the three-way solenoid valve 190 connects only the return pipe 210, and the air continues to enter the next-level processing unit for further processing until the standard is met. Then, the three-way solenoid valve 190 connects only the exhaust pipe 170 to discharge the air into the environment. By adding a monitoring link, internal air circulation purification can be performed to ensure the purification effect.

[0049] It should be noted that the aerosol monitor 180 can be equipped with an α / β radioactivity monitor (a mainstream product on the market), with the following technical specifications: Detector: ZnS(Ag) + plastic scintillator; Background count: α≤0.1cps; β≤15cps; Measurement range: α: 0~10000cps; β: 0~50000cps; Alarm threshold: α: 100cps; β: 500cps.

[0050] As an optional implementation, the integrated box 110 is provided with a partition 250 to divide the interior of the integrated box 110 into an upper cavity and a lower cavity arranged vertically. The filter assembly 140, the electrostatic adsorption assembly 150 and the wind-powered negative pressure assembly 160 are all located in the lower cavity, and the return pipe 210 is located in the upper cavity.

[0051] In this embodiment, the upper cavity and the lower cavity can form two independent air ducts, thereby performing gas purification and gas recirculation treatment respectively. Alternatively, the arrangement of the recirculation pipe 210 in the upper cavity can be omitted. The recirculation pipe 210 is only connected to the bottom of one side of the partition 250 and communicates with the upper cavity. A recirculation port is opened on the top of the other side of the partition 250, so that the entire upper cavity forms a recirculation air duct.

[0052] As an optional implementation, the integrated box 110 is equipped with a controller 260, and the negative pressure fan 162, aerosol monitor 180 and three-way solenoid valve 190 are all electrically connected to the controller 260. The outer wall of the integrated box 110 is equipped with a touch screen 270 that is electrically connected to the controller 260.

[0053] In this embodiment, the controller 260 can interact and control the negative pressure fan 162, the aerosol monitor 180, and the three-way solenoid valve 190, enabling the components to operate automatically and collaboratively without human intervention. Information can be viewed or related operations performed via the touchscreen 270, meeting a wider range of application scenarios. The controller 260 can be an S7-200 PLC controller, and a power module can be configured within the integrated box 110 to meet the requirements for autonomous operation.

[0054] As an optional implementation, the outer wall of the integrated box 110 is also equipped with an alarm 280 electrically connected to the controller 260, which can sound an alarm when an abnormality in radioactivity is detected, so as to remind the staff to check in time.

[0055] It should be noted that a pressure sensor can also be installed inside the intermediate filter 142, and an alarm can be triggered by the alarm 280 when an abnormal pressure is detected.

[0056] As an optional implementation, the rated air volume of the negative pressure fan 162 is Q0, and the expression for Q0 is:

[0057] Q0 = Q(1+K)

[0058] In the formula, Q is the processing air volume (unit: m³ / s). 3 / h), K is the additional coefficient for air leakage in the pipeline network, which is taken as 0.1 to 0.15;

[0059] The calculated air pressure of negative pressure fan 162 is Δp0, and the expression for Δp0 is:

[0060]

[0061] In the formula, Δp t The total pressure loss of the pipeline network and the pressure loss of the electrostatic precipitator are the sum of these values ​​(in Pa). K1 is the fan performance fluctuation coefficient (generally taken as 0.1). P0 and T0 are the corresponding pressure and temperature parameters in the fan performance table, respectively. λ T and T represent the pressure and temperature parameters at the fan inlet under operating conditions, respectively.

[0062] The power of negative pressure fan 162 is N e N e The expression is:

[0063]

[0064] In the formula, K2 is the motor standby coefficient (when the power of the negative pressure fan 162 is 2 to 5KW, K2 is 1.2; when its power is greater than 5KW, K2 is 1.15), η1 is the total pressure efficiency of the negative pressure fan 162 (generally 0.5 to 0.7), and η2 is the mechanical transmission efficiency of the negative pressure fan 162 (1 for direct drive, 0.98 for coupling drive, and 0.95 for belt drive).

[0065] In this embodiment, based on the above-mentioned parameter design of the negative pressure fan 162, the working parameters of the fan can be designed and the model of the negative pressure fan 162 can be selected according to the size of the operating room, the airflow resistance of the device duct and the limitations of the working environment, so as to maximize the effective matching of the negative pressure fan 162 with the actual working environment.

[0066] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. An integrated aerosol elimination device, characterized in that, The device includes an integrated box, with a storage box on the outer wall of the integrated box. A cleaning component is installed inside the storage box. The cleaning component is used to clean the crevices and settled dust in the target area. A filter component, an electrostatic adsorption component, and a wind-powered negative pressure component are arranged sequentially inside the integrated box. Several air inlets are provided on the side of the integrated box near the filter component. The wind-powered negative pressure component is connected to an exhaust pipe that extends out of the side wall of the integrated box.

2. The integrated aerosol elimination device as described in claim 1, characterized in that, The cleaning assembly includes a telescopic rod, the telescopic end of which is detachably connected to a cleaning component, which is a flexible cleaning rod or an adhesive roller.

3. The integrated aerosol elimination device as described in claim 2, characterized in that, The bottom of the integrated box is provided with a support base, which is used to snap the telescopic rod. The top of the integrated box is hinged or fastened with a top cover.

4. An integrated aerosol elimination device as described in any one of claims 1-3, characterized in that, The integrated box is equipped with a handle on the top and shock-absorbing pads at the four corners of the bottom.

5. An integrated aerosol elimination device as described in claim 1, characterized in that, The filtration assembly includes a pre-filter and a medium-sized filter. The pre-filter is located near the air inlet, and the medium-sized filter is located near the electrostatic adsorption assembly. The pre-filter is used to filter dust, suspended lint, and large-diameter aerosol particles in the air, and the medium-sized filter is used to filter small- and medium-diameter particles in the air.

6. An integrated aerosol elimination device as described in claim 1, characterized in that, The wind-powered negative pressure assembly includes an air collecting hood connected to one side of the electrostatic adsorption assembly. The other side of the air collecting hood is folded down and connected to a negative pressure fan. The negative pressure fan is connected to a main air pipe. An aerosol monitor is installed on the main air pipe. A three-way solenoid valve is connected to the main air pipe. An exhaust pipe is connected to one side of the three-way solenoid valve. The three-way solenoid valve is also connected to a return pipe. The other end of the return pipe extends to the area between the air inlet and the filter assembly.

7. An integrated aerosol elimination device as described in claim 6, characterized in that, The integrated box is equipped with a partition to divide the interior of the integrated box into an upper cavity and a lower cavity arranged vertically. The filter component, the electrostatic adsorption component and the wind-powered negative pressure component are all located in the lower cavity, and the return pipe is located in the upper cavity.

8. An integrated aerosol elimination device as described in claim 6, characterized in that, The integrated box is equipped with a controller. The negative pressure fan, the aerosol monitor, and the three-way solenoid valve are all electrically connected to the controller. The outer wall of the integrated box is equipped with a touch screen that is electrically connected to the controller.

9. An integrated aerosol elimination device as described in claim 8, characterized in that, An alarm, electrically connected to the controller, is also installed on the outer wall of the integrated box.

10. An integrated aerosol elimination device as described in any one of claims 6-9, characterized in that, The rated air volume of the negative pressure fan is Q0, and the expression for Q0 is: Q0 = Q(1+K) In the formula, Q is the processing air volume, and K is the additional coefficient for air leakage in the pipeline network, which is taken as 0.1 to 0.15; The calculated air pressure of the negative pressure fan is Δp0, and the expression for Δp0 is: In the formula, Δp t The pressure loss is the sum of the total pressure loss of the pipeline network and the pressure loss of the electrostatic precipitator; K1 is the fan performance fluctuation coefficient; P0 and T0 are the corresponding pressure and temperature parameters in the fan performance table, respectively; P λ T and T represent the pressure and temperature parameters at the fan inlet under operating conditions, respectively. The power of the negative pressure fan is N. e N e The expression is: In the formula, K2 is the motor standby coefficient, η1 is the total pressure efficiency of the negative pressure fan, and η2 is the mechanical transmission efficiency of the negative pressure fan.

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