WO2021037001A1 - Negative pressure screen and application thereof - Google Patents

Abstract

Disclosed in the present invention is a negative pressure screen. The negative pressure screen comprises a body weldment, an air inlet device, a purifying device, and negative pressure forming devices; the body weldment comprises a front body frame and a middle body frame, and the front body frame and the middle body frame are integrally connected; the air inlet device is positioned in the middle body frame and is of a plate-shaped frame structure; the purifying device and the negative pressure forming devices are all mounted inside the front body frame, and there are two negative pressure forming devices respectively mounted on the left and right sides of the purifying device. According to the negative pressure screen of the present invention, the structure is compact, consumables are saved, and the cost is reduced; by means of design of the air inlet device, all potentially risky contaminated gas exhaled by a patient can be sucked into the negative pressure screen to be purified and sterilized as much as possible.

Description

A negative pressure screen and its application Technical field

The invention relates to the technical field of air purification, in particular to a negative pressure screen and its application.

Background technique

The main ways of transmission of germs include air and droplet transmission.

Air transmission is mainly based on the air as the medium of transmission. The airflow of pathogenic microorganisms in the air causes the spread of diseases. It is one of the main ways to cause upper and lower respiratory tract infections. It can cause infections in many people and even lead to outbreaks of nosocomial infections. Tuberculosis, measles, and chickenpox are mainly spread through the air to cause the occurrence or outbreak of nosocomial infections.

Droplet transmission is mainly through coughing, sneezing or laughing loudly, especially droplets produced by patients with respiratory tract infectious diseases, because they contain respiratory mucosal secretions and a large number of pathogenic microorganisms, when susceptible persons are in close contact with them, they will Infection caused by inhalation. Such as influenza B virus, adenovirus, meningococcus, streptococcus, bacillus pertussis, group A hemolytic streptococcus, etc.

At present, the hospital mainly adopts the following measures for air and droplet transmission: (1) Pay attention to respiratory hygiene and cough etiquette; (2) Medical staff or visitors wear isolation gowns and protective clothing for personal protection; (3) Use "single person isolation" Room” and other methods.

The technology and products in the field of nosocomial infection prevention and control are still in a state to be improved. At present, there are not many products similar to this patent, and they are mainly positive pressure screens. Existing positive pressure screen products use cyclic purification, that is, only consider the air volume and the purification of the space. This kind of treatment will still cause cross-infection in the room. Although a very small number of negative pressure bed products adopt timely purification and elimination, the negative pressure area is designed at the location of the pollution source to absorb polluted air in time, but there are still problems such as mismatch with hospital equipment belts and other standard settings, noise, and inconvenience. .

Therefore, there is an urgent need to develop a small negative pressure screen that occupies a small space and matches the standard settings of hospital equipment belts.

Summary of the invention

Based on the above-mentioned shortcomings of the prior art, the present invention provides a negative pressure screen and its application in a clean integrated hospital bed. The negative pressure screen of the present invention has a compact structure, maximum absorption of pollutant gas, low noise, sufficient elimination, and balanced airflow, and can be used in the field of hospital sense prevention and control, especially for purifying integrated hospital beds.

The technical scheme of the present invention to solve the technical problem is as follows:

A negative pressure screen of the present invention includes a main body welding part, an air inlet device, a purification device, and a negative pressure forming device; the main body welding part includes a main body front frame and a main body middle frame, and the main body front frame and the main body middle frame are integrally connected; The air device is located in the middle frame of the main body, and the air inlet device is a plate-shaped frame structure; the purification device and the negative pressure forming device are installed inside the front frame of the main body, and there are two negative pressure forming devices, which are respectively installed on the left and right sides of the purification device .

Preferably, the air intake device includes a ventilation hole plate, a ventilation duct and an air duct cover plate; the ventilation hole plate, the ventilation duct and the air duct cover plate are tightly connected from the front to the back and are installed in the main frame.

Further, the middle position of the vent plate is provided with a central air inlet, and the edge of the vent plate is provided with side air inlets; the ventilation duct and the vent plate are sealed and covered to form an open half-frame pipe; the side air inlets are located inside the ventilation duct , The middle air inlet is located outside the ventilation duct; the inner side wall of the ventilation duct is enclosed in a hollow funnel shape, and the opening of the funnel is downward; the air outlet of the ventilation duct is provided with an air duct baffle.

Further, the ventilation duct has two air outlets, and the areas of the air outlets are equal.

Further, the ratio of the area of the opening of the funnel to the area of the air outlet is 3:1.

Further, the inner side wall is composed of a double-layer perforated wall surface, and a sound insulation material is placed in the middle of the double-layer perforated wall surface.

Preferably, the purification device is provided with a primary effect filter, an electrostatic device and an ozone decomposition network in sequence from top to bottom, and a flow-sharing plate is also installed at the bottom of the purification device.

Further, the current-sharing plate is a strip-shaped plate with a fold-line cross-section.

The second object of the present invention is the application of the aforementioned negative pressure screen in the field of hospital sense prevention and control.

The third objective of the present invention is based on the first and second objectives, invented a clean integrated hospital bed, which includes a bed body and the aforementioned negative pressure screen, and the head end of the bed body is placed in front of the main body of the negative pressure screen. Frame.

working principle:

When the negative pressure screen of the present invention is in operation, under the action of the negative pressure forming device, the air exhaled by the potentially risky patient is sucked into the negative pressure screen through the air inlet device, and enters the purification device through the air outlet of the air inlet device ; Then in the purification device, the gas passes through the multiple filters of the purification device, and is divided by the flow plate to the fans in the negative pressure forming device on the left and right sides; then the gas passes through the high-efficiency filter under the action of the fan, and finally from the main body Clean air is blown out from both sides of the front frame.

Beneficial effects:

(1)Compact overall structure:

The negative pressure screen of the present invention mainly includes an air inlet device, a purifying device and a negative pressure forming device. Through the main body welding part of the present invention, the placement position, mutual connection relationship and overall structure of the above three devices are more compact.

a. Reduce the height of the negative pressure screen to match the use of hospital equipment belts;

b. The negative pressure screen of the present invention is a plate-shaped frame structure, and the thickness is reduced, not only the appearance is more beautiful, but also the occupied space is reduced;

c. The negative pressure screen of the present invention has a compact structure, saves consumables and reduces costs.

(2) Prevent the spread of polluted air:

a. The ventilation hole plate in the air intake device of the present invention is provided with a middle air inlet and a side air inlet, which increases the inhalation area, so as to be able to inhale all the potentially risky contaminated gas exhaled by the patient into the negative body as much as possible. Purify and kill in the press screen;

b. Two auxiliary air ducts are formed by the ventilation ducts, and the main air duct is formed by the close covering of the ventilation orifice plate, the ventilation duct and the air duct cover plate. This kind of combined use of the main air duct and the auxiliary air duct can be Better prevent the spread of polluted air: most of the polluted air exhaled by the patient is sucked away through the main air duct, while the remaining polluted air that is not sucked away is sucked away through the auxiliary air duct;

c. The ratio of the air outlet area of the auxiliary air duct and the main air duct is 1:3; and the main air duct is in the shape of a funnel, and the auxiliary air duct air outlet is provided with air duct baffles to make the air outlet area smaller; the role of the negative pressure forming device When the air flow is the same, the narrower the air duct, the greater the wind speed, and the lower the pressure. In the air inlet device of the present invention, the main air duct is in the shape of a funnel. This setting of the duct outlet position can make the pressure at the outlet of the duct smaller, thereby increasing the pressure difference between the outside air and the main duct, and ultimately achieve the purpose of improving the suction effect of the main duct; for the outlet of the auxiliary duct , The air duct baffle is set to reduce the area of the air outlet of the auxiliary air duct, thereby reducing the pressure of the auxiliary air duct outlet, thereby increasing the pressure difference between the outside air and the auxiliary air duct, and improving the suction effect of the auxiliary air duct .

(3) Low noise:

a. The inner side wall of the ventilation duct of the present invention is composed of a double-layer orifice wall surface, which can gradually reduce the pressure on the wall surface from high to low, and release the pressure on the wall smoothly, so that the flow rate of the fluid on the surface wall is slowed down and noise is reduced;

b. Silencing materials are installed inside the wall of the double-layer orifice plate, which can significantly absorb sound;

c. The sound-absorbing material is installed inside the air intake device. When the negative pressure screen of the present invention is used, the human head is close to the negative pressure screen. Therefore, the noise of the patient's head position can be significantly reduced and the patient's comfort can be improved.

(4) Improve the killing effect:

Since the air equalization plate is installed at the bottom of the purification device, the air equalization plate has the effect of improving the killing efficiency, and the resistance when the gas flows through the air equalization plate is large, thereby reducing the flow velocity and making the air flow rate flowing through the purification device more uniform , Which can make the air contact with the filter screen more fully, and optimize the purification effect; the flow-sharing plate has a simple structure, easy processing, and low cost, and can thoroughly eliminate and purify polluted gases in a variety of ways.

(5) Air flow balance:

a. The negative pressure forming device of the present invention is arranged on both sides of the purification device, so that both the left and right sides of the main air duct and the auxiliary air duct produce uniform suction;

b. The areas of the auxiliary air ducts on the left and right sides of the air inlet device are equal. When the power of the fans on the left and right sides are equal, the negative pressure values of the auxiliary air ducts on the left and right sides are almost equal, which can stabilize the airflow;

c. There is a flow-sharing plate at the bottom of the purification device, which allows the gas from the purification device to evenly enter the negative pressure forming device on both sides to avoid turbulence in the internal air flow of the instrument;

d. Inside the negative pressure forming device, a wind deflector and a wind deflector ring are arranged at the rear of the fan. The wind deflector can guide the wind direction of the fan, and it can also make the air flow in a fixed direction.

(6) Reduce the sense of oppression:

The traditional isolation hospital bed adopts a cover structure, which will bring pressure to the patient, while the plate-shaped negative pressure screen of the present invention will not have any cover on the head when the patient is lying on the bed. The patient brings a sense of pressure, thereby enhancing the comfort of the patient.

Description of the drawings

Figure 1 is a schematic diagram of the structure of the negative pressure screen;

Figure 2 is a schematic diagram of the structure of the main body welded part in the negative pressure screen;

Figure 3 is a schematic diagram of the rear view of the disassembly of the air intake device

Figure 4 is a schematic side view of the inner side of the air intake device;

Figure 5 is a schematic cross-sectional structure diagram of the purification device;

Figure 6 is a schematic cross-sectional structure diagram of a negative pressure forming device;

Figure 7 is a schematic diagram of the structure of a clean integrated hospital bed;

Figure 8-1 is the front view of the air inlet device when the negative pressure screen does not distinguish between the main air duct and the auxiliary air duct;

Figure 8-2 is the bottom view of the air inlet device when the negative pressure screen does not distinguish between the main air duct and the auxiliary air duct;

Figure 8-3 is the front view of the air inlet area of the auxiliary air duct on the left: the hollow opening area of the main air duct: the area of the air outlet of the auxiliary air duct on the right = 1:2:1;

Figure 8-4 is a bottom view of the air inlet area of the auxiliary air duct on the left: the hollow opening area of the main air duct: the air outlet area of the auxiliary air duct on the right = 1:2:1;

Figure 8-5 is the front view of the air inlet area of the left auxiliary air duct: the hollow opening area of the main air duct: the air inlet area of the right auxiliary air duct = 1:3:1;

Figure 8-6 is the bottom view of the air inlet area of the left auxiliary air duct: the hollow opening area of the main air duct: the air inlet area of the right auxiliary air duct = 1:3:1;

Figure 9-1 is the front view of the negative pressure screen of the unilateral fan;

Figure 9-2 is the front view of the negative pressure screen of the double-sided fan;

Figure 10-1 is the left side view of the purification integrated hospital bed;

Fig. 10-2 is a top view of a clean integrated hospital bed.

1. Main body welded parts, 11. Front frame of main body, 12, Middle frame of main body; 15. High-efficiency filter;

2. Air inlet device, 21, ventilation hole plate, 22, ventilation duct, 23, air duct cover, 211, middle air inlet, 212, side air inlet, 221, inner side wall, 222, air duct baffle, 223 , Hollow opening, 224, air outlet, 2211, 2212, double-layer orifice wall;

3. Purification device, 31, primary effect filter, 32, electrostatic device, 33, ozone decomposition network;

4. Negative pressure forming device, 41, fan fixing bracket, 42, shock-proof rubber pad, 43, fan;

5. Bed body;

6. Flow sharing plate;

7. Air outlet of negative pressure screen.

detailed description

In order to more clearly describe the technical solutions in the embodiments of the present invention or the prior art, the technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present invention; obviously, the described The embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "rear", etc. are based on the drawings shown The orientation or positional relationship is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the pointed device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention.

For the preferred embodiments of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications are also regarded as the present invention. protected range.

Overall structure of negative pressure screen:

Fig. 1 is a schematic structural diagram of a negative pressure screen according to this embodiment; Fig. 2 is a schematic structural diagram of a main body welded part in the negative pressure screen.

It can be seen from Figures 1 and 2 that the negative pressure screen includes a main body welding part 1, an air inlet device 2, a purification device 3 and a negative pressure forming device 4; the main body welding part 1 includes a main body front frame 11 and a main body middle frame 12, the main body The front frame 11 and the main body middle frame 12 are integrally connected; the air inlet device 2 is located in the main body middle frame 12, and the air inlet device 2 has a plate-like frame structure; the purification device 3 and the negative pressure forming device 4 are both installed inside the main body front frame 11, In addition, there are two negative pressure forming devices 4, which are installed on the left and right sides of the purification device 3, respectively. Under the connection of the main body welded part 1, the air inlet device 2, the purification device 3 and the negative pressure forming device 4 form an air path from the air inlet device 2 → the purification device 3 → the negative pressure forming device 4.

The negative pressure screen of the present invention uses the main body welded part 1 to make the placement position, mutual connection relationship and overall structure of the air inlet device 2, the purification device 3 and the negative pressure forming device 4 more compact.

Air inlet device:

Fig. 3 is a schematic rear view of the disassembly of the air inlet device; Fig. 4 is a schematic side view of the inner side of the air inlet device. It can be seen from Figures 3 and 4 that the air inlet device 2 includes a vent plate 21, a vent duct 22 and an air duct cover 23; the vent plate 21, a vent duct 22 and an air duct cover 23 are closely connected from front to back, and are installed in The main body is inside the frame 11.

A middle air inlet 211 is provided at the middle of the vent plate 21, and side air inlets 212 are provided at the edge of the vent plate 21. The ventilation duct 22 and the ventilation hole plate 21 are sealed and covered to form an open half-frame duct; the side air inlet 212 is located inside the ventilation duct 22, and the middle air inlet 211 is located outside the ventilation duct 22. The inner side wall 221 of the ventilation duct 22 is enclosed in a hollow funnel shape, and the hollow opening 223 is downward to form a main air duct opening; the air outlet 224 of the ventilation duct 22 is provided with an air duct baffle 222. The ventilation duct 22 has two air outlets 224 to form auxiliary air duct openings, and the areas of the air outlets 224 are equal. The ratio of the area of the hollow opening 223 to the area of the air outlet 224 is 3:1. The inner side wall 221 is composed of double-layer orifice wall surfaces 2211 and 2212, and a sound insulation material is placed between the double-layer orifice wall surfaces 2211 and 2212.

Purification device:

Figure 5 is a schematic diagram of the cross-sectional structure of the purification device; it can be seen from Figure 5 that the purification device 3 is provided with a primary filter 31, an electrostatic device 32 and an ozone decomposition network 33 from top to bottom. The bottom of the purification device 3 is equipped with a flow sharing plate 6; The flow plate 6 is a strip-shaped plate with a broken line cross-section. As shown in Fig. 2, a high-efficiency filter 15 is also provided behind the air outlet 7 of the negative pressure screen to ensure that the exhausted gas is clean gas.

Negative pressure forming device:

Fig. 6 is a schematic cross-sectional structure diagram of the negative pressure forming device; it can be seen from Fig. 6 that the negative pressure forming device 4 includes a fan fixing bracket 41, a shock-proof rubber pad 42 and a fan 43; the fan fixing bracket 41 is sequentially installed with a shock-proof rubber pad 42 and a fan 43 , The negative pressure forming device 4 is fixed to the left and right sides of the purification device 3 through the fan fixing bracket 41.

Purification integrated hospital bed:

Fig. 7 is a schematic diagram of the structure of a clean integrated hospital bed. The hospital bed includes a bed body 5 and the negative pressure screen of the present invention, and one end of the bed body 5 is placed on the main body front frame 11 of the negative pressure screen.

The fan used in the present invention is a backward-inclined centrifugal fan, which is characterized by a small footprint and can meet the requirements of the present invention for a small footprint.

The effect of the negative pressure screen of the present invention:

1. The negative pressure screen of the present invention has a compact structure.

The length of the negative pressure screen of the present invention: 1232mm, width: 365mm, height: 1150mm, and the standard height of the hospital equipment belt is 1200mm from the bottom to the ground. Therefore, the height of the negative pressure screen of the present invention matches the use of hospital equipment belts. At the same time, because the negative pressure screen has a plate-like frame structure, the thickness is reduced, which not only has a more beautiful appearance, but also reduces the space occupied; saves consumables ,reduce costs.

2. The air intake device of the present invention can maximize the prevention of the diffusion of polluted air.

As described above, the ventilation hole plate 21 in the air intake device 2 is provided with a central air inlet 211 and a side air inlet 212 to increase the inhalation area, so as to maximize the potential risk of contaminated gas exhaled by the patient. It is sucked into the negative pressure screen for purification and disinfection; two auxiliary air ducts are formed through the ventilation duct 22, and the main air duct is formed by the tight closure of the vent plate 21, the ventilation duct 22 and the duct cover 23. This The combined use of the main air duct and the auxiliary air duct can better prevent the spread of polluted air: most of the polluted air exhaled by the patient is sucked away through the main air duct, while the remaining contaminated air that is not sucked away passes through the surrounding auxiliary air ducts. Was sucked away.

The auxiliary air duct air outlet 224 is provided with an air duct baffle 222 to make the air outlet area smaller; under the action of the negative pressure forming device 4, that is, when the pressure is constant, the smaller the air outlet area, the greater the pressure that can be generated Larger, the greater the pressure at the suction port, so that the suction effect of the air duct can be greatly improved without changing the power of the negative pressure forming device. In the present invention, the ratio of the area of the main air duct tuyere to the area of the auxiliary air duct tuyere is preferably 3:1.

Inhalation effect test of different air ducts:

Detection group 1: Figure 8-1 is the schematic diagram of the instrument wind speed detection points when the negative pressure screen does not distinguish between the main air duct and the auxiliary air duct. The detection points are respectively 1c to 12c, and Figure 8-2 shows the negative pressure screen regardless of the main air duct. Bottom view of the air duct with auxiliary air duct.

Two groups of detection: Figure 8-3 is a schematic diagram of the instrument wind speed detection points when the negative pressure screen is divided into the main air duct and the auxiliary air duct. The detection points are 1d-12d respectively. The air outlet area of the auxiliary air duct on the left side of the air inlet device of the equipment : Hollow opening area of the main air duct: Area of the air outlet of the auxiliary air duct on the right = 1:2:1, as shown in Figure 8-4.

3 groups of detection: Figure 8-5 is a schematic diagram of the instrument wind speed detection points when the negative pressure screen is divided into the main air duct and the auxiliary air duct. The detection points are respectively 1e-12e. The left auxiliary air duct of the air inlet device of this equipment is auxiliary. Air outlet area of the air duct: Hollow opening area of the main air duct: Area of the air outlet of the auxiliary air duct on the right = 1:3:1, as shown in Figure 8-6.

When the fan power is equal, the wind speed at the wind speed detection point is detected respectively, and the results are shown in Table 1.

Table 1 Wind speed test data

According to GB/T 18801-2015, after experimental testing, when the wind speed is close to 2m/s, the isolation effect can meet the standard requirements.

Therefore, in order to meet the standard requirements of the present invention, the wind speed of the main air duct is close to 2m/s. Without increasing the power of the fan, the setting of the baffle can significantly increase the wind speed of the main air duct tuyere. When the hollow opening of the air duct and the outlet area of the auxiliary air duct are 3:1, the effect of increasing the wind speed of the main air duct is the best.

As the main air duct tuyere is the main suction position, most of the polluted air has been sucked away. Therefore, for the auxiliary air duct, the wind speed is only required to be close to 0.5m/s to meet the requirements.

3. The way in which the ventilating duct of the present invention is installed with sound-absorbing materials reduces the noise of the equipment of the present invention.

The inner side wall of the ventilation duct of the present invention is composed of a double-layer orifice wall surface, which can gradually reduce the pressure on the wall surface from high to low, and release the pressure on the wall smoothly, so that the flow velocity of the fluid on the surface wall is slowed down, and the noise is reduced; The sound-absorbing material is installed inside the orifice wall, which can significantly absorb sound; the sound-absorbing material is installed inside the air intake device. When the negative pressure screen of the present invention is used, the human head is closer to the negative pressure screen, so the patient's head can be significantly reduced The noise at the central location improves patient comfort.

As shown in Figures 10-1 to 10-2, the present invention compares the noise reduction device installed at the ventilation hole and the noise reduction device installed at the air outlet. The specific detection position is 150mm from the head of the bed, and the distance from the negative pressure The position of the screen 180mm is detected. The test results are shown in Table 2.

Table 2 Noise test data of purification integrated isolation hospital bed

The test in Table 2 proves that the noise reduction device installed at the vent can effectively reduce the noise, and the noise reduction device installed at the air outlet does not have a significant noise reduction effect.

3. The current-sharing plate can improve the killing efficiency of the purification device of the present invention

When the gas flows through the flow-sharing plate, the resistance is large, thereby reducing the flow rate, making the flow rate of the air flowing through the purification device more uniform, enabling the air to contact the filter screen more fully, and optimizing the purification effect. The flow-sharing plate has a simple structure, easy processing, and low cost. The specific test results are shown in the following test results.

3.1. Detection of PM2.5 purification efficiency of particulate matter

Perform PM2.5 purification efficiency testing according to GB/T18801-2015.

3.1.1. Detection object

Cigarette smoke (≤2.5μm).

3.1.2. Test conditions

Ambient temperature: (20～25℃).

Environmental humidity: (50～70)%RH.

3.1.3. Test equipment

Test cabin (30m ³ ), dust tester (TSI 8530).

3.1.4. Machine running status

During the test, "high-end" and "high-pressure" are turned on.

3.1.5. Test steps

(1) Put the sample machine to be tested into the test chamber and turn on the power, check that it is running normally, and then turn off the sample machine.

(2) Open the background density and environmental temperature and humidity control system, controlling the background concentration of particles above 0.3μm concentration of less than 1X10 ⁴ th / L, temperature and humidity test reaches a predetermined state.

(3) Ignite the test standard cigarette and place it in the generator. When the initial concentration is controlled within the range of (5.0±1.0) mg/m ³ , stop the cigarette smoke. The mixing ceiling fan continued to stir for 2 minutes to evenly mix the PM2.5 concentration in the test chamber.

(4) After turning off the mixing fan for 3 minutes, measure the concentration of PM2.5.

(5) Turn on the sample machine to be tested and continue to purify for 60 minutes, and then measure the PM2.5 concentration in the cabin.

(6) Follow steps (1)-(5) without opening the prototype, and test the natural attenuation.

3.1.6. Calculation formula

Natural decay rate

(C0' is the initial concentration of the control group, Ct' is the final concentration of the control group);

Purification efficiency

(C0 is the initial point concentration of the test group, Ct is the end point concentration of the test).

According to the above-mentioned method for detecting the PM2.5 purification efficiency of particulate matter, the PM2.5 purification efficiency of the negative pressure screen without the flow sharing plate and the negative pressure screen with the flow sharing plate are respectively detected, and the results are shown in Table 3.

Table 3 PM2.5 purification efficiency

From the above data in Table 3, it can be seen that the PM2.5 purification efficiency is increased from 99.01% to 99.95% after the flow sharing plate is installed, which significantly improves the purification efficiency.

3.2. Detection of sterilization rate test

3.2.1. Detection method

GB 21551.3-2010 Appendix A for special requirements for antibacterial, sterilizing, and purifying air purifiers for household and similar electrical appliances.

3.2.2. Test strains

Staphylococcus albicans 8032.

3.2.3. Test conditions

1) Ambient temperature: (20～25)℃.

2) Environmental humidity: (50～70)%RH.

3.2.4. Test equipment

Test chamber (30m ³ ), six-stage mesh air impact sampler (FA-1), microbial aerosol generator, nutrient agar medium.

3.2.5. Machine running status

During the test, "high-end" and "high-pressure" are turned on.

3.2.6. Calculation formula

Natural death rate

(V0 is the amount of bacteria in the air before the test in the control group, and Vt is the amount of bacteria in the air after the test in the control group);

Sterilization rate

(V1 is the amount of bacteria in the air before the test in the experimental group, and V2 is the amount of bacteria in the air after the test in the experimental group).

According to the above detection method, the sterilization rate of the instrument is tested when the flow sharing plate is installed and the flow sharing plate is not installed on the instrument of the present invention, and the results are shown in Table 4.

Table 4 Test data of sterilization rate

From the data in Table 4, it can be seen that the sterilization rate of the negative pressure screen increased from 99.21% to 99.92% after the flow sharing plate was installed, which significantly improved the sterilization rate of the negative pressure screen.

For the negative pressure screen, it is very difficult to increase the sterilization rate from 99.21% to 99.92%. The present invention installs a flow plate at the bottom of the purification device to slow down the wind speed flowing through the purification device, so that the bacteria-carrying gas can fully contact the purification device. Thereby improving the sterilization efficiency of the negative pressure screen, and achieved unexpected results.

4. The purification device of the present invention can maximize the barrier efficiency and elimination efficiency of microorganisms and particulates.

The negative pressure screen of the present invention has a unique design for the air inlet device, which can achieve that all the contaminated air exhaled by the patient is sucked into the negative pressure screen. At the same time, the purification device of the present invention is equipped with multi-stage filtration to prevent pollution in a variety of ways. The gas is thoroughly sterilized and purified. A flow equalizing plate is installed at the lower part of the purification device. The resistance when the gas flows through the flow equalizing plate is large, thereby reducing the flow rate, making the air flow rate flowing through the purification device more uniform, and making the air contact filter. The net is more sufficient, so that the polluted air is exhausted after being fully disinfected and purified inside the purification device to ensure the cleanliness of the exhaust gas, so as to achieve a good barrier effect.

The flow-sharing plate has simple structure, easy processing and low cost. According to the testing standard GB/T18801-2015, compare the purification effects of the following negative pressure screens without and with the flow sharing plate installed:

4.1. Microbial barrier efficiency test data

4.1.1. Test strain

Mycobacterium bovis (BCG).

4.1.2. Test conditions

1) Ambient temperature: (20～25℃).

2) Environmental humidity: (50～70)%RH.

4.1.3. Test equipment

Test cabin (30m ³ ), six-stage mesh air impingement sampler (FA-1), microbial aerosol generator, 7H11 culture medium.

4.1.4. Machine running status

During the test, "high-end" and "high-pressure" are turned on.

4.1.5. Test steps

1) Place the prototype to be inspected in a 30m ³ test chamber, adjust the prototype to the working state of the test, verify that it runs normally, and then close the prototype.

2) Set up a microbial aerosol generator in the middle of the sample machine head 20cm to simulate the breathing position of the patient, and set a sampling point 30cm above the microbial aerosol generator as the initial point of microbial concentration, which is recorded as V0; in addition, in the sample machine The microbial concentration sampling points are set at a distance of 0.5m around (front, right, left, and rear) and 1.5m high, which are recorded as Vi (1, 2, 3...).

3) Turn on the negative pressure screen, purify the air in the cabin, and start the temperature and humidity control device at the same time, so that the humidity in the cabin reaches the specified state of the test.

4) Turn on the negative pressure screen purification function. After 10 minutes of stable operation, start the microbial aerosol generator, continue to generate 20 minutes, sampling at each point at the same time, record data every 5 minutes, stop sampling after 20 minutes of continuous testing, and the test is over.

5) Set up a control group, repeat 3) ~ 4), but do not turn on the prototype purification function.

4.1.6. Calculation formula

Natural barrier efficiency

(V0' is the average value of the initial point concentration of the control group, and Vi' is the average value of the concentration of each point in the four weeks of the control group).

Barrier efficiency

(V0 is the average value of the initial point concentration of the test group, and Vi is the average value of the concentration of each point around the test group).

Table 5 Test data of microbial barrier efficiency

From the data in Table 5, it can be seen that the microbial barrier efficiency of the purification integrated isolation hospital bed of the present invention reaches more than 98.77%, has a very good barrier effect, prevents the spread of pathogenic bacteria exhaled by the patient on the hospital bed, and can kill the pathogenic bacteria.

4.2. Detection of barrier efficiency of particulate matter (≧0.3μm)

4.2.1. Test object

Cigarette smoke (≧0.3μm)

4.2.2. Test conditions

1) Ambient temperature: (23～27℃)

2) Environmental humidity: (40～60)%RH

4.2.3. Test equipment

Test chamber (30m ³ ), high concentration particle counter (SX-L301N), laser dust particle counter (LZJ-01D), particle diluter (SX-D100)

4.2.4. Machine running status

Turn on "high-end" and "high-pressure" during the test

4.2.5. Test steps

1) Place the sample machine to be inspected in a 30m ³ test chamber, adjust the sample machine to the test operation state, verify that it runs normally, and then close the sample machine.

2) Set a cigarette generator smoke release port at the middle of the sample machine head 20cm to simulate the breathing position of the patient, and set a sampling point 30cm above the cigarette generator smoke release port as the initial point of particle concentration, which is recorded as C0; in addition, Set sampling points around the prototype (front, right, left, and back) at a distance of 0.5m and a height of 1.5m, as the sampling points for particle concentration (front, right, left, and back), denoted as Ci(1, 2) , 3, ...).

3) Turn on the negative pressure screen, purify the air in the cabin, and start the temperature and humidity control device at the same time, so that the temperature and humidity in the cabin reach the state of the test.

4) Reduce the background concentration of particulate matter in the cabin to an appropriate level, turn off the negative pressure screen and the temperature and humidity device, and record the background concentration value.

5) Turn on the prototype purification function. After 10 minutes of stable operation, start the cigarette generator for 30 minutes continuously, sampling at each point at the same time, recording data every 2 minutes, and stopping sampling after 30 minutes of continuous testing, and the test is over.

6) Set up a control group, repeat steps 3) ~ 5), but do not turn on the prototype purification function.

4.2.6. Calculation formula

Natural barrier efficiency

(C0' is the average value of the initial point concentration of the control group, and Ci' is the average value of the concentration of each point in the four weeks of the control group);

Barrier efficiency

(C0 is the average value of the initial point concentration of the test group, and Ci is the average value of the concentration of each point in the four weeks of the test group).

Table 6 Detection data of particle barrier efficiency

It can be seen from the data in Table 6 that the particle blocking efficiency of the purification integrated isolation hospital bed of the present invention reaches more than 98.44%, which has a very good blocking effect on particles.

In summary, the purifying integrated hospital bed of the present invention can effectively block the air pollution caused by the gas exhaled by the patient, thereby achieving the effect of avoiding cross-infection between the patient and the patient, and between the patient and the healthy person.

5. Balance the airflow

The negative pressure forming device of the present invention is arranged on both sides of the purification device, so that the left and right sides of the main air duct and the auxiliary air duct produce uniform suction; the auxiliary air ducts on the left and right sides of the air inlet device have the same area, and are on the left and right sides. In the case of equal fan power, the negative pressure values of the auxiliary air ducts on the left and right sides are almost equal, which can stabilize the air flow; there is a flow plate at the bottom of the purification device to allow the gas from the purification device to evenly enter the two The negative pressure forming device on the side avoids the turbulence of the air flow inside the instrument; inside the negative pressure forming device, the rear part of the fan is equipped with an air deflector and a fan diversion ring. The air deflector can also guide the wind direction of the fan. Towards a fixed direction.

Detection method:

Single-side fan wind speed detection: The air inlet of the main air duct is equidistant from left to right at 9 detection points for wind speed detection, respectively 1a-9a, as shown in Figure 9-1, and the detection results are shown in Table 7.

Wind speed detection for fans installed on both sides: the main air duct air inlet is equidistant from left to right at 9 detection points for wind speed detection, respectively 1b-9b, as shown in Figure 9-2, and the detection results are shown in Table 7.

The fan models used in the single-sided fan detection and the double-sided fan detection as described above have the same speed.

Table 7 Comparison of wind speed balance of purification integrated hospital bed

It can be seen from Table 7 that the wind speed at the air inlet of the two-sided fan is about 2m/s; while for the single-sided fan, the wind speed on the side close to the fan reaches 2.76m/s, and the minimum wind speed at the air inlet on the side far from the fan is 1.23m/s , The wind speed is not balanced.

Fans installed on both sides can balance the wind speed at the air inlet position, avoid the diffusion of the patient's exhaled gas, and ensure that the contaminated gas is sucked into the negative pressure screen to the maximum.

As described above, the negative pressure screen is used in the field of hospital-sensing prevention and control, and is set on the patient's head to purify the air exhaled by the infected patient. The negative pressure screen is used in combination with the hospital bed to form a clean integrated hospital bed, and the head end of the hospital bed is placed on the front frame 11 of the main body. The purifying integrated hospital bed is used in the technical field of hospital induction prevention and control. When in use, the patient's head is close to the negative pressure screen, and the negative pressure screen purifies the gas exhaled by the infected patient.

In summary, the present invention can provide a negative pressure screen with compact structure, maximum absorption of pollutant gas, low noise, sufficient elimination, and airflow balance, and is used in the field of hospital sensing prevention and control, especially for the purification of integrated hospital beds. .

The described embodiments are merely examples in any sense, and the present invention shall not be interpreted in a limited manner based on the aforementioned embodiments. In addition, all equivalent modifications and changes belonging to the scope of the claims are within the scope of the present invention.

Claims (10)

1. A negative pressure screen, characterized in that the negative pressure screen includes a main body welded part, an air inlet device, a purification device and a negative pressure forming device;

   The main body welding piece includes a main body front frame and a main body middle frame, and the main body front frame and the main body middle frame are integrally connected;

   The air inlet device is located in the frame of the main body, and the air inlet device is a plate-shaped frame structure;

   The purification device and the negative pressure forming device are both installed inside the front frame of the main body, and there are two negative pressure forming devices, which are respectively installed on the left and right sides of the purification device.
2. The negative pressure screen according to claim 1, characterized in that,

   The air inlet device includes a ventilation hole plate, a ventilation duct and an air duct cover plate;

   The ventilation hole plate, the ventilation duct and the air duct cover are tightly connected in sequence from front to back, and are installed in the central frame of the main body.
3. The negative pressure screen according to claim 2, characterized in that,

   The middle position of the vent plate is provided with a middle air inlet, and the edge of the vent plate is provided with side air inlets; the vent duct and the vent plate are sealed and covered to form an open half-frame pipe; the side inlet The air hole is located inside the ventilation duct, and the middle air inlet is located outside the ventilation duct;

   The inner side wall of the ventilation duct is enclosed in a hollow funnel shape, and the opening of the funnel is downward; the air outlet of the ventilation duct is provided with an air duct baffle.
4. The negative pressure screen according to claim 3, wherein the ventilation duct has two air outlets, and the areas of the air outlets are equal.
5. The negative pressure screen according to claim 3, wherein the ratio of the area of the opening of the funnel to the area of the air outlet is 3:1.
6. The negative pressure screen according to claim 3, wherein the inner side wall is composed of a double-layer perforated wall surface, and a sound insulation material is placed in the middle of the double-layer perforated wall surface.
7. The negative pressure screen according to claim 1, wherein the purification device is provided with a primary effect filter, an electrostatic device, and an ozone decomposition network in order from top to bottom, and is characterized in that a flow sharing plate is installed at the bottom of the purification device.
8. 8. The negative pressure screen according to claim 7, wherein the current-sharing plate is a strip-shaped plate with a fold-line cross-section.
9. The application of the negative pressure screen according to any one of claims 1-8 in the field of hospital sense prevention and control.
10. A purification integrated hospital bed, characterized in that the hospital bed comprises a bed body and the negative pressure screen of any one of claims 1-8, and the head end of the bed body is placed on the front frame of the main body of the negative pressure screen on.

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