A ventilator

Abstract

This utility model discloses a ventilator, which includes an air inlet, a first air inlet channel, and a second air inlet channel. The first air inlet channel is connected to the air inlet. The second air inlet channel includes a first part and a second part arranged in an L-shape. The first air inlet channel and the first part are stacked vertically. The end of the first air inlet channel away from the air inlet is connected to the first part. Both the first and second air inlet channels are located on the periphery of the fan housing. This utility model optimizes the air intake duct of a small ventilator, improves the noise reduction effect of the ventilator, and provides a better experience for the patient.

Description

Technical Field

[0001] This utility model relates to a ventilator and belongs to the field of ventilator technology. Background Technology

[0002] In modern clinical medicine, ventilators, as an effective means of artificially replacing spontaneous ventilation, are widely used in respiratory failure caused by various reasons, anesthetic respiratory management during major surgery, respiratory support therapy, and emergency resuscitation, occupying a very important position in the field of modern medicine. A ventilator is a crucial medical device that can prevent and treat respiratory failure, reduce complications, and save and prolong patients' lives.

[0003] Most existing ventilators assist patients' breathing by using a fan to move air. However, existing ventilators generate significant vibration and noise during use, affecting patient experience, especially with smaller ventilators. Utility Model Content

[0004] In order to reduce the noise generated by the airflow inside the ventilator and improve the user experience, this utility model provides a ventilator, the specific technical solution of which is as follows.

[0005] A ventilator, characterized in that it includes an air inlet, a first air inlet channel, and a second air inlet channel;

[0006] The first air intake channel is connected to the air inlet; the second air intake channel includes a first part and a second part arranged in an L-shape, the first air intake channel and the first part are stacked vertically, and the end of the first air intake channel away from the air inlet is connected to the first part; both the first air intake channel and the second air intake channel are located on the periphery of the wind turbine compartment.

[0007] The above technical solution is adopted in which the first air intake channel and the first part of the second air intake channel are stacked vertically, which extends the air intake channel; the second air intake channel is set in an L-shape, which further extends the air intake channel, thereby achieving a better noise reduction effect; the first air intake channel and the second air intake channel are both located on the periphery of the fan compartment, which is conducive to making full use of the internal space of the ventilator without increasing the volume of the small ventilator.

[0008] Furthermore, it also includes a transition chamber and a fan compartment chamber. The transition chamber is located above the second air inlet channel, and the transition chamber and the second air inlet channel are connected by a vertically arranged wind resistance pipe. The fan compartment chamber is located inside the fan compartment, and the fan compartment chamber is connected to the transition chamber.

[0009] Furthermore, the device also includes a fan housing cover, a ventilator base, and a fan vibration damping and noise reduction component. The fan vibration damping and noise reduction component is made of a flexible material and is sandwiched between the fan housing cover and the ventilator base. The fan housing is formed by the fan housing cover and the ventilator base. The fan vibration damping and noise reduction component provides flexible support for the fan body, helping to reduce vibration and noise. Preferably, the flexible material is at least one of silicone, TPE, TPR, polyurethane, neoprene rubber, polypropylene, fluororubber, polysulfide rubber, or nitrile rubber.

[0010] Furthermore, the fan vibration damping and noise reduction component includes an air duct partition wall located outside the fan housing. The first air inlet channel is located between the air duct partition wall and the fan housing cover; the first portion of the second air inlet channel is located between the air duct partition wall and the ventilator base. That is, the flexible air duct partition wall serves as the partition wall between the first and second air inlet channels, simplifying the assembly process and contributing to noise reduction.

[0011] Further, the fan vibration damping and noise reduction component includes a noise reduction chamber wall located outside the fan housing. The noise reduction chamber wall and the fan housing cover form a noise reduction chamber. The noise reduction chamber wall has several through holes, and a second portion of the second air inlet channel communicates with the noise reduction chamber through the through holes. The second portion of the second air inlet channel is located between the noise reduction chamber wall and the ventilator base. Preferably, the noise reduction chamber includes an adjacent first noise reduction chamber and a second noise reduction chamber. Both the first noise reduction chamber and the second noise reduction chamber communicate with the second portion of the second air inlet channel through the through holes. The volume of the first noise reduction chamber is smaller than the volume of the second noise reduction chamber.

[0012] Furthermore, the ventilator base is provided with a guide strip, which is located within the first part of the second air inlet channel and extends from the side wall of the ventilator base towards the second part of the second air inlet channel. Preferably, three guide strips are arranged in parallel, with the middle guide strip being higher than the two side guide strips.

[0013] Furthermore, a vertically extending guide column is also provided within the second portion of the second air inlet channel, the guide column being located directly below the air resistance pipe; the guide column includes a baffle, a first guide vane, and a second guide vane; the connection point between the first portion and the second portion is called the connection end, the first guide vane being fixed to the side of the baffle facing the connection end, and the second guide vane being fixed to the side of the baffle away from the connection end. Preferably, a plurality of first guide vanes are arranged in parallel, and a plurality of second guide vanes are arranged radially. Preferably, the number of first guide vanes is greater than the number of second guide vanes.

[0014] Compared with the prior art, this utility model has the following beneficial effects.

[0015] 1. The air intake duct has been extended in the small ventilator, which improves the noise reduction effect of the ventilator and makes the treatment experience better;

[0016] 2. The fan vibration damping and noise reduction components not only reduce the vibration and noise of the fan, but also serve as the partition wall between the first and second air intake channels. This simplifies the assembly process while facilitating the extension of the air intake duct.

[0017] 3. By utilizing the fan vibration damping and noise reduction components and the fan shroud cover above the second air inlet channel, a first noise reduction chamber and a second noise reduction chamber are formed, which reduces noise and simplifies the assembly process.

[0018] 4. By setting up guide strips and guide columns, airflow turbulence is significantly reduced, which helps to reduce noise. Attached Figure Description

[0019] Figure 1 This is an exploded view of the ventilator of this utility model;

[0020] Figure 2 This is a schematic diagram of the ventilator base;

[0021] Figure 3 yes Figure 2 Enlarged view of region A in the middle;

[0022] Figure 4 This is a bottom view of the wind turbine nacelle cover;

[0023] Figure 5 This is a schematic diagram of a fan vibration damping and noise reduction component;

[0024] Figure 6 This is a longitudinal cross-sectional view of the ventilator;

[0025] Figure 7 yes Figure 6 A schematic diagram of airflow in cross-sectional view;

[0026] Figure 8 This is another longitudinal cross-sectional view of the ventilator;

[0027] Figure 9 This is a schematic diagram of airflow in a cross-sectional view of a ventilator.

[0028] Figure 10 This is a schematic diagram of the basic structure of a Helmholtz resonant cavity;

[0029] Figure 11 This is the sound pressure cloud map without the addition of two anechoic chambers (simulated noise frequency is 1055HZ);

[0030] Figure 12 It is a sound pressure cloud map with two anechoic chambers added (simulating noise frequency of 1055HZ);

[0031] Figure 13 This is the sound pressure cloud map without the addition of two anechoic chambers (simulated noise frequency is 1922HZ);

[0032] Figure 14 It is a sound pressure cloud map with two anechoic chambers added (simulating noise frequency of 1922HZ);

[0033] Figure 15 This is a velocity contour map of the airway cross section when the three guide strips are at the same height;

[0034] Figure 16 This is a velocity contour map of the airway cross section when the middle guide bar is higher;

[0035] Figure 17 This is a turbulent kinetic energy cloud diagram of the air passage cross-section when the three guide strips are at the same height.

[0036] Figure 18 This is a turbulent kinetic energy cloud diagram of the air passage cross-section when the middle guide bar is higher;

[0037] Figure 19 This is a turbulent kinetic energy cloud diagram of the axial cross-section of a drag duct without a guide column;

[0038] Figure 20 It is a turbulent kinetic energy cloud diagram of the axial cross section of the wind resistance pipe using a guide column.

[0039] In the diagram: 1. Ventilator top cover; 2. Ventilator base; 2.1. Air inlet; 2.2. Guide strip; 3. Humidifier; 4. Fan vibration damping and noise reduction component; 4. Ventilation channel; 4.1. Airway partition wall; 4.2. Negative chamber wall; 4.3. Through hole; 4.3.1. Air resistance pipe mounting hole; 4.4. Fan compartment top cover; 5. Fan compartment side wall; 5.1. Connecting hole; 5.2. Fan body; 6. Fan compartment; 7. Fan compartment upper chamber; 7.1. Fan compartment lower chamber; 7.2. First air inlet channel; 8. Second air inlet channel; 9. First part; 9.1. Second part; 9.2. Transition chamber; 10. Fan compartment chamber; 11. Air resistance pipe; 12. First anechoic chamber; 13. Second anechoic chamber; 14. Guide column; 15. Baffle; 15.1. First guide vane; 15.2. Second guide vane; 15.3. Detailed Implementation

[0040] The present invention will now be described in further detail with reference to the accompanying drawings.

[0041] See Figures 1-9 The ventilator includes a ventilator cover 1, a ventilator base 2, and a humidifier 3. A fan vibration damping and noise reduction component 4, a fan chamber cover 5, and a fan body 6 are provided between the ventilator cover 1 and the ventilator base 2.

[0042] The fan vibration damping and noise reduction component 4 is made of flexible material and is sandwiched between the fan housing cover 1 and the ventilator base 2. The fan housing 7 is formed by the fan housing cover 1 and the ventilator base 2. The fan body 6 is fixed by the fan vibration damping and noise reduction component 4 and the fan housing cover 5. The fan body 6 is housed within the fan housing 7. An upper chamber 7.1 is formed between the fan vibration damping and noise reduction component 4 and the fan housing cover 1, and a lower chamber 7.2 is formed between the fan vibration damping and noise reduction component 4 and the ventilator base 2. The fan vibration damping and noise reduction component 4 has several ventilation channels 4.1, which connect the upper chamber 7.1 and the lower chamber 7.2 of the fan housing. The fan vibration damping and noise reduction component 4 provides flexible support for the fan body 6, which helps to reduce vibration and noise. Preferably, the flexible material is at least one of silicone, TPE, TPR, polyurethane, chloroprene rubber, polypropylene, fluororubber, polysulfide rubber or nitrile rubber.

[0043] The ventilator base 2 is provided with an air inlet 2.1. The air intake channel of the ventilator includes a first air intake channel 8, a second air intake channel 9, a transition chamber 10, and a fan chamber 11.

[0044] The first air inlet channel 8 is connected to the air inlet 2.1; the second air inlet channel 9 includes a first part 9.1 and a second part 9.2 arranged in an L-shape. The first air inlet channel 8 and the first part 9.1 are stacked vertically. The end of the first air inlet channel 8 away from the air inlet 2.1 is connected to the first part 9.1; both the first air inlet channel 8 and the second air inlet channel 9 are located on the periphery of the fan compartment 7.

[0045] The transition chamber 10 is located above the second air inlet channel 9, and the transition chamber 10 and the second air inlet channel 9 are connected by a vertically arranged air resistance pipe 12; the fan compartment chamber 11 is located inside the fan compartment 7, and the fan compartment chamber 11 includes the aforementioned upper fan compartment chamber 7.1 and lower fan compartment chamber 7.2; the fan compartment cover 5 has a fan compartment side wall 5.1, and a connecting hole 5.2 is provided on the fan compartment side wall 5.1, and the upper fan compartment chamber 7.1 of the fan compartment chamber 11 is connected to the transition chamber 10 through the connecting hole 5.2; wherein, the air resistance pipe 12 is a conventional component in the ventilator, and an air resistance plate (not shown) is usually provided inside the air resistance pipe 12.

[0046] In this design, the air duct partition wall 4.2 of the fan vibration damping and noise reduction component 4 is located outside the fan housing 7, and the first air inlet channel 8 is located between the air duct partition wall 4.2 and the fan housing cover 1; the first part 9.1 of the second air inlet channel 9 is located between the air duct partition wall 4.2 and the ventilator base 2. That is, the flexible air duct partition wall 4.2 serves as the partition wall between the first air inlet channel 8 and the first part 9.1 of the second air inlet channel 9, which not only simplifies the assembly process but also helps reduce noise. The fan vibration damping and noise reduction component 4 also has a resistance tube mounting hole 4.4 through which the resistance tube 12 passes.

[0047] The anechoic chamber wall 4.3 of the fan vibration damping and noise reduction component 4 is located outside the fan housing 7. The anechoic chamber wall 4.3 and the fan housing cover 5 form an anechoic chamber. The anechoic chamber wall 4.3 has several through holes 4.3.1. The second part 9.2 of the second air inlet channel 9 and the anechoic chamber are connected through the through holes 4.3.1. The second part 9.2 of the second air inlet channel 9 is located between the anechoic chamber wall 4.3 and the ventilator base 2. Preferably, the anechoic chamber includes an adjacent first anechoic chamber 13 and a second anechoic chamber 14. Both the first anechoic chamber 13 and the second anechoic chamber 14 are connected to the second part 9.2 of the second air inlet channel 9 through the through holes 4.3.1. The volume of the first anechoic chamber 13 is smaller than the volume of the second anechoic chamber 14, which can reduce noise of different frequencies. The noise reduction principle of the first anechoic chamber 13 and the second anechoic chamber 14 utilizes the Helmholtz resonant cavity principle.

[0048] The basic structure of a Helmholtz resonator is as follows: Figure 10 As shown, the structure consists of a neck and a main cavity. In this embodiment, the through hole 4.3.1 constitutes the neck, and the first anechoic chamber 13 (or the second anechoic chamber 14) constitutes the main cavity. Each Helmholtz resonant cavity has a natural frequency. When the external sound pressure reaches near this frequency, the air column at the bottleneck moves violently back and forth, rubbing against the neck wall and converting sound energy into heat energy for dissipation, thereby achieving a sound absorption effect.

[0049] For example, the volume of the first anechoic chamber 13 is set to 19000 mm. 3 The volume of the second anechoic chamber 14 is set to 5910 mm. 3 .

[0050] The formula for calculating the natural frequency f of a Helmholtz resonator is:

[0051]

[0052] Where L is the length of the neck of the resonant cavity, A is the cross-sectional area of ​​the neck of the resonant cavity, V is the volume of the main cavity of the resonant cavity, and C is the speed of sound.

[0053] Since the noise reduction capabilities of the Helmholtz resonator are roughly symmetrical on both sides of the natural frequency, in this embodiment, the natural frequency of the first anechoic chamber 13 can be set in the range of 800-1300 Hz, and the natural frequency of the second anechoic chamber 14 can be set in the range of 1800-2100 Hz.

[0054] Based on the measured noise spectrum of the fan, the sound pressure level is relatively high at 1000Hz and 2000Hz. Therefore, the natural frequency of the first anechoic chamber 13 is designed to be f1 = 1000Hz, and the natural frequency of the second anechoic chamber 14 is designed to be f2 = 2000Hz. Simulation calculations show that the natural frequency of the first anechoic chamber is 1055Hz, and the natural frequency of the second anechoic chamber is 1922Hz, which is basically consistent with the calculated results.

[0055] At frequencies of 1055Hz and 1922Hz, resonance occurs within the anechoic cavity, such as... Figures 11-14 As shown, 1055 Hz corresponds to the first anechoic chamber 13, and 1922 Hz corresponds to the second anechoic chamber 14. At the sound field exit section, the sound pressure intensity decreased by 23% and 15%, respectively. Figures 11-14 In the diagram, the darker the blue, the stronger the sound pressure and the higher the noise. After adding the anechoic chamber, the sound pressure in the P and Q regions of the sound pressure diagram is significantly reduced, indicating that the noise is effectively reduced.

[0056] In a preferred embodiment, such as Figure 6 , Figure 8 As shown, the ventilator base 2 is provided with a guide strip 2.2, which is located within the first part 9.1 of the second air inlet channel 9, and extends from the side wall of the ventilator base 2 towards the second part 9.2 of the second air inlet channel 9. Preferably, three guide strips 2.2 are arranged in parallel, with the middle guide strip 2.2 being higher than the two side guide strips 2.2; the purpose is to make the airflow velocity at the outlet of the three guide strips 2.2 similar, avoiding excessive velocity difference that could cause airflow separation and generate new noise sources. Figure 15 The velocity contour plot of the airway cross section at the same height is shown in Figure 2.2 for three guide vanes. Figure 16 The velocity contour plot of the airway section at a higher height in the middle of guide strip 2.2; from Figure 15 It can be observed that the airflow velocity in the right air intake is significantly higher than that in the left air intake when the guide bar is of equal height. However, in the air intake cross-section with the middle guide bar heightened design, the velocity difference between the four air intakes is very small. Figure 16 As shown. Figure 17 This is a turbulent kinetic energy cloud map of the air passage cross-section using a guide vane with equal height design. Figure 18 By using the design of raising the middle guide strip in the cross-section of the air passage turbulent kinetic energy cloud diagram, a significant decrease in turbulent kinetic energy can be observed.

[0057] In a preferred embodiment, such as Figure 2 , Figure 3 As shown, a vertically extending guide column 15 is also provided in the second part 9.2 of the second air inlet channel 9, located directly below the wind resistance pipe 12. The guide column 15 includes a baffle 15.1, a first guide vane 15.2, and a second guide vane 15.3. The connection between the first part 9.1 and the second part 9.2 is called the connection end 9.3. The first guide vane 15.2 is fixed to the side of the baffle 15.1 facing the connection end 9.3, and the second guide vane 15.3 is fixed to the side of the baffle 15.1 facing away from the connection end 9.3. Preferably, a plurality of first guide vanes 15.2 are arranged in parallel, and a plurality of second guide vanes 15.3 are arranged radially. Preferably, the number of first guide vanes 15.2 is greater than the number of second guide vanes 15.3.

[0058] The first guide vane 15.2 is located on the windward side, and the second guide vane 15.3 is located on the windward side. All the first guide vanes 15.2 are perpendicular to the baffle 521, and some of the second guide vanes 15.3 are inclined relative to the baffle 15.1. There are more first guide vanes 15.2 than second guide vanes 15.3. On the one hand, the flow rate entering the wind resistance pipe 12 through the first guide vane 15.2 is larger, and the turbulent kinetic energy is also greater. Therefore, more guide vanes are needed for rectification and turbulence elimination. On the other hand, appropriately increasing the resistance at the front end can guide the airflow to the rear end. However, the flow rate entering the wind resistance pipe through the direction of the second guide vane 15.3 is smaller, and the turbulent kinetic energy is also smaller. If too many second guide vanes 15.3 are added, it will not only fail to significantly reduce the turbulent kinetic energy, but will also significantly increase the air resistance in the direction of the second guide vane 15.3, increasing the fan load. Before entering the transition chamber 10 through the second part 9.2 of the second air intake channel 9, the external air will pass through the guide strip 2.2 and the guide column 15. The guide strip 2.2 can effectively reduce the turbulent noise originally generated at the 180° turn by rectifying the flow. The guide column 15 can restrict the flow of air in the direction outside the axial direction of the wind resistance pipe 12 by dividing the air intake section of the wind resistance pipe 12, thereby reducing turbulent kinetic energy and reducing pressure fluctuation at the pressure port. Figure 19 The image shows the turbulent kinetic energy contour plot of the axial section of the drag duct 12 without the guide column 15. Figure 20 The image shows the turbulent kinetic energy cloud diagram of the axial section of the drag tube 12 with the guide column 15. It can be seen that the turbulent kinetic energy inside the drag tube 12 decreases significantly after the guide column 15 is adopted.

[0059] like Figure 7 , Figure 9As shown, the air intake sequence of the ventilator in this embodiment is as follows: external air enters the first air intake channel 8 through the air intake port 2.1, and enters the first part 9.1 of the second air intake channel 9 at the end of the first air intake channel 8. It turns into the second part 9.2 in the first part 9.1, then enters the transition chamber 10 through the air resistance pipe 12, and then enters the upper chamber 7.1 of the fan chamber 11 through the connecting hole 5.2. Then it enters the lower chamber 7.2 of the fan chamber through the ventilation channel 4.1. The fan body 6 pressurizes the air in the lower chamber 7.2 of the fan chamber and delivers it to the downstream humidifier 3 to increase the humidity, and then discharges it to the outside of the ventilator. The first air intake channel 8 and the first part 9.1 of the second air intake channel 9 are stacked vertically, which extends the air intake channel; the second air intake channel 9 is L-shaped, which further extends the air intake channel, thereby achieving a better noise reduction effect; the first air intake channel 8 and the second air intake channel 9 are both located on the periphery of the fan compartment 7, which is conducive to making full use of the internal space of the ventilator without increasing the volume of the small ventilator.

[0060] The embodiments of the present invention have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention is not limited to the specific embodiments described above; these embodiments are merely illustrative and not limiting. Those skilled in the art, under the guidance of the present invention, can make many modifications without departing from the spirit and scope of the claims, and all such modifications fall within the protection scope of the present invention.

Claims

1. A ventilator, characterized in that, It includes an air inlet (2.1), a first air inlet channel (8), and a second air inlet channel (9); The first air inlet channel (8) is connected to the air inlet (2.1); the second air inlet channel (9) includes a first part (9.1) and a second part (9.2) in an L-shaped layout, the first air inlet channel (8) and the first part (9.1) are stacked vertically, and the end of the first air inlet channel (8) away from the air inlet (2.1) is connected to the first part (9.1); the first air inlet channel (8) and the second air inlet channel (9) are both located on the periphery of the fan shack (7).

2. A ventilator according to claim 1, characterized in that, It also includes a transition chamber (10) and a fan compartment chamber (11). The transition chamber (10) is located above the second air inlet channel (9). The transition chamber (10) and the second air inlet channel (9) are connected by a vertically arranged wind resistance pipe (12). The fan compartment chamber (11) is located inside the fan compartment (7). The fan compartment chamber (11) is connected to the transition chamber (10).

3. A ventilator according to claim 1, characterized in that, It also includes a fan housing cover (5), a ventilator base (2) and a fan vibration damping and noise reduction component (4). The fan vibration damping and noise reduction component (4) is made of flexible material. The fan vibration damping and noise reduction component (4) is sandwiched between the fan housing cover (5) and the ventilator base (2). The fan housing (7) is formed by the fan housing cover (5) and the ventilator base (2). The flexible material is at least one of silicone, TPE, TPR, polyurethane, neoprene rubber, polypropylene, fluororubber, polysulfide rubber or nitrile rubber.

4. A ventilator according to claim 3, characterized in that, The fan vibration damping and noise reduction component (4) includes an airway partition wall (4.2), which is located outside the fan housing (7). The first air inlet channel (8) is located between the airway partition wall (4.2) and the fan housing cover (5). The first part (9.1) of the second air inlet channel (9) is located between the airway partition wall (4.2) and the ventilator base (2).

5. A ventilator according to claim 3, characterized in that, The fan vibration damping and noise reduction component (4) includes a noise reduction chamber wall (4.3), which is located outside the fan housing (7). The noise reduction chamber wall (4.3) and the fan housing cover (5) form a noise reduction chamber. The noise reduction chamber wall (4.3) has several through holes (4.3.1). The second part (9.2) of the second air inlet channel (9) and the noise reduction chamber are connected through the through holes (4.3.1). The second part (9.2) of the second air inlet channel (9) is located between the noise reduction chamber wall (4.3) and the ventilator base (2).

6. A ventilator according to claim 5, characterized in that, The anechoic chamber includes an adjacent first anechoic chamber (13) and a second anechoic chamber (14). The first anechoic chamber (13) and the second anechoic chamber (14) are connected to the second part (9.2) of the second air inlet channel (9) through the through hole (4.3.1). The volume of the first anechoic chamber (13) is smaller than the volume of the second anechoic chamber (14).

7. A ventilator according to claim 3, characterized in that, The ventilator base (2) is provided with a guide strip (2.2), which is located in the first part (9.1) of the second air inlet channel (9) and extends from the side wall of the ventilator base (2) to the second part (9.2) of the second air inlet channel (9); three guide strips (2.2) are arranged in parallel, and the middle guide strip (2.2) is higher than the two side guide strips (2.2).

8. A ventilator according to claim 2, characterized in that, A vertically extending guide column (15) is also provided in the second part (9.2) of the second air inlet channel (9). The guide column (15) is located directly below the wind resistance pipe (12). The guide column (15) includes a baffle (15.1), a first guide plate (15.2) and a second guide plate (15.3). The connection between the first part (9.1) and the second part (9.2) is called the connection end. The first guide plate (15.2) is fixed to the side of the baffle (15.1) facing the connection end, and the second guide plate (15.3) is fixed to the side of the baffle (15.1) away from the connection end.

9. A ventilator according to claim 8, characterized in that, A plurality of the first guide vanes (15.2) are arranged in parallel, and a plurality of the second guide vanes (15.3) are arranged radially.

10. A ventilator according to claim 9, characterized in that, The number of the first guide vanes (15.2) is greater than the number of the second guide vanes (15.3).

Images