JP2010096135A - Blower with sound attenuation box - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blower with a sound attenuation box thinning a machine body while securing air quantity by reducing a pressure loss at an air duct, increasing strength, and improving maintenance properties by devising arrangement and a fixing method of a casing and a drain pan. <P>SOLUTION: A double suction type centrifugal blower 9 is provided in a box shape machine body 3. An inspection opening 16 is formed at one surface of the machine body 3 opposing a casing suction port 12. A machine body bottom opening 17 having one surface of the machine body 3 not opposing the casing suction port 12 as a bottom surface and an opening is formed. The drain pan 18 is connected to the machine body bottom opening 17. A casing base 19 is fixed on a bottom surface of the casing side plate 13. The casing base 19 connects the inner surface opposing the machine body 3. Consequently, the blower with the sound attenuation box reducing pressure loss at the air duct 8, thinning the machine body 3 while securing an air quantity, increasing strength, and improving maintenance properties is provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a blower with a silencer box that is used by incorporating a blower inside a silencer box such as a ventilation fan.

  Conventionally, as this type of fan with a sound deadening box, the casing suction port of the single suction type blower is arranged in the body so as to face the drain pan side of the bottom surface, and a wind guide plate that partitions the air path in the body from the drain pan is provided. Are known (for example, see Patent Document 1).

  Hereinafter, the blower with the sound deadening box will be described with reference to FIGS. 8 and 9.

  As shown in FIGS. 8 and 9, the ceiling 101 has a box-shaped airframe 106 installed by connecting a suction-side duct 103 to the airframe suction port 102 and a blowout-side duct 105 connected to the airframe outlet 104. On the side of 106, a machine body inlet 102 is provided on the suction side for sucking air, and a body outlet 104 is provided on the outlet side for blowing air. Inside the body 106, a casing 107, a motor 108, a casing suction port 109, and a single suction are provided. A single-suction centrifugal blower 111 having a mold impeller 110 is provided, and a drain pan 112 facing the casing suction port 109 is detachably screwed to the desired 106, and the casing suction port 109 faces the drain pan 112 side of the bottom surface. The air guide plate 114 is arranged so as to partition the air passage 113 in the airframe 106 from the drain pan 112.

Then, when the single suction centrifugal blower 111 is operated, the air in the room 115 is guided by the air guide plate 114 through the suction duct 103, toward the casing suction port 109, via the single suction centrifugal blower 111. It passes through the blowout duct 105 and is exhausted to the outdoor 116. A ceiling inspection port 118 is provided in the ceiling material 117 immediately below the drain pan 112.
Japanese Patent Laid-Open No. 4-309738

  In such a conventional blower with a sound deadening box, a wind guide plate is provided to smoothly flow an air flow toward the casing suction port. To reduce the pressure loss in the air passage, the casing suction port and the wind guide plate are provided. It is necessary to ensure a sufficient distance, and there is a problem that the size of the aircraft increases.

  In addition, when the motor is maintained, the drain pan is removed from the airframe, the air guide plate is then removed, the impeller needs to be removed from the casing suction port, and the motor needs to be checked.

  In addition, since it is necessary to take out the drain pan from the ceiling inspection port, the ceiling inspection port needs to be larger than the drain pan, and work that faces upward from the room is required, so there is a problem of poor maintainability. is there.

  The present invention solves such a conventional problem. By devising the arrangement and fixing method of the casing and the drain pan, the airframe is thinned while reducing the pressure loss in the air passage and ensuring the air volume. An object of the present invention is to provide a fan with a sound deadening box that can improve strength and maintainability.

  In order to achieve the above object, the blower with a sound deadening box of the present invention includes a double suction centrifugal blower inside a box-shaped airframe provided with a fuselage suction port and a fuselage blowout port facing each other, and the double suction centrifugal The blower is provided with a casing side plate provided with a discharge port facing the airframe outlet, a spiral scroll, and a casing suction port on both sides, and is driven by a motor that fixes both suction impellers in the vicinity of the casing suction port, An inspection opening is provided on one surface of the airframe facing the casing suction port, an airframe bottom opening is formed with the one surface of the airframe not facing the casing suction port as a bottom surface, and a drain pan is provided in the airframe bottom opening. A blower with a silencer box connected, wherein a casing base for fixing both the suction type centrifugal fans to the fuselage is fixed to a bottom surface of the casing side plate, Base is obtained by a structure for connecting an inner surface facing the fuselage.

  In addition, the other means includes a casing base lower surface air passage that passes through the drain pan, passes through the drain pan and passes through the lower surface of the casing base, and then faces the both suction centrifugal fans. It is assumed that the air flows into the casing suction port as a tongue direction airflow having an angle inclined toward the suction center of the suction type impeller.

  Another means is configured such that the cross section of the casing base has an L-shaped bent shape.

  Further, the other means is configured to arrange the casing base in a direction from the airframe inlet to the airframe outlet.

  Another means is configured to project the L-shaped bending direction of the cross section of the casing base toward the drain pan side.

  Another means is that the casing bases are arranged on the casing side plates on both sides of both suction centrifugal fans, and the L-shaped bending height of the section of the casing base on the side of the casing side plate to which the motor is fixed is set to the other side. It is set as the structure enlarged with respect to the L-shaped bending height of a casing base.

  In addition, the other means is configured to provide a spatial distance for cleaning by inserting a hand between the casing base and the drain pan.

  Further, the other means is configured such that the opposite side of the inspection opening of the fuselage is fixed so that the drain pan and the fuselage can be fitted together, and the other surface of the fuselage is fixed by screwing the joint between the drain pan and the fuselage. Is.

  The other means is configured such that a casing sound absorbing material is disposed on the casing side plate, and the casing sound absorbing material is supported in contact with the casing base.

  Further, the other means is configured such that the airframe sound absorbing material is disposed on the inner surface of the airframe, and the airframe sound absorbing material is supported in contact with the casing base.

  According to the present invention, a double-suction centrifugal blower is provided inside a box-shaped airframe having a fuselage inlet and a fuselage outlet facing each other, and the dual-suction centrifugal blower is a discharge outlet facing the fuselage outlet. One side of the body facing the casing suction port, which is provided with a casing side plate provided with a spiral scroll and a casing suction port on both sides, driven by a motor in which both suction impellers are fixed in the vicinity of the casing suction port. A blower with a muffler box provided with an opening for inspection, provided with a bottom opening of the body that has an opening on one side of the body that does not face the casing suction port, and a drain pan connected to the bottom opening of the body, A casing base for fixing both suction type centrifugal blowers to the airframe is fixed to the bottom surface of the casing side plate, and the casing base connects opposite inner surfaces of the airframe. To provide a blower with a sound deadening box that can reduce the pressure loss in the air passage and ensure the air volume while reducing the thickness of the airframe, improving the strength, and improving the maintainability. Can do.

  The air flow from the air inlet of the airframe is provided with a casing base lower surface air passage that passes through the drain pan and passes through the lower surface of the casing base and then goes to the double suction centrifugal blower. By adopting a configuration that flows into the casing suction port as an airflow in the tongue direction with an angle inclined toward the suction center, it is possible to reduce the pressure loss in the air passage and secure the air volume while reducing the thickness of the aircraft. It is possible to provide a blower with a silencing box that has an effect of improving the pressure.

  In addition, by adopting a configuration in which the cross section of the casing base is bent in an L shape, the airframe can be thinned and the strength can be improved while reducing the pressure loss in the air passage and securing the air volume. A blower with a box can be provided.

  In addition, the silencer box has the effect of reducing the pressure loss in the air passage and ensuring the air volume by reducing the pressure loss in the air passage by arranging the casing base in the direction from the air inlet to the air outlet. An attached blower can be provided.

  In addition, by adopting a configuration in which the L-shaped bending direction of the cross section of the casing base protrudes toward the drain pan, a sound deadening box with an effect of reducing the pressure loss in the air passage and ensuring the air volume can be achieved. A blower can be provided.

  Further, the casing base is arranged on the casing side plates on both side surfaces of both suction centrifugal fans, and the L-shaped bending height of the section of the casing base on the casing side plate side to which the motor is fixed is set to the L-shape of the other casing base. A fan with a sound deadening box that can reduce the pressure loss in the air passage and secure the air volume while reducing the pressure loss in the air passage and can improve the strength is provided by adopting a configuration that increases the bending height. be able to.

  In addition, the present invention provides a blower with a sound deadening box that has a simple structure and can be improved in maintainability by providing a space for cleaning by inserting a hand between the casing base and the drain pan. be able to.

  Further, the opposite side of the inspection opening of the aircraft is fixed so that the drain pan and the aircraft can be fitted together, and the other surfaces of the aircraft are configured so that the connection between the drain pan and the aircraft is fixed with screws. It is possible to provide a blower with a sound deadening box which can be structured and can be improved in maintainability.

  In addition, by arranging a casing sound-absorbing material on the casing side plate and supporting the casing sound-absorbing material in contact with the casing base, it is possible to provide a fan with a sound deadening box that has a simple structure and can reduce noise. Can be provided.

  Also, a fan with a sound deadening box that has a simple structure and is capable of reducing noise by arranging a sound absorbing material on the inner surface of the fuselage and supporting the sound absorbing material in contact with a casing base. Can be provided.

  The blower with a sound deadening box according to claim 1 of the present invention is provided with a double suction centrifugal blower inside a box-shaped airframe in which a fuselage suction port and a fuselage blowout port are provided facing each other, A casing side plate provided with a discharge port facing the fuselage outlet, a spiral scroll and a casing suction port is provided on both sides, and both suction impellers are driven by a motor fixed in the vicinity of the casing suction port, and the casing suction A silencer provided with an inspection opening on one surface of the airframe facing the mouth, an airframe bottom opening opened with one surface of the airframe not facing the casing suction port as a bottom surface, and a drain pan connected to the airframe bottom opening A blower with a box, wherein a casing base for fixing the both suction type centrifugal blowers to the airframe is fixed to a bottom surface of the casing side plate, It is configured to connect the opposite inner surfaces of the fuselage, and since the drain pan is also used as a drain receiving part and an air passage, the air passage area inside the aircraft is increased without increasing the fuselage, and airflow collision loss is reduced. In addition, since the casing base supports the bottom surface of the casing side plate, the heavy suction centrifugal fan can be firmly connected to the fuselage, and the inspection opening and the fuselage bottom opening communicate with each other. The operation | work which removes is unnecessary and it has the effect | action that the drain pan inner surface can be confirmed easily from the opening part for inspection.

  The air flow from the air inlet of the airframe is provided with a casing base lower surface air passage that passes through the drain pan and passes through the lower surface of the casing base and then goes to the double suction centrifugal blower. It is configured to flow into the casing suction port as a tongue direction airflow that is inclined toward the suction center, and the tongue direction airflow that has passed through the drain pan is an inflow airflow in the inlet direction of the blades of both suction type impellers Therefore, the air velocity at the blade inlet increases and the static pressure can be increased.

  Moreover, it is set as the structure which makes the cross section of a casing base into an L-shaped bending shape, and since the intensity | strength of casing base itself was improved by providing the L-shaped bending to a casing base, it can be said that both suction type centrifugal blowers can be firmly connected to an airframe. Has an effect.

  Further, the casing base is arranged in a direction from the airframe inlet to the airframe outlet, and the L-shaped bending of the casing base is in a direction along the airflow direction in the airframe from the airframe inlet to the airframe outlet. As described above, since the casing base is installed, the airflow collision loss in the air passage can be reduced without increasing the size of the airframe.

  In addition, the L-shaped bending direction of the cross section of the casing base protrudes toward the drain pan, and the L-shaped bending direction of the casing base is on the drain pan side and does not block the casing suction port. It has the effect | action that the collision loss of the airflow in a wind path can be decreased without it.

  Further, the casing base is arranged on the casing side plates on both side surfaces of both suction centrifugal fans, and the L-shaped bending height of the section of the casing base on the casing side plate side to which the motor is fixed is set to the L-shape of the other casing base. It is configured to be larger than the bending height, and the L-shaped bending height and strength of the casing base support the bottom surface of the casing side plate on the heavy side. The L-shaped bending height of the casing base that supports the casing side plate on the other side, which is the other side, can be reduced, and the collision loss of the airflow in the air passage can be reduced without increasing the size of the airframe. Has an effect.

  In addition, a clearance is provided between the casing base and the drain pan for cleaning by inserting a hand, the inspection opening and the fuselage bottom opening communicate with each other, and the casing base and the drain pan are connected from the inspection opening. Since a hand can be inserted between the two, the operation and structure for removing the drain pan are not required, and the inner surface of the drain pan can be easily cleaned.

  Further, the opposite side of the inspection opening of the machine body is configured to fix the drain pan and the machine body so that they can be fitted together, and the other machine body surface is configured to be fixed by screwing the joint between the drain pan and the machine body. Because the drain pan and the fuselage are not screwed on the opposite side of the opening, the screw for joining the drain pan and the fuselage can be removed from the side of the inspection opening. It can be removed and cleaned.

  In addition, a casing sound absorbing material is disposed on the casing side plate, and the casing sound absorbing material is configured to be in contact with and supported by the casing base. Since the casing base has a function of supporting the casing sound absorbing material, a separate member is attached. Without being peeled off, the casing sound-absorbing material is prevented from being attached by the airflow from the airframe inlet.

  Also, the airframe sound absorbing material is arranged on the inner surface of the airframe, and the airframe sound absorbing material is configured to support the airframe sound absorbing material in contact with the casing base, and the casing base has a function of supporting the airframe sound absorbing material. It has the effect | action that the peeling of the body sound-absorbing material by the airflow of a casing suction port can be prevented and it can attach without attaching.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
As shown in FIGS. 1 and 2, the airframe inlet 1 and the airframe outlet 2 are provided on opposite side surfaces of the box-shaped airframe 3. The airframe 3 is provided with a suction adapter 5 that connects the suction side duct 4 to the airframe suction port 1, and the airframe outlet 2 is provided with a blowout adapter 7 that connects the blowout side duct 6. Inside the airframe 3, there is an air path 8 from the airframe inlet 1 to the airframe outlet 2, and the air inlet 8 is provided with a double suction centrifugal blower 9. Both suction type centrifugal blowers 9 are provided with a discharge port 10 facing the fuselage outlet 2, a casing side plate 13 provided with a spiral scroll 11 and a casing suction port 12 on both sides, and both suction type impellers 14 are connected to the casing suction port. It is driven by a motor 15 fixed in the vicinity of 12. One surface of the airframe 3 facing the casing suction port 12 is provided with an inspection opening 16, and an airframe bottom opening portion 17 opened with the one surface of the airframe 3 not facing the casing suction port 12 as a bottom surface. A drain pan 18 is connected to the machine body bottom opening 17, and a casing base 19 that fixes both suction type centrifugal fans 9 to the machine body 3 is fixed to the bottom surface of the casing side plate 13, and the casing base 19 faces the machine body 3. It is set as the structure which connects an inner surface. The drain pan 18 and the casing base 19 are arranged with a distance so that the airflow passes under the casing base 19 (between the drain pan 18). The space below the casing base 19 serves as a passage path for airflow toward the casing suction port 12 as the casing base lower surface air passage 20.

  The casing base 19 has an L-shaped cross section (L-shaped bend 25), and is arranged to protrude toward the drain pan 18 (downward). Further, the casing base 19 is arranged in a direction from the airframe inlet 1 toward the airframe outlet 2.

  Further, as shown in FIG. 3, the airframe 3 is constructed by connecting the suction side duct 4 to the airframe suction port 1 and the airflow side duct 6 to the airframe outlet 2 in the ceiling 26, and the airframe 3 is connected to the airframe on the suction side. The suction inlet 1, the air blower outlet 2 on the blowout side, and the both suction centrifugal blowers 9 are arranged inside the airframe 3. When the both suction type centrifugal blowers 9 are operated, the air in the room 27 passes through the blowout side duct 6 via the suction side duct 4 and the both suction type centrifugal blowers 9 and is exhausted to the outside 28. The ceiling 26 and the room 27 are partitioned by a ceiling material 29, and a ceiling inspection port 30 is provided in the lower part of the body 3 of the ceiling material 29.

  With the above configuration, since the drain pan 18 serves as a drain receiving portion and an air passage, the air passage area in the airframe 3 can be increased without increasing the airframe 3, and the collision loss of the airflow can be reduced. Since the bottom surface of the side plate 13 is supported, the heavy suction centrifugal fan 9 can be firmly connected to the airframe 3, and the inspection opening 16 and the airframe bottom opening 17 communicate with each other, so that the drain pan 18 is removed. No work is required, and the inner surface of the drain pan 18 can be easily confirmed from the inspection opening 16.

  Further, the airflow direction of the casing base lower surface air passage 20 that has passed through the drain pan 18 becomes a tongue direction airflow 22 that is inclined toward the suction center of the both suction type impellers 14 of the both suction type centrifugal fans 9. Since the air flows in substantially parallel to the inlet direction 24 of the blade 23 of the suction type impeller 14, the wind speed at the blade inlet increases, pressure conversion is easily performed, and the static pressure can be increased. In general, the vicinity of the tongue 21 in the scroll 11 has a small cross-sectional area, so that the static pressure increase rate at the impeller is low, and since this configuration acts near the tongue 21, It is effective against pressure increase.

  Moreover, since the L-shaped bend 25 is provided in the casing base 19 and the strength of the casing base 19 itself is improved, both the suction type centrifugal blowers 9 can be firmly connected to the body 3.

  In addition, since the casing base 19 is installed so that the L-shaped bend 25 of the casing base 19 is oriented along the airflow direction in the airframe from the airframe inlet 1 toward the airframe outlet 2, the airflow can be increased without increasing the airframe 3. The collision loss of the airflow in the road 8 can be reduced.

  Moreover, since the L-shaped bending 25 direction of the casing base 19 is on the drain pan 18 side and does not block the casing suction port 12, the collision loss of the airflow in the air passage 8 can be reduced without increasing the size of the airframe 3.

  As described above, according to the blower with the sound deadening box according to the first embodiment of the present invention, the airframe can be thinned while reducing the pressure loss in the air passage to secure the air volume, the static pressure can be improved, and the strength is improved. And maintainability can be improved.

  Moreover, since the pressure loss in the air passage 8 is reduced, the both suction impellers 14 can be made smaller, and the airframe 3 can be made thinner by downsizing the both suction centrifugal blowers 9, so that the height of the ceiling 26 is increased. It is possible to secure a wide space for the living space of the room 27 by lowering, and it is not necessary to remove the drain pan 18 when taking out the double-suction centrifugal blower 9 during maintenance, and it is further horizontal from the opening 16 for inspection. Since the work can be performed by visually confirming the direction, it is needless to say that the workability can be easily improved even if the ceiling inspection port 30 is small, thereby improving the maintenance.

(Embodiment 2)
As shown in FIG. 4, the casing base 19 is arranged on the casing side plates 13 on both side surfaces of the double suction centrifugal blower 9. Of these two casing bases 19, for the casing base 19 on the casing side plate 13 side to which the motor 15 is fixed, the dimension A of the L-shaped bending height 31 of the cross section is set to the L-shaped bending height 32 of the other casing base 19. The size B is increased. That is, A> B.

  In addition, a space distance 35 for cleaning by inserting a hand 34 between the casing base 19 and the drain pan 18 through the inspection opening 16 after the inspection plate 33 is removed is provided.

  With the above configuration, the casing base 19 having a large L-shaped bending height 31 and a strong strength supports the bottom surface of the casing side plate 13 on the heavy side because of the motor 15, so that the double suction centrifugal fan 9 is firmly attached to the body 3. The L-shaped bending height 32 of the casing base 19 that supports the casing side plate 13 on the other side, which is the other side, can be reduced. Therefore, the collision loss of the airflow in the air passage can be reduced without increasing the size of the airframe 3. Less.

  In addition, since the inspection opening 16 and the fuselage bottom opening 17 communicate with each other, and a hand 34 can be inserted between the casing base 19 and the drain pan 18 from the inspection opening 16, no work or structure for removing the drain pan 18 is required. The inner surface of the drain pan 18 can be easily cleaned.

  As described above, according to the blower with a sound deadening box according to the second embodiment of the present invention, the airframe can be reduced in thickness while reducing the pressure loss in the air passage and ensuring the air volume, and the strength can be improved. And maintainability can be improved.

(Embodiment 3)
As shown in FIG. 5, the drain pan 18 and the machine body 3 are fixed to each other by the insertion member 37 on the opposite side 36 of the inspection opening of the machine body 3, and the other surfaces of the machine body 3 are joined to the drain pan 18 and the machine body 3. Is fixed with screws 38.

  With the above configuration, the side of the inspection opening facing the side 36 is not fixed to the drain pan 18 and the screw 3 38 of the machine body 3, and the drain pan 18 from the inspection opening 16 side through the ceiling inspection port 30 provided in the ceiling material 29. Since the screw for joining the machine body 3 can be removed, the operation of turning around the machine body 3 is not necessary, and the drain pan 18 can be easily removed and cleaned. In the present embodiment, the inner surface of the drain pan 18 can be normally cleaned from the inspection opening 16, but the structure responds to the demand when the drain pan 18 is removed and cleaned due to a large amount of dirt such as oil during ventilation in a kitchen environment. It is.

  Thus, according to the air blower with a sound deadening box of Embodiment 3 of this invention, it can be set as a simple structure and can improve maintainability.

(Embodiment 4)
As shown in FIG. 6, a casing sound absorbing material 39 is disposed on the casing side plate 13, and the casing sound absorbing material 39 is in contact with and supported by the casing base 19.

  With the above configuration, since the casing base 19 has a function of supporting the casing sound absorbing material 39, it is possible to prevent the casing sound absorbing material 39 from being peeled off due to the airflow from the airframe suction port 1 without attaching a separate member.

  Thus, according to the air blower with a sound deadening box of Embodiment 4 of this invention, it can be set as a simple structure and can also reduce noise.

(Embodiment 5)
As shown in FIG. 7, the airframe sound absorbing material 40 is disposed on the inner surface of the airframe 3, and the airframe sound absorbing material 40 is in contact with and supported by the casing base 19.

  With the above configuration, since the casing base 19 has a function of supporting the airframe sound absorbing material 40, it is possible to prevent the airframe sound absorbing material 40 from being peeled off due to the airflow of the casing suction port 12 without attaching another member.

  As described above, according to the blower with a sound deadening box according to the fifth embodiment of the present invention, a simple structure can be achieved and noise can be reduced.

  In addition to the purpose of air transportation such as ventilation blower, air conditioner, dehumidifier, humidifier, air purifier, etc., the equipment can be cooled by using the air blown from the air outlet, and the pressure loss is reduced and the air volume is secured. Therefore, the cooling effect is high, and the present invention can be applied to the use of blowing air for equipment that can be installed compactly.

Side structure diagram of fan with silencer box according to Embodiment 1 of the present invention Front view of the fan with the sound deadening box Side structure diagram showing the installation state of the blower with the sound deadening box Front view of a blower with a sound deadening box according to Embodiment 2 of the present invention Front configuration diagram of a fan with a sound deadening box according to a third embodiment of the present invention Side structure diagram of fan with silencer box according to embodiment 4 of the present invention Front configuration diagram of a fan with a sound deadening box according to a fifth embodiment of the present invention Side view of a conventional fan with a sound deadening box Side structure diagram showing the installation state of the blower with the sound deadening box

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airframe inlet 2 Airframe outlet 3 Airframe 9 Both suction type centrifugal blower 10 Discharge port 11 Scroll 12 Casing inlet 13 Casing side plate 14 Both suction type impeller 15 Motor 16 Inspection opening 17 Body bottom opening 18 Drain pan 19 Casing Base 20 Casing base lower surface air path 22 Tongue direction air flow 25 L-shaped bending 31 L-shaped bending height 32 L-shaped bending height 34 Hand 35 Spatial distance 36 Face to face of inspection opening 38 Screwing 39 Casing sound absorbing material 40 Airframe sound absorption Material

Claims (10)

Inside the box-shaped airframe provided with the airframe suction port and the airframe outlet facing each other, both suction type centrifugal fans are provided, and the both suction type centrifugal blowers are provided with a discharge port facing the airframe outlet and a spiral scroll. A casing side plate provided with a casing suction port is provided on both side surfaces, and both suction type impellers are driven by a motor fixed in the vicinity of the casing suction port, and an inspection opening is provided on one surface of the machine body facing the casing suction port. A blower with a muffler box having a machine body bottom opening that opens with one side of the machine body not facing the casing suction port as a bottom surface, and having a drain pan connected to the machine body bottom opening, the double suction centrifugal fan A casing base that is fixed to the airframe is fixed to the bottom surface of the casing side plate, and the casing base is configured to connect opposite inner surfaces of the airframe. Fan of the butterfly. The air flow from the air suction port is provided with a casing base lower surface air passage that passes through the drain pan and passes through the lower surface of the casing base and then goes to the double suction centrifugal blower, and the suction center of the double suction impeller of the double suction centrifugal blower. The blower with a muffler box according to claim 1, wherein the blower with a sound deadening box is configured to flow into the casing suction port as a tongue direction airflow having an angle inclined toward the front. The blower with a sound deadening box according to claim 1 or 2, wherein the casing base has an L-shaped bent cross section. The blower with a sound deadening box according to claim 3, wherein the casing base is arranged in a direction from the airframe inlet to the airframe outlet. The blower with a muffler box according to claim 4, wherein the L-shaped bending direction of the cross section of the casing base protrudes toward the drain pan. The casing base is disposed on the casing side plates on both sides of the double suction centrifugal blower, and the L-shaped bending height of the section of the casing base on the casing side plate side to which the motor is fixed is set to the L-shaped bending height of the other casing base. 6. A fan with a sound deadening box according to claim 5, wherein the blower is configured to be larger than the above. The blower with a muffler box according to any one of claims 1 to 6, wherein a spatial distance for cleaning by inserting a hand between the casing base and the drain pan is provided. The opposite side of the inspection opening of the airframe is configured to fix the drain pan and the airframe so that they can be fitted together, and the other surface of the airframe is configured to fix the drain pan and the airframe with screws. The air blower with a sound deadening box in any one of 1-7. The blower with a sound deadening box according to any one of claims 1 to 8, wherein a casing sound absorbing material is disposed on a casing side plate, and the casing sound absorbing material is supported in contact with a casing base. The air blower with a sound deadening box according to any one of claims 1 to 9, wherein a sound absorbing material is disposed on an inner surface of the airframe, and the sound absorbing material is supported in contact with a casing base.

Images