JP2013019369A - Blower with silencing box - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blower with a silencing box capable or reducing power consumption with a method at low cost.SOLUTION: A double suction type centrifugal blower 9 is provided in a box shape machine body 3. The air passage 8 blows in two casing suction ports 14 provided on both sides of the double suction type centrifugal blower 9 to divert two split flows by a flow separating plate 18 disposed between a machine suction port 1 and a scroll 13 of the double suction type centrifugal blower 9 opposing the machine suction port 1. Consequently, the air passage can be diverted with a method at low cost and an air passage pressure loss can be reduced by the split flow to achieve low power consumption.

Description

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

  Conventionally, to reduce power consumption by reducing the load on the motor of a fan with a sound deadening box, a shunt silencer is provided on the back of the fan casing of the double suction fan built in the sound deadening box to reduce the airway pressure loss, and the motor The thing which reduced the load of is known. (For example, refer to Patent Document 1).

  Hereinafter, the reduction of the suction noise of the blower with the silencing box will be described with reference to FIG.

  As shown in FIG. 8, a conventional blower with a sound deadening box includes a fan casing 103 in which an impeller 102 is housed in a main body 101 and a double suction centrifugal fan 105 in which a motor 104 is disposed. When the impeller 102 is rotated, air is sucked from the airframe suction port 106 provided in the main body airframe 101 and blown out from the airframe outlet 107 via the both suction type centrifugal blowers 105. A shunt silencer 108 is attached to the back of the fan casing 103, and the air sucked from the airframe suction port 106 is shunted to the motor side air passage 109 and the counter motor side air passage 110 by the shunt silence member 108. The shunt silencer 108 has a substantially triangular prism shape with a sharpened tip, and is designed to reduce the airway pressure loss when the suction airflow collides with the shunt silencer 108.

JP-A-9-273788

  In such a conventional fan with a sound deadening box, in order to reduce the load on the motor, a substantially triangular prism-shaped shunt member is necessary, and the shape of the shunt silencer member is irregular, which increases the material cost. Challenges arise. In addition, since a large air volume type blower with a sound deadening box has a large amount of air to be handled, the wind speed of the suction airflow is increased, and the turbulence of the airflow that collides with the shunt silencer member may increase. In this case, in order to smoothly guide the airflow after the diversion to the suction port of the built-in blower, it is necessary to set the diversion position to some extent away from the built-in blower in order to rectify the airflow. Therefore, the problem that the shunt member becomes large and the material cost becomes high also occurs.

  The present invention solves such a conventional problem, and by devising the structure between the airframe suction port and the back of the casing, even in a large air volume type, the intake air flow can be diverted by an inexpensive method. An object of the present invention is to provide a fan with a sound deadening box that can smoothly guide the airflow to the inlet of the built-in fan and reduce power consumption.

In order to achieve the above object, the blower with a sound deadening box according to the present invention includes a double suction centrifugal blower inside a box-shaped airframe provided with a rectangular airframe inlet and an air outlet facing each other. The centrifugal fan has 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 an impeller is driven by a motor fixed in the vicinity of the casing suction port. A fan with a sound deadening box,
The impeller has a rotation axis orthogonal to the wind direction of the air path from the airframe inlet to the airframe outlet,
Between the airframe inlet and the scroll of the both suction type centrifugal blower, provided with a flow dividing plate so as to face the airframe inlet,
This shunt plate is provided on the two casing suction ports provided on the side where the rotation direction of the impeller is opposite to the wind direction of the air passage, and the air passages are provided on both side surfaces of the both suction centrifugal fans. It is divided into two so as to flow.

  According to the present invention, a double-suction centrifugal blower is provided inside a box-shaped airframe provided with a rectangular airframe suction port and a body air outlet facing each other, and the both suction-type centrifugal blowers face the airframe air outlet. A blower with a muffler box provided on both sides with a casing side plate provided with a discharged outlet, a spiral scroll and a casing suction port, and driven by a motor fixed in the vicinity of the casing suction port, the impeller Has a rotation axis orthogonal to the wind direction of the air path from the airframe inlet to the airframe outlet, and between the airframe inlet and the scroll of the both suction centrifugal blowers, On the other hand, the flow dividing plate is provided on the side where the rotation direction of the impeller is opposite to the wind direction of the air passage, and the air passage is provided on both side surfaces of the both suction centrifugal blowers. Two casings provided By splitting into two so as to flow into the inlet, even in a large air volume type, the intake airflow is diverted by an inexpensive method, and the airflow after the diversion is smoothly guided to the inlet of the built-in blower for low consumption It is possible to provide a blower with a silencing box that has the effect of being able to be powered.

Plane | planar block diagram of the air blower with a silencer box of Embodiment 1 of this invention Side view of the fan with the sound deadening box Side structure diagram showing the installation state of the blower with the sound deadening box The figure which shows the state of the shunt by the blower with the sound deadening box (a) The figure of the area which does not collide with the shunt plate, The (b) The figure of the area which collides with the shunt plate Comparison graph of power consumption due to difference in height and position of shunt plate Plane configuration diagram in which sound-absorbing material is provided on the shunt plate of the blower with the sound deadening box Plane | planar block diagram of the air blower with a silencer box of Embodiment 2 of this invention Plan view of conventional blower with silencer box

A blower with a sound deadening box according to claim 1 of the present invention,
Provided with both suction type centrifugal blower inside the box-shaped airframe provided with the rectangular airframe inlet and airframe outlet facing each other,
This both suction type centrifugal blower is provided on both sides with a casing side plate provided with a discharge port facing the airframe outlet, a spiral scroll and a casing suction port,
A fan with a sound deadening box that drives an impeller by a motor fixed in the vicinity of the casing suction port,
The impeller has a rotation axis orthogonal to the wind direction of the air path from the airframe inlet to the airframe outlet,
Between the airframe inlet and the scroll of the both suction type centrifugal blower, provided with a flow dividing plate so as to face the airframe inlet,
This shunt plate is provided on the two casing suction ports provided on the side where the rotation direction of the impeller is opposite to the wind direction of the air passage, and the air passages are provided on both side surfaces of the both suction centrifugal fans. The flow is divided into two so as to flow, and the flow dividing plate distributes the suction airflow to the motor side air passage and the counter motor side air passage without providing a deformed shape or large volume diversion silencer on the back of the casing. The air path pressure loss can be reduced by the diversion.

  Further, the relationship between the height A of the flow dividing plate and the height B to the center position of the impeller is 3/4 · B ≦ A ≦ B, and the inflow direction and the rotation direction of the suction airflow are the same. In the region above the impeller center of the fan casing where airflow easily flows into the impeller, there is little change in the air volume even when there is no shunt plate, so the height A of the shunt plate and the center position of the impeller By making the relationship with the height B of 3/4 · B ≦ A ≦ B, the height of the flow dividing plate can be lowered.

  The relationship between the distance C between the flow dividing plate and the both suction centrifugal fans and the diameter D of the impeller is 1/2 · D ≦ C ≦ D. By setting the relationship between the distance C and the diameter D of the impeller to 1/2 · D ≦ C ≦ D, the casing internal volume is generally small, so the static pressure increase rate at the impeller is low, and work is difficult. The airflow flowing into the low-pressurized region of the tongue, which is a part, can be quickly diverted in the vicinity of the fuselage inlet, rectified, and then flowed into both suction centrifugal fans. As a result, the air current flows into the impeller even in the low-pressurized region of the tongue, and the fan efficiency can be increased.

  In addition, a sound absorbing material is attached to the air distribution inlet side of the flow dividing plate, and the air flow noise due to the collision of the sucked air flow with the flow dividing plate can be reduced.

  Further, the motor side end and the counter motor side end of the flow dividing plate are bent toward the both suction centrifugal blowers, and the suction airflow colliding with the flow dividing plate is smoothly countered with the motor side air passage. The air can be diverted to the motor side air passage, and airflow noise due to the collision can be reduced and the air passage pressure loss can be reduced.

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

(Embodiment 1)
As shown in FIG. 1 and FIG. 2, the blower with a sound deadening box according to the present embodiment is provided with a body inlet 1 and a body outlet 2 on opposite side surfaces of a box-shaped body 3. The airframe 3 is provided with a suction side angular flange 5 that connects the suction side duct 4 to the airframe suction port 1, and the airframe outlet 2 is provided with a blower side angular flange 7 that connects the blowout side duct 6. Inside the airframe 3 is an air passage 8 extending from the airframe inlet 1 to the airframe outlet 2. A double suction centrifugal blower 9 is disposed in the body 3 (air passage 8). The both suction type centrifugal blower 9 includes a discharge port 10 facing the fuselage outlet 2, an impeller 12 fixed to a motor 11, a spiral scroll 13, and casing side plates 15 on both sides provided with a casing suction port 14. A fan casing 16. A sound absorbing material 17 is disposed on the rear surface of the fan casing 16, and a flow dividing plate 18 for diverting the sucked air flow is disposed between the sound absorbing material 17 and the machine body inlet 1. The shunt plate 18 is provided so that its surface is orthogonal to the wind direction of the air passage 8 so as to face the airframe inlet 1. Further, the flow dividing plate 18 is attached to the inner wall surface of the machine body 3 on the side where the rotational direction of the impeller 12 is opposite to the wind direction of the air passage 8. The shunt plate 18 has two airflows (the motor-side airway 19 and the anti-motor-side airway 20) that direct the airflow in the airway 8 toward the two casing suction ports 14 provided on both side surfaces of the both suction centrifugal fans 9. ).

  As shown in FIG. 3, such a blower with a silencing box is constructed by connecting a suction side duct 4 to the airframe inlet 1 and an outlet side duct 6 to the airframe outlet 2 in the ceiling 22. The airframe 3 is provided with an airframe inlet 1 on the suction side, an airframe outlet 2 on the blowout side, a double suction centrifugal blower 9 inside the airframe 3, and a construction hanging bracket 23 on the outer surface. The airframe 3 is installed on the ceiling 22 by fixing the construction suspension bracket 23 to the suspension bolts 25 embedded in the ceiling surface 24. When the both suction type centrifugal blowers 9 are operated, the air in the room 26 passes through the suction side duct 4 and the blowout side duct 6 via the both suction type centrifugal blowers 9 and is exhausted to the outdoor 27. The ceiling back 22 and the room 26 are partitioned by a ceiling material 28, and the ceiling material 28 is provided with a ceiling inspection port 29 at a position directly below the airframe 3.

  The operation and effect of the above configuration will be described. The airflow generated by the impeller 12 rotated by driving the motors 11 of both suction type centrifugal blowers 9 flows into the airframe 3 from the air intake duct 4 through the airframe suction port 1. The airflow flowing into the inside of the machine body 3 is divided into two hands, a motor-side air passage 19 and an anti-motor-side air passage 20 by the flow dividing plate 18. The separated air currents in the motor-side air passage 19 and the counter-motor-side air passage 20 are directed to the casing suction port 14 while avoiding the scroll 13.

  Here, the most characteristic part of the present embodiment is that the motor-side air passage 19 and the counter-motor-side air passage 20 that are divided flow are such that the rotation direction of the impeller 12 is opposite to the air direction of the air passage 8. It is in a place where it concentrates on the part. That is, the flow dividing plate 18 divides the air on the side where the rotation direction of the impeller 12 is opposite to the wind direction of the air passage 8, and changes the flow direction of the air flowing into the casing suction port 14 of the impeller 12. It will be closer to the direction of rotation. This state is shown in FIG.

  FIG. 4A shows the air flow on the side where the air passage 8 does not collide with the flow dividing plate 18 (the side where the direction of the air passage 8 and the rotation direction of the impeller 12 are the same). In this case, the air passage 8 colliding with the scroll 13 is divided along the fan casing 16 of the both suction type centrifugal blowers 9 and to the two casing suction ports 14 while maintaining the air flow toward the fuselage outlet 2 side. Inflow. That is, the rotation direction of the impeller 12 and the wind direction of the motor side air passage 19a and the anti-motor side air passage 20a coincide with each other and flow smoothly.

  On the other hand, FIG. 4B shows the air flow on the side where the air passage 8 collides with the flow dividing plate 18 (the side where the direction of the air passage 8 and the rotation direction of the impeller 12 are opposite). In this case, the air passage 8 colliding with the flow dividing plate 18 is largely divided into the motor side air passage 19b and the counter motor side air passage 20b toward the inner wall surface of the body 3 before reaching the scroll 13. Then, before the casing suction port 14, the flow direction is changed to the casing suction port 14 side and flows into the casing suction port 14. That is, in the part where the rotation direction of the impeller 12 is directed backward with respect to the air passage 8, the motor side air passage 19b and the non-motor side air passage 20b flowing into the casing suction port 14 are air velocities toward the airframe outlet 2 side. The vector becomes small and smoothly flows into the casing suction port 14 without countering the rotational direction of the impeller 12.

  Here, as shown in FIG. 2, the distance between the inner wall surface (reference inner wall surface S) of the airframe 3 on the side where the rotation direction of the impeller 12 is opposite to the wind direction of the air passage 8 and the rotation axis of the impeller 12. Is impeller height B. The height of the flow dividing plate 18 (the height from the reference inner wall surface S to the top) is defined as the flow dividing plate height A. The flow dividing plate height A and the impeller height B are set to have a relationship of approximately 3/4 · B ≦ A ≦ B.

  By setting the diverter plate height A in this way, the airflow diverted by the diverter plate 18 flows smoothly in the rotational direction of the impeller 12. That is, the above-mentioned effect is efficiently shown by diverting in the vicinity of the same height as the rotating shaft of the impeller 12.

  Similarly, as shown in FIG. 2, the distance C between the flow dividing plate 18 and the both suction type centrifugal blowers 9 is preferably set to 1/2 · D ≦ C ≦ D in relation to the diameter D of the impeller 12.

  Generally, since the internal volume of the casing is small, the static pressure increase rate at the impeller 12 is low in the vicinity of the tongue (tongue low pressurization region 21), and the work is difficult to work. The airflow flowing into the tongue low pressure increasing region 21 is diverted early in the vicinity of the airframe suction port 1, rectified, and then flowed into the both suction centrifugal blowers 9, so that the impeller 12 also in the tongue low pressure increasing region 21. The airflow will flow into and work. Therefore, the position to be diverted was calculated as described above as a ratio with the diameter of the impeller 12 determined in proportion to the air volume and the wind speed.

  FIG. 5 shows a comparison graph of current consumption according to the difference in height and position of the flow dividing plate 18 in the present embodiment. As shown in FIG. 5, the power consumption tends to decrease as the height A of the flow dividing plate 18 is increased, but it can be confirmed that there is no change at 3/4 · B or more. Further, regarding the distance C between the flow dividing plate 18 and the both suction type centrifugal blowers 9, the power consumption tends to decrease as the distance increases, but it can be confirmed that there is no change at 1/2 · D or more.

  As described above, according to the blower with a sound deadening box according to Embodiment 1 of the present invention, it is possible to reduce the cost of the product even in the large air volume type connected to the square duct, and to reduce the airway pressure loss and the double suction centrifugal fan. By increasing the fan efficiency, the motor load can be reduced and the power consumption can be reduced.

  In FIG. 6, the thing which affixed the sound-absorbing material 30 to the machine body inlet side of the flow dividing plate 18 is shown.

  By attaching the sound absorbing material 30 to the flow dividing plate 18, the flow dividing plate 18 itself can also have a sound absorbing effect, and air flow noise due to the collision of the sucked air flow with the flow dividing plate 18 can be reduced.

(Embodiment 2)
In FIG. 7, the motor-side end 31 and the counter-motor-side end 32 of the flow dividing plate 18 are bent toward the both suction centrifugal blowers 9.

  The operation and effect of the above configuration will be described. As described in the first embodiment, the airflow generated by the impeller 12 that is driven and rotated by the motor 11 of the double suction centrifugal blower 9 passes through the airframe suction port 1 from the suction side duct 4 to the inside of the airframe 3. Flow into. The airflow that has flowed into the body 3 is divided into a motor-side air passage 19 and a counter-motor-side air passage 20 by the flow-dividing plate 18 and flows into the both suction centrifugal blowers 9. In the present embodiment, the motor-side end 31 and the non-motor-side end 32 bent toward the both-suction centrifugal blower 9 side cause the airflow that collides with the flow dividing plate 18 to be smoothly diverted to the left and right. The airflow can be guided to the blower 9.

  Thus, according to the blower with a silencing box according to the second embodiment of the present invention, airflow noise due to a collision can be reduced, so that the suction noise of the airframe can be reduced. Further, since the airway pressure loss can be reduced, the power consumption can be reduced.

  In addition to the purpose of air conveyance such as ventilation blower equipment, the present invention can also be applied to the use of air blowing of equipment equipment that can cool equipment equipment using air blown from the air outlet.

DESCRIPTION OF SYMBOLS 1 Airframe inlet 2 Airframe outlet 3 Airframe 8 Air path 9 Both suction type centrifugal blower 10 Discharge port 11 Motor 12 Impeller 13 Scroll 14 Casing inlet 15 Casing side plate 16 Fan casing 17 Sound absorbing material 18 Diverging plate 19 Motor side air passage 20 Anti-motor-side air passage 23 Construction hanging bracket

Claims (5)

A box-shaped airframe provided with a rectangular airframe suction port and airframe air outlet facing each other is provided with a double suction centrifugal blower, and the both air suction centrifugal blower has a discharge port and a spiral shape facing the airframe air outlet A blower with a sound deadening box equipped with a casing side plate provided with a scroll and a casing suction port on both sides, and driven by a motor fixed to the vicinity of the casing suction port,
The impeller has a rotation axis orthogonal to the wind direction of the air path from the airframe inlet to the airframe outlet,
Between the airframe inlet and the scroll of the both suction type centrifugal blower, provided with a flow dividing plate so as to face the airframe inlet,
The shunt plate has two casings provided on the inner wall surface on the side where the rotation direction of the impeller is opposite to the wind direction of the air passage, and the air passages are provided on both side surfaces of the both suction centrifugal blowers. A fan with a sound deadening box that diverts into two so as to flow into the suction port. In the flow dividing plate, the relationship between the height A from the attached inner wall surface and the height B from the inner wall surface to which the flow dividing plate is attached to the center position of the impeller is 3/4 · B ≦ A ≦ B. The blower with a muffler box according to claim 1, wherein 3. The relationship between the distance C between the flow dividing plate and the suction suction centrifugal fans and the diameter D of the impeller is set to 1/2 · D ≦ C ≦ D. 4. Blower with silencer box. The sound-absorbing box-equipped blower according to any one of claims 1 to 3, wherein a sound-absorbing material is attached to the air-suction inlet side of the flow dividing plate. The fan with a sound deadening box according to any one of claims 1 to 4, wherein the motor side end and the counter motor side end of the flow dividing plate are bent toward both suction centrifugal fans.

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