FR2461837A1 - BLOWER HOUSING WITH TRANSVERSAL CURRENT, ESPECIALLY FOR USE AS A ROOF FAN - Google Patents

Abstract

HOUSING FOR A CROSS-CURRENT FAN CONTAINING A STEERING BODY 4 SEPARATING THE INPUT AND OUTPUT CURRENTS, A DEFLECTOR SHEET 5 GUIDING THE OUTPUT CURRENT IN A SPIRAL, AND A BLADE WHEEL 1 BETWEEN THE BODY AND THE SHEET. CRANKCASE CHARACTERIZED BY AN ARRANGEMENT OF THE STEERING BODY 4 AND OF THE DEFLECTOR SHEET 5 SUCH THAT, WITH A FLAT AND HORIZONTAL PRESSURE VOLUME CHARACTERISTIC, A MAXIMUM QUANTITY OF DYNAMIC ENERGY IS CONVERTED INTO STATIC ENERGY AT THE OUTPUT, THE SPORTING CENTER IS REGULATED. NORMAL, PUSHING BACK TO THE INSIDE OF THE WHEEL, AWAY FROM THE AUB CROWN, AND, IN STRANGLE SPEED, THIS CENTER BEING MAINTAINED IN A RADIAL POSITION MOVING ALONG THE INTERNAL FACE OF THE WHEEL IN DIRECTION OPPOSED TO ROTATION. PROVISION APPLICABLE IN PARTICULAR TO USE AS A ROOF FAN.

Description

1 22461837

  The invention relates to a ventilator fan housing

  cross-flow current, intended in particular for the use

  the roof fan, which comprises on the one hand a flow director body which separates the incoming air stream from the outgoing air stream, and, on the other hand,

  a baffle plate, which contains the fan wheel

  between her and the governing body stretching in shape

  spiral and guiding the outgoing air flow.

  The object of the present invention is to provide a ventilation

  of the above type, whose behavior in service is such, and whose characteristic curve of the pressure / volume ratio is such that, with a multi-channel connection, the pressure in the channel system is independent of the number

  connected channels and remains constant, and is also inde-

  the state of strangulation of each individual channel system, so that the operation does not

  that a noise as low as possible.

  For this purpose, the fan according to the invention is characterized in that the deflector plate and the steering body are constituted, arranged, and conjugated in such a way that

  by minimizing and constantly maintaining the dynamic energy

  at the outlet, the fan blower operates next

  a characteristic pressure / volume curve that is flattened and

  horizontally similar to the characteristic curve of a boiler, in that, on the one hand, in normal mode, the swirling center is pushed further inside the wheel and away from the blade crown and is maintained in that position, while, on the other hand, in a strangled regime,

  this center of vortex, seen in a radial direction, remains sensi-

  in the same position by moving along the inner face of the blade ring, in a direction opposite to the direction of rotation of the wheel, in which case, in addition, on the path towards the outlet of the housing, an energy dynamic too

  as much as possible is converted into static energy.

  For this purpose, the governing body is judiciously

  relative to the fan wheel in such a way that it

  same, or its fictitious extension, extends at least for its essential part along the outer side of a side domain

  wheel pressure and shifts to a certain extent

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below or above it.

  The description according to the invention may be such

  that, for example, the radius extending from the center of the wheel to the starting point of the spiral forms, with the radius extending towards the point of the steering body nearest the circumference of the wheel , an angle less than 180

  degrees, preferably between 120 and 160 degrees, in par-

  especially between 130 and 140 degrees. Preferably, it may be provided that the line, passing through the point of the main body farthest from the outlet towards the airflow, perpendicular to the end zone, the outlet side, of the steering body, or the line passing through the point of the main body furthest from the outlet, perpendicular to the center line of the outlet diffuser of the fan casing, or to the central flow axis in the diffuser, has, in relation to the tangent to the periphery of a wheel which is parallel to it, a distance which is between 10 and 30%, preferably between

  12.5 and 18% of the diameter of the impeller.

  It may be advantageous for the spokes starting from

  from the wheel to the two end points of the domain

  of the steering body, which influences the flow in the direct area of the periphery of the wheel, and which separate from each other the portions directly adjacent to the inlet and outlet of the flow, enclose between them a angle between 20

  and 30, preferably between 23 and 250, or that the projection

  tion of the effective area of the governing body influencing the

  in the direct area of the wheel and separating from one another the portions directly adjacent to the flow of

  entry and exit, corresponds to approximately 4 to 7% of the

  around the wheel rim. The steering body may then have, for example, the shape of a drop, whose tip is oriented on the opposite side to the wheel, or also the shape of a drop of constant thickness, or a corner whose side the thickest

  is turned away from the wheel.

  Thanks to the constitution according to the invention of the

  tilator, a flattened characteristic curve is obtained horizontally

  zontal or substantially horizontal which presents, for example

  when used in roof fans, the

  important when connecting to multiple

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  channels, the pressure in the channel system remains constant regardless of the number of channels or equals regardless of

  the state of strangulation of individual or approximate systems

  constantly. During a throttling of the fan, a substantially constant pressure is produced. In all cases,

  the noise behavior of the fan is extremely favorable

  This is an important advantage for use cases where

specializations.

  Advantageously, the output of the blower may consist of a gradually widening channel in the manner of a diffuser. For example, the arrangement may be such that, between the periphery of the rotating wheel on the outlet side and the outlet of the fan casing, a relatively

  small, preferably coiled or curved, which widens slightly

  diffuser shaped towards the outlet.

  The measures provided according to the invention have the advantage that, on the one hand, on the path from the wheel outlet to the fan outlet, as much dynamic energy as possible is converted into static energy. , and, on the other hand, thanks to the constitution and

  at the disposal of the steering body in relation to the wheel

  nant, the swirl core (vortex center) is pushed as far as possible, away from the blade crown, into the interior of the wheel, so that as little as possible of flow lines to great speed

  execute a pulse exchange with the paddle crown. EGA-

  During a throttling, the swirling core which moves in a direction opposite to the direction of rotation of the wheel along the inner face of the blade crown is

  maintained substantially at the same distance from the blade crown.

  In this way, one obtains, on the one hand, that the pressure at any location of the characteristic curve does not become too high, and that, on the other hand, the characteristic curve of

  pressure extends substantially to the same height.

  The following description refers to ways of realizing

  of the invention, given as non-limiting examples, with reference to the accompanying drawings, in which: FIGS. 1 and 2 are a diagrammatic representation of a

  first embodiment of the object of the invention,

  In normal operation and in a throttle mode, FIG. 3 is a variant of the embodiment of FIG. 2. FIG. 4 shows the characteristic pressure / volume curve of the arrangements according to FIGS. 1 to 3.

  Figures 5 to 10 show different variants of

  tion of the object of the invention, each time in schematic side elevation view;

  Figure 11 is a side elevational view of another vault

laughing achievement,

  Figure 12 is a side elevational view of another

  embodiment of the invention, and FIG. 13 shows the pressure / volume characteristic curves

  different fans blowers.

  In the arrangement shown in Figures 1 and 2, it is a cross-flow blower, which is specifically intended for use in connection with roof fans. It comprises a rotating wheel 2 and a housing, a steering body 4 separating the incoming current along the arrow 2 from the outgoing current along the arrow 3, and a deflector plate 5, the rotating wheel 1 being contained between the steering body 4 and the sheet 5, the latter leading to

  outgoing current and extending into a spiral shape.

  In the arrangement according to FIGS. 1 and 2, the sheet

  deflector 5 and the governing body 4 are constituted and

  between them and with respect to the impeller 1, so that by a constant maintenance and a low maintenance of

  the dynamic energy at the fan outlet, this one

  with a flat pressure / volume characteristic curve extending horizontally or substantially horizontally, as shown at 9 in FIG. 4. On the one hand, in a normal regime, the vortex center 10 is pushed further into the interior of the wheel, away from the blade crown, and is no longer very close to the inner circumference of the blades, which means that the flow lines 11, lines 11 of

  extremely high speed no longer cross the wheel or only

  lie on the edges of the latter, this wheel is

  in exchange for pulses with the current lines 12 of lower speed. In the arrangement according to the invention, the vortex core, in normal operation, is maintained in the position shown in FIG. 1, while in steady state with

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  strangely, the vortex center, seen in the radial direction, retains substantially the same position and moves on the inner face of the vane crown, in the opposite direction

in the direction of rotation 13 of the wheel.

  In Figure 2, we see that the center of tourbillon

  is still at approximately the same radial distance from the

  of blades, as in the state of normal regime according to Figure 1, however, moved from its point

  starting point, in the opposite direction to the direction of rotation.

  The arrangement according to the invention is, in addition, such that in addition, on the path to the output of the housing 14, as much as possible of dynamic energy is converted into static energy, as seen for example in Figure 5, the fan outlet 15 consists of a channel

  which widens gradually in the form of diffuser. accordance

  5, between the periphery of the wheel on its outer side at 16, and the fan outlet 15, there is provided a relatively long channel 17, preferably slightly wound or curved, which widens towards the shaped outlet. in which, for example, the dimension h2 is greater than the dimension h1, and the dimension h3 is possibly greater than

the dimension h2.

  In this embodiment, following the output of the fan is mounted a set of guide vanes or plates 18, with which the current is deflected upwardly directed diametrically away from the fan inlet 19. In Figure 4, is visible this behavior of the fan according to the invention. In this figure 9 is the pressure / volume characteristic, a is the working pressure in the normal state, b is the

  in the strangled state, these two states are

  substantially at the same pressure with different volumes.

  In both cases, the static pressure in the installation is constant, despite a change in volume. The displacement of the vortex center in the direction opposite to the direction of rotation in the throttled state means that practically the same flow lines pass through the wheel always with the same speed.

  and the impulse change has remained the same, but that, however,

  However, more power lines come back into the wheel, which means that they transmit exactly as much

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  energy, but that the same amount of energy is no longer trans-

  scope. FIG. 3 again shows the same throttled state as in FIG. 2 but in this case there is further provided a small flow return channel 8 through which the flow from the pressure side is transported towards the wheel. This means, in accordance with Figure 4, that the

  characteristic curve has been moved upwards in the

  20, indicated by a dotted line, because a higher pressure is present, because, by going back, the center of

  swirling was moved again closer to the cou-

dawn.

  In the diagram of FIG. 13 are shown three characteristic curves 21, 22 and 23, which show how the intensity of the return current exerts an influence. The lower curve 21 corresponds to unwinding without a return current, the curve 22 to unwinding with a low return current and the curve 23 to unwinding with a stronger return current. The arrangement according to the invention also has the effect that the noise produced by the fan is much lower, because high speed current lines no longer cross the wheel, the flat characteristic curve being

  symptomatic for a low noise fan.

  In all the examples of FIGS. 5 to 12, it can be seen that the steering body is arranged with respect to the wheel so that its imaginary extension extends, at least over a large part, along the outer side of a domain pressure side of the wheel and is shifted above or below the

  wheel according to the side from which it is considered.

  In the arrangement of Figure 5, the median longitudinal axis or longitudinal axis of symmetry of the steering body 25 is arranged tangentially to the wheel, and, seen from the fan inlet, the body is shifted slightly above

  26. In the arrangement of Figure 6, the outer wall

  27 of the main body 28 on the discharge side is dis-

  placed almost tangentially to the wheel 29. It is the same for the arrangement of Figure 7 while in the other embodiments of the subject of the invention, this wall

  outside of the suction side of the steering body extends

gentially to the wheel.

  All of these measures contribute to the vortex center being displaced slightly radially inwardly from the blade crown as described above.

  It is also seen in Figure 6 that in the provision

  According to the invention, the radius from the center 30 or 31 of the wheel towards the start point 32 or 33 of the spiral (radius designated respectively 34 and 35) forms, with the radius 36 or 37 going to the point 38 or 39 of the steering body 28 or closest to the periphery of the impeller, an angle O1 or 3L2 of less than 1800, preferably between 120 and

  1600, in particular between 130 and 1400. With such a positioning

  From the point of the steering body closest to the periphery of the impeller, the vortex center is again forced back into the inside of the wheel away from the wheel.

crown of blades.

  The effect sought with the invention is also still achieved by the other measure consisting in that, as in the

  examples of figures 6 and 8 to 11, the perpendicular 50-51-52-

  53-54 passing through the point 45-46-47-48-49 of the steering body furthest from the fan outlet, seen in the direction of

  the flow, towards the end domain, on the outlet side 55-56-57-

  58-59 of the deflector plate, is away from tangents

  60-61-62-63-64-65 around the wheel, which are parallel to it

  from a distance which corresponds to approximately 10 to 30% of

  preferably 12.5 to 18% of the diameter of the wheel.

  In the variant of FIG. 7, the perpendicular that passes through the point 61 of the steering body, the farthest from

  the outlet of the fan, seen in the direction of the flow, allows

  pendicular to the median current line 62 of the output diffuser, or its median axis, has a distance to the tangent, which is also in this case about 10 to 30%, of

  preferably 2.5 to 18% of the diameter of the wheel. These measures serve

  it is also necessary to position and orient the steering body in such a way that the vortex core, on the one hand, is pushed towards the center of the wheel, and on the other hand, in a throttling mode, is caused to move along the inside of the paddle wheel in the opposite direction to the direction

8 2461837

  of rotation, in which case the radial position of the

Billon is substantially maintained.

  Other measures to achieve this goal consist in that the radius going towards the starting point of the spiral, forms, with the median axis of the governing body, an angle understood

  between 75 and 1100. This repression of distance from the nucleus

  swirling center of the inner side of the blade crown is still achieved by the fact that the "shadow" projected by the steering body on the periphery of the wheel is enough

  large to cover about 1/15 to 1/20 around the wheel.

  Advantageously, the projection of the effective domain 70 influences

  the flow in the immediate area around the perimeter of the

  wheel (Figure 6), which separates the immediate parts

  The inlet (arrow 71) and outlet (arrow 72) of the flow are approximately equal to 4 to 7% of the length of the periphery of the wheel. Advantageously, the spokes going from the center of the wheel towards the two end points of the efficiency range of the steering body, which influences the current in the immediate area of the wheel periphery by separating the input and output parts of the current. , form between them

  an angle of about 20 to 30, preferably 23 to 25.

  In the variants according to Figures 7, 8, 9 and 11, the director body has the shape of a drop whose tip moves away from the wheel. In the variants of Figures 6 and 10, the director body has the shape of a drop of uniform thickness. In the variant of Figure 12, the steering body 70 has the shape of a wedge whose thickest side 71 is directed towards the periphery of the wheel. In this case, the median axis of the corner oriented with its thickest part towards the circumference of the wheel forms, with the vertical plane 73 containing the axis of rotation of the wheel (which is substantially perpendicular to the median plane of the exit of the wheel).

  fan) an angle between 25 and 50.

  In the variants of FIGS. 7, 9, 10, 11 and 12, the

  steering body is hollow, and its wall portion, on the opposite side,

  which connects to the wheel side wall facing the fan outlet, is provided with at least one opening

  -81-82-83-84 through which part of the air that flows through

  towards the fan outlet, backs up from the discharge side of the air and enters the interior of the

  hollow body in order to pass through the tower wall portion

  born to the wheel, in the slot between the wheel and the

  Governing Body at 85-86-87-88 and 89.

  In the arrangement of Figure 10, the wall portion of the side of the wheel or at least the part which is closest to the wheel consists of a perforated plate 19. In the provisions of Figures 7-10 and 11 ce; wall portion

  of the main body, on the discharge side, consists of a metal sheet

  drilled 91-92-93. The arrangement could also be such that the wall portion in question of the director body is provided with a through opening, assigned to the range of the outlet out of the discharge duct of the fan and whose

  section is modifiable, being controlled by a flap or obturator

adjustable controller.

  This wall portion, on the discharge side, of the di-

  rector may be, for example, provided with several openings - crossing, which can be closed at least partially, or

  be made of a perforated sheet with a coating member

  for example, a pivoting flap, or a displaceable slide,

  by which the passage of the transported air can be

totally or partially.

  In the arrangement of Figure 6, as in that of

  FIG. 10, the wall portion on the discharge side of the di-

  rector extends substantially parallel to the baffle plate

  who is in front of her. In Figure 11, the main body

  95 has the shape of a triangle whose side facing the wheel

  96 is rectilinear and forms with the periphery of the wheel a slot

  98, which narrows in the direction of rotation 99 of the wheel and which can, for example 88, extend thereafter

  parallel to the circumference of the wheel.

  The current feedback channel can be, as repre-

  felt in the figures, of constant section. But it can also (Figure 12) narrowing towards the wheel (channel 100). The median line of current flowing through this channel extends, in most of the examples shown, tangentially to the periphery of the wheel, and in some examples, radially relative to

at this circumference.

Claims (17)

- R E V E N D I C AT IO N S -   1. Cross-flow fan housing, in particular for use as a roof fan containing a director body (4) separating the input and output currents from one another, and a deflector plate (5), containing between it and the governing body the   impeller (1), guiding the output current and extending   spiral casing, characterized in that the deflector plate   trice (5) and the director body (4) are constituted, arranged, and conjugated, such that, with a reduced and constant maintenance of the dynamic energy at the output of the fan, it operates with a characteristic pressure curve / flat and substantially horizontal volume, by the fact that,   on the one hand, under normal conditions, the vorticity center is   pushed further into the inside of the wheel, away from the   of the blade and is maintained in this position, while, on the other hand, in a choke mode, the vortex center is held in radial position, but moves along the inside of the wheel, in the direction opposite to the rotation,   in which case a maximum amount of dynamic energy is converted   in static energy, in the path towards the exit of the crankcase. 2. Carter according to claim 1, characterized in that the director body is arranged relative to the impeller in such a way that it itself, or its imaginary extension, extends over at least a large part of the outer face   a field on the pressure side of the wheel and runs above it.   3. Carter according to claim 2, characterized in that   that the median longitudinal axis or axis of symmetry of the di-   rector extends tangentially or substantially tangentially at the turning wheel.   4. Carter according to claim 2, characterized in that the outer wall of the discharge side of the steering body extends tangentially or substantially tangentially to the wheel. 5. Carter according to claim 2, characterized in that the outer wall, on the suction side, of the steering body extends tangentially or substantially tangentially to the wheel 2461837.   6. Carter according to any one of the claims   2 to 5, characterized in that the radius extending from the center of the wheel to the starting point of the spiral, forms, with the radius towards the point of the steering body located closest to the wheel, an angle less than 1800 preferably 120 to 1600,   in particular between 130 and 1400.   7. Carter according to any one of the claims   1 to 6, characterized in that the perpendicular to the field of ex-   the tremité exit side of the deflector plate which passes through the   point of the governing body farthest from the exit of the   in the direction of flow, is at a distance from   tangent to the wheel circumference, which is parallel to it, which cor-   about 10 to 30%, preferably 12.5 to 18% of the diameter of the wheel.   8. Carter according to any one of the claims   1 to 7, characterized in that the perpendicular to the central axis of the outlet diffuser or the median line of the current in this diffuser, which passes through the point of the steering body which is farthest from the outlet, is at a distance from distance from the tangent to the periphery of the wheel which is parallel to it, which corresponds to 10 to   0%, preferably 12.5 to 18% of the diameter of the wheel.   9. Carter according to any one of the claims   1 to 8, characterized in that the radius corresponding to the start point of the spiral forms with the median axis of the steering body, an angle between 75 and 1100.   10. Carter according to any one of the claims   1 to 9, characterized in that the shadow projected by the di-   rector on the wheel is important and corresponds to about 1/15 at 1/20 of the circumference of the wheel.   11. Carter according to any one of the claims   1 to 10, characterized in that the projection of the effective domain   of the governing body, separating the parts   of the flow, which influences the flow in the direct area around the wheel, corresponds to a   proportion of 4 to 7% of the length of the circumference of the wheel.   12. Carter according to any one of the claims   1 to 10, characterized in that the radii extending from the center of the wheel to each of the end points of the effective domain 12 2461837   of the steering body which influences the flow in the direct range of the periphery of the wheel to separate the incoming portion and the outgoing portion of the current, form between them an angle   from 20 to 30, preferably from 23 to 250.   13. Carter according to any one of the claims   at 12, characterized in that the director body is in the form of a drop of constant thickness whose tip is diriae the opposite of the impeller.   14. Carter according to any one of the claims   10 to 13, characterized in that the steering body has the form   corner whose thickest side is oriented towards the turn of the wheel.   15. Carter according to claim 14, characterized in that the central axis of the wedge (71), directed with its thickest side towards the periphery of the wheel, forms with the vertical plane   (73) containing the axis of the wheel at an angle of 25 to 50.   16. Carter according to any one of the claims   1 to 15, characterized in that the director body is hollow and the discharge side wall portion which connects to the wheel side wall portion towards the fan outlet has at least one opening through which a portion of the flowing air can revert back from the discharge side into the hollow space of the steering body and enter the slot between wheel and steering body through the wheel side wall of the body, so, for example, that the line median flow of current flowing through the return channel   back can extend radially around the wheel.   17. Carter according to any one of the claims   1 to 12, characterized in that the steering body is in the form of a triangle whose side facing the wheel is rectilinear and forms, with the periphery of the wheel, a slot which narrows at least partially in the direction of rotation of the wheel. the wheel and can   then extend parallel to the circumference of the wheel.