US3282032A

US3282032A - Rotating eliminator

Info

Publication number: US3282032A
Application number: US351418A
Authority: US
Inventors: Jr James F King; Company Wachovia Bank An Trust
Original assignee: Bahnson Co
Current assignee: FLAKTAIR Inc
Priority date: 1962-01-29
Filing date: 1964-03-12
Publication date: 1966-11-01
Anticipated expiration: 1983-11-01

Description

8 Sheets-Sheet 1 S R o T N E v k F s J. F. KING, JR., ET AL ROTATING ELIMINATOR Nov. 1, 1966 Filed March 12, 1964 1966 J. F. KING, JR, ET AL 3,282,032

ROTATING ELIMINATOR Filed March 12, 1964 8 Sheets-Sheet 2 INVENTOR 5 James F. King Jr. Agnew HBwhnson Jr U /MW IJMZW 19 Pm ATTORNEY S Nov. 1, 1966 J. F KING, JR, ET AL 3,282,032

ROTATI NG ELIMINATOR 8 Sheets-Sheet 5 Filed March 12, 1964 James F K/ng J Agnew H. BaJwnson J 1 Pwpw ATTORNEY s N V- 1966 J. F. KING, JR, ET AL 3,282,032

ROTATING ELIMINATOR 8 Sheets-Sheet 4 m J m 0 H M m JJ. R W rm m m mvwm B WM W N 06% H m 5i. i S r Lm #H 8 Q .1 4 6 Q 0 J BY 9 AW Filed March 12, 1964 Nov. 1, 1966 Filed March 12, 1964 J. F. KING, JR., ET AL ROTATING ELIMINA'I'OR 8 Sheets-Sheet 5 FINVENTORS J Kl J A3323; H. Ba lQnsonJr Y Nov. 1, 1966 J. F. KING, JR., ET AL 3,282,032

ROTATING ELIMINATOR Filed March 12, 1964 8 Sheets-Sheet e ulnlm INVENTOR James F KI 1% Agnew H. Bah son Jr BY JZM JJJ Qge-NKQ 1 jW/PA/EV Nov. 1, 1966 J. F. KING, JR, ET AL 3,282,032

ROTATING ELIMINATOR 8 Sheets-Sheet 7 Filed March 12, 1964 INVENTORS James F King Jr- Aghew H. Ba l'lson Jr BY Nov. 1, 1956 J KlNG, JR, ET AL 3,282,032

ROTATING ELIMINATOR Filed March 1.2, 1964 8 Sheets-Sheet 8 INVENTORS James Fkmg Jr. Agnew H.5cwhn5on Jr. BY

United States Patent 3,282,032 ROTATHN ELHMINATOR This invention, which is a continuation-in-part of our copending application Serial No. 264,473 filed March 5, 1963, now abandoned, which in turn was a continuationin-part of our prior application Serial No. 169,432, filed January 29, 1962, and now abandoned, relates to apparatus for treating air for use in air conditioning and air washing systems wherein, for example, the air stream is brought into direct contact with a water spray which serves the dual purpose of washing and removing foreign particles from the air and adding moisture to the air before delivering the same to a particular point of use. In order to remove any water droplets that may become entrained with the air during the washing action, it is customary to interpose an eliminator in the air stream after leaving the washer. These eliminators have, in general, been of the stationary type comprising an assembly of plates with surfaces set at an angle to the direction of air flow through the same so that the airstream is compelled to follow a tortuous path thus separating out the heavier droplets of water as the airstream repeatedly changes its direction of flow through the plate. These stationary eliminators which are known generally as broken plate eliminators have two principal disadvantages, one of which is the comparatively high static pressure loss involved in driving the air through the tortuous paths of the eliminator. Another disadvantage of this type of eliminator is that it becomes clogged within a very short time when used in conjunction with conditioning of air in a textile mill wherein, in addition to dirt, the air contains a large amount of lint liberated during the textile processing operation. This lint becomes entrained in the air which is taken back to the air washer, and a considerable portion of the lint passes through the washer section into the eliminator section where it becomes lodged between the plates. In order to keep the eliminator even reasonably clean, the mill is therefore required to establish a periodic cleaning schedule for the eliminators and they must also carefully screen out the linty material from the return air and, in some cases, from fresh air taken in from the outside.

As an improvement over the stationary types of eliminators others have proposed use of eliminators of the rotary type which include a rotating blade asembly, the blades of which are, for example, V-shaped so as to require the air to undergo a change in direction as it passes through the blade assembly. One such construction is disclosed in US. Patent No. 2,932,360, granted April 12, 1960, in the name of Ernest C. Hungate.

The present invention also relates to an eliminator of the rotating type but is considered to be an improvement over prior developed rotary eliminators in that it operates with a considerably lower pressure loss as compared with the high internal static pressure which characterizes the prior designs.

In general, the rotor element of the eliminator is composed of an assembly of blades which are essentially planar throughout their area and extend outwardly from a rotatable hub to which they are secured. The blades can be located in planes parallel to the axis of rotation of the hub or they can be located in planes at an acute angle to the rotational axis. Air entering channels formed between adjacent straight blades of the improved rotating eliminator will be caused to move in a helical path as it travels ice from one end of the eliminator to the other. The pitch of the helical path taken by the air will be determined by the velocity of the air and by the rotational speed of the eliminator. For example, these two factors combined with a total length through the eliminator may be such that each increment of air entering a channel between adjacent blades of the eliminator will be rotate-d through an angle 60 before exiting. Thus, the rotary displacement of the channel causes any water particle entrained with the air to move by virtue of its own inertia toward the trailing blade of the eliminator. During the time the water laden air is enclosed within the blades of the eliminator, it is being rotated at reasonably high speed and each particle of matter having a mass is propelled by centrifugal force toward the outside of the eliminator. In ad dition to this centrifugal separation of water from the air, there also exists a collateral scrubbing action between the blades which helps to film the water out .upon the surface of the eliminator blades so that it can come up to rotational speed quickly.

The improved rotating eliminator may be positively driven by any suitable means such as an electric motor, or it may be auto-rotated by incorporating a windmill within the housing containing the rotary eliminator, the windmill being located at the air exit end of the eliminator. Moreover, the eliminator assembly may be rotated at a fixed speed or at a variable speed controlled by humidity conditions in a room where the air is to be supplied after leaving the eliminator so as to elfect an accurate control over the amount of moisture removed by the blade action and centrifugal force and thereby obtain a completely controllable wet duct system. On the other hand, the eliminator can be rotated at a speed sufficient to effect removal of all liquid to supply a dry duct system with entrainment free air.

In accordance with another aspect of the invention, the eliminator may be composed of a plurality of eliminator assemblies arranged in cascade along the longitudinal axis of the eliminator. All of the cascaded eliminator assemblies may be mounted for rotation, or the cascaded arrangement may include a stationary eliminator assembly between two adjacent rotating eliminator assemblies to re-direct the air stream between adjacent eliminator assemblies and bring about the most efifective air entrance angle into the downstream eliminator assembly for the purpose of eliminating the entrained water particles. The blades of adjacent eliminator assemblies may also be located in planes at an acute angle to the axis of rotation and in such case the angularly located blades of one eliminator assembly may be located at an angle to the angularly located blades of an adjacent eliminator assembly. Adjacent eliminator assemblies may be rotated in opposite directions to gain some of the advantages inherent in an eliminator of the broken plate type but without entailing any appreciable static losses. Moreover, the various eliminator assemblies may be rotated at progressively increasing speeds in the direction of air flow through the eliminator, so that the slower rotating assemblies at the air inlet and which are burdened with the removal of heavier water droplets, dirt and lint will run without excessive vibration, and the faster rotating assemblies nearer the air exit end of the eliminator will create greater centrifugal forces on the air and any water the eliminator. Adjacent eliminator assemblies may be rotated in opposite directions and at varying speeds to gain the advantages before mentioned. Adjacent eliminator sections may also be rotated in the same direction and at different speeds. A particular advantageous mode of operation of a group of three cascaded sections is one wherein all three sections rotate in the same direction but wherein the center section rotates at a slower speed than two outer sections which latter rotate at the same speed. For example, the two outer sections can rotate at a speed of 130 r.p.m. while the center section rotates at a speed of 34 r.p.m. In addition, each eliminator section may have a different number of blades; preferably the section with the fewest blades upstream of the eliminator and the sections with more blades downstream. Used in this manner, the upstream sections which received the maximum amount of entrained water and dirt which is being washed from the air have less total surface area to contaminate and are more easily cleaned when cleaning becomes necessary and the downstream sections with more blades which are running in a much cleaner atmosphere are capable of removing the smaller water particles from the air. This latter function is possible since eliminating efliciency is, in part, improved when more blades are added to the hub or when the eliminator blades are revolved at a higher rotational speed.

In accordance with another aspect of the invention, arrangements may be made for cleaning off the surfaces of the blades of the eliminator assemblies. This may be accomplished by means of flooding nozzles positioned within the barrel or casing within which the eliminator assemblies are located, the nozzles being located at the end of the eliminator assembly in one or more rows extending from the periphery of the blades to the hub on which they are mounted and serving to direct streams of water longitudinally of the assembly between the blades so as to clean off any particles of dirt, lint, etc., which may have become lodged in the gaps between adjacent blades, and also clean off the surfaces of the blades themselves. The flooding nozzles may also be positioned so as to discharge clean-off water in a generally radial direction onto the blade surfaces from the outer periphery inward toward the hub. The barrel or casing which encloses the eliminator assembly or assemblies if there be more than one can also be conveniently provided with a door extending for the length of the barrel so as to facilitate inspection and cleaning.

While the blades of the improved rotating eliminator assembly are made planar throughout substantially the entire working surface areas thereof, the radially outer surface portions of the blades may be roughened such as by the inclusion of ribs or bumps or the like in order to assist in breaking up the surface tension of the liquid being removed from the air stream so that minute water droplets have a better tendency to coagulate and thereby be more readily acted upon by centrifugal force which is particularly high at the radially outer surface portions of the blades.

The foregoing as well as other objects and advantages inherent in the invention will become more clearly understood from the following detailed description of various embodiments thereof and from the accompanying drawings wherein:

FIG. 1 is a view mostly in central longitudinal section through a complete air washer incorporating the improved rotary eliminator structure and with some parts shown in elevation;

FIG. 2 is a partial vertical section of the rotor structure of the eliminator showing the manner in which the radially inner ends of the planar blades are anchored;

FIG. 3 is a view in perspective of the radially inner edge portion of one of the planar eliminator blades showing the piano hinge construction by which the blades are secured in place;

FIG. 4 is a side elevation of a radially inner portion of one of the eliminator blades;

FIG. 5 is an end view of FIG. 4;

FIG. 6 is also a partial vertical section of the rotor structure showing the particular details by which the rotor blades are anchored to a hub plate;

FIG. 7 is a vertical section taken on line 77 of FIG. 6;

FIG. 8 is also a partial vertical section of the radially outer portions of the blades showing the manner in which the blades are held in spaced relation;

FIG. 9 is a vertical section taken on line 9-9 of FIG.

FIG. 10 is a view in perspective showing the details of construction of the spacer element used in spacing the router portions of the blades from one another;

FIG. 11 is a central longitudinal sectional view throughthe eliminator section of an air washer illustrating a modified construction featuring a plurality of rotatable eliminator assemblies arranged in cascade along the axis of air flow and wherein provision is made for independent rotation of the assemblies;

FIG. 12 is a view 'in development of a portion of the periphery of a modified construction for the eliminator blades wherein the air inlet and air outlet ends of the rotatable blade assembly are curved in opposite directions respectively so as to facilitate the fiow of air into and out of the channels between the blades;

FIG. 13 is a view of an eliminator blade modified to include a surface roughened by ribs for facilitating removal of moisture from the blades;

FIG. 14 is a View of a portion of an assembly of blades in accordance with the construction of FIG. 13.

FIG. 15 is a view of a modified embodiment wherein rotation of the eliminator assembly is effected by means of an adjustable pitch windmill mounted on the shaft which carries the eliminator assembly;

FIG.16 is a section view taken on line 1616 of FIG. 15;

FIG. 17 is a central longitudinal sectional view similar to FIG. 11 but showing a modification which includes means for reverse fiooding of the blade surfaces and the spaces between adjacent blades to wash off any dirt or lint which may have become stuck on the blade surfaces or jammed into the gaps between adjacent blades;

FIG. 18 is a somewhat diagrammatic view showing the embodiment wherein the blades are arranged in planes parallel to the axis of rotation of the bladed eliminator assembly; and

FIG. 19 is a view similar to FIG. 18 illustrating an embodiment wherein the blades are arranged in planes which lie at an acute angle to the axis of rotation of the bladed eliminator assembly.

With reference now to the drawings and to FIG. 1 in particular, the improved high-velocity, low static pressure air washer and eliminator assembly is seen to include an elongated casing 10 through which the air is passed for washing and for thereafter eliminating all or a desired portion of the water droplets which become entrained in the air stream after leaving the washer section of the assembly. The casing 10 thus includes a cylindrical entrance chamber 11 seen at the extreme left in FIG. 1 in which a fan 12 is located, the function of the fan being to force the incoming dirt and lint laden air to be treated through the washer chamber 13 and thereafter through the eliminator chamber 14. A truncated conical section 10b of the casing which diverges in the direction of air flow therethrough is connected to the cylindrical entrance section 10a, and conical section 10b is followed by a cylindrical section 100, the casing sections 1% and 10c serving to establish the washer chamber 13. The cylindrical casing part has a rectangular opening cut into the under portion thereof and a sump 15 is welded to the wall of this opening. A drain pipe 16 is welded to an opening in the bottom wall of this sump so that it can drain away the water which is fed to the washer and which is not evaporated. This drain water is preferably used on a recirculating basis in the washer so that pipe 16 is a gravity drain back to a filter unit 17 to remove foreign particles washed away from the air stream so that the clean water can then be directed from the filter through a pump 18 which returns the water via a pipe 19 to a water inlet header which is constituted by an elongated tube Zll that extends centrally and generally horizontally within the casing sections ltlb, title. The water header tube is closed at the opposite ends thereof by Walls 22 and 23. The diameter of the water header tube 21 at the end wall 22 adjacent fan 12 is preferably the same as the hub portion 12a of the fan blades so that tube 21 not only functions as a header but also serves as an air directing means for the air stream which flows through the washer chamber 13. Water header tube 21 which is pressurized by the water admitted to the same from pump 18 is provided with a plurality of outlet nozzles 24, eight of which are seen in FIG. 1, which are secured directly into the wall of the header tube 21 so that their spray pattern is directed outwardly toward the conical wall section ltib. The number of nozzles can be selected as necessary to establish the required water fiow for the washer and they are preferably located in a helical path around the periphery of the water header so that their spray patterns overlap. In addition, each full circle of nozzles is preferably spaced so that no two nozzles lie along the central axis of header tube 21 but there is a symmetry between the rows of nozzles to achieve a more complete coverage of the area of the Washer which is near the center line.

In addition to the nozzles 24, other nozzles 25 which can be in any appropriate number for the size of the washer, are elevated on header pipes 26' which extend radially outward from header tube 21 to the approximate center line between the transition wall part b and head er tube 21. These nozzles 25 are directed downstream of the air flow to help fill in any gaps which possibly may have been left by the nozzles 24. This 90 overlapping of the water issuing from the individual nozzles assures complete coverage of the washing space within the washer chamber l3'and provides an optimum condition for ob taining a higher saturation efficiency for the unit.

Water header 21 is maintained in its proper position inside of the washer chamber 13 by four struts in the form of plates 27 located 90 apart at the entrance to the conical transition section Nb and by a similar arrangement of four plate-like struts 28 placed at the junction between the washer section 13 and eliminator section 14. These latter struts also serve to support the front bearing 29 for the front end of the rotating eliminator. assembly 3%) which will be described later in further detail.

Washer chamber MD is provided with another water supply header 20 which connects with a separate and continuous water supply located outside the washer casing. This header 26) is mounted rigidly to the lower support 23 to maintain a spaced parallel relation to the tapered front surface of the blades 37 of the eliminator assembly 30, and is provided with a plurality of nozzles 2% which are so positioned as to direct high-velocity low-volume jets of water substantially parallel to the upstream face of the eliminator assembly. Although the nozzles Zita are located on only one header and spray preferably downwardly toward the sump 1'5, each eliminator blade 37 will have its upstream edge scrubbed by the water jets issuing from nozzles Ztla as the blades 37 individually rotate past the water jets. The scrubbing action of the Water jets from nozzles 20a is preferably included on an air washer of the type described if long fiber material such as cotton is being washed from the air flowing through the washer because some of the fibers drape across the edge of the blade, half of their length on one blade side and the other half on the blade opposite side in such a manner as to not be easily removable.

Air Washer saturation efliciency is determined partially by how much water is added to the air stream as it moves through a chamber such as chamber in, and control of such a washer is generally accomplished by throttling the sprays from the primary nozzles such as

plates

33 and 34 respectively.

the nozzles 24, 25. This action reduces the water flushing action on eliminator blades 37 but does not diminish the lint being drawn through the washer to contaminate the eliminator. As a result, the continuous jet sprays from nozzles 2dr: are necessary to remove the lint which is deposited in the eliminator. The more usual procedure is to supply high-volume, low-pressure water from many nozzles facing directly into the eliminator and these are normally termed flooding nozzles. However, it has been found that this procedure allows the saturation efficiency of the washer to drop only to approximately 50% even though the primary nozzles have been closed off. The improved arrangement which has been described featuring the set of nozzles a allows the washer saturation to fall to approximately 20% since a very carefully directed high-pressure, low-volume Water cleaning spray is used.

Since there are no air straightener vanes behind the blades of the fan 12 and the air will be leading at a vector angle relative to the velocity of the air through the washer and the rotational speed of the fan, struts 27 are preferably slanted relative to the longitudinal axis of the washer chamber 13 so that they will not interfere with this discharge helix angle since the air swirl tends to centrifuge the washer water out towards the walls 10b, 100 of the Washer chamber and thereby eliminate much of the water which could possibly have to be eliminated in the straight bladed, rotating eliminator assembly 30. The other struts 28 could also be slanted in the same manner as struts 27 but since the former are so close to the rotating eliminator assembly 39 and because of some practical difficulty in slanting these larger plate members, they are installed parallel with the longitudinal axis of the Washer.

The rotating eliminator assembly 30 is mounted for rotation on shaft 31 which is supported near each end by ball bearing assemblies 29, 32 which are bolted to

Plates

33 and 34 are welded respectively onto the struts 28 for the front bearing assembly and struts 35 for the 'rear bearing assembly which are similar in number and position to the struts 23. The two sets of eliminator bearing support struts 2S and 35 are secured to reinforced wall portions of the overall casing structure 10.

An annular air seal baffle plate 36 is secured between the connecting flanges of the washer and eliminator wall sections 10c, 10d of the casing and the inner edge of this baffle extends to the periphery of the blades 37 of the rotating eliminator assembly 30 to prevent high velocity air from traveling through the annular space defined by the wall ltld of the eliminator section and the outer edges of the eliminator blades 37.

The longitudinal axis of the bly 3th is offset slightly upward of the eliminator section lid of the apparatus so that there is a larger space underneath the rotating eliminator assembly than above it, this space being used to contain water in such quantity that the slight pressure head developed will force the water back through a scupper 38 and back into sump 15 from whence it can drain through pipe 16.

The air exit end of the rotating eliminator assembly 31 is surrounded by a seal assembly of solid sheet metal which consists of a tnuncated conical section 39 rigidly attached to the blades 37 of the eliminator assembly. A reversely extending truncated conical section 41 is rigidly attached to section 39 and extends rearward away from the eliminator. An annular shaped baffle plate 42 extending radially is secured to the truncated section 41. The truncated conical sections 39, 41 and the annular baffle plate 42 constitute the rotating components-of the air seal at this end of the eliminator assembly. The stationary parts of the seal are comprised of an annular baffle plate 43 extending radially outward from a cylindrical Wall section 44 which extends axially of the elimirotating eliminator assemfrom the longitudinal axis nator assembly 30 and lies inwardly of the truncated section 41. The cylindrical section 44 is fitted into a circular opening in the end wall plate 45 of casing 16 for the rotating eliminator assembly. A truncated conical baffle 40 is rigidly attached to this end plate 45 and extends into the area lying between the rotating conical section 41 and bafile plate 42. The drive shaft 31 of the rotating eliminator assembly terminates in a gear motor 46 which is mounted directly on the shaft. This gear motor has a torque arm 47 attached to the motor case and secured to one of the rear struts 35 so that it can effect rotation of shaft 31.

The rotating eliminator is comprised of an assembly of the radially extending planar blades 37 arranged in planes parallel with the axis of rotation and which rotates with the motor driven shaft 31. This is also illustrated diagrammatically in FIG. 18. In the illustrated embodiment the radially inner edge portions of the blades 37 are cut and bent outward from the plane of the plate in opposite directions as shown in FIGS. 27 to form a series of axially spaced loops 48 or piano hinge parts at each side of the blade. The hinge parts 48 of adjacent blades are interlinked and held together by means of rods 49 which pass through the hinge parts 48 and are made slightly longer than the length of the eliminator blades so as to project from each end thereof. The opposite end portions of the rods 49 are passed through apertures in end plates 51 which are secured fast to hubs 52 which are fitted onto shaft 31 and secured thereto such as by keying 50 or other suitable means. To keep the rods 49 from moving axially, annular rings 53 are removably secured to the plates 51 such as by bolts 54 and these rings include axially offset port-ions 53a which abut against the ends of the rods. Thus, in order to dismantle the eliminator blade assembly it is only necessary to remove the annular rings 53, thus exposing the ends of the rods 49 which can then be removed by grasping the ends and withdrawing them axially from the hinge portions 48 of the blades.

In order to substantially form a sealed cylindrical surface extending circumferentially under all of the eliminator blades 37 to prevent the flow of water laden air into and through the practically hollow hub portion of the rotating eliminator assembly 30, it will be seen from FIG. 2 that the interfitting laterally turned radially inner edge portions 48 of adjacent blades 37 also serve to close the separation between adjacent planar surf-aces of the blades in addition to their function as hinge parts.

Preferably, the radially outer portions of the eliminator blades 37 are held in spaced relation by means of rubber spacers 55. Each of these spacers as shown in FIGS. 810, there being one spacer for each eliminator blade, includes a cylindrical body portion 55a which makes a press fit within an opening 37a through the eliminator blade 37, a tapered socket 551; on one end and a tapered plug 550 on the opposite end of the same size as the socket. As shown in FIG. 8, the plug end 55c of one spacer unit is fitted into the socket end 55b on the spacer unit in the adjacent eliminator blade,

When motor 46 is energized thus causing shaft 31 and hence also the assembly of eliminator blades 37 to rotate, air washed in the washer chamber 13 and any water droplets entrained therein entering the channels formed between adjacent blades 37 will be caused to move in a helical path as it travels from one end of the eliminator blade assembly to the other. As explained, the pitch of the helical path taken by the air will be determined by the velocity of the air and by the rotational speed of the eliminator blade assembly. During the time the water laden air is enclosed within the blades of the eliminator it is being rotated at a reasonably high speed and each particle of water and other particles having mass are propelled by centrifugal force toward the outer edges of the eliminator blades. In addition to this centrifugal separationof the water from the air there also exists a collateral scrubbing action betwen the blades 37 which helps to film the water '8 out upon the surfaces of these blades so that it can come up to rotational speed more quickly. Water removed from the air by the rotating eliminator assembly is collected in the lower portion of the casing section 10d and is returned to the sump 16 for recirculation in the water header 21 after being passed through the filter 17 and pump 18.

In accordance with the invention, the eliminator blades 37 must be planar throughout substantially their entire working area in order to produce the desired centrifugally induced helically outward flow path of the water droplets separated out of the air stream. However, if completely planar blades as shown in the embodiment of FIGS. 1-10 are used and which are set at zero angle to the rotational axis, i.e. they lie in planes parallel with such axis, the air relative direction into the blades is at some definite angle to the blades dependent upon the velocity of the air and the air will tend to buffet at the blade ends. To avoid this, the end portions of the blades at the air entrance end to the eliminator may be given a slight twist in one direction and the end portions of the blades at the air exit end of the eliminator given a slight twist in the opposite direction. Such a modified blade construction is depicted in FIG. 12, the blades 56 being shown with oppositely directed twisted end portions 56a and 56b. These twisted portions thus match the entrance and exit directions of the air so that the air will enter and leave the eliminator more smoothly and will pass through the casing beyond the eliminator with virtually no swirl.

If desired, surface portions of the blades may be lightly embossed or roughened such as by bumps or ribs, in order to assure a more complete removal of water droplets from the air. This roughening of the blade surfaces serves to establish a discontinuous surface which is of assistance in breaking up the surface tension of the liquid being removed from the air stream so that minute water droplets have a better tendency to coagulate and thereby be more readily acted upon by the centrifugal force which is particularly high at the radially outer portions of the blades. The slight roughening of the blade surfaces may be effected throughout the area of the blade or it may be limited to certain areas. Roughening nearer the axis of rotation is of less advantage since in these areas the centrifugal force factor is less as is also the water volume.

FIGS. 13 and 14 show one suitable form of roughening for the surface portions of the blades 37 by the provision of a series of spaced ribs 57 which may be rectilinear or preferably, as shown, having a curvilinear configuration approximating the helical flow path of the water being centrifuged from the eliminator. The ribs 57 whether rectilinear or curved, are slanted generally in the direction of water flow through the eliminator, as shown. The ribbed portions of the blades may be limited to the air exit end of the blades, or as shown, they may be applied throughout the length of the blades.

In the embodiment of the invention illustrated in FIGS. 1-10, the eliminator section consists of a single rotating bladed assembly. If desired, a plurality of such bladed rotating assemblies may be cascaded along the rotational axis and driven independently so that adjacent assemblies can be rotated in the same or in opposite directions, and at the same or at different speeds. One advantage of rotating adjacent assemblies in opposite directions is that it varies the resulting vector of the peripheral speed of the blades relative to the axial velocity of the air flow through the apparatus. Thus, it approaches the action of a so-called broken plate eliminator but does not have the high static head characteristic of the latter.

The rotating eliminator assemblies nearer the air entrance end thereto can be driven at a comparatively low speed so as to remove most of the initial trash which otherwise would contribute to undesirable dynamic unbalance in the rotating assembly. The subsequently following eliminator assemblies can be driven at higher speeds since most of the trash will have been removed and hence, these are more clearly dynamically balanced 69 and will rotate satisfactorily at higher speeds without danger of excessive vibration. Thus, the rotational speed of each eliminator assembly can be virtually proportional to the weight of water or lint which the assembly must handle at its position in the cascaded group of assemblies.

FIG. 11 illustrates one practical embodiment for arranging a plurality of rotary eliminator assemblies in cascade along the axis of rotation. In this view, only the eliminator section of the complete air washer apparatus has been included. Here it will be seen that a plurality of rotating eliminator assemblies 58, each of generally the same construction as the eliminator assembly shown in FIGS. 1-10 are mounted on a through shaft 59 and are arranged for independent rotation by means of separate electrical motors 61 mounted on the outside of the casing d. These motors are coupled to their respective rotating eliminator assemblies by suitable drive means such as a chain and sprocket drive, one driving sprocket 62 being secured on the motor shaft and the other, driven sprocket 63 being secured on one of the hubs 64 of the associated rotary eliminator assembly 58, the sprocket chain 65 between the two sprockets being passed through an aperture established in the casing part 10d which encloses the eliminator assemblies.

As previously indicated, the motors 61 may be driven in the same directions and at different speeds, or the motors of adjacent eliminator assemblies maybe driven in opposite directions and also at the same or different speeds.

It has also been found advantageous to. operate a plurality of cascaded eliminator assemblies in the same direction but at different speeds. Thus, for example, considering a group of three adjacent assemblies, the two outer assemblies of the group can be rotated at the same speed, for example, 130 r.p.m., while the intermediate assembly can be rotated in the same direction but at a slower speed, for example, 34 r.p.m.

It is also possible to arrange the cascaded eliminator assemblies so as to maintain one assembly stationary while other assemblies adjacent thereto are rotated. This serves to re-direct the air stream between adjacent assemblies to bring about the most effective air entrance angle into the downstream eliminator assembly for the purpose of eliminating the entrained water particles.

The several eliminator assemblies 58 may have the same number of eliminator blades 37 or each assembly may have a different number of blades. Preferably the assembly 58 With the fewest blades is located upstream of the eliminator while succeeding assemblies as counted in the direction of air flow through the apparatus are provided with a greater number, e.g., progressively increasing numbers of blades. Used in this manner, the upstream assemblies 58 which receive the maximum amount of entrained water and dirt being washed from the air have less total surface area to contaminate and are more easily cleaned when cleaning becomes necessary, and the assemblies further downstream with more blades run in a much cleaner atmosphere and hence are capable of removing smaller water particles from the air. This latter function is possible since eliminating efficiency is, in part, improved when more blades are added to the hub, or when the eliminator blades are revolved at a higher rotational speed.

It has been explained that the eliminator may be positively driven in rotation by a motor or that it may be caused' to rotate by means of a windmill that can be automatically controlled so as to control the rotational speed of the eliminator. FIGS. and 16 illustrate an arrangement wherein the drive shaft 31 of the eliminator assembly 30 is driven by a windmill secured to the shaft, the blades of the windmill having a variable pitch controlled by a governor whose setting is made variable in accordance with the particular parameter involved such that the variable pitch windmill drive unit is secured to the drive shaft 31 directly behind the eliminator blade assembly 36 and downstream from the bearing support for the rear part of the eliminator drive shaft 31. In particular, it will be seen that the entire windmill assembly is built inside of and around a casing 66 which is keyed to eliminator shaft 31 by key 67. In this manner the eliminator shaft 31 is caused to rotate in unison with casing 66 which forms the bearing supports for four

windmill blades

68, 69. These four windmill blades are disposed 90 apart and extend from their hub section which is casing 66 and are aerodynamically correct airfoil sections. Blade shaft 71 extends through and is supported in hearings in casing 66 at

points

72, 73 so that each blade is rigidly supported but is free to rotate about the center line of shaft 71. Each of the blade shafts 71 has a pinion gear 74 firmly secured thereto so that it must rotate with its respective shaft. A face gear 75 is supported in-bearings on eliminator shaft 31 and is located on shaft 31 by a collar 76 and the hub section of casing 66. In this manner face gear 75 is maintained in operating contact with each pinion 74 and the two gears must always rotate together. Face gear 75 has two

axles

77, 78 fixed to and projecting perpendicularly from its face so that control gears 79, 80 can be rotatably mounted on face gear 75. Control gears 79, 80 are mounted at the proper radius from the center line of shaft 31 so that they engage to drive or be driven by a gear 81 which is supported in hearings on shaft 31 but retained in a fixed position on shaft 31 by collar 76. A drive stud 82 is rigidly attached to gear 81 and the two are made to rotate together. An air operated motor of the cylinderpiston type has its piston 83 and piston rod 84 flexibly mounted to stud 62 on one end and its cylinder 85 flexibly mounted on casing 66 by a clevis pin 86. Connected in this manner, the air cylinder 85 retains gear 81 in a fixed position so that it must rotate with shaft 31.

Control gear '79 has rigidly fixed to its face a fiyball control arm 87 and a flyball 88. Similarly, control gear 80 has rigidly fixed to its face a fiyball control arm 89 and a fiyball 919. It will be seen from FIG. 16 that the tWo control arms 87 and 89 are urged inwardly by springs 91 and 92, respectively. Control arm 87 is provided with a stop 93 and control arm 89 is similarly provided with a stop 94 so that they cannot come so far in that they touch the drive stud 82 or change the pitch of the windmill blades beyond a predetermined point.

The air operated motor is of the spring-return type so that the air pressure exerted against piston 83 achieves a force balance relationship which will fix the displacement of piston rod 84 with relation to variations in input control pressure, the latter being varied as a function of the change in the particular parameter utilized to control the speed of the eliminator. As shown in FIG. 15, the control air pressure is directed to the pitch changing mechanism through a tube 95, then through a rotary union 96 and finally through another tube 97 which leads to the interior of motor cylinder 85. In this manner, the air motor maintains gear 81 ina fixed position relative to casing 66 as long as piston rod 84 does not move. However, it is seen that an increase in air pressure within the cylinder 85 will cause gear 81 to rotate relative to shaft 31 through a certain number of degrees as determined by the stroke of piston rod 84 and the radius of the center line of drive stud 82 relative to shaft 31. When gear 81 is rotated relative to shaft 31, it can perform one of two functions or a combination of both. It can either rotate control gears 79, 80 about their individual axes or it can rotate the face gear 75 relative to shaft 31. This resetting tendency is described hereinafter.

Since the entire casing 66 and the mechanism therein is revolved at shaft speed,

fiyball

88 and 90 are acted upon by centrifugal force of a magnitude determined by the rotational speed of shaft 31. As centrifugal force on the unit is built up by bringing casing 66 up to a predetermined speed,

flyballs

88 and 90 along with their respective control arms 87 and 89 move outwardly away from shaft 31 carrying with them in a rotative manner, control gears 79, 86 to which they are individually attached. The fiyball assemblies will move outwardly until their force is balanced off by the inward force being exerted by the combination of springs 91 and 92. This operation will arrest any additional movement caused by centrifugal force as long as shaft 31 maintains a constant rotational speed. When the entire unit is at rest, the flyballs are positioned as shown in FIG. 16 and all of the

windmill blades

68, 69 are positioned relative to the air stream through the eliminator at their maximum angle of attack. That is to say, they are in a position relative to the air stream which will exert the greatest amount of torque on shaft 31 as the air moves by the blades at high velocity.

As the eliminator assembly 30 begins to come up to its operating speed, flyballs 38 and 90 rotate control gears 79 and 8t? against the immovable gear 31 so that their

axles

77, 78 cause face gear 75 to rotate relative to shaft 31 and in turn rotate the pinions 74 meshed with gear 75 so as to begin to feather the four windmill blades in unison. When the desired basic operating speed of the eliminator assembly 30 is reached, the windmill blades will have feathered to a position such that their combined lift exerts a torque on shaft 31 which is exactly equal and opposite to the air load and friction of the eliminator assembly which is being driven by rotation of shaft 31. Any increase in speed caused by, for example, a slight increase in the air velocity through the washer will cause the

flyballs

88, 90 to move further away from shaft 31 and further feather the Windmill blades so as to maintain a constant speed. Likewise, any decrease in eliminator speed from the designated condition will cause the fiyballs to move inwardly toward shaft 31 because of centrifugal force, and the windmill blades will increase in pitch until the increasing coefficient of lift will exert the required amount of torque to bring the rotating eliminator assembly back to the set basic speed.

Obviously, the final speed of the eliminator assembly in any one fixed position will be determined by the pitch of the air foiled shaped blades when the unit is at rest, such as depicted in FIG. 16. Therefore, a change in the final maximum speed can easily be accomplished by rotation of gear 81 relative to shaft 31 by the air pressure actuated piston 83 since it effectively changes the pitch of all windmill blades when they are at rest. This operation can be performed during high speed rotation of the eliminator assembly 3% since the pressure air admitted into cylinder 85, and which varies in pressure as a function of the controlling parameter, enters the speed control unit through the rotary union 96.

It will thus be seen from FIGS. 15 and 16, that the adjustable fiyball governor which has been described serves to continuously re-adjust the

windmill blades

68, 69 to maintain a selected basic operating speed for the eliminator assembly 30, and that this basic speed can also be automatically adjusted up or down in accordance with variation in a desired parameter such as the condition of the air in a textile room which is supplied with air from the outlet of the eliminator assembly.

Since a rotating eliminator with substantially planar blades should operate on a proportional basi relative to water droplet size, i.e. the large droplets should come out on the upstream side of the eliminator and the droplet size moving through the eliminator channel should continuously diminish until one either strips all of the liquid out or until, at a rotational speed which would be under that for complete elimination, a very fine droplet mist would issue from the eliminator. In this manner one is enabled to control in a very accurate manner the amount of boost or entrainment leaving the eliminator and thus obtain a completely controllable wet duct system by virtue of changing the rotational speed of the eliminator. Obviously, this speed control of the eliminator can also be obtained by driving the eliminator from a variable speed electric motor as in FIG. 1 which could be controlled as to speed by conditions in the room receiving air from the eliminator.

During operation of the eliminator, it is possible that some dirt, lint, and other particulate material may become stuck on the surfaces of the blades, and in the gaps between adjacent blades thus interfering with proper operation of the apparatus and increasing the static pressure losses. While dirt accumulation and clogging are not serious factors in the improved eliminator structure due to the fact that the blades are essentially planar throughout their area of contact with the air being passed through the eliminator, some dirt and clogging may occur and hence, it is advantageous if arangements are made for conveniently cleaning off the blades. FIG. 17 illustrates one suitable arrangement wherein it will be seen that a row of nozzles 101 project from a header pipe 102 inserted radially into the axial gap between the ends of adjacent eliminator assemblies 58 in such manner as to direct streams of water under considerable pressure longitudinally upstream and downstream through the assemblies to Wash out any particulate matter which may have become lodged between adjacent blades or on the blade surfaces themselves. It will be noted that each row of nozzles 101 extends from the inner to the outer edges of the blades thus assuring adequate clean-off of the entire surface area of the blades.

In addition to or in lieu of the radial row of flooding nozzles 101 we can provide one or more other flooding nozzles 191 located on that part of header 102 which extends longitudinally of and just inside the casing wall Gd. The one or more nozzles 101' are so oriented as to direct their discharge either in a truly radial direction inwardly toward the hub, or at a-slight angle to a radial line so as to also provide a turbine effect which can be used to effect a comparatively slow rotation of the eliminator assembly during cleaning. Motors 61 can also be operated at a slow speed for cleaning.

When it is desired to clean out the bladed eliminator assembly or assemblies if there be a plurality of them arranged in cascade as shown in FIG. 17, the apparatus is shut down which includes cutting off the water nozzles 24, 25, cutting off the fan 12 and cutting off the motor or motors 46, 61 which drive the bladed eliminator assemblies in rotation.

The flooding nozzles 101 are then turned on to operate for the desired time and can then be turned off and the eliminator assembly placed back into normal operation.

If desired, the cleaning sequence can be programmed to operate on a given cycle with the aid of a timer motor and the necessary switching devices which will switch the various operating components on and off at the proper times and in the correct sequence. Thus, for example, the cleaning cycle can be set up to provide the following sequence of operations:

(1) Cut off water to air washer nozzles 24, 25 by cutting off pump 18.

(2) Cut off fan 12 by de-energizing its electric motor drive.

(3) Cut on flooding nozzles 101 by energizing a solenoid control valve in header pipe 192.

(4) Cut off eliminator drive by de-energizing its electric motor drive 46 or 61.

Since the eliminator assembly 30, or assemblies 58 have considerable momentum due to their relatively great mass, the desired back flooding of the surfaces of the eliminator plates to clean them. can then take place while the eliminator assembly is running down to stand-still from its normal rotating speed following cut-off. After the eliminator assembly or assemblies have reached a standstill condition, their motors can then be re-energized to thus restart them, gradually bringing them back up to their normal rotating speed, the flooding nozzles 101 can then be cut oif, this being followed by cutting on fan 12 and restarting pump 18 to re-start the flow of air washer water from nozzles 24, 25. This entire cycle can be made to take place in the desired overall time which can be of the order of 30 seconds, and can be repeated at the desired intervals in an automatic manner by means of the timer mechanism.

If the back-flooding feature is applied to. the single eliminator assembly structure as shown in FIG. 1, the nozzles 101 would be placed at the downstream, or right hand end of the assembly 30 and these nozzles would be so oriented as to direct streams of water back along the surfaces of the blades 37 towards the left or entrance end of the assembly.

In the embodiments of the invention which have been described, the blades 37 of the eliminator assembly, or assemblies if there be two or more such assemblies arranged in cascade as shown in FIG. 18, are arranged in planes parallel to the rotational axis of the assembly. If desired, the blades may be arranged in planes disposed at an acute angle to the axis of rotation. Such a modified construction is illustrated in FIG. 19, it being noted that for a cascaded arrangement the blades 37 of one eliminator assembly are angled in one direction away from the axis while the blades 37" of an adjacent eliminator assembly are angled in the opposite direction with respect to the axis thus giving a herringbone effect. The oblique angled setting of the blades of the eliminator can also be applied to a construction in which there is but a single rotatable assembly.

In conclusion, it will be understood that while preferred embodiments of the invention have been disclosed and illustrated, various changes may be made therein in the specific construction and arrangement of component parts without, however, departing from the spirit and scope of the invention as defined in the appended claims.

We claim:

1. In a combined air washer and eliminator, the combination comprising a casing having an air inlet at one end and an air outlet at the, other end, motor driven iian means for moving the air stream to be treated through said casing between said inlet and outlet, a washer chamber located within said casing and including water spray means for effecting contact with the air, an eliminator chamber located within said casing on the downstream side of said Washer chamber, a rotatable shaft mounted bladed eliminator assembly located within said eliminator chamber, said eliminator assembly comprising a plunality of radially extending blades which are essentially planar between the air inlet and outlet edges thereof for producing a centrifugally induced helical outward flow path of liquid droplets separated out of the air st-r'eam, a windmill mounted on the shaft which mounts said eliminator assembly, said windmill being driven by the air stream passed through said washer and eliminator chamber and being provided with blades having adjustable pitch, and adjustable speed governor means on said windmill t or changing the pitch of said windmill blades, said speed governor means being responsive to a change in a parameter related to use of the air dischanged from said eliminator assembly for efiecting a corresponding adjustment in the setting of said speed governor means thereby to efiect a corresponding change in the speed of said windmill and eliminator assembly and hence a corresponding change in the amount of moisture removed from said air stream.

2. In a combined air washer and eliminator, the combination comprising a :casing having an air inlet at one end and an air outlet at the other end, fan means for moving air to be treated through said casing between said inlet and outlet, a washer chamber located within said casing including spray means for effecting contact with the air, an eliminator chamber located within said casing on the downstream side of said Washer chamber, a group of three coaaxially mounted rotatable eliminator sections arranged in cascaded relation within said eliminator chamber, each said eliminator section comprising a plurality of radially extending blades which are essentially planar between the inlet and outlet ends of the section for producing a centrifugally induced helical outward flow path of liquid droplets separated out of the air stream, and means for rotating all three eliminator sections of the group in the same direction, said rotating means including means for rotating the two outer eliminator sections of said group at the same speed, and means for rotating the intermediate eliminator section at a speed less than half that of said outer eliminator sections.

3. A combined air washer and eliminator as defined in claim 2 wherein the rotary speed of the intermediate eliminator section is of the order of one-fourth that of the two outer eliminator sections.

4. A combined air washer and eliminator as defined in claim 2 wherein said eliminator sections are provided with an increasing number of blades as relatedto the direction of air flow through the eliminator chamber.

References Cited by the Examiner UNITED STATES PATENTS 926,647 6/ 1909 Flossel 261- 991,157 5/1911 Kestner 5591 1,112,381 9/1914 Patitz 261-89 1,292,561 1/1919 Baldwin 55401 1,480,775 1/1924 Marien 55-407 1,511,834 10/1924 Marien 55401 1,864,803 6/1932 Clark 170 1,898,807 2/1933 Barnes 55-91 2,007,734 7/1935 Wergifosse 261--90 2,509,173 5/1950 Schreier et al 55404 X 2,922,489 1/ 1960 Hollingsworth 55217 2,932,360 4/1960 Hungate 55257 X 2,953,355 9/1960 Hungate 55-257 X 2,954,841 10/1960 Reistle 55404 X 2,962,116 11/1960 Hayes et al 55404 X 2,975,861 3/1961 Hay'es 55408 X 3,058,720 10/ 1962 Hart et a1. 55408 X 3,073,095 1/1963 Hungate 55257 3,073,096 1/1963 Hayes 55257 FOREIGN PATENTS 7,997 6/ 1902 Austria.

561,554 10/1957 Belgium. 1,009,096 2/ 1952 France.

904,260 2/ 1954 Germany.

284,312 5/ 1928 Great Britain.

332,859 7/1930 Great Britain.

732,622 6/ 1955 Great Britain.

ROBERT F. BURNETT, Primary Examiner.

Claims

1. IN A COMBINED AIR WASHER AND ELIMINATOR, THE COMBINATION COMPRISING A CASING HAVING AN AIR INLET AT ONE END AND AN AIR OUTLET AT THE OTHER END, MOTOR DRIVEN FAN MEANS FOR MOVING THE AIR STREAM TO BE TREATED THROUGH SAID CASING BETWEEN SAID INLET AND OUTLET, A WASHER CHAMBER LOCATED WITHIN SAID CASING AND INCLUDING WATER SPRAY MEAND FOR EFFECTING CONSTACT WITH THE AIR, AN ELIMINATOR CHAMBER LOCATED WITHIN SAID CASING ON THE DOWNSTREAM SIDE OF SAID WASHER CHAMBER, A ROTATABLE SHAFT MOUNTED BLADED ELIMINATOR ASSEMBLY LOCATED WITHIN SAID ELIMINATOR CHAMBER, SAID ELIMINATOR ASSEMBLY COMPRISING A PLURALITY OF RADIALLY EXTENDING BLADES WHICH ARE ESSENTIALLY PLANAR BETWEEN THE AIR INLET AND OULET EDGES THEROF FOR PRODUCING A CENTRIFUGALLY INDUCED HELICAL OUTWARD FLOW PATH OF LIQUID DROPLETS SEPARATED OUT OF THE AIR STREAM, A WINDMILL MOUNTED ON THE SHAFT WHICH MOUNTS SAID ELIMINATOR ASSEMBLY, SAID WINDMILL BEING DRIVEN BY THE AIR STREAM PASSED THROUGH SAID WASHER AND ELIMINATOR CHAMBER AND BEING PROVIDED WITH BLADES HAVING ADJUSTABLE PITCH, AND ADJUSTABLE SPEED GOVERNOR MEANS ON SAID WINDMILL FOR CHANGING THE PITCH OF SAID WINDMILL BLADES, SAID SPEED GOVERNOR MEANS BEING RESPONSIVE TO A CHANGE IN A PARAMETER RELATED TO USE OF THE AIR DISCHARGED FROM SAID ELIMINATOR ASSEMBLY FOR EFFECTING A CORRESPONDING ADJUSTMENT IN THE SETTING OF SAID SPEED GOVERNOR MEANS THEREBY TO EFFECT A CORRESPONDING CHANGE IN THE SPEED OF SAID WINDMILL AND ELIMINATOR ASSEMBLY AND HENCE A CORRESPONDING CHANGE IN THE AMOUNT OF MOISTURE REMOVED FROM SAID AIR STREAM.