CA1115528A

CA1115528A - Adjustable head machine

Info

Publication number: CA1115528A
Application number: CA327,925A
Authority: CA
Inventors: Herbert L. Weber; Charles W. Lake
Original assignee: Worldwide Blast Cleaning Ltd
Current assignee: Worldwide Blast Cleaning Ltd
Priority date: 1978-05-19
Filing date: 1979-05-18
Publication date: 1982-01-05
Also published as: JPS555282A; AR218723A1; EP0032161A1; HK46082A; BR7903080A; HK45982A; ZA792058B; NO820454L; DK204979A; GB1603308A; EP0005604A1; JPS58155172A; NO791612L

Abstract

"Surface cleaning machine"

Abstract A surface cleaning machine, of the kind in which abrasive grit is projected at high velocity against a surface to be cleaned. The machine has an upper hopper to receive grit carried by rebound and air flow from the zone being cleaned. Adjustable openings provide for controllable air exhaust upstream of the upper hopper which has a controllable outlet through which grit falls in the form of a curtain into a main, lower hopper. Air is drawn into the main hopper through a controllable inlet and flows through the curtain to remove dirt from the falling grit. The angle of the blast wheel can be varied, to vary the angle of impact of the projected grit on the surface in the cleaning zone.

Description

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Field of the invention Thi s invention relates to a surface cleaning machille of the kind in which abrasive grit is projected at high velocity - against a surface to be cleaned. ~`hus the surface is subjected to an abrasive blast which is produced for example by a vaned blast wheel rotati.ng at high speed, to fling or project the abrasive grit with great force on to the surIace so as to blast-clean from it all dirt. The abrasive grit used i5 usually fine steel shot and such material will be refe.rred to herein for brevity as "grit", Dirt to be cleaned from the . ~ . , .

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surface may be of various kinds, for example dus-t, paint, oil, rust, or otller contaminants or coverings, and mixtures of -them :
the~e will be referred to herein for brevity as "dir-t".

Description of the prior art \~\ arious machines of the type refer:red to are known, see for example British Patent Specification No. 1,ll96,~68 and U.S.
Patent Specifications Nos. 3$03~,262; 3,3809196; and 3,691,689 ~ machine of the kind referred to above may be required to clean various kinds of surfaces having various kinds o:E surface eontan1inants. For example a concrete iloox surface may be eovered with a mixtllre o-f oil and dust, or a metallic -tank surfaee may be covered with a mixture of paint and rus-t, and so on. But it has been found that satisfactory and quick cleaning of variolls surfaces and contaminations involves di:Eferent cleanina conditions. For example some surfaces and contaminations can be eleaned more easily than others : -thus a lighter weight of grit eould be used, or a less powerful blast effeet cou:ld he used, or a eombination of both. Existing machines of the type referred to eannot however give the necessary versatility, particularly in terms of varying the blast-cleaning effect of the grit on the surface to be cleaned It has been found in using machines of the kind referred to above that if grit is projected from a blast wheel at a maximum angle of approximately 80 to the surface to be cleaned, the blast-cleaning efeect is greates-t. Thus it is the practice to mount the blast wheel and its drive motor so that the grit is . .
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flung in a plane generally a-t right angles -to the axis of rotation of the ~heel along an inciclent pa-th inclined a-t 80 to -the horizontal, i-f the machine is used Io:r cleaning - a floor or o-ther horizon-tal surface lf the machine is usecl for cleaning a wall or other vertical surface, then the incident path will be a-t 80 to the vertica~ Yhen the grit :is projectet;
at the surl'ace a-t 80 thereto, there is a substantial rebollnd ef:L'eet, which is used, together with an air flow~ in reelaiming ; the grit for further use and in transporting the clirt :Cor subsequen-t removal from a part of the machine remote from the surfaee It has also been found that if the angle is reduced, the blast-eleaning efI'ect wi:Ll be reduced Thus for severe eonta~ina-tion, an angle of 80 eould be usecL, bllt for :Less ¦ severe eontamination, a lesser angle eould be usecl I Sulllmary of the invention ' ~he invention is therefore based on the problem o:L' pxovlding . a surfaee eleaning ~aehine O:e -the kind referred to above, whicl .i ean be readily used for eleaning di~ferent kincls of sur:races 1 20 with different kinds of surfaee eontaminants.
! Aeeording to this invention there is provided a s~lrface ~¦ eleaning machine of the kind in which abrasive grit is projected at high veloeity against a surface to be cleaned, the maehine eo~lprising:- -i) an enclosure with an opening -L;herein ii) sealing means disposed arotlnd the opening so as to I eontaet the surfaee to be eleaned and so as substantially I to retain abrasive grit and removed dirt within the - - enelosure :.
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iii) a projecting device for projecting abrasive grit a-t high velocity along an inciden-t path through the opening to a zone of -the surface to be c:leaned iv) a reclaim channel through wllich ~asses abrasive grit and dirt from -the cleaned surface zone v) an air inlet near the said opening for provi~ing \\an air fl~ through the reclaim ehannel vi) a main receiving con-tainer to receive a~rasive grit from the reelaim chamxe] for return o-~ the abrasive grit to the projeeting device vii) an additional reeeiving container to receive abrasive gri.t fron] the reclaim channel, the additional reeeiving ccntainer having an outlet of adjustably variable size viii)an opening ox openings Ior removal of air from the air flow, which opening or openings is or are disposed upstrea~ of the abrasive grit reeeived in the additional receiving container ix) the main reeeiving eontainer is disposed in sueh a position in relation to the said outlet tha-t abrasive grit passes in the form of a moving eurtain :from the addi.tional receiving container to the ~ain receiving eontainer x) an air inlet for flow of air into the main reeeiving eontainer, whieh air inlet is so disposed that air - passes through the moving curtain of abrasive grit to remove dirt therefrom.
Thus in ~he maehine of the invention the additional reeeiving container, preferably in the form of a hopper, eol].eets reclaimed gri-t ~ixed with dirt To avoid compaction -: , .
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of the grit in the additional receiving container, air pressure in that container may be reduced by removing air, preferably from the reclaim channel, upstream of the grit in the additional receiving container. The ~rit mixed with dirt can then flow through the outlet from the additional receiving container and this outlet is of adjustably variable size, so that the curtain of grit which flows from it into the main receivlng container or hopper can be maintained according to the weight or size of grit being used. It is to be noted that different grits will be used for different surfaces and contaminants. The air inlet into the main receiving container provides a flow of air through the curtain of grit entering the main container, to remove the dirt, which is generally of lighter weight than the grit, from the grit. In this way the dirt is blown away from the grit.
It is preferable that the air inlet into the main container be of adjus~ably variable size, so that the air flow through the main container can be varied to suit the various ~inds of operating condition. Thus for eY.ample for removal of dirt which is lightin weight, less air is required to flow through the main receiving container. The opening or openings provided for removal of air from the air flow is or are also preferably of variably adjustable size so that amount of air removed from the air flow can be controlled according to the particular operating requirements.
The projecting device for projecting the abrasive grit may be mounted in the machine so that the angle between the incident path of the projected abrasive grit and the surface to be ; cleaned can be adjustably varied. Thus if the projecting device is a vaned blast wheel rotatable at high speed, it may be so ., ounted in the ~lachine that its axis of rotation may be moved, to changc the ang]e of the incident pa-th. Pref'erably a driving ~otor, a shal't carrying the blast wheel, and the blast wheel, together with housing parts forming a channel along which the grit is projected, constitute a unit or head whicll is tiltable as a wllole about a hingeing axis.
l~len the angle between the incident pa-th and the surface to be cleaned is reduced, the rebound effect is reduced and it is necessary to rely more on a flow of air within the machine to reclaim the grit and remove the dirt. It is there~ore also necessary to provide for a greater i`low of air in the machine than has previously beell required. But witll kno~n machines, greater air :Elo~ produces a higher speed air f10W in the re-claim channel, partlcularly in that in some machines there is a venturi effec-t by virtue of the shape of the reclaim channel.
This produces various disadvantages : the grit, by virtue of its speed of movement and by virtue of the air pressure, can become compacted in the receiving container or hopper to which it is returned before being fed to the blast whee:L for re-use;
and the grit, by virtue of the i'riction i~lparted -to it by its high velocity motion in contact with the walls of the reclaim channel, becomes heated, so that some kinds of removed dirt, for example paint, clings to the grit and cannot be easily separated from the grit and evacuated to a dirt collector~ ~hich is usually a container to which strong suction is applied and which is usually also the source of the air flow through -the machine.
Thus, with a greater flow of air to transport dirt away fro~
the cleaned surface zone and along the reclaim path to the receiving container, the air may be largely removed from the .
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air flow so as to reduce the effec-t of the air flow on -the diK~t before it reaches the hopper Preferably -the opening or openings is or are in the form of louvres through ~hich the air and some of the dirt is removed to the dirt collector. Preferably also the louvres are adjustably movable to provide for varia-tion o-f~their area, to suit various operating conditions, whereby a greater or lesser amount of air can be removed from the reclaim channel.
The reclaim charlnel may be in the known form of a closed channel of rectangular cross-section, except that the cross- :
section is the same or virtually the same thro~ghout the leng-th of the channel from the cleaned surface zone to the additional receiving conta;.ner when the projecting device is in the posi~ion for maximum blast-cleaning effect.

Brief description o-f the drawin~s Figure 1 is a diagranlmatic section through a machine in accordance with the invention, as seen on the vertical plane in which the axis of' the blast wheel lies;
Figure 2 is a diagrammatic section as seen on a plane at ;~
right angles to the plane of Figure 1 and looking towards the blast wheel; and Figure 3 is a diagrammatic enlarged detail section of part of Figure 1 ; Description of the pref'erred embodiment Referring to the drawings, there is seen a surfacè cleaning maclline of the kind in which a suri~ace 1 to be cleaned is - 7 - :

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subjecte~ to fl ]li~ relocity l~lslst 2 of al~rasive grit l~hich ~last is produced b~ a vancl1 I)lnst ~ eel 3 1uoul1ted on a shaft 3A and driven ~y ~ hydraulic ulotor 3B at high speedl fol-e~a1l1ple 3~100 to 3850 r,p,ul. Tl~e n1aclline has an enclosure, forn1ed by the Va~`iOIlS plates seen in ~igure 17 as will be described, all~ the enclo~ul^e llas an opellillg 4 at the surIace l. ~The opening 4 is recl,a~ llar in plan alld has sealing means disposed arollnd it; this sealin~ IlleallS comprises double sealing ~.
strip me}nbers 5~, 5B, 5C and 5D respecti~rely at each side ol the openin~ and ill col1tact witll tlle sllrface l, The area of the ~.
surface l ~itllil1 t.ile opellin~ 4 at any time is the zone which is to be eleaned alld to whicll ablasivc 1uaterial in the for1n of grit 6 is :~ U1lg by tl~e blast w1lecl 3 along ~n incident path, In the position sho~Yn in full lines in ~igure l tlle incidellt path includes an angle of ap})lox-imately S0 ~ith tlle surface l. (Grit is indicated by tlle reference nl~ eral 6 in sevcral parts of the 1nachine), Tlle 1nac}1ine is l~1ollnted for u1o~c1llellt on a Ior~ard castor l~heel 7A and rear dri~en ~llleels 7B, 7C (I~'ig, 2) driven by a motor (not sllown), The grit rebollllds fro1u tlle surface zone -up into a reclaim chalmel 8 whicll is for1ued b~ a curved front reclaim channel plate 8A; parnllel spnced side pla~es o~ wllich one is seell at 8B; and a rear reclail~ chnllllel plat.e SC ~ ich is pivotally swingable about a hinge axis 9 fro1n the fllll line pOSitiOIl to the dot-dash line position sllo~1l; it will l)c secn tlmt ill the latter position the plate 8C is still below the Ill)per e(lgcs of the spaced side plates 8~, olle oL ~hicll llpper cd~cs is indicatcd at 8Bt. ~11e enclosllre is foruled b~ -Lhc rcclai1u cll~ cl alld nlso by the several plates cncl~osin~ the l~ st wheel : ~ f1ollt ~late lOA, rear plate lOB, :~
side plates lOC and top plat~ lOD.

The machine also includes a main receiving container in ~he form of a lower hopper 11 which includes inclined forward and rear plates llA, llB respectively; an additional receiving con-tainer or upper hopper 12 which also includes inclined forward and rear plates 12A, 12B respectively; and a return channel 13 for air and dirt and having upper and lower walls 13~, 13B
respectively. At the front of the machine is a dirt collector 14, into which dirt removed from the cleaned surface zone by the grit is sucked and stored, somewhat in the manner of a vacuum cleaner. The dirt collector 14 had an outer box-like casing 14A, the rear wall of which is open at 14B for movement of air and dirt into it. The collector 14 also includes dust bags 15 with support cages 15A. Air flow for the dirt collector and for the whole machine is provided by a fan 16 driven by a hydraulic motor 16A and having an exhaust 16B. A quick release, adjustably programmable electronic pulsar valve 16C and associ-ated air tank 16D are mounted on the casing 14A as shown.
The grit projecting device comprises the vaned blast wheel 3, with its shaft 3A and motor 3B, and the various plates enclos-ing the blast wheel. This constitutes a unitary structure or headwhich can be pivotally, adjustably moved about a hinge 17 mounted on the machine side plates 8B. In one embodiment, the blast wheel is 13~ inches in diameter and has seven curved vanes. An oper-ator's handle is seen at 18. The grit projecting device is mov-able from the full line position to the dot dash line position and can be fixed in either position, or in an intermediate position, by means not shown. In the full line or 80 position there is maximum cleaning effect and maximum grit rebound effect. These effects decrease progressively in ~arious positions of the head - . :.. : .. .: , . :
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wltil the minimum do-t-dash line position is reached "Yhen -the rebound eL'-fect ~annot be used to any ex-ten-t for ~rit reclaim, so tha-t reliance must be placed more on air -flow for reclaim of grit Gri-t is fed from the main hopper 11 to the blast wheel through a grit flo~ control valve 19 and ext0nsible Ilexible 'corrugated ducting 20. ~n extensible gas-controlled s-trut 21 supports the grit projecting device and is connected a-t its forward end +o brackets 21A fixed to the side plates ~B and at its rear end to brackets 21B on the plate lOA. The rear reclaim channel plate 8C is hingedly connected a-t 22 to the plate lOA, so that when the grit projecting device is moved~ thc plate 8C
moves with it about the hinge 9, and between the side pLates 8B
Within the housing formed by the several plates 10.~-lOJ) is a blast liner; this comprises an inner housing of heavy cas-t metal to con-tain the grit; it surrounds the blast wheel, as indicated at 23 (Fig. 2) and also deI'ines the path of the pro~
jected grit, as indicated at 24. A heavy liner is needed to withstand the ~ear caused by the gri-t; norma] steel plating as used for other parts of the machine would very qllickly 'be worn away The double front and rear sealing members 5A, 5B are all preferably of a resilient urethane strip. There is an additional outer front seal 5~. The double side sealing members comprise an inner manganese steel strip and an outer resilient urethane strip.
An air intake 25 to -the cleaning zone includes a brush-like screen 25A which permits entry of air, but retains grit and dirt.
The intake 25 is adjustable, for control of the amount of air dra~n in. The air intake is at the top of a channel 25B opening dowm~ardly near the surface 1 at the rear of the zone 4. The .

indrawn air is thus drawn downwardly in a controlled amoun-t to the zone 4i this keeps in motion any grit or dirt which tends to become idle and to accumulate near the rear sealing members 5B as the machine is moved forwardly, that is, to the right as seen in Figure 1.
Also as seen in Figure 1 the reclaim channel 8 is curved and parallel-sided in the full-line position, so that the air flow upwardly in the reclaim channel 8 is not subject in that position to a ~enturi effect and its speed is not increased.
The construction is such that its cross-sectional area at the level of the hinge 9 remains constant, even when the rear re-claim channel wall 8C is swung upwardly to the dash-dot line position, so that in the latter position the speed increase of the air flow is not significant. The air outlet, and one dirt outlet, from the reclaim channel 8 is by way o~ openings 26 having rockable louvres or flaps 26D, Figure 3. The construction of these flaps is not shown in detail; they are pivotally mounted and can be opened or closed to the required degree by an arrange ment of rollers 26A mounted on a rod 26B movable by a handle 26C
as indicated by the double-headed arrow in Figure 3. It will he noted that the air is largely removed from the air flow upstream of the surface 12C of the grit collected in the upper or addi-tional hopper 12, so that downstream of the louvres 26 the air speed and pressure is low whereby compaction of the grit in the .
upper hopper 12 is not increased.
~ he wall 13B fonms the upper surface of the upper hopper 12 and is a continuation of the wall 3A downstream of the louvres 26. The wall 13B is curved and provides fGr smooth flow of the grit to the upper hopper 12 and in practicem~st of the impact of the : ' .` ' : ,'. : "'' ' ~, : . . ,' ` :` , ~ ' . :

' ' ' reclai~led ~rit is .ll~sorbed b~ the surface 12C of the mass of reclai~ed grit already in thc upper hopper 12, From the upper llopper 12 the reclaimed grit falls through an outlet 27 ~hich is of adjustably variable size, havin~ a ~eight-controlled flap valve 27A and down into the main hopper 11, The flap ~alve 27A operates in dependence on the wei~ht of the grit in tlle Illper hopper. The less the ~rit, the less tlle fall and vice ~elsa, The grit -falls in -~he form of a cutain 6A. In the ~.~all llA of the maill hopper 11 is an air inlet of controllable size, havillg an adjustable flap valve 28A, through ~hich inlet air can be dra~-~n so as to pass through the falling curtain 6A of grit and reluove ~lore dirt from it; the removed dirt ~i-avels aloll~ the path indicated by the arrows through the return chanllel 13 and thence to the dirt collector 14 througil the ;
opening 14B, ~ass~e of the air through the cur-tain 6A assists in further cooling the latter~ as well as cleaning it.
Tlle cleaned and cooled ~rit collects as a mass in the lo~.~er or main hopper 11 ~nd is retllrned by ~ray of the controllable val~re 19 and ductin~ 20 to the blast ~.~heel 3, In one set of ~djusted oyerating conditions of the macllille of the invention, ~rit flo~ Irom the blast wheel is approximate]y S00 lbs. per millutc; air flo~ in the machine i3 1200 to 1600 cu,ft.
~er minutc ( ~.~llich is a number 1-1- to 2 times the shot flo~ num~er).
Tlle cros5-scctional ~rea of the reclaim channel at the level of the hinge n~is 9 is nppro~ lately 80 sq. inches (~hich is a mlmber 10~/o of the shot flo~. number or say 1 square inch per 10 lbs. of sllot per millllte). The size of the reclaim channel in the present elllbodimellt is 1~ inc}les ~ ~l~ inches, the latter dimellsion being in the pl~lle of th-` ~ra~ , The total maximum area of the louvres 26 is 27 sq. inches, (approximately one third of the area of the reclaim channel). The air intake is 18 sq. inches, (approximately two thirds of the area of the louvres). The above is one set of operating conditions. By adjustment of the various parts, other sets of conditions can be provided, accord-ing to the cleaning re~uirement, weight o~ shot, and so on. For example the degree of opening of the louvres can ~e varied, as can that of the valve 28, to control the air flow. If necessary louvres of different sizes could be interchangeably fitted.
Referring to Figure 3, the louvres 26D and the flap valve 28A can be operated in unison. This is shown diagrammatically as follows. Fixed to the handle 26C iS a pivot lever 26E which is connected by a link 29 to a pivot lever 28B fixed to the pivot shaft 28C of -the flap valve 28A. Thus when the handle 26C iS operated to adjust the louvres 26D, the flap valve 28A
is also adjusted. If the louvres 26D are adjusted to reduce the air flow through them, the flap valve 28A is adjusted to increase the amount of air entering the main hopper 11 through the inlet 28. The ~lap valve 27A is also connected to the pivot 20 lever 26E by a link 30 in yenerally similar manner, for control of the amount of grit falling through the opening 27.
It is also possible for the flap valve 28A to be connected to the pivot lever 26E, but not the flap valve 27A. Thus the openings 26 and 2 8 can be controlled in unison, but the opening 27 can be controlled separately, for example by a lever (not shown) connected to a pivot shaft (not shown) of the flap valve 27A, a weight ~not shown) being movably mounted on the lever.

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Claims

1. A surface cleaning machine of the kind in which abrasive grit is projected at high velocity against a surface to be cleaned, the machine comprising:-i) an enclosure with an opening therein ii) sealing means disposed around the opening so as to contact the surface to be cleaned and so as substantially to retain abrasive grit and removed dirt within the enclosure iii) a projecting device for projecting abrasive grit at high velocity along an incident path through the opening to a zone of the surface to be cleaned iv) a reclaim channel through which passes abrasive grit and dirt from the cleaned surface zone v) an air inlet near the said opening for providing an air flow through the reclaim channel vi) a main receiving container to receive abrasive grit from the reclaim channel for return of the abrasive grit to the projecting device vii) an additional receiving container to receive abrasive grit from the reclaim channel, the additional receiving container having an outlet of adjustably variable size viii) an opening or openings for removal of air from the air flow, which opening or openings is or are disposed upstream of the abrasive grit received in the additional receiving container ix) the main receiving container is disposed in such a position in relation to the said outlet that abrasive grit passes in the form of a moving curtain from the addi-tional receiving container to the main receiving container x) an air inlet for flow of air into the main receiving container, which air inlet is so disposed that air passes through the moving curtain of abrasive grit to remove dirt therefrom.

2. A machine according to claim 1 wherein air removal openings are arranged in a wall of the reclaim channel upstream of the additional receiving container, the openings being of adjustably variable size for the purpose of controlling the amount of air removed from the reclaim channel.

3. A machine according to claim 1 wherein the said air inlet of the main receiving container is of adjustably variable size for the purpose of controlling the amount of air passing through the moving curtain.

4. A machine according to claim 1 wherein the device for projecting abrasive grit is so mounted in the machine that the angle between the incident path of the projected abrasive grit and the surface to be cleaned is adjustably variable.

5. A machine according to claim 4 wherein the reclaim channel is of adjustably variable cross-sectional area.

6. A machine according to claim 1 wherein the said outlet is in the form of a pivotally mounted flap valve, opening movement of the said flap valve being caused by the weight of abrasive grit in the additional receiving container and closing movement of the said flap valve being caused by a weight adjustably movable along a lever connected to the pivot shaft of the said flap valve.

7. A machine according to claim 2 wherein the said air inlet of the main receiving container is of adjustably variable size for the purpose of controlling the amount of air passing through the moving curtain, the said air removal openings having movable louvres and the said air inlet having a movable flap valve, the movable louvres being connected to the movable flap valve for movement in unison.

8. A machine according to claim 7 wherein the said outlet is in the form of a pivotally mounted flap valve connected to the louvres and to the said movable flap valve for movement in unison.

9. A machine according to claim 1 wherein the additional receiving container is disposed above the main receiving container and in such a position in relation to the said outlet that the abrasive grit passes in the form of a falling curtain from the additional receiving container to the main receiving container.

10. A machine according to claim 1 wherein the air inlet near the opening is arranged to direct ail downwardly to the said zone of the surface to be cleaned, the inlet being of adjustably variable size for the purpose of controlling the air flow through the reclaim channel.

11. A machine according to claim 1 wherein said outlet is in the form of a pivotally mounted flap valve, opening movement of the said flap valve being caused by the weight of abrasive grit in the additional receiving container and closing movement of the said flap valve being caused by an adjustably movable weight.

12. A machine according to claims 1 or 3 wherein said opening for removal of air is located in said reclaim channel, said reclaim channel has an outside and wherein a plurality of louvers are pivotally mounted on said opening for removal of air, further comprising rollers mounted on a rod pivoted to a handle pivotally mounted on said outside of said reclaim channel, each of said rollers bearing against one of said louvers, thereby the pivoting of said handle moves said rollers in relation to said louvers thereby allowing said louvers to pivot.

13. A machine according to claim 11, wherein the device for projecting abrasive grit is so mounted in the machine that the angle between the incident path of the projected abrasive grit and the surface to be cleaned is adjustably variable.

14. A machine according to claim 13 wherein the reclaim channel is of adjustably variable cross-sectional area.

15. A machine according to claim 5, wherein the said outlet is in the form of a pivotally mounted flap valve, opening movement of the said flap valve being caused by the weight of abrasive grit in the additional receiving con-tainer and closing movement of the said flap valve being caused by a weight adjustably movable along a lever con-nected to the pivot shaft of the said flap valve.

16. A machine according to claim 2, wherein the said air removal openings have movable louvers.

17. A machine according to claim 15 wherein said air inlet near the opening is arranged to direct air downwardly to the said zone of the surface to be cleaned, the inlet being of adjustably variable size for the purpose of con-trolling the air flow through the reclaim channel.

18. A machine according to claim 1, wherein the said air inlet of the main receiving container is of adjustably variable size for the purpose of controlling the amount of air passing through the falling curtain, the air removal openings are provided in said reclaim channel having movable louvers, and the said air inlet for flow of air into the main receiving container has a movable flap valve, the movable louvers being connected to the movable flap valve for movement in unison.

19. A machine according to claim 8, wherein the said outlet is in the form of a pivotally mounted flap valve connected to the louvers and to the said movable flap valve of said air inlet for movement in unison.

20. A machine according to claims 1, 2 or 3, wherein said reclaim channel is a substantially unobstructed elongated chamber that extends substantially continuously to a level above said projecting device.

21. A machine according to any one of claims 5, 6 or 9, wherein said opening for removal of air is located in said reclaim channel, said reclaim channel has an outside and wherein a plurality of louvers are pivotally mounted on said opening for removal of air, further comprising rollers mounted on a rod pivoted to a handle pivotally mounted on said outside of said reclaim channel, each of said rollers bearing against one of said louvers, whereby the pivoting of said handle moves said rollers in relation to said louvers thereby allowing said louvers to pivot.

22. A machine according to claim 10, wherein said open-ing for removal of air is located in said reclaim channel, said reclaim channel has an outside and wherein a plurality of louvers are pivotally mounted on said opening for removal of air, further comprising rollers mounted on a rod pivoted to a handle pivotally mounted on said outside of said re-claim channel, each of said rollers bearing against one of said louvers, whereby the pivoting of said handle moves said rollers in relation to said louvers thereby allowing said louvers to pivot.

23. A machine according to claim 4 wherein said opening for removal of air is located in said reclaim channel, said reclaim channel has an outside and wherein a plurality of louvers are pivotally mounted on said opening for removal of air, further comprising rollers mounted on a rod pivoted to a handle pivotally mounted on said outside of said reclaim channel, each of said rollers bearing against one of said louvers, thereby the pivoting of said handle moves said rollers in relation to said louvers thereby allowing said louvers to pivot.

24. A machine according to any one of claims 4, 5 or 6, wherein said opening for removal of air is located in said reclaim channel, said reclaim channel has an outside and wherein a plurality of louvers are pivotally mounted on said opening for removal of air, further comprising rollers mounted on a rod pivoted to a handle pivotally mounted on said outside of said reclaim channel, each of said rollers bearing against one of said louvers, whereby the pivoting of said handle moves said rollers in relation to said louvers thereby allowing said louvers to pivot.

25. A machine according to any one of claims 7, 8 or 9, wherein said opening for removal of air is located in said reclaim channel, said reclaim channel has an outside and wherein a plurality of louvers are pivotally mounted on said opening for removal of air, further comprising rollers mount-ed on a rod pivoted to a handle pivotally mounted on said outside of said reclaim channel, each of said rollers bear-ing against one of said louvers, whereby the pivoting of said handle moves said rollers in relation to said louvers thereby allowing said louvers to pivot.

26. A machine according to any one of claims 10, 11 or 13, wherein said opening for removal of air is located in said reclaim channel, said reclaim channel has an outside and wherein a plurality of louvers are pivotally mounted on said opening for removal of air, further comprising rollers mounted on a rod pivoted to a handle pivotally mounted on said outside of said reclaim channel, each of said rollers bearing against one of said louvers, whereby the pivoting of said handle moves said rollers in relation to said louvers thereby allowing said louvers to pivot.

27. A machine according to claim 23, wherein said opening for removal of air is located in said reclaim channel, said reclaim channel has an outside and wherein a plurality of louvers are pivotally mounted on said opening for removal of air, further comprising rollers mounted on a rod pivoted to a handle pivotally mounted on said outside of said reclaim channel, each of said rollers bearing against one of said louvers, whereby the pivoting of said handle moves said rollers in relation to said louvers thereby allowing said louvers to pivot.

28. A machine according to any one of claims 14, 15 or 16, wherein said opening for removal of air is located in said reclaim channel, said reclaim channel has an outside and wherein a plurality of louvers are pivotally mounted on said opening for removal of air, further comprising rollers mounted on a rod pivoted to a handle pivotally mounted on said outside of said reclaim channel, each of said rollers bearing against one of said louvers, whereby the pivoting of said handle moves said rollers in relation to said louvers thereby allowing said louvers to pivot.

29. A machine according to any one of claims 17, 18 or 19, wherein said opening for removal of air is located in said reclaim channel, said reclaim channel has an outside and wherein a plurality of louvers are pivotally mounted on said opening for removal of air, further comprising rollers mounted on a rod pivoted to a handle pivotally mounted on said outside of said reclaim channel, each of said rollers bearing against one of said louvers, whereby the pivoting of said handle moves said rollers in relation to said louvers thereby allowing said louvers to pivot.

30. A machine according to claim 1 or 3, wherein the reclaim channel is of adjustably variable cross-sectional area.