US2039692A - Dust collector - Google Patents

Description

y 1936. H.-VAN TONGEREN 2,039,692

DUST COLLECTOR Filed Aug. 11, 1932 s Sheets-Sheet 1 May 5, 1936.

H. VAN TONGEREN DUST COLLECTOR Filed Aug. 11,1952

5 Sheets-Sheet 2 l 4 gwwmtoz He 'mamuw Win/1627967921, $1, 16?

' d wj y. 1936- v H. VAN TbNGREN 2,039,692

DUST COLLECTOR Fila Aug. 11, 1952 a Sheets-Sheet :5

l/YVE/YTDE. f/EE mwvus V00 Tb/YGEBE/V Patented May s, 1936 UNITED STATES PATENT OFFICE DUST COLLECTOR fiermannus van Tongeren, Heemstcde,

- Netherlands Application August 11, 1932, Serial No. ezsnoa In the Netherlands August 17, 1931 16 Claims. (01. 183-83) This invention relates to apparatuses for removing dust and other foreign bodies from dustladen air, flue-gases or the like and is particularly adapted for use 'in power plants, boiler- 5 houses, etc.

The'usual method of dust-separation and coll5 gases, is to be dedusted in an ordinary way, by

cyclones or dust-chambers.

The invention shows how these usual methods of dust-collecting may be improved by making use of a secondary gas-current, which always pro- 20 ceeds from the main current, when gases (or fluids) are forced to-follow a curved path and which secondary gas-current is known as the double eddy-current (German Doppelwirbel).

The existence of the double eddy-current is 5 known, but the great importance of it in connection with dust-collecting means has not heretofore been appreciated. Accordingly, the primary object of this invention is to provide for utilizing double eddy currents in securing high efliciency 30 in dust removing devices. The influence of the double eddy-current upon the path of the dustparticles is shown in the following drawings and description.

Figure 1 is a diagrammatic vertical sectional 35 view of a concentrator illustrating the formation of double eddy currents. M

Figure 2 is a diagrammatic horizontal view of the construction shown in Figure 1.

Figure 3 is a diagram illustrating the path of 40 the dust laden gases in the planes III-III of Figure 1.

Figure 4 is a diagram illustrating the path of flow of the gases on the line IVIV of Figure 1. I

Figure 5 is a vertical sectional view illustrating '45 the application of the principles of the invention to one form of embodiment.

Figure 5a is a vertical half-sectional view similar to Figure 5 but showing a modification of the casing. i v v 5 Figure 6 is a horizontal cross-sectional view taken on the line 6-6 of Figure 5.

Figure 7 is an elevation, partly in section, showing a construction embodying the invention.

Figure 8 is a horizontal sectional View of the 55 construction shown in Figure '7,

The double eddy-current in a. curve The Figures 1-4 show the double eddy-current in a hollow annulus l, The main current is indicated by the arrows 2 in Fig. 2. The arrows 3 and 4.in Fig. 1 indicate the two halves of the double eddy-current. 0n the right side of this figure the streamlines of the two halves of the double eddy-current are shown.

The dust-particles in the middle of the chan- 10 nel I are carried along to the periphery of the annulus by the gas-current of the double eddy-' current, which has here a rather great velocity, so that the dust particles in the middle of the channel reach the periphery of the annulus in a very short time, even if they are very fine. Their own velocity, due to the centrifugal action is of little importance, compared with the velocity of the double eddy-current (arrow 6 in Figs. 1 and 4). I

On the other hand the dust, which is situated near to the horizontal end-plates, has to overcome the countercurrent l in the Figures 1 and 3 and this is in general impossible, even for the coarser particles. The result is that they are carried along to the centre of the collector until they have reached the gas current in the middle part of the channel (arrow 6).

This explains why the dust-particles are not all to be found at the periphery, as one should expect, when the centrifugal force apparently has ha enough time to separate dust and gas.

The double eddy-current has nothing to do with the ordinary turbulence in the gases in rapid motion. The turbulence has the tendency to level the differences in the'loading of the gases at the centre and the periphery, but as this turbulent motion is very irregular, it only levels, but

it does not cause this motion of the gas and dust, which follows a fixed law. 40

- In the left side of Fig. 1 is shown how the double eddy-current sweeps the dust-particles in the edges of the casing, so that the loading of the gases is much higher in these places.

The right method of skimming-017 the dust Fig. 5 shows a chimney 8 provided with a circular or volute casing 9 around it.

It is usual to skim off the gases with the maxi mum loading at the periphery by a vertical slot of constant width, but in this figure the slot ID has the form of a U, so that in the edges, where the loading is maximum (even some times as great as at another place of the periphery) there is skimmed off more dust than would be possible 5 direction as the gas-current 2.

with the usual slot of constant width. In the Figures 7 and 8 the application of this slot 10 in a shunt-type dust collector is shown.

The gas-outlet with vanes new chance of being directed to the periphery.

Unfortunately the direction of the gas current here approaches the walls I 2 and I 3 and the opening to the chimney ll, so that a very important part of the dust escapes, even after the first col lision at i2 or i3. It would be of much more help should the dust come into collision in the middle part of the casing 9, because here the gas current is directed to the periphery, sothat the particles, after collision, are carried along away'from the opening to the chimney by the current 6 of Fig. 4.

Therefore the collectors, according to the invention, have vanes 14 in the opening II, which 'are directed opposite to the main current 2 in Fig. 2. These vanes H are very clear to be seen in Fig. 8. By the very sharp curve of the gases the dust particles are thrown outwards and collide with the vanes' H. After that, they are carried along with the current 6 and may reach the slot 10.

In the left part of Fig. 5 a diagram shows the loading of the escaping gases as a function of the place of outlet. Assuming that the vanes H extend over the whole height of the casing 9, the linesli-BC-D show the relative loading of the passing gases. The loading in the middle part BC is much less than the loading in the edges. The greater area of the parts ABGH and CDEF,compared with BCFG shows the gain in eflicienoy', forthe cleaner the gas in the outlet, the higher the eillciency. Without vanes, or with vanes in the same direction as the gas current, this result would not have been obtained, for it is necessary that the dust-particles come into collision in the middle part of the collector-outlet.

Line KL shows the loading of the gases when the outlet H has no vanes, or vanes in the same The loading depends entirely upon the'angle of the vanes; the more the vanes are directed tangentially, or the sharper the curvature of the annulus and the more the dust collides, the lower is the loading The placing of vanes ll in the opening II is also known, but when directed forwardly to decrease the resistance of the collector they decrease also I the efliciency of the dust-collecting. Even the directing of the vanes opposite the gas-current 2 is known, but what has not been known heretofore is that the greatest advantage is only obtained when the vanes I4 are directed as last'mentioned and placed in that part of the collector where the double eddy-current 3 and I (Fig. 1) has a velocity 6 to the periphery which carries along the particles after collision.

The emciency increases with the number of the vanes. It is desirable to make the vanes l4 so that they may be pivoted or turned round their axes. In the collector, shown in the Figs. 7 and -.8. this brings the possibility of adaptation of the angle of the vanes to the boiler-load. At peakload the vanes are opened very wide and then the resistance of the collector is even less than it would be without any vanes. At the same resistance, the collector could be smaller, which is not only cheaper, but has also. the advantage that the velocity of the main current at the lower loads will be suilicient to separate the dust from the gas. With the lower load the vanes are more nearly shut and their separating action increases. This neutralizes the loss of dust-collecting efllciency by the lower velocity of the main current, so that a constant emciency at very diflerent loads may be obtained by the use of pivoted vanes.

Dust-collecting gutters In many cases one can make use of the property of the double eddy-current to sweep the dust into .the corners of the casing (Fig. l).

If the channel 9 of Fig. 5 should be provided with the dust-collecting gutters l5 (as shown in Fig. 5a) a great part of the dust would assemble there and be carried along in a very concentrated state. The currents I would then drag along less dust to the centre.

Shunt-type collector A dust-collector in which are embodied many of the improved constructions which have been heretofore described is shown in the Figures 7 and 8. The dust-laden gases enter at 41 into the casing 9, shown in Fig. 5, with vanes Id at the outlet. The skimming place I0 is U-shaped and leads to the shunt-current-cyclone 48. This collector has the same efliciency as a very large direct-type cyclone and a lower resistance. By the pivoted vanes I4 the quantity of gases escaping to the chimney is regulated. At peak load the vanes are opened widely but at 25% load the vanes are nearly shut off, so that the cyclone 48 gets practically all the gases and is charged constantly, independent of the boiler-load. This shunt-type collector has therefore a constant emciency at all loads, which is as high as that of a very good direct-type cyclone.

Although it would be possible to give yet more examples of constructions in which is made use of the double eddy-current in a favourable way,

these will sufllce to show the great importance of this secondary current in connection with dustcollecting.

What I claim is:-

1. Means for removing dust and other foreign matter from air and other gases comprising a casing having end walls and a curved sidewall, the side wall having an air or gas inlet opening, an air or gasinlet conduit communicating tangentially with said casing through said air or gas inlet opening, an air or gas outlet conduit extending through an end wall of the casing into the latter in spaced relation to the side wall thereof, said outlet conduit having an inner open end spaced from said end wall of the casing, the side wall of the casing also having a dust outlet opening, said dust outlet opening being at least in part coextensive axially oi the casing with the air or gas inlet opening and in part coextensive'axially of the casing with a portion of the casing which lies between the plane of the inner open end of the air or gas outlet conduit and the end wall of the casing through which said conduit extends, a part of said dust outlet opening which lies between the plane of the inner open end of the air or, gas outlet conduit and the end of the casing through which said conduit extends being widened circumferentially of the casing, and a dust outlet conduit communicating tangentially with said casing through said dust outlet opening and oppositely with respect to the air or gas inlet conduit.

2. Means for removing dust and other foreign matter from air and other gases comprising a casing having end walls and a curved side wall, the side wall having an air or gas inlet opening, an air or gas inlet conduit communicating tangentially with said casing through said air or gas inlet opening, an air or gas outlet conduit extending through an end wall of the casing into the latter in spaced relation to the side wall thereof, said outlet conduit having an inner open end spaced from said end wall of the casing, the side wall of the casing having a dust outlet opening the middle plane of which is substantially coincident with the middle plane of the air or gas inlet opening, said dust outlet opening being at least in part coextensive axially of the casing with a portion of the casing which lies between the plane of the inner open end of the air or gas outlet conduit and the end wall of the conduit through which said conduit extends, the casing being of enlarged diameter between the plane of the inner open end of the air or gas outlet conduit and the end of the casing through which said conduit extends to provide a circumferentially extending gutter opening into the casing, the dust outlet opening extending across at least a portion of the casing which isof enlarged dimeter, and a dust outlet conduit communicating tangentially with said casing through said dust outlet opening and oppositely with respect to the air or gas inlet conduit.

3. Means for removing dust and other foreign matter from air and other gases comprising a casing having end walls and a curved side wall, the side wall having an air or gas inlet opening, an air or gas inlet conduit communicating tangentially with said casing through said air or gas inlet opening, a pair of air or gas outlet conduits extending through said end walls, respectively, into the casing in spaced-relation to the side wall thereof, said outlet conduits each having an inner open end spaced from the related end wall of the casing, the side wall of the casing also having a dust outlet opening, said dust outlet opening being at least in part coextensive axially of the casing with portions of the casing which lie between the planes of'the inner open ends of the air or gas outlet conduits and the related ends of the casing, respectively, parts of said dust outlet opening which lie between the planes of the inner open ends of the air or gas outlet conduits and the related ends of the casing, respectively, being widened circumferentially of the casing, and a dust outlet conduit communicating tangentially with the casing through said dust outlet opening and oppositely with respect to the air or gas inlet conduit.

4. Means for removing dust and other foreign matter from air and other gases comprising a casing having end walls and a curved side wall, the side wall having an air or gas inlet opening-an air or gas inlet conduit communicating tangentially with said casing through said air or gas inlet opening, a pair of air'or gas outlet conduits extending through said end walls, -respectively, into the casing in spaced relation to the side wall thereof, said outlet conduits each having an inner open end spaced from the related end wall of the casing, the side wall of the casing having a dust outlet opening, the middle plane of which is substantially coincident with the middle plane of the air or gas inlet opening, said dust outlet opening being at least in part coextensive axially of the casing with portions of the casing which lie between the planes of the inner open ends of the air or gasoutlet conduits and the related ends of the casing, respectively, the casing being of enlarged diameter between the planes of the inner open ends of the air or gas outlet conduits and the related ends of the casing respectively, to provide inwardly opening circumferentially extending gutters, the dust outlet opening extending across at least a portion of each of said gutters, and a dust outlet conduit communicating tangentially with the casing through said dust outlet opening and oppositely with respect to the air or gas inlet conduit.

5. Means for removing dust and other foreign matter from air and other gases comprising a casing having. and walls and a curved side wall, the side wall having an air or gas inlet opening, an air or gas inlet conduit communicating tangentially with said casing through said air or gas inlet opening, an air or gas outlet conduit ,extending through an end wall of the easing into the latter in spaced relation to, the side wall thereof, said outlet conduit having an inner open end spaced from said end wall of the casing, the side wall of the casing. also having a dust outlet opening, said dust outlet opening being at least in part coextensive axially of the casing with the air or gas inlet opening and in part coextensive axially of the casing with a portion of the casing which lies between the plane of the inner open end of the air or gas outlet conduit and the end wall of the casing through which said conduit extends, the casing being of enlarged diameter between the plane of the inner open end of the air or gas outlet conduit and the end 'of the casing through which said conduit extends, to provide a circumferentially extending gutter opening into the casing, the dust outlet opening extending across at least a portion of said gutter and, within the limits of the gutter axially of the casing, being widened circumferentially of the casing, and a dust outlet conduit communicating tangentially with said casing through said dust outlet opening and oppositely with respect to the air or gas inlet conduit.

6. Means for removing dust and other foreign matter from air and other gases comprising a casing having end walls and a curved side wall, the side wall having an air or gas inlet opening, an air or gas inlet conduit communicating tangentially with said casing through said air or gas inlet opening; a pair of air or'gas outlet conduits the air or gas outlet conduits and the related ends of the casing, respectively, the casing being of enlarged diameter between the planes of the inner open ends of the air or gas outlet conduits and therelatedends of the casing, respectively,

to provide inwardly opening circumferentially extending gutters, the dust outlet opening extending across at least a portion 'of each gutter and, within the limits of eachgutter axially of the casing, being widened circumferentially'of 7 to the air or gas inlet conduit.

7. Means for removing dust and other foreign matter from air and other gases comprising a I casing having end walls and a curved side wall, the side wall having an air or gas inlet opening, an air or gas inlet conduit-communicating tangentially with said casing through said air or gas 1 inlet opening, a pair of air orgas outlet conduits extending through said end -walls,"respectively,

' into the casing in spaced relation to'the side wall thereof, said outlet conduits each having an inner open end spaced from the related end wall of the casing, vanes extending between the inner ends of said air or gas outlet conduits, said vanes being disposed reversely with respect to the direction of flow of air or gas through the casing, the side wall of the casing also having a dust outlet opening, said dust outlet opening being at least in part coextensive axially of the casing with portions of the casing which lie between the planes of the inner open ends of the air or gas outlet. conduits and the related ends of the casing, respectively, and a dust outlet conduit communicating tangentially with the casing through said dust outlet opening and oppositely with respect to the air or gas inletconduit.

8. Means for removing dust and other foreign matter from air and other gases comprising a casing having end walls and a curved side wall, the side wall having an air or gas inlet opening, an air or gas inlet conduit communicating tangentially with said casing through said air or gas inlet opening, an air or gas outlet conduit extending, through an end wall of the casing into the latter in spaced relation to the side wall thereof, said outlet conduit having an inner open end spaced from said end wall of the casing, the side wall of the casing also having a dust outlet opening. said dust outlet opening being at least inpart coextensive axially of the casing with a portion of the casing which lies between the plane of the inner open end of the air or gas outlet conduit and the end wall of the casing through which said conduit extends, both the air or gas inlet opening and the dust outlet opening being at least in part coextensive axially of the casing with that portion of the casing lying inwardly of the inner open end of the air or gas outlet conduit, a part of said dust outlet opening which lies between the plane of the inner -to the air or'gas inlet conduit.

9-. The combination as set forth in clairn 8 in which vanes extend inwardly from the inner open end of the airor gasoutlet conduit, and in which said vanes are disposed reversely with respect to the direction of flow of air or gas through the casing.

10. Means for removing dust andother foreign matter from air and other gases comprising a casing having end walls and a curved side wall,

the side wall having an air or gas inlet opening, an air or gas inlet conduit communicating'tangentially with said casing through said air or gas inlet opening, a pair of air or gas outlet conduits extending through said end walls, respectively,

into the casing in spaced relation to the side wall thereof, said outlet conduits each having an inner open end spaced from the related end wall of the casing, the side wall of the casingv also having a dust outlet opening, said dust outlet opening extending from end to end ofthe casing and adjacent to the ends of the casing being-widened circumferentially of the casing, anda dust outlet conduit communicating tangentially with the casing'through said dust;outlet opening and oppositely with respect to the air or gas inlet conduit, the air inlet opening being coextensive axiallyof the casing with at least that part of the casinglying between the inner ends of the air or gas' outlet conduits.

11. The combination as set forth in claim 10 in which vanes extend between the inner ends of the air or gas outlet conduits and in which saidvanes are disposed reversely with respect to the direction of flow of air orgas through the casing.

12. The combination as set forth in claim 7 including means for adjusting the vanes to'vary the areas of the free spaces therebetween.

l3. Means'for removing dust and other foreign matter from air and other gases, comprising a casing having end walls and a curved side wall, the side wall having a gas inlet opening, a gas inlet conduit communicating tangentially with-said casing through said gas inlet opening, a gas outlet conduit passing through an end wall into the casing in spaced relation to said side wall, said conduit havingan opening extending throughout a part of its length and constituting the sole outlet i'or the gases discharged through said conduit, vanes for said opening, said vanes being substantially oi. equal length on each side of a plane transverse to-the side wall of the casing by which plane the volume of the space included 'within the casing is divided substantially equally, the side wall of the casing also having a dust outlet opening at least in part coextensive axially of the casing with those portions of the gas outlet conduit comprising the vanes together with the portions of the said outlet conduit on either side of the vanes, and a dust outlet conduit communicating tangentially with said casing through saiddust outlet opening and oppositely with respect to the air or gas inlet conduit.

14. Means for removing dust and other foreign matter from air and other gases, comprising a casing having end walls and a curved side wall,

the side wall having a gas inlet opening, a gas inlet conduit communicating tangentially with said casing through said gas inlet-opening, a gas outlet conduit passing through an end wall into the casing in spaced relation to said side wall, said conduit having an opening extending throughout a part of its length and constituting the sole .outlet for the gases discharged through said outlet, vanes'forsaid opening, said vanes being substantially of equal length on each side of a plane transverse to the side wall ofthecasing by which plane the volume of the space included within the casing is divided substantially equally,.- the side wall'of the 'casing also having a dust outlet opening at least in part coextensive axially of the easing with those portions of the gas outlet conduit comprising the'vanes together with the portions of the said outlet conduit on either side of the vanes, and a dust outlet conduit communicating tangentially with said casing through said dust outlet opening andoppositely with respect to the air or gas inlet conduit, parts of said'dust opening being widened circumterentially o! the casing.

15. Means for removing dust and other foreign matter from air and other gases, comprising a casing having end walls and a curved side wall, the side wall having a gas inlet opening, a gas inlet conduit communicating tangentially with said casing through said gas inlet opening, a gas outlet conduit passing through an end wall into the casing in spaced relation to said side wall, said conduit having an opening extending throughout a part of its length andconstitutlng the sole outlet for the gases discharged through said conduit,

vanes for said opening, said vanes being substantially of equal length at each side of a plane transverse to the side wall of the casing by which plane the volume of the space included within the casing is divided substantially equally, and in which the said vanes are so disposed as to cause the gas to make a sharp turn from the direction of flow to escape through the vanes, the side wall of the casing also having a dust outlet opening at least in part coextensive axially of the casing with those portions or the gas outlet conduit comprising the vanes together with the portions of the said outlet conduit on either side of the vanes, and a dust outlet conduit communicating tangentially with said casing through said dust outlet opening and oppositely with respect to the air or gas inlet conduit.

16. Means for removing dust and other foreign matter from air and other gases, comprising 9. casing having end walls and a curved side wall, the side wall having a gas inlet opening, a gas inlet conduit communicating tangentially with said 5 casing through said gas inlet opening, a gas outlet conduit passing through an end wall into the casing in spaced relation to said side wall, said conduit having an opening extending throughout a part of its length and constituting the sole out- 10 let for the gases discharged through said conduit, vanes for said opening, said vanes being substantially of equal length at each side of a plane transverse to the side wall of the casing by which plane the volume of thespace included within the casing is divided substantially equally, and in which the said vanes are so disposed as to cause the gas to make a sharp turn from the direction 01' flow to escape through the vanes, the side wall of the casing also having a dust outlet opening at least in part coextensive axially of the casing with those portions of the gas outlet conduit comprising the vanes together with the portions of the said outlet conduit on either side of the vanes, and a dust outlet conduit communicating tangentially with said casing through said dust outlet opening and oppositely with respect to the air or gas inlet conduit, parts of said dust opening being widened circumierentially o! the casing. 30

H. VAN TONGEREN.

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