DE1885388U - MULTIPLE FLEECE VACUUM COLLECTORS FOR GASES. - Google Patents

Description

RA. m 026 * 1 1.1153

Pat * -

Apparatebau Rothemühle
Brandt & Kritzler

Rothemühle U / Olpe i / W.

Utility model registration. . -....-. ■ "" ■ " ^Λ

"Establishment of cyclone separators to increase the suction of the vortex sink and the separation performance" with a given pressure requirement ¹ "

The innovation relates to mechanical dust extraction systems, which consist of a large number of individual cyclone separators connected in parallel. Each of these cyclones has an axial or tangential inlet for the uncleaned gases as well as a. clean gas pipe arranged axially to the cyclone, and the gases from their direction of entry are within each cyclone; diverted into the corresponding ^v against set exit direction. Here, the thrown-out dust is discharged through the dust outlet opening: which is arranged opposite the clean gas outlet as shown in the figures -T, Z, 5, and 6. . ^; . -----

Such. Yi eleven cyclone separators are known to have the. Disadvantage.: that when individual cyclones are acted upon differently - ". an exchange of gas takes place between them, which is associated with a considerable discharge of dust from the bunker and from the less polluted cyclones." cloning into the clean gas :. ' ^J. - :.

There are various approaches to remedying this disadvantage. and \. ': -. Facilities known as, the suction, a certain amount of Sas from the bunker, which creates such a negative pressure in this ■ -. should that no gas in. a less polluted cell ": libels tr ömeii: can ..

It is further from smoking and research work "began; that sfch -in-such a cyclone a flow ver3? La, af j.in. form ^: a ^ Wirbei ^,; - ;: 1 senlce sets. The course of the axial The characteristics of such a flow are shown in Figure 1 at different altitudes, in each case over the corresponding cyclone diameters, - - _:

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^(:; β, record book of the 1 / f-DI achausschusses te for -Staub chnik .19 53 "to cyclone separators investigation '.) corresponding to the Yersuchsergebnissen of ler lindeil. - As ... this illustration shows, the flow is directed downwards on the outer circumference of the cyclone and in its beacon: and can thus reach the dust particles in this area - in the direction of the- ..: transport dust outlet downwards *. In contrast, 1st. however _:. in the vicinity of the cyclone axis an upward-facing one _; .Countercurrent. : to see, the suction of which continues down into the bunker, as well as the downward-directed axial velocity components on the circumference, of the external eddy current. - apparently . must with airtight dust bunker in the Zyklonmltt.e _:. a countercurrent exist, which the. same amount of gas that flows downwards at the outer circumference, again, upwards; leads. This upward flow is of course very unfavorable for the separation, because it can suck in a considerable part of the already separated dust from the dust bunker and back again. - Carry it along through the cyclone into the inlet gas duct. It's about it. : attempting remedies known by; one under the. Dust is discharged by arranging a disk in order to close the vertebral joints at these points. end and thus avoid the suction from the bunker into the cyclone .:

It is also known that such discs are a central one. Hole to 'give '"- in order to allow a certain small intake, which with a discharge flow around the disc, out; the cyclone" into the. Bunker ... is to be returned. \ _; . . \ ^:. V.;.; .. '.- "-."

These measures have a Yersehl-eGhter the dedusting degree. _ / ZurlOlge because the Ifirbelsenk'e "schwä & han and the Figure; opening 1 and 3 shown ^ ^ axial speed ^ he ^ etlung in the dust _discharge.. Imte ^r rbinden-: Ode ^ the Axiälge.schwindigkei.ten's. -fcark decrease... - ". ■■ '-" ■ "; -. . ..; ^ ;. ; '■

This is where the invention comes in - by using an independently operating procedure using simple means. That makes the gas exchange between the differently acted upon cyclones harmless insofar as the / entrained dust in or in the. - ^:; .How the dew discharge opening ejected ^: and_ into the bunker. . is returned "..:"". ^: . '_{-,:' -:} ...:. '-" V "" - "- ' - ■■ -: '.: \. -""/ ■ ^: ; .. ' .:

It is based on the "distribution of the axial components of the velocity over the cyclone diameters in the area of the dust discharge opening" shown in Figure 1 and from the observation made in the invention that the vortex depression in the cyclone is at the height of the cyclone axis due to the axial velocity directed into the cyclone a heavily filled bunker sucks in a lot of dust, but that it does not pass the cyclone all the way to the clean gas pipe if the rotational speeds u and thus the centrifugal forces m. u in the dust discharge opening and in the cyclone cone

r
are sufficiently large just above the dust discharge opening. The portion of dust sucked up from the bunker can then be thrown out of the vortex flow again in the area of the dust discharge opening or immediately above it and conveyed back into the bunker at the axial speed leading into the bunker on the outer ring cross-section of the lower cyclone cone.

Tests made for this purpose with larger and smaller dust discharge openings showed that with larger discharge openings the circulation

speeds u and. so that the centrifugal forces m. u and the axially

components in the area of the dust discharge opening are relatively small will. There will then only be a smaller proportion of what is inside Upward flow of dust extracted from the bunker through this small Centrifugal forces in the outer singing cross-section of the vortex flow is thrown out, and a relatively large proportion of this dust that is sucked up gets into the clean gas pipe "with which the Degree of dust removal considerably reduced. Against this, however, was a reduction in the size of the dust discharge opening found that the centrifugal forces within the examined area are approximately reversed increase proportionally with the cross-section of the dust discharge opening. In this case, the upward through the pull of the directed internal vortex flow from the bunker discharged dust if the dust discharge opening is sufficiently reduced in size by the achieved increase in centrifugal forces in this area practically completely back into the outer ring cross-section of the downward eddy flow ejected and returned to the bunker with this external current. -

The larger centrifugal forces in smaller dust discharge cross-sections ensure a speedy discharge of the dust in the federal \ ker and prevent the accumulation of dust at this most sensitive point of the cyclone, where the large Circumferential speed has a strong abrasive effect of the gas, which is heavily enriched with dust when the dust discharge opening is larger would be caused. Secure the increased centrifugal forces a continuous dust discharge and prevent a stronger dust accumulation in the cyclone, which a dust discharge into the clean gas would favor .. Is there an essential result in this way Improvement of the overall degree of dedusting through the continuous Discharge of the dust and by being ejected from the Bunker of sucked back dust.

Since the static pressure in the bunker is very different, the pressure difference between the bunker and the clean gas duct was determined in tests measured. It was confirmed to be found in agreement with similar test results from Ter Linden, 'that the negative pressure in the bunker proportional to the dynamic pressure of the circulation speeds within the dust discharge opening and roughly vice versa increases proportionally with the orbit radius of this flow.

Figure 4 shows the dependence of this negative pressure τ Λ Pt ₀₁₁ ⁼ ι P>) _U ί P _re T ^om diameter of the dust from the opening at a given pressure (constant gas throughput). The curve shape shown with these measuring points is, with a very close approximation, a hyperbola of the law r _g . 4 p, = constant.

The fact that also the back pressure of the rotational speeds approximately inversely proportional to the orbital radius of the flow increases (r. u = constant), was not only in agreement from the aforementioned investigations by Ter linden, but also already-by Shepherd and Lapple ("! low Pattern and Pressure Drop, Industrial and Engineering Chemistry Vol. 31, ETo, 8 ").

To explain this law, which is known per se, are in Figure 2 after the test results of Ter Linden the Circulation velocities of the vortex flow in different

- 5th

Altitudes within the cyclone are drawn. How out of this As can be seen in the figure, the rotational speeds u are decisive for the centrifugal forces in the entire vortex space of the cyclone. they climb downwards to the dust discharge opening at corresponding to the decreasing cyclone radii r. (For comparison is in the pictures and 2 also the course of the radial velocity components drawn in dotted lines).

It is therefore up to us with the relation found by our experiments. Λ. ρ>. _η = constant and the well-known regularity r „. ue = ■ r. u ^ = constant by choosing the most favorable proportions between the gas inlet radius r and the dust discharge radius r with an unchangeable pressure expenditure and generally with any cyclone size, the centrifugal forces in the area of the dam opening are considerably increased and at the same time the overall degree of dedusting by increasing the bunker negative pressure Ji P ₁₀₁₁ to increase significantly.

The tests, confirmed by practical experience, led to to the fact that the beneficial effect described small dimensions of the Dust discharge opening is sufficiently achieved if the diameter the dust discharge opening smaller than 1/3 of the diameter of the gas discharge opening of the cyclone is made, with between the Bunker and the clean gas pipe results in a pressure difference that is greater is T / 3 of the flow resistance of the cyclone from the gas inlet opening to the end of the clean gas pipe, or whatever is the same, between the raw gas duct and the clean gas duct.

Therefore, by choosing the smallest possible dust discharge

~ τ * 2

Opening 71 ir in relation to the radius r "of the gas inlet opening and

t> "2

the highest possible entry velocity energy <fe. u after

j S 2

the found dependency J \ p, -. r "= constant. r ^ ■ „ u der

j du s σ e

Bunker vacuum ^ Vt ₀₁₁ ) , i.e. the suction effect of the lowering flow, can be significantly increased. The speed energy increased to this level also causes an increase in the centrifugal forces on the dust particles in the zone of the dust discharge opening. As a result of this, according to the invention, there is a measurable improvement in the degree of fraction dedusting for the dust fractions in the range of

Limiting grain size and a significant reduction in feather discharge dust sucked back from the bunker. In addition, this measure enables the speed energy to be increased, independent of the absolute dimensions of the cyclone (according to the relation r. u = constant), also the determination of further most favorable proportions for a given overhead wall.

This pressure expenditure is approximately proportional for each cyclone arrangement the back pressure of the gases in the cyclone outlet cross-section and for geometrical similar cyclone dimensions essentially independent of the Size. The achievable degree of separation is here according to -Prof. Barth ("Calculation and design of cyclone separators on the basis of recent investigations", BHC, Vol. 8, 1956) mainly depending on the height

ρ ... ρ
the centrifugal forces G. ui = G. r _e . U ₀ for a given pressure

gr, g Tf .

The greater the effort, the smaller r _e and the flow cross-section Ji r ^ u. the greater: the: entry velocity level is selected.

It is therefore the assessment basis for achieving the greatest possible Degree of separation with a given pressure requirement for any size initially the general conveyance, smaller cyclones of the same dimensions and in doing so the Eadiene ratios re and r »should be chosen as small as possible, so that the deposition

rT TT *. .

up to the desired grain size limit with correspondingly high velocity energy can take place with the highest possible hopper vacuum.

The gases should enter the cyclone tangentially from above at an angle that is equal to or greater than 45 degrees, with the axial velocity component v _{e = Ug.}

Such a design of the flow paths is achieved that the rotating gases already have high centrifugal forces in the cyclone inlet cross-section and the current on its "sweep to the turnaround zone experiences relatively high axial deceleration. This delay can they. The larger the axial inlet component of the, the less follow the dust particles excreted by the centrifugal forces Speed is. The turning zone is then all the deeper.

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Figure 5 shows an embodiment for aie parallel connection of cyclone separators with the dimensional ratios required according to the invention. The sectional view shows 2 cyclone cells and their attachment within a common G-ehäuses.

The cells (2) are mounted on a supporting structure (1) and are supported by flanges (3) at the top opening of the cell _; are hearing aids (4) through which the clean gas pipes (5) lead out of the cells.

The cells are encased in a sheet metal box (6) that is connected to the Ir agkonst rule tion (1) is connected and in its lower part for the Used to collect the separated dust, laughs up close to the Coat (6) of the dust bunker of the raw gas duct (7) through a Partition wall (8) is separated from the discharging clean gas duct (9). In The clean gas pipes (5) are attached to the partition (8) in a gas-tight manner, underneath Terwandung of sealing rings (10) and wedges (11).

The cells (2) are usually made of cast iron without machining, thereby making it cheap, mass-produced, and making it resistant to wear and tear, if necessary must occur because the separated dust from the dust bunker (6) is not emptied and is in the cells (2) accumulates. Such accumulated dust wears away from the land during the strong rotation, because it will consist essentially of coarse particles, as the fine particles in the dust accumulation be taken along by the gas through the clean gas pipe (5).

If necessary, a highly wear-resistant cast iron alloy, for example hard manganese, be chosen to have higher centrifugal forces to be able to drive without wear.

The geometric proportions are shown in Figure 5 . The cyclone has a clean gas outlet radius ? ±, an average raw gas inlet radius r _e = 1.6 . The height of the cylinder area 2Tf ^ h within the cyclone, which is decisive for the separation efficiency

h = 8. r ^ and the diameter of the dust outlet opening 2r = 2rl

+) will be

Embodiment Figure 6 shows a technical drawing of a complete deduster behind a steam boiler. In it (21) denote the raw gas duct, (22) the cells of the deduster, (23) the vortex and (24) the clean gas pipes in the "partition (25) are attached, the clean gas duct (26) leads to the top. The dust collects in the dust bunkers (28), the upper part of which encases the cells in a closed box.

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Claims (4)

'■ 757560 I e u e claims 1.) MehrfaehfliehkratftentsTiauber "consisting _au; s a plurality τοη parallel Binzelzyklonen with outer Absoheiderohren (2), where the dust-containing gases are here supplied to the top by a swirl-blade ring (4) from axially and from which the purified gases in the opposite direction through the coaxial clean gas pipes (5) arranged inside the separation pipes (2) flow upwards, while the dust ejected from the flow by the centrifugal forces is conveyed through the lower dust discharge openings of the separation pipes (2) into the dust collecting bunker (6), characterized in that the The ratio of the diameter of the dust discharge opening of each cyclone (2) to the diameter of its clean gas outlet pipe (5) is as small as possible, at least less than 1/3. 2.) multiple centrifugal dust extractor according to claim 1.) characterized in that the ratio of the entry radius r _{e of} the gas flow to the radius r ^, the gas outlet opening as small as possible, in any case smaller than 1.6 is selected. 3.) Multiple centrifugal dust extractors according to one or both of the above Claims, characterized in that the pitch angle the lower ends of the helical guide surfaces of the swirl blade ring (4) equal to or greater than 45 ° is selected. 4.) Multiple centrifugal dust extractor according to one or more of the preceding claims, characterized in that the height h of the imaginary cylinder area 2- ^ r ₁ Ia within the cyclone (2), which is decisive for the separation performance, is selected as large as possible, at least equal to 8 r ^ . 3/1 November 21, 1963 "Note: This sub-suction {description and protection".) Is the last one submitted! sis soft »from the word version det origins from the documents submitted. The legal interpretation of the deviation is not checked. The originally submitted unsubscribes are in the official files. You can at any time without the need to «» legal interest can be viewed free of charge. FoWköpien -ofcr FBmnegofive Delivered at the usual prices German Patent Office, GfcbreuehsrauMente *