JPS6161867B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cyclone, and more specifically,
The present invention relates to a vertical cyclone with low pressure loss, no dust accumulation or coating, and low duct concentration in the gas discharged from the cyclone, that is, high separation efficiency.

Vertical cyclones use centrifugal force to separate and collect dust in gas, and are often used in preheating devices for cement raw materials, etc., and have the structure shown in Figures 1 and 2. ing.

That is, the conventional cyclone 1 has a cylindrical body 2 and an inverted conical hopper 3 connected to the lower end thereof, and a rectangular gas is tangentially and horizontally connected to the upper part of the cylindrical body 2. An introduction duct 4 is provided. As shown in FIG. 1, the outer wall 4a of the gas introduction duct 4 is provided so as to extend beyond the outer wall of the cylindrical body 2. Further, a gas exhaust pipe 5 is provided on the upper lid portion 2a (see FIG. 2) of the cylindrical body 2, and a dust exhaust pipe 6 is provided on the lower end of the inverted conical hopper 3.

The gas discharge pipe 5, the cylindrical body 2, the inverted conical hopper 3, and the dust discharge pipe 6 are arranged concentrically around the center axis 0, 0' of the cyclone.

Based on this structure, the gas containing dust supplied from the gas introduction duct 4 flows into the space 9 formed between the cylindrical body 2 and the gas exhaust pipe 5.
flows into the area, creating a swirling flow in this area. This swirling flow descends along the inverted conical hopper 3 while decreasing the swirling radius, thereby separating the gas and dust. The gas then changes direction upward near the lower end of the inverted conical hopper 3 and is led to the gas discharge pipe 5 through the center of the swirling flow. During this time, the dust separated and moved to the inner wall surfaces of the cylindrical body 2 and the inverted conical hopper 3 by the centrifugal force caused by the swirling flow flows down by gravity along the inner wall surfaces and is discharged from the dust discharge pipe 6.

When such a structure is adopted, since the rectangular gas introduction duct 4 is connected to the cylindrical body 2 in the horizontal plane, the gas introduction duct 4 is connected to the cylindrical body 2 in the horizontal plane, so that the
In a portion indicated by the reference numeral 2b in FIG. 1, the dust-containing gas flow flowing from the gas introduction duct 4 and the swirling gas flow inside the cyclone collide and merge in a manner substantially orthogonal to each other. As a result, the pressure loss increases and turbulence occurs in the inflowing dust-containing gas flow, and dust is entrained in this turbulent gas flow, which passes directly to the gas exhaust pipe 5 and removes the dust in the exhaust gas. The concentration increases and reduces the separation efficiency of the cyclone.

In addition, the space 9 formed by the gas exhaust pipe 5 and the side wall of the cylindrical body 2 is provided because the latter half of the cylindrical body 2 is provided concentrically with respect to the gas exhaust pipe 5. There is no big difference in the axial cross-sectional area.

Therefore, the velocity of the gas swirling in this space becomes approximately equal, making it difficult to give a minute velocity in the axial direction. As a result, the number of revolutions of gas and dust increases, the frictional resistance between the downward flow and upward flow of gas increases, pressure loss increases, and the time required for dust to flow becomes longer, inevitably remaining inside the cyclone. The amount of dust generated increases, and the dust is entrained in the gas flow rising inside the cyclone, reducing the separation efficiency of the cyclone.

The present invention has been made in order to eliminate the above-mentioned conventional drawbacks, and provides a cyclone with low pressure loss, no dust adhesion or coating inside the cyclone, and a low concentration of dust in the exhaust gas. It is intended to.

3, 4 and 5 show embodiments of the present invention. In each figure, Figures 1 and 2
The same parts as those in the figures are given the same reference numerals, and their explanations will be omitted.

In this embodiment, the upper end of the inverted conical hopper 3
A first cylindrical body 20 is disposed at the upper end 20a of the cylindrical body 20, and a first cylindrical portion eccentrically centered with the axes 0 and 0' and with the axes P and P' as the axes. 21 is provided so as to circumscribe the outer wall 4a of the rectangular gas introduction duct 4 and bulge out from the peripheral wall of the first cylindrical body 20, and has axes 0, 0', P,
A second cylindrical part 22 having the same diameter as the first cylindrical body 20 with the axis Q and Q' different from P', on the opposite side from the gas introduction duct 4, that is, in FIG. , The cylindrical body 20 is provided so as to protrude from the first cylindrical body 20 along the axis passing through the body, smoothly connecting the side walls of the first cylindrical part 21 and the second cylindrical part 22, and connecting the terminal end of the second cylindrical part 22 with the side wall of the first cylindrical part 21 and the second cylindrical part 22. A second cylindrical upper lid part 2a formed of a first cylindrical part 21 and a second cylindrical part 22 has an approximately oval shape so as to be connected to the inner wall 4b of the rectangular gas introduction duct. The dust discharge pipe 6, the inverted conical hopper 3, the first cylindrical body 20, and the second cylindrical body 23 are sequentially arranged so as to form a body 23 of the second cylindrical body. A gas exhaust pipe 5 was provided on the upper lid portion 2a of 23. Furthermore, in the plan view of FIG. 3, the peripheral wall of the second cylindrical body 23 and the peripheral wall of the first cylindrical body 20 virtually intersect, and A substantially triangular inclined flat plate 7 is provided which gradually widens from a point A on the edge 22a and descends to the upper end 20a of the first cylindrical body 20 shown in FIG. 4.

In addition, a part of the vertical side wall of the second cylindrical portion 22 that protrudes beyond the first cylindrical body 20 is formed into an inclined side wall 8 having the same inverted conical shape as the inclination of the inverted conical hopper 3. There is.

In this embodiment, the lower end of the gas exhaust pipe 5 is not inserted into the cyclone, but is attached to the upper lid 2a of the body 2.

Since the present invention is configured as described above, the dust-containing gas introduced from the gas introduction duct 4 is
The liquid flows approximately parallel to the inner wall of the second cylindrical portion 21 and reaches the protruding portion of the second cylindrical portion 22 .

During this time, the heavy dust falls onto the inner wall of the second cylindrical portion 22 due to inertial force and centrifugal force, and is separated. Since the second cylindrical portion also protrudes, the peripheral wall of the second cylindrical portion is located at a distance farther than the gas exhaust pipe 5, and therefore, the dust near the peripheral wall is less likely to escape to the gas exhaust pipe 5.

In addition, the space 9 formed between the hypothetical cylindrical part where the lower end of the gas discharge pipe 5 hangs into the cyclone and the second cylindrical part is wide, and the gas flow velocity in this part is lower than when it flows in. Therefore, the pressure loss caused by this also decreases. In addition, the dust that has descended and separated onto the peripheral wall is less likely to be re-scattering.

Furthermore, since an inverted conical side wall 8 is provided on a part of the side wall of the second cylindrical portion 22, as shown in FIG.
The gas with lower mass descends along this conical wall (indicated by the dashed arrow in the drawing), and the gas with a lower mass falls along the cone-shaped arc CD
(indicated by solid arrows in the drawing). This facilitates separation of gas and dust.

Furthermore, most of the gas separated according to the inverted conical side wall 8 flows down from point A shown in FIG. 4 along the inclined flat plate 7 formed in a substantially triangular shape.
The remaining gas flows into the second cylindrical part 22. However, since this second cylindrical portion 22 faces inward from the side wall of the first cylindrical body 20, it merges in parallel with the dust-containing gas flowing in from the gas introduction duct 4, as shown in FIG. Near orthogonal collisions and merging, such as those in conventional structures, are alleviated. Therefore, the pressure loss in this part is reduced, and the amount of the remaining gas that joins is also small, so the flow of the dust-containing gas is less likely to be disturbed, and rather, the vicinity of the gas discharge pipe 5 is covered with a clean gas flow. As a result, the dust-containing gas flow rarely passes through the gas discharge pipe 5.

The dust-containing gas that has not been completely separated at the arc CD is applied a downward force by the substantially triangular inclined flat plate 7, and is promoted to flow down along the arc DE.

Since the gas and the duct to which these downward forces are applied flow to the lower side of the gas introduction duct 4, they do not collide with the dust-containing gas flow introduced from the gas introduction duct 4 and do not disturb the gas flow. So,
There is little pressure loss and there is no reduction in dust separation.

Also, a space 9 is formed by an imaginary cylindrical part with the lower end of the gas exhaust pipe 5 hanging down into the cyclone, a second cylindrical body 23 whose upper lid part 2a is approximately elliptical, and a side wall. The swirling direction is forcibly changed by the bulging portion of the second cylindrical portion 22, the inverted conical side wall portion 8, and the approximately triangular inclined flat plate 7, and in particular, the inclined flat plate 7 changes this swirling flow. A downward minute velocity is given to the gas, reducing the number of turns, and this reduction reduces the frictional resistance due to the downward and upward flow of gas, lowering the pressure loss, and promoting the separation and discharge of dust. be done.

As a result, the amount of dust remaining in the cyclone is reduced, thereby reducing dust adhesion and coating, and the amount of dust entrained in the discharged gas is also reduced.

Next, other embodiments of the present invention are shown in FIGS. 6 and 7.
As shown in the figure. Hereinafter, the embodiment shown in FIGS. 3 to 5 will be referred to as the present embodiment, and the embodiment shown in FIGS. 6 and 7 will be referred to as the second embodiment.

The second embodiment is a second cylindrical body 2 of this embodiment.
A part of the upper lid part 2a of No. 3 projects into the cyclone.

That is, the upper lid part 2 of the second cylindrical body 23
In a, one end intersects with the outer periphery of the gas exhaust pipe 5 at point B, and the part at point B protrudes the highest,
', the width is gradually widened in a spiral shape, and the protrusion is lowered (the part shown in FIG. 6), and the protrusion is lowered so that the end of this protrusion matches the upper cover 2a of the second cylindrical body 23. protruding upper lid part 10
(BS, ST, AR, RB parts in Figure 6) are provided.

Note that S and T are points on the gas discharge pipe 5, T is on a line connecting them, and R is a point on the helical outer circumferential wall of the protruding upper lid portion 10.

With this structure, the dust-containing gas introduced from the gas introduction duct 4 is further guided to the side wall of the cylindrical body 23 by the helical outer circumferential wall BRA of the protruding upper lid part 10, and The dust that descends to the inner circumferential wall of the cylindrical body 23 due to inertial force and centrifugal force and is separated is blocked from moving to the gas exhaust pipe 5 by this protruding helical outer circumferential wall BRA. Dust escaping into the gas exhaust pipe 5 is significantly reduced.

Furthermore, this protruding helical outer peripheral wall BRA
This facilitates the guidance of gas and dust to the portion formed by the substantially triangular inclined flat plate 7 and the inverted conical side wall 8, thereby further
It reduces the number of rotations and promotes the descent of dust, resulting in a remarkable effect in reducing pressure loss and increasing dust collection efficiency.

FIGS. 8a and 8b show the dust collection efficiency and pressure loss with respect to the mixing ratio according to this embodiment of the present invention.

The results of this embodiment of the present invention are represented by a solid line, and the results of the conventional cyclone are represented by a dashed line.

In this comparison, it is clear that the effect of this example is superior to the conventional one.

As is clear from the above description, according to the present invention, the second cylindrical body 23 bulges closer to the gas introduction duct than the first cylindrical body 20, and is in circumscribed contact with the first cylindrical body 20. It also bulges on the opposite side of the introduction duct, and part of the side wall of this bulge has an inverted conical sidewall, so gas and dust are quickly separated and the swirling flow rate is also reduced. Therefore, the pressure loss is reduced and the separated dust is less likely to be stirred up again.

Furthermore, by providing the approximately triangular inclined flat plate 7 between the second cylindrical body 23 and the first cylindrical body 20, the gas and dust flowing into this portion are directed downward at a rate of is forcibly applied, thereby reducing the number of rotations of the gas flow, lowering the pressure loss, and promoting the descent and discharge of dust. Furthermore, the gas flow is divided into a downward flow and a circumferential flow by the substantially triangular inclined flat plate 7, and collisions and merging at right angles with the dust-containing gas flow flowing from the gas introduction duct are alleviated. It also has a remarkable effect on reducing pressure loss and improving dust collection efficiency.

Furthermore, since the circumferential flow is a relatively clean gas flow from which most of the dust has already been separated, this clean gas covers the circumference of the gas exhaust pipe, causing the dust to escape into the gas exhaust pipe 5. prevent it from dispersing.

This is clear from the fact that good results can be obtained even without inserting the lower part of the gas discharge pipe 5 into the cyclone, as described in this embodiment.

In addition, as explained in the second embodiment (shown in FIGS. 6 and 7), by providing the protruding upper lid portion 10, gas and dust can be prevented on the upper surface of the second cylindrical body 23. This not only significantly increases the separation efficiency but also helps guide the dust-containing gas to the space formed between the inclined side wall 8 of the bulging portion of the side wall of the cylindrical body 23 and the substantially triangular inclined flat plate 7. hand,
This can have a great effect on lowering pressure loss by lowering and separating dust and reducing the number of turns.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the structure of a conventional cyclone, Fig. 2 is a front view of Fig. 1, Fig. 3 is a plan view showing the structure of the present embodiment of the present invention, and Fig. 4 is the same as Fig. 3. 5 is a side view of FIG. 4, FIG. 6 is a plan view showing the structure of another embodiment of the present invention, FIG. 7 is a front view of FIG. 6, and FIGS. 8a and 8b are This figure shows the experimental results of the cyclone of this embodiment of the present invention and a conventional cyclone, where a is a diagram showing the dust collection (separation) efficiency versus the mixing ratio, and b is a diagram showing the pressure loss versus the mixing ratio. FIG. 1 is a cyclone, 2 is a fuselage, 2a is an upper lid of the fuselage, 2b is a gas confluence near the connection between the gas introduction duct and the spiral fuselage, 3 is an inverted conical hopper, and 3a is the lower end of the cylindrical fuselage. and the upper end of the inverted conical hopper, 4 is a gas introduction duct, 5 is a gas discharge pipe, 6 is a dust discharge pipe, 7 is an inclined flat plate, 8
9 is a space formed between the cylindrical body and the gas discharge pipe; 10 is a protruding upper lid; 20 is a first cylindrical body; 20a
is the upper end of the first cylindrical body; 21 is the first cylindrical portion; 22 is the second cylindrical portion; 22a is the upper edge of the second cylindrical body; 23 is the second cylindrical body; The body, A is a point on the upper edge of the second cylindrical body where the circumferential wall of the first cylindrical body and the circumferential wall of the second cylindrical body virtually intersect, and B is the point on the upper edge of the protruding upper lid. This is the highest point.

Claims (1)

[Claims] 1. An inverted conical hopper is formed in the lower part, a dust discharge pipe is formed at the lower end of the inverted conical hopper, and a cylindrical body is disposed continuously at the upper end of the inverted conical hopper. In a cyclone in which a gas introduction duct for introducing dust-containing gas from the tangential direction or circumferential direction is provided in the body, and a gas discharge pipe is provided in the upper lid of the cylindrical body, the cylindrical body has a first duct with different axes. Consisting of a cylindrical body and a second cylindrical body,
The first cylindrical body is coaxial with the inverted conical hopper, and is provided continuously at the upper end of the inverted conical hopper. The second cylindrical body smoothly circumscribes the outer wall of the gas introduction duct.
A cyclone comprising a cylindrical part and a second cylindrical part having the same diameter as the first cylindrical body and protruding on the opposite side from the gas introduction duct. 2 A protruding upper lid part that protrudes into the cyclone is provided in a part of the upper lid part of the second cylindrical body,
One end of the protruding upper lid is the highest in contact with the outer peripheral wall of the gas discharge pipe, and the other end is inclined asymptotically to the upper surface of the upper lid, so that the outer peripheral wall of the protruding upper lid has a helical shape. A cyclone according to claim 1.