JPS60161761A - Cyclone - Google Patents

Abstract

PURPOSE:To attain to reduce pressure loss and to enhance dust collection efficiency, by forming the introduction part of a cyclone inlet duct into a cyclone into a curved shape. CONSTITUTION:The introduction part of a cyclone inlet duct into a cyclone is formed into a curved shape. In this introduction part, raw particles are flocculated by the action of centrifugal force and the stay time of particles in a centrifugal field becomes long and high dust collection efficiency is obtained. Therefore, the speed of inlet gas is suppressed low and pressure loss is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in cyclones, particularly cyclones used in cement firing kilns with suspension preheaters.

Conventionally, cyclones such as those shown in Figs. 1 to 4 have been used in suspension preheaters. However, these conventional cyclones had the following drawbacks because the introduction portion into the cyclone was linear.

(1) Cyclone pressure loss is 100 to 50 m
Aq is large.

(2) The dust collection efficiency of the cyclone is low at 60-70%.

Horizontal cyclones and vertical axial flow cyclones are being proposed and adopted as a measure to eliminate the drawback of (1) above, but looking at the data when using these new cyclones, the dust collection efficiency is lower than that of the conventional cyclones although the pressure loss is reduced. Although it has a lower heat consumption unit than that of a conventional cyclone, it is not necessarily satisfactory. For example, there is a lot of data showing that the heat unit of a cement firing process in which a four-stage cyclone preheater is modified to a five-stage preheater with two horizontal cyclones attached is higher than that of a normal rotary kiln with a four-stage cyclone preheater. This phenomenon is caused by the poor dust collection efficiency of the horizontal cyclone, and shows that consideration was not given to the cyclone dust collection efficiency.

The present invention aims to provide a cyclone with low pressure loss and high dust collection efficiency. That is, the gist of the present invention is
The cyclone is characterized in that the introduction portion of the cyclone inlet duct into the Signron is formed in a curved shape.

The present invention will be explained below based on the drawings.

FIG. 1 is an example of a conventional cyclone, and shows a conceptual plan view of a tangential flow type cyclone. FIG. 2 shows a longitudinal sectional view of the cyclone shown in FIG. 1. In the figure, 1 is the cyclone cylinder part, 2
6 shows the cyclone cylinder, 6 shows the cyclone introduction part, 4 shows the cone part, and 5 shows the rising side duct from the lower cyclone.

Figure 6 shows another example of a conventional cyclone, which is usually called a Linden-type cyclone, with the cyclone introduction part placed slightly outside compared to the one in Figure 1.

It is something that FIG. 4 is a view taken along the line A--A in FIG. 3.

Note that the numbers in the figure are the same as in FIG. 1.

In the cyclones shown in Figs. 1 and 6, the introduction section 6 is linear, so the gas flows into the cyclone in an almost straight flow.
It rotates along the wall, and the raw material particles are separated from the gas by the centrifugal force caused by the rotation. However, because the residence time of the particles in the centrifugal field is short, the dust collection efficiency is low at 60 to 70%, so the dust collection efficiency is improved. For this, the cyclone inlet gas velocity “k
20-25 rn/'sec (normal) to 30 m/
sec, which inevitably increased the pressure loss of this cyclone.

Figures 5 and 6 show examples of the present invention, in which the introduction section 3 into the cyclone is curved, so that the raw material particles are agglomerated due to the action of centrifugal force in this section as well. Since the residence time of particles in the field is long, high dust collection efficiency can be obtained. Furthermore, because the dust collection efficiency is high, the inlet gas velocity of the cyclone has been reduced from the conventional 20 to 30 m/sec to 1.
The pressure loss can be reduced to about 5 m/sec.

In this way, even with a low cyclone inlet gas velocity, much higher dust collection efficiency can be achieved than with conventional cyclones.

In this invention, the cyclone introduction section refers to the duct section in front of the cyclone opening.

Further, the introduction portion may be curved by connecting polygons.

Example 150 An example in which the cyclone of the present invention shown in Fig. 6 was applied to a t/h SP kiln, and a conventional cyclone shown in Fig. 3 and a cyclone with an enlarged inlet of the conventional cyclone shown in Fig. 6 were used. Table 1 shows an example of an experiment conducted using the following methods.

Table 1 From the results shown in Table 1, it can be seen that the conventional cyclone was unable to simultaneously satisfy both high dust collection efficiency and low pressure loss, but the cyclone of the present invention was able to satisfy both of these at the same time.

[Brief explanation of drawings]

Figures 1 and 6 are conventional cyclones, Figure 2 is a cross-sectional view of M in Figure 1, Figure 4 is a view along arrow A-A in Figure 3, Figure 5,
FIG. 6 shows an embodiment of the cyclone of the present invention. 1...Cyclone cylinder part 2...Cyclone inner cylinder 5
... Cyclone introduction section 4 ... Cyclone cone section 5 ... Rise duct from lower cyclone Patent applicant: Nippon Cement Co., Ltd. Agent Patent attorney Akira Ito Procedural amendment dated 3rd January, 1980, Patent Office Chief Justice Kazuo Wakasugi 1, Narrow indication of the case 1982 patent application 16oot No. 2, name of the invention Cyclone 3, person making the amendment Indication of the case Patent applicant address 1-6-1 Otemachi, Chiyoda-ku, Tokyo Name Japan Cement Co., Ltd. Representative Toru Kitaoka 4, Agent 101 Address 2-42-5 Kanda Jimbocho, Chiyoda-ku, Tokyo
Application and specification to be amended (typed copy) 6. Contents of amendment Attachment 9

Claims (1)

[Claims] A cyclone characterized in that the introduction part of the cyclone inlet duct into the cyclone is formed in a curved shape.