CN216726212U - Cyclone separator with adjustable particle bypass - Google Patents

Abstract

The utility model relates to a cyclone separator (10) with adjustable particle bypass, comprising a body with a cylindrical area and at least one bypass duct (20) arranged to guide particles to a cyclone discharge duct (30), the bypass duct (20) comprising a replaceable short tube portion (40). According to the utility model, the efficiency of the cyclone separator is easily adjusted and the service life of the bypass pipe is longer.

Description

Cyclone separator with adjustable particle bypass

Technical Field

The present application relates to a cyclonic separator comprising a body having a cylindrical region and at least one bypass duct arranged to direct particles to a cyclonic discharge duct.

Background

Traditionally, the first stage in blast furnace off-gas dedusting is a dust separator. It is simply a large vessel with a low gas velocity, allowing coarse dust particles to fall out of it. The second stage is a wet scrubber, where smaller particles are removed. Due to its composition, the dust captured in the dust separator can be recycled back to the blast furnace. Dust captured in wet systems must be handled in other ways because it contains unrecoverable materials such as zinc.

Dust separators do not always achieve the desired separation and many recyclable materials enter the wet system with the contaminants. There is a need for a more efficient dedusting system that maximizes the recovery of good materials while diverting contaminants to the wet system.

Another conventional dry dust collector is a cyclone separator. Unfortunately, the efficiency of the cyclone separator is often high enough to collect the excess zinc-containing material.

It is not simple to design a cyclone separator in order to achieve a reduced efficiency. Typically, the dusty gas inlet conditions are not accurately known or may change during operation. The necessary efficiency may be unknown and may vary depending on changes in the size distribution of the dust particles. During test work it has been found that changing the geometry of the cyclone separator does not always produce the desired change in dust collection efficiency. The efficiency of the cyclone separator can be varied during the design stage by reducing the inlet velocity. The effect of this would be to increase the size of the cyclone separator, which in turn increases the cost. The result will be that the performance of the cyclone will still be subject to variations in inlet conditions and dust loading as well as particle size analysis.

Traditionally, the dusty gas from a blast furnace is sent to a first stage cleaning plant via a pipe called a downcomer, which is very sloped, typically at an angle between 40 and 55 degrees depending on the site layout. The inlet to the cyclone is in a horizontal plane and rectangular in cross-section. In order to turn the airflow towards the horizontal plane, designers may consider using internal guide vanes, typically of rectangular cross-section, to improve the flow distribution into the cyclone.

An example of such a cyclone is shown in WO2008099214a 1. It is known from WO2008099214a1 to provide a bypass arrangement which allows the efficiency of the cyclone to be adjusted. In the arrangement shown in WO2008099214a1, the adjustment can be made by opening a different number of bypasses-opening two bypasses, less material will pass than if 4 bypasses were opened, and therefore the cyclone separator will be more efficient in the first case. As mentioned above, the higher efficiency of the cyclone may result in more unrecoverable material being captured by the cyclone, which is an undesirable effect.

SUMMERY OF THE UTILITY MODEL

Technical problem

The object of the utility model is to provide a solution which allows easy adjustment of the cyclone efficiency and longer life of the bypass duct.

Solution scheme

The proposed solution to achieve an easy adjustment of the efficiency of the cyclone separator involves:

a cyclone separator comprising:

a body having a cylindrical region and at least one bypass duct arranged to direct particles to the cyclonic discharge duct, the bypass duct including a replaceable pipe section portion.

The present invention relates to a cyclone separator having an inlet (via an inlet duct) and a small particle bypass arrangement allowing to adjust the efficiency of the cyclone separator during furnace shutdown or to optimize capture of recyclable material while transferring contaminants to a wet cleaning system.

The inlet may be a classifier inlet, the term "classifier inlet" meaning an inlet where the particles are distributed according to their size. Generally, larger particles will be more concentrated in the lower region of the classifier inlet.

The use of multiple bypasses currently known to be opened or closed depending on the desired cyclone efficiency (as discussed for example in WO2008099214a 1) may be problematic due to wear and blockage caused by process properties, the bypass tubes have a relatively small cross-sectional area for gas flow relative to the inlet ducts, so closed tubes are prone to blockage, and the higher velocity in these small diameter bypass tubes may lead to wear and ultimately to material failure. In the currently used plants, replacing worn or blocked/worn bypass tubes directly constrains furnace production.

Effect of the utility model

A bypass conduit is provided comprising replaceable pipe section parts, which makes replacement and handling easier in short shut-downs, as a result of the mounting of another replaceable pipe section part to counteract wear and/or clogging.

If one replaceable segment portion can be replaced with another replaceable segment portion having a larger or smaller airflow cross-sectional area, the efficiency of the cyclone separator can be readily adjusted by selecting the appropriate airflow internal cross-sectional area of the replacement segment portion to achieve the desired efficiency. Thus, the small particle bypass becomes easily adjustable.

In another preferred embodiment, the replaceable pipe segment portion includes an outer envelope and an inner insert secured to the outer envelope. The inner insert being fixed to the outer envelope means that the inner insert is not interchangeable. When using a replaceable pipe section according to this embodiment, the operator will have a plurality of replaceable pipe sections with different internal diameters for him, and during short downtimes, simply select one from these stocks to replace according to his requirements. Therefore, the replacement is very easy and takes little time.

In another preferred embodiment, the replaceable pipe segment portion includes an outer envelope and an interchangeable insert. Thus, the outer envelope may be used with different interposers. Therefore, if an insert having a different internal cross-sectional airflow area is used, the change in the internal cross-sectional airflow area of the replaceable pipe section portion can be easily accomplished. This makes it easy to adjust the efficiency of the cyclone separator, while the outer envelope is reused, thereby keeping costs down. Preferably, a plurality of inserts with different internal diameters will be provided to enable the desired diameter to be quickly and easily obtained, resulting in suitable replaceable pipe segment portions.

Compared with the traditional bypass, the method has the following advantages: in the conventional use of several bypass ducts that are opened or closed on demand, the need for low cyclone efficiency results in a large number of bypass ducts being opened to provide a wider passage for the airflow — the sum of the cross-sectional areas of the open bypass ducts is available for the airflow. In practice, the gas flow must be forced into several parallel bypass ducts, each of which has a limited cross-sectional area. In the proposed solution, if there is only one bypass providing a cross-sectional area equal to the sum of the cross-sectional areas, the risk of clogging and wear due to lower gas velocities is reduced. Furthermore, refurbishment of worn bypass ducts is made easier by using replaceable duct section elements. In these replaceable pipe section elements, it is easier to install special wear resistant material on the pipe section than to install the bypass without the replaceable pipe section elements.

Preferably, the cyclonic separator has an inlet duct, wherein the inlet duct comprises an inclined region, a bend and a region which enters the body tangentially to the cylindrical region. As described in WO208099214a1, the cyclone separator may employ an inlet bend without vanes which enters the cyclone separator tangentially and acts as a coarse classifier, thereby promoting the accumulation of larger dust particles in the lower portion of the inlet duct. Preferably, the cyclonic separator has an inlet duct, wherein the inlet duct is inclined and enters the cyclonic separator substantially at right angles to the radius of the cylindrical region. The downcomer may enter the cyclone directly, generally at right angles to the radius of the cylindrical region of the body and without a bend. The classification effect is transferred to the top of the cyclone body, where smaller dust particles are removed via the bypass duct. In another embodiment, the cyclonic separator has an inlet duct, wherein the inlet duct enters the main body horizontally. The classification effect of the dusty gas stream in the horizontal duct is utilised which is not as strong as that shown by the curved or inclined inlet, but it can still be used in a similar manner, with the bypass duct mounted at the top of the cyclone body as described above.

Drawings

The present invention will now be described with reference to fig. 1, 2, 3, 4, 5, which schematically illustrate aspects of the utility model.

Figure 1 shows an enlarged cross-section of the upper part of the cyclone separator.

Fig. 2 shows an exploded view of the bypass of fig. 1.

Figures 3, 4, 5 show further variants of the cyclonic separator apparatus.

Detailed Description

Examples of the utility model

Referring to fig. 1, an enlarged cross-section of the upper portion of the cyclone separator 10 is shown. The cyclonic separator 10 comprises a body having a cylindrical region which is not shown in detail for clarity of the drawing as it is well known in the art. A bypass duct 20 is arranged to direct particles to the cyclonic discharge duct 30, the bypass duct 20 including a replaceable pipe section portion 40. In the depicted variant, the replaceable pipe section 40 of the bypass pipeline 20 is connected to another pipe section of the bypass pipeline 20 by an expansion joint 50, thereby facilitating installation and removal.

Referring to fig. 2, an exploded view of the bypass 20 of fig. 1 is presented. Within the outer envelope 60 of the replaceable pipe segment portion 40, there is an insert 70. Insert 70 may be interchangeably secured to outer package 60.

Referring to fig. 3, the cyclonic separator 80 is shown as having a substantially cylindrical main body 90 and further comprising an inlet duct 100 having an inclined region 110 and having a region 120, the region 120 entering the main body 90 tangentially by means of a bend 130. The bend 130 tends to decelerate the particles so that larger particles tend to move toward the bottom of the inlet conduit, but smaller particles are less affected by the bend and remain generally uniformly distributed. The larger dust particles are collected by the cyclone 80 in the normal manner. A portion of the smaller particles containing a high proportion of contaminants near the top of the inlet duct 100 is diverted from the upper end of the cyclone body 90 into the cyclone discharge duct 150 via a bypass 140 according to the utility model, which bypass 140 is not depicted in detail for the sake of clarity of the drawing. The number and/or inner diameter size of the bypass ducts employed depends on how much of the gas flow needs to be diverted. Preferably with only one bypass.

Referring to fig. 4, the inlet duct 160 is inclined and enters the cyclone separator 170 at right angles to the radius of the cyclone separator 170. Also, the particle classification effect means that smaller particles are preferentially diverted through the bypass conduit 180.

Referring to fig. 5, the inlet duct 190 is horizontal. Even in this simple arrangement, the classification effect means that smaller particles are preferentially transferred via the bypass conduit 200 to the discharge conduit 210.

The bypass may be provided with means for isolation, such as a valve or closure plate. The decision whether to open or close the bypass is made based on the measurement of the zinc content of the collected cyclone dust.

List of reference numerals

10 cyclone separator

20 bypass conduit

30 discharge conduit

40 pipe segment part

50 expansion joint

60 encapsulation

70 interposer

80 cyclone separator

90 main body

100 inlet duct

110 inclined area

120 region

130 bending part

140 bypass

150 discharge conduit

160 inlet conduit

170 cyclone separator

180 bypass conduit

190 inlet duct

200 bypass conduit

210 discharge conduit

List of cited documents

Patent document

WO2008099214A1。

Claims (6)

1. A cyclone separator, characterized in that it comprises a body having a cylindrical area and at least one bypass duct (20) arranged to guide particles to a cyclone discharge duct (30), said bypass duct (20) comprising a replaceable pipe section portion (40).

2. The cyclone separator according to claim 1, wherein the replaceable tube segment portion (40) comprises an outer envelope (60) and an inner insert (70) fixed to the outer envelope (60).

3. The cyclone separator according to claim 1, wherein the replaceable tube segment portion (40) comprises an outer envelope (60) and an interchangeable inner insert (70).

4. The cyclone separator according to any one of claims 1 to 3, characterized in that it has an inlet duct, wherein the inlet duct comprises an inclined area (110), a bend (130) and an area entering the body (90) tangentially to the cylindrical area.

5. The cyclone separator of any one of claims 1 to 3, wherein the cyclone separator has an inlet conduit, wherein the inlet conduit is inclined and enters the cyclone separator at right angles to the radius of the cylindrical region.

6. The cyclone separator of any one of claims 1 to 3, wherein the cyclone separator has an inlet duct, wherein the inlet duct enters the body horizontally.

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