JPS6026295Y2 - Heat exchange unit between powder and gas - Google Patents

Description

[Detailed description of the invention] This invention relates to the structure of a heat exchange unit between powder and gas, and in particular, by reducing the ventilation pressure loss of the gas while maintaining a high separation exchange rate, it is possible to efficiently exchange heat. This is what I did.

Preheating cement raw material powder, aluminum hydroxide powder, etc.
Alternatively, when cooling combusted alumina, etc., these powders and granules may be thrown into rising gas, and the powders and granules may be heated or cooled by heat exchange without being entrained in the gas.

The powder and granules introduced into the gas must be separated from the gas after heat exchange, and a cyclone separator is often used as the separation means.

FIG. 1 is a diagrammatic system diagram showing the steps of preheating, calcining, firing, and cooling cement raw material powder. In the figure, solid arrows indicate the flow of hot air, and dashed arrows indicate the flow of the raw material powder.

The outline of the device consists of a raw material preheating device 1, a calcining furnace 2, a calcining furnace 3 such as a rotary kiln, and a clinker cooler 4, and the cement raw material powder supplied from the raw material input chute 5 is The cyclone separators C1 to C3 are sequentially lowered, and the high-temperature exhaust gas from the firing furnace 3 and the calcining furnace 2 is sucked by the induced draft fan 7 and rises inside the raw material preheating device 1. C1~
Inside C3, heat exchange between the raw material powder and the high temperature gas is repeated.

The preheated raw material powder is discharged from the second stage cyclone separator C3 from the bottom in the raw material preheating device 1, and is passed through the chute 9.
It is introduced into the calcining furnace 2 through the calcination furnace 2.

On the other hand, combustion occurs in the calciner 2 using high-temperature secondary combustion air introduced from the clinker cooler 4 and fuel supplied together with the primary combustion air from the burner 6, and the combustion heat and the combustion furnace exhaust gas are combined. The raw material powder is calcined by receiving sensible heat.

The calcined raw material powder enters the lowermost cyclone separation '4Cq from the calciner 2 together with the combustion gas and is separated, then enters the calciner 3 through a chute and is supplied from the burner 6a installed at the lower side of the calciner 3. The fuel is subjected to necessary heat treatment in the kiln 3 to become clinker, and then cooled in the cooler 4.

The air for cooling the clinker is supplied by a forced air blower 10, and a part of the air heated by heat exchange with the clinker is distributed to the calcining furnace 2 and the calcining furnace 3, or the excess air is supplied by induced draft. It is discharged by machine 11.

The clinker discharged from the clinker cooler 4 is then conveyed to the next process by a conveyor 12.

The most common configuration of the cyclone separator used in such heat exchange equipment is shown in Figure 2 (partially cutaway diagram), in which gas is introduced almost horizontally, and gas is introduced almost horizontally. The cyclone is rotated and lowered along the inner wall of the separator, reversed at the bottom of the cyclone, and then the center of the cyclone is rotated upward and discharged vertically, resulting in an extremely large pressure loss and a high rate of gas delivery. The strong swirling flow generated in the Zylon separator remains in the side duct, and the duct rises up in a relatively long, almost vertical shape, then bends almost horizontally and flows into the upper cyclone separator. Since it is connected, there is also a large pressure loss here.

Therefore, as the ventilator 7 provided in such a heat exchange device, an induced ventilator with a high suction pressure is required, and power consumption also increases.

Furthermore, since the cyclone separator is tall, the entire device becomes large and the equipment costs are high.

For these reasons, there is a desire to develop separation means and devices that have low pressure loss and low equipment and operating costs.

The applicant has previously invented a method and device for heat exchange between powder and gas that satisfies these requirements, and has filed a patent application.

The method is to form a spiral duct whose center axis is almost horizontal in a part of the duct that guides the gas upward, and to supply powder and granules to the inlet side duct and swirl it. The heat-exchanged powder and granules were taken out from the lower end of the tube.

By the way, regarding such a new type of horizontal type cyclone, an invention is known, for example, as disclosed in Japanese Patent Application Laid-open No. 79061/1983.

The invention relates to a cylindrical body having a horizontal axis [the first aspect of the present invention to be described later].
This is an improved version of the cone (corresponding to the powder discharge chute of the present invention) formed at the bottom of the separation chamber.

In the present invention, a part corresponding to the second separation chamber portion of the present invention is not provided, and the gas separated by the cylinder is directly guided upward via the outlet duct.

That is, in the disclosed invention, it is necessary to enhance the separation effect in the cylinder corresponding to the first separation chamber portion, and the inside of the cone is divided by partition plates and a collection guide plate is provided to forcefully remove the powder and granules. This is an extremely complicated process in which the powder and granules that cannot be separated are prevented from entering the space due to force, by separating the particles and installing a rotation guide plate to swirl only the gas while providing a collision plate. structure is adopted.

Putting aside a direct evaluation of the disclosed invention, considering the background of the invention, in the past there was only a cylindrical body corresponding to the first separation chamber, so powder and granules could not be separated completely in this chamber. It is clear that there was a problem with the air flowing upwards through the exit duct.

In other words, this does not mean that the function as a separation cyclone is fully demonstrated.

Against this background, the present inventor conducted various studies and proceeded with research in the direction of enhancing the separation function of the above-mentioned horizontal or lateral cyclone.

At this point, the research direction was divided into two main directions.

The first is to improve the separation efficiency in the cylindrical body portion described in the published invention, and the first separation chamber of the present invention has been improved from this standpoint, and the separation efficiency has been improved through structural improvements. We are trying to improve.

The second direction is to supplementally provide a second separation structure, and the second separation chamber supplementarily described in this specification is an example of this.

However, the first separation chamber of the present invention provides an excellent separation function as a first separation chamber regardless of the presence or absence of the second separation chamber or its configuration.

However, the present invention, which focuses on such a first separation chamber portion, is a first cylindrical body having a substantially horizontal axis and having a closed end face on the gas introduction side and an open end face on the gas discharge side; A second cylindrical body that has a smaller diameter than the cylindrical body and is arranged substantially concentrically, and has an open end face on the gas inlet side and a closed end face on the gas outlet side; an introduction duct that connects to the lower heat exchange device or guides rising gas from the outside, a powder supply chute that supplies powder and granule from the upper heat exchange device to the introduction duct, and a first cylindrical body. a second separation chamber which surrounds the opposing parts of the gas discharge side open end of the second cylindrical body and the gas introduction side open end of the second cylindrical body and has a lower heat exchanger or a powder discharge chute to the outside connected to the lower side; The exhaust duct is connected to the gas exhaust side end of the cylindrical body in the circumferential direction or tangential direction and guides the gas upward to the upper heat exchange device.

The present invention will be explained in detail below based on the drawings. However, the drawings show an example of the concrete implementation of the present invention, and the present invention is not limited to these illustrated examples, but may include some parts in accordance with the spirit of the above and below. The same implementation is possible even if the configuration of or a part of the design is changed.

In particular, in the following explanation, the second separation chamber portion will also be described to help understand the invention.

Fig. 3 is a side view of a powder preheating device configured by combining the heat exchange units 13 of the present invention in three stages, Fig. 4 is a right side view of Fig. 3, and Fig. 5 is a plan view of Fig. 4. So, the unit 1
3 can be configured by connecting an appropriate number to each other as necessary.

When used as the powder preheating device 1 shown in FIG. 1, it is desirable to prevent the powder from flowing out of the system, so a cyclone separator C1 is combined on the top stage. Although the heat exchange unit 13 is illustrated in the figure, the present invention is an illusion of the heat exchange unit 13, and the number of combinations and the assembly of these units are free to make design changes such as connecting and configuring other heat exchange devices or separation devices. can be done.

FIG. 6 is a partially cutaway side view of the heat exchange unit 13 according to the present invention, showing an enlarged view of the unit 12 provided in the middle part of FIG. 4.

7 is a partially cutaway side view seen from the right side of FIG. 6, and FIG. 8 is a partially cutaway side view seen from the left side of FIG. 6. As shown in these figures, the embodiment of the present invention is The unit 13 has a gas introduction duct 14 connected circumferentially or tangentially to one end side of a first cylindrical body 15 whose axis is arranged substantially horizontally, and an end face 15 of the first cylindrical body 15 on the gas introduction duct 14 side.
Close b.

The carrier side is left open as a gas exhaust side.

The open end 15a side of the first cylindrical body 15 is connected to one side of a casing 19 whose diameter is larger than the outer diameter of the first cylindrical body 15, and the open end 15a is made to protrude into the casing 19. A first separation chamber 19a is formed within the housing 19.

Further, a second cylindrical body 17 that is concentric with the first cylindrical body 15 and has a smaller diameter than the inner diameter of the cylindrical body 15 is attached to the other side of the housing 19, and an open end on the gas introduction side of the second cylindrical body 17 is attached. 17a is made to protrude into the first separation chamber 19a.

A gas exhaust duct 16 is provided at the other end of the second cylindrical body 17.
are connected in the circumferential direction or tangential direction, and the end surface 17b of the second cylindrical body 17 on the side of the gas discharge duct 16 is closed, thereby forming a second separation chamber 23 at the end of the second cylindrical body 17 on the gas discharge side.

However, as mentioned above, the presence or absence of the second separation chamber 23 and its configuration do not limit the present invention.

On the other hand, the lower side of the casing 19 constituting the first separation chamber 19a is narrowed and extended downward as shown in the figure to form a part for separating the powder and granules and connect the outlet chute 20 for the powder and granules J-1.

Further, a hopper part 21 formed in the same manner as the separation part is provided on the lower side of the second separation chamber 23, and a powder discharge chute 22 is connected to the lower part of the hopper part 21.

It is recommended to provide a re-scattering prevention plate 25 (see FIG. 9) for separating powder and granules on the lower side of the first separation chamber 19a.

7. The powder and granular material is introduced from the supply chute 13 connected to a part of the gas introduction duct 14 connected to the first cylindrical body 15, and the gas discharge duct 16 is disposed at the upper side of the heat exchanger of the present invention. It is connected to the unit 13 or other heat exchange device, and the duct 16 has an opening 24a for supplying powder or granules as necessary.
is formed.

Further, the powder discharge chutes 20 and 22 connected to the first separation chamber 19a and the second separation chamber 23 are each provided with a gate valve, for example, as shown in FIG. It is connected to the powder supply chute 18 which is connected to the introduction tact 14.

In the heat exchange unit 13 configured in this manner, gas is removed from the gas introduction duct 14 by a suction device connected to the gas discharge duct 16, as shown in FIG. be introduced.

Then, the gas moves in a spiral manner to the open end side of the cylindrical body 15 while swirling in the direction of arrow A within the first cylindrical body 15, accompanied by the powder and granules introduced from the supply chute 18, and during this time, After heat exchange with the granular material, a part of the granular material is separated into the first separation chamber 19a by centrifugal force and discharged from the discharge chute 20.

Further, the powder and granules that were not completely separated in the first separation chamber 19a are moved in a spiral manner inside the second cylindrical body 17, and moved in a second separation chamber 23 formed at the gas discharge side end by centrifugal force. The gas is separated and discharged from the discharge chute 22, and the gas after separating the powder and granules is discharged from the discharge duct 16.

In such a heat exchange process, the introduced gas flows into each cylindrical body 15.
．． Only a unidirectional swirling flow is formed within the cyclone separator 17, and there is no reverse flow like in the cyclone separator described above, so pressure loss is extremely small.

Furthermore, no swirling flow in the cross-sectional direction of the ducts is formed in the gas introduction duct 14 and the discharge duct 16, and since these ducts can be connected with straight upright ducts as shown in Figures 3 and 4, there is no pressure loss due to bends. .

Furthermore, since the heat exchange unit can be made smaller and the length of the duct can be shortened, the equipment volume can be reduced and equipment costs can be kept low.

Further, in particular, in this embodiment, the separation chamber is composed of two stages, the first separation chamber 19a and the second separation chamber 23, so that the separation efficiency is extremely high.

Furthermore, when used as a heat exchange unit between powder and gas, the concentration of the powder is usually high, so the powder behaves more as an aggregate than as a single particle, resulting in a centrifugal separation effect. is enhanced.

In addition, in the illustrated example, there is a second separation chamber 23 on the lower side of the discharge duct 16.
Therefore, the supply chute 2 as shown in Fig. 4 is formed.
Even if the powder and granules that are introduced from 4 and are to be supplied to the upper heat exchange unit cannot ride the introduced gas flow, they can be discharged from the second separation chamber 23 by gravity. There are advantages such as preventing abnormal accumulation of powder and granules inside the heat exchange unit.

In the illustrated example (FIG. 6), the open end 15a of the first cylindrical body 15
and the open end 17a of the second cylindrical body 17 have been shown to protrude into the first separation chamber 19a at a constant distance, but as shown in FIG. The end 17a may be plunged into the first cylindrical body 15, or the first
As shown in FIG. 1, only the open end 17a side of the second cylindrical body 17 may protrude into the first separation chamber 19a, and the open end i5a of the first cylindrical body 15 may be aligned with the inner surface of the side wall of the housing 19. However, by configuring the second cylindrical body 17 to have a smaller diameter than the first cylindrical body 15, and by configuring the gas introduction side end 17a of the second cylindrical body 17 to protrude into the first separation chamber 19a, high separation efficiency can be achieved. Obtainable.

In addition, regarding the re-scattering prevention plate 25 installed in the separation chamber, the first
Although the one provided in the separation chamber 19a is shown, it can be similarly provided in the second separation chamber 23, and these can be freely selected such as a fixed type or a movable type, and their shape can also be changed appropriately.

Furthermore, although the first cylindrical body 15 and the second cylindrical body 17 are shown to be completely open-core, the center of the second cylindrical body 17 is eccentrically positioned above the center of the first cylindrical body 15 as shown in FIG. Alternatively, the lengths of the open ends 15a and 17a of the cylindrical body protruding into the first separation chamber 19a can be freely designed.

In short, the present invention can be satisfied as long as they are substantially concentric.

Furthermore, when designing the length of each cylindrical body, cylindrical body 15.
Separation efficiency can be maximized by designing so that the main stream of the swirling flow flowing inside the first separation chamber 19a passes near the bottom of the ship's gear at the position of the first separation chamber 19a.

With this in mind, the cylindrical protruding portions may be made slidable so that the open end positions thereof can be adjusted relative to each other.

Furthermore, if necessary, the heat exchange unit may be constructed by lining the inside with a fireproof heat insulating material or by constructing a heat insulating material on the outside, and manholes, inspection holes, and cleaning holes may be provided at appropriate locations.

In addition, when this heat exchange unit is used to cool powder or granular materials, the gas supplied from the outside to the gas introduction duct is mixed with cooling gas from the lower chutes of the first and second separation chambers. It can be configured to discharge the powder and granular material to the outside.

Since the heat exchange unit for granular material and gas according to the present invention is configured in this manner, extremely high separation efficiency and heat exchange efficiency can be obtained in the first separation chamber portion.

Further, it is possible to create a small and inexpensive facility with little pressure loss, and also to provide a heat exchange unit that is easy to operate, maintain and manage.

[Brief explanation of drawings]

Fig. 1 is a diagrammatic system diagram of the steps of preheating, calcining, firing, and cooling cement raw material powder, Fig. 2 is a partially broken diagram of a cyclone separator, and Fig. 3 and subsequent figures show examples of the present invention. Fig. 3 is a side view showing an example of a preheating device using a heat exchange unit, Fig. 4 is a right side view of Fig. 3, Fig. 5 is a plan view of Fig. 4, and Fig. 6 is a side view showing an example of a preheating device using a heat exchange unit. 4 is a partially cutaway side view of the heat exchange unit showing an enlarged view of the intermediate unit of FIG. 4; FIG. Fig. 7 is a partially cutaway side view of Fig. 6 seen from the right side, Fig. 8 is a partially cutaway side view of Fig. 6 seen from the left side, and Fig. 9 is a partially cutaway side view of Fig. 6 as seen from the left side.
10, FIG. 11, and FIG. 12 are schematic configuration diagrams showing other embodiments of the present invention. 1... Raw material preheating device, 2... Calcining furnace,
3... Baking furnace, 4... Cooling machine, 5...
... Raw material input chute, 6 ... Burner, 7
...Induced draft fan, 8...Ventilation duct,
9... Chute, 10... Forced blower 11... Induced draft fan, 13... Heat exchange unit, 14... Gas introduction duct , 15...
...First cylindrical body, 16... Gas discharge duct, 17... Second cylindrical body, 18... Supply chute, 19...... No. 1 separation chamber configuration housing, 19
a...First separation chamber, 20...Discharge chute, 21...Part of hopper, 22...
Discharge chute, 23...Second separation chamber, 24...
...Supply chute, 25... Re-scattering prevention plate, C4... Separation cyclone.

Claims (2)

[Scope of utility model registration request] (1) A first cylindrical body having a nearly horizontal axis and having a closed end face on the gas inlet side and an open end face on the gas outlet side, the end face on the gas inlet side having a diameter smaller than that of the first cylindrical body and arranged substantially concentrically; A second cylindrical body with an open end face and a closed end face on the gas discharge side is connected circumferentially or tangentially to the gas inlet side end of the first cylindrical body to guide rising gas from the upper heat exchange device or the outside. an introduction duct, a powder supply chute that supplies powder and granule from the upper heat exchange device to the introduction duct, an open end on the gas discharge side of the first cylindrical body and an open end on the gas introduction side of the second cylindrical body; A separation chamber surrounding the opposing part and connected to a lower heat exchange device or a powder discharge chute to the outside on the lower side, and an upper part connected to the gas discharge side end of the second cylindrical body in the circumferential direction or tangential direction. A heat exchange unit for granular material and gas, characterized in that it is comprised of a discharge duct that guides gas upward to a heat exchange device. (2) Utility Model Registration Scope of Claim 1 A heat exchange unit for granular material and gas, wherein the gas introduction side end of the second cylindrical body projects into the interior of the separation chamber.