JPS5874531A - Calcining device for foamed ore grains - Google Patents

Abstract

PURPOSE:To decrease the amt. of fuel to be used and to permit the use of raw material ores from coarse to fine grains by combining a preheater for raw ore grains by the waste gases of combustion of a vertical calcining furnace using a vertical calcining furnace and a dust collector and a grain screening device for foamed ore grains using an another dust collector. CONSTITUTION:Raw ore grains are charged into a gas duct connecting a cyclone 4 and a cyclone 5 through a feed port 6 and disperse in the flow of combustion gases. The ore grains are separated from the combustion gases in the cyclone 5. The separated raw ore grains fall into a gas duct connecting the cyclones 4 and 3, and are dispersed into the flow of the combustion gas from the cyclone 3, and arrive at the cyclone 4. Here, the ores are reseparated and fall into a vertical calcining furnace 1 where the greater part are calcined and expanded by the combustion heat of burners 8. The separated ore grains arrive at a cyclone 2. The foamed ore grains of intermediate grain sizes are separated here and those of fine grains are further introduced into the cyclone 3 and are separated.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a foamed mineral grain firing apparatus for firing foamed mineral grains such as pearlite and obsidian to produce foamed mineral grains called perlite.

Conventional techniques similar to the present invention include those that utilize a rotary kiln and those that utilize a vertical kiln.

Rotary kilns have the advantage of being able to extend the residence time of mineral grains and firing materials of various grain sizes, but it is difficult to insulate the kiln, and the amount of heat dissipated by the kiln is limited. Since it is difficult to recover exhaust heat from combustion exhaust gas, a large amount of fuel is used. Further, there is a drawback that each foamed mineral grain must be classified according to particle size after firing.

Further, in those using a vertical kiln, even if the amount of heat dissipated from the furnace can be reduced by insulating the furnace wall, the exhaust heat recovery of the combustion gas is not sufficient.

The amount of combustion used will still be large. In addition, the residence time of mineral particles is short, and relatively coarse mineral particles (particle size after foaming of 5 mm or more) have the disadvantage that they fall from the bottom of the furnace without being fired and foamed.

The present invention eliminates the above-mentioned drawbacks, namely, a vertical calcining furnace, a vertical calcining furnace using a dust collector, an initial preheating device for raw ore using combustion exhaust gas, and a foamed mineral using a separate dust collector. By combining the particle size separation device, it is possible to solve the disadvantages of the conventional foamed mineral granule calcination device, which has insufficient exhaust heat recovery and consumes a large amount of fuel, and to separate the foamed mineral granules by particle size after calcination. In addition to improving the disadvantages of having to ship the minerals, by combining the vertical kiln with a rotary kiln, we solved the difficulty of firing the coarse grains of the conventional vertical kiln, and the amount of fuel used was extremely small. Grains can be taken out by particle size,
The purpose of this project is to provide a foamed mineral grain firing device that is capable of firing raw ore grains of various grain sizes.

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example in which primary ore containing no coarse grains is fired.

1 is a vertical firing furnace for firing foamed mineral grains. 2
and 3 are cyclones for separating fired and foamed mineral grains according to particle size using firing gas. The sizes of cyclone 2 and O are set to appropriate sizes that allow foamed mineral particles to be taken out according to particle size. (The cyclone 2 is larger than the cyclone filter.) Cyclones 4 and 5 are used to preheat and separate the primary ore (expandable mineral grains) using combustion gas. Reference numeral 6 is the input pipe of the raw ore initial stage, 7 is the exhaust fan for combustion exhaust gas, and 8 is the burner of the vertical kiln.

The first stage of raw ore mining is from input pipe 10 to cyclone 4 and cyclone 5.
into the gas duct connecting the combustion gas and dispersed in the combustion gas flow. The raw ore absorbs the sensible heat of the combustion gas and separates it from the combustion gas in cyclone 5. The raw ore is taken out from the bottom of the cyclone 5 and thrown into the gas duct connecting it to the cyclone 4. The raw ore is dispersed in the gas duct into the combustion gas stream discharged from the cyclone 6, and further heated by the sensible heat of the combustion gas.

Sent to Cyclone 4. In cyclone 4, the raw ore is reseparated, and from the bottom of cyclone 4 the vertical kiln 1 is transferred.
will be put into the During this period, the initial temperature of the raw ore was 600°C to 700°C.
is preheated to. Several burners 8 are attached to the bottom of the vertical firing furnace 1. The combustion heat generated by this group of burners causes most of the raw ore to sinter and foam, and is floated by the upward flow of combustion gas in the furnace and transported to cyclone 2.

The foamed mineral granules are separated from the combustion gas in the cyclone 2, and the foamed mineral granules of intermediate size are removed from the lower part of the cyclone 2. Fine foam mineral grains.

It is then introduced into cyclone O, separated by the same cyclone filter, and taken out from the bottom.

The same effect can be achieved even if the vertical firing furnace 1 is provided with another combustion chamber in place of the burner 8 and the high-temperature combustion gas is introduced into the vertical firing furnace 1.

FIG. 2 shows an example used in the initial firing of raw ore containing coarse grains. This embodiment differs from the embodiment shown in FIG.
This is because we have established the following.

11 is a rotary kiln burner.

Other parts that are the same or correspond to those in FIG. 1 are designated by the same reference numerals, and their explanations will be omitted.

Some coarse particles of the Niwahara mineral grains that have not been completely foamed and fired in the vertical kiln 1 are discharged from the lower part of the vertical kiln 1 and put into the rotary kiln 9.

In the rotary kiln 9, the coarse particles are fired and foamed by a countercurrent flow to the flame of the burner 11, cooled by the cooler 10, and taken out of the system as a product.

Since the present invention is constructed and operated as shown in the embodiments described above, it is possible to achieve the following excellent effects.

(1) The firing of foamed mineral grains is mainly carried out in a vertical firing furnace that can strengthen the insulation of the furnace wall, and the sensible heat of the combustion gas is used to preheat the raw ore (expandable mineral grains). Since it can be fully utilized, the amount of fuel used can be reduced considerably. Namely.

Compared to conventional rotary kilns, the amount of fuel used can be reduced to about half.

(2) Even when raw mineral materials containing from coarse to fine grains are used, if a device like the one shown in Figure 2 is used, the intermediate grains and fine grains of the raw mineral grains can be fired in a vertical kiln, and the coarse grains can be Firing in a rotary kiln allows each furnace to be operated under optimal operating conditions.

(3) Due to the action of the vertical kiln and dust collector, the foamed mineral grains can be separated into coarse, medium, fine, etc. grains and taken out in a separated state. As in the case.

There is no need to separate the foamed mineral particles by particle size after firing.

FIG. 3 shows another embodiment of the invention.

　　　　　　゛ This embodiment differs from the embodiment shown in FIG.

Cyclones 12 and 1 filter are provided to cool and separate intermediate grains and fine grains of the hot raw mineral grains separated by cyclone 2 and cyclone 6. The inlet ducts of cyclones 12 and 13 are the blower 14 and duct 1.
5 and 16, and the outlet duct is tangentially connected to the vertical kiln 1.

Other parts that are the same as or correspond to those in FIG. 2 are designated by the same reference numerals, and their explanations will be omitted.

The hot raw mineral grains separated by the cyclone 2 and the filter are fed into ducts 15 and 16.

Dispersed in the cold air sent from the blower 14 and cooled,
Separated in cyclones 12 and 16.

On the other hand, the cooling air is heated to 300-400°C.

The air is sent to the vertical firing furnace 1 from the outlet ducts of the cyclones 12 and 13, and becomes combustion air.

In this embodiment, by providing the cyclones 12 and 13, not only the foamed mineral grains to be made are cooled, but also the sensible heat they possess is absorbed.

The amount of fuel held can be further reduced.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of one embodiment of the foamed mineral grain firing apparatus of the present invention, and FIGS. 2 and 3 are system diagrams of other embodiments of the present invention. 1 is a vertical kiln, 2, 3, 4, 5, 12 and 13 are cyclones, 6 is a feed pipe for raw mineral particles, 7 is an exhaust fan, 8 is a burner for the vertical kiln, 9 is a rotary kiln, 10 is a cooler, 11 is a rotary kiln burner, 14 is a blower, 15
and 16 is cyc oy, 2 and 13 OA'D I
X”, )-c Ah. Patent applicant: Ube Industries, Ltd. Figure 1 Figure 2 Figure 3 Procedural amendment (voluntary) Showa! Commissioner of the Japan Patent Office 2017-2015 Crest 1, Indication of the case Patent Application No. 170706/1983 Name of the invention Foamed mineral grain firing device 3, person making the amendment Relationship to the case Patent applicant □ Postal code 755 Yamaguchi Prefecture 1-12-32 Nishihonmachi, Ube City (020)
Ube Industries Co., Ltd. Telephone: 0!5 (581) 3!511 4. Date of amendment order There is no amendment order. 5. The "Detailed Description of the Invention" column of the specification to be amended and the drawings attached to Application-11. 6. Contents of amendment 6.1 “Input tube 10” on page 4, line 13 of the specification
6.2 Among the drawings attached to the application, Figures 2 and 5 are amended as shown in the attached "Drawing showing the amendments". In other words, the code (number) of one drawing is corrected so that it is not assigned. 7. One or more copies of drawings showing amendments to the list of attached documents Figure 2 Figure 3

Claims (3)

[Claims] (1) A plurality of dust collectors are arranged in series through a duct between the exhaust fan and the vertical kiln, and the raw mineral grains are preheated in an appropriate number of dust collectors close to the exhaust fan. A foamed mineral grain firing device characterized in that the foamed mineral grains fired and foamed in a vertical firing furnace in a residue dust collector are separated according to particle size. (2) A rotary kiln is connected to the vertical kiln, and raw mineral grains that have not been fired and foamed in the vertical kiln are fired and foamed in the rotary kiln. Foamed mineral grain firing equipment. (3) The inlet ducts of multiple dust collectors installed in parallel via ducts connected to the blower are connected to the dust collectors for separating foamed mineral particles installed between the vertical firing furnace and the exhaust fan. Claim (1) or (1), characterized in that the outlet of the duct is communicated with the vertical firing furnace.
2) The foamed mineral grain firing device described in section 2).