JPS58115048A - Calcined plaster continuous manufacture device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] For further details, please refer to the apparatus for producing calcined gypsum of uniform quality,
The present invention relates to an externally heated double-tube type manufacturing device having a partition plate inside, which is capable of producing the same.

Conventional methods for producing high-strength plaster include the pressurized steam method;
There are pressurized aqueous solution methods, gelatinization methods by adding crystal modifiers, etc. Among these methods, the continuous production method is to convert the resulting semi-hydrated gypsum into semi-hydrated gypsum by treating it in hot water under pressure. There are methods such as separating and recovering gypsum from hot water or bringing superheated steam into contact with industrial water gypsum, but the former requires drying of the product and has problems such as scale adhesion inside the equipment. Equipment that uses the latter method includes a bag mill type and a rotating cylinder type, but the plaster tends to flow during the dehydration process and is discharged with insufficient firing, or conversely, some parts are overcooked, resulting in poor quality. It has the disadvantage that it is non-uniform. Furthermore, the rotary cylindrical type has the problem of being difficult to seal.

- There is a method using an autoclave to obtain high-strength gypsum of uniform quality, but since it is a patch method, the work is complicated and is preferable from the viewpoint of productivity, as it does not shift.

In view of the above circumstances, the inventor of the present invention has conducted various studies on a continuous type device that can produce a uniform quality of calcined plaster, is relatively easy to handle, and can increase productivity. We discovered that it is possible to prevent variations in product quality by providing multiple partition plates and stirring blades inside the cylinder, and that it is also possible to freely produce α-type and β-type calcined gypsum using a relatively simple sealing device. The invention has been completed.

The apparatus of the present invention is fired in a horizontal double cylinder pressure-resistant vessel having an outer cylinder that can be heated with hot gas or steam, but the temperature inside the inner cylinder is 130 to 2oO℃ and the pressure is 3 Kg/cJ or less. Use superheated steam or saturated steam of 2-5 K9/cdl. At least three partition plates are installed inside the inner cylinder to prevent short circuits in the green gypsum. The Sansui gypsum supplied into the inner cylinder is dried, heated, boiled, and finished in the order of flow firing to become embossed, but the number of partition plates does not necessarily match each category above. The number can be appropriately selected depending on the length of the firing device, the amount of raw material supplied, the temperature, etc.

A stirrer is installed in each section divided by a partition plate so that one or more blades for stirring can be inserted into each section. The blades only need to play the role of stirring the raw materials so that they are of uniform quality in each division, and it is not necessarily necessary to add an angle to make it easier to send the raw materials to the next division. This is because if there is a feeding angle, there is a risk that the material will be sent to the next category due to premature burns. The continuous supply of raw material from each section naturally overflows each partition plate and is sent to the next section.

In order to supply the raw material hydrated plaster to the inner cylinder, it is carried out through one feeder from the hopper. As will be described later, in order to obtain α-type calcined gypsum, the inside of the inner cylinder must be kept under pressure. The raw material supply port and product discharge port must be air tight. Therefore, a means to feed the raw material while sealing the inside of the inner cylinder is required, and there are various ways to do this, but a relatively simple one is a screw conveyor. This objective can be achieved by providing one or more dunnage holes. Similarly, the product outlet also serves the purpose of a screw conveyor or a screw conveyor and a ball valve.

As the raw material engineered water gypsum is heated, the attached water and combined water turn into steam, and the pressure inside the cylinder increases because the inside of the cylinder is airtight.

If you continue firing as is, α-type firing and plaster will be produced.
If the generated steam is released to the outside and fired at normal pressure, β-type calcined gypsum is produced. Since the cylinder is equipped with a pressure regulating means that communicates with the outside, it is possible to freely produce α-type and β-type calcined gypsum. A pressure regulating valve is preferably used as the pressure regulating means for convenience.

The invention will be explained with reference to the figures.

The figure shows an embodiment of the present invention, in which a heating gas suction windmill 1
4, then ignite the burner 9 and turn the agitator 15. Subsequently, Sansui gypsum is put into the raw material pumper 1 as a raw material, and a raw material supply screw conveyor 2 continuously supplies the Sansui gypsum to the inner cylinder 5 of the horizontal triple cylinder pressure container. The inner cylinder 5 has four partition plates, and the blades 3 of the stirrer 15 stir each partitioned section. When the raw material supply amount, heating gas air volume, and heating gas temperature are set to predetermined values, the steam generated from the trihydrate transforms the trihydrate into high-strength hemihydrate gypsum. After a certain period of time has elapsed, the product is transported to the output sheet, and the product discharge screw conveyor °8 is operated to continuously discharge the product. The internal pressure of the pressure-resistant container is maintained at less than I kg//cn F by the pressure regulating valve 6, and excess steam is discharged to the outside of the system.

The pressure container 5 has a material sealing mechanism using a screw conveyor at its outlet and outlet, and is further sealed by a damper 16 in a hopper and a ball valve 17 at its outlet. A high-pressure asbestos packing was used for the drive bearing part of the agitator 15.

According to the present invention, since it is a dry manufacturing method, there is no need to dry the product, and a product with uniform quality can be continuously obtained using a partition plate and an agitator. Moreover, the product quality has a 2-hour wet compressive strength of 250 Kq/c- or higher. - It is possible to produce high-strength α-type hemihydrate gypsum.

Further, by adjusting the pressure during dehydration, it is possible to produce α-type and β-type, and it is an economically advantageous manufacturing method that requires less fuel and equipment, and its industrial value is extremely large.

Next, the present invention will be explained with reference to examples.

The results of continuous operation for 10 days are shown. As a conventional method, a paddle type baking device (having the same capacity as the device of the present invention) and an autoclave (batch method) were listed for comparison.

[Brief explanation of the drawing]

The figures show one embodiment of the device of the present invention, with A showing a side sectional view and B showing a front sectional view. 1... Raw material hopper 2... Raw material supply screw conveyor 3... Stirring blade 4... Partition plate 5... Pressure-resistant container inner cylinder 6... Pressure adjustment valve 7.12.13... Thermometer 8...・Product discharge screw conveyor 9...Burner 10...Hot stove 11...Outer tube I4 for heating pressure-resistant container ・Heating gas suction windmill 15...Agitator 16...Damper 17...
Ball valve patent applicant Akira Ito, agent of Nippon Cement Co., Ltd., patent attorney

Claims (1)

[Scope of Claims] (1) A horizontal double-tube pressure-resistant container having an outer cylinder for heating, the inner cylinder having at least three partition plates and raw materials in each section partitioned by the partition plates. A stirrer having a stirring blade and a pressure regulating means communicating from the inside of the inner cylinder to the outside are provided, and a means for supplying raw materials and discharging products while sealing the inside of the cylinder is provided at the entrance and exit of the inner cylinder. Continuous system for firing hydrated gypsum characterized by (2)
Continuous manufacturing apparatus according to claim (1), in which the heating outer cylinder is heated by passing hot gas or steam (3) The means for supplying raw materials and discharging products while sealing the inside of the inner cylinder is a screw conveyor. Claim No. (1)
Continuous manufacturing apparatus (4) according to claim 1 The continuous manufacturing apparatus (5) according to claim 1, wherein the means for supplying raw materials while sealing the inside of the cylinder is a screw conveyor and a damper. The continuous manufacturing apparatus according to claim (1), wherein the means for discharging the product while discharging the product is a screw conveyor and a ball valve.