RU109460U1 - PLANT FOR PRODUCTION OF α-GYPSA - Google Patents

Abstract

 1. Installation for the production of α-gypsum, consisting of aggregates for grinding raw materials, a dehydrogenation reactor CaSO4 · 2H2O, a filter and a conveyor-dryer, characterized in that spiral conveyors are used as a reactor-dehydrator, heater, desiccant and cooler. ! 2. Installation according to claim 1, characterized in that a filter is installed between the reactor-heater and the dehydrator and the spiral conveyor-dryer and the product cooler to exhaust the gas-vapor stream from them. ! 3. Installation according to claim 1, characterized in that a bag filter made of stainless mesh with reverse air blowing is used as a dust and gas filter.

Description

Known plants for the production of gypsum [1, 2, 3] from natural gypsum stone or phosphogypsum [4, 5, 6, 7, 8]. All these installations include the required units:

- grinding of raw materials;

- conveyors of bulk solids;

- drying drums;

- raw and food bunkers;

- dispensers and closures of bulk solids;

- the main unit is a gypsum boiler, in which the main dehydrogenation of calcium sulfate takes place.

CaSO ₄ · 2H ₂ O → CaSO ₄ · 0.5Н ₂ О 1.5Н ₂ О

- other cars and devices.

Such a number of units makes installation difficult, cumbersome and expensive. In addition, a large number of units and their sizes give rise to large heat losses.

For example: the weight of the unit [2] is 70 tons with a capacity of 7.5 t / gypsum per hour.

There are also known installations in which the gypsum boiler and a large number of other units are replaced by a mill, which, in addition to its direct purpose, also provides heating and dehydration of gypsum stone. But, since dehydration in the mill is not sufficient, a reactor with a suspended layer of a part of gypsum dust is used, which produces complete dehydration at a temperature of about 500 ° C, followed by mixing with the rest of the gypsum, and, thus, mixing, forming CaSO ₄ · 0.5H ₂ O.

Such an installation is somewhat simpler, cheaper and less metal-intensive. However, it requires an apparatus with a fluidized bed, and, therefore, its significant hydraulic resistance (as a result of the presence of a blower), as well as the fact that a stream of flue gases containing soot polluting gypsum enters this apparatus.

The proposed installation is relieved of many of the above disadvantages, which made it possible to significantly simplify the process, reduce the weight of the equipment, heat loss and energy consumption of the process and obtain a clean gypsum free of soot. The possibility of carrying out the process under pressure of water vapor dehydration CaSO ₄ · 2H ₂ O, which allows to obtain a more durable α-gypsum.

The essence of the proposed installation is that instead of a gypsum boiler, we use a spiral reactor [9]. This made it possible to combine with the process of dehydration the processes of heating, drying, filtering, cooling and transporting raw materials and products, carrying out the dehydration process under water vapor pressure. The latter makes it possible to remove hydrated water in liquid form, excluding the evaporation process (water vapor is not removed from the reactor). This reduces the heat consumption by the latent heat of vaporization of about 500 kcal per kg.

According to the data obtained in pilot plants in spiral conveyor reactors, a very high heat transfer coefficient through the reactor wall is maintained, and due to this, high heat stress is permissible, which ensures compactness and low weight of the reactor.

Figure 1 presents the diagram of the proposed installation for the production of α-gypsum using as a reactor - a dehydrator, heater, dryer and cooler of spiral conveyors:

1. Raw materials, such as gypsum;

2. Dispenser of raw materials;

3. Raw material crusher;

4. Belt conveyor;

5. Magnetic trap;

6. The mill;

7. Gateway feeder;

8. A spiral reactor, which is a spiral conveyor (pipe with a spiral rotating in it) with devices for heating the raw materials and producing their dehydration either by electric heating or by fire heating, or in any other way;

9. Spiral - mover of bulk product;

10. Motor gearbox - spiral drive;

11. A spiral conveyor of gypsum dehydrate;

12. Water;

13. Sump tank

14. Dust filter air discharge;

15. Spiral conveyor-dryer of gypsum;

16. Gypsum - a finished product

17. Compressed air;

18. Blower;

19. Packing machine;

20. Drain of crystalline water;

21. Bunker of commodity α-gypsum;

22. Reversible conveyor;

23. Reversible gear motor;

24. Storage silo of commodity α-gypsum.

Gypsum stone 1 (or other raw materials) enters the dispenser 2, feeding the raw materials to the crusher 3 (for example, jaw). The metal inclusions are removed by a magnetic trap 4 on the conveyor belt 5, and the crushed material is dumped into the receiving hopper of the fine grinding mill 6 (for example, hammer, although a rotary or disk disperser is preferable to us).

The finely ground gypsum powder from the mill 6, through the lock feeder 7, is dumped into the raw material receiver of the spiral reactor 8, where, moving along the reactor pipe due to the rotation of the spiral 9, it is heated to a temperature of 120 - 150 ° C and dehydrated to CaSO ₄ · 0.5H ₂ O under water vapor pressure.

The resulting water 12 with a certain amount of gypsum powder from the reactor 8 enters the settling tank 13, where the gypsum settles, and the water is sent to the drain 20. The precipitated dehydrate is captured by the spiral 9 of the conveyor 11 and advances to the junction of the reactor 8 and the conveyor 11, freeing itself along the way from a drop of moisture.

Gypsum from the junction of the reactor 8 and the conveyor 11 through the lock gate 7 enters the spiral conveyor dryer 15, where the dehydrate is dried and sent either to the packaging machine 19 or to the silo 24 for storing commodity α-gypsum using a reversible conveyor 22.

To intensify the processes of heating, dehydrogenation, cooling and drying, air 17 is supplied from the blower 18 to the reactor.

Heating of the reactor 8 is possible in any way possible.

The spiral drives 9 are carried out by gear motors 10.

As a filter for separating the vapor-gas stream from gypsum powder, a bag filter 14 with reverse air purge 20 is used, for example, an effective filter according to the RF patent No. 2010120320 dated 05/21/2010 [10].

The reactor group, consisting mainly of spiral conveyors and a filter 8, 14, 15, was proposed by us for a number of processes, and it showed stable, effective trouble-free operation in pilot plants.

The proposed installation can be used to obtain β-gypsum. In this case, there is no need for a settling tank 13 and a conveyor 11.

Used Books:

1. http://www.newchemistry.ru/printletter.php?n_id=5373

2.http: //www.tobis.ru/products/gips

3. http://www.newchemistry.ru/letter.php?n_id=6049&cat_id=5&pageid=3

4.http : //www.diplomnic.ru/rabota/18964.html

5. http://www.newchemistry.ru/printletter.php?n_id=4046

6.http: //ru.wikipedia.org/wiki/%C3%E8%EF%F1

7.http: //stroy-server.ru/notes/gipsovve-vyazhushchie-veshchestva

8.http: //www.newchemistry.ru/printletter.php? N_id = 4046

9. RF patent for Utility Model No. 102615 “Device for thermal annealing of carbon black”;

10. Application for the grant of a patent of the Russian Federation for invention No. 2010120320 "Bag filter for cleaning gas from dust with short-pulse blowing."

Claims (3)

1. Installation for the production of α-gypsum, consisting of aggregates for grinding raw materials, a dehydrogenation reactor CaSO ₄ · 2H ₂ O, a filter and a conveyor-dryer, characterized in that spiral conveyors are used as a reactor-dehydrator, heater, desiccant and cooler. 2. Installation according to claim 1, characterized in that a filter is installed between the reactor-heater and the dehydrator and the spiral conveyor-dryer and the product cooler to exhaust the gas-vapor stream from them. 3. Installation according to claim 1, characterized in that a bag filter made of stainless mesh with reverse air blowing is used as a dust and gas filter.