CN101966997B - Process and device for producing pyrotechnite from sodium sulfate decahydrate - Google Patents

Abstract

The invention relates to a process and a device for producing pyrotechnite from sodium sulfate decahydrate. The process comprises the following steps of: (1) putting the sodium sulfate decahydrate into a hot melting tank for hot melting to form solution of sodium sulfate; (2) heating the solution of sodium sulfate, conveying the solution of sodium sulfate to an evaporator, concentrating and evaporating the solution of sodium sulfate, and crystallizing and precipitating part of anhydrous sodium sulfate; (3) compressing secondary steam of the evaporator, conveying the compressed steam to a heating chamber of the evaporator; and (4) performing solid-liquid separation on the dissolved solution of sodium sulfate to obtain solid anhydrous sodium sulfate, and drying, weighing and packaging. The device comprises the heat melting tank, a liquor storage tank, a feed delivery pump, a heat exchanger and the evaporator which are connected sequentially, wherein the evaporator is sequentially connected with a centrifugal machine, a mother liquor tank, a mother liquor pump and a feed inlet of the evaporator; and the evaporator is provided with a vacuum pump, and a steam outlet of the evaporator is connected with a separator, a compressor and the heating chamber of the evaporator. In the process and the device, the sodium sulfate decahydrate is subjected to melting evaporation through the technology of steam compression, so the evaporating energy consumption can be reduced, and the purity of products can reach over 99 percent; and the process and the device require investments, are high in economic benefits and save energy greatly.

Description

A kind of technology and device for producing anhydrous Glauber's salt from sodium sulfate decahydrate

technical field

The invention relates to the field of chemical technology and equipment technology, in particular to a technology for producing anhydrous Glauber's salt from sodium sulfate decahydrate and a device used in the technology.

Background technique

Existing chemical enterprises generally use sodium sulfate decahydrate (sodium sulfate decahydrate) to produce anhydrous thenardite in the following ways: steam heating, heat pipe heating, and hot air drying. Existing chemical enterprises need to consume 1 ton of anhydrous thenardite Steam 0.8-1.6 tons, power consumption 40-60kwh. Existing large-scale multi-effect evaporators have relatively low energy consumption, usually consuming 0.6-1.2 tons of steam, but large-scale multi-effect evaporators require a large investment scale, occupy a large area, and have complex structures.

At present, there are many domestic chemical enterprises that produce thenardite by-products. These enterprises have limited production capacity of thenardite and cannot invest in large-scale equipment, resulting in high energy consumption for production of thenardite, and even inability to process by-product thenardite, resulting in low economic benefits for enterprises.

Contents of the invention

For above existing technology and the deficiency of equipment, the object of the present invention is to provide the method for producing anhydrous Glauber's salt by sodium sulfate decahydrate, by melting sodium sulfate decahydrate, and adopt vapor compression technology to evaporate, to reduce evaporation energy consumption, and then Centrifuge and dry to obtain anhydrous Glauber's salt.

The purpose of the present invention is achieved by adopting the following technical solutions:

The technique of producing anhydrous Glauber's salt by sodium sulfate decahydrate comprises the following steps:

(1) Control the temperature in the Glauber's salt hot-melt tank at 33-90°C, put sodium sulfate decahydrate into the Glauber's salt hot-melt tank to melt, and form a sodium sulfate solution;

(2) The sodium sulfate solution obtained in step (1) is heated and transported into the evaporator, concentrated and evaporated in the evaporator, and part of the anhydrous sodium sulfate is crystallized;

(3) The secondary steam output from the evaporator is compressed by the compressor, and the compression ratio is maintained at 1:1.2 to 1:2.5, so that the pressure, temperature and enthalpy of the steam are increased, and then sent to the The heating chamber of the evaporator is used as heating steam to maintain the boiling state of the feed liquid and condense the heating steam itself into water;

(4) Part of the crystallized sodium sulfate solution obtained in step (2) is subjected to solid-liquid separation in a centrifuge to obtain solid anhydrous sodium sulfate, and the solution is returned to the evaporator for further concentration.

As a preferred technical solution of the present invention, in the step (2), the pressure in the evaporator is adjusted by a vacuum pump to reduce the boiling point of water, so that the sodium sulfate solution in the evaporator boils and evaporates directly without heating.

As a preferred technical solution of the present invention, the temperature range of direct boiling and evaporation of the sodium sulfate solution in the step (2) is controlled at 40-90°C.

As a preferred technical solution of the present invention, the condensed water produced in step (3) is transported into the heat exchanger to exchange heat with the sodium sulfate solution produced in step (1) to increase the temperature of the sodium sulfate solution; The final hot water is transported to the hot melting tank to heat sodium sulfate decahydrate.

As a preferred technical solution of the present invention, the anhydrous sodium sulfate produced in step (4) is dried to remove attached trace moisture to meet the water content requirement of the finished product, and then weighed and packaged.

The device for producing anhydrous Glauber's salt from sodium sulfate decahydrate, including Glauber's salt hot-melt tank, Glauber's salt liquid storage tank, feeding pump, evaporator, centrifuge, centrifugal mother liquor tank, centrifugal mother liquor pump, dryer and weighing packaging machine, The Glauber's salt hot-melt tank communicates with the Glauber's salt liquid storage tank, and the Glauber's salt liquid storage tank is connected to the feed port of the evaporator through a feed pump and a pipeline;

The discharge port of the evaporator is connected to the centrifuge through the feeding pipeline, and the centrifuge is connected to the centrifuge mother liquor tank, the centrifuge mother liquor pump and the feed inlet of the evaporator through the pipeline;

The centrifuge is sequentially connected with a dryer and a weighing packaging machine through a feeding device.

As a preferred technical solution of the present invention, a heat exchanger is also provided between the thenardite liquid storage tank and the evaporator, and the thenardite liquid storage tank is connected to the inlet of the heat exchanger through a feed pump and a pipeline, and the heat exchanger The outlet is connected to the feed port of the evaporator.

As a preferred technical solution of the present invention, the device further includes a condensed water pump, and the condensed water outlet of the evaporator is connected to the inlet of the heat exchanger through the condensed water pump and a pipeline.

As a preferred technical solution of the present invention, the steam outlet of the evaporator is connected to the separator, the compressor and the heating chamber of the evaporator in sequence through pipelines.

As a preferred technical solution of the present invention, the device also includes a vacuum pump, and the vacuum pump is connected to the material chamber of the evaporator through a pipeline.

The beneficial effects of the present invention are: compared with the prior art, the present invention melts sodium sulfate decahydrate and evaporates using vapor compression technology to reduce evaporation energy consumption, then centrifuges and dries to obtain anhydrous Glauber's salt, and the product purity can reach More than 99%, in line with the national product quality standard GB/T6009-2003, the energy consumption per ton of thenardite production is between 90-130kwh, and the energy consumption is more than 50-70% compared with ordinary steam evaporation, which has high economic benefits.

The invention has short process flow, compact device structure, small occupied area, small required space and no circulating water cooling system. The invention can not only save investment, but also achieve better energy-saving effect.

Description of drawings

Fig. 1 is a schematic diagram of a process flow of the present invention;

Fig. 2 is a structural schematic diagram of the device of the present invention.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the present invention will be further described:

As shown in Figure 1 and Figure 2, the technique of producing anhydrous Glauber's salt by sodium sulfate decahydrate comprises the following steps:

(1) Control the temperature in the hot-melt tank 1 at 33-90°C through the heating rod or heating coil in the Glauber’s salt hot-melt tank 1, put sodium sulfate decahydrate into the Glauber’s salt hot-melt tank 1 and melt to form sodium sulfate solution;

(2) The sodium sulfate solution obtained in step (1) is heated and transported into the evaporator 5, concentrated and evaporated in the evaporator 5, and part of the anhydrous sodium sulfate is crystallized;

(3) The secondary steam output from the evaporator 5 is compressed by the compressor 7, and the compression ratio is maintained at 1:1.2 to 1:2.5, so that the pressure, temperature and enthalpy of the steam are increased, and then sent to The heating chamber of the evaporator 5 is used as heating steam to maintain the boiling state of the feed liquid and condense the heating steam itself into water;

(4) Part of the crystallized sodium sulfate solution obtained in step (2) is subjected to solid-liquid separation through a centrifuge 10 to obtain solid anhydrous sodium sulfate, and the solution is returned to the evaporator 5 for further concentration.

(5) Dry the solid anhydrous sodium sulfate produced in step (4) to remove the attached trace moisture to meet the water content requirements of the finished product, and then weigh and pack it.

As a preferred embodiment of the present invention, in the step (2), the pressure in the evaporator 5 is adjusted by the vacuum pump 8 to reduce the boiling point of water, so that the sodium sulfate solution in the evaporator 5 does not need to be heated and Direct boiling evaporation, the temperature range of the direct boiling evaporation of the sodium sulfate solution in the step (2) is controlled at 40-90°C. The condensed water produced in step (3) is transported into the heat exchanger 4 to exchange heat with the sodium sulfate solution produced in step (1) to increase the temperature of the sodium sulfate solution; then the hot water after heat exchange is transported to the heat exchanger Melting tank 1 heats sodium sulfate decahydrate to reduce energy consumption and save energy.

As shown in Figure 2, the device for producing anhydrous Glauber's salt by sodium sulfate decahydrate includes Glauber's salt hot-melt tank 1, Glauber's salt storage tank 2, feed pump 3, evaporator 5, centrifuge 10, centrifugal mother liquor tank 11, centrifuge Mother liquid pump 12, drying machine 13 and weighing packaging machine 14, described Glauber's salt hot-melt tank 1 is communicated with Glauber's salt storage tank 2, and Glauber's salt storage tank 2 enters into the evaporator 5 through feeding pump 3 and pipeline The feed port is connected; the discharge port of the evaporator 5 is connected with the centrifuge 10 through the feed pipeline, and the centrifuge 10 is connected with the centrifuge mother liquor tank 11, the centrifuge mother liquor pump 12 and the feed inlet of the evaporator 5 successively through the pipeline ; The centrifuge 10 is connected with the dryer 13 and the weighing packaging machine 14 in turn through the feeding device.

In this embodiment, a heat exchanger 4 is also provided between the Glauber's salt storage tank 2 and the evaporator 5, and the Glauber's salt storage tank 2 is connected to the inlet of the heat exchanger 4 through a feed pump 3 and a pipeline. The outlet of the heater 4 is connected with the feed port of the evaporator 5 . This embodiment also includes a vacuum pump 8 and a condensate pump 9 , the vacuum pump 8 is connected to the material chamber of the evaporator 5 through a pipeline, and is used to lower the boiling point of the material liquid in the evaporator 5 . The condensed water outlet of the evaporator 5 is connected to the inlet of the heat exchanger 4 through the condensed water pump 9 and the pipeline, which is used to increase the temperature of the sodium sulfate solution, and at the same time, the hot water after the heat exchange is sent to the hot melting tank 1 to heat the sodium sulfate decahydrate , to save energy and reduce energy consumption. The steam outlet of the evaporator 5 is connected with the heating chamber of the separator 6, the compressor 7 and the evaporator 5 in turn through a pipeline, and the pressure, temperature and enthalpy of the steam are increased by compression, and then sent to the evaporator 5 The heating chamber is used as heating steam to keep the feed liquid in the evaporator 5 in a boiling state, and to condense the heating steam itself into water. In this embodiment, the heat exchanger 4 and the evaporator 5 are made of 316L stainless steel.

Claims (6)

1. a kind of technique of producing Glauber's salt anhydrous by sodium sulfate decahydrate is characterized in that comprising the following steps: (1) The temperature in the Glauber's salt hot-melt tank is controlled at 33-90°C, and sodium sulfate decahydrate is dropped into the Glauber's salt hot-melt tank to melt to form a sodium sulfate solution; (2) the sodium sulfate solution of step (1) gained is transported into an evaporator after being heated, concentrated and evaporated in the evaporator, and part of the anhydrous sodium sulfate crystallization is separated out; (3) The secondary steam output from the evaporator is compressed by the compressor, and the compression ratio is maintained at 1:1.2 to 1:2.5, so that the pressure, temperature and enthalpy of the steam are increased, and then sent to the The heating chamber of the evaporator is used as heating steam to maintain the boiling state of the feed liquid and condense the heating steam itself into water; (4) the sodium sulfate solution that the part crystallization that step (2) obtains is separated out through centrifuge and carry out solid-liquid separation, obtains solid anhydrous sodium sulfate, and solution returns evaporator to further concentrate. 2. the technique of producing anhydrous Glauber's salt by sodium sulfate decahydrate according to claim 1 is characterized in that: in described step (2), regulate the pressure in the described evaporator by vacuum pump, make the boiling point of water reduce, thereby The sodium sulfate solution in the evaporator is directly boiled and evaporated without heating. 3. the technique for producing anhydrous Glauber's salt by sodium sulfate decahydrate according to claim 2 is characterized in that: in the described step (2), the temperature range of direct boiling and evaporation of sodium sulfate solution is controlled at 40-90°C. 4. the technique of producing anhydrous Glauber's salt by sodium sulfate decahydrate according to claim 1 is characterized in that: the condensed water that step (3) produces is transported into heat exchanger and the described sodium sulfate that step (1) produces Heat exchange of the solution to increase the temperature of the sodium sulfate solution; and then transfer the hot water after heat exchange to the hot melting tank to heat the sodium sulfate decahydrate. 5. the technique for producing anhydrous Glauber's salt by sodium sulfate decahydrate according to claim 1 is characterized in that: the anhydrous sodium sulfate produced in the step (4) is dried to remove attached trace moisture to reach the water content of finished product Requirements, then weigh the package. 6. A device for producing anhydrous Glauber's salt by sodium sulfate decahydrate, characterized in that: the device includes Glauber's salt hot-melt tank, Glauber's salt liquid storage tank, feed pump, evaporator, centrifuge, centrifugal mother liquor tank, centrifugal mother liquor A pump, a dryer, and a weighing and packaging machine, the Glauber's salt hot-melt tank communicates with the Glauber's salt liquid storage tank, and the Glauber's salt liquid storage tank is connected to the feed port of the evaporator through a feeding pump and a pipeline; The discharge port of the evaporator is connected to the centrifuge through the feeding pipeline, and the centrifuge is connected to the centrifuge mother liquor tank, the centrifuge mother liquor pump and the feed inlet of the evaporator through the pipeline; The centrifuge is sequentially connected with a dryer and a weighing packaging machine through a feeding device; A heat exchanger is provided between the Glauber's salt liquid storage tank and the evaporator, the Glauber's salt liquid storage tank is connected to the inlet of the heat exchanger through a feed pump and a pipeline, and the outlet of the heat exchanger is connected to the feed port of the evaporator ; The device also includes a condensed water pump, and the condensed water outlet of the evaporator is connected to the inlet of the heat exchanger through the condensed water pump and a pipeline; The steam outlet of the evaporator is connected with the separator, the compressor and the heating chamber of the evaporator in sequence through pipelines; The device also includes a vacuum pump, which is connected with the feed chamber of the evaporator through a pipeline.

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