阅读说明：本技术 一种粒状原硅酸钠的生产工艺及生产设备 (Production process and production equipment of granular sodium orthosilicate ) 是由 郑卫国 王云枫 张建友 徐康 王善鹏 李学坤 梁坤 宋万兵 于 2019-11-08 设计创作，主要内容包括：本发明公开了一种粒状原硅酸钠的生产工艺及生产设备,其中,生产过程包括如下步骤：(1)石英砂与烧碱在蒸汽作用下反应,得到粗制液体硅酸钠；(2)粗制液体硅酸钠过滤,得到精制液体硅酸钠；(3)精制液体硅酸钠调模,得到液体原硅酸钠；(4)液体原硅酸钠与小苏打混合后造粒,得到粒状原硅酸钠。本发明通过加入小苏打,使粒状原硅酸钠粒度得到明显改善,降低细粉量,提高粒状原硅酸钠硬度,减少干燥时间,抑制原硅酸钠吸潮倾向。本发明的工艺和设备采用DCS控制系统,实现了连续化生产,提高了产量,降低了劳动强度,降低了生产成本,改善了生产环境,达到了节能减排的效果。(The invention discloses a production process and production equipment of granular sodium orthosilicate, wherein the production process comprises the following steps: (1) reacting quartz sand with caustic soda under the action of steam to obtain crude liquid sodium silicate; (2) filtering the rough liquid sodium silicate to obtain refined liquid sodium silicate; (3) refining the liquid sodium silicate and adjusting the mold to obtain liquid sodium orthosilicate; (4) mixing the liquid sodium orthosilicate with baking soda and granulating to obtain granular sodium orthosilicate. The granular sodium orthosilicate water-absorbing agent has the advantages that the granular sodium orthosilicate is obviously improved in granularity by adding the baking soda, the fine powder amount is reduced, the hardness of the granular sodium orthosilicate is improved, the drying time is shortened, and the moisture absorption tendency of the sodium orthosilicate is inhibited. The process and the equipment adopt a DCS control system, realize continuous production, improve the yield, reduce the labor intensity, reduce the production cost, improve the production environment and achieve the effects of energy conservation and emission reduction.)

1. The production process of granular sodium orthosilicate is characterized by comprising the following steps of:

(1) reacting quartz sand with caustic soda under the action of steam to obtain crude liquid sodium silicate;

(2) filtering the rough liquid sodium silicate to obtain refined liquid sodium silicate;

(3) refining the liquid sodium silicate and adjusting the mold to obtain liquid sodium orthosilicate;

(4) mixing the liquid sodium orthosilicate with baking soda and granulating to obtain granular sodium orthosilicate.

2. The process for producing granular sodium orthosilicate according to claim 1, wherein in the step (1), the quartz sand is quartz sand containing silica in 99.00-100%, the caustic soda is 50% of caustic soda, and the mass ratio of the quartz sand to the caustic soda is 1: 1.3-1.6;

preferably, in the step (1), the vapor pressure is 0.6-1.6MPa, the reaction temperature is 130-220 ℃, the reaction pressure is 0.7-1.2MPa, and the reaction time is 4-6 hours.

3. The process for producing granular sodium orthosilicate according to claim 1, wherein in the step (2), the filtration pressure is 0 to 0.4MPa, the filtration temperature is 80 to 100 ℃, and the filter aid for filtration is quartz sand;

preferably, in the step (2), the modulus of the refined liquid sodium silicate is 1.60-1.80, and the Baume degree is 62-64.

4. The process for producing granular sodium orthosilicate according to claim 1, wherein in the step (3), 50% of caustic soda is adopted for mold adjustment, and the mass ratio of the refined liquid sodium silicate to the 50% of caustic soda is 1: 1.0-1.2;

preferably, in the step (3), the modulus of the liquid sodium orthosilicate is 0.47-0.57, the temperature is 80-90 ℃, and the Baume degree is 49-50 ℃.

5. The process for producing granular sodium orthosilicate according to claim 1, wherein in the step (4), the baking soda is mixed with the liquid sodium orthosilicate in the form of 30% baking soda aqueous solution, and the quality of the baking soda is 8-10% of that of the liquid sodium orthosilicate;

preferably, in the step (4), the granulation is carried out in a dryer, liquid sodium orthosilicate is conveyed into the dryer through a jet pump, the jet pressure of the jet pump is 0.20-0.30MPa, the rotating speed of the dryer is 5-8 r/min, the mass ratio of the liquid sodium orthosilicate to the seed crystal in the dryer is 1:5-8, the temperature of drying air for drying is 300-;

in the step (4), cooling is carried out after granulation, and the temperature of cooling air for cooling is 10-40 ℃.

6. A production plant for granular sodium orthosilicate, characterized in that it comprises:

the reaction kettle is used for reacting quartz sand and caustic soda to obtain crude liquid sodium silicate;

a feed inlet of the filter is connected with a discharge outlet of the reaction kettle and is used for filtering the rough liquid sodium silicate to obtain refined liquid sodium silicate;

the feed inlet of the batching tank is connected with the discharge outlet of the filter and is used for feeding refined liquid sodium silicate to adjust the mould to obtain liquid sodium orthosilicate and mixing the liquid sodium orthosilicate with sodium bicarbonate to obtain batching;

and a feed inlet of the granulation system is connected with a discharge outlet of the batching tank and is used for batching and granulating to obtain granular sodium orthosilicate.

7. The apparatus for producing sodium orthosilicate according to claim 6, further comprising:

the discharge port of the pulping tank is connected with the feed port of the reaction kettle and is used for mixing caustic soda and quartz sand and supplying a mixture of the caustic soda and the quartz sand to the reaction kettle;

the discharge port of the caustic soda tank is connected with the feed port of the pulping tank and is used for storing caustic soda and supplying the caustic soda to the pulping tank;

the sand warehouse is connected with the feed inlet of the pulping tank, and is used for storing quartz sand and supplying the quartz sand to the pulping tank;

the feeding port of the alkali mixing tank is connected with the reaction kettle, and the discharging port of the alkali mixing tank is connected with the filter and is used for receiving the rough liquid sodium silicate, facilitating parameter testing and supplying the rough liquid sodium silicate to the filter after the test is qualified;

and the control system is used for controlling the production process.

8. The apparatus for producing granular sodium orthosilicate according to any one of claims 6-7, wherein the granulation system comprises:

the dryer is connected with the discharge port of the batching tank at the feed inlet and is used for batching, granulating and drying to obtain granular sodium orthosilicate;

the feed port of the screening machine is connected with the discharge port of the dryer and is used for screening granular sodium orthosilicate;

the cooling machine is connected with the discharge port of the sieving machine at the feed port and is used for cooling the granular sodium orthosilicate with qualified grain size;

a finished product bin, wherein a feed inlet of the finished product bin is connected with a discharge outlet of the cooler and is used for storing the cooled granular sodium orthosilicate;

the feed inlet of the pulverizer is connected with the discharge outlet of the sieving machine and is used for pulverizing the granular sodium orthosilicate with the screened grain diameter larger than the qualified grain diameter;

the fine powder bin is connected with the discharge port of the pulverizer and the discharge port of the screening machine respectively at the feed inlet thereof and is used for storing the granular sodium orthosilicate with the grain size smaller than the qualified grain size and the crushed granular sodium orthosilicate;

the seed crystal inlet of the dryer is connected with the discharge hole of the fine powder bin;

preferably, the discharge hole of the cooler is connected with the feed inlet of the finished product bin through an iron remover;

the air inlet of the cooler is connected with the outside atmosphere through a second blower and a dehumidifier, and the air outlet of the cooler is connected with the outside atmosphere;

the air outlet of the cooler is connected with the outside atmosphere through a second dust remover, and the discharge hole of the second dust remover is connected with the feed inlet of the fine powder bin.

9. The apparatus for producing sodium orthosilicate according to claim 8, wherein the granulation system further comprises:

the drying air duct is internally provided with a first circulating fan and a heating structure, an air outlet of the drying air duct is connected with an air inlet of the dryer, the air inlet of the drying air duct is connected with an air outlet of the dryer, the drying air duct is provided with a first exhaust port which can be opened and closed, and the first exhaust port is connected with the external atmosphere;

preferably, the first exhaust port is connected with the outside atmosphere through a first dust remover, and the discharge port of the first dust remover is connected with the feed port of the fine powder bin;

the granulation system further comprises:

the air inlet of the combustion furnace is connected with the outside atmosphere through a first air blower and is used for combusting combustible materials;

the flue gas flow channel is internally provided with a second circulating fan, the gas outlet of the flue gas flow channel is connected with the gas inlet of the combustion furnace, the gas inlet of the flue gas flow channel is connected with the gas outlet of the combustion furnace, the flue gas flow channel is provided with a second gas outlet which can be opened and closed, and the second gas outlet is connected with the outside atmosphere;

the first heat exchanger, first heat exchanger first flow path constitute the flue gas wind channel, and first heat exchanger second flow path constitutes dry wind channel, and first heat exchanger constitutes heating structure.

10. The apparatus for producing granular sodium orthosilicate according to claim 9, wherein the granulation system further comprises:

a second heat exchanger;

the air inlet of the combustion furnace is connected with the outside atmosphere through an air inlet channel, the second air outlet is connected with the outside atmosphere through an exhaust channel, the air inlet channel forms a first channel of a second heat exchanger, and the exhaust channel forms a second channel of the second heat exchanger;

preferably, the air inlet duct is provided with a filter.

Technical Field

The invention belongs to the field of sodium silicate production, and particularly relates to a production process and production equipment of granular sodium orthosilicate.

Background

Sodium silicate, commonly known as water glass and sodium silicate, with the molecular formula Na₂O·m SiO₂Where m is the modulus, i.e. SiO in the product₂And Na₂The molar ratio of O is generally 1.00 to 3.40.

Sodium orthosilicate, also known as sodium orthosilicate, having a molecular formula of 2Na₂O·SiO₂Modulus is 0.50; the sodium orthosilicate belongs to an inorganic salt product, is a non-toxic, tasteless and nuisanceless white particle, is easily soluble in water, is insoluble in alcohol and acid, is alkaline in aqueous solution, is stronger in alkalinity than sodium metasilicate, is easy to absorb moisture and decompose when placed in the air, and has the functions of descaling, emulsifying, dispersing, moistening, permeating and buffering pH value.

The sodium orthosilicate is widely applied to preparing various lotions, metal surface treatment, ceramic grinding aids, refractory raw materials, plastic-retaining and water-retaining raw materials, oil removal, textile printing and dyeing auxiliaries, paper deinking agents and the like.

The traditional process for producing sodium orthosilicate mainly comprises three methods:

one is a solid mixing method, sodium metasilicate and granular caustic soda are mixed, manually stirred and mixed, and then the mixture is crushed and sieved to obtain a product meeting the requirement on granularity. The product produced by the production process is only the mixing of silicon dioxide and sodium oxide, and only reaches the requirement of sodium orthosilicate in content, and the molecular structure of the product is not the sodium orthosilicate in the chemical sense. The main defects are that the product is not mixed uniformly, the content is unstable, the dust is large in the production process, the dust is corrosive, contains silicon dioxide and pollutes the environment, and the production cost is high because sodium metasilicate and granular caustic soda are adopted for secondary processing.

The melting method is that sodium metasilicate and granular caustic soda are dissolved at high temp., then cooled and crystallized, and after breaking, sieving and drying, the original sodium silicate meeting the requirement of granularity is obtained. The main defects are that the process has poor working environment, high labor intensity of workers, low automation degree, low yield, low efficiency and high production cost. The production mode is discontinuous production, the humidity is high in summer weather, the production control is difficult, and the production cost is high due to the fact that sodium metasilicate and granular caustic soda are adopted for secondary processing.

One is a spray drying method, which utilizes caustic soda and liquid sodium silicate to adjust the mold, utilizes a high-speed atomizer to atomize the liquid into tiny liquid drops in a drying tower, dries the liquid drops at a high temperature of 400-. The product prepared by the process has fine granularity, is easy to absorb moisture, has large dust during packaging or use by customers, has corrosiveness, contains silicon dioxide, and has influence on human health.

The present invention has been made in view of this situation.

Disclosure of Invention

The technical problems to be solved by the invention are to overcome the defects of the prior art and provide a production process and production equipment of granular sodium orthosilicate so as to solve the technical problems of environmental pollution, low yield, low automation degree and high production cost in the production process of the granular sodium orthosilicate.

In order to solve the technical problems, the invention adopts the technical scheme that:

the invention provides a production process of granular sodium orthosilicate, which comprises the following steps:

(1) reacting quartz sand with caustic soda under the action of steam to obtain crude liquid sodium silicate;

(2) filtering the rough liquid sodium silicate to obtain refined liquid sodium silicate;

(3) refining the liquid sodium silicate and adjusting the mold to obtain liquid sodium orthosilicate;

(4) mixing the liquid sodium orthosilicate with baking soda and granulating to obtain granular sodium orthosilicate.

In the further scheme, in the step (1), the quartz sand is quartz sand containing 99.00-100% of silicon dioxide, the caustic soda is 50% of caustic soda, and the mass ratio of the quartz sand to the caustic soda is 1: 1.3-1.6.

In the further scheme, in the step (1), the steam pressure is 0.6-1.6MPa, the reaction temperature is 130-220 ℃, the reaction pressure is 0.7-1.2MPa, and the reaction time is 4-6 hours.

Wherein, in the step (1), the quartz sand is generally excessive by 3-5%, such as 36.5m in volume³The adding amount of the quartz sand in the reaction kettle is 16 to 18 tons per kettle, and the adding amount of 50 percent of caustic soda is 20 to 24 tons.

In the further scheme, in the step (2), the filtering pressure is 0-0.4MPa, the filtering temperature is 80-100 ℃, and the filter aid for filtering is quartz sand.

In the further scheme, in the step (2), the modulus of the refined liquid sodium silicate is 1.60-1.80, and the Baume degree is 62-64.

Wherein, in the step (2), the filter aid for filtration, namely quartz sand, is excessive. The quartz sand can filter out macromolecular and micromolecular impurities and colors, and other filter aids are not required to be added in the filtering process, so that the production cost is reduced, the production links are reduced, and the production efficiency is improved.

In the step (2), precoating is carried out for 2-3 hours in a circulating mode during filtration, and after sampling and clarification, filtration is finished.

In the further scheme, in the step (3), 50% of caustic soda is adopted for mold adjustment, and the mass ratio of the refined liquid sodium silicate to the 50% of caustic soda is 1: 1.0-1.2.

In the further scheme, in the step (3), the modulus of the liquid sodium orthosilicate is 0.47-0.57, the temperature is 80-90 ℃, and the Baume degree is 49-50 ℃.

In a further proposal, in the step (4), the baking soda is mixed with the liquid sodium orthosilicate in the form of 30 percent baking soda water solution, and the quality of the baking soda is 8 to 10 percent of the quality of the liquid sodium orthosilicate.

Further, in the step (4), the granulation is carried out in a dryer, liquid sodium orthosilicate is conveyed into the dryer through an injection pump, the injection pressure of the injection pump is 0.20-0.30MPa, the rotating speed of the dryer is 5-8 r/min, the mass ratio of the liquid sodium orthosilicate to the seed crystal in the dryer is 1:5-8, the temperature of drying air for drying is 300-400 ℃, and the discharge temperature of the dryer is 180-220 ℃.

Wherein the preparation process of the 30% sodium bicarbonate water solution comprises the following steps: dissolving sodium bicarbonate with water of 60-80 deg.C, and mixing with compressed air to obtain 30% sodium bicarbonate water solution. The 30% sodium bicarbonate solution and the liquid sodium orthosilicate are mixed evenly by compressed air.

In the further scheme, in the step (4), cooling is carried out after granulation, and the temperature of cooling air for cooling is 10-40 ℃.

The invention also provides a production device of granular sodium orthosilicate, which comprises:

the reaction kettle is used for reacting quartz sand and caustic soda to obtain crude liquid sodium silicate;

a feed inlet of the filter is connected with a discharge outlet of the reaction kettle and is used for filtering the rough liquid sodium silicate to obtain refined liquid sodium silicate;

the feed inlet of the batching tank is connected with the discharge outlet of the filter and is used for feeding refined liquid sodium silicate to adjust the mould to obtain liquid sodium orthosilicate and mixing the liquid sodium orthosilicate with sodium bicarbonate to obtain batching;

and a feed inlet of the granulation system is connected with a discharge outlet of the batching tank and is used for batching and granulating to obtain granular sodium orthosilicate.

Wherein, the reaction kettle is a roller reaction kettle.

In a further aspect, the apparatus further comprises:

and the clear liquid storage tank is connected with the filtering machine and the batching tank and is used for storing refined liquid sodium silicate and supplying the refined liquid sodium silicate to the batching tank.

In a further aspect, the apparatus further comprises:

the discharge port of the pulping tank is connected with the feed port of the reaction kettle and is used for mixing caustic soda and quartz sand and supplying a mixture of the caustic soda and the quartz sand to the reaction kettle;

the discharge port of the caustic soda tank is connected with the feed port of the pulping tank and is used for storing caustic soda and supplying the caustic soda to the pulping tank;

the sand warehouse is connected with the feed inlet of the pulping tank, and is used for storing quartz sand and supplying the quartz sand to the pulping tank;

the feeding port of the alkali mixing tank is connected with the reaction kettle, and the discharging port of the alkali mixing tank is connected with the filter and is used for receiving the rough liquid sodium silicate, facilitating parameter testing and supplying the rough liquid sodium silicate to the filter after the test is qualified;

and the control system is used for controlling the production process.

The control system is a DCS control system, the execution of equipment and the process is executed through the DCS control system, the DCS control system is adopted to set the operation data of the equipment, the flow state, the alarm information, the pressure, the temperature and the flow information of the equipment are dynamically displayed, and the DCS control system has the main temperature, pressure and flow recording function.

In a further aspect, a pelletizing system comprises:

the dryer is connected with the discharge port of the batching tank at the feed inlet and is used for batching, granulating and drying to obtain granular sodium orthosilicate;

the feed port of the screening machine is connected with the discharge port of the dryer and is used for screening granular sodium orthosilicate;

the cooling machine is connected with the discharge port of the sieving machine at the feed port and is used for cooling the granular sodium orthosilicate with qualified grain size;

a finished product bin, wherein a feed inlet of the finished product bin is connected with a discharge outlet of the cooler and is used for storing the cooled granular sodium orthosilicate;

the feed inlet of the pulverizer is connected with the discharge outlet of the sieving machine and is used for pulverizing the granular sodium orthosilicate with the screened grain diameter larger than the qualified grain diameter;

the fine powder bin is connected with the discharge port of the pulverizer and the discharge port of the screening machine respectively at the feed inlet thereof and is used for storing the granular sodium orthosilicate with the grain size smaller than the qualified grain size and the crushed granular sodium orthosilicate;

the seed crystal inlet of the dryer is connected with the discharge hole of the fine powder bin.

Wherein the dryer is a rotary dryer, and the liquid sodium orthosilicate can be sprayed and granulated in the rotary dryer.

In a further scheme, a discharge hole of the cooler is connected with a feed inlet of the finished product bin through an iron remover.

In a further scheme, the air inlet of the cooler is connected with the external atmosphere through a second blower and a dehumidifier, and the air outlet of the cooler is connected with the external atmosphere.

In a further scheme, an air outlet of the cooler is connected with the outside atmosphere through a second dust remover, and a discharge hole of the second dust remover is connected with a feed inlet of the fine powder bin.

In a further aspect, the granulation system further comprises:

the drying air duct is internally provided with a first circulating fan and a heating structure, an air outlet of the drying air duct is connected with an air inlet of the drying machine, the air inlet of the drying air duct is connected with the air outlet of the drying machine, the drying air duct is provided with a first exhaust port which can be opened and closed, and the first exhaust port is connected with the external atmosphere.

In a further scheme, the first exhaust port is connected with the outside atmosphere through a first dust remover, and the discharge port of the first dust remover is connected with the feed port of the fine powder bin.

In a further aspect, the granulation system further comprises:

the air inlet of the combustion furnace is connected with the outside atmosphere through a first air blower and is used for combusting combustible materials;

the flue gas flow channel is internally provided with a second circulating fan, the gas outlet of the flue gas flow channel is connected with the gas inlet of the combustion furnace, the gas inlet of the flue gas flow channel is connected with the gas outlet of the combustion furnace, the flue gas flow channel is provided with a second gas outlet which can be opened and closed, and the second gas outlet is connected with the outside atmosphere;

the first heat exchanger, the first flow channel of the first heat exchanger forms a flue gas air channel, the second flow channel of the first heat exchanger forms a drying air channel,

the first heat exchanger constitutes a heating structure.

In a further aspect, the granulation system further comprises:

a second heat exchanger;

the air inlet of the combustion furnace is connected with the outside atmosphere through an air inlet channel, the second air outlet is connected with the outside atmosphere through an air outlet channel, the air inlet channel forms a first channel of the second heat exchanger, and the air outlet channel forms a second channel of the second heat exchanger.

In a further scheme, a filter is arranged on the air inlet duct.

The granulation process of the liquid sodium orthosilicate comprises the following stages:

1. fluidization of seed crystals

Forming a bed layer with fluidization property on the solid particles in a rotary dryer; in the drier, the hot air and the particles are fully exchanged with heat through the material raising plate, so that the uniform and consistent drying effect can be realized.

2. Spray granulation

The slurry is pumped into a rotary dryer through an injection pump, the injection pressure is controlled to be 0.20-0.30MPa by adjusting the opening of a reflux valve, and the pressure is kept stable; atomized into fine liquid drops through an atomizing nozzle, sprayed on solid particles in a fluidized state, gradually grown through agglomeration and coating action, heated and evaporated by hot air to finally form dry particles, and discharged through the tail part of a dryer; the rotary dryer adopts frequency conversion control, and the frequency converter can be adjusted according to different yields; the injection amount is generally 3 to 4 tons/hour.

Granular sodium orthosilicate with a grain size larger than the qualified grain size (larger than 1.0mm) is crushed by an external crusher and returns to a rotary dryer together with granular sodium orthosilicate with a grain size smaller than the qualified grain size under a vibrating screen of a screening machine, so that the regulation of the grain diameter distribution is realized; the fine powder bin is used for storing fine powder, is provided with a weighing system and can be used for adjusting the material level of the system; the discharging temperature and granularity are controlled by controlling the ratio of material to liquid and the temperature of inlet and outlet air.

And the final dust removal of tail gas discharged by the rotary dryer is completed by the bag-type dust remover, and fine powder collected by the bag-type dust remover returns to the rotary dryer again through conveying equipment to provide seed crystals for the granulation process.

3. Air intake

The hydrogen is used as fuel to be mixed and combusted with air (the temperature is 120-140 ℃), the temperature is above 2000 ℃, the temperature is 500-600 ℃ after being mixed with returned circulating flue gas (the temperature is 200-260 ℃), the hydrogen amount and the air amount can be automatically adjusted through PID, and the temperature is kept stable. Heating process air at the temperature of 120-; the air outlet temperature is controlled at 120-; the opening degree of the flue gas circulating fan is 60-90%, the opening degree of the drying air fan is 50-70%, the fans are all controlled by frequency converters, and the system is kept in a micro negative pressure state.

4. Air exhaust

10-20% of the process air is exhausted after being dedusted by the deduster, and the rest of the process air is heated and then continuously circulated to dry the materials; returning the dust removed to the system for re-granulation; the dedusting fan is controlled by frequency conversion, and the opening degree is 50-80%.

5. Cooling of granular sodium orthosilicate

Cooling granular sodium orthosilicate to 50-60 ℃ by a cooler; the cooling fan and the cooling induced draft fan are controlled by frequency converters; the cooling air adopts a dehumidifier to remove the moisture in the air, so as to prevent the granular sodium orthosilicate from absorbing moisture and caking; the pipeline entering the finished product bin is provided with a high-temperature resistant strong magnetic iron remover, the magnetic force reaches 12000 gauss, the iron in the system is removed, and the content of granular sodium orthosilicate iron is reduced.

6. Sieving and pulverizing

The material discharged from the rotary dryer has a wider particle size range, firstly enters a vibrating screen for screening through a bucket elevator and a material separating valve, is crushed into particles with proper particle size (larger than 1.0mm) through a crusher, and returns to a fine powder bin through a conveyor; the opening of the material distributing valve can be adjusted within 0-100%, the amount of the material entering the sieving machine is adjusted, the amount of the finished product is controlled, and the material level of the system can be controlled.

And granules with qualified grain diameter of 0.25-1.0 mm under the vibrating screen are used as granular sodium orthosilicate with qualified grain diameter and sent into a finished product bin.

And returning the granules below the qualified particle size range (smaller than 0.25mm) under the vibrating screen to the fine powder bin.

Seed crystals are provided for the granulation process through the returned materials, and the particle diameter distribution in the granulation dryer and the adjustment of the retention time of the materials in the equipment are jointly realized.

7. Treatment of bag-type dust collector discharge

The fine powder separated from the bag-type dust collector returns to the fine powder bin through a conveying device and participates in the spray granulation process again. The bag-type dust collector adopts a high-temperature-resistant bag, can resist the temperature of more than 200 ℃, adopts PTFE, has high dust collection efficiency, and has the dust concentration of below 30mg/m 3.

After adopting the technical scheme, compared with the prior art, the invention has the following beneficial effects:

1. the granular sodium orthosilicate water-absorbing agent has the advantages that the granular sodium orthosilicate is obviously improved in granularity by adding the baking soda, the fine powder amount is reduced, the hardness of the granular sodium orthosilicate is improved, the drying time is shortened, and the moisture absorption tendency of the sodium orthosilicate is inhibited.

2. The granular sodium orthosilicate prepared by the production process and the production equipment has higher purity and content, is spherical particles, and has uniform granularity, good fluidity and large specific gravity.

3. The production equipment provided by the invention realizes the next step of producing granular sodium orthosilicate in a fully-closed state, adopts DCS control, has high automation control degree, also adopts linkage control, emergently stops when a fault occurs, avoids safety accidents, has few operators, saves labor cost, has low labor intensity, low maintenance amount and cost, and is energy-saving and environment-friendly.

4. The invention adopts the second heat exchanger to heat the air by utilizing the heat of the flue gas, thereby improving the temperature of the combustion air and reducing the energy consumption. And the second circulating fan is used for pumping the flue gas back to the combustion furnace to reuse the heat of the flue gas, so that the emission is reduced, and the energy conservation and emission reduction are facilitated.

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention, are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention without limiting the invention to the right. It is obvious that the drawings in the following description are only some embodiments, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:

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

FIG. 2 is a schematic view showing the structure of a part for producing an ingredient from a raw material in the production apparatus of the present invention;

FIG. 3 is a schematic view showing the structure of a part for producing granular orthosilicic acid from a batch in the production apparatus of the present invention.

In the figure: 1-caustic soda tank, 2-caustic soda pump, 3-belt conveyor, 4-pulping tank, 5-pulping pump, 6-reaction kettle, 7-alkali mixing tank, 8-filter pump, 9-filter, 10-batching tank, 11-batching pump, 12-injection tank, 13-injection pump, 14-mixing tank, 15-material transfer pump, 16-feeding flowmeter, 17-material return flowmeter, 18-pressure gauge, 19-feeding valve, 20-drier air inlet, 21-drier, 22-drier air outlet, 23-feeding screw, 24-fine powder bin, 25-first dust remover, 26-dust removal induced draft fan, 27-first circulating fan, 28-first heat exchanger, 29-air distribution chamber and 30-combustion furnace, 31-a combustor, 32-a first butterfly valve, 33-a second circulating fan, 34-a second heat exchanger, 35-a first air blower, 36-a filter, 37-a bucket elevator, 38-a material distributing valve, 39-a sieving machine, 40-a crushing machine, 41-a cooling machine, 42-a dehumidifier, 43-a second air blower, 44-a second butterfly valve, 45-a second dust remover, 46-a cooling induced draft fan, 47-an iron remover and 48-a finished product bin.

It should be noted that the drawings and the description are not intended to limit the scope of the inventive concept in any way, but to illustrate it by a person skilled in the art with reference to specific embodiments.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and the following embodiments are used for illustrating the present invention and are not intended to limit the scope of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example one

(1) Reacting quartz sand and caustic soda under the action of steam to obtain crude liquid sodium silicate, wherein the quartz sand is quartz sand containing 99.00-100% of silicon dioxide, the caustic soda is 50% of caustic soda, and the mass ratio of the quartz sand to the caustic soda is 1: 1.3; the steam pressure is 0.6MPa, the reaction temperature is 130 ℃, the reaction pressure is 0.7MPa, and the reaction time is 4 hours;

(2) filtering the crude liquid sodium silicate to obtain refined liquid sodium silicate, wherein the filtering pressure is 0.1MPa, the filtering temperature is 80 ℃, and the filter aid for filtering is quartz sand; the modulus of the refined liquid sodium silicate is 1.60, and the Baume degree is 62;

(3) adjusting the mould of the refined liquid sodium silicate to obtain liquid sodium orthosilicate, wherein the mould is adjusted by adopting 50% of caustic soda, and the mass ratio of the refined liquid sodium silicate to the 50% of caustic soda is 1: 1.0; the modulus of the liquid sodium orthosilicate is 0.47, the temperature is 80 ℃, and the Baume degree is 49 ℃;

(4) mixing liquid sodium orthosilicate and baking soda, and granulating to obtain granular sodium orthosilicate, wherein the baking soda is mixed with the liquid sodium orthosilicate in a form of 30% baking soda aqueous solution, and the mass of the baking soda is 8% of that of the liquid sodium orthosilicate; granulating in a dryer, wherein the injection pressure of an injection pump of the dryer is 0.20MPa, the rotating speed of the dryer is 5 r/min, the mass ratio of liquid sodium orthosilicate to crystal seeds in the dryer is 1:5, the drying air temperature of the dryer is 300 ℃, and the discharging temperature of the dryer is 180 ℃; after granulation, the mixture was cooled, and the cooling air temperature for cooling was 10 ℃.

Example two

(1) Reacting quartz sand and caustic soda under the action of steam to obtain crude liquid sodium silicate, wherein the quartz sand is quartz sand containing 99.00-100% of silicon dioxide, the caustic soda is 50% of caustic soda, and the mass ratio of the quartz sand to the caustic soda is 1: 1.5; the steam pressure is 1.0MPa, the reaction temperature is 180 ℃, the reaction pressure is 1.0MPa, and the reaction time is 5 hours;

(2) filtering the crude liquid sodium silicate to obtain refined liquid sodium silicate, wherein the filtering pressure is 0.2MPa, the filtering temperature is 90 ℃, and the filter aid for filtering is quartz sand; the modulus of the refined liquid sodium silicate is 1.70, and the Baume degree is 63;

(3) adjusting the mould of the refined liquid sodium silicate to obtain liquid sodium orthosilicate, wherein the mould is adjusted by adopting 50% of caustic soda, and the mass ratio of the refined liquid sodium silicate to the 50% of caustic soda is 1: 1.1; the modulus of the liquid sodium orthosilicate is 0.52, the temperature is 85 ℃, and the Baume degree is 49 ℃;

(4) mixing liquid sodium orthosilicate and baking soda, and granulating to obtain granular sodium orthosilicate, wherein the baking soda is mixed with the liquid sodium orthosilicate in a form of 30% baking soda aqueous solution, and the mass of the baking soda is 9% of that of the liquid sodium orthosilicate; granulating in a dryer, wherein the injection pressure of an injection pump of the dryer is 0.28MPa, the rotating speed of the dryer is 7 r/min, the mass ratio of liquid sodium orthosilicate to crystal seeds in the dryer is 1:6, the drying air temperature of the dryer is 350 ℃, and the discharging temperature of the dryer is 200 ℃; after granulation, the mixture was cooled, and the temperature of cooling air for cooling was 25 ℃.

EXAMPLE III

(1) Reacting quartz sand and caustic soda under the action of steam to obtain crude liquid sodium silicate, wherein the quartz sand is quartz sand containing 99.00-100% of silicon dioxide, the caustic soda is 50% of caustic soda, and the mass ratio of the quartz sand to the caustic soda is 1: 1.6; the steam pressure is 1.6MPa, the reaction temperature is 220 ℃, the reaction pressure is 1.2MPa, and the reaction time is 6 hours;

(2) filtering the crude liquid sodium silicate to obtain refined liquid sodium silicate, wherein the filtering pressure is 0.4MPa, the filtering temperature is 100 ℃, and the filter aid for filtering is quartz sand; the modulus of the refined liquid sodium silicate is 1.80, and the Baume degree is 64;

(3) adjusting the mould of the refined liquid sodium silicate to obtain liquid sodium orthosilicate, wherein the mould is adjusted by adopting 50% of caustic soda, and the mass ratio of the refined liquid sodium silicate to the 50% of caustic soda is 1: 1.2; the modulus of the liquid sodium orthosilicate is 0.57, the temperature is 90 ℃, and the Baume degree is 50 ℃;

(4) mixing liquid sodium orthosilicate and baking soda, and granulating to obtain granular sodium orthosilicate, wherein the baking soda is mixed with the liquid sodium orthosilicate in a form of 30% baking soda aqueous solution, and the mass of the baking soda is 10% of that of the liquid sodium orthosilicate; granulating in a dryer, wherein the injection pressure of an injection pump of the dryer is 0.30MPa, the rotating speed of the dryer is 8 r/min, the mass ratio of liquid sodium orthosilicate to crystal seeds in the dryer is 1:8, the drying air temperature of the dryer is 400 ℃, and the discharging temperature of the dryer is 220 ℃; after granulation, the mixture was cooled, and the temperature of cooling air for cooling was 40 ℃.

As shown in fig. 2 and 3, the embodiment of the present invention also introduces a production apparatus of granular sodium orthosilicate, comprising: the reaction kettle 6 is used for reacting quartz sand and caustic soda to obtain crude liquid sodium silicate; a filter 9, wherein a feed inlet of the filter 9 is connected with a discharge outlet of the reaction kettle 6 and is used for filtering the crude liquid sodium silicate to obtain refined liquid sodium silicate; a dosing tank 10, wherein a feed inlet of the dosing tank 10 is connected with a discharge outlet of the filter 9 and is used for adjusting the mould of the refined liquid sodium silicate to obtain liquid sodium orthosilicate and mixing the liquid sodium orthosilicate with sodium bicarbonate to obtain a dosing; and a feed inlet of the granulation system is connected with a discharge outlet of the batching tank 10 and is used for batching and granulating to obtain granular sodium orthosilicate. The corresponding production process flow is shown in figure 1.

Wherein, equipment still includes: a discharge port of the pulping tank 4 is connected with a feed port of the reaction kettle 6 and is used for mixing caustic soda and quartz sand and supplying a mixture of the caustic soda and the quartz sand to the reaction kettle 6; a discharge port of the caustic soda tank 1 is connected with a feed port of the pulping tank 4 and is used for storing caustic soda and supplying the caustic soda to the pulping tank 4; a discharge port of the sand warehouse is connected with a feed port of the pulping tank 4 and is used for storing quartz sand and supplying the quartz sand to the pulping tank 4; a feed inlet of the alkali mixing tank 7 is connected with the reaction kettle 6, a discharge outlet of the alkali mixing tank 7 is connected with the filter 9 and is used for receiving the rough liquid sodium silicate, facilitating parameter test and supplying the rough liquid sodium silicate to the filter 9 after the test is qualified; and the control system is used for controlling the production process. The control system is connected with a detector for detecting parameters (temperature, pressure, flow, liquid level, rotating speed, frequency and the like) in the production process, an adjusting component for adjusting the parameters (temperature, pressure, flow, liquid level, frequency, rotating speed and the like) in the production process, a valve for controlling the on-off of a flow channel and an air channel and the like, so that the control of automatic production is realized.

Specifically, caustic soda in a caustic soda tank 1 is supplied into a pulping tank 4 through a caustic soda pump 2, quartz sand in a sand bank is supplied into the pulping tank 4 through a belt conveyor 3, a mixture of caustic soda and quartz sand in the pulping tank 4 is supplied into a reaction kettle 6 through a pulping pump 5, crude liquid sodium silicate in an alkali mixing tank 7 is supplied into a filter 9 through a filter pump 8, ingredients in a batching tank 10 are supplied into a spraying tank 12 through a batching pump 11, ingredients in the spraying tank 12 can be supplied into a mixing tank 14 through a material transferring pump 15, ingredients in the spraying tank 12 can be partly supplied into a granulation system through a spraying pump 13, a feed flow meter 16 and a feed valve 19, and partly supplied back into the spraying tank 12 through a pressure gauge 18 and a return flow meter 17.

The production equipment provided by the invention realizes the next step of producing granular sodium orthosilicate in a fully-closed state, adopts DCS control, has high automation control degree, also adopts linkage control, emergently stops when a fault occurs, avoids safety accidents, has few operators, saves labor cost, has low labor intensity, low maintenance amount and cost, and is energy-saving and environment-friendly.

In this embodiment, the granulation system includes: a dryer 21, wherein a feed inlet of the dryer 21 is connected with a discharge outlet of the batching tank 10 and is used for batching, granulating and drying to obtain granular sodium orthosilicate; a sieving machine 39, wherein the feeding hole of the sieving machine 39 is connected with the discharging hole of the drying machine 21 and is used for sieving granular sodium orthosilicate; a feeding hole of the cooling machine 41 is connected with a discharging hole of the sieving machine 39 and is used for cooling the sieved granular sodium orthosilicate with qualified grain diameter; a finished product bin 48, wherein a feed inlet of the finished product bin 48 is connected with a discharge outlet of the cooler 41 and is used for storing the cooled granular sodium orthosilicate; a crusher 40, wherein the feed inlet of the crusher 40 is connected with the discharge outlet of the sieving machine 39 and is used for crushing granular sodium orthosilicate with the screened grain diameter larger than the qualified grain diameter; the fine powder bin 24 is connected with a discharge hole of the pulverizer 40 and a discharge hole of the sieving machine 39 respectively, and is used for storing the granular sodium orthosilicate and the crushed granular sodium orthosilicate which are sieved and have the grain size smaller than the qualified grain size; the seed crystal inlet of the dryer 21 is connected with the discharge hole of the fine powder bin 24.

Wherein, the granular sodium orthosilicate in the dryer 21 is supplied to the sieving machine 39 through the bucket elevator 37 and the material distributing valve 38, and the granular sodium orthosilicate in the fine powder bin 24 is supplied to the dryer 21 through the feeding screw 23.

According to the invention, through the arrangement, ingredients are granulated and dried into granular sodium orthosilicate by the dryer 21, the granular sodium orthosilicate is screened by the screening machine 39, and the screened granular sodium orthosilicate with qualified grain size is cooled into the granular sodium orthosilicate with proper temperature by the cooler 41, so that the target granular sodium orthosilicate is obtained and stored in the finished product bin 48; the screened granular sodium orthosilicate with the grain diameter larger than the qualified grain diameter is crushed into granular sodium orthosilicate with small grain diameter by a crusher 40, and the granular sodium orthosilicate is stored into a fine powder bin 24 to be used as a crystal seed to participate in the granulation and drying process; the screened granular sodium orthosilicate with the grain diameter smaller than the qualified grain diameter is also stored in the fine powder bin 24 to be used as a seed crystal to participate in the granulation and drying process.

In this embodiment, the discharge port of the cooler 41 is connected to the feed port of the finished product bin 48 through the iron remover 47. Wherein, the iron remover 47 is used for removing iron in the granular sodium orthosilicate, the feed inlet of the iron remover 47 is connected with the discharge outlet of the cooling machine 41, and the discharge outlet of the iron remover 47 is connected with the feed inlet of the finished product bin 48.

The invention removes iron in the granular sodium orthosilicate through the arrangement, thereby improving the quality of the granular sodium orthosilicate.

In this embodiment, the air inlet of the cooler 41 is connected to the outside atmosphere through the second blower 43 and the dehumidifier 42, and the air outlet of the cooler 41 is connected to the outside atmosphere.

The cooling air is the drying air through the arrangement, so that the moisture absorption of the granular sodium orthosilicate in the cooling process is avoided, and the quality of the granular sodium orthosilicate is improved.

In this embodiment, the air outlet of the cooler 41 is connected to the outside atmosphere via the second dust collector 45, and the discharge port of the second dust collector 45 is connected to the feed port of the fine powder bin. The second dust remover 45 is used for collecting the micro-particle sodium orthosilicate in the outlet air, the air inlet of the second dust remover 45 is connected with the air outlet of the cooler 41, and the air outlet of the second dust remover 45 is connected with the outside atmosphere.

The air outlet of the cooler 41 is connected with a second dust remover 45 through a second butterfly valve 44 for controlling the on-off of the air duct, and the second dust remover 45 is connected with the outside atmosphere through a cooling induced draft fan 46 for sucking air flow.

The invention avoids the influence of the micro-particle sodium orthosilicate discharged to the outside atmosphere on the environment through the arrangement, and simultaneously leads the collected micro-particle sodium orthosilicate to be used as the seed crystal to participate in the granulation drying process.

In this embodiment, the granulation system further includes: the drying air duct is internally provided with a first circulating fan 27 and a heating structure, the drying air duct air outlet is connected with the drier air inlet 20, the drying air duct air inlet is connected with the drier air outlet 22, the drying air duct is provided with a first exhaust port which can be opened and closed, and the first exhaust port is connected with the outside atmosphere. Wherein the flow direction of the drying air in the dryer 21 is opposite to the flow direction of the granular sodium orthosilicate in the dryer 21.

Wherein the first exhaust port is provided downstream of the first circulation fan 27 and the heating structure is provided downstream of the first exhaust port.

According to the invention, the drying treatment is ensured, and the energy recycling is realized, so that the energy is saved.

In this embodiment, the first exhaust port is connected to the outside atmosphere via a first dust collector 25, and the discharge port of the first dust collector 25 is connected to the feed port of the fine powder silo 24. Wherein, the first dust remover 25 is used for collecting the particle sodium orthosilicate in the outlet air, the air inlet of the first dust remover 25 is connected with the first exhaust port, the air outlet of the first dust remover 25 is connected with the outside atmosphere; the first dust remover 25 is connected with the outside atmosphere through a dust removal induced draft fan 26.

The invention avoids the influence of the micro-particle sodium orthosilicate discharged to the outside atmosphere on the environment through the arrangement, and simultaneously leads the collected micro-particle sodium orthosilicate to be used as the seed crystal to participate in the granulation drying process.

In this embodiment, the granulation system further includes: the combustion furnace 30, the air intake of the combustion furnace 30 couples to outside atmosphere through the first air blower, is used for supplying the combustible substance to burn; the flue gas flow channel is internally provided with a second circulating fan 33, the gas outlet of the flue gas flow channel is connected with the gas inlet of the combustion furnace 30, the gas inlet of the flue gas flow channel is connected with the gas outlet of the combustion furnace 30, the flue gas flow channel is provided with a second gas outlet which can be opened and closed, and the second gas outlet is connected with the outside atmosphere; the first heat exchanger 28, the first flow path of the first heat exchanger 28 constitutes the flue gas air duct, the second flow path of the first heat exchanger 28 constitutes the drying air duct, and the first heat exchanger 28 constitutes the heating structure.

Wherein, an air distribution chamber 29 is arranged at the upstream of the first heat exchanger 28, the first heat exchanger 28 is arranged at the upstream of the second circulating fan 33, and the second air outlet is arranged at the downstream of the second circulating fan 33.

According to the invention, the heat of combustion is exchanged to the drying air through the arrangement, so that the heating of the drying air is realized, and meanwhile, the energy is saved.

In this embodiment, the granulation system further includes: a second heat exchanger 34; an air inlet of the combustion furnace 30 is connected with the outside atmosphere through an air inlet duct, a second air outlet is connected with the outside atmosphere through an air outlet duct, the air inlet duct forms a first flow passage of the second heat exchanger 34, and the air outlet duct forms a second flow passage of the second heat exchanger 34.

Wherein, the second exhaust port is connected with a second heat exchanger 34 through a first butterfly valve 32 for controlling the on-off of the flow passage.

The preheating of the inlet air of the combustion furnace 30 is realized through the arrangement, so that the production efficiency is improved, and meanwhile, the energy is saved.

In this embodiment, the air inlet duct is provided with a filter 36. Wherein, the filter 36 is used for filtering the intake air; upstream of the filter there is a first blower 35,

in this embodiment, a burner 31 is disposed on the combustion furnace 30, an air inlet of the combustion furnace is disposed on the burner 31, and a combustible gas inlet is disposed on the burner 31. Wherein the combustible gas is hydrogen.

In conclusion, the granular sodium orthosilicate prepared by the production process and the production equipment has higher purity and content, is spherical particles, has uniform granularity and good fluidity and has high specific gravity. The process and the equipment adopt a DCS control system, realize continuous production, improve the yield, reduce the labor intensity, reduce the production cost, improve the production environment and achieve the effects of energy conservation and emission reduction.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.