A closed cycle sodium bicarbonate air stream dryer system and method of use

Abstract

The application provides a closed cycle sodium bicarbonate airflow dryer system, a screw feeder is connected to an airflow dryer, the bottom of the airflow dryer is connected with a drying gas pipeline, the top of the airflow dryer is connected with a cyclone separator, the bottom of the cyclone separator is connected with a powder flow cooler through a discharge pipeline, and the discharge pipeline is provided with a discharge valve; the top of the cyclone separator is connected to one side of the lower end of a condensation tower; the other side of the lower end of the condensation tower is connected to a circulating cooler through a condensation pipeline, and a circulating pump is arranged on the condensation pipeline; the condensation tower is connected with a wet dust removal tower, and the lower end of the wet dust removal tower is connected with a circulating pump; the wet dust removal tower is connected to the inlet of a drying fan, the drying fan is connected to a gas heater, and the gas heater is connected with the lower end of the airflow dryer. The application effectively solves the problem of sodium bicarbonate scabbing by using CO2 as drying gas, and the CO2 tail gas recovery saves cost, reduces carbon emission, and realizes no dust-containing tail gas emission, which has economic and environmental benefits.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of baking soda production, and particularly relates to a closed circulation baking soda airflow dryer system and a use method. BACKGROUND

[0002] Baking soda products are widely used, and are commonly used as bulking agents in food, can be used as food composite additives, and can be used for heat treatment of metal materials. A key technology in baking soda product production is drying treatment of baking soda, that is, drying wet baking soda (containing about 6%wt of water) produced into baking soda products (containing about 0.3%wt of water).

[0003] It is found through investigation and research that the current domestic baking soda airflow dryer system has problems such as baking soda scarring and dust in tail gas emission. INVENTION CONTENTS

[0004] Therefore, the present application aims to provide a closed circulation baking soda airflow dryer system and a use method to overcome the defects of the prior art, and solve the problems of baking soda scarring and dust in tail gas emission.

[0005] To achieve the above-mentioned purposes, the technical scheme of the present application is as follows:

[0006] A closed circulation baking soda airflow dryer system comprises a gas heater, an airflow dryer, a screw feeder, a cyclone separator, a powder flow cooler, a condensation tower, a circulation cooler, a wet dust removal tower and a drying fan.

[0007] The screw feeder is connected to the airflow dryer, and the screw feeder is used to supply material to the airflow dryer.

[0008] The bottom of the airflow dryer is connected to a drying gas pipeline, and the top of the airflow dryer is connected to the cyclone separator through a pipeline.

[0009] The bottom of the cyclone separator is connected to the powder flow cooler through a discharge pipeline, and the discharge pipeline is provided with a discharge valve; and the top of the cyclone separator is connected to the lower end of the condensation tower through a pipeline.

[0010] The other side of the lower end of the condensation tower is connected to the circulation cooler through a condensation pipeline, and a circulation pump is arranged on the condensation pipeline.

[0011] The condensation tower and the wet dust removal tower are connected through a production water pipeline, and the lower end of the wet dust removal tower is connected to a circulation pump.

[0012] The wet dust removal tower is connected to the inlet of the drying fan through a gas pipeline, the outlet of the drying fan is connected to the inlet of the gas heater through a pipeline, and the outlet of the gas heater is connected to the lower end of the airflow dryer.

[0013] Further, the bottom of the air flow dryer is provided with a wet material crushing device, the gas in the drying gas pipeline is CO2 gas; the bottom of the air flow dryer is provided with a discharge pipe.

[0014] Further, the condensing tower is provided with a liquid level meter, and the condensing tower is provided with a process water pipeline connected to the outside, and the process water pipeline is provided with a process water control valve.

[0015] Further, the lower end of the wet dust removal tower is connected with a circulating pump; the wet dust removal tower is provided with a liquid level meter, and the production water pipeline is provided with a production water control valve; the circulating pump is used to pump the production water in the wet dust removal tower into the condensing tower.

[0016] Further, the inlet of the drying fan is connected with a wet dust removal tower, the outlet of the drying fan is connected with a gas heater, and the outlet of the gas heater is connected with the lower end of the air flow dryer; the inlet of the drying fan is provided with a CO2 gas supplement control valve.

[0017] When the gas flow meter flow of the inlet pipeline of the drying fan is lower than the set value, the CO2 gas supplement control valve is opened to supplement the lost gas;

[0018] The outlet of the gas heater is provided with a CO2 thermometer, which can be adjusted by closing or opening the steam control valve when the temperature is too high or too low.

[0019] A use method of a closed circulation baking soda air flow dryer system, comprising the following steps

[0020] S1, sufficient contact; the drying hot gas in the air flow dryer is in sufficient contact with the wet material baking soda, the drying gas transmits heat to the baking soda material on one hand, and the water in the baking soda material evaporates and diffuses into the drying gas on the other hand, realizing the drying of the baking soda,

[0021] S2, material separation; the separation of the gas and the baking soda material is realized through a cyclone separator,

[0022] S3, material cooling; then the powder flow cooler cools the baking soda material to the product temperature, obtaining the baking soda product.

[0023] Further, in S2, the recirculated tail gas separated by the cyclone separator enters the condensing tower, and the recirculated tail gas is cooled by spraying process water, on one hand, the evaporated water in the air flow dryer is condensed in the condensing tower, on the other hand, the dust carried by the recirculated tail gas is washed away; the temperature of the recirculated drying gas in the condensing tower (8) is controlled by a circulating cooler, and the backflow temperature of the recirculated drying gas does not exceed 36℃.

[0024] Further, the CO2 gas flow meter arranged at the outlet of the wet dust removal tower can detect the flow of the recirculated gas, and the CO2 gas supplement control valve can be automatically started to supplement gas when the flow is lower than a set value; then the recirculated tail gas is sent into the gas heater by the drying fan, and the dried gas after heating regains the ability to dry baking soda, and enters a new round of closed cycle drying work.

[0025] Compared with the prior art, the closed cycle baking soda airflow dryer system and use method has the following advantages:

[0026] The closed cycle baking soda airflow dryer system and use method can be used for baking soda airflow drying, and provides technical support for baking soda drying process; the use of CO2 as drying gas effectively solves the problem of baking soda scarring, and is conducive to popularization and use in engineering projects; the closed cycle system recycles CO2 tail gas, saves cost, and has great economic benefits; the closed cycle system recycles CO2, reduces carbon emissions, and also realizes no dust-containing tail gas emission, and has great environmental benefits. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the present application, and the illustrative embodiments of the present application and their description serve the purpose of explaining the present application. The accompanying drawings do not constitute an inappropriate limitation on the present application. In the drawings:

[0028] Figure 1 It is a process flow diagram of the closed cycle baking soda airflow dryer system.

[0029] Explanation of reference signs:

[0030] 1, gas heater; 2, wet material crushing device; 3, airflow dryer; 4, screw feeder; 5, cyclone separator; 6, discharge valve; 7, powder flow cooler; 8, condensation tower; 9, circulating pump; 10, circulating cooler; 11, wet dust removal tower; 12, circulating pump; 13, drying fan; 21, CO2 gas supplement control valve; 22, process water control valve; 23, production water control valve; 24, CO2 gas flow meter; 25, steam control valve; 26, CO2 temperature meter. DETAILED DESCRIPTION

[0031] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0032] In the description of the present application, it is to be understood by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" and the like can be explicitly or implicitly included one or more. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0033] In the description of the present application, it is to be understood that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0034] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0035] As shown in Figure 1 A closed cycle sodium bicarbonate pneumatic dryer system, comprising a gas heater, a pneumatic dryer, a screw feeder, a cyclone separator, a powder flow cooler, a condensation tower, a circulating cooler, a wet dust removal tower and a drying fan; the screw feeder is communicated to the pneumatic dryer, and the screw feeder is used to feed the pneumatic dryer, the bottom of the pneumatic dryer is connected with a drying gas pipeline, the top of the pneumatic dryer is communicated with the cyclone separator through a pipeline, the bottom of the cyclone separator is connected with the powder flow cooler through a discharge pipeline, and the discharge pipeline is provided with a discharge valve; the top of the cyclone separator is connected to one side of the lower end of the condensation tower through a pipeline; the other side of the lower end of the condensation tower is connected to the circulating cooler through a condensation pipeline, and a circulating pump is arranged on the condensation pipeline; the condensation tower and the wet dust removal tower are communicated through a production water pipeline, and the lower end of the wet dust removal tower is connected with a circulating pump; the wet dust removal tower is communicated to the inlet of the drying fan through a gas pipeline, the outlet of the drying fan is communicated to the inlet of the gas heater through a pipeline, and the outlet of the gas heater is connected with the lower end of the pneumatic dryer.

[0036] Preferably, a wet material crushing device 2 is provided at the bottom of the airflow dryer 3, a screw feeder 4 is connected to the lower end of the airflow dryer 3, the bottom of the airflow dryer 3 is connected to a drying gas pipeline, the top of the airflow dryer 3 is connected to a cyclone separator 5, the bottom of the cyclone separator 5 is connected to a powder flow cooler 7, and the top of the cyclone separator 5 is connected to the lower end of a condensation tower 8; the wet material crushing device is located below the screw feeder; the gas in the drying gas pipeline is CO2 gas; and a discharge pipe is provided at the bottom of the airflow dryer.

[0037] Preferably, a circulating pump 9 is connected to the lower end of the condenser tower 8, and the circulating pump 9 is connected to a circulating cooler 10; the condenser tower 8 is equipped with a level gauge, and when the liquid level is higher than the set value, the process water control valve 22 is opened to discharge process water so that the liquid level of the condenser tower 8 is brought to a reasonable position; the cooling medium of the circulating cooler 10 is circulating water.

[0038] Preferably, the wet dust collector 11 is connected to a condenser tower 8, and a circulating pump 12 is connected to the lower end of the wet dust collector 11; the wet dust collector 11 is equipped with a level gauge, and when the liquid level is lower than the set value, the production water control valve 23 is opened to replenish production water and bring the liquid level of the wet dust collector 11 to a reasonable position; the circulating pump 12 pumps the production water in the wet dust collector 11 into the condenser tower 8 as needed.

[0039] Preferably, the inlet of the drying fan 13 is connected to a wet dust collector 11, and the outlet of the drying fan 13 is connected to a gas heater 1. The outlet of the gas heater 1 is connected to the lower end of the airflow dryer 3. The inlet of the drying fan 13 is equipped with a CO2 replenishment control valve 21. When the flow rate of the CO2 gas flow meter 24 in the inlet pipeline of the drying fan 13 is lower than the set value, the CO2 replenishment control valve 21 opens to replenish the lost gas. The outlet of the gas heater 1 is equipped with a CO2 thermometer 26. When its temperature is too high or too low, it can be adjusted by opening or closing the steam control valve 25.

[0040] like Figure 1 As shown, the method for drying baking soda using a closed-loop baking soda airflow dryer system described above involves the drying hot gas in the airflow dryer 3 coming into full contact with the wet baking soda material. The drying gas transfers heat to the baking soda material while the moisture in the baking soda material evaporates and diffuses into the drying gas, thus achieving the drying of the baking soda. Then, the gas and baking soda material are separated by a cyclone separator 5, and finally, the powder flow cooler 7 cools the baking soda material to the product temperature to obtain the baking soda product.

[0041] Specifically, the wet material crushing device 2 crushes the adhered materials to prevent blockage; the discharge pipe 14 is set to facilitate the discharge and maintenance of the bottom accumulated material; the drying gas is CO2 gas, which helps to inhibit the decomposition of baking soda and effectively solves the problem of baking soda scaling.

[0042] Preferably, the cyclone separator 5 separated recirculation tail gas enters the condensing tower 8, and the recirculation tail gas is cooled by spraying process water, on the one hand, the water evaporated in the air flow dryer 3 will be condensed in the condensing tower 8, and on the other hand, the dust carried by the recirculation tail gas will be washed; the temperature of the recirculation dry gas in the condensing tower 8 is controlled by the circulating cooler 10, and the backflow temperature of the recirculation dry gas should be as low as possible, and the temperature should not exceed 36℃, so as to have sufficient capacity to absorb the moisture of the baking soda material in the air flow dryer.

[0043] Preferably, the recirculation tail gas condensed by the condensing tower 8 will carry a small amount of dust and liquid droplets, and then the recirculation tail gas after condensation enters the wet dust removal tower 11 for washing to minimize the dust in the circulating gas, so as to avoid the problem of fouling in the closed circulation system.

[0044] Preferably, the recirculation tail gas treatment system composed of the condensing tower 8 and the wet dust removal tower 11 effectively treats the moisture and dust in the tail gas, without directly discharging the tail gas into the atmosphere, realizing the recycling use of the dry gas, on the one hand, the CO2 dry tail gas recovery saves cost and has great economic benefits, on the other hand, reduces carbon emissions, and also realizes no dust-containing tail gas emission, which has great environmental benefits.

[0045] Preferably, the CO2 gas flow meter 24 arranged at the outlet of the wet dust removal tower 11 can detect the flow of the recirculation gas, and the CO2 gas supplement control valve 21 can be automatically started for gas supplement when the flow is lower than the set value; then the recirculation tail gas is sent into the gas heater 1 by the dry fan 13, and the heated dry gas repossesses the ability to dry baking soda, and enters a new round of closed circulation drying work.

[0046] According to the above method, a closed circulation baking soda air flow dryer system is used, so that wet baking soda (moisture content 6%wt) can be dried into baking soda product (moisture content 0.3%wt).

[0047] A 50,000 tons / year baking soda production device application example is further illustrated.

[0048] The wet sodium bicarbonate filter cake with a flow rate of 6.65 t / h and a temperature of 65°C and a water content of 6%wt enters the pneumatic dryer 3 through the screw feeder 4; the drying gas CO2 with a flow rate of 29500 m3 / h and a temperature of 50°C is heated to 145°C by the gas heater 1, and is in full contact with the wet sodium bicarbonate filter cake in the pneumatic dryer 3, the drying gas transfers heat to the sodium bicarbonate material, and the water in the sodium bicarbonate material evaporates and diffuses into the drying gas, so that the sodium bicarbonate is dried, and the dried sodium bicarbonate has a flow rate of 6.27 t / h, a temperature of 80°C and a water content of 0.3%wt; after passing through the cyclone separator 5, the finished product of sodium bicarbonate enters the powder flow cooler 7 from the lower discharge valve 6 of the cyclone separator 5, and the sodium bicarbonate is cooled to 40°C to obtain the final product of sodium bicarbonate; the separated CO2 gas enters the condensation tower 8, and then the recirculation tail gas CO2 is cooled by spraying process water, on the one hand, the water evaporated in the pneumatic dryer 3 is condensed in the condensation tower 8, and on the other hand, the dust carried by the recirculation tail gas is washed away, the circulating pump 9 has a flow rate of 40 m3 / h, absorbs the heat of the recirculation drying gas, and takes away the heat of the recirculation drying gas through the circulating cooler 10, and the recirculation drying gas is cooled to 36°C; then the recirculation tail gas CO2 enters the wet dust removal tower 11 for washing to minimize the dust in the circulating gas to avoid the scaling problem in the closed circulation system, and the circulating pump 12 has a flow rate of 15 m3 / h; the recirculation drying gas after dust removal and cooling is sent into the gas heater 1 by the drying fan 13, the heated drying gas has the ability to dry sodium bicarbonate again, and enters a new round of closed circulation drying work. There is no sodium bicarbonate scaling problem during the operation, and no dust-containing tail gas is discharged.

[0049] The above merely describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0050] The above merely describes the preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A closed cycle soda stream dryer system, comprising a gas heater, a stream dryer, a screw feeder, a cyclone separator, a powder flow cooler, a condensing tower, a circulating cooler, a wet dust removal tower and a drying fan; The screw feeder is connected to the stream dryer, and the screw feeder is used to supply material to the stream dryer. The bottom of the stream dryer is connected to a drying gas pipeline, and the top of the stream dryer is connected to the cyclone separator through a pipeline. The bottom of the cyclone separator is connected to the powder flow cooler through a discharge pipeline, and the discharge pipeline is provided with a discharge valve. The top of the cyclone separator is connected to one side of the lower end of the condensing tower through a pipeline. The other side of the lower end of the condensing tower is connected to the circulating cooler through a condensing pipeline, and a circulating pump is arranged on the condensing pipeline. The condensing tower and the wet dust removal tower are connected through a production water pipeline, and the lower end of the wet dust removal tower is connected with a circulating pump. The wet dust removal tower is connected to the inlet of the drying fan through a gas pipeline, the outlet of the drying fan is connected to the inlet of the gas heater through a pipeline, and the outlet of the gas heater is connected to the lower end of the stream dryer. The gas in the drying gas pipeline is CO2 gas.

2. A closed cycle soda stream drier system as claimed in claim 1, wherein: The bottom of the stream dryer is provided with a wet material crushing device, and the bottom of the stream dryer is provided with a discharge pipe.

3. A closed cycle soda stream drier system as claimed in claim 1, wherein: The condensing tower is provided with a liquid level meter, and the condensing tower is provided with a process water pipeline connected to the outside. A process water control valve is arranged on the process water pipeline.

4. A closed cycle soda stream drier system as claimed in claim 1, wherein: The lower end of the wet dust removal tower is connected with a circulating pump; the wet dust removal tower is provided with a liquid level meter, the production water pipeline is provided with a production water control valve, and the circulating pump is used to pump the production water in the wet dust removal tower into the condensing tower.

5. A closed cycle soda stream drier system as claimed in claim 1, wherein: The inlet of the drying fan is connected with the wet dust removal tower, the outlet of the drying fan is connected with the gas heater, and the outlet of the gas heater is connected with the lower end of the stream dryer; the inlet of the drying fan is provided with a CO2 gas supplement control valve; When the gas flow meter flow of the drying fan inlet pipeline is lower than the set value, the CO2 gas supplement control valve opens to supplement the lost gas; The outlet of the gas heater is provided with a CO2 thermometer, which can be adjusted by closing or opening the steam control valve when the temperature is too high or too low.

6. The method of using a closed cycle sodium bicarbonate airstream dryer system according to any one of claims 1-5, wherein: The steps include: S1, sufficient contact; the drying hot gas in the stream dryer is in sufficient contact with the wet material soda, the drying gas transfers heat to the soda material, and the water in the soda material evaporates and diffuses into the drying gas, realizing the drying of the soda, S2, material separation; the cyclone separator is used to separate the gas and the soda material, S3, material cooling; then the powder flow cooler cools the soda material to the product temperature to obtain the soda product.

7. The use method of the closed cycle soda stream dryer system according to claim 6, wherein: In S2, the recycled tail gas separated by the cyclone separator enters the condensing tower, and the recycled tail gas is cooled by spraying process water. On the one hand, the water evaporated in the stream dryer is condensed in the condensing tower, and on the other hand, the dust carried by the recycled tail gas is washed away. The temperature of the recycled drying gas in the condensing tower (8) is controlled by the circulating cooler, and the backflow temperature of the recycled drying gas does not exceed 36℃.

8. The method of using a closed cycle soda stream drier system of claim 6, wherein: The CO2 gas flow meter arranged at the outlet of the wet dust removal tower can detect the flow of the recirculated gas, and the CO2 gas supplement control valve can be automatically started to supplement gas when the flow is lower than the set value; then the recirculated tail gas is sent into the gas heater by the drying fan, and the dried gas after heating regains the ability to dry the baking soda, and enters a new round of closed cycle drying work.

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