CN217110221U

CN217110221U - Ammonium chloride drying and cooling system

Info

Publication number: CN217110221U
Application number: CN202220778891.3U
Authority: CN
Inventors: 张庆磊; 张海滨; 孟庆松; 赵平杰; 陈际显; 玄继贤; 李鑫昌; 刘涛
Original assignee: Shandong Tianli Energy Co ltd
Current assignee: Shandong Tianli Energy Co ltd
Priority date: 2022-04-06
Filing date: 2022-04-06
Publication date: 2022-08-02
Anticipated expiration: 2032-04-06

Abstract

The utility model relates to an ammonium chloride drying and cooling system belongs to ammonium chloride production technology technical field. Ammonium chloride drying and cooling system includes fluidized bed drying machine, powder flow cooler and tail gas processing line, the high temperature drying section discharge end of fluidized bed drying machine passes through the feed end that the powder flow cooler was connected to the hopper lifting machine, the air inlet end of fluidized bed drying machine is connected with air supply arrangement, the air intake of tail gas processing line is connected to the tail gas air outlet of fluidized bed drying machine, the air-out end of tail gas processing line returns the air inlet end that is connected to air supply arrangement. The utility model discloses an ammonium chloride drying and cooling system uses powder to flow the cooling zone that the cooler replaces traditional fluidized bed, and the air supply arrangement of fluidized bed is sent back to tail gas after tail gas treatment line will be handled, forms closed circulation, realizes the cyclic utilization of dry wind, reduces exhaust emissions.

Description

Ammonium chloride drying and cooling system

Technical Field

The utility model relates to an ammonium chloride production technology technical field, concretely relates to ammonium chloride drying and cooling system.

Background

The ammonium chloride is colorless crystal or white crystalline powder, has hygroscopicity, and is mainly derived from byproduct of soda production by combined soda production method. After the suspension containing ammonium chloride is centrifugally dewatered, the moisture content of the obtained wet ammonium chloride is generally 5-8%. The water content of the qualified industrial ammonium chloride product is less than or equal to 1.0 percent, and the ammonium chloride with high water content is easy to agglomerate to influence the use. Therefore, industrial ammonium chloride needs to be dried before leaving the factory, and the transportation and use requirements can be met after moisture is removed.

Currently, the most efficient and commonly used process for ammonium chloride drying is the thermal drying process. Namely, the heating action of the heat source is utilized to heat the ammonium chloride material and the moisture in the material together, the steam equilibrium partial pressure of the moisture in the material is increased, the steam pressure difference between the moisture and the surrounding atmosphere is increased, and a driving force is formed to diffuse the moisture from the material to the surrounding atmosphere, so that the drying purpose is achieved. The drying process based on the thermal drying principle can quickly dehydrate the materials and simultaneously can also increase the temperature of the materials.

Ammonium chloride is very hygroscopic. In a closed space, the high-temperature materials easily enrich and condense water vapor in the surrounding atmosphere, and are finally absorbed by the ammonium chloride materials again, so that the water content of the ammonium chloride dry materials is increased again, and caking is easily caused to influence transportation and use. Therefore, in order to avoid material agglomeration, a cooling process is required after the thermal drying process to lower the temperature of the dried product.

Currently, fluidized bed drying/cooling processes are commonly used for drying and cooling ammonium chloride. The fluidized bed is a static device with a box structure, and materials are fed from one end and discharged from the other end. The front section of the fluidized bed is a drying section, the rear section of the fluidized bed is a cooling section, and the drying and cooling functions are completed by one device. The fluidized bed drying/cooling process is basically characterized in that the fluidized bed is used for forming the material into a boiling state, the material is directly contacted with fluidized air and violently moves, and high-efficiency heat transfer and mass transfer are carried out. The technology is mature, has long application history and wide application range. However, there are also certain disadvantages:

(1) in order to make a large amount of materials form a boiling state, the flow and the pressure of the fluidized air are large, the size of a matched fan is large, and the power consumption is high.

(2) The larger the fluidization air quantity is, the more the formed tail gas quantity is, the more difficult the pollutants in the tail gas are to be purified, the larger the size, investment and occupied area of the tail gas purifying equipment is, and the higher the maintenance cost is.

(3) The production flexibility of the fluidized bed is low. The fluidizing air speed is not allowed to have large fluctuation due to the requirement of material fluidization. If the low-load production is carried out, the required air volume and the discharged tail gas volume are basically consistent with those of the full load, so that the operation cost of unit capacity is increased.

(4) The material cooling effect is greatly influenced by the ambient temperature, so the material cooling effect is greatly influenced by seasons. Especially in high temperature environments in summer, it is difficult to cool the material to a lower temperature.

Disclosure of Invention

For solving the problem among the prior art, the utility model discloses a dry cooling system of ammonium chloride has been designed, can improve the cooling efficiency after the material drying, reduces seasonal influence, reduces the intake, reduces the energy consumption, reduces exhaust emissions.

The utility model adopts the technical proposal that: ammonium chloride drying and cooling system includes fluidized bed drying machine, powder flow cooler and tail gas processing line, the high temperature drying section discharge end of fluidized bed drying machine passes through the feed end that the powder flow cooler was connected to the hopper lifting machine, the air inlet end of fluidized bed drying machine is connected with air supply arrangement, the air intake of tail gas processing line is connected to the tail gas air outlet of fluidized bed drying machine, the air-out end of tail gas processing line returns the air inlet end that is connected to air supply arrangement. The powder flow cooler is used for replacing a cooling section of the fluidized bed dryer, the consumption of fluidized air is greatly reduced, and the dried tail gas is returned to the air inlet end of the fluidized bed dryer after being treated by the tail gas treatment line, so that the large-scale emission of the tail gas is avoided.

Further, the heat exchanger of powder flow cooler is connected with soft water cooling device, soft water cooling device package piece soft water tank, circulating pump and soft water cooler, the soft water tank passes through the circulating pump and the heat exchanger of circulating line connection powder flow cooler, conventional recirculating cooling water system is connected to soft water cooling device's soft water cooler. Powder flows the cooler and is noble equipment, uses conventional refrigeration cycle water to cause the equipment corrosion easily, causes big loss, adds soft water cooling device after, uses the soft water to carry out the heat transfer cooling to powder flow the cooler, reduces recirculated cooling water and flows the corruption of cooler to the powder, and conventional recirculated cooling water is connected to soft water cooling device, cools off the cooling to the soft water.

Furthermore, the powder flow cooler is connected with a compressed air pipeline, and the compressed air pipeline is provided with a plurality of compressed air inlets on the side wall of the powder flow cooler bin body. The compressed air is blown in to make the material in the powder flow cooler in a semi-fluidized state, so as to prevent the material from bridging in the bin body.

Furthermore, the discharge end of the hopper elevator is provided with two discharging pipelines, one of the discharging pipelines is connected with the powder flow cooler, and the other discharging pipeline is provided with a material returning and discharging valve and is connected to the feed end of the fluidized bed dryer through the scraper conveyor. Carry out the returning charge through scraper conveyor to the feed end of fluidized bed drying machine, reduce the viscidity of feeding, reduce the gluing to equipment.

Further, the feed end of fluidized bed dryer is connected with the compounding feeder, the compounding feeder is provided with two feed inlets, is wet material feed inlet and feed back feed inlet respectively, the material return feed inlet of blendor is connected to scraper conveyor's discharge end, the feed inlet of fluidized bed dryer is connected to the discharge gate of blender.

Further, the tail gas treatment line includes cyclone, sack cleaner and the draught fan that connects gradually through the pipeline, and the pipeline connection fluidized bed drying machine's of cyclone front end tail gas air outlet, the pipeline connection air supply arrangement of draught fan rear end.

Further, air supply arrangement includes pipe connection's air-blower and gas heater, the pipe connection air-blower's of draught fan rear end air inlet end, gas heater's air-out end is connected the air inlet end of fluidized bed drying machine.

Furthermore, a tail gas purifying and cooling device is arranged on a connecting pipeline between the tail gas treatment line and the air supply device. The tail gas purification and cooling device is used for removing ammonia gas in the tail gas and cooling.

Furthermore, the powder flow cooler is provided with a material level meter, the discharge end of the powder flow cooler is provided with a powder outflow material valve, and the control ends of the material returning discharge valve and the powder outflow material valve are respectively connected with an electric actuator. The powder flow cooler controls the material level in the bin body through a discharge valve at the discharge end, and ensures that the material in the bin body can completely embed the heat exchanger. The material returning and discharging valve is used for controlling the material returning amount.

Compared with the prior art, the utility model discloses an ammonium chloride drying and cooling system's that the patent designed progress part lies in:

1. the powder flow cooler is adopted to replace a cooling section of the traditional fluidized bed drying process, a large amount of fluidized air is not needed, an additional matched fan is not needed, and the power consumption can be greatly reduced;

2. because no fluidized air is needed, the tail gas formed by the powder flow cooler is very small in quantity, the tail gas is easy to purify, the size, the investment and the occupied area of tail gas purifying equipment are very small, and the maintenance cost is low;

3. the powder flow cooler can adjust the flow of the cooling medium according to the production load, the operation cost of unit productivity can be adjusted along with the load, and the production elasticity is high;

4. the powder flow cooler does not need ambient air as a cooling medium, and the cooling effect is only influenced by the temperature and the flow of circulating water. The sensitivity to ambient temperature is reduced compared to fluidized bed cooling. Although the influence of the season cannot be completely avoided, the sensitivity to the season is much lower than that of the fluidized bed. In high-temperature weather in summer, the cooling effect can still be improved by adjusting the flow of the circulating water;

5. after the powder flow cooler is added into the soft water cooling device, the soft water is used for carrying out heat exchange and cooling on the powder flow cooler, so that the corrosion of circulating cooling water on the powder flow cooler is reduced, and the operation and maintenance cost of equipment is reduced;

6. the fluidized bed drying tail gas is purified and then returned to the air inlet device, thereby realizing the closed cycle of the tail gas, reducing the tail gas emission and avoiding the environmental pollution.

Drawings

FIG. 1 is a schematic diagram showing the constitution of an ammonium chloride drying and cooling system.

In the figure, a fluidized bed dryer 1, a powder flow cooler 2, a bucket elevator 3, a scraper conveyor 4, a cyclone dust collector 5, a bag dust collector 6, an induced draft fan 7, a tail gas purification and cooling device 8, an air blower 9, a gas heater 10, a mixing feeder 11, a feeding end 12, a discharging end 13, an air inlet 14, an air outlet 15, a powder outflow material valve 21, a soft water tank 22, a soft water circulating pump 23, a soft water cooler 24, a compressed air pipeline 25 and a material returning and discharging valve 31 are arranged.

Detailed Description

The invention will be further described with reference to the accompanying drawings and specific embodiments. The technical solutions in the embodiments of the present invention are clearly and completely described, and the described embodiments are only some embodiments of the present invention, not all embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative effort belong to the protection scope of the present invention.

As shown in fig. 1, the present invention relates to an embodiment of an ammonium chloride drying and cooling system, which comprises a fluidized bed dryer 1, a powder flow cooler 2 and a tail gas treatment line. The discharge end 13 of the high-temperature drying section of the fluidized bed dryer 1 is connected with the feed inlet of the powder flow cooler 2 through the hopper lifter 3.

The fluidized bed dryer 1 in this embodiment may be an internally heated fluidized bed having a heat exchange tube therein, or may be a normal fluidized bed having no heat exchange tube. A material mixing feeder 11 is arranged at a material feeding end 12 of the material mixing feeder 11, and the material mixing feeder 11 is provided with two material feeding holes which are a wet material feeding hole and a material returning feeding hole respectively. An air inlet 14 of the fluidized bed dryer 1 is connected with an air supply device, the air supply device is composed of a blower 9 and a gas heater 10 which are connected through pipelines, and after drying air is sent to the gas heater 10 through the blower 9 and heated, formed high-temperature air is sent to a fluidized bed. Under the action of high-temperature hot air, the materials are in a boiling state in the fluidized bed, are gradually dehydrated and dried, and are discharged from the discharge end 13 of the fluidized bed.

The dried material is transported to the next process by the hopper elevator 3. The discharge end of the hopper elevator 3 is provided with two discharging pipelines, one of the discharging pipelines is connected with the powder flow cooler 2, the other discharging pipeline is provided with a material returning discharge valve 31 and is connected to a material returning feed inlet of the material mixing feeder 11 at the feed end of the fluidized bed dryer 1 through the scraper conveyor 4, the returned dry materials and wet materials are mixed in the mixer and enter the fluidized bed together, and the viscosity of the wet materials is reduced. An electric actuator is connected to the material returning and discharging valve 31, so that the material returning amount can be conveniently controlled.

The powder flow cooler 2 is a vertical bin body, and a plurality of groups of heat exchangers are arranged in layers in the bin body. The heat exchanger can be plate type or tube type, the ammonium chloride material to be cooled is in shell pass, the cooling medium is in the interlayer or tube in the plate, and the material and the cooling medium indirectly exchange heat through the heat exchanger. The heat exchanger of the powder flow cooler 2 is connected to a soft water cooling device using soft water as a cooling medium. The soft water cooling device comprises a block-packed soft water tank 22, a soft water circulating pump 23 and a soft water cooler 24, wherein the soft water tank 22 is connected with the heat exchanger of the powder flow cooler 2 through the soft water circulating pump and a circulating pipeline to cool materials in the bin body of the powder flow cooler 2. The soft water cooler 24 of the soft water cooling device is connected with a conventional circulating cooling water system to cool the soft water subjected to heat exchange.

In order to ensure sufficient contact area between the material in the powder flow cooler 2 and the cooling medium, all heat exchangers need to be buried in the material. For this purpose, a bin body of the powder flow cooler 2 is provided with a level gauge, and a powder outflow valve 21 with an electric actuator is connected to a discharge end of the level gauge. The material level of the material in the bin body of the powder flow cooler 2 is effectively controlled by a material level meter and a powder outflow material valve 21.

When the powder flow cooler is in a working state, a large amount of materials are filled in the bin body, and the heat exchanger is buried in the materials. Meanwhile, the high-temperature material is in contact with the ambient atmosphere in the conveying process from the fluidized bed to the powder flow cooler, so that the water vapor near the material is easily enriched. In order to prevent the materials from dewing due to moisture absorption in the cooling process, the enriched water vapor and the materials need to be separated in time. Therefore, in order to prevent the bridging of the materials in the bin body and discharge the water vapor carried in the gaps of the materials in time, compressed air needs to be introduced in the working process of the powder flow cooler. The compressed air pipeline 25 of one powder flow cooler is provided with a plurality of compressed air inlets which are positioned on the side wall of the powder flow cooler bin body. Compressed air may be introduced into the powder stream cooler from a plurality of inlets. Under the impact action of compressed air, the material is in a semi-fluidized state in the powder flow cooler and is not easy to bridge. The water vapor enriched in the material gaps in the bin body is taken away by compressed air and is discharged from the top of the powder flow along with the continuously introduced gas to form cooling tail gas. Compared with a fluidized bed, the sectional area of the powder flow is small, so that the air quantity required for forming a semi-fluidized state of the material is small. Thus, the powder stream has a lower amount of cooling off-gas. Usually, an independent dust removing device and a fan are arranged, and the air is discharged after dust removal and purification. Because the amount of tail gas is small, the specification of dust removal equipment matched with the powder flow cooler is also small.

The tail gas air outlet 15 of the fluidized bed dryer 1 is connected with a tail gas treatment line, the air outlet 15 is connected with an air inlet of the tail gas treatment line, and an air outlet end of the tail gas treatment line returns to be connected with an air inlet end of an air supply device. The tail gas treatment line comprises a cyclone dust collector 5, a bag-type dust collector 6 and an induced draft fan 7 which are sequentially connected through pipelines, the pipeline at the front end of the cyclone dust collector 5 is connected with a tail gas outlet 15 of the fluidized bed dryer 1, and the pipeline at the rear end of the induced draft fan 7 is connected with an air inlet end of an air blower 9 of an air supply device. Meanwhile, a tail gas purification and cooling device 8 is arranged on a connecting pipeline of the draught fan 7 and a blower 9 of the air supply device.

The tail gas purification and cooling device 8 can adopt the prior art and generally comprises a dust removal washing tower, a tail gas condensation tower and an ammonia removal tower. The dust removal washing tower is used for removing residual part of dust in the tail gas after the bag-type dust remover, and simultaneously can preliminarily reduce the temperature of the tail gas; the tail gas condensing tower has the functions of cooling the tail gas, reducing the temperature of the tail gas, condensing moisture in the tail gas, separating the moisture and carrying wet air, and removing part of ammonia gas in the tail gas; the function of the ammonia removal tower is to remove ammonia deeply.

The drying tail gas generated by the fluidized bed dryer 1 comes from the waste gas formed after the heat exchange between the fluidized air in the drying section and the materials. The dry tail gas is firstly used for removing ammonium chloride dust by a cyclone dust collector 5 and a bag-type dust collector 6. Then, the tail gas is sent to a tail gas purification cooling device 8 under the action of an induced draft fan 7, and residual dust, ammonia gas and most of water vapor carried in the tail gas are removed. The purified tail gas is returned to the inlet of the blower 9 and is recycled as the drying air. The tail gas treatment process enables the fluidized bed drying air to form closed cycle, almost no tail gas is discharged, and the atmospheric pollution can be greatly reduced.

The above description is only for the preferred embodiment of the present invention, and should not be taken as limiting the scope of the invention, which is defined by the appended claims and the description of the invention.

Claims

1. The utility model provides a dry cooling system of ammonium chloride, a serial communication port, dry cooling system of ammonium chloride includes fluidized bed drying machine, powder flow cooler and tail gas processing line, the high temperature drying section discharge end of fluidized bed drying machine passes through the feed end that the powder flow cooler was connected to the hopper lifting machine, the air inlet end of fluidized bed drying machine is connected with air supply arrangement, the air intake of tail gas processing line is connected to the tail gas air outlet of fluidized bed drying machine, the air-out end return connection to air supply arrangement's air inlet end of tail gas processing line.

2. The system of claim 1, wherein the heat exchanger of the powder flow cooler is connected with a soft water cooling device, the soft water cooling device comprises a soft water tank, a circulating pump and a soft water cooler, the soft water tank is connected with the heat exchanger of the powder flow cooler through the circulating pump and a circulating pipeline, and the soft water cooler of the soft water cooling device is connected with a circulating cooling water system.

3. The system as claimed in claim 2, wherein the powder flow cooler is connected with a compressed air pipeline, and the compressed air pipeline is provided with a plurality of compressed air inlets on the side wall of the powder flow cooler chamber body.

4. The system of claim 3, wherein the discharge end of the hopper elevator is provided with two discharge lines, one of which is connected to the powder flow cooler and the other of which is provided with a material return discharge valve and is connected to the feed end of the fluidized bed dryer through a scraper conveyor.

5. The ammonium chloride drying and cooling system as claimed in claim 4, wherein the feed end of the fluidized bed dryer is connected with a mixing feeder, the mixing feeder is provided with two feed inlets, namely a wet feed inlet and a return feed inlet, the discharge end of the scraper conveyor is connected with the return feed inlet of the mixer, and the discharge outlet of the mixing feeder is connected with the feed inlet of the fluidized bed dryer.

6. The ammonium chloride drying and cooling system of claim 5, wherein the tail gas treatment line comprises a cyclone dust collector, a bag-type dust collector and an induced draft fan which are sequentially connected through pipelines, the pipeline at the front end of the cyclone dust collector is connected with a tail gas outlet of the fluidized bed dryer, and the pipeline at the rear end of the induced draft fan is connected with an air supply device.

7. The ammonium chloride drying and cooling system of claim 6, wherein the air supply device comprises an air blower and a gas heater which are connected through a pipeline, the pipeline at the rear end of the induced draft fan is connected with the air inlet end of the air blower, and the air outlet end of the gas heater is connected with the air inlet end of the fluidized bed dryer.

8. The ammonium chloride drying and cooling system as claimed in claim 7, wherein a tail gas purifying and cooling device is disposed on a connection pipeline between the tail gas treatment line and the air supply device.

9. The system of claim 8, wherein the powder flow cooler is provided with a level indicator, the discharge end of the level indicator is provided with a powder discharge valve, and the control ends of the material return discharge valve and the powder discharge valve are respectively connected with an electric actuator.