CN214039287U

CN214039287U - Ammonium nitrate particle drying system

Info

Publication number: CN214039287U
Application number: CN202023082904.3U
Authority: CN
Inventors: 张增房; 杨勇
Original assignee: Inner Mongolia Yidong Group Jiuding Chemical Co ltd
Current assignee: Inner Mongolia Yidong Group Jiuding Chemical Co ltd
Priority date: 2020-12-18
Filing date: 2020-12-18
Publication date: 2021-08-24
Anticipated expiration: 2030-12-18

Abstract

The utility model discloses a ammonium nitrate granule drying system, it includes technology steam purification unit, predrying air heater, first dry air heater, dry rotary drum, fluidized bed cooler and dry scrubber. The utility model makes the normal temperature air entering the pre-drying air heater enter the pre-drying section of the drying rotary drum after the process steam heat exchange, so that the temperature of the air entering the pre-drying section of the drying rotary drum is about 55 ℃, and the hot air is in direct current contact with the ammonium nitrate particles in the pre-drying section of the drying rotary drum, so that the particles are further cooled, crystallized and separated out water to form pores; cooling air leaving the fluidized bed cooler enters a first drying air heater, exchanges heat with process steam and then enters a drying section of the drying rotary drum, so that the temperature of the air entering the drying section of the drying rotary drum reaches 120 ℃; the temperature of air entering the drying drum is increased, the drying effect is improved, and the yield of products is further improved; meanwhile, the waste heat in the process steam is further utilized, and the energy loss is reduced.

Description

Ammonium nitrate particle drying system

The technical field is as follows:

the utility model relates to an equipment field is used in the ammonium nitrate production, especially relates to an ammonium nitrate granule drying system.

Background art:

at present, the ammonium nitrate particle drying process is as follows: the ammonium nitrate granules output by the granulation tower are sent to a feeding and conveying belt of the drying rotary drum through a conveying belt and then sent to the drying rotary drum. In the drying cylinder, hot air from a fluidized bed cooler gradually dries industrial granular porous ammonium nitrate in the drying cylinder, the drying cylinder is divided into a pre-drying section and a drying section, and in the pre-drying section, the air and the materials flow in the same direction; in the drying section, the air flows counter-currently to the material. And conveying the finished product discharged from the drying rotary drum to the bucket elevator through a discharging conveying belt of the drying rotary drum and a feeding belt of the bucket elevator.

Materials from the bucket elevator can be conveyed through a screening machine, qualified products are conveyed to a fluidized bed cooler after screening, and unqualified particle products which are too large and too small are returned to a remelting tank; or directly sent to the fluidized bed cooler through a three-way chute without passing through a sieving machine.

The product with the temperature of about 80 ℃ entering the fluidized bed cooler is cooled to about 30 ℃ by air, the fluidized bed cooler is composed of two material trays fixed on a pore plate, and atmospheric air with the temperature of 23 ℃ is fed by a fluidized bed blower and passes through the two material trays from bottom to top. The cooling air leaving the fluidized bed cooler is sent into the drying drum by the fluidized bed induced draft fan. The process has the following disadvantages: the temperature of the drying air entering the drying drum is low, the drying effect is not ideal, and the product yield is low.

In addition, the gas ammonia and the dilute nitric acid from the nitric acid device are subjected to neutralization reaction to generate an ammonium nitrate solution, the generated ammonium nitrate solution enters a flash evaporation tank of the reactor for flash evaporation, process steam is separated from the ammonium nitrate solution, the ammonium nitrate solution is discharged from the bottom, the process steam is directly condensed by a washing process condenser and enters a washing process condensate tank, and the process condensate is sent out of a boundary area to the water treatment device. But the temperature of the process steam is above 150 ℃, and a large amount of heat energy is wasted due to direct condensation treatment.

The utility model has the following contents:

for improving energy utilization, improve drying effect, and then improve the yield of granule ammonium nitrate, the utility model aims to provide an ammonium nitrate granule drying system.

The utility model discloses by following technical scheme implement: the ammonium nitrate particle drying system comprises a process steam purification unit, a pre-drying air heater, a first drying air heater, a drying rotary drum, a fluidized bed cooler and a drying washer;

a process steam outlet of a neutralization steam washing tower of the process steam purification unit is respectively connected with a process steam inlet of the pre-drying air heater and a process steam inlet of the first drying air heater; the process steam condensate outlet of the pre-drying air heater and the process steam condensate outlet of the first drying air heater are both connected with the condensate tank inlet;

the hot air outlet of the pre-drying air heater is connected with the hot air inlet of the pre-drying section of the drying rotary drum, and the hot air outlet of the pre-drying section of the drying rotary drum is connected with the air inlet of the drying washer;

and a cooling air outlet of the fluidized bed cooler is connected with a cooling air inlet of the first drying air heater, a cooling air outlet of the first drying air heater is connected with a drying section hot air inlet of the drying rotary drum, and a drying section hot air outlet of the drying rotary drum is connected with an air inlet of the drying washer.

Further, the process steam purification unit comprises a reactor flash tank, a venturi scrubber and a neutralization steam scrubber; and a process steam outlet of the flash tank of the reactor is connected with a process steam inlet of the venturi scrubber, and a process steam outlet of the venturi scrubber is connected with a process steam inlet of the medium steam scrubbing tower.

The utility model has the advantages that: the utility model makes the normal temperature air entering the pre-drying air heater enter the pre-drying section of the drying rotary drum after further heat exchange of the process steam, so that the temperature of the air entering the pre-drying section of the drying rotary drum is about 55 ℃, and the hot air is in concurrent contact with the ammonium nitrate particles in the pre-drying section of the drying rotary drum, so that the particles are further cooled, crystallized and separated out water to form pores; cooling air leaving the fluidized bed cooler enters a first drying air heater, further exchanges heat with process steam and then enters a drying section of the drying rotary drum, so that the temperature of the air entering the drying section of the drying rotary drum reaches 120 ℃; the temperature of air entering the drying drum is increased, the drying effect is improved, and the yield of products is further improved; meanwhile, the waste heat in the process steam is further utilized, and the energy loss is reduced.

Description of the drawings:

FIG. 1 is a schematic diagram of a system for drying ammonium nitrate granules.

The system comprises a process steam purification unit 1, a reactor flash evaporation tank 1-1, a Venturi scrubber 1-2, a neutralizing steam scrubber 1-3, a pre-drying air heater 2, a first drying air heater 3, a drying rotary drum 4, a fluidized bed cooler 5, a drying scrubber 6 and a condensate tank 7.

The specific implementation mode is as follows:

as shown in fig. 1, the ammonium nitrate granule drying system comprises a process steam purification unit 1, a pre-drying air heater 2, a first drying air heater 3, a drying drum 4, a fluidized bed cooler 5 and a drying scrubber 6; the process steam purification unit 1 comprises a reactor flash evaporation tank 1-1, a Venturi scrubber 1-2 and a neutralization steam scrubber 1-3; a process steam outlet of the flash tank 1-1 of the reactor is connected with a process steam inlet of the venturi scrubber 1-2, and a process steam outlet of the venturi scrubber 1-2 is connected with a process steam inlet of the neutralization steam scrubber 1-3; the process steam outlet of the neutralization steam washing tower 1-3 is respectively connected with the process steam inlet of the pre-drying air heater 2 and the process steam inlet of the first drying air heater 3; the process steam condensate outlet of the pre-drying air heater 2 and the process steam condensate outlet of the first drying air heater 3 are both connected with the inlet of the condensate tank 7;

a hot air outlet of the pre-drying air heater 2 is connected with a hot air inlet of a pre-drying section of the drying rotary drum 4, and a hot air outlet of the pre-drying section of the drying rotary drum 4 is connected with an air inlet of the drying washer 6;

the cooling air outlet of the fluidized bed cooler 5 is connected with the cooling air inlet of the first drying air heater 3, the cooling air outlet of the first drying air heater 3 is connected with the hot air inlet of the drying section of the drying rotary drum 4, and the hot air outlet of the drying section of the drying rotary drum 4 is connected with the air inlet of the drying washer 6.

Description of the technical process:

the granulated ammonium nitrate granules enter a drying rotary drum 4 through a conveying belt, and the drying rotary drum 4 is dried in two sections.

In the pre-drying section, normal temperature clean air enters the pre-drying section after heat exchange (the temperature is about 55 ℃) with process steam from the process steam purification unit 1 through the pre-drying air heater 2, and is in concurrent contact with ammonium nitrate particles in the pre-drying section, so that the ammonium nitrate particles are further cooled, crystallized and separated out water to form pores;

in the drying section, cooling air from the fluidized bed cooler 5 passes through the first drying air heater 3, exchanges heat with process steam from the process steam purification unit 1 (the temperature is about 120 ℃) and then enters the drying section to be in countercurrent contact with ammonium nitrate particles in the drying section, so that the ammonium nitrate particles are dried until the moisture is qualified. The process steam is condensed into condensate after being used for heat utilization by the pre-drying air heater 2 and the first drying air heater 3 and enters a condensate tank 7 of the washing process.

Conveying the ammonium nitrate granules to a vibrating screen for screening by a belt and a bucket elevator, returning oversized unqualified granules to a re-dissolving tank for dissolving, and re-granulating; the acceptable granules are sent to a fluidized bed cooler 5. In the fluidized bed cooler 5, clean cooling air from the ammonia evaporation process is subjected to heat exchange with ammonium nitrate granules by four fans, the ammonium nitrate granules are cooled to about 30 ℃, and air heated in the cooling process is sent to the first dry air heater 3 for use. The used waste air dried in the drying drum 4 is introduced into a dry scrubber 6, washed and discharged to the atmosphere. Ammonium nitrate particles enter the wrapping rotary drum through the conveying belt, are sprayed with the wrapping agent and then are conveyed to finished product packaging and warehousing.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The ammonium nitrate particle drying system is characterized by comprising a process steam purification unit, a pre-drying air heater, a first drying air heater, a drying rotary drum, a fluidized bed cooler and a drying washer;

2. A ammonium nitrate granule drying system of claim 1 wherein the process steam purification unit comprises a reactor flash drum, a venturi scrubber and a neutralization steam scrubber; and a process steam outlet of the flash tank of the reactor is connected with a process steam inlet of the venturi scrubber, and a process steam outlet of the venturi scrubber is connected with a process steam inlet of the medium steam scrubbing tower.