Summary of the Commissioning of the High-Efficiency Purification and Recovery System for Off-Gases from the Urea Granulation Tower at Yuntianhua with an Annual Production Capacity of 500,000 Tons

Thread Content

This post was last edited by Cuaili Yisu on 2019-1-28 at 10:27. I. Overview: The dust control projects for our company’s urea granulation towers (Phase I and Phase II), namely the new high-efficiency exhaust gas purification and recovery system for granulation towers, were successfully completed and put into operation on April 8, 2018, and May 4, 2018, respectively. This system was developed, designed, manufactured, and installed by Shanghai Jingye Environmental Protection Energy Technology Co., Ltd. It employs dry dust removal methods along with a fully automatic closed-loop dust recovery process, and it incorporates multiple patented technologies. Its purpose is to address the problems of excessive dust emissions and resource loss due to “tailing” that have plagued our company and the granulation tower industry for many years, as well as related environmental protection challenges. It represents the first such system in the granulation tower industry in Qinghai Province. Current operating results: the dust emission concentration at the outlet is less than 10 mg/Nm3, and there is no visible tailing. The expected goals were achieved, and satisfactory results were obtained. As of the time of writing, this project has been operating stably for 149 days now; it has withstood the challenges posed by high temperatures and humidity during the summer. In the performance evaluations conducted by the group company, the series of urea production units have managed to operate continuously for 100 days, achieving an unprecedented milestone! II. Results of Project Implementation: This renovation project involves the granulation towers in phases 1 and 2 of the factory; these towers have a diameter of 20 meters and an air handling capacity of 600,000 m3/h. The main pollutant in the exhaust gases from these granulation towers is valuable urea powder. The dust concentration in the unfiltered gases is generally between 150 and 300 mg/m3. Taking a urea granulation tower with an annual production capacity of 300,000 tons as an example, it generates approximately 720 to 1,440 tons of dust pollution and leads to resource waste each year. After the operation of the purification and recycling system was initiated, preliminary operational data showed that: 1) the trailing effect at the top of the granulation tower was completely eliminated, and according to engineering experience, the emission levels were between 3–8 milligrams per cubic meter, which represents a level of ultra-clean emissions. 2. The device can recover approximately 2 tons of urea per day, significantly reducing resource waste and generating additional economic benefits for the enterprise ； 3. After the modification, active control over the granulation yield and quality is achieved through the control of variable-frequency fans, which significantly reduces the instability in the quality and yield of the particles exiting the granulation tower – a problem that previously occurred due to external natural conditions such as climate, temperature, and humidity affecting the particles coming out of the tower. Stable production capacity will bring considerable economic benefits to the enterprise. Compared with the original water washing device, this apparatus completely solves several of the existing problems: 1. Low dust removal efficiency, with emissions exceeding standards ； 2. Severe tailing, with complaints from local residents ； 3. The filler is prone to clogging, resulting in poor ventilation and cooling effects, which affects production ； The exhaust gas purification and recovery system installed in the granulation tower is operating properly; the dust in the exhaust gases is discharged in compliance with environmental standards, which improves environmental quality and reduces harm to the surrounding environment. This facilitates safe and civilized production, ensures that economic and technical indicators are met, and leads to reduced consumption. Urea dust poses a direct threat to the health of workers in both the work areas and living areas; the corrosion and damage it causes to production equipment no longer occur, resulting in significant social and environmental benefits. The urea dust recovery function of the exhaust gas purification and recycling system meets the requirements of **environmental protection policies and the goal of building a harmonious society. It enhances corporate profitability, reduces environmental pollution, and brings about positive social, economic, and environmental benefits. This device is being used for the first time in large-scale fertilizer production in China. It represents the first pilot and demonstration project in the fertilizer industry where urea granulation tower off-gas recovery is employed on a large scale; the successful implementation of this project further enhances the company’s influence within the industry and across the country. If you are interested in the exhaust gas purification for urea granulation towers, feel free to follow the Shanghai Jingye Environmental Protection official account – we will deliver the latest updates to you as soon as they become available!