scholarly journals Application and performance evaluation of desulfurization wastewater spray drying technology

2020 ◽  
Vol 143 ◽  
pp. 02029
Author(s):  
Zhang Shanshan ◽  
Wang Renlei ◽  
Tang Guorui ◽  
Dai YU
Keyword(s):  
Spray Drying ◽  
Flue Gas ◽  
Unit Load ◽  
Air Preheater ◽  
Mass Fractions ◽  
Denitrification Reactor ◽  
And Performance ◽  
Drying Technology ◽  
Gas Volume ◽  
Desulfurization Wastewater

In order to realize zero discharge of desulfurization wastewater, spray drying technology of desulfurization wastewater was used in 2x330MW unit of a power plant. Its principle was to use a rotary atomizer for atomization,and a part of hot flue gas was drawn from the SCR denitrification reactor and air preheater into the drying tower, the heat was used to evaporate the desulfurization wastewater in a spray drying tower. The salt in the waste water was mixed with the dust, which was collected and removed by the electric dust remover. Then the water vapor was mixed with the flue gas and finally enters the desulfurization tower.The field test was carried out under the condition that the unit load was 100% and the amount of desulfurization wastewater treated was 5.1m3/h.The results showed that the hot smoke gas volume of drying tower was about 64896m3/h, The smoke temperature at the inlet and outlet of the drying tower were 335℃ and 205℃ respectively,the moisture content of drying products was only 0.05%. The content of HCl in the flue gas at the inlet and outlet of the drying tower were 55mg/L and 195mg/L respectively, the mass fractions of Cl removal and Cl volatilization in desulfurization wastewater were 87.7% and 12.3% respectively. The increase of Cl content in the dried products had little effect on the utilization of fly ash.

scholarly journals The Causes Analysis of the Air Preheater and Performance Blocking Evaluation of the Measures on the SCR De-NOx Unit

2019 ◽  
Vol 118 ◽  
pp. 03056
Author(s):  
Su Pan ◽  
Pengfeng Yu ◽  
Linbo Liu ◽  
Jing Han ◽  
Xiao Shen
Keyword(s):  
Flue Gas ◽  
Differential Pressure ◽  
Control Measures ◽  
Gas Temperature ◽  
Air Preheater ◽  
Environment Temperature ◽  
Ammonium Bisulfate ◽  
And Performance ◽  
Exhaust Gas Temperature ◽  
Ammonia Injection

In order to solve the problem of abnormal rise of the differential pressure of the revolving air preheater on 300MW unit, we analysed the causes of abnormal rise of the differential pressure of the air preheater and evaluated performances of control measures, through historical data mining and on-site inspection of the unit. The results show that, with the gradual decrease of environment temperature with the decrease of the exhaust gas temperature, the ashes in flue gas are bound by acid liquid produced by condensation of flue gas, and the adhesion areas of the ammonium bisulfate produced in the denitration process are enlarged. However the original set ash blowing pressure can no longer satisfy the requirements of the air preheater, giving rise to the differential pressure of the air preheater on both sides to rise. The reason of the higher differential pressure of the unilateral air preheater is that the large ammonia injection amount, leading to the increases of ammonia escape of the denitrification system. So the side of the air on preheater ammonium bisulfate type blockage is more serious. After the Measures of Adjusting distribution coefficient of ammonia supply valve on both sides, increasing the dust blowing frequency and pressure of the air preheater, the differential pressure of air preheater on both sides are close to the consistent. The decrease amplitude of the differential pressure of the air preheater on 280MW is about 300-500Pa.

scholarly journals Simulation Study on Centrifugal Spray Evaporation Characteristics and Process Optimization of Desulfurization Wastewater

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 837
Author(s):  
Ning Zhao ◽  
Yongxin Feng ◽  
Debo Li ◽  
Zongkun Li
Keyword(s):  
Flue Gas ◽  
Gas Flow ◽  
Droplet Evaporation ◽  
Advanced Treatment ◽  
Axial Distance ◽  
Liquid Ratio ◽  
Evaporation Time ◽  
Liquid Discharge ◽  
Drying Technology ◽  
Desulfurization Wastewater

As an advanced treatment of desulfurization wastewater, centrifugal spray drying technology, which can achieve a zero liquid discharge target, has attracted wide attention and great interest in recent years. However, the results of previous studies were based on the laboratory-scale centrifugal spray dryer. In order to study the evaporation characteristics of desulfurization wastewater and the parameter optimization of the dryer, the evaporation model of wastewater droplets was established. The effects of parameters such as the angle of the deflectors, gas–liquid ratio and atomizer speed on droplet evaporation were studied by numerical simulation. The results show that with the increase in the angle of the deflectors, the swirl effect of flue gas flow field is more obvious and the time and axial distance required for the complete evaporation of the droplets are shorter. Reducing the gas–liquid ratio will make the average evaporation time longer. Moreover, a higher atomizer speed is helpful for the evaporation of the droplets. The optimum gas–liquid ratio and rotational speed are found to be 9300 m3/Nm3 and 16,000 rpm, respectively.

scholarly journals Numerical Investigation on the Evaporation Performance of Desulfurization Wastewater in a Spray Drying Tower without Deflectors

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1022
Author(s):  
Debo Li ◽  
Ning Zhao ◽  
Yongxin Feng ◽  
Zhiwen Xie
Keyword(s):  
Spray Drying ◽  
Droplet Size ◽  
Flow Rate ◽  
Flue Gas ◽  
Gas Flow ◽  
Initial Temperature ◽  
Gas Temperature ◽  
Gas Flow Rate ◽  
Complete Evaporation ◽  
Desulfurization Wastewater

The desulfurization wastewater evaporation technology with flue gas has been widely applied to dispose of desulfurization wastewater. This paper investigates the effect of flue gas flow rate and temperature, wastewater flow rate and initial temperature, and droplet size on the evaporation performance of the desulfurization wastewater in a spray drying tower without deflectors. The results show that the flue gas flow rate and temperature affect the evaporation performance of desulfurization wastewater. The larger flow rate and higher temperature of flue gas correspond to the faster evaporation speed and the shorter complete evaporation distance of the wastewater droplet. Decreasing the flow rate and increasing the initial temperature of the desulfurization wastewater is advantageous to enhance the evaporation speed and shorten the complete evaporation distance of the wastewater droplet. Reducing the droplet size is beneficial to improve the evaporation performance of the desulfurization wastewater. The orthogonal test results show that the factors affecting droplet evaporation performance are ranked as follows: flue gas flow rate > wastewater flow rate > flue gas temperature > wastewater initial temperature > droplet size. Considering the evaporation ratio and the complete evaporation distance, the optimal setting is 14.470 kg/s for flue gas flow rate, 385 °C for flue gas temperature, 0.582 kg/s for wastewater flow rate, 25 °C for wastewater initial temperature, and 60 μm for droplet size. These studied results can provide valuable information to improve the operational performance of the desulfurization wastewater evaporation technology with flue gas.

Design and Performance Analysis of Air Pre heater for Water Tube Boiler to improve its Efficiency

2021 ◽  
pp. 01-06
Author(s):  
V. Karthikeyan ◽  
M. Sambathkumar ◽  
K. Arulkumar
Keyword(s):  
Heat Transfer ◽  
Air Temperature ◽  
Flue Gas ◽  
Transfer Coefficients ◽  
Air Preheater ◽  
Software Application ◽  
Heat Transfer Coefficients ◽  
Performance Requirements ◽  
Specific Performance ◽  
And Performance

Air preheater is a heat transfer surface in which air temperature is raised by transferring heat from other media such as flue gas which is coming from boiler exhaust. The paper presents the design of regenerative –air preheater to designed to meet specific performance requirements, using the software application CFD (Computational Fluid Dynamics) / CADD. An analytical study was planned to find out the various heat transfer performance parameters like outlet and inlet air temperature of the air preheater and the boiler, Pressure drop inside the Air preheater and the boiler heat transfer coefficients, heat transfer rate, overall heat transfer coefficient and Velocity of the air and flue gas also Conduction and convection modes of heat transfer were found. These heat transfer parameters are critical in designing and functioning of the air Preheater and to calculate the efficiency of the boiler.

TEKNOLOGI PENANGANAN EMISI GAS DARI INSINERATOR SAMPAH KOTA

2019 ◽  
Vol 11 (2) ◽  
Author(s):  
Prasetiyadi Prasetiyadi ◽  
Wiharja Wiharja ◽  
Sri Wahyono
Keyword(s):  
Fly Ash ◽  
Pressure Drop ◽  
Spray Drying ◽  
Flue Gas ◽  
Bag Filter

Proses pembakaran sampah kota melalui insinerator akan menghasilkan uap panas yang bisa dimanfaatkan  untuk membangkitkan energi listrik, akan tetapi pada proses ini juga menghasilkan output berupa flue gas yang didominasi oleh partikel (fly ash) dan gas beracun seperti: HCl, SO2, NOx, HF, Hg, Cd dan Dioxin. Sebelum dibuang ke udara bebas, flue gas tersebut harus diolah agar memenuhi baku mutu lingkungan. Teknologi penanganan partikel dan gas polutan tersedia dan dapat dibuat dengan berbagai kapasitas. Untuk menangani flue gas dari insinerator sampah digunakan Quencher untuk menekan laju pembentukan kembali dioksin dan furan setelah proses pembakaran,  Spray Drying Absorption (SDA) untuk mengikat gas asam dan  logam berat serta bag filter untuk menangkap partikel. Selain itu digunakan ID Fan dan Cerobong Asap untuk pengatasi pressure drop yang terjadi akibat pengoperasian peralatan APC dan melepas ke udara.

Synthesis and Performance of Cathode Material Li3V2(PO4)3/C by Spray Drying and Carbothermal Method (SDATM)

2009 ◽  
Vol 24 (2) ◽  
pp. 349-352 ◽  
Author(s):  
Feng YU ◽  
Jing-Jie ZHANG ◽  
Yan-Feng YANG ◽  
Guang-Zhi SONG
Keyword(s):  
Cathode Material ◽  
Spray Drying ◽  
Carbothermal Method ◽  
And Performance

scholarly journals Numerical Study toward Optimization of Spray Drying in a Novel Radial Multizone Dryer

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1233
Author(s):  
Umair Jamil Ur Rahman ◽  
Artur Krzysztof Pozarlik ◽  
Thomas Tourneur ◽  
Axel de Broqueville ◽  
Juray De Wilde ◽  
...  
Keyword(s):  
Spray Drying ◽  
Droplet Size ◽  
Separation Efficiency ◽  
Numerical Study ◽  
Three Dimensional ◽  
Droplet Size Distribution ◽  
Vortex Chamber ◽  
Temperature Pattern ◽  
Multiphase Model ◽  
Drying Technology

In this paper, an intensified spray-drying process in a novel Radial Multizone Dryer (RMD) is analyzed by means of CFD. A three-dimensional Eulerian–Lagrangian multiphase model is applied to investigate the effect of solids outlet location, relative hot/cold airflow ratio, and droplet size on heat and mass transfer characteristics, G-acceleration, residence time, and separation efficiency of the product. The results indicate that the temperature pattern in the dryer is dependent on the solids outlet location. A stable, symmetric spray behavior with maximum evaporation in the hot zone is observed when the solids outlet is placed at the periphery of the vortex chamber. The maximum product separation efficiency (85 wt %) is obtained by applying high G-acceleration (at relative hot/cold ratio of 0.75) and narrow droplet size distribution (45–70 µm). The separation of different sized particles with distinct drying times is also observed. Smaller particles (<32 µm) leave the reactor via the gas outlet, while the majority of big particles leave it via the solids outlet, thus depicting in situ particle separation. The results revealed the feasibility and benefits of a multizone drying operation and that the RMD can be an attractive solution for spray drying technology.

Numerical simulation and field test study of desulfurization wastewater evaporation treatment through flue gas

2014 ◽  
Vol 70 (7) ◽  
pp. 1285-1291 ◽  
Author(s):  
Jia-jia Deng ◽  
Liang-ming Pan ◽  
De-qi Chen ◽  
Yu-quan Dong ◽  
Cheng-mu Wang ◽  
...  
Keyword(s):  
Field Test ◽  
Flue Gas ◽  
Cfd Simulation ◽  
Electrostatic Precipitator ◽  
Negative Impact ◽  
Positive Impact ◽  
Field Tests ◽  
Gas Temperature ◽  
Simulation Results ◽  
Desulfurization Wastewater

Aimed at cost saving and pollution reduction, a novel desulfurization wastewater evaporation treatment system (DWETS) for handling wet flue gas desulfurization (WFGD) wastewater of a coal-fired power plant was studied. The system's advantages include simple process, and less investment and space. The feasibility of this system has been proven and the appropriate position and number of nozzles, the spray droplet size and flue gas temperature limitation have been obtained by computational fluid dynamics (CFD) simulation. The simulation results show that a longer duct, smaller diameter and higher flue gas temperature could help to increase the evaporation rate. The optimal DWETS design of Shangdu plant is 100 μm droplet sprayed by two nozzles located at the long duct when the flue gas temperature is 130 °C. Field tests were carried out based on the simulation results. The effects of running DWETS on the downstream devices have been studied. The results show that DWETS has a positive impact on ash removal efficiency and does not have any negative impact on the electrostatic precipitator (ESP), flue gas heat exchanger and WFGD. The pH values of the slurry of WFGD slightly increase when the DWETS is running. The simulation and field test of the DWETS show that it is a feasible future technology for desulfurization wastewater treatment.

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