Environmental protection issues of natural gas rotary kilns
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In the initial stage, the company used conventional electric heating ovens for drying, based on practical considerations. However, an issue arose during use: the drying cycle was too long (over 12 hours), requiring overnight drying to reduce energy consumption. To this end, the company switched to using rotary kilns for drying. However, the environmental protection authorities now require that: 1. The exhaust gases generated by natural gas combustion be collected and treated before being released into the atmosphere; the levels of dust and sulfur dioxide in these exhaust gases must meet the standard limits specified in the \"Notice on Issuing Further Measures to Strengthen Air Pollution Control.\" The levels of nitrogen oxides must comply with the emission concentration limits for gas-fired boilers as listed in Table 2 of GB13271-2014 \"Emission Standards for Air Pollutants from Boilers.\" I would like to ask the experts: 1. Since the scope of such rectifications is relatively small, can the company carry out the rectifications on its own? 2. During the rectification process, natural gas is collected and treated before being released into the atmosphere – how is this specifically carried out (where is it collected? Drain height? Are there qualified third-party construction firms? ) 3. For the final environmental acceptance, it requires approval from the environmental protection agency. Are there also specialized third-party testing agencies for detecting gas emissions, just as there are such agencies for wastewater treatment? I hope everyone can help, thank you.
The company in question originally used electric heaters for drying, but now it uses gas rotary dryers; I assume that the materials you need to dry are mostly in the form of solid blocks or powders. Using flue gas from natural gas combustion to dry solid materials in a rotary kiln presents not only the issue of ensuring that nitrogen oxides, sulfur oxides, and other pollutants in the flue gas are emitted within permissible levels, but also the issue of ensuring that dust is emitted at acceptable levels. I was in contact with a company that used rotary kilns to dry materials, and it once faced serious problems related to excessive dust emissions. The flue gas emerging from the rotary furnace contains a large amount of dust. Initially, bag filters were used for dust removal, but even two sets of such filters were unable to handle the high-volume flue gas, resulting in high operation and maintenance costs. Later, an electrostatic precipitator was added downstream of the bag filter, but during the 0.5 to 1 hour period of backwashing of the bag filter, the backwash air carried a large amount of dust, causing the vapor concentration at the outlet of the electrostatic precipitator to exceed the standard by about 3 times. Finally, a multi-factor swirl parent-child separator was added to the exhaust pipeline of the electrostatic dust removal equipment to handle the excessive dust in the flue gas that escaped the electrostatic dust removal system, thereby enabling the flue gas from the rotary drying furnace to be discharged in compliance with standards. Please pay close attention to the flue gas emissions from the gas-drying rotary furnace. For technical information related to multi-factor cyclone parent-child separators, please visit the HaiChuan Chemical Industry Forum using the direct link http://bbs.hcbbs.com/thread-1354813-1-1.html for more details.