Development status of bag dust collector in power plant
The boiler dust collector in the power plant has experienced the process of electrostatic precipitator from a dry cyclone dusting, a multi tube cyclone, a water film dust removal and a electrostatic precipitator. At present, with the increasing emphasis on environmental protection and environmental protection, and the localization and service life of filter bags, the dust removal of the boiler tail section of thermal power plants has returned to the trend of bag dust removal.
With the further improvement of science and technology, the categories of bag filters in China are basically complete. The type and performance of their products basically meet the needs of boiler dedusting. Its technological development is mainly reflected in the following aspects.
(1) improvement of the structure form of bag type dust collector. The bag filter is developing from small single room structure to multi chamber structure. The filter area has been developed from several square meters to tens of thousands of square meters, and the specifications are bigger and bigger. The bag type dust removal technology with compact and lightweight structure has been developed by adopting the unit combination form of the filter bag rack as a whole.
(2) technological progress of the ash cleaning system. The dust cleaning system is the digestive organ of the bag type dust collector, and the operation effect of the bag type dust collector depends to a great extent on the ash cleaning mechanism and its control system. At present, the injection pressure of high and low pressure pulse valves has been designed from 0.5~0.7MPa to 0.15~0.25MPa by adopting international standards. A large low-pressure long bag pulse technology has been developed on the basis of the original high pressure small hole pulse based on pulse jet bag filter. The control system program develops from timing to constant resistance, and develops from open loop control to closed loop control. The grade of control instrument is developed from relay logic program controller to single board microcomputer, single-chip microcomputer, programmable controller and multi-function computer controller. The function of the control system is from two ground control, state display, fault alarm to sub room leak detection, data processing, and printing report.
(3) the development and application of auxiliary ash cleaning technology, such as pre coating technology, preload technology, sound wave cleaning technology and so on.
(4) the technology of filter material and filter bag has been improved to a great extent.
(5) the manufacturing technology and production equipment of the bag filter are gradually on the right track, and a complete process line is set up.
(6) gradually built up the software data of bag filter, and formulated the national, professional and enterprise three level standards, which played a positive role in the manufacture of dust remover, the development and acceptance of new products.
In 1980s and early 90s, China has been in several small coal-fired units used in the bag type dust collector, because of the limitation of conditions, not persist, the main reason is that the overall level of bag type dust collector is still relatively backward, reliable performance of large pulse blow bag dust collector has not developed, filter it is not suitable for our country's coal-fired power plants need good strength, high temperature resistance, corrosion resistance, long service life; domestic pulse valve does not pass, the service life is short; the processing and installation of other components is not very good, plus the bag dust to recognize and use the experience is not enough, so it appears "burn bag", "paste bag", "leak" and "death", "ash poor" phenomenon.
In the past ten years, the development of bag type dust collector is very fast, especially the big bag type dust collector, the development of new material and new pulse valve, the bag type dust collector is more safe and reliable, not only than the efficiency of the electric precipitator is high, but also affected by the characteristics of dust and flue gas components are small, I believe that in the near future, the performance of large pulse bag type dust collector reliable can be extended and applied in coal-fired power plant.