LI Jianlong¹，ZHONG Jianfang¹，CHEN Jianwu²，YANG Bin²，HUANG Hong¹，HUANG Shan¹，YOU Da¹，MA Zhifei¹

Abstract

Objective In order to improve the “dead zone” and overall poor cleaning effect of the box filter cartridge during the cleaning process， the influence of the spraying distance and opening length of the slot nozzle on the cleaning performance of the filter cartridge is analyzed to achieve more effective cleaning effect and provide guidance for engineering practice.

Methods Construct a box filter cartridge dust collector system and simplify it based on the system. Then， perform grid independence， simulation， and experimental verification to analyze the effects of different blowing distances and slot lengths on the flow field and sidewall pressure values inside the filter cartridge. Using the peak sidewall pressure and coefficient of variation as technical indicators to evaluate the dust cleaning performance， design four types of slot nozzles with lengths and widths of 75 mm×6 mm，50 mm×6 mm，38 mm×6 mm， and 30 mm×6 mm， and explore the effects of blowing distances and different slot lengths on the pressure distribution on the inner wall of the filter cartridge.

Results and Discussion This article explores the optimal cleaning parameters of a slot nozzle for a square filter cartridge， and investigates the effects of blowing distance and slot length on the blowing intensity and uniformity of the filter cartridge. The main conclusions are as follows. The airflow ejected from the slot nozzle converges at the bottom of the filter cartridge and maintains sustained high pressure in the middle-lower section， thereby enhancing dust cleaning efficiency in this region. For rectangular filter cartridges， the jet intensity first increases then decreases with increasing blowing distance， reaching optimal performance at 200 mm with a peak intensity of 2，076 Pa. At this distance， the sidewall pressure distribution demonstrates improved uniformity， evidenced by a coefficient of variation of 0. 27. Similarly， jet intensity exhibits a non-monotonic relationship with slit length， peaking at 38 mm with maximum intensity of 2，261 Pa， though with slightly reduced uniformity （coefficient of variation：0. 41）. As the gap length decreases， the blowing intensity shows a trend of first increasing and then decreasing. When the gap length is too large， the sprayed airflow is too concentrated， the cleaning range is limited， and the total amount of suction airflow is insufficient， resulting in difficulty in cleaning the top of the filter cartridge； When the slit length is too small， it leads to a decrease in the air flow rate and airflow intensity of a single nozzle.

Conclusion By reasonably controlling the spraying distance and slot length， it is possible to ensure uniform distribution of airflow and effective impact on the surface of the filter cartridge. Under the optimal spraying distance and slot length conditions in this article， the pressure value on the side wall of the filter cartridge is relatively high and the pressure distribution is relatively uniform， which can achieve efficient dust cleaning effect. The research results of this article provide theoretical guidance for the application of slot nozzles in filter cartridge dust cleaning.

Keywords：box filter cartridge； striped nozzle； spray distance； slit length； dust cleaning performance