# Effect of Venturi Structures on the Cleaning Performance of a Pulse Jet Baghouse
## 2 Materials and Methods
### Experimental Apparatus  
Figure 3 shows the experimental bench approach for determining the performance of the pulse jet cleaning. This consists of a compressed air supply system, a pulse jet system, a filter bag and bag cage installed with the venturi tube (Figure 2), and a data acquisition system. The compressed air was supplied by an air compressor (Model AX2025; PUMA Inc., Memphis, TN, USA); the air tank was used to store the compressed air and maintain a constant the pulsing airflow pressure, which was monitored by a pressure gauge (Model Y-60A; Shanghai Automation Instrument Co., Ltd., Shanghai, China). The pulse controller (Model DMK-3 CS; SBFEC. Inc., Shanghai, China) was used to control the opening and closing time of the electromagnetic pulse valve (Model DMF-Y-102S; SBFEC. Inc., Shanghai, China), thus adjusting the blowing time of the compressed pulsing air (the pulsing air injection time). The distance between the nozzle and the bag mouth was 170 mm, and the diameter of the nozzle hole was 18 mm. The tested filter bag was made of polyester with a thickness of 1.8 mm, a diameter of 130 mm and a length of 8000 mm. The bag cage diameter was 125 mm, and the length 7950 mm. The position distribution of the measuring points on the filter bag is shown in Figure 3b. The measuring points located 1000, 4000, and 8000 mm from the mouth of the bag were named \"top\", \"middle\", and \"bottom\", respectively. The pressure transmitters (Model 316B2 ER; Shanghai Automation Instrument Co., Ltd., Shanghai, China, measurement accuracy: 0.1 Pa) were installed at the filter bag measuring points for collecting the cleaning pressure data. An oscilloscope (Model DPO 2014; TEKTRONIX, INC., Beaverton, OR, USA, sampling accuracy: 1 ns) and computer were used to record the duration of the cleaning pressure. In this paper, the effect of the venturi structure on the cleaning performance of the filter bag was studied by collecting the peak pressure and the peak pressure arrival time at different points on the test filter bags. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Test Device**} & \multirow{2}{*}{**Test No.**} & \multirow{2}{*}{\begin{tabular}{c} **The Pulsing Air** \\ **Pressure.** \\ **\(P_{pu}\)** \\ **(MPa)** \\ \end{tabular} } & \multicolumn{2}{c}{\begin{tabular}{c} **The Pulsing Air** \\ **Injection Time.** \\ **(MPa)** \\ \end{tabular} } & \multicolumn{2}{c}{\begin{tabular}{c} **The The Type of** \\ **Venturi.** \\ **(ms)** \\ \end{tabular} } & \multicolumn{2}{c}{\begin{tabular}{c} **The Throat** \\ **Diameter of** \\ **Venturi.** \\ **(mm)** \\ \end{tabular} } & \multicolumn{2}{c}{\begin{tabular}{c} **The Length of** \\ **Venturi.** \\ **(mm)** \\ \end{tabular} } \\ \hline \multirow{4}{*}{\
\begin{tabular}{c} Experimental bench for the \\ performance of pulse jet cleaning \\ (see Figure 3) \\ \end{tabular} } & 1 & 0.3, 0.4, 0.5 & 100 & Typical & 40 & 200 \\  & 2 & 0.4 & 100, 150, 200 & Typical & 40 & 200 \\  & 3 & 0.4 & 100 & Typical & 40, 50, 60 & 200 \\  & 4 & 0.4 & 100 & Typical & 60 & 160, 180, 200 \\  & 5 & 0.4 & 100 & New & 60 & 160 \\ \hline \multirow{4}{*}{
\begin{tabular}{c} Semi-industrial bashouse \\ experimental device (see Figure 4) \\ \end{tabular} } & 6 & 0.4 & 100 & Typical & 60 & 160 \\  & 7 & 0.4 & 100 & New & 60 & 160 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Experimental design and arrangement. Based on the results related to the influence of the venturi tube structure on the filter bag cleaning performance, this research group determined the effects of two types of venturi on the cleaning performance and dust emission concentration of the baghouse in a semi-industrial scenario. Figure 4 shows a semi-industrial baghouse experimental device, which can simulate the working characteristics of a baghouse under real filtering conditions. The semi-industrial baghouse was designed with a dust feeder, a pulse jet cleaning system, a filtering unit, a power system, and a test system.