Cement, Energy and Environment

I ..t., / Figure 4. Bag filter design. Selectors for manual control of the modules were included for maintenance purposes (one module at a time with automatic exclusion of the related cleaning electrovalves). Using the automatic operating mode, start and stop of the bag cleaning cycles are set to achieve the pre-set pressure drop values through the bags. These pressure drop values, as well as the alarm values for high pressure drop, are adjustable. The control box has various LED Indicators for signalling, a display for visualization of Instant pressure drop values, an alarm switch for high pressure drop through the bag (both manual and automatic operations), a pressure drop output signal (4 -20 rnA), an operating hours counter and the possibility to reset a certain number of bag cleaning cycles after fan stop. Stack emissions: project results Before revamping: Dust emission >200 mg/Nm 3 After revamping: Dust emission <5mg/Nm 3 . Case B The customer is one of the biggest players in the cement industry with five rotary kilns. The requirement of the client was the revamping of the dedusting system for the clinker rotary kiln . The existing system had various problems. Each production line is connected to an old generation ESP filter and all lines experience filter casing corrosion and high emission levels above legal requirements. Due to the high humidity of the fumes, the existing heat exchanger had clogging problems and the client requirement was to avoid any cooling devices in the new plant. Hascon therefore had to take special care to keep the fume dew point under control , which could be the cause of earlier bag clogging and casing corrosion. The dust inlet concentration at the ESP before Hascon's intervention was 54g/m 3 . The dust concentration at the ESP outlet was 150 mg/m 3 . The client required a new bag filter plant with dust concentration at the outlet of less than 1 Omg/m 3 . The plant also has problems due to the extreme climate conditions of the location, where temperatures can reach -40' . Table-4 General technical data Number of filters Nominal flow rate Effective flow rate Effective flow rate after fresh air damper system Content of the wasted air Density of dust Inlet dust concentration 1 80 000 Nm% (for calculate) 159121 m 3 /h at 270 ·c 183 000 m 3 /h at 220'C Clinker dust 1300 kg/m 3 54 g/m 3 Table-s Technical features of bag filter Operating temperature Rotation speed Static pressure at 220'C Absorbed power at 220'C lnstalled power Sound preaaure level at 1.5 m dlatance, free fteld, with l*tloutltt cNcted 1490 rpm 350mmw.g. 260kW 315kW S85 c:IB(A) 35