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12/10/03
6:53 PM
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pressure
Differential Pressure Switch
Filter Unit Filter Unit Photohelic® Gages
Series DCT500 Low Cost Timer Controller
Hopper
Alarm light triggered by Dwyer pressure switch alerts diesel engine maintenance crews to service air cleaners.
Automatic filter cleaning control system. An automatic filter cleaning control system is created with the combination of the Dwyer Photohelic® switch/gage and a DCT500 Dust Collector Timer Controller. The Photohelic® gage monitors the filters for dust build-up. When the dust build-up and pressure drop across the filters exceeds a preset limit, the Photohelic® gage activates the DCT500’s cleaning cycle. The DCT500 controls the cleaning process until the dust levels and corresponding pressure drop on the filters falls back below the preset limit. Static pressure tips and line filters are recommended to prevent migration of particulate into the Photohelic® gage.
control
The large air cleaners on diesel locomotives must be serviced promptly when the particulate build-up on the filter element exceeds a safe level. To monitor filter pressure drop in this application, the engineers specified a Dwyer 1910 differential pressure switch. It performs reliably despite severe shocks and vibration as well as elevated ambient temperatures. When the pressure drop exceeds the preset level of the switch, a red alarm light goes on in the engine cab. The alarm is latched in the “on” position, alerting maintenance crews at the destination to the need for air cleaner service.
Filter Doors Air In
Series DCT1000 with DCP Dust Collector Timer Controller
Air Out
Clean Air Outlet Filter Bags
HI
LO HI
Dirty Air Inlet
LO
Shaft
Airshock Blower Motor Controls
Dust Hopper
Cooling air for big motor passes through filter monitored by explosion-proof differential pressure switch.
Bag house cleaning system uses Dust Collector Timer Controller to initiate optimum cleaning cycle.
This large electric induction motor has rotor mounted fans that draw cooling air into each end of the motor, across the rotor, and out through the stator into an exhaust duct. To prevent accumulation of dirt and dust in the motor, incoming air is filtered. The condition of each filter is monitored by a Dwyer 1950 explosion-proof differential pressure switch which senses the differential pressure drop across the filter. An explosion-proof switch is required since this inherently safe motor design is used to drive gas compressors. If the filter pressure drop reaches a preset high limit, the switch shuts down the motor and signals an appropriate alarm.
A Dwyer DCT1000 Dust Collector Timer Controller with attachable DCP pressure sensing module monitors and controls the dust levels and corresponding pressure drop across the filter bags. The DCT1000/DCP control automatically activates the cleaning cycle when the DCT1000's pre-programmed set points have been exceeded. This on-demand control system alleviates excessive air compressor usage by preventing unnecessary cleaning which lowers energy and maintenance costs.
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