KST – KROMSCHRÖDER SYSTEM TECHNOLOGY

DOCUTHEK

You can find all documents here.

 

docuthek.com

Process Control Systems

overview

Single burner system, pilot and main burners, 2-point-controlled, UV control

Single burner system, 2-point controlled, no air preheating, Pilot burner, pneumatic ratio control system, UV control
Flowchart No.: 1.2.1.2.2.1
Standard: EN 746-2

No. Component description Standards and Docuthek
100 Power supply unit
210 Combustion air fan
300 Safety limits
311 Air min. air pressure monitor, e.g. DG
321 Gas min. low-pressure cut-off, e.g. pressure switch for gas DG
322 Gas max. high gas pressure protection, e.g. pressure switch for gas DG
331 Emergency stop/Emergency off/Gas off, e.g. Emergency Stop button NTA
332 Overtemperature ϑ max
341 Pre-purge
350 Valve proving system, e.g. tightness control TC 1-3
350 Valve proving system, e.g. tightness control TC 410
450 Burner control unit BCU 480

The burner control unit is mounted to the burner on site and ensures simple commissioning of the burner system.

530 Temperature control

Application

Process control system (PCC) for control and 2-point temperature control of a pilot and main burner system, UV-controlled with gas and cold air supply.

Function

The supply voltage is supplied to the control system via the power supply unit (100).

Start-up of the combustion air fan (210) includes the “no flow” state check of the Air min. air pressure monitor (311).

The control block for monitoring the safety limits (300) assumes the safety-related monitoring of the safety limits Air min. air pressure monitor (311), Gas min. low-pressure cut-off (321), Gas max. high gas pressure protection device (322), Emergency stop/Emergency off/Gas off (331) and ϑ max. overtemperature monitor (332).

Once the system has started and all safety limits (300) are present, pre-purging (341) of the thermoprocessing equipment begins and the tightness control (350) checks the automatic shut-off valves. Once pre-purge (341) has been completed and the OK signal has been issued by the tightness control (350), the safety interlocks (shown in yellow) are set and the pilot burner is started by the automatic burner control unit (450). Once the automatic burner control unit (450) has received the flame signal from the pilot burner, the main burner is started in the ignition position. Once the automatic burner control unit (450) has received the flame signal from the main burner, the burner starts. The 2-point temperature controller (530) now takes over the temperature control of the heating equipment in High/Low mode.

Note

A system fault lock-out occurs if

  • at least one of the safety limits does not lie within the system operating range
  • or the tightness control (350) has detected a leak on the main gas valves or burner valves
  • or the automatic burner control unit (450) has detected a burner fault.

The system fault lock-out may only be reset manually.

The safety limits listed refer to a typical item of thermoprocessing equipment. The required safety limits may differ, depending on the system type.

The automatic burner control unit (450) and the tightness control (350) control the same automatic shut-off valves on the equipment.

In the diagram, a BCU 480 is shown for the automatic burner control unit (450). If another control unit is used, some signals must be provided by an additional control logic.

If the burner is switched ON/OFF by the temperature controller, the pre-purge and/or the tightness test must be started before each burner start.

The diagram shows the On/Off burner operating mode in heating mode. If the burner is to be operated in High/Low mode, the ϑ2 input of the automatic burner control unit must be connected to the safety interlock input of the automatic burner control unit. Then only the air valve input of the automatic burner control unit is actuated by the controller signal.

DOCUTHEK

You can find all documents here.

 

docuthek.com