Boiler house Heat recovery systems
2
Commissioning General Following the installation and wiring of the blowdown heat recovery system and prior to refilling the cold treated water storage tank as required all isolating valves should be closed. - Ensure that the auto TDS system is isolated from the flash vessel until commissioning of the recovery system is complete. - Turn the dial of the HTS3 clockwise to read an arbitrary figure and ensure that the voltage supply to the pump is off. - Never run the pump whilst the system is dry or before the pump has been vented.
Heat exchanger Confirm that the plate pack length is correct, see the table below: Heat exchanger type Plate pack length (mm) M3-8 23 M3-10 29 M3-21 61 M3-31 90 M6-12 30 M6-15 38 M6-19 48 M6-21 53 M6-25 63 M6-33 83
Pack length
2.8 7
Note: This drawing is only a representation of a heat exchanger.
Fig. 7
Gradually open the isolating valve leading from the cold treated water storage tank to the heat exchanger inlet. Static pressure must be increased slowly to spare the gaskets any undue stress. Open the isolating valve downstream of the pump. Open the isolating valve on the remaining heat exchanger inlet. Pump / HTS3 Close the isolating valves either side of the pump i.e. on the pump outlet and on the heat exchanger inlet: - Slacken the vent plug and remove carefully. Normally the amount of water escaping will be minimal. Take care that water does not enter the terminal box. - Insert a small screwdriver into the slot in the shaft end and rotate several times to ensure that the shaft is free to move. - Replace the vent plug but do not tighten. - Open the isolating valves either side of the pump as previously described. Switch on the power supply to the system. Using a screwdriver turn the setting arrow of the HTS3 fully anti-clockwise. The setting marks outside the temperature scale provide a positive on and off position. Only when fully anti-clockwise should the pump come on. - When any remaining air has escaped and water only is present tighten the vent plug. - The pump may be noisy when first switched on due to air remaining in the chamber this should cease after a few minutes running. If noise persists then re-vent. - Position the HTS3 setting arrow to the desired temperature for switching. 65 ° C is recommended as a typical setting on this application but if this is not exactly suitable it may be adjusted later. The requirement being that the pump should run whenever there is any useful heat to recover. WARNING : Do not start the pump until the system has been filled with water and both the pump and system have been vented in accordance with the above instructions. TDS system For commissioning of auto TDS systems refer to separate literature. Open up the TDS blowdown to the flash vessel. By blowing down through the auto-TDS system check the operation of the blowdown heat recovery system and adjust the HTS3 switching temperature if required. Observe in particular the operating pressure of the flash vessel that should not exceed 0.5 bar g under normal conditions and that the heat exchanger is working correctly. The temperature of the residual blowdown flowing to drain will be below 40 ° C in most cases but this depends on the temperature of the water in the cold treated water tank.
AI-P404-07 AB Issue 7
Page 7 of 8
Boiler Blowdown Heat Recovery Systems - Installation, Operation and Maintenance
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