1. Shaft-sealing heater is the horizontal-type structure consisting of shell, piping system, water chamber and draught fan, etc., and it is equipped with two centrifugal exhaust fans. The mixture exit is connected with the power-driven draught fan, the function of which is to extract the air and steam from the shaft- sealing system of steam turbine, to heat main condensate water and prevent the steam leaking from shaft- sealing at the end to steam engine room and oil system and polluting the environment and destroying the oil quality. The whole cooler is fixed at the support by the holder at the lower part of shell. The right holder is dead point, and the left holder is used to support and guarantee that the cooler shell can swell leftwards freely. The two exhaust blowers of shaft-sealing heater are in parallel connection, with one for operation, and the other for standby. 

2. Adjustment of the mixture of steam and gas from shaft- sealing system and pressure & temperature of shaft -sealing: the steam overflowing from the station, respectively enters into steam cabinet from the inlet pipe of cooler. The mixture of steam and gas flows to the outlet along the guiding septum of the pipe system, the steam exchanges heat and condenses in flowing with pipe wall, less uncondensed steam and the cooled air are absorbed into the exhaust fan to be compressed to the pressure little higher than the atmospheric pressure, and then is exhausted into the atmosphere. 

3. The condensed water drained in shaft-sealing heater is drained into the condenser or water tank with low level via multi-level water-sealing. The condensation water of shaft-sealing heater is cooled at upper part of the water chamber and will be still drained from the upper part of the water chamber rafter four processes. The shaft-sealing heater shell is equipped with water level indicator, the cooling water inlet and the inlet of mixture of steam and gas are equipped with double metal thermometer, the inlet of mixture of steam and gas is equipped with pressure vacuum gauge.

4. After overhauling to the shaft-sealing heater, the water side, steam system, draining system of the whole cooler shall be inspected for the leakproofness of all pipelines. During operation it is required to frequently observe the variation of water level of shaft-sealing heater. If the water level is too high, it is shown that tube cracks or water draining is poor, these problems shall be eliminated immediately. 

 Preparation before the shaft-sealing heater is started:

1. Inspect whether there is leakage phenomenon in valves of all connecting pipeline. 

2. Inspect whether pressure gage and thermometer are normal. 

3. Inspect whether valves in all inlet and outlet pipeline are in normal, fully opened or fully closed status. 

4. After it is Inspected to be normal, inform the person in the center control room to start. If there is any abnormal fault, it shall not be notified to start until the inspection is finished. 

Maintenance for operation of shaft-sealing heater:

1. During operation of shaft-sealing heater, the polling(routine inspection) person at site  shall regularly inspect the valve and the pipelines for the phenomena of steam and water leakage .

2. Inspect whether the parameters of thermometer and pressure gage are within normal values or not. 

3. Pay attention to the operational condition of the exhaust fan, and check whether there is any abnormity and whether there is condensation water absorbed into the fan. 

4. The person in the center control room shall monitor the related data at any time, and shall adjust it timely if it is abnormal.

5. In case the internal pipeline of shaft-sealing pipeline is damaged and leaks water seriously and it cannot be operated normally, the whole unit shall be shut down for handling.