The Deaerator is vertical spray cum tray with counter flow of steam & water and with horizontal feed water storage tank.

In order to accomplish a high degree of efficient deaeration, water is sprayed through various spray nozzles arranged below the water header.

Trays are arranged in a triangular fashion to increase the resident time for fine deareation.

This arrangement will cut down the amount of phosphate additive and eliminate the need for sulphate or Hydrazine additives. This will also reduce the amount of blow down and also reduce the cost of chemical treatment.

For initial start – up / heating up of water, Sparger type arrangement is provided in the feed Water storage tank.

This arrangement will also prevent hammering effect when the deaerator is actually charged with steam.

At the deaerator storage tank outlet nozzle, a sample point is provided to measure dissolved oxygen content.

The pump suction/ outlet nozzle of the deaerator storage tank is extended up to the perforated inlet header running along the length of the storage tank as shown in the drawing. Due to this arrangement, no vortex breaker is required. Hence less pressure drop.

LP Dosing line with nozzles at definite intervals have been provided inside the deaerator storage tank.

In our design, no separate vent condenser is required. The first row of trays is designed to act as vent condenser.

The deaerator is designed to take care of all working conditions. The turn-down is 10 %.

The only place for flashing steam to go is upwards to the heater. For this to happen safely, the equalizers the balancing pipes between tank and heaters must be adequately sized.

The vents actually have a dual purpose. Not only do they provide a convenient exit for oxygen lanten steam, they also permit the steam in the spray chamber to approach as close to atmospheric pressure as possible. The reason is that the lower the partial pressure, the more readily the sprayed water gives up the dissolved gases it contains.

Problems in deaerator functioning -Troubleshooting

Reasons for poor removal of dissolved oxygen:-

Sudden water demands in the system may create a partial vacuum and if the steam control valve response is not quick enough, vacuum breakers may open allowing air to enter into the deaerator. Check Pr.gauge to see that required

control pressure is always maintained.

Poor atomization of water.

Proper sizing and opening of vent.

Check positioning of trays.

Many factors affect the operating requirements and opting for a customised deaerator may pay off in the long run.