Condensed water desalination indirect heat exchange forced mixed secondary deaeration device

Abstract

The invention relates to a secondary deoxidizing device for performing indirect heat exchange and forced mixing on condensed water and desalted water. A pressure-bearing buffer tank is connected with first and third water inlet pipes positioned on an upper layer as well as second and fourth water inlet pipes positioned on a lower layer; mixed condensed water is introduced into the second and fourth water inlet pipes respectively after undergoing indirect heat exchange with synthetic ammonia desalted water and transformed desalted water through third and fourth heat exchangers respectively; the synthetic ammonia desalted water and transformed desalted water are introduced into the first and third water inlet pipes respectively after undergoing heat exchange through the third and fourth heat exchangers; the middle part of the top wall of the pressure-bearing buffer tank is connected with a buffer tank exhaust pipe; buffer tank output water is pumped into a high-pressure deoxidizer through a first water pump; deoxidizing box drainage water is pumped into a water replenishing pipe of a boiler through a third water pump; the top of a deoxidizing head of the high-pressure deoxidizer is connected with a deoxidizing head exhaust pipe for exhausting deoxidizing exhaust steam and non-condensable gas; a forced mixing impeller is arranged on the middle lower part of the inner cavity of the pressure-bearing buffer tank; and a bottom plate of the pressure-bearing buffer tank is connected with a blow-off pipe. The device is high in residual heat utilization ratio of condensed water, and runs reliably.

Description

technical field [0001] The invention relates to a condensed water desalinated water indirect heat exchange forced mixing secondary deaeration device, which can be used for recovery of high-temperature condensed water and heated desalinated water produced in the production line of an alkali plant. Background technique [0002] In order to prevent thermal equipment and its pipelines from corroding, and prevent non-condensable gases from mixing into steam to reduce steam quality, dissolved oxygen and other non-condensable gases dissolved in boiler make-up water must be removed, often through deaerators. According to Henry's law and Dalton's law, for various gases dissolved in water, under a certain pressure, the higher the temperature of the water, the lower the solubility; or under a certain pressure, the lower the partial pressure of the gas, the gas the lower the solubility. Thermal deoxygenation means that when the boiler replenishment water is heated to the saturation tem...

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Problems solved by technology

[0004] The above recovery methods have the following disadvantages: 1. The deaerator is atmospheric type, and the working temperature is about 104°C, but the actual temperature after mixing the condensed water and desalinated water is far higher than 104°C, so the excess part can only pass through the deaerator head A large amount of flash tank connected to the deaerator is empty, wasting a lot of waste heat and water resources

2. The temperature difference between condensed water and desalinated water is large. It is difficult to achieve a balance of heat in an instant through direct mixing and heat transfer. Therefore, thermal explosion is prone to occur in the deaeration box, which affects the safe operation of the equipment.

3. There is a contradiction between the intermittent water replenishment of the boiler and the continuity of condensed water generation: when the boiler does not replenish water or the amount of water replenished is not large, the valve opening of the calciner condensed water into the deaerator is small, the system pressure is suppressed, and the calciner grate The condensate water is not smooth; when the boiler replenishes a large amount of water, the valve opening of the calciner condensate water into the deaerator is large, the back pressure of the system is reduced, and the calciner steam is connected to the deaerator, which intensifies the discharge of waste heat

4. The volume of the deaeration box is limited, and an effective buffer cannot be formed between the boiler unit and the production unit

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