Condensed water desalination mixed recovery secondary oxygen removal device

Abstract

The invention relates to a condensate water and demineralized water mixed recovery two-stage deoxygenization apparatus. According to the invention, a first water inlet pipe and a third water inlet pipe positioned on an upper level and a second water inlet pipe and a fourth water inlet pipe positioned on a lower level are connected on the circumference of a pressure-bearing buffering tank. Synthetic ammonia cooling demineralized water and transformation cooling demineralized water are respectively connected into the first water inlet pipe and the third water inlet pipe. Calcining furnace condensate water and fluidized bed condensate water are respectively connected into the second water inlet pipe and the fourth water inlet pipe. A buffering tank exhaust pipe is connected to the middle part of the top wall of the pressure-bearing buffering tank. A check valve and a first control valve are sequentially arranged from bottom to top on the buffering tank exhaust pipe. A lower end of a water outlet pipe of the buffering tank penetrates through the bottom plate of the pressure-bearing buffering tank and is connected to a first water pump. An outlet of the first water pump is connected to a deoxygenization head water inlet pipe of a high-pressure deoxygenization device. A deoxygenization tank drain pipe of the deoxygenization device is connected into a boiler water replenishing pipe through a third water pump. A sewage outlet is arranged on the bottom plate of the pressure-bearing buffering tank. The sewage outlet is connected with a sewage discharge pipe. A second control valve is arranged on the sewage discharge pipe. The apparatus provided by the invention has the advantages of high condensate water residual heat utilization rate and reliable operation.

Description

technical field [0001] The invention relates to a two-stage oxygen removal device for mixed recovery of condensed water and desalinated water, which can be used for recovering 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 temperature...

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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 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 opening of the valve for the condensed water entering the deaerator of the calciner is small, the pressure of the system 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 it cannot form an effective buffer between the boiler unit and the production unit

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