Device and process for converting calcium process desulfurization into temperature difference crystallizing ammonia process desulfurization

Abstract

The invention belongs to the technical field of environment protection, and relates to a device and a process for temperature difference crystallizing ammonia process desulfurization, which is especially suitable for the ammonia process modification and newly-built desulfurization of the original calcium process desulfurization device. The device comprises a desulfurization tower, a densifying device, a gas-liquid heat exchanger, a circulating pump, a concentration circulating pump, a magma pump, a concentration crystallization tank and a drying system, wherein the desulfurization tower, the circulating pump, the magma pump and the drying system adopt the devices in the original calcium process desulfurization; the lower part of the densifying device is provided with a gas distributor, andthe upper part thereof is provided with spray heads which are arranged in 2-3 layers; spray heads in the desulfurization tower are arranged in 2-4 layers, a liquid supplementation pipe is connected with the spray heads at the lowest layer in the desulfurization tower; the concentration crystallization tank is a tank with a conical bottom part; and the upper part of the concentration crystallization tank is provided with a pipeline to be connected with the bottom of the densifying device, the middle of the concentration crystallization tank is provided with a pipeline to be connected with theconcentration circulating pump, and the bottom is provided with a pipeline to be connected with the magma pump. The invention can farthest utilize the original devices on the premise of guaranteeing the normal desulfurization efficiency, thereby saving the investment, reducing the energy consumption and eliminating the secondary pollution.

Description

technical field [0001] The invention belongs to the technical field of environmental protection, and relates to a temperature-difference crystallization ammonia method desulfurization device and a process, and is especially suitable for the modification or new desulfurization of the original calcium method desulfurization device of a thermal power plant. Background technique [0002] At present, the known calcium method (ie, limestone method) desulfurization process produces waste liquid during operation, and at the same time, waste residue calcium sulfate is generated, causing secondary pollution. However, ammonia desulfurization can eliminate the discharge of waste liquid and waste residue, and the ammonium sulfate produced can be used. Therefore, many calcium desulfurization methods are converted to ammonia desulfurization with high efficiency and low energy consumption. The most expensive desulfurization tower in calcium desulfurization is the desulfurization tower. Due...

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Problems solved by technology

[0003] In order to overcome the deficiencies of the existing technology, solve the secondary pollution caused by calcium desulfurization, and the steel structure strength of the desulfurization tower in the desulfurization tower is insufficient, the layer height is insufficient, the anti-corrosion layer is difficult to repair, and the anti-corrosion material is not resistant to high heat and temperature. Rapid changes, etc., the usual ammonia desulfurization process has the problem that ammonium sulfate in the absorption liquid is easy to crystallize in the nozzles and pipelines and other parts to cause blockage. The present invention provides a device and process for converting calcium desulfurization to temperature difference crystallization ammonia desulfurization The original desulfurization tower, circulating pump, crystal slurry pump and drying system are used without changing the internal structure of the desulfurization tower, so as to achieve the purpose of purifying and discharging flue gas without causing secondary pollution

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