System and method for increasing low-temperature heat energy recycling and utilizing rate in hot process-based phosphoric acid production

Abstract

The invention discloses a system and a method for increasing the low-temperature heat energy recycling and utilizing rate in hot process-based phosphoric acid production, and relates to the field of phosphoric acid production. The system cooperates with a hydration tower; the hydration tower can produce high-concentration high-temperature phosphoric acid, and comprises a heat exchange mechanism and a dilutor which are connected in sequence; the heat exchange mechanism is used for exchanging heat in the high-concentration high-temperature phosphoric acid through a heat exchange medium; recycled high-level heat energy (such as steam) is applied to production; meanwhile, the high-concentration high-temperature phosphoric acid is converted into high-concentration low-temperature phosphoric acid which is then introduced into the dilutor; the dilutor is used for diluting the high-concentration low-temperature phosphoric acid into low-concentration phosphoric acid which is then introduced into the hydration tower. According to the system, the heat energy utilization rate of a phosphoric acid hydration process section at relatively low temperature in the hot-process-based phosphoric acid production can be increased, and the economical value is improved.

Description

technical field [0001] The invention relates to the field of phosphoric acid production, in particular to a system and method for improving the recovery and utilization rate of low-temperature heat energy in thermal phosphoric acid production. Background technique [0002] Phosphoric acid prepared by thermal method is obtained by burning and oxidizing yellow phosphorus to obtain phosphorus pentoxide, and then passing phosphorus pentoxide into a hydration tower for hydration and absorption. Consumption of production leads to higher cost of phosphoric acid prepared by thermal method. [0003] Since the combustion of yellow phosphorus itself is an exothermic reaction, and the temperature of the obtained phosphorus pentoxide is relatively high, for this reason, relevant equipment has been developed in this field to absorb the heat released by the combustion of yellow phosphorus and the heat of high-temperature phosphorus pentoxide Utilize to reduce the heat energy used in therm...

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Problems solved by technology

[0004] However, in the phosphoric acid hydration (phosphoric acid pentoxide reacts with water to form phosphoric acid) process section, the traditional hydration process controls the outlet acid temperature of the hydration tower to not be higher than 80°C by continuously cooling the water supply to the wall of the hydration tower, which causes a large number of High-temperature heat energy is reduced to low-temperature heat, so that the utilization rate of heat energy in the hydration process section is relatively low, and it can only be used as simple hot water, which is difficult to generate high economic value. waste

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