Softening process for industrial raw water

Abstract

The invention discloses a softening process for industrial raw water, and the process comprises the following steps of: A. industrial raw water input; B. softening reagent injection; C. precipitation and collection of a natural crystal grain which mainly comprises CaCO3; D. cyclic reinjection of the natural crystal grain which mainly comprises CaCO3; E. crystal grain growth to become a circulating fluidized-suspended bed; F. softened water output; G. sand discharge. Compared with traditional clarifier process, the invention has the advantages of both a fluidized bed and a suspended bed, so the filtration rate is high and the volume is small; and the resultant is sand which is easy for dehydration. According to the process of the invention, the crystal nucleus is generated naturally and grows circularly by itself; no artificial processing of the crystal nucleus is necessary; and the cost for the processing and the addition of an artificial crystal nucleus is saved; the particle size and the flow velocity of the suspended crystal grain in the process of the invention are self-matched without strict requirements to the particle size of the initial crystal nucleus, and are self-adjusted, so the process condition is quite wide; no accurate matching with the filtration rate of raw water is necessary; and the process operation becomes more simple and reliable.

Description

technical field [0001] The invention relates to a process for softening industrial raw water, in particular to a process for softening industrial raw water by adopting a circulation fluidization-suspension bed softening method. Background technique [0002] In the field of water treatment, the traditional industrial raw water softening process is a clarifier process with sludge contact process. There are two main types: one is sludge return clarifier, which specifically includes hydraulic circulation clarifier, impeller circulation clarifier, and accelerated impeller circulation clarifier. Its process is characterized by making CaC0 3 The industrial raw water flow of the crystal grain (particle size about 0.01mm) product sludge is circulated at a rate of 200-400%, and the hardness factor in the raw water and the agent added are in contact with and contain CaCO during the circulation process. 3 The crystal grain product sludge is separated from the raw water for crystal nuc...

AI Technical Summary

Problems solved by technology

Its disadvantages are: 1. The process efficiency is low, and the filtration rate is 5-7 m / h, so the structure is large in size and large in investment; The amount of water is large, and the subsequent drying treatment is difficult; 3. The process occupies a lot of land and the land cost is high

Its disadvantages are: 1. It needs to consume artificial crystal nuclei continuously, increasing the operating cost; 2. The particle size of artificial crystal nuclei must be strictly matched with the rising flow rate, that is, the filtration rate. The particle size of the nucleus is 0.2-0.4mm, otherwise the artificial crystal nucleus cannot be kept in a suspended state, and the process fails; 3. During the manufacturing process of the artificial crystal nucleus, the crystal plane is polluted, the lattice is destroyed, and the new lattice is attached at the beginning of crystallization The time required for covering is long, and the softening efficiency of industrial raw water is low

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