Equipment and process for preheating raw water by using heat of reverse osmosis system

Abstract

The invention discloses equipment and a process for preheating raw water by using heat of a reverse osmosis system. A concentrated solution of the reverse osmosis system enters a concentrated solution heat recovery plate heat exchanger through a concentrated solution pipeline to carry out temperature rise and heat exchange on the raw water in a first branch pipe; permeate liquid of the reverse osmosis system passes through a permeate liquid pipeline and is heated by a heating device, and then enters a permeate liquid heat recovery plate exchanger to carry out temperature rise and heat exchange on raw water in a second branch pipe; and the raw water subjected to heat exchange in the first branch pipe and the raw water subjected to heat exchange in the second branch pipe are converged and then enter the reverse osmosis system. The equipment and the process have the advantages that: (1) energy is saved: heat of concentrated liquid and permeate liquid of the system is recycled, and the heat is recycled to the maximum extent; 2, low corrosion is achieved: the permeate liquid is used for heating, so that the corrosion problem of an electric heating wire is reduced; and (3) the plate heat exchangers are utilized, heat exchange is efficient, the cost is low, maintenance is convenient, and the process is simple.

Description

technical field [0001] The invention relates to the technical field of sewage treatment, in particular to a device and a process for preheating raw water by utilizing the heat of a reverse osmosis system. Background technique [0002] The reverse osmosis device is to pass the raw water through a fine filter, a granular activated carbon filter, etc., and then pressurize it through a booster pump, and use a reverse osmosis membrane (RO membrane) with a pore size of 1 / 10000 μm to remove pollutants, heavy metals, and pollutants in the raw water. Bacteria, viruses, organic matter, charged ions, colloidal particles, etc. are all isolated, and clean to pure water is produced. Reverse osmosis unit applying membrane separation technology is the best equipment in high-purity water preparation, brackish water desalination and landfill leachate, pharmaceutical wastewater and other wastewater treatment processes. Widely used in electronics, medicine, food, textile, chemical industry, po...

AI Technical Summary

Problems solved by technology

Based on the above reasons, the reverse osmosis system is in most of the northern regions of our country and other low-temperature regions. Because of the cold weather and low water temperature, the system cannot operate. Frequent, high energy consumption, high operating costs and a series of problems

[0005] The traditional solution is to directly heat the raw water to the temperature required by the reverse osmosis system. This method is prone to problems: 1. Because the raw water and wastewater are generally highly corrosive, direct raw water heating will cause the electric heating wire to be easily corroded, even if the corrosion-resistant The 316L material electric heating wire will also cause corrosion due to ions in the wastewater (chloride ion Cl-, fluoride ion F-, etc.); 2. High energy consumption, high-pressure pumps, fans, metering pumps, etc. running in the reverse osmosis system The energy will be transferred to the concentrate and clear water (permeate) from the system. The temperature of the concentrate and permeate will be higher than the temperature of the system inlet liquid (operating experience is generally 4-6°C), and the heat cannot be recovered. In-line waste, resulting in high energy consumption

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