Domestic sewage treatment secondary utilization system suitable for pelletizing industry

Abstract

The invention provides a secondary utilization system after domestic sewage treatment suitable for the pellet industry, which comprises a domestic sewage treatment system for carrying out water quantity regulation, water quality regulation, biochemical treatment, microbiological treatment, MBR (Membrane Bioreactor) treatment, ozone treatment and filtration treatment on sewage step by step so as to obtain clear water; the sewage recovery system is used for conveying clear water to the cooling water circulation system; and the circulating cooling water system is used for cooling the clear water step by step and cooling the equipment needing to be cooled by cooling water. The domestic sewage treatment system comprises a sewage regulating tank, an anoxic tank, an oxygen consumption tank, an MBR tank, a two-stage activated carbon filter, a two-stage precision filter, an ozone generator, an ozone tower and a clean water tank which are sequentially connected in the sewage flowing direction; the sewage treatment and recycling system provided by the invention successfully realizes zero discharge of domestic sewage.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and in particular to a system for secondary utilization of treated domestic sewage suitable for the pelletizing industry. Background Art

[0002] Pelletizing plants, steel mills, coal refineries and other factories will build supporting living areas around them for workers to live in. Domestic sewage generated during life comes from wastewater discharged from living facilities such as toilets, kitchens, and shower rooms. Because it contains sediment, grease, soap, food scraps, debris, bacteria and other substances, it is reflected in the water quality indicators, namely high biochemical oxygen demand (BOD5), chemical oxygen demand (COD), suspended solids (SS), high nitrogen and phosphorus content, and eutrophication.

[0003] At present, most domestic sewage is directly discharged after being treated by sewage pumping stations, and cannot be recycled, which not only has a certain impact on the environment, but also causes a waste of resources. At the same time, the current governance of environmental pollution is accelerating, and the requirements for sewage discharge are becoming increasingly stringent. Therefore, the problem of domestic sewage treatment is becoming increasingly prominent, the price of industrial water is constantly rising, and the waste is relatively serious, and the production cost is high. In addition, many mechanical equipment in the pelletizing plant, steel mill, coal refinery and other plant areas require a large amount of cooling water for cooling, which consumes a lot of resources and expenses. Summary of the invention

[0004] According to the above technical problem that the existing discharged sewage is not recycled, a system for secondary utilization of domestic sewage after treatment suitable for the pelletizing industry is provided. The present invention mainly utilizes the domestic sewage treatment system, sewage recycling system and circulating cooling water system to purify the sewage, thereby achieving the purpose of sewage reuse.

[0005] The technical means adopted by the present invention are as follows:

[0006] A system for secondary utilization of domestic sewage after treatment suitable for the pelletizing industry, comprising:

[0007] Domestic sewage treatment system used to carry out water quantity regulation, water quality regulation, biochemical treatment, microbial treatment, MBR treatment, ozone treatment, and filtration treatment on sewage step by step to obtain clean water;

[0008] A sewage recovery system used to transport clean water to the cooling water circulation system;

[0009] A circulating cooling water system is used to cool clean water step by step and allow the cooling water to cool the equipment that needs cooling.

[0010] Furthermore, the domestic sewage treatment system includes a sewage regulating tank, an anoxic tank, an oxygen consumption tank, an MBR tank, a second-stage activated carbon filter, a second-stage precision filter, an ozone generator, an ozone tower and a clear water tank which are sequentially connected along the sewage flow direction;

[0011] The sewage recovery system includes a centrifugal pump, a water pipeline, and a PLC controller. The clean water tank is connected to one end of the water pipeline through the centrifugal pump, and the other end of the water pipeline is connected to the hot water tank of the circulating cooling water system. The PLC controller is electrically connected to the centrifugal pump;

[0012] The circulating cooling water system comprises a hot water tank, an upper tower pump, a cooling tower, a cold water tank, a circulating pump and equipment to be cooled which are connected in sequence.

[0013] Furthermore, a grille is arranged in front of the inlet of the sewage regulating tank, a perforated aeration pipe is laid at the bottom of the sewage regulating tank, and the outlet of the sewage regulating tank is connected to the anoxic tank through a lifting pump.

[0014] Furthermore, nitrifying bacteria are arranged in the aerobic pool.

[0015] Furthermore, fillers are arranged in the aerobic pool, and the nitrifying bacteria are attached to the fillers.

[0016] Furthermore, an upper water level sensor and a lower water level sensor are arranged on the inner wall of the clear water tank, and the upper water level sensor is wirelessly connected to the PLC controller. When the water level of the clear water tank reaches the height of the upper water level sensor, the water level sensor sends a first liquid level signal to the PLC controller, and the PLC controller receives the first liquid level signal and sends a start signal to the centrifugal pump. When the water level of the clear water tank reaches the height of the lower water level sensor, the lower water level sensor sends a second liquid level signal to the PLC controller, and the PLC controller receives the second liquid level signal and sends a stop signal to the centrifugal pump.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] The present invention solves the zero-discharge problem of domestic sewage treatment and solves the environmental protection problem by setting up a domestic sewage treatment system, a sewage recovery system and a cooling water circulation system. At the same time, about 240 tons of domestic sewage will be treated every day, and the clarified water that meets the treatment standards will pass through the drainage ditch outside the drainage pipe, and about 87,600 tons of water will be wasted each year. The unit price of new water is 3.5 yuan / ton. The value of wasted water throughout the year reaches 306,600 yuan. Now this part of water has been successfully used reasonably in the cooling circulating water system, which can save 300,000 yuan in costs each year. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 This is a structural diagram of the domestic sewage treatment system of the present invention.

[0021] Figure 2 This is a structural diagram of the sewage recovery system of the present invention.

[0022] Figure 3 This is a structural diagram of the cooling water circulation system of the present invention. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0026] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, the numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0027] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0028] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0029] like Figure 1-3 As shown, the present invention provides a system for secondary utilization of domestic sewage after treatment applicable to the pelletizing industry, comprising:

[0030] Domestic sewage treatment system used to carry out water quantity regulation, water quality regulation, biochemical treatment, microbial treatment, MBR treatment, ozone treatment, and filtration treatment on sewage step by step to obtain clean water;

[0031] A sewage recovery system used to transport clean water to the cooling water circulation system;

[0032] A circulating cooling water system is used to cool clean water step by step and allow the cooling water to cool the equipment that needs to be cooled.

[0033] The domestic sewage treatment system comprises a sewage regulating tank, an anoxic tank, an oxygen consumption tank, an MBR tank, a second-stage activated carbon filter, a second-stage precision filter, an ozone generator, an ozone tower and a clear water tank which are sequentially connected along the sewage flow direction;

[0034] The collected domestic sewage passes through a screen to remove larger suspended matter, floating matter and ribbons in the water, and flows into the regulating tank by gravity. The purpose of setting up the regulating tank is to regulate the amount and quality of sewage. In order to prevent the suspended matter from settling in the regulating tank, there is a perforated aeration pipe at the bottom of the regulating tank, and intermittent aeration is used. The effluent of the regulating tank enters the anoxic tank and the aerobic tank for biochemical treatment by the lifting pump. After the biochemical reaction in the anoxic tank, there is still a certain amount of organic matter and high nitrogen and ammonia in the sewage. In order to further oxidize and decompose the organic matter, and at the same time, when the carbonization is almost complete, the nitrification can proceed smoothly, and then enter the aerobic tank for treatment. It depends on autotrophic bacteria (nitrifying bacteria). They use the inorganic carbon source produced by the decomposition of organic matter or carbon dioxide in the air as a nutrient source to convert ammonia nitrogen in the sewage into NO2--N and NO3--N. Fillers are installed in the anoxic tank and the aerobic tank biochemical tank, and the entire biochemical treatment process depends on a variety of microorganisms attached to the fillers. Finally, entering the MBR pool can efficiently remove organic matter and nutrients such as nitrogen and phosphorus in the sewage to obtain high-quality treated water. The treated sewage then passes through a series of filtering devices and ozone sterilization and finally flows into the clean water tank.

[0035] The chemical means and biological means used for sewage treatment in the present invention are all conventional technical means.

[0036] The sewage recovery system includes a centrifugal pump, a water pipeline, and a PLC controller. The clean water tank is connected to one end of the water pipeline through the centrifugal pump, and the other end of the water pipeline is connected to the hot water tank of the circulating cooling water system. The PLC controller is electrically connected to the centrifugal pump;

[0037] An upper water level sensor and a lower water level sensor are arranged on the inner wall of the clean water tank. The upper water level sensor is wirelessly connected to the PLC controller. When the water level of the clean water tank reaches the height of the upper water level sensor, the water level sensor sends a first liquid level signal to the PLC controller. The PLC controller receives the first liquid level signal and sends a start signal to the centrifugal pump. When the water level of the clean water tank reaches the height of the lower water level sensor, the lower water level sensor sends a second liquid level signal to the PLC controller. The PLC controller receives the second liquid level signal and sends a stop signal to the centrifugal pump. The upper water level sensor is arranged at 5 meters, and the lower water level sensor is arranged at 2 meters.

[0038] The circulating cooling water system comprises a hot water tank, an upper tower pump, a cooling tower, a cold water tank, a circulating pump and equipment to be cooled which are connected in sequence.

[0039] The hot water from the cooling cycle first enters the hot water pool, and then the hot water is pumped into the cooling tower through the upper tower pump for cooling. The cooled water enters the cold water pool, and the cold water is transported to the thermal equipment that needs to be cooled through the circulating pump. Since the water in the circulating cooling water system will be cooled and evaporated, it is normal to need to add new water. This patent uses the clean water treated by the sewage pump station as the new water to be added, which not only saves water resources, but is also more environmentally friendly and successfully achieves zero discharge of domestic sewage.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A system for secondary utilization of domestic sewage after treatment suitable for the pelletizing industry, characterized in that: include: Domestic sewage treatment system used to carry out water quantity regulation, water quality regulation, biochemical treatment, microbial treatment, MBR treatment, ozone treatment, and filtration treatment on sewage step by step to obtain clean water; A sewage recovery system used to transport clean water to the cooling water circulation system; A circulating cooling water system is used to cool clean water step by step and allow the cooling water to cool the equipment that needs cooling.

2. The system for secondary utilization of treated domestic sewage suitable for the pelletizing industry according to claim 1, characterized in that: The domestic sewage treatment system comprises a sewage regulating tank, an anoxic tank, an oxygen consumption tank, an MBR tank, a second-stage activated carbon filter, a second-stage precision filter, an ozone generator, an ozone tower and a clear water tank which are sequentially connected along the sewage flow direction; The sewage recovery system includes a centrifugal pump, a water pipeline, and a PLC controller. The clean water tank is connected to one end of the water pipeline through the centrifugal pump, and the other end of the water pipeline is connected to the hot water tank of the circulating cooling water system. The PLC controller is electrically connected to the centrifugal pump; The circulating cooling water system comprises a hot water tank, an upper tower pump, a cooling tower, a cold water tank, a circulating pump and equipment to be cooled which are connected in sequence.

3. The system for secondary utilization of treated domestic sewage suitable for the pelletizing industry according to claim 2, characterized in that: A grille is arranged in front of the inlet of the sewage regulating tank, a perforated aeration pipe is laid at the bottom of the sewage regulating tank, and the outlet of the sewage regulating tank is connected to the anoxic tank through a lifting pump.

4. The system for secondary utilization of domestic sewage after treatment suitable for the pelletizing industry according to claim 2 is characterized in that: Nitrifying bacteria are arranged in the aerobic pool.

5. The system for secondary utilization of treated domestic sewage suitable for pelletizing industry according to claim 3, characterized in that: The aerobic pool is provided with fillers, and the nitrifying bacteria are attached to the fillers.

6. The system for secondary utilization of treated domestic sewage suitable for the pelletizing industry according to claim 2, characterized in that: An upper water level sensor and a lower water level sensor are arranged on the inner wall of the clear water tank. The upper water level sensor is wirelessly connected to the PLC controller. When the water level of the clear water tank reaches the height of the upper water level sensor, the water level sensor sends a first liquid level signal to the PLC controller, and the PLC controller receives the first liquid level signal and sends a start signal to the centrifugal pump. When the water level of the clear water tank reaches the height of the lower water level sensor, the lower water level sensor sends a second liquid level signal to the PLC controller, and the PLC controller receives the second liquid level signal and sends a stop signal to the centrifugal pump.

Images