CN104652573A - Vacuum drainage system technology and device used for collecting municipal wastewater - Google Patents

Abstract

The invention proposes a vacuum drainage system technology and device for municipal sewage collection. An emptying pipe is installed at the end of the vacuum pipe network. The emptying pipe is installed on the vacuum pipe side of the vacuum valve connected to the water collection tank, and is controlled The opening and closing valve is connected to the atmosphere. When the vacuum valve is opened, when the vacuum at the end of the pipe network is too low, a small amount of air is added through the exhaust pipe, thereby reducing the requirement for the vacuum degree at the end of the vacuum pipe network. Vacuum drainage can be realized when the relative vacuum degree is less than 0. When the suction-type vacuum pump is used as the vacuum source, there is no need to install a large-scale vacuum energy storage device in the vacuum pump station, and the vacuum pump station does not need to be installed in a sunken manner. When the air-water mixed vacuum pump is used as the vacuum source and drainage device, it can avoid the overheating of the vacuum pump due to long-term evacuation.

Description

A vacuum drainage system technology and device for municipal sewage collection

technical field

The invention belongs to the technical field of municipal drainage, and in particular relates to a system technology for collecting and discharging sewage from residential quarters by using vacuum drainage technology.

Background technique

Residential sewage collection is an important part of municipal drainage and sewage treatment. Its purpose is to collect the sewage discharged by multiple drainage units in the community and transport it to the main pipeline for discharge or discharge it after treatment through sewage treatment facilities. The conventional community sewage collection technology is gravity drainage technology, that is to use the weight of water to make the sewage discharged from each drainage unit enter the water collection branch pipe and converge to the water collection main pipe to achieve the purpose of collecting community sewage. There are blind spots in the application of gravity drainage technology, and it is difficult to fully collect municipal sewage. One situation is that some drainage units have low terrain, and the sewage cannot flow into the main pipe by itself; the other situation is that the diameter of the gravity drainage pipe is large and the depth of the pipe is large, and some residential areas are not equipped for laying due to geology, ground buildings, roads and other factors. Construction conditions for gravity drainage pipes. The vacuum drainage technology can realize the sewage collection in the gravity drainage blind area mentioned above. The vacuum drainage technology system usually consists of a water collection tank, a vacuum valve, a vacuum pipeline, a vacuum tank, a vacuum pumping station and a control system. The drainage principle is to use a vacuum source such as a vacuum pump to form a negative pressure in the vacuum pipe system. When the vacuum valve connecting the vacuum pipe and the water collection tank is opened, the sewage in the water collection tank enters the vacuum pipe and flows to the vacuum pipe driven by vacuum suction. The vacuum sewage collection terminal is finally discharged from the vacuum drainage system through sewage pumps, etc. The resistance of water transport in the vacuum pipeline includes hydraulic self-weight and pipeline resistance along the way. In order to ensure that the sewage entering the water collection tank can be discharged through the vacuum pipe system smoothly, a certain residual negative pressure must always be maintained at the end of the vacuum pipe connecting the water collection tank, usually below -10kPa.

According to the source of vacuum generation and its drainage method, vacuum drainage can be divided into two forms: vacuum holding type and online vacuum type. In the former, a vacuum tank must be installed between the vacuum pump and the vacuum pipeline to store vacuum energy, and the vacuum pump is used to suck the air in the vacuum tank to form a negative pressure in the vacuum tank, and then drive the sewage in the vacuum pipeline connected to the vacuum tank to collect into the vacuum tank. Then the sewage in the vacuum tank is discharged through the sewage pump. During this process, the sewage does not enter the vacuum pump; the latter uses a special vacuum pump to directly suck the air-water mixture in the vacuum pipeline and discharge it out of the vacuum system. Medium sewage needs to pass through the vacuum pump. Both have pros and cons. The former type of vacuum pump is easy to choose, and there are many mature products available in the market, but the system is complicated. The latter system is simple, but a special vacuum pump must be used. The two adopt different strategies to ensure the peripheral residual negative pressure. The vacuum holding type mainly increases the volume of the vacuum energy storage tank, and usually requires a sunken installation for the vacuum tank, so the pump station occupies a large area and is difficult to construct. The online vacuum type mainly relies on prolonging the suction time, but because the online vacuum pump relies on the sewage passing through it to cool the pump body, long-term suction of air will cause the pump body to overheat.

Contents of the invention

The main purpose of the present invention is to absorb the advantages of the two existing vacuum drainage methods and overcome the disadvantages of both.

Water is transported in the form of discontinuous columns in the vacuum pipe, and a section of air column is kept between two sections of water columns. The power for each section of water column to move forward must be provided by the pressure difference between its front end face and rear end face. When the pressure difference is not enough to overcome the resistance and the self-weight of the water column, the vacuum drainage cannot be carried out. This situation is generally easy to occur at the end of the pipe network.

The key of the present invention is to install an emptying pipe connected to the air at the end of the vacuum pipe, and to control the opening and closing of the emptying pipe, and to increase the pressure difference between the front end surface and the rear end surface of the water column by adding a certain amount of air, so that the water column at the end can Good luck.

The content of the present invention includes: an emptying pipe and its air supply method, an integrated pumping station and its method.

The emptying pipe 1 is set at the outlet side 5 of the vacuum valve 4 connecting the vacuum water collection tank 2 and the vacuum pipeline 3 at the end of the pipe network. The emptying pipe 1 is connected to the atmosphere 7 through a one-way controllable open-close valve 6, and the valve 6 is opened. , air can enter the vacuum pipe, close the valve 6, the air can not enter the vacuum pipe 3, but no matter whether the valve 6 is opened or closed, the gas or water in the vacuum pipe 3 cannot overflow from the emptying pipe 1. After vacuum valve 4 is opened, if the relative vacuum of its water outlet side 5 is too low, open valve 6, close valve 6 after a short time, as preferably, valve 6 is set to 5-15 seconds each opening time. A strategy for controlling the opening of the valve 6 is to detect the vacuum degree of the water side 5 during the opening period of the vacuum valve 4, and open the valve 6 when the relative vacuum degree of the water outlet side 5 of the vacuum valve 6 is greater than the set value. The valve 6 is opened when the vacuum degree of 5 is greater than -2kPa. Another strategy for controlling the opening of the valve 6 is to open and close the valve 6 every time a set time is delayed after the vacuum valve 4 is opened, preferably the set time is 5-15 minutes.

There are two ways to integrate pumping stations and methods. The integrated pumping station 81 of method 1 selects an aspirating vacuum pump as a vacuum generating source, and is composed of a vacuum pump 9 , an air-water tank 10 , and a drainage pump 11 . The air-water tank 10 is connected to the vacuum pipeline 3 through the connection port 12 arranged at the middle part of the tank body, connected to the vacuum pump 9 through the connection port 13 provided at the top of the tank body, and connected to the drain pump 11 through the connection port 14 arranged at the bottom of the tank body. Water outlet connection. The connection port 12 is above the liquid surface 15 in the tank, preferably the minimum vertical distance between the connection port 12 and the liquid surface 15 is 10-20 cm. The connection port 13 and the liquid surface 15 must maintain a certain height difference to prevent water from entering the vacuum pump, preferably the height difference is not less than 80cm-120cm. A certain height difference between the connection port 14 and the liquid surface 15 should be maintained to meet the working requirements of the drainage pump, preferably the height difference is 10-15cm. The air-water tank 10 must meet the relevant standards and specifications for pressure vessels. Generally, the middle section is cylindrical, and the upper and lower bottoms are arc-shaped. Next, its volume and main geometric dimensions are determined according to the amount of water to be temporarily stored in it. Preferably, a screen is arranged along the cross-section of the gas-water tank 10 between the connection port 12 and the connection port 14 in the gas-water tank 10 to intercept foreign matter entering the gas-water tank 10 through the vacuum pipeline 3 . Detect the relative vacuum above the liquid level 15 of the air-water tank 10 to determine the opening and closing of the vacuum pump, preferably the control range of the relative vacuum is -45kPa to -65kPa. Detect the position of the liquid level 15 in the gas-water tank 10 to control the opening and closing of the drain pump 11, start the drain pump 11 when the liquid level 15 reaches the set value, and pass the water in the gas-water tank 10 through the outlet of the drain pump 11 The nozzle is discharged. The integrated pumping station 82 of method 2 selects the air-water mixed pumping type vacuum pump as the source of vacuum generation, and is composed of a vacuum pump 16 and an air-water tank 17. The connection port 19 at the bottom of the tank is connected to the inlet of the vacuum pump 16 . Detect the vacuum degree inside the air-water tank 17 to control the opening and closing of the vacuum pump, preferably the vacuum degree control range is -45kPa to -65kPa. When the vacuum pump 16 was turned on, the water or gas in the air-water tank 17 was discharged through the outlet of the vacuum pump 16 . The air-water tank 17 must meet the standards and norms of general pressure vessels, preferably a screen is set inside it to intercept the sundries that enter the air-water tank 17 through the vacuum tube and enter the vacuum pump 16. Since the vacuum pump 16 can pump both air and water, there is no special requirement on the volume of the air-water tank 17 . Since the vacuum requirement on the end of the pipe network is reduced, if a vacuum pumping station 81 is used, the pumping station can be installed on the ground. Applying the technical method of the present invention, such as adopting the vacuum pumping station 82, can prevent the pumping station 82 from heating due to long-time empty pumping.

In order to realize the operation control of the entire vacuum drainage system including the emptying pipe 1, the vacuum valve 4 and the integrated pumping station 81 or 82, it is usually necessary to integrate various control functions in the system into one control system, and through the control system The hardware and software functions of the system collect and manage various detection signals and operation information in the system, so as to control the operation of each controlled component in the system, manage the system operation information, and give early warning and alarm of system failure.

The main advantage of the present invention is that there is no need to maintain a high degree of vacuum at the end of the vacuum pipeline, so there is no need to install a large-volume vacuum energy storage tank or a high-power vacuum pump, which saves investment, reduces the floor area of the pump station and reduces the construction cost. difficulty.

Description of drawings

Figure 1 is a diagram of the installation relationship between the emptying pipe and the water collection tank, vacuum valve, vacuum pipeline, etc.

Fig. 2 is the installation relationship diagram of vacuum pumping station 81

Fig. 3 is the installation relationship diagram of vacuum pumping station 82

Example

The scenic spot in a city covers an area of about 12.5 hectares, and the designed sewage volume is 300 tons/day. The elevation difference in the scenic area is scattered and the lakes are separated. The drainage points in the scenic area are relatively scattered, and it is difficult to collect sewage in a centralized manner. For many years, the sewage cannot be connected to the city's sewage pipe network by itself. Restricted by landscape requirements, it is not suitable to build a vacuum pumping station with a large area and a large amount of work in the scenic area. Adopt technology of the present invention:

(1) A total of 11 water collection tanks 2 are installed in the whole project. The highest elevation of the water collection tanks 2 is 43.40m, and the lowest elevation is 4.90m. The sewage at each drainage point first enters the nearby water collection tank 2 through gravity flow. The volume of each water collection tank 2 is 3m ³ . Set a grille in the water collection tank 2 and set a net at the water outlet connected to the vacuum valve 4 of the water collection tank. to block debris. An emptying pipe 1 is installed at a position 5 on one side where the vacuum valve 4 is connected to the vacuum pipeline 3 , and the emptying pipe 1 is connected to the air 7 through the one-way solenoid valve 6 .

(2) The vacuum pipe 3 includes a branch pipe (DE75), a main pipe (DE110) and a main pipe (DE160). According to the location and distribution of the water collection tanks, combined with the topography and landscape in the park, a total of 3 vacuum main pipes were laid, the longest of which is 610 meters long.

(3) Set up a vacuum pumping station 81 at an elevation of 5.80m, in which the volume of the air-water tank 10 is 2m ³ , the height of the tank is 1.80m, and the maximum liquid level 15 is 0.60m. The vacuum tube 3 is connected to the gas-water tank through the connection port 12, and the connection port 12 is 0.80 meters above the bottom of the tank. The top of the air-water tank 10 is provided with a connecting port 13 connected to the inlet of the vacuum pump 9 . A connecting port 14 is provided at the bottom of the air-water tank 10 to be connected to the water inlet of the drain pump 11 . The vacuum pump 9 uses two water ring vacuum pumps, each with a rated power of 2.35kW and a rated displacement of 80m ³ /h, one for use and one for standby. The drainage pump 11 selects two sewage pumps with a lift of 32 meters, each with a rated power of 5.50kW and a rated displacement of 50m ³ /h.

(4) When the liquid level of each water collection tank 2 reaches 60%, the vacuum valve 4 is opened, and the sewage enters the vacuum pipe 3 . Every 10 minutes after the vacuum valve is opened, the electromagnetic valve 6 is opened once for 10 seconds, and air is replenished in the vacuum tube 3 through the emptying tube 1 . When the liquid level in the collecting tank drops to 30%, the vacuum valve closes.

(5) The system is equipped with a central console to monitor the operation and fault information of each water collection tank, pipeline, valve, gas water tank, vacuum pump, drainage pump, etc., and can remotely control each main component.

The cost of this embodiment is 1/4 of the cost of conventional gravity drainage, and 2/3 of the cost of conventional vacuum maintenance vacuum drainage. This embodiment has been in actual operation for more than one year, the system is stable and trouble-free, and the water and electricity consumption per ton is less than 0.70 degrees. Since the vacuum pipeline is fully sealed, there is no odor or sewage leakage. There is no large-scale excavation during the implementation of the project, and the scenic spot does not need to be closed during the construction period.

Claims (5)

1. the low-pressure drainage system technology for municipal wastewater collection and device, feature is: arrange evacuated tube 1 at connection vacuum water collecting tank 2 with the position of the water outlet side 5 of the vacuum valve 4 of vacuum pipe 3, evacuated tube 1 is communicated with air by unidirectional normally close valve 6, at vacuum valve 4 open period, by the keying of control valve 6 to tonifying Qi in vacuum tube to reduce the requirement to vacuum pipe tip vacuum, as long as pipe network tip relative vacuum degree is less than the requirement that 0 can meet vacuum drainage.

2. low-pressure drainage system technology as claimed in claim 1 and device, feature is: can take following tonifying Qi strategy, at vacuum valve 4 open period, when net tip relative vacuum Du ≥ ?2kPa time, of short duration opening valve 6 to vacuum tube 3 tonifying Qi, opening time of preferred valve 6 be 5 ?15 seconds.

3. low-pressure drainage system technology as claimed in claim 1 and device, feature is: can take following tonifying Qi strategy, at vacuum valve 4 open period, at interval of a period of time of short duration opening valve 6 to vacuum tube tonifying Qi, preferred said interval time be 5 ?15 minutes, time of preferred said of short duration opening valve 6 be 5 ?15 seconds.

4. low-pressure drainage system technology as claimed in claim 1 and device, feature is: when the device adopting following said integrated pumping plant 81 as vacuum occurring source and effluent sewerage, integrated pumping plant 81 is by vacuum pump 9, air hydraulic cylinder 10, drainage pump 11 forms, air pumping out type vacuum pump selected by its intermediate pump 9, high-lift foul water pump selected by drainage pump 11, air hydraulic cylinder 10 is when liquid level 15 keeps a safe distance to prevent water from entering vacuum pump 9 with connector 13, its volume is determined according to the sewage quantity temporarily stored, vacuum power accumulating need not be considered, air hydraulic cylinder 10 also need not sink to installing.

5. low-pressure drainage system technology as claimed in claim 1 and device, feature is: when adopt air water polyblend the device of formula vacuum pump as vacuum occurring source and effluent sewerage time can avoid causing vacuum pump overheated because finding time for a long time.