RU2775981C1 - Pressure centrifugal vortex deaerator (2 options) - Google Patents

Abstract

FIELD: heat engineering.

SUBSTANCE: invention relates to heat engineering; it can be used for removal of gases from nutrient water of heating and hot water supply systems. A pressure centrifugal vortex deaerator contains cylindrical case 1 with centrifugal swirler 2. According to the invention, on the lower surface of fixed disc 3 of centrifugal swirler 2, mesh cylindrical surfaces 5 are fixed, arranged in concentrical rows, facing movable disc 11. In the body of fixed disc 3, holes 4 are formed for release of a steam-air mixture to cavity 10 above fixed disc 3, connected to branch pipe 9 for removal of the steam-air mixture. Branch pipe 8 for source water supply is located in the upper part of cylindrical case 1 above fixed disc 3, and its free end is curved and passed to a gap formed between drive shaft 6 and an inner edge of fixed disc 3 for source water supply directly to movable disc 11. In close proximity to bottom 15 of cylindrical case 1, annular cavity 16 is formed in its sidewalls, in which pressure blades 22 are located, fixed along an outer edge of movable disc 11. On movable disc 11, near drive shaft 6, in recesses between annular protrusions 12 and in front of pressure blades 22, accelerating blades 14 are additionally fixed. According to the second option, centrifugal swirlers 2 are located one above the other. Pressure blades 22 located in annular cavity 16 are fixed along the edge of drive disc 17 mounted at the end of drive shaft 6, and accelerating blades 14 are fixed in front of an input to annular cavity 16 on drive disc 17. Between movable disc 11 of lower centrifugal swirler 2 and drive disc 17, intermediate cavity 23 is formed.

EFFECT: increase in functionality, and simplification of deaeration installations, significant reduction in dimensions, increase in the performance, increase in the reliability of device operation.

8 cl, 4 dwg

Description

The invention relates to thermal power engineering and can be used to remove gases from the feed water of heating and hot water supply systems.

Deaeration plants are used at thermal power plants (TPPs) and boiler houses to prevent corrosion of power equipment by removing corrosive gases from water. Along with the traditional designs of deaeration plants, such as jet, bubbling, film, nozzle, centrifugal-vortex deaerator (DCV) is currently gaining more and more popularity, in which it was possible to significantly intensify the mass transfer process due to the vortex organization of the flow in the working area. Taking into account the ease of manufacture, low metal consumption of deaeration elements, a wide range of regulation of work loads, simplicity and safety of operation, such deaerators are promising, including at power plants where DCVs are installed as the first stage of deaeration plants for feeding the heating network and additional water of the cycle. In this regard, conducting experimental studies of the processes of formation of the interfacial surface and heat and mass transfer in centrifugal vortex deaerators in order to increase their efficiency by improving designs, technological modes and switching schemes is relevant. The scope of research aimed at improving the energy efficiency of deaeration equipment corresponds to the priority areas of development of science, technology and engineering.

Known vortex deaerator (RU 76017, IPC 6 S02F 1/20, 2008), including a cylindrical body with end caps, one of which has an axial hole and/or branch pipe, while on the side surface of the housing next to the cover having an axial hole, is located outlet(s) and/or spigot near the opposite cover. An inlet pipe is tangentially connected to the side surface of the body, and between them, closer to the outlet, there is a partition containing at least one hole made near the side surface of the cylindrical body. The vortex deaerator can be equipped with a flow swirler made in the form of a volute.

The disadvantage of the known vortex deaerator is the impossibility of working in the vacuum deaeration mode at low temperature of the source water, the impossibility of supplying deaerated water to the consumer in the heating system with back pressure, which leads to a decrease in the quality of deaeration at elevated pressure in the deaerator housing due to the reverse dissolution of the evolved gases.

Known vacuum deaerator NETZSCH DA / DA-VS, containing a deaeration chamber with a rotating disk located in it without swirling elements, a pipe for supplying the initial liquid, a pipe for deaerating liquid. (www.netzsch-grinding.com).

The disadvantage of such a deaerator is the low degree of swirling of the liquid flow due to the absence of swirling elements, a small flow range of the deaerated liquid due to the need to maintain a thin layer on a rotating disk, and the need for an additional pump to feed the system with back pressure.

Known cavitation-jet deaeration plant RU 2008120170, IPC 6 C 02 F 1/20, 2009), containing a centrifugal swirler and a fairing located in the tubular body of the deaerator, to which the pipelines of the source and deaerated water are connected, the water vapor mixture pipeline connecting the cavity between the swirler and a fairing with an ejector, a regulating body included in the pipeline of the water-vapor-air mixture. The plant is equipped with a water-vapor-air mixture structure regulator connected to a sensor of residual oxygen content in deaerated water and with a regulator included in the water-vapor-air mixture pipeline, which forms the structure of the discharged water-vapor-air mixture.

The disadvantage of the known installation is the need to use a pump to supply deaerated water to the consumer. Cavitation-jet deaerators use only the energy of the movement of a water jet for cavitation, which does not provide deep removal of dissolved gases, which is necessary to ensure the norms for dissolved oxygen for heating networks.

As a prototype, a centrifugal-vortex deaerator (RU 123407, IPC C02F 1/20, 2012) was chosen, containing a cylindrical body with a centrifugal swirler, a source water supply pipe, a deaerated water outlet pipe and a steam-air mixture outlet pipe. The centrifugal swirler of the deaerator is made up of a fixed part rigidly fixed on the cylindrical body of the deaerator, made in the form of an inverted cup with a flange, and a drive disk. The output shaft of the drive is rigidly fixed on the outer surface of the bottom of the cup, in the bottom of which there is a hole for the passage of the output drive shaft. At the end of the shaft, a drive disk is rigidly fixed with at least two concentric rings rigidly fixed on its surface from the sleeve flange side. At least one annular row of rigidly fixed guide vanes is located on the surface of the cup flange from the side of the drive disk, and an annular row of rigidly fixed swirl vanes is located on the surface of each of the concentric rings of the drive disk. The source water supply pipe is located in the wall of the centrifugal swirler cup. Concentric rings with a corresponding annular row of swirl blades of the drive disk are located relative to each other with the possibility of free placement between them of a row of guide vanes of the cup flange. The drive disk is installed so as to enable successive passage of initial water from the cavity of the centrifugal swirler glass to the inner wall of the deaerator housing. The deaerated water outlet pipe is located in the bottom part of the deaerator, and the steam-air mixture outlet pipe is located inside the deaerator body and led out through its bottom, and the intake part of the steam-air mixture outlet pipe is located in the upper part of the deaerator body. Each of the concentric rings is made protruding above the surface of the drive disk to a height greater than the gap between the surface of the drive disk and the lower end of the guide vanes of the cup flange. Each of the swirling blades is made in the form of a flat or curved plate, placed at an angle to the radius drawn to it from the axis of rotation, with the possibility of a rapid increase in the rotation speed of the source water jets arriving at them. Each of the guide vanes of the cup flange is made in the form of a flat or curved plate placed at an angle to the radius drawn to it from the axis of rotation, in order to quickly stop the water jets coming from the swirling vanes of the drive disk of the centrifugal swirler.

The disadvantage of the known installation is the presence of a large storage capacity and the need to use a pump to supply deaerated water to the consumer. In addition, when operating in the vacuum deaeration mode at low temperatures of the source water, its use is difficult due to the need for a difference in the heights of the deaerator and pump, because the close location between them negatively affects the stability of the pump, which, in turn, also leads to an even greater increase in the dimensions of the installation, material consumption, complication of the design and its operation. The known design is unacceptable for small-sized block-modular boilers.

The problem to which the invention is directed is the development of a centrifugal-vortex deaerator design for the possibility of its use in small-sized multifunctional block-modular boiler houses by combining the deaeration process and water supply to consumers in one device.

The technical result of the invention is the simplification of deaeration plants by eliminating the storage tank for deaerated water and the pump for supplying water to the consumer, increasing productivity by expanding the range of allowable water flow rates for deaeration, including low-temperature vacuum deaeration, increasing the reliability of the device, as well as expanding arsenal of technical means aimed at water deaeration.

According to the first variant, the technical result is achieved due to the fact that the pressure centrifugal-vortex deaerator contains a cylindrical housing with a centrifugal swirler, including a fixed disk fixed in the housing and, fixed on the drive shaft, connected to the drive, a movable disk made with annular protrusions on which swirl blades are fixed, facing towards the fixed disk, as well as pipes for supplying source water, draining deaerated water, and draining the steam-air mixture. According to the invention, mesh cylindrical surfaces arranged in concentric rows facing the movable disk are fixed on the lower surface of the fixed disk. Holes are formed in the body of the fixed disk for the outlet of the vapor-air mixture into the cavity above the fixed disk, which is connected to the steam-air mixture outlet pipe. The source water supply pipe is located in the upper part of the cylindrical body above the fixed disk, and its free end is bent and inserted into the gap formed between the drive shaft and the inner edge of the fixed disk to supply source water directly to the movable disk. In the immediate vicinity of the bottom of the cylindrical body, in its side walls, an annular cavity is formed, in which pressure blades are located, fixed along the outer edge of the movable disk, while accelerating blades are additionally fixed on the movable disk near the drive shaft, in the recesses between the annular projections and in front of the pressure blades. shoulder blades. The annular cavity is connected to the deaerated water outlet pipe, which is tangentially mounted on the side wall of the housing and oriented in the direction of deaerated water movement.

The swirling and accelerating blades of the movable disk are fixed in such a way that they freely pass into the gaps between the rows of mesh cylindrical surfaces of the stationary disk.

Mesh cylindrical surfaces preferably include from 1 to 5 concentric rows.

The holes for the exit of the vapor-air mixture are preferably located in the intervals between the concentric rows of mesh cylindrical surfaces.

The accelerating vanes installed in the recess between the annular ledges of the movable disk and in front of the pressure vanes can be made bent in the direction of disk rotation.

The height of the mesh cylindrical surfaces of the stationary disk is chosen based on the possibility of free passage between them of the swirling blades of the movable disk.

The presence on the lower surface of the fixed disk mesh cylindrical surfaces, which are arranged in concentric rows facing the movable disk, allow, unlike the prototype, to increase the degree of dispersion of water jets from the swirl blades and thereby improve the process of water deaeration. Making holes in the body of the fixed disk facilitates the exit of the vapor-air medium formed in the process of water deaeration into the cavity above the fixed disk and further into the steam-air mixture outlet pipe, which also improves the deaeration process, because timely removal of released gases prevents their reverse dissolution in water.

The execution of the source water supply pipe and its location above the fixed disk ensures the supply of water to the initial position for deaeration and creates conditions for the successive passage of water through all stages of deaeration.

The presence in the recesses between the annular ledges of the movable disk, as well as near the drive shaft, and in front of the pressure blades of the accelerating vanes in combination with the swirl vanes, can significantly speed up the process of water deaeration due to the timely removal of water from the recesses between the annular protrusions of the movable disk of the swirling blades, which significantly increases deaeration performance and improves quality, as there is no overflow of centrifugal swirler with water.

The execution in the cylindrical body of the annular cavity, in which pressure blades are located, fixed along the edge of the movable disk, together with the placement of the bottom of the body in close proximity to the annular cavity, makes it possible to exclude the use of an additional booster pump for supply to the consumer. Thus, the accumulative capacity is excluded, and, consequently, the dimensions of the installation are significantly reduced, in comparison with known devices, and the functionality of the installation is expanded.

The location of the deaerated water outlet pipe tangentially to the annular cavity, oriented in the direction of deaerated water movement, ensures a minimum pressure loss when water passes from the annular cavity to the deaerated water outlet pipe, which is especially necessary for vacuum deaeration, when there is a reduced pressure inside the housing.

According to the second version, the pressure centrifugal-vortex deaerator, unlike the first version, includes several centrifugal swirlers, which are located in a cylindrical housing one under the other. Each centrifugal swirler is equipped with a source water supply pipe and a steam-air medium outlet pipe. On the movable disk near the drive shaft, in the recesses between the annular ledges and in front of the pressure blades, the accelerating blades are additionally fixed. Each fixed disk is fixed on the side wall of the housing on supports to form a gap between the housing wall and the edge of the fixed disk for the passage of deaerated water. On the side walls of the cylindrical body, directly near the bottom of the body, an annular cavity is formed, in which pressure blades are located, fixed along the edge of the drive disk mounted at the end of the drive shaft, and accelerating blades are fixed on the drive disk in front of the entrance to the annular cavity. An intermediate cavity is formed between the movable disk of the lower centrifugal swirler and the drive disk to prevent the swirlers from overflowing with water and getting deaerated water into the steam-air mixture outlet pipe.

The installation of fixed disks on supports with the formation of a gap between the side wall of the cylindrical body and the edge of the fixed disk is necessary for the unhindered passage of water from the accelerating vanes of the movable disk of each swirler down the side walls of the body to the drive disk and further into the annular cavity.

The presence of a drive disk with pressure blades installed along its edge and located in the annular cavity, as well as the installation of additional accelerating blades on the drive disk in front of the pressure blades provide a quick removal of deaerated water from the deaerator housing, creating pressure in the annular cavity even in the presence of vacuum inside the deaerator housing , the possibility of supplying deaerated water directly to the heating network or to the consumer with back pressure without an additional pump.

The presence of an intermediate cavity contributes to the creation of conditions for the timely operation of automation and a decrease in the water supply in case of a possible imbalance in the supply and discharge of water to the deaerator to ensure a stable deaeration mode, prevent overflow of swirlers with water and ingress of deaerated water into the steam-air mixture outlet pipe.

Several centrifugal swirlers can be located in the cylindrical body, the number of which depends on the performance of one swirler and the total required performance of the installation, and usually ranges from 2 to 5.

The invention is illustrated in the following drawings, where in FIG. 1 shows a pressure centrifugal vortex deaerator according to the first variant; in fig. 2 - section along A-A; in fig. 3 - pressure centrifugal-vortex deaerator according to the second variant; in fig. 4 - section along A-A.

In the drawings, positions indicate:

1 - cylindrical body;

2 - centrifugal swirler;

3 - fixed disk;

4 - holes for the exit of the steam-air mixture;

5 - mesh cylindrical surfaces arranged in concentric rows;

6 - drive shaft;

7 - drive;

8 - pipe for supplying source water;

9 - branch pipe for the removal of the steam-air medium;

10 - cavity formed above the fixed disk 3;

11 - movable disk;

12 - annular protrusions of the movable disk 11;

13 - swirl blades mounted on the annular ledges 12;

14 - accelerating blades fixed in the recesses between the annular protrusions 12 and in front of the pressure blades;

15 - the bottom of the cylindrical body 1;

16 - annular cavity;

17 - drive disk;

18 - branch pipe for the removal of deaerated water;

19 - supports on which fixed disks 3 are fixed;

20 - gap between the wall of the housing 1 and the edge of the fixed disk 3;

21 - additional accelerating blades;

22 - pressure blades;

23 - intermediate cavity.

The pressure centrifugal-vortex water deaerator according to the first version is designed to operate on a low-pressure or non-pressure consumer (storage tanks under atmospheric or low pressure, systems with low back pressure) and operates as follows.

The drive motor 7 is turned on. The movable disk 11, mounted on the drive shaft 6, spins. The source water is fed through the pipe 8 of the water supply directly to the inner edge of the movable disk 11, on which the water is captured by the accelerating blades 14, rises above the annular protrusion 12 of the movable disk 11, is captured by the rotating swirl vanes 13 and accelerates, receiving significant kinetic energy. High-speed jets of water after the blades 13 fall on the stationary mesh cylindrical surfaces 5 of the fixed disk 3 located in concentric rows, where they break and sharply reduce the speed, experiencing significant cavitation phenomena and overloads, as a result of which the vapor-gas fraction is released and separated from the water. The gas-vapor mixture enters the cavity 10 and is then removed from the housing 1 through the pipe 9 into the atmosphere during atmospheric deaeration or is pumped out by a vacuum pump during vacuum deaeration. The decelerated jets of deaerated water after the last concentric row of the mesh cylindrical surface 5 flow down under the action of gravity, are thrown by the accelerating blades 14 onto the pressure blades 22, and through the deaerated water outlet pipe 18, the deaerated water enters consumers.

If the consumer's heating network is under pressure, and this is the most common case, and a larger range of make-up flow rates is required, a centrifugal-vortex deaerator is used according to the second variant with a drive disk 17 and an intermediate cavity 23.

The device according to the second variant works as follows.

The source water is supplied through pipes 8, located above each fixed disk 3, to the movable disks 11. Water deaeration in swirlers 2 occurs similarly to the first option. In this case, the deaerated water, which has passed the deaeration process in each centrifugal swirler 2, flows down the side wall of the cylindrical body 1 through the gaps 20 to the drive disk 17, where it first falls on additional accelerating blades 21, then on pressure blades 22 in the annular cavity 16, where the water is accelerated to a speed that provides sufficient pressure in the nozzle 18 and its supply to the consumer through the nozzle 18 for the removal of deaerated water without additional intermediate pumps.

If the discharge of deaerated water decreases due to an increase in counterpressure in the outlet 18 of the outlet of deaerated water, an excess of water will appear in the intermediate cavity 23 and the automation will immediately reduce the supply of source water for deaeration, eliminating the overflow of the deaerator and the ingress of water into the outlet 9 of the outlet of the steam-air mixture. The volume of the intermediate cavity 23 must be sufficient for reliable operation of the automation and is approximately equal to the volume of water at the maximum estimated flow rate in 5-10 seconds. For example, for a maximum estimated water flow of 5 m ³ per hour, the volume of the intermediate cavity 23 is in the range of 7 - 14 dm ³ . For example, the volume of the storage tank for such a water flow is usually more than 1000 dm ³ .

The use of the claimed pressure centrifugal-vortex deaerator of water can significantly reduce the dimensions due to the lack of a storage tank and the need to create a hydrostatic head necessary for the operation of the pumping pump during vacuum deaeration, eliminate the use of an additional pump for pumping deaerated water and supplying it to consumers, increase reliability and simplify control the process of deaeration and its supply to consumers in one device, to expand the range of allowable water flow rates for deaeration, which significantly increases the functionality of the deaerator and the possibility of using it in the vacuum low-temperature deaeration mode in small-sized block-modular boiler houses.

Claims (8)

1. Pressure centrifugal-vortex deaerator, containing a cylindrical housing with a centrifugal swirler, including a fixed disk fixed in the housing, and a movable disk fixed on the drive shaft associated with the drive, made with annular protrusions on which the swirling blades are fixed, facing towards the fixed disk , pipes for supplying source water, draining deaerated water and draining the steam-air mixture, characterized in that mesh cylindrical surfaces are fixed on the lower surface of the fixed disk, located in concentric rows facing the side of the moving disk, holes are formed in the body of the fixed disk for the steam-air mixture to exit into the cavity above the fixed disk, connected with the steam-air mixture outlet pipe, the source water supply pipe is located in the upper part of the cylindrical body above the fixed disk, and its free end is bent and inserted into the gap formed between the drive shaft and the inner edge m of a fixed disk for supplying source water directly to the movable disk, in addition, in the immediate vicinity of the bottom of the cylindrical body, an annular cavity is formed in its side walls, in which pressure blades are located, fixed along the outer edge of the movable disk, while on the movable disk near the drive shaft, in the recesses between the annular protrusions and in front of the pressure blades, accelerating blades are additionally fixed, and the annular cavity is connected to the deaerated water outlet pipe, which is tangentially mounted on the side wall of the housing and oriented in the direction of deaerated water movement. 2. Deaerator according to claim 1, characterized in that the swirling and accelerating blades of the movable disk are fixed in such a way that they freely pass into the gaps between the concentric rows of mesh cylindrical surfaces of the fixed disk. 3. Deaerator according to claim. 1, characterized in that the mesh cylindrical surfaces include from 1 to 5 concentric rows. 4. Deaerator according to claim 1, characterized in that the holes for the exit of the vapor-air mixture are located in the gaps between the concentric rows of mesh cylindrical surfaces. 5. Deaerator according to claim. 1, characterized in that the accelerating blades, fixed in the recess between the annular ledges of the movable disk, are made curved in the direction of rotation of the disk. 6. Deaerator according to claim 1, characterized in that the height of the mesh cylindrical surfaces of the fixed disk is selected based on the possibility of free passage between them of the swirling blades of the movable disk. 7. Pressure centrifugal-vortex deaerator, containing a cylindrical body with a centrifugal swirler, including a fixed disk fixed on the body, and a movable disk fixed on the drive shaft associated with the drive, made with annular protrusions, on which swirl blades are fixed, facing towards the fixed disk , pipes for supplying source water, draining deaerated water and draining the steam-air mixture, characterized in that in the cylindrical body the centrifugal swirlers are located one below the other, while each centrifugal swirler is equipped with a pipe for supplying source water and a pipe for removing the steam-air medium, each pipe for supplying source water is located above the corresponding fixed disk, and its free end is bent and inserted into the gap formed between the shaft and the inner edge of the fixed disk, to supply source water directly to the movable disk, mesh cylinders are fixed on the lower surface of each fixed disk Dried surfaces located in concentric rows facing the movable disk, with each fixed disk fixed on the side wall of the housing on supports with the formation of a gap between the housing wall and the edge of the fixed disk for the passage of deaerated water, holes are formed in each stationary disk for the exit of the steam-air mixture accelerating blades are additionally fixed on the movable disk near the drive shaft, in the recesses between the annular projections and in front of the pressure blades, accelerating blades are additionally fixed on the side walls of the cylindrical housing directly near the bottom of the housing, an annular cavity is formed in the cavity formed above the fixed disk, in which pressure vanes are located, fixed along the edge of the drive disk mounted on the end of the drive shaft, and in front of the entrance to the annular cavity, additional accelerating vanes are fixed on the drive disk, the annular cavity is connected to the branch pipe outlet of deaerated water, which is tangentially mounted on the side wall of the housing and oriented in the direction of movement of deaerated water, in addition, between the movable disk of the lower centrifugal swirler and the drive disk, an intermediate cavity is formed to prevent overflow of the swirlers and ingress of deaerated water through the gaps into the steam-air mixture outlet pipe. 8. Deaerator, according to claim 7, characterized in that in the cylindrical body there are from 2 to 5 centrifugal swirlers.

Images