FI87011C - ELEKTRODAONGPANNA AV VATTENSTRAOLELEKTRODTYP - Google Patents

Description

1 87011

Water jet electrode type electrode steam boiler

The invention relates to a water jet electrode type electrode steam boiler comprising a container containing pressurized steam in a substantially vertically arranged electrically insulated electrode in said container, the electrode having a flow channeling portion for receiving water jet electrode flow; a cylindrical water jet manifold having an inner chamber and an outer surface 10 in a radially spaced vertical line with said channeling member; a plurality of nozzles of a predetermined length forming tubular jets at said manifold, the nozzles having a first end intersecting the outer surface of said manifold and a second open end; a jet outlet defined by a section of the outer surface of said nozzle and manifold.

This invention relates generally to high voltage electric steam boilers, and more particularly to high voltage electric steam boilers using water jet 20 electrodes.

High-voltage electric steam boilers utilizing flowing water or designated "water jet electrodes" have been in use for a considerable period of time. The operation of this type of unit has been described as early as 1935,: '25 Volume XXII, Number 3 of Brown Boveri Review. In this type of unit, water flowing under pressure and directed towards the high voltage electrodes is used to conduct water inside the large pressure vessel with the insulated high voltage electrodes. Generally speaking, units of this type have operated with three sets of high voltage electrodes, applying the widely used three-phase electrical distribution. Typically, these types of units operate at voltages as high as 15,000 volts from stage to stage, generating steam * 35 up to 50 megawatt power supply volumes.

2 87011

Although many steam boilers operating at lower voltages, such as less than 15 kilovolts from stage to stage, are very reliable and produce satisfactory operation, it has been necessary to produce 5 increasing numbers of units to operate at the upper end of the range, e.g. closer to 15 kV, and more recently market demands have necessary to develop units capable of operating at voltages as high as 24 kV phase to phase. This orientation is due to the experience of some electricity users with higher distribution voltages, which allows them to benefit from reduced transmission line costs. An additional market factor, which increases the need for high-voltage operation, arises from the desire of some boiler users to operate 15 directly from the primary distribution circuits in order to overcome the initial costs and operating power losses of the downconverter.

When connecting the boilers to the higher voltages now required, these types of units have encountered an increasing number of internal surges, especially at higher power levels. The Applicant has found that in the models currently used, this overshoot phenomenon is largely due to the interaction of the jets next to the internal steam boiler electrodes, and has developed a new electrode shower-25 alley distribution configuration that substantially avoids the above problems.

Accordingly, it is an object of the present invention to provide an improved high voltage electric steam boiler using a jet electrode capable of operating at a step-by-step level of voltages as high as 25 Kv.

It is a further object of the present invention to provide a water jet formation and an auxiliary jet electrode configuration that minimizes internal breakdowns in the steam boiler due to the interaction of the jets.

. It is a still further object of the present invention to provide a high voltage electric steam boiler using 3 87011 jet electrodes in which the critical dimensions associated with jet generation and high voltage electrical distances are identified and the effects of jet disintegration due to multiple jet collisions are eliminated.

It is a further object of the present invention to provide a high voltage water jet electrode steam boiler in which the critical relationships between water conductivity and jet design / jet electrode ratios are considered. This is achieved by an electrode steam boiler of the type described in the introduction, characterized according to the invention that the first end of the nozzles intersects the outer surface of the nozzle diagonally with respect to the plane defined by the outer surface and that the critical ratio of radial distance to nozzle portion and nozzle length less than 1.88.

The invention also relates to a method according to claim 5 and an electric steam boiler according to claim 6.

20 The use of a water jet electrode trajectory and the separation of an auxiliary high voltage electrode to minimize internal breakthroughs stems from the applicant's observation that the interaction of jets or the dispersion of lower jets is due to to the internal breakthroughs of the steam boiler. Disintegration of the uniform jet causes a widened flow pattern in the vicinity of the High Voltage Electrode Contact. Part of the jet thus dissipated thus has a shortened distance of the flight path or path to the edge of the electrode. At this shortened distance, the breakdown voltage is substantially reduced. The unitary jet, which applies to the electrode on its farthest surface, thus has a higher dielectric strength, which minimizes breakthrough or pum-dents.

4 67011

Applicant's finding has yielded results in the development of a water jet manifold whose length has been increased to a critical value at an equally critical cutting angle with the associated manifold wall. This combination, when mounted on a somewhat modified end, produces a vertical jet pattern that allows the jet to be reconnected in the flow channel portion of the receiving high voltage electrode. The jet disturbance is thus minimized and the subsequent generation of random flow patterns of mixed water around or outside the electrode flow channel is substantially eliminated.

As stated above, it is precisely this shortened flow path used in currently produced steam boilers that the applicant has found to contribute to the efficiency of the steam boiler by reducing the dynamic internal distance of the steam boiler under flow conditions associated with power outputs, especially when operating close to maximum steam.

The use of the composite structure described herein and patent pending allows steam boilers. operation at substantially higher distribution voltages with acceptable internal arc discharges and greatly reduce internal arc or steam boiler "shocks" in existing low voltage units.

Other objects and advantages of the invention will become apparent upon reading the following detailed description and with reference to the figures, in which:

Figure 1 is a partially sectioned view of a conventional ve-jet electrode steam boiler, showing in particular the ve-jet jet manifold and high voltage electrode in section.

Fig. 2 is a sectional view of the steam boiler of Fig. 1 taken along lines 2-2, showing in particular the rupture of a water jet electrode generation and collision with a high voltage electrode for channeling or collecting high voltage for one phase.

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Figure 3 is a sectional view of an electric steam boiler using a water jet electrode, similar to Figure 3a, but constructed in accordance with the objects and principles of the present invention.

Fig. 3a is a partial section of a steam boiler having a high voltage electrode, showing the relationship between the receiving electrode and the manifold, and in particular showing the trajectory of the interfering jets present in typical units currently in use.

Fig. 4 is a cross-sectional view taken along lines 4-4 of Fig. 3, showing in particular the formation of a conventional water jet electrode, where a collision or collision of the jet produces an electrical breakthrough.

Although an improved electric steam boiler of the invention will be described in connection with the preferred embodiment shown, it is to be understood that this particular embodiment is not intended to limit the invention to this embodiment. On the contrary, it is intended by the applicant to cover all alternatives, variations and equivalents which may be included within the spirit and scope of the invention as defined in the appended claims.

Referring in particular to Figures 1 and 2, the steam boiler consists of an outer tank or pressure vessel 2 containing a jet electrode feed water main group 4 which feeds water, which in turn water jet electrodes 6 from water flowing through a plurality of nozzles 8. Inside the boiler pressure vessel or tank are also high voltage electrodes 10. Typically, three-phase power is used to generate steam, so three internal high voltage electrode assemblies 10 cooperating with three groups of nozzles or jet electrodes 8 are shown as described (referring to Figure 2). The assemblies 10 include a high voltage supply through an insulator 13 which provides a pressure insulating electrical circuit supplying current from the ul-35 power source to the internal electrode 10. More specifically, the flow of electric current through the insulator 13 provides energy to the electrode flow channel 11. The jet electrodes 6 , start heating the water. It should be noted that Figure 1 shows, for the sake of clarity, one group of nozzles 8, water jet electrodes 6 and high voltage receiving electrodes 10. Inside the high pressure steam boiler tank there is also a feed water pump 12 dispensing part with internal parts of its housing 14 with inlet 16 and an outlet 10 terminating in a feed water distribution pipe 18. Between the pump outlet and the pipe 18 is a control valve and an actuator assembly 20 having an actuator outside the tank 2 using a valve closure 24. As will be shown later, the placement of the part 24 controls the supply of water 15 to the pump 12 to the head 4.

As shown (referring to Figure 1), the feed water distribution pipe produces a sufficient level of water, typically two, inside the head 4 to cause water to flow outward from the nozzles 8 forming the spray electrodes 6, 20 which collide with the high voltage receiving electrode 10.

Figures 3 and 3a show a partial cross-section of the formation of the spray electrode and the construction of the high voltage electrode. Each construction utilizes, as in the unit described above, a pressurized container 2 containing a high voltage electrode assembly 10 fed by a high voltage through an inlet sleeve 13 insulated from the terminal 15 and connected to a water jet duct portion 11. Centrally located in the container 2 are 30 jets , comprising a cylindrical part with a plurality of vertically arranged openings terminating an associated plurality of flow control nozzles 8 disposed within the main group 4. Each nozzle 8 has an open end in communication with the water level 22 of the cylindrical part 35 of the head, and an end terminating in the opening 5 forming the jet.

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In operation, referring to Fig. 3a, with the head water level as indicated by reference 38, the flow of feed water out of the vertically located openings provides a vertical column of water jet electrodes 5 passing between the cylindrical manifold surface 37 and the inner or flow channeling portion 11 of the electrode assembly 10. 49 across.

As shown, the flight paths of the jet electrodes from the high level 39 to the low level 40 produce a disturbance or jet intersection typically occurring in the area indicated by reference numeral 41. In addition, referring to Fig. 4, jet collisions produced in the intersection area 41 cause a substantial spread of water now the resulting flow, i.e., a coarse jet having components 39 and 40. The jet collision changes the original jet size to the extent that deflected jets having a jet component 42 of jet components 39 and 40 are produced.

20 Under these conditions, a feed water with an electrode ... the potential 1 close to the electrical potential of the manifold 4 is now directed towards the outer surface portion 49 of the flow guide 17. When the electrode assembly 10 operates at the phase voltage potential, current flows through the jet 25 along a path 43 having a length 49. Because this path is substantially shorter than a straight path 48 , a breakthrough occurs between the electrode surface 49 and the distribution head surface in the vicinity of the area indicated by reference numeral 3. This flow causes a greatly reduced breakthrough distance and subsequent arcs, denoted by reference numeral 43.

Applicant's observation of the jet collision phenomenon has resulted in the jet electrode formation and high voltage electrode structure described herein, particularly shown in Figure 3. Referring to Figure 3 and as discussed above, the electrode assembly 10 and manifold 4 are located within the pressure vessel or container 2. The distribution head unit 4 uses a plurality of spray nozzles 8 which terminate at one end in the flow control openings 5 and which are at their opposite end in flow communication with the supply water of the distribution head. As shown, the tubular axis of the nozzle 8 is inclined at a critical angle 46 to a plane perpendicular to the surface 37 of the manifold. In addition, the critical lengths developed include the distance between the nozzle length 47 and the cylindrical surface 37 of the manifold head and the high voltage electrode flow channeling surface 11, indicated by reference numeral 48. As further indicated in Figure 3, using critical constants defined by the applicant, the upper jet electrode 39 and 15 the lower jet trajectory 40 joins or assembles a substantially larger vertical portion of the electrode surface 11. It has also been determined that jet impacts or cuts, such as 41, are greatly reduced or non-existent, thereby eliminating arcing tendencies caused by electrode shower- ... with different speed components 42 (Refer to Figure 4).

Applicant has also found that an increased area of the jet assembly, i.e., 41 relative to the current flow, produces a substantially reduced current density on the surface 11 of the electrode assembly 10. Local heating and electrode deterioration are thus substantially reduced. A continuing problem with currently used jet electrode steam boilers is the generation of hydrogen (H2) and oxygen (O2) on the electrode-30 surfaces. It is well known that a reduced electrode current density minimizes gas formation through increased recombination. Improved recombination is thus reflected in reduced hydrogen and oxygen generation.

The application of the Applicant's observation in the form of the described embodiment has resulted in a substantial improvement in the operation of the high voltage jet electrode steam boiler. The applicant has observed a 67% increase in operating voltage and a 50% increase in steam boiler capacity without increased power requirements for the jet electrode feed water pump.

Typical Applicant-Defined Critical Constants that produce the above improvements in steam boiler operation are a 22.8 cm jet electrode nozzle length and a 30 ° angle between the nozzle axis and a horizontal radius perpendicular to the cylindrical surface of the manifold. The distance 48 between the high voltage electrode and the surface of the manifold outlet, in accordance with the applicant's inventive ideas, is 41.9 cm.

The steam boiler further includes a flow portion 26 terminating at the lower end of the high voltage electro-15 dicho assembly 10 which channels the combined water flow 24 from the jet electrodes 6 toward the return water counter electrode or gate 30 operating at the ground potential of the tank or power supply. The channeled water from the spray electrode passes through the counter electrode, returning to the lower part of the tank, where, typically, is maintained. . during operation return water level 32.

It will be readily apparent to those skilled in the art of electric steam boilers that all feed water to the jet electrodes in the electrode steam boilers is maintained at a precisely controlled value of electrical conductivity by the use of added chemicals.

The applicant has further found that operation at a voltage of 20 kV electrode allows the conductivity of the feed water to be reduced from the normally used value of 2,000 micromho to about 1,700 micromho, which still reaches 50% growth at the boiler outlet. Those skilled in the art of the electric steam boiler will immediately appreciate that this decrease in the conductivity of the jet electrode feedwater is further reflected in the reduction in the amount of hydrogen and oxygen formation on the surface 11 of the steam boiler high voltage electrode assembly.

35 Those skilled in the art of electric boilers will readily appreciate that a number of conventional steam boiler auxiliary controls, such as water level indicator, feed water inlet, pressure relief valve, and others, are as shown and indicated in Figures 1 and 2 below. components do not form part of the invention, this does not include any further explanation of their operation.

In operation, the water in the pressurized tank 2 of the steam boiler at level 32 enters the pump inlet 16 and is transferred to the manifold 4 via the pump outlet pipe 18. The level 22 of the water 10 essentially determines the amount of steam emission of the steam boiler to be transmitted to the load, since the amount of jet electrodes 6 generated is directly proportional to the water level 22 at the manifold 4. The conductivity feed water in the nozzles 8 forms the jet electrode 15 , strikes or impinges on the center portion 11 of the high voltage electrode assembly 10 (referring to Figure 2). Since the tank 2 and the nozzles 8 operate at a substantially neutral ground potential, while the high voltage electrode operates at the phase voltage of the electric power source, the conductive water of the jet 6 is heated by an electric current, which generally raises its temperature and generates steam. As stated above, the amount of steam generated and, to a certain extent, its pressure is directly determined by the number of jets and the amount of water in the nozzles is determined by the water level at the manifold. When only a small amount of water from the spray electrode is heated to a temperature high enough to generate steam, the accumulating water flow from the nozzles 8 and jets 6, which now flows vertically downward in the flow channel 11 of the high voltage electrode assembly 10, exits the high voltage 30 at point 26. is the return water of the shower electrode substantially at the electrical potential of the high voltage electrode. Thus, as shown, the flow leaving the electrode passes through the return water counter electrode 30. Since the electrode 30 is at a neutral ground or fiber 35 potential, the electric current flowing through the outlet stream 11 8701 1 increases steam in the return stream 28. All non-vaporized water returns to the lower portion of the tank 2, typically maintaining level 32. The volume of water in the level 32 is functional it serves as a 5 "silencing" or silencing volume in an effort to reduce turbulence at the pump inlet.

Thus, it is apparent that an improved high voltage steam boiler using a water jet electrode has been produced in accordance with the applicant's findings and the invention, which fully satisfies the objects, goals and advantages previously set forth. Although the improved water jet / high voltage electrode structure shown has been described in connection with a particular unit, the applicant emphasizes that many alternatives, modifications, and variations will be apparent to those skilled in the art of electric steam boilers in light of the applicant's foregoing description. Accordingly, the applicant seeks to cover all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.

Claims (8)

A water jet electrode boiler which comprises a container (2) containing compressed air filled meadow; a substantially vertically positioned electrically isolated electrode (10) in said container (2), said electrode having a flow channeling portion for receiving a jet electrode flow (6); a cylindrical water jet dividing head (4) having an inner chamber and an outer surface in radially separate vertical line with said channel portion; a plurality of nozzles (8) of predetermined length forming tubular jets (6) in said dividing head (4), said nozzles having a first end which cuts the outer surface of said dividing head, and a second open end; a jet outlet opening (5) defined by the cutting for said nozzle (8) and the outer surface of the dividing head (4), characterized in that the first end of the nozzles intersects the outer surface of the dividing head (4) obliquely in relation to one defined by the outer surface. , and that the critical ratio of the radial distance between the outer surface of the dividing head and said flow channeling portion to the length of the nozzle is less than 1.88. Steam boiler according to claim 1, characterized in that the inclined cutting angle between the nozzle (8) and the outer surface of the dividing head (4) is substantially 60 °. Steam boiler according to claim 1, characterized in that the length of the jet nozzle (8) is substantially 22.8 cm. 35 Steam boiler according to claim 1, characterized in that said radial distance is substantially 40.6 cm. 5. A method for reducing the current density of a high voltage electrode contact area in a water jet type electric boiler with a plurality of vertically arranged jets (6) nozzles (8) and a vertical high voltage electrode (10) adjacent to them, in that it comprises the following steps: extension of the water jet nozzle (8); Increasing the pitch angle of the water jet (6); placing the electrode (10) on the trajectory of the water jet (6) to catch the water jet at a point where the intersection of the water jet (6) is minimal, so that the contact area of the water jet (6) on the surface of the high voltage electrode (10) is maximized. 6. Electric jet electrode boiler, comprising a container (2) containing compressed air filled meadow; A vertically arranged high voltage electrode (10) in said container (2), said electrode having a beam contact surface (11) between the flow scanner edges; a vertically arranged, substantially cylindrical feed water dividing head (4) having an inner chamber and an outer surface, said outer surface being vertically aligned with and on a predetermined radially spaced from said contact surface (11) and flow scaling edges; a plurality of vertically located nozzles (8) of predetermined length forming tubular jets (6) in said dividing head (4), said nozzle (8) cutting the surface of the dividing head (4) obliquely at its first end, the other end is open to said chamber, characterized in that said angle and length determine the flight path of the falling beam, so that the successively vertically falling bars like said distance and the flight paths of the jets intersect at predetermined angles , wherein the intersections of the beams form a composite beam electrode, the intersection of said composite beam and the contact surface being located within said channel edges. 7. A water jet electric steam boiler according to claim 6, characterized in that said plurality of vertically located nozzles (8) forming a tubular jet comprise at least the four uppermost nozzles of the dividing head (4). 8. Water jet electric steam boiler according to claim 7, characterized in that the length of the nozzle is 22.8 cm, that the oblique cut is 30 ° and that the length of the electrode is substantially 190.5 cm.