JP6366104B2 - Steam generator - Google Patents

Description

  The present invention relates to a steam generator used in a steam convection oven or the like.

  Patent Document 1 below discloses a heating cooker that heats and cooks food with hot air containing steam. The heating cooker includes a cooking chamber that stores food, a heater that heats the inside of the cooking chamber, a fan that circulates air in the cooking chamber, and a steam generator that supplies steam to the cooking chamber. The food housed in the cooking chamber is cooked by circulating air heated by a heater together with the steam supplied from the steam generator by a fan.

  The steam generator of the heating cooker includes a steam generating container that stores water of a predetermined water level, a heating means that heats water in the steam generating container, and a lower part of the steam generating container that is in communication with the steam generating container. A water level detection tank for detecting the water level, a water level sensor provided in the water level detection tank, and a water supply pipe connected to the water level detection tank are provided. In this steam generator, the water supplied into the water level detection tank flows into the steam generation container so that the water level is the same as that of the water level detection tank, and the water that has flowed into the steam generation container is heated by the heating means. And sent to the cooking chamber. Although the water in the steam generation container gradually decreases due to the generation of steam, the water in the water level detection tank flows into the steam generation container so that the water level becomes the same as the water level of the water level detection tank. The water in the water level detection tank gradually decreases because it flows into the steam generation container, but the water level detection tank is supplied with water from the water supply pipe so as to reach a predetermined water level based on detection by the water level sensor.

JP 2013-200111 A

  The steam generator of Patent Document 1 described above is generally provided with a cylindrical overflow pipe that discharges excess water level in the water level detection tank, and is excessively supplied into the water level detection tank. The discharged water is discharged from the overflow pipe. When excess water is supplied into the water level detection tank, water exceeding the upper end opening of the overflow pipe is discharged from the overflow pipe. Since the water level detection tank is covered with a lid and communicates with the outside via the overflow pipe, when water is discharged from the overflow pipe and air cannot pass through, the water level detection tank is filled with water discharged from the overflow pipe. Negative pressure sometimes occurred. When the inside of the water level detection tank becomes negative pressure, the water in the steam generation container flows backward to the water level detection tank, and the heating body of the heating means in the steam generation container generates heat with most of the part exposed from the water. There was a possibility that the inside of the steam generating container might be empty. The present invention prevents water from flowing back from the steam generation container into the water level detection tank by preventing the water level detection tank from becoming negative pressure when excessive water level is discharged from the overflow part. The purpose is to prevent the generation container from becoming empty.

  In order to solve the above problems, a steam generation container storing water of a predetermined water level, a heating means for heating the water in the steam generation container, a water level detection tank communicating with the lower part of the steam generation container, and a water level detection A water level sensor provided in the tank for detecting the water level in the steam generation container by detecting the water level inside the tank, and a cylindrical overflow part that discharges excess water in the water level detection tank The steam generator is provided with a water guide section that generates a circumferential water flow in the water flowing into the upper edge of the overflow section. .

  In the steam generator configured as described above, when the water in the water level detection tank flows into the overflow portion, the water in the water level detection tank flows into the overflow portion from the water guide portion at the upper edge of the overflow portion. The water flowing in from these water guide sections generates a circumferential water flow in the overflow section, and the water flowing into the overflow section falls while spirally spiraling. At this time, the water that falls in the overflow portion falls while spirally spiraling along the inner peripheral surface, so that there is no water in the central portion in the direction orthogonal to the axial direction of the overflow portion, so that air can pass through. It has become. Thereby, when the water of an excessive water level is supplied to a water level detection tank and water is discharged | emitted from an overflow part, the inside of a water level detection tank can be prevented from becoming a negative pressure. As described above, since the inside of the water level detection tank can be prevented from becoming a negative pressure, hot water heated in the steam generation container can be prevented from flowing back to the water level detection tank, and the inside of the steam generation container is empty. I was able to prevent being whispered.

  In the steam generator configured as described above, a cutout formed in the upper edge of the overflow portion is preferable as one embodiment of the water guide portion.

  In the steam generator configured as described above, it is preferable that the horizontal cross-sectional area of the overflow portion is larger in the upper portion than in the lower portion, and when this is done, the water flowing into the overflow portion from the water guide portion is spiraled. It became easier to spiral.

  In the steam generator configured as described above, a water supply unit for supplying water to a position close to one side in the longitudinal direction in the horizontal direction is provided at the top of the water level detection tank, and the bottom of the water level detection tank It is preferable to form an inclined surface in which one side in the longitudinal direction provided with a water supply part is high and the other side is low, and water injected into the water level detection tank from the water supply part is formed by the inclined surface at the bottom of the water level detection tank. The water flowing from one side of the longitudinal direction to the other side and flowing to the other side in the longitudinal direction of the bottom in the water level detection tank became a flow rising on the other side. As a result, water injected into the water level detection tank is prevented from foaming, and erroneous detection of the water level in the water level detection tank by the water level sensor can be prevented.

It is a front view of the heating cooker incorporating the steam generator of this invention. It is sectional drawing of the AA line of FIG. It is the side view which removed the side panel of FIG. 1 and made the machine room visible. It is the schematic which shows the gas path | route of a heating apparatus. It is the schematic which shows the other gas path | route of a heating apparatus. It is a perspective view of a steam generator. It is sectional drawing of the steam generation container in the position shown to the BB line of FIG. It is sectional drawing of the steam generation container in the position shown to CC line of FIG. 7, and is sectional drawing which further fractured | ruptured the center part of the perpendicular | vertical part of a heating cylinder along the axial direction. It is sectional drawing (a) of the water level detection tank in the position shown to the DD line of FIG. 6, and sectional drawing (b) of the water level detection tank in the position shown to the EE line of Fig.9 (a) It is. It is a top view (a) of a water level detection tank in the state where a lid was removed, and is a sectional view (b) of a water level detection tank in the position shown by the FF line of FIG.

  Hereinafter, an embodiment in which a steam generator according to the present invention is applied to a cooking device such as a steam convection oven will be described with reference to the accompanying drawings. As shown in FIGS. 1 to 3, the heating cooker 10 includes a cooking chamber 12 for cooking foods in a portion excluding the left side in the housing 11, and a machine room in the space on the left side of the housing 11. 13. As shown in FIG. 2, a heating tube 21 of the heating device 20 is disposed in the cooking chamber 12, and the heating tube 21 allows the combustion gas to pass through the surroundings of the heating tube 21 by passing the combustion gas. The inside of the cooking cabinet 12 is heated by exchanging heat with air.

  A fan 14 a of a fan device 14 for circulating air is rotatably attached to the left side wall of the cooking cabinet 12. The fan 14 a is a centrifugal fan such as a sirocco fan, and is attached to the inner peripheral side of the heating tube 21 on the left side wall of the cooking cabinet 12. A fan motor 14 b that rotates the fan 14 a is fixed to the machine room 13 at the center of the left side wall of the cooking chamber 12. When the fan 14a is rotated by the fan motor 14b, the air in the cooking chamber 12 is blown to the heating tube 21 and circulates in the cooking chamber 12 as hot air. A temperature sensor (not shown) is provided in the cooking cabinet 12, and this temperature sensor detects the temperature in the cooking cabinet 12.

  As shown in FIGS. 2 and 3, a heating device 20 excluding the heating tube 21 and the gas burner 22 described above is provided on the upper front side of the machine room 13. The heating device 20 heats the inside of the cooking chamber 12 with combustion gas generated by gas combustion. As shown in FIGS. 2 to 4, a mixing tube 23 is connected to the gas burner 22 provided in the large-diameter portion 21 a serving as a combustion chamber of the heating tube 21, and the mixing tube 23 is connected to an air supply tube 24 and a gas supply. A tube 26 is connected. A blower fan 25 is connected to the air supply pipe 24, and combustion air is supplied to the mixing pipe 23 through the air supply pipe 24 by driving the blower fan 25.

  As shown in FIG. 4, a city gas supply source or a propane gas supply source (not shown) is connected to the gas supply pipe 26. Gas valves 26a and 26b are interposed in the gas supply pipe 26, and fuel gas is supplied and shut off by opening and closing the gas valves 26a and 26b. A pressure equalizing valve 27 is interposed in the gas supply pipe 26 between the gas valves 26a and 26b. The pressure equalizing valve 27 adjusts the supply amount of the fuel gas in accordance with the supply pressure of the air supplied from the air supply pipe 24 connected by the pressure detection pipe 24a. Specifically, the pressure equalizing valve 27 adjusts the opening degree of the valve by a rubber diaphragm that is deformed according to the supply pressure of air supplied from the pressure detection pipe 24a, and the primary pressure is changed to the supply pressure of air. The supply amount of the fuel gas is adjusted by adjusting the pressure on the secondary side according to the pressure. A heater 28 is provided around the pressure equalizing valve 27, and the heater 28 makes the pressure equalizing valve 27 less susceptible to the influence of the ambient temperature (particularly the low ambient temperature). Specifically, the pressure equalizing valve 27 is configured to reduce the pressure on the secondary side of the pressure equalizing valve 27 because the rubber diaphragm incorporated therein is cured under the influence of the ambient temperature (for example, at a low temperature lower than 10 ° C.). There is a possibility that the flow rate of the fuel gas passing therethrough cannot be set to an appropriate flow rate without being able to achieve an appropriate set pressure. In this embodiment, the flow rate of the fuel gas passing through the pressure equalizing valve 27 is set to an appropriate flow rate so as to prevent the heater 28 from curing the rubber diaphragm of the pressure equalizing valve 27.

  As shown in FIG. 5, a differential pressure sensor 29 is provided between the gas supply pipe 26 and the pressure detection pipe 24a, and heating is performed when the pressure difference detected by the differential pressure sensor 29 is not within a predetermined range. Gas combustion by the apparatus 20 may be stopped. Further, when the pressure difference detected by the differential pressure sensor 29 is not within the predetermined range, it may be determined that an abnormality has occurred in each component constituting the heating device 20, and the abnormality may be notified by a buzzer or a display panel.

  As shown in FIGS. 2, 3 and 6, a steam generator 30 for supplying steam into the cooking chamber 12 is provided at the rear of the machine room 13. The steam generating device 30 is connected to the steam generating container 31 that stores water of a predetermined water level, the heating means 40 that heats the water in the steam generating container 31, and the lower part of the steam generating container 31. A water level detection tank 32 for detecting the water level inside, a water level sensor 35 provided in the water level detection tank 32 for detecting the water level in the steam generating container 31 by detecting the water level inside, and a water level detection tank And an overflow portion 34 having a cylindrical shape for discharging water at an excessive water level.

  As shown in FIGS. 6 and 7, the steam generation container 31 has a rectangular parallelepiped shape and stores water at a predetermined water level, and is fixed to the outside of the left side wall of the cooking chamber 12. The steam generating container 31 is provided with a heating means 40, and the heating means 40 heats water in the steam generating container 31 to generate steam. Although the heating means 40 of this embodiment heats water with the combustion gas by gas combustion, even if it is a heating body using a heater which generates heat by electric resistance, or a heater using a heater which generates heat by induction heating, Good.

  As shown in FIG. 7, the heating means 40 includes a heating cylinder 41 and a gas burner 42 as heating bodies in the steam generation container 31, and the heating cylinder 41 heats combustion gas by the gas burner 42 passing through the inside. Is a heat exchanger that heats by exchanging heat with surrounding water. The heating cylinder 41 is a cylindrical member having an L-shape when viewed from the side. The end of the horizontal portion 41 a of the heating cylinder 41 is fixed to the lower front wall of the steam generating container 31, and the vertical portion 41 b of the heating cylinder 41. Is fixed to the rear portion of the upper wall of the steam generating container 31. Five bent portions 41c are formed in the middle portion in the vertical direction of the vertical portion 41b of the heating cylinder 41 so that the diameter is slightly increased outward. The bent portion 41c suppresses distortion due to thermal expansion when the heating cylinder 41 is fixed to the steam generating container 31 by welding or the like and when the combustion gas passes, and the fixing portion between the heating cylinder 41 and the steam generating container 31 is cracked. This is to prevent the occurrence and increase the contact area with the surrounding water to increase the efficiency of heat exchange.

  As shown in FIGS. 7 and 8, an inner cylinder 43 with the upper and lower ends closed is provided concentrically inside the vertical portion 41 b of the heating cylinder 41. A pair of through holes 41d are formed in the upper part of the vertical part 41b of the heating cylinder 41 at positions opposite to each other in the circumferential direction, and the through hole of the vertical part 41b of the heating cylinder 41 is formed in the upper part of the inner cylinder 43. A pair of through holes 43a are formed at positions facing 41d. In addition, a pair of through holes 41e are formed at positions opposite to each other in the circumferential direction at the lower portion of the vertical portion 41b of the heating cylinder 41, and the vertical portion 41b of the heating cylinder 41 is formed at the lower portion of the inner cylinder 43. A pair of through holes 43b are formed at positions facing the through holes 41e. In the vertical portion 41 b of the heating cylinder 41, the upper and lower through holes 41 d and 41 e and the upper and lower through holes 43 a and 43 b of the inner cylinder 43 are connected to connect the inside of the steam generating container 31 and the inner cylinder 43. The communicating cylinder 44 is provided in a direction perpendicular to the axial direction of the vertical portion 41 b and the inner cylinder 43, and the water in the steam generating container 31 can pass through the inner cylinder 43 by the communicating cylinder 44.

  A gas burner 42 is provided in the horizontal portion 41 a of the heating cylinder 41, and the horizontal portion 41 a serves as a combustion chamber for the gas burner 42. As shown in FIG. 7, a mixing pipe 45 is connected to the gas burner 42, and an air supply pipe 46 and a gas supply pipe 48 are connected to the mixing pipe 45. A blower fan 47 is connected to the air supply pipe 46 in the same manner as the heating apparatus 20 described above, and a city gas supply source or a propane gas supply source is connected to the gas supply pipe 48 in the same manner as the heating apparatus 20 described above. . The gas supply pipe 48 is provided with gas valves 48 a and 48 b and a pressure equalizing valve 49 in the same manner as the heating device 20 described above, and the fuel gas supplied from the gas supply source is supplied from the gas supply pipe 46 by the pressure equalizing valve 49. The fuel gas supply amount is adjusted according to the supply pressure of the supplied air. The details are the same as those of the heating device 20 described above, and are therefore omitted.

  As shown in FIG. 6, the water level detection tank 32 is for detecting the water level of the steam generation container 31, and is fixed to the side surface of the steam generation container 31. As shown in FIG. 6 and FIG. 9, the water level detection tank 32 is a bottomed cylindrical container, and its upper surface opening is closed by a lid 32a. As shown in FIG. 10 (a), the water level detection tank 32 has a shape obtained by cutting away a pair of diagonal corners having a rectangular shape when viewed from above, as shown in FIGS. The bottom of the water level detection tank 32 is downward as it proceeds from one side (FIG. 9 (a), the right side of FIG. 10) to the other side (FIG. 9 (a), the left side of FIG. 10) when viewed from above. Inclined. At the bottom of the water level detection tank 32, a communication port 32b is formed on the other side in the longitudinal direction which is deeper (lower). The lower part of the water level detection tank 32 is connected to the lower part of the steam generation container 31 through a communication pipe 33 from a communication port 32b.

  At the bottom of the water level detection tank 32, a drain port 32c is formed at one corner in the longitudinal direction which is shallow (high). A partition wall portion 32d is formed at one corner in the longitudinal direction, which is the shallower side of the water level detection tank 32, so as to surround the drainage port 32c at the corner portion, and between the partition wall portion 32d and the corner portion of the water level detection tank 32. A cylindrical overflow portion 34 is constituted by the peripheral wall. The overflow part 34 is for discharging the excessive water level in the water level detection tank 32. The overflow part 34 includes a drainage cylinder part 34 a extending downward from the bottom of the water level detection tank 32, and the horizontal sectional area in the drainage cylinder part 34 a is formed smaller than the sectional area of the upper part. A drain pipe 34 b is connected to the drain cylinder 34 a, and the tip of the drain pipe 34 b is connected to a drain tank 15 that receives drainage from the cooking chamber 12. The partition wall portion 32d of the overflow portion 34 includes a first partition wall portion 32e parallel to the longitudinal direction of the water level detection tank 32 and a second partition wall portion 32f parallel to the direction orthogonal to the longitudinal direction, and the first and second partition wall portions 32e. , 32f are connected at right angles. Notches 32e1 and 32f1 are formed at the upper edges of the first and second partition walls 32e and 32f, and these notches (water guide portions) 32e and 32f are circumferentially connected to the water flowing into the overflow portion 34. The water flow is generated.

  In the water level detection tank 32, a water level sensor 35 is provided at a substantially central portion in the horizontal direction. The water level sensor 35 is formed of a float switch, and supports a float 35b movably in a vertical direction on a support column 35a extending in the vertical direction. The water level sensor 35 detects the water level in the water level detection tank 32 by detecting that the float 35b moves up and down due to the buoyancy of the water in the water level detection tank 32, and becomes the same water level as the water level in the water level detection tank 32. The water level in the steam generation container 31 is detected. The water level sensor 35 detects an upper limit water level and a lower limit water level necessary for generating steam in the steam generating container 31.

  The lid 32a of the water level detection tank 32 is provided with a water supply part (water supply port) 32g at one end in the longitudinal direction when viewed from above (the right side in FIG. 9A and FIG. 10). A water supply pipe 36 is connected to the portion 32g. A water supply valve (not shown) is provided in the water supply pipe 36, and water is supplied from the water supply pipe 36 into the water level detection tank 32 by opening the water supply valve, and the water supplied into the water level detection tank 32 is supplied. Flows into the steam generation container 31 through the communication pipe 33. As described above, the bottom of the water level detection tank 32 proceeds from one side (FIG. 9A, right side in FIG. 10) to the other side (FIG. 9A, left side in FIG. 10) when viewed from above. The water supply part 32g is provided above the bottom part where the water level detection tank 32 is high. As shown by the two-dot chain line arrow in FIG. 10, the water injected from the water supply part 32g into the water level detection tank 32 flows from one side to the other side in the longitudinal direction by the inclined surface of the bottom part of the water level detection tank 32, and the water level detection The water that has flowed to the other side in the longitudinal direction of the bottom in the tank 32 becomes a flow that rises on the other side. Thus, the water injected into the water level detection tank 32 becomes a water flow as shown by the arrow in FIG.

  As shown in FIG. 9B, the bottom surface of the lid 32a of the water level detection tank 32 is supplied with water at one end in the longitudinal direction when viewed from above (the right side in FIG. 9A and FIG. 10). A partition plate portion 32 h that divides the portion 32 g and the overflow portion 34 extends downward so that water injected from the water supply portion 32 g into the water level detection tank does not directly flow into the overflow portion 34.

  The operation of the cooking device 10 configured as described above will be described. The heating cooker 10 includes a hot air mode in which the fan device 14 and the heating device 20 are operated to cook with hot air, a steam mode in which the fan device 14 and the steam generator 30 are operated to cook with steam, a fan There are three cooking modes: a combination mode in which the device 14, the heating device 20, and the steam generating device 30 are operated to cook with hot air containing steam.

  When a cooking program in the combination mode is executed by the cooking device 10 and the heating device 20 is operated, first, the gas valves 26a and 26b are opened, and the blower fan 25 is operated. Combustion air is introduced from the supply pipe 24 into the mixing pipe 23 by the operation of the blower fan 25, and the fuel gas whose flow rate is adjusted by the pressure equalizing valve 27 according to the supply pressure of the combustion air in the supply pipe 24 is a gas. It is introduced from the supply pipe 26 into the mixing pipe 23. A mixed gas in which combustion air and fuel gas are mixed is sent from the mixing pipe 23 to the gas burner 22, and this mixed gas is burned by the gas burner 22 to become combustion gas. The combustion gas is exhausted out of the housing 11 through the heating pipe 21. At this time, the air around the heating pipe 21 is heated by exchanging heat with the combustion gas passing through the heating pipe 21, and this heated air becomes hot air by the fan 14 a of the fan device 14 and flows inside the cooking chamber 12. Circulate.

  When the steam generator 30 is operated by executing a cooking program in the combination mode with the heating cooker 10, first, the gas valves 48 a and 48 b are opened, and the blower fan 47 is operated. The combustion air is introduced from the supply pipe 46 into the mixing pipe 45 by the operation of the blower fan 47, and the fuel gas whose flow rate is adjusted by the pressure equalizing valve 49 according to the supply pressure of the combustion air in the supply pipe 46 is a gas. It is introduced from the supply pipe 48 into the mixing pipe 45. A mixed gas in which combustion air and fuel gas are mixed is sent from the mixing tube 45 to the gas burner 42, and this mixed gas is combusted by the gas burner 42 in the horizontal portion 41a of the heating cylinder 41 serving as a combustion chamber. It becomes. Combustion gas is sent from the horizontal part 41a of the heating cylinder 41 to the vertical part 41b, and when passing through the vertical part 41b, it passes between the inside of the vertical part 41b and the outside of the inner cylinder 43 and rises. 11 is exhausted outside.

  At this time, the water in the steam generation container 31 is heated by exchanging heat with the combustion gas passing through the heating cylinder 41. As shown in FIG. 8, the water outside the heating cylinder 41 in the steam generation container 31 flows into the inner cylinder 43 from the lower through hole 41 e through the communication cylinder 44 and into the lower portion of the inner cylinder 43. The raised water rises in the inner cylinder 43, passes through the upper communication cylinder 44, and flows out from the upper through hole 41 d to the outside of the heating cylinder 41 in the steam generation container 31. The water in the steam generation container 31 is heated not only at the portion that contacts the outer peripheral surface of the heating cylinder 41 but also at the portion that flows into the inner cylinder 43 and contacts the inner peripheral surface of the inner cylinder 43. Thus, since the inner cylinder 43 is provided inside the heating cylinder 41, the heat of the combustion gas can be efficiently exchanged with water, the consumption of fuel gas can be reduced, and the housing can be reduced. The temperature of the exhaust gas discharged could be lowered.

  As described above, the water in the steam generation container 31 is heated by the heat exchange with the surroundings of the heating cylinder 41 and the inner cylinder 43 to become hot water, and the hot water further becomes steam. Steam generated in the steam generation container 31 is supplied to the cooking chamber 12 by a steam outlet pipe attached to an outlet 31a formed on the upper wall of the steam generation container 31, and the supplied steam is supplied to the heating device 20, the fan device 14, and the like. It circulates in the cooking chamber 12 together with hot air. The food stored in the cooking cabinet 12 is cooked by the hot air containing the steam.

  When steam is generated by the steam generator 30, the water level in the steam generation container 31 gradually decreases due to the generation of steam, and accordingly, the water level in the water level detection tank 32 also decreases. When the water level sensor 35 detects the lower limit water level in the water level detection tank 32, the water supply valve is opened based on the control of a control device (not shown), and water is supplied from the water supply pipe 36 to the water level detection tank 32. The water supplied to the water level detection tank 32 flows into the steam generation container 31 through the communication pipe 33, and the water level detection tank 32 and the steam generation container 31 are at the same water level. When the water in the water level detection tank 32 rises by the water supplied from the water supply pipe 36 and the water level sensor 35 detects the upper limit water level in the water level detection tank 32, the water supply valve is closed based on the control of a control device (not shown). Thus, the supply of water from the water supply pipe 36 to the water level detection tank 32 is stopped. As described above, the steam generation container 31 and the water level detection tank 32 are controlled so as to have an appropriate water level based on the detection by the water level sensor 35.

  As described above, the steam generation container 31 and the water level detection tank 32 are controlled to be at an appropriate water level based on the detection of the water level sensor 35, but due to a failure of the water supply valve or a malfunction of the control of the water supply valve, The water level detection tank 32 may be supplied with excessive water level. In this case, the water in the water level detection tank 32 overflows from the overflow part 34 and is drained.

  In addition, foreign matter is prevented from entering the water level detection tank 32, and the steam discharged from the lower portion of the cooking chamber 12 rises through the drain tank 15 and the drain pipe 34 b to the overflow portion 34, and the water level detection tank 32. In order to prevent leakage from the water into the machine room 13, the water level detection tank 32 is closed in a substantially sealed state by a lid 32a. On the other hand, the steam generating container 31 has a steam outlet 31a formed in the upper wall for supplying steam into the cooking chamber 12, and the steam generating container 31 is in a state in which outside air can be easily introduced. Yes.

  In the steam generator 30 of the present invention, as shown in FIG. 10A, notches 32e1 and 32f1 are formed as water conduits on the upper edge of the partition wall 32d constituting the overflow part 34. If the notch is not formed on the upper edge of the partition wall 32d as in the prior art, the water flowing in from the upper edge of the partition wall 32d flows down from the entire circumferential direction of the partition wall 32d in the axial direction at a time and overflows. There was a possibility that air could not pass through the water in the section 34 due to the water flowing down, and the inside of the water level detection tank 32 became negative pressure. On the other hand, in the steam generator 30 of the present invention, when the water in the water level detection tank 32 flows into the overflow part 34, the water in the water level detection tank 32 is notched 32e1, 32f1 at the upper edge of the partition wall part 32d. Into the overflow part 34. The water flowing from the notches 32e1 and 32f1 generates a circumferential water flow in the overflow portion 34 as shown by the solid line arrow in FIG. 10A, and the water flowing into the overflow portion 34 is spiral. It falls while swirling in a shape. At this time, since the water falling on the overflow portion 34 falls while spirally spiraling along the inner peripheral surface, there is no water in the central portion in the direction orthogonal to the axial direction of the overflow portion 34, so that the air It is possible to pass. Thereby, when the water of the excessive water level is supplied to the water level detection tank 32 and the water is discharged from the overflow part 34, the inside of the water level detection tank 32 can be prevented from becoming a negative pressure. In this manner, since the inside of the water level detection tank 32 can be prevented from becoming a negative pressure, the hot water heated in the steam generation container 31 can be prevented from flowing back to the water level detection tank 32, and the steam generation container It was possible to prevent the inside of 31 from becoming empty.

  The overflow part 34 is composed of an internal part of the water level detection tank 32 and a part of the drain cylinder 34a below the overflow part 34. The horizontal cross-sectional area of the overflow part 34 is higher than that of the drain cylinder 34a. The inner part of the detection tank 32 was enlarged. Thereby, the water that has flowed into the overflow portion 34 from the notches 32e1 and 32f1 is likely to flow down while spiraling in a wide area.

  Further, the lid 32 a provided on the upper part of the water level detection tank 32 is provided with a water supply part 32 g for supplying water to a position close to one side in the longitudinal direction in the horizontal direction, and the bottom of the water level detection tank 32. An inclined surface having a water supply portion 32g provided on one side in the longitudinal direction and having a lower side on the other side was formed. The water injected into the water level detection tank 32 from the water supply part 32g flows from one side in the longitudinal direction to the other by the inclined surface at the bottom of the water level detection tank 32, and flows to the other side in the longitudinal direction at the bottom in the water level detection tank 32. Became a rising flow on the other side. As a result, the water injected into the water level detection tank 32 becomes a water flow as shown by an arrow in FIG. 10 so as not to foam, and an erroneous detection of the water level in the water level detection tank 32 by the water level sensor 35 occurs. I was able to prevent it.

  In addition, although the two notches 32e1 and 32f1 are formed on the upper edge of the overflow portion 34 as a water guide portion for generating a circumferential water flow in the water flowing into the inside, the present invention is not limited to this. The number of notches may be one or three or more. When there are a plurality of notches, it is necessary to consider that the water flows introduced into the overflow portion 34 from the notches do not cancel each other. Further, at the upper edge of the overflow portion 34, one or more through-hole portions are formed on the upper end portion (upper edge) of the partition wall portion 32d instead of the notch portion as a water guide portion for generating a circumferential water flow in the water flowing into the inside. May be formed.

  Further, the overflow part 34 forms a cylindrical region by the peripheral wall of the water level detection tank 32 and the partition part 32d provided so as to face the peripheral wall, but the present invention is not limited to this. The overflow portion 34 may be one using a cylindrical material provided in the water level detection tank 32, and the same effect as described above can be obtained also in this way.

 DESCRIPTION OF SYMBOLS 30 ... Steam generator, 31 ... Steam generation container, 32 ... Water level detection tank, 32e1, 32f1 water conveyance part, Notch part, 32g ... Water supply part, 34 ... Overflow part, 35 ... Water level sensor, 40 ... Heating means, 43 ... Circulation guide, 44 ... lead-out part, 45 ... shielding plate, 46 ... drainage part.

Claims (4)

A steam generating container storing water of a predetermined water level;
Heating means for heating water in the steam generation container;
A water level detection tank in communication with the lower part of the steam generation container;
A water level sensor provided in the water level detection tank for detecting the water level in the steam generating container by detecting an internal water level;
A steam generator comprising a cylindrical overflow part for discharging water at an excessive water level in the water level detection tank,
The steam generator according to claim 1, wherein a water guide portion is provided at an upper edge of the overflow portion to generate a circumferential water flow in the water flowing into the overflow portion. The steam generator according to claim 1,
The steam generation device according to claim 1, wherein the water guide portion is a notch formed in an upper edge of the overflow portion. The steam generator according to claim 1 or 2,
The steam generator according to claim 1, wherein the horizontal cross-sectional area of the overflow portion is larger in the upper part than in the lower part. In the steam generator according to any one of claims 1 to 3,
The water level detection tank is provided with a water supply unit for supplying water to a position close to one side in the longitudinal direction in the horizontal direction, and the water level detection tank is provided with the water supply unit at the bottom. A steam generator characterized in that an inclined surface is formed in which one side of the direction is high and the other side is low.

Images