JPS6237284B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high temperature air mixed steam generator for modifying the properties of wet saturated steam generated in a boiler.

The steam generated from a small standard boiler that is not equipped with a steam heater is wet saturated steam with poor dryness. Modern steam boilers have become smaller, and the amount of water held in the can is small, making carry-over more likely to occur during high loads when the most heat is needed. to
It is 0.9 to 0.7%, and as a result of using wet steam with a large amount of condensate (moisture) and a small amount of latent heat required during heat exchange, a large heat loss occurs.

The amount of heat retained by such wet saturated steam depends on its dryness (x). The dryness (x) here indicates the weight ratio of steam (gas) in wet steam. For example, the heat exchange heat transfer surface of a heating material appliance such as a heater or a steam iron is formed by a limited supply steam holding volume and a heat transfer area, so that it is difficult to prevent moisture from entering such heating equipment. When a large amount of moist saturated steam is supplied, the steam loses its latent heat and begins to condense inside the heating equipment, and the dryness (x) inside the equipment is 0.9~
It is 0.7.

In other words, when the same amount of steam is supplied, the proportion of steam in the internal volume of the device decreases, and the latent heat that only steam can hold decreases, resulting in a significant decrease in heat absorption and utilization efficiency. . In order to compensate for this, there is no choice but to supply a larger amount of wet steam, which has the drawback of increasing the amount of steam used by the boiler, which is directly linked to fuel loss.

As described above, in a heat transfer surface having a fixed volume, the volume ratio occupied by steam (void ratio) has a decisive influence on the heat consumption amount and heat absorption efficiency of the heating device.

On the other hand, the moisture generated from the wet saturated steam forms a thick drain layer on the heat exchange heat transfer surface of the heating equipment.

Since this drain layer has extremely poor thermal conductivity, it has the drawback of significantly reducing the heat absorption and utilization efficiency of the equipment.

This invention is intended to solve the above-mentioned drawbacks.The purpose of this invention is to utilize the exhaust heat of the boiler in a heating box attached to the boiler exhaust pipe, in which steam used in the boiler and pressurized air are separately supplied. By heating the resulting superheated steam heated to about 200° and mixing it with high-temperature heated air in a mixer, the properties of the wet saturated steam are modified, and the properties of the wet saturated steam are improved. To provide a high-temperature air-mixed steam generator that can supply high-calorie dry air-mixed superheated steam to each heating device and can be applied to all kinds of steam boilers without modification.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the accompanying drawings.

In the figure, a steam boiler body a is mainly composed of an insulating exterior body 1, an internal firebox 2, and upper drums 3, 3 disposed above the firebox 2.

Inside the firebox 2, a plurality of water pipes 4 connected to the lower part of the upper drum 3 at the upper part are arranged. The lower part of the upper drum 3 and the Hotwell tank 5 installed outside the machine are connected by a water supply pipe 7 via a boiler feed pump 6, and the hot water in the Hotwell tank 5 is pumped into the upper drum 3 by the boiler feed pump 6. Water is supplied and stored up to a predetermined water level. An oil burner 8 is placed facing one end of the lower part of the exterior body 1, and the inside of the fire chamber is heated by combustion to about 1200°C by the combustion of the oil burner 8.

During the process in which the high-temperature combustion gas flows in the direction of the arrow through the fire chamber baffle plate 9 appropriately installed in the fire chamber 2, the water in the water pipe 4 and the canned water in the upper drum 3 are heated to a high temperature and continuously flow. The canned water in the upper drum 3 is heated and evaporated, and the canned water in the upper drum 3 is heated and evaporated.
A predetermined selected pressure (6 to 7 Kg/m ² ) is achieved within 0.
The saturated steam temperature in this case is 169.6°C.

The upper part of the steam chamber 10 is connected to a main steam pipe 11, and the main steam pipe 11 is connected to a steam supply circuit 12.

An exhaust gas supply port 16 of a heating box 15 made of a heat insulating material is arranged to match the opening 14 of an exhaust pipe 13 extending from the upper part of the exterior body 1 of the steam boiler a. Exhaust gas outlet 17 is located above the heating box 15.
A plurality of steam heating capillary tubes 19 and air heating capillary tubes 20 are respectively meandered in a meandering manner to increase the heat receiving area inside the heating box, which is opened and baffle plates 18 are appropriately arranged. One end of this steam heating pipe 19 is connected to the end of the steam supply circuit 12. In order to adjust the pressure and amount of wet steam generated in the steam chamber 10 of the upper drum, the main steam pipe 11 and the steam supply circuit 12 are provided with a main steam valve 21, a steam pressure regulating valve 22, and a steam pressure regulating valve in order of the steam flow direction. A total of 23 and an inlet check valve 24 are installed in place.

On the other hand, one end of the air heating tube 20 is connected to an air pressure feeding circuit 25, and the other end of this air pressure feeding circuit 25 is connected to an air pressure feeding device 4 such as a compressor.
3 is installed. An air pressure regulating valve 26, a pressurized air inlet pressure gauge 27, and a pressurized air inlet check valve 28 are arranged in the air flow direction in the order of the air flow direction to adjust the flow rate and pressure of the air to be supplied. The air source pressure in the operating pressure range of 6 to 7 kg/ ^m2 of the compressor 43 is constantly controlled by the air pressure regulating valve 26.
The air is pumped at a constant pressure of 4.2Kg/ ^m2 . The outlet sides of the steam heating pipe 19 and the air heating pipe 20 are connected to heating steam pressure feeding circuits 29, respectively.
and a suction mixer 31 via a heated air pumping circuit 30.

The heating steam pressure feeding circuit 29 is constructed as short as possible as shown in the figure, and is equipped with an inlet check valve 32, a pressure gauge 33, and a thermometer 34 in the steam flow direction, and the suction mixer 3
The amount of steam, steam pressure and steam temperature supplied to the heating air pump 1 can be adjusted, and the heating air pressure feeding circuit 30 includes a heating air outlet pressure gauge 35, a heating air outlet thermometer 36, a heating air outlet thermometer 36, and a heating air outlet pressure gauge 36 in order of the air flow direction. An air outlet check valve 37, an auxiliary heated air release adjustment valve 38, an inlet pressure gauge 39, an inlet thermometer 40, and an inlet check valve 41 are installed, respectively, to ensure smooth supply of heated air and adjust the temperature and pressure of the air appropriately. can be adjusted to

The above-mentioned auxiliary heating air release regulating valve 38 is connected to the heating air pressure feeding circuit 30 when steam is not used much.
This is provided in order to prevent the air temperature from decreasing due to a decrease in the flow rate of the air in the heated air pumping circuit 30, by opening the air release regulating valve 38 and releasing a small amount of heated air into the atmosphere. By improving the flow, it is possible to maintain the temperature of the pumped heating air at the location at all times at 200° C. without lowering it.

In the mixer 31, high-temperature heating air and superheated steam are mixed, and the mixed superheated steam is sent through a supply pipe 42 to heating devices (not shown) such as steam irons or heaters disposed at various locations.

While supplying superheated steam at 158°C at a constant pressure of 5 kg/m ² through the steam pressure regulating valve 22, high-temperature heated air at a temperature of 170 to 200°C at a lower pressure of 4.2 kg/m ² is sucked into the mixer. 31 to mix superheated steam and high-temperature heating air. The reason why the air pressure is set lower than the superheated steam pressure is because if the mixing inlet air pressure is higher than the steam supply pressure, the heated air will overcome the steam and mix in more high-temperature heated air than necessary, which will not produce the desired effect. be.

In order to avoid the above problems, if the mixing inlet air pressure is lower than the supply steam pressure, it will be easier to obtain mixed steam with the optimum void ratio for the heating equipment used, such as a steam iron or heater, and the discharge drain The temperature can be adjusted while controlling the drain temperature so that the pressure is as low as possible. At this time, the pressure of the heated air is controlled by the heated air outlet check valve 3.
Up to 7, it is 4.2Kg/ ^m2 .

In the suction mixer 31, two gases, namely superheated steam and high-temperature heating air, are mixed at the same temperature and pressure, so the kinetic energy (e=m ₀ ^{2 )} of both gases is /2g) are always equal, and each gas does not transfer external work or heat when it expands, so it conserves its kinetic energy, and even when different gases are mixed, they collide with each other to store kinetic energy. Since it is evenly distributed, even if the weight of the molecules is different, the above kinetic energy e = m
The value of ₀ ² /2g will be conserved for any type (Dalton's law). That is, according to the present invention, the operating temperature of the mixed steam in a heating device such as a steam iron is equal to the temperature at the time of mixing.

Also, the superheated steam pressure (5
Kg/m ² ) and lower heating air pressure (4.2
Kg/m ² ) are suction-mixed, the air pressure on the suction mixer 31 side in the air pressure feeding circuit 30 becomes the same pressure as the superheated steam pressure (5 Kg/m ² ), as determined by the inlet pressure gauge 39. This has also been confirmed. Therefore, during heat exchange within the heating device, latent heat is removed from the steam component of the mixed steam, and the amount of heat (sensible heat) held by the saturated water (drain water) remains.

High-temperature heated air has the property of adsorbing more moisture in the form of bubbles due to the temperature and heat it possesses, and the heat content (sensible heat) of saturated water is absorbed by the heated air. This effectively promotes heat absorption up to the heat absorption usage range of heating equipment.
It is clear from the discharge state of the steam drain, for example, that heat exchange is efficiently achieved within the heating device when mixed steam is supplied. That is, supply pressure Pw = 5Kg/m ² Supply steam amount (per hour) 1100Kg/H Under the above conditions, at the superizer outlet temperature
When only superheated steam at 200℃ is supplied to the supply pipe 42, a back pressure of 2.5Kg/ ^m2 is generated at the steam drain pressure gauge 44, and the temperature of the steam drain discharged is 138℃ according to the steam drain thermometer. When this steam drain was supplied untreated to the Hotwell tank 5, the temperature inside the tank rose to 98°C, and a self-steam phenomenon occurred. On the other hand, when the mixed steam of the present invention was supplied to the supply pipe 42 under the same conditions as above, the steam drain pressure was 0 kg/m and the steam drain temperature was 94°C.

When this discharged steam drain was discharged untreated into the Hotwell tank 5 in the same manner as described above, the temperature inside the Hotwell tank was 85°C.

It has been found that when the mixed superheated steam is supplied as described above, sufficient heat exchange is achieved within the heating equipment, and the absorption efficiency of the heating equipment can be maintained at a high level by the mixed steam itself. Furthermore, since steam drain is recovered at a temperature below 100°C, heat loss during drain recovery can be minimized.

Also, if only heated air is sent to the supply piping,
Although the temperature of high-temperature air shows a rapid tendency to decrease before it reaches the heating equipment, the temperature of the high-temperature air can hardly be lowered by supplying it to the heating equipment in the form of a mixed gas of moist saturated steam and heating air. do not have.

As described above, this invention installs an insulating heating box having an exhaust gas supply port on one side and an exhaust gas discharge port on the other end above the exhaust port of a steam boiler,
In the air heating chamber provided inside this heat insulating heating box, a steam heating path with a large heat receiving area and an air heating path are arranged separately, and one end of the steam heating path on the inlet side is connected to the main steam of the boiler. one end of the air heating path on the inlet side communicates with the air pumping device, and the other end of the heating steam pressure feeding pipe connected to the outlet side end of the steam heating path and the outlet of the heating path. The other end of the heating air pressure feed pipe connected to the side end is installed in a mixer, and the high temperature steam and high temperature air are mixed in the mixer, so that the wet saturated steam generated in the boiler is reformed into a higher calorie dry mixed steam that can be supplied to each heating device, the mixed steam being supplemented with hot heated air in an amount proportional to the wetness of the wet saturated steam; Increasing the proportion of gas in the generated steam, that is, achieving the same effect as increasing the dryness of the generated steam outside the boiler body regardless of the boiler function, and at the same time greatly accelerating the steam flow rate and increasing the dryness of the generated steam outside the boiler body regardless of the boiler function. In addition, this mixed steam increases the volume ratio (void ratio) occupied by gas (steam and high-temperature air) in the heat transfer surface of the heating equipment, and reduces the amount of saturated moisture ( It is possible to significantly reduce the amount of water (drainage) and provide a larger amount of heat to the heat transfer surface of the heating device. At this time, the formation of a drain layer on the heat transfer facepiece can be minimized, which greatly improves the heat absorption and effective utilization efficiency of the heating equipment, resulting in less heat consumption and a significant reduction in heating costs. Moreover, the steam drain of 100℃ or less can be discharged from the heating equipment that is supplied with mixed steam and heat exchanged, and it can be installed above the exhaust port of the boiler, so there is no need to modify the existing steam boiler. It can be used inexpensively in any steam boiler regardless of the model, and since an air heating device outside the steam boiler is attached, the heat receiving area of the air heating path inside the outer box can be arbitrarily enlarged, and it can be used more easily than inside the furnace. Since low-temperature waste heat is used, the air heating path can reduce damage caused by heat.
Therefore, the durability of the high temperature air mixed steam generator itself can be improved.

Furthermore, since waste heat is used, there is no need for any extra expense to obtain high-temperature mixed steam. In addition, before supplying mixed steam at the start of operation, only high-temperature heated air is sent under pressure to the supply piping to discharge residual condensate in the piping and heating equipment, thereby reducing heat loss at the time of steam startup supply. It has excellent effects such as being able to completely eliminate the causes of reduction or water hammer.

[Brief explanation of the drawing]

The drawings show embodiments of the invention.
The figure is a sectional view of the device in use. a... Steam boiler, 11... Main steam pipe, 15
...Insulating heating box, 16...Exhaust gas supply port, 17
...Exhaust gas outlet, 19...Steam heating pipe, 20
...Air heating pipe, 29...Heating steam pressure pipe, 3
0... Heated air pressure feed pipe, 31... Suction mixer,
38...Auxiliary heating air release adjustment valve, 43...Air pressure feeding device.

Claims (1)

[Claims] 1. A heat insulating heating box 15 having an exhaust gas supply port 16 on one side and an exhaust gas discharge port 17 on the other side is installed above the exhaust port 13 of the steam boiler a, A steam heating path 19 with a large heat receiving area and an air heating path 20 are separately arranged in an air heating chamber provided inside the heating box 15, and one end of the steam heating path 19 on the inlet side is connected to the boiler. In addition to communicating with the main steam pipe 11, one end of the air heating path 20 on the inlet side is connected to the air pressure feeding device 43, and the other end of the heating steam pressure feeding pipe 29 connected to the outlet side of the steam heating path 19. The other end of the heated air pressure feed pipe 30 connected to the outlet side of the heating path is installed in a mixer 31, and the high temperature steam and high temperature air are mixed in the mixer 31. High temperature air mixed steam generator. 2 The steam heating path 19 and the air heating path 20 are
The high-temperature air mixed steam generator according to claim 1, characterized in that it is a plurality of meandering thin tubes. 3. The high temperature air mixed steam generator according to claim 1, wherein the heated air pressure feed pipe 30 is provided with an auxiliary heated air release regulating valve 38 that can be opened and closed as appropriate.