JP2000283676A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make movement of medium on each of trays smooth even if high temperature gas is contaminated with adhering substances. SOLUTION: In a heat exchanger 1 for an incineration ash melting furnace heat is absorbed from high temperature gas 10 by medium 6 on a tray 23 at an upper high temperature chamber 2, the medium 6 is introduced into a lower low temperature chamber 2, heat is given to low temperature gas 11 on the tray 33, and then the medium 6 is returned back to the high temperature chamber 2. A dispersion plate 7 is placed from the high temperature chamber 2 to a low temperature chamber 3, the dispersion plate 7 is vibrated and at the same time a clearance in respect to the communicating pipe 4 is changed. An amount of the moving medium 6 passing through the communicating pipe 4 is adjusted by the vibration and the variable clearance, and an amount of medium in both chambers 2, 3 is made most suitable one. Trays 23, 33 are vibrated, the upper tray 23 is inclined and so even if a large amount of adhering substances is present, motion of the medium 6 on the trays 23, 33 is made smooth. With such an arrangement as above, circulation of the medium 6 is carried out smoothly and the most suitable heat exchanging action is performed under combination with adjustment of the aforesaid amount of medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger for removing heat from an exhaust gas (high-temperature gas) from an incineration ash melting furnace by a medium and exchanging heat for giving heat to the low-temperature gas.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 54-139160 is an example of this type of conventional heat exchanger. In this case, as shown in FIG. 8, the heat exchanger 1 is divided into an upper high-temperature chamber 2 and a lower low-temperature chamber 3, and the high-temperature chamber 2 has a high-temperature gas inlet 21 at its lower part and a high-temperature gas outlet at its upper part. 22 has a plurality of trays (perforated plates) 23 therein. The low-temperature chamber 3 has a low-temperature gas (air) inlet 31 at the lower part, a low-temperature gas outlet 32 at the upper part, and a plurality of trays 33 inside. The trays 23 and 33 have openings 2 at alternate positions at each end so that the medium 6 flows down meandering through each step.
3a and 33a are formed.

In order to circulate the medium 6, the medium inlet 24 at the upper part of the high temperature chamber 2, the communication pipe 4 connecting the high temperature chamber 2 and the low temperature chamber 3, and the medium outlet 34 at the lower part of the low temperature chamber 3 are provided.
And a transfer means 5 provided outside the two chambers 2 and 3.

In the heat exchanger 1, the high-temperature gas 10 is introduced from the high-temperature gas inlet 21 and discharged from the high-temperature gas outlet 22, and the low-temperature gas 11 is introduced from the low-temperature gas inlet 31 and discharged from the low-temperature gas outlet 32. .

[0005] The medium 6 introduced into the high-temperature chamber 2 from the medium inlet 24 is first placed on a tray 23 in the high-temperature chamber 2.
When fluidized by the hot gas 10, the hot gas 10
Absorb heat. High temperature gas cooled by absorbing heat 1
0 is discharged from the hot gas outlet 22.

Next, the medium 6 having absorbed the heat flows down the trays 23 of the respective stages, and then passes through the communication pipe 4 to form the lower low-temperature chamber 3.
Descends. At this time, the inside of the communication pipe 4
In order to prevent 11 from leaking into another room 2 or 3,
The medium 6 is maintained in a filled state.

In the low temperature chamber 3, the medium 6
On 3, heat is applied to the cold gas 11 when it is caused to flow by the cold gas 11. The low-temperature gas 11 that has been heated and has a higher temperature is discharged from the low-temperature gas outlet 32. On the other hand, the heated medium 6 is transferred from the medium outlet 34 provided at the lower part of the low temperature chamber 3 to the transfer means 5 and then lifted by the transfer means 5 to the medium inlet 24 provided at the upper part of the high temperature chamber 2. Then, it is put into the high temperature chamber 2 again.

[0008] In recent years, waste disposal has become a major social problem. The waste is roughly divided into general waste represented by municipal waste and industrial waste.
Combustible materials such as kitchen waste, paper, wood, fiber, food waste, rubber and waste plastics are incinerated. The incinerated ash consists of main ash, which is burned, and fly ash, which is soaked.
SiO ₂ , Al ₂ O ₃ , CaO, metal oxide, NaC
l, KCl and the like, and a little AlCl ₃ having adhesiveness. Fly ash is a component similar to the main ash, but low-boiling metals react with chlorine compounds to form ZnCl ₂ , PbC
l ₂ , AlCl ₃ , CdCl ₂ , HgCl ₂ , CaCl
_It contains a lot of metal chlorides with adhesive properties such as ₂ . Further, if the hydrogen chloride in the incinerated ash is captured by Ca (OH) ₂ or the like, the amount of highly adherent CaCl ₂ will increase.

Further, the incineration ash is melted and solidified for volume reduction and safety, and the furnace temperature of the melting furnace for melting the incineration ash is set higher than that of incinerators such as municipal solid waste. For this reason, even in this melting furnace, the low-boiling point metal and the like react with the chlorine compound, and the above-mentioned metal chloride (chloride) having the adhesive property is further generated. At this time, most of the incinerated ash is melted and discharged as molten slag, but the adhered chloride is discharged as dust together with the exhaust gas.

The dust discharged from the melting furnace is referred to as fly ash, and contains a large amount of highly adherent chloride.

[0011]

In the heat exchanger 1 described above, when the combustion exhaust gas from the above-described incineration ash melting furnace is used as the high-temperature gas 10 (see the embodiment), the high-temperature gas 10 in the exhaust gas is used. The dust contains a large amount of the above-mentioned adhering substance, and the adhering substance gradually adheres to the surface of the medium 6 and the trays 23 and 33 as the heat exchanger 1 operates.

Conventionally, as shown in FIG. 8, the trays 23 and 33 are provided horizontally, and while the medium 6 is caused to flow by the gas 10 blown up from the holes, the tip openings 23 and 33 are provided.
a, 33a. That is, tray 2
Since the reference numerals 3 and 33 are horizontal, the movement of the medium 6 forward (front end side) is not smoothly performed. For this reason, the medium 6 easily adheres to the upper surfaces of the trays 23 and 33 by the adhesive substance,
In many cases, smooth circulation of the medium 6 is hindered, and if it is prevented, efficient heat exchange cannot be performed. Further, since the amount of circulation is reduced, the medium 6 to be filled in the communication pipe 4 is
And the gas 10 and 11 may flow into the other chamber 2 or 3, and the heat exchanger 1 may not be operated. In such a state, the operation of the heat exchanger 1 must be stopped and the medium 6 attached to the upper surfaces of the trays 23 and 33 must be removed.

In some cases, the trays 23 and 33 can be removed from outside the apparatus.
Since the high-temperature gas 10 of about 00 ° C. flows, the tray 23
Cleaning is not easy. On the other hand, if the trays 23 and 33 cannot be removed from the outside of the apparatus, the work will be performed inside the apparatus, and the problem will increase.

[0014] It is an object of the present invention to smoothly move the medium on a tray even if an adhering substance is mixed in the high-temperature gas.

[0015]

According to the present invention, a tray in a heat exchange chamber is tilted downward or vibrated so that an adhesive substance adheres to a medium on the tray. Even if the medium becomes difficult to move, the medium is forcibly moved by its own weight or vibration. If the movement is smooth, the circulation will be smooth.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION As one embodiment of the present invention, a heat exchange chamber (high-temperature chamber) through which a high-temperature gas as exhaust gas from an incineration ash melting furnace flows, and a heat-exchange chamber (low-temperature gas) through which a low-temperature gas flows (lower). Trays are provided in a plurality of stages in each of the two heat exchange chambers, and the medium is sequentially dropped onto each of the trays and circulated between the two heat exchange chambers. In the heat exchanger in which the medium absorbs heat from the gas and the low-temperature gas absorbs heat from the medium in the lower heat exchange chamber, each tray of at least one of the heat exchange chambers may be inclined downward, A configuration in which vibration means is attached to the tray may be adopted.

If the tray is inclined, the medium also descends according to the inclination, and the circulation is smoother than in the horizontal state, and if the tray vibrates, the movement of the medium is also smooth. As a result, even if the adhesive substance adheres to the medium or the like, the medium is smoothly circulated.

The inclination and vibration action of this tray can be used in combination, and which tray of the upper heat exchange chamber or the lower heat exchange chamber should be tilted downward, provided with vibration means, or used in combination with an experiment. It may be appropriately determined according to the degree of adhesion of the medium in actual operation, and is preferably used for each tray in the upper heat exchange chamber, and more preferably for each tray in both chambers.

The inclination, amplitude, vibration time, vibration interval, and vibration intensity of the tray are also appropriately selected in accordance with the degree of adhesion of the deposits, and all the trays may be the same. The temperature may be different depending on the temperature. For example, in the case of combustion exhaust gas from a melting furnace, 700
The vicinity of ° C causes the most intense adhesion phenomenon, and the tray that comes into contact with the exhaust gas at that temperature has a steep inclination, a large vibration width, and the like as compared with other trays.

The tray is preferably one through which gas passes, such as a perforated plate, a slit plate, or a wire mesh, but may be a flat plate if there is no problem.

[0021]

1 to 7 show one embodiment. First, FIG.
FIG. 1 schematically shows a mode in which the exhaust gas (combustion gas) of the incineration ash melting furnace 51 is subjected to heat exchange as a high-temperature gas.
Is composed of a combustion section 52 and a molten pool section 53 below the combustion section 52, and an air pipe 54 is provided above the combustion section 52.
An inlet 55 and a main burner 56 for the incineration ash a of combustibles such as kitchen garbage are attached to the air pipe 54, and an ignition burner 57 is provided above the combustion section 52. Weld pool 53
Is provided with an outlet 58 for the melt and an outlet 59 for the combustion exhaust gas, and a heating burner 60 for heating the melt b is provided near the melt outlet 58.

Then, the incineration ash a and the air 11 heated in the low temperature chamber (preheating air chamber) 3 of the heat exchanger 1 are supplied to the main burner 56.
The incineration ash “a” is melted by being heated in the combustion section 52 and burned in the combustion section 52. This melt b
Falls into the molten pool 53 and is discharged from the outlet 58 by overflow. Further, the combustion gas (high-temperature gas) 10 generated in the combustion section 52 heats the melt b when moving from the combustion section 52 to the molten pool section 53, is discharged from the outlet 59, and is discharged from the outlet 59 to the high-temperature gas inlet 21 of the heat exchanger 1. Higher temperature chamber (exhaust gas chamber) 2
Will be introduced.

FIGS. 2 to 7 show details of the heat exchanger 1. The heat exchanger 1 has an upper high-temperature chamber 2 and a lower low-temperature chamber 3
It is divided into. The high-temperature chamber 2 has a high-temperature gas inlet 21 at its lower part, a high-temperature gas outlet 22 at its upper part, and a plurality of trays 23 inside. The tray 23 is provided by a perforated plate at an angle and is vibrated by the vibration means 12.

The low-temperature chamber 3 has a low-temperature gas (air)
It has an inlet 31, a low-temperature gas outlet 32 at the top, and a plurality of trays 33 inside. The tray 33 is also a perforated plate, is disposed horizontally, and is vibrated by the vibration means 12.

A medium inlet 24 for charging the medium 6 is provided in the upper part of the high temperature chamber 2 and a medium outlet 34 for discharging the medium 6 is provided in the lower part of the low temperature chamber 3. They are connected by a transfer means 5 for transferring. The high-temperature chamber 2 and the low-temperature chamber 3 communicate with each other through a communication pipe 4, and a dispersion member (dispersion plate) 7 for dispersing the medium 6 is provided below the communication pipe 4. The medium 6 is, for example, a sphere having a diameter of 1 to 3 mm and made of ceramic such as alumina.

As shown in FIG. 3, the dispersion member 7 is mounted on a holding member 20.
Is supported by the adjusting means 9 in such a manner as to freely ascend and descend to a rod 25 suspended from the lower end of the communication pipe 4. Also,
The dispersing member 7 has an air pipe 13 penetrating the central part thereof, and a ring 15 welded to the lower surface of the dispersing member 7 outside the air pipe 13.

The holding member 20 includes a cylindrical portion 14, a flange 16 provided at a lower end thereof, arms 16a radially provided around the flange 16 at equal intervals, and a tip of the arm 16a. The rod 25 penetrates the pipe 17, and the holding member 20 (dispersion member 7) moves up and down using the rod 25 as a guide. Although the dispersing member 7 is shown as a disk, the dispersing member 7 may have a shape such as an upward conical shape in consideration of the drop of the medium 6.

The dispersing member 7 is provided with a vibrating means 8, and the transmission rod 35 urges the ring 15 welded to the lower surface of the dispersing member 7 to vibrate. The vibration causes the dispersing member 7 to vibrate. If the dispersion member 7 does not move up and down, the transmission rod 35 may be screwed into the ring 15. 9
Is an adjusting means composed of a shaft 37 rotated by a driving device (not shown) and an eccentric disk 38 fixed to the end thereof. The eccentric disk 38 is engaged with the flange 16 of the holding member 20. The rotation of the eccentric disk 38 raises and lowers the holding member 20, and adjusts the gap between the dispersion member 7 and the lower surface (opening) of the communication pipe 4. The shaft 37 can also be rotated manually. 39
Is an inspection port having an observation window 40, and 41 is a television camera provided outside the observation window and observing the passage state of the medium 6.

As shown in FIGS. 4 and 5, the tray 23 of the high-temperature chamber 2 is made of a perforated plate 4 having a large number of holes 42a.
2 and a flange 43 provided at one end thereof. A vibrator 44 serving as the vibrating means 12 is fixed to the flange 43, and is inserted through an insertion port 45 formed obliquely in the steel shell 18. Inserted. The perforated plate 42 is rectangular and covers most of the high temperature chamber 2 having a circular cross section. Notches are formed in the refractory 19 made of refractory brick so that the porous plate 42 can be inserted.

As shown in FIGS. 6 and 7, the tray 33 of the low-temperature chamber 3 includes a perforated plate 4 having a large number of holes 46a.
6 and a flange 43 provided at one end thereof. A vibrator 44 is fixed to the flange 43 and is inserted through an insertion hole 45 formed perpendicularly to the steel shell 18. The perforated plate 46 is U-shaped and completely closes the cross section of the low temperature chamber 3 having a circular cross section as shown in FIG. Notches are formed in the refractory 19 so that the perforated plate 46 can be inserted.

This embodiment has the above configuration.
To explain the operation, the high-temperature gas 10 (about 900 ° C.) from the melting furnace 51 is introduced from the high-temperature gas inlet 21 and discharged from the high-temperature gas outlet 22 (about 500 ° C.). The gas is introduced from the inlet 31 and discharged from the low-temperature gas outlet 32 (about 400 ° C.).

The medium 6 introduced into the high-temperature chamber 2 from the medium inlet 24 is supplied to the high-temperature gas 10 on a tray 23 in the high-temperature chamber 2.
As the tray 23 is inclined, it gradually descends and falls from the end of the tray 23 and the hole 42a to the next tray 23.

In this process, the heat of the high-temperature gas 10 is absorbed by the medium 6, and the adhesive substance in the high-temperature gas 10 adheres to the medium 6. Therefore, the medium 6
The medium 6 adheres to the surface of the tray 23 or adheres to the surface of the tray 23. However, since the tray 23 is obliquely inclined and the high-temperature gas 10 is ejected from a number of holes 42a provided in the tray 23, 23, and smoothly fall onto the next tray 23. The vibration means 12
Is applied constantly or appropriately to prevent the medium 6 from adhering and smooth the movement.

In this manner, the medium 6 absorbs more heat than the high-temperature gas 10 on the plurality of trays 23 and when descending the plurality of trays 23. The high-temperature gas 10 that has absorbed the heat is discharged from the high-temperature gas outlet 22, and is discharged into the atmosphere through an exhaust gas treatment facility such as a bag filter.

The medium 6 having absorbed heat in the high-temperature chamber 2 falls into the cone 2a at the bottom of the high-temperature chamber 2 and then moves to the low-temperature chamber 3 while keeping the communication pipe 4 provided at the center thereof in a filled state. I do. The medium 6 discharged from the communication pipe 4 once falls on the dispersion member 7, and is then uniformly dispersed and falls in the low-temperature chamber 3.

At this time, even if the mediums 6 adhere to each other and form a large lump, if the vibration member 8 applies vibration to the dispersion member 7, the lumped medium 6 is smoothly dispersed while being dispersed. It falls from the dispersion member 7. Also, by increasing the gap between the dispersion member 7 and the lower surface of the communication pipe 4 by the adjusting means 9, the lump can be smoothly dropped.

The air tube 13 is provided with a cap at its end (not shown), and the cap blows out the air in the horizontal direction while preventing the medium 6 and the like from entering.
The jet air improves the fluidity of the medium 6, and the medium 6 falls smoothly from the dispersion member 7.

Further, the state of adhesion or dropping of the medium 6 is observed with a television camera 41, and the adjustment of the gap and the presence / absence and strength of vibration of the dispersing member 7 are changed. By controlling the passage amount, the heat exchanger 1 is operated efficiently and stably.

The medium 6 dropped from the dispersing member 7 is caused to flow on the uppermost tray 33 in the low-temperature chamber 3 by the low-temperature gas 10 ejected from a number of holes 46a provided in the tray 33, Give 10 heat. A part of the medium 6 is placed in the tray 33 below the hole 46a.
To fall. Due to the deposit attached to the medium 6, the medium 6
Tends to adhere to the surface of the tray 33.
Since the medium 3 is vibrated by the vibration means 12, even if the medium 6 adheres to the surface of the tray 33, the medium 6 is immediately separated.

In this way, the medium 6 gives a large amount of heat to the low-temperature gas 10 on the trays 33 in a plurality of stages and when descending the trays 33 in the plurality of stages. Heated low temperature gas 1
1 is discharged from the low temperature gas outlet 32 and used as combustion air or the like.

The medium 6 that has given heat to the low-temperature gas 11 in the low-temperature chamber 3 drops to the cone 3a at the bottom of the low-temperature chamber 3, and then moves to the transfer means 5 while keeping the discharge pipe 34 filled. The transfer means 5 is illustrated as an air lift type that transfers the medium 6 upward by air, but may be a bucket conveyor type or the like.

In the low-temperature chamber 3, the surface of the medium 6 comes into contact with the low-temperature gas 11 and its temperature drops considerably.
The deposits that have adhered to the surface of the medium 6 solidify. The medium 6 moved to the ejector 27 below the transfer means 5 is lifted by the compressed air 29 into the medium hopper 28 above, and is injected into the high temperature chamber 2 through the medium inlet 24. At this time, in the ejector 27 and the air lift pipe,
Due to the collision between the media 6 and the like, the attached matter is separated. The deposit is introduced into the high-temperature chamber 2 from the medium inlet 24 together with the medium 6, and rides on the gas flow of the high-temperature gas 10, and the hot gas exit 22
Is discharged from

Some of the deposits are separated in the low-temperature chamber 3 and discharged together with the low-temperature gas 10.
Is used for the combustion air of the melting furnace 51, so that the deposits also burn, and there is no particular problem.

In the above embodiment, the tray 23 of the high temperature chamber 2
Is a tilt type, and the tray 33 of the low temperature chamber 3 is a horizontal type. However, the tray 23 of the high temperature chamber 2 is horizontal, and the tray 33 of the low temperature chamber 3 is tilted.
Either of the types 3 and 33 may be used, and both types may be used in each of the trays 23 and 33 individually. Further, the inclination and the vibration application of each of the trays 23 and 33 can be appropriately selected. That is, unlike the above embodiment, the attachment of the vibration means 12 to both trays 23 and 33 may be stopped, or the trays 23 and 33 may be leveled to provide only the vibration means 12.

[0045]

As described above, according to the present invention, even if the adhesive substance is mixed with the high-temperature gas, the movement of the medium on the tray can be made smooth, and the upper heat exchange chamber and the lower heat exchange chamber can be moved. The circulation of the medium during
An efficient heat exchange action can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic sectional front view of one embodiment.

FIG. 2 is an enlarged view of the heat exchanger of FIG.

FIG. 3 is an enlarged view of a main part of FIG. 2;

FIG. 4 is an enlarged view of a main part of FIG. 2;

FIG. 5 is a cutaway plan view of FIG. 4;

FIG. 6 is an enlarged view of a main part of FIG. 2;

FIG. 7 is a cut-away plan view of FIG. 6;

FIG. 8 is a schematic diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 High temperature room 3 Low temperature room 4 Communication pipe 5 Transfer means 6 Medium 7 Dispersion member 8 Vibration means 9 Gap adjusting means 10 High temperature gas 11 Low temperature gas 12 Vibration means 13 Air tube 20 Holding member 23 Tray 27 Ejector 28 Medium hopper 29 Compressed air 31 Low temperature gas inlet 32 Low temperature gas outlet 33 Tray 34 Medium outlet 35 Transmission rod 36 Vibrator 38 Eccentric disk 42 Perforated plate 46 Perforated plate 51 Incineration ash melting furnace

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Takashi Mukai 1-12-19 Kitahorie, Nishi-ku, Osaka-shi Inside Kurimoto Iron Works Co., Ltd. (72) Hirotoshi Murata 5-1-1 Ageocho, Yao City 8 shares F term in the Naniwa Furnace Research Laboratory (reference) 3K061 NB03

Claims (3)

[Claims] 1. A heat exchange chamber 2 through which a high-temperature gas 10 flows, and a heat exchange chamber 3 through which a low-temperature gas 11 flows,
The heat exchange chambers 2 and 3 are provided with trays 23 and 33 in a plurality of stages, respectively, and the medium 6 is sequentially dropped onto the trays 23 and 33 and circulated between the heat exchange chambers 2 and 3; In the heat exchanger 1 in which the medium 6 absorbs heat from the high temperature gas 10 in the upper heat exchange chamber 2 and the low temperature gas 11 absorbs heat from the medium 6 in the lower heat exchange chamber 3, the high temperature gas 10 is incinerated. A heat exchanger, which is exhaust gas discharged from a melting furnace for melting ash, wherein the trays 23 and 33 of at least one of the heat exchange chambers 2 and 3 are inclined downward. 2. A heat exchange chamber 2 through which a high-temperature gas 10 flows, and a heat exchange chamber 3 through which a low-temperature gas 11 flows,
The heat exchange chambers 2 and 3 are provided with trays 23 and 33 in a plurality of stages, respectively, and the medium 6 is sequentially dropped onto the trays 23 and 33 and circulated between the heat exchange chambers 2 and 3; In the heat exchanger 1 in which the medium 6 absorbs heat from the high temperature gas 10 in the upper heat exchange chamber 2 and the low temperature gas 11 absorbs heat from the medium 6 in the lower heat exchange chamber 3, the high temperature gas 10 is incinerated. A heat exchanger, which is exhaust gas discharged from a melting furnace for melting ash, wherein the vibration means 12 is attached to each of the trays 23 and 33 of at least one of the heat exchange chambers 2 and 3. 3. Each tray 2 provided with said vibration means 12
3. The heat exchanger according to claim 2, wherein each of the third and the third is inclined downward.