JP6977683B2 - Incinerator ash cooling device and incinerator ash cooling method - Google Patents

Description

The present invention relates to an incinerator ash cooling device for cooling incinerator ash discharged from a waste incinerator that incinerates waste such as municipal waste, and an incinerator ash cooling method.

The incinerated ash generated when waste such as municipal waste and industrial waste is incinerated in an incinerator is discharged from the incinerator, put into an ash cooling tank, extinguished and cooled by the cooling water in the tank, and then extinguished from the ash cooling tank. It has been carried out and disposed of in mine.

In the ash cooling tank that receives the incinerator ash discharged from the incinerator and cools it with cooling water, particulate matter called scum generated from the components dissolved or separated from the incinerator ash floats and accumulates on the water surface of the cooling water. Scum may be deposited with a thickness of several tens of centimeters, which may hinder the removal of incinerated ash after cooling from the ash cooling tank. It is removed by.

US Pat. It is stated that scum can be prevented from flowing into areas where the operation of the member may be hindered.

JP-A-2002-340323 JP 2006-317110

In order to remove the scum, sprinkling spray and aeration for the disappearance of the scum requires the installation of equipment for that purpose and its operating cost, and the burden on the operator is large due to the removal of the scum by manual work. There is a problem that it becomes expensive and the operating cost is high.

In addition, when the incinerator ash is carried out from the ash cooling tank, a scum adheres to the carry-out conveyor, which makes the conveyor inoperable, and the water level sensor that measures the water level of the ash cooling tank is buried in the scum. There is a problem that the operation of the ash cooling tank is hindered, such as the inability to measure.

Under such circumstances, in Patent Documents 1 and 2, by using the described extrusion member, it is possible to prevent the scum from flowing into the region where the operation of the extrusion member is hindered, but the scum generation itself. Cannot be suppressed.

In view of such circumstances, the present invention provides an incinerator ash cooling device and an incinerator ash cooling method in which the incinerator ash generated in an incinerator is less likely to generate scum when the incinerator is brought into the ash cooling tank. The challenge is to provide.

According to the present invention, the above-mentioned problems are solved by an incinerator ash cooling device having the following configuration and an incinerator ash cooling method using the same.

[Incinerator ash cooling device]
In the incineration ash cooling device that cools the incineration ash discharged from the waste incinerator, an ash cooling tank that stores cooling water and receives and cools the incineration ash from the incinerator, and cooling water cooling that cools the cooling water in the ash cooling tank. The cooling water temperature of the ash cooling tank is cooled to a predetermined temperature or less based on the means, the cooling water temperature measuring means for measuring the cooling water temperature of the ash cooling tank, and the cooling water temperature measured value measured by the cooling water temperature measuring means. The cooling water temperature controlling means for controlling the cooling water cooling means is provided, and the predetermined temperature is set to 65 ° C., which is a temperature derived from the correspondence between the cooling water temperature and the effect of suppressing the generation of scum from the incinerated ash. An incineration ash cooling device characterized by being

In the present invention, the cooling water cooling means can be a cooling water circulation cooling device that receives the cooling water of the ash cooling tank, cools the cooling water, and returns the cooling water to the ash cooling tank.

In the present invention, the cooling water cooling means includes a cooling unit provided in the ash cooling tank for cooling the cooling water, and a refrigerant circulation cooling system that sends the cooled refrigerant to the cooling unit and receives the heated refrigerant from the cooling unit to cool the cooling water. It can also be configured with a device.

In the present invention, the cooling water cooling means includes a cooling jacket provided around the ash cooling tank to cool the cooling water, and a refrigerant circulation in which the cooled refrigerant is sent to the cooling jacket and the cooled refrigerant is received from the cooling jacket and cooled. It can also be configured with a cooling device.

[Incinerator ash cooling method]
In the incineration ash cooling method for cooling the incineration ash discharged from the waste incinerator, the incineration ash is received and cooled in the ash cooling tank that stores the cooling water, and the cooling water in the ash cooling tank is cooled by the cooling water cooling means. The cooling water cooling means is controlled by the cooling water temperature control means so as to cool the cooling water temperature of the ash cooling tank to a predetermined temperature or less based on the cooling water temperature measurement value measured by the cooling water temperature measuring means, and the predetermined temperature is set. , An incineration ash cooling method characterized in that the temperature is set to 65 ° C., which is a temperature derived from the correspondence between the cooling water temperature and the effect of suppressing the generation of scum from the incineration ash.

In the present invention, the cooling water cooling means is formed as a cooling water circulation cooling device that receives and cools the cooling water of the ash cooling tank and returns it to the ash cooling tank, and the cooling water cooled by the cooling water circulation cooling device is transferred to the ash cooling tank. It can be sent in and cooled by receiving the cooling water after the temperature rise from the ash cooling tank.

In the present invention, the cooling water cooling means is provided in an ash cooling tank and has a cooling unit for cooling the cooling water, and a refrigerant circulation cooling system in which the cooled refrigerant is sent to the cooling unit and the cooled refrigerant is received from the cooling unit to cool the cooling water. It is also possible to form the device as a device, send the refrigerant cooled by the refrigerant circulation cooling device to the cooling unit, and receive the cooled refrigerant from the cooling unit to cool the cooling unit.

In the present invention, the cooling water cooling means is provided around the ash cooling tank to cool the cooling water, and the refrigerant circulation that sends the cooled refrigerant to the cooling jacket and receives the heated refrigerant from the cooling jacket to cool the cooling water. It can also be formed as a cooling device, and the refrigerant cooled by the refrigerant circulation cooling device is sent to the cooling jacket, and the refrigerant after the temperature rise is received from the cooling jacket to be cooled.

[Principle of invention]
<Root cause analysis of scum generation>
In the cause analysis of scum generation from incinerator described below, the grate type incinerator is analyzed as an incinerator, but the type of incinerator is not limited to this, and it is discharged from other types of incinerators. Scum is generated by the same mechanism for incinerated ash.
(I) High-temperature incinerator is put into the ash cooling tank from the waste incinerator, and it is contained in the incinerator, and small particle particles generated by the reaction from the incinerator are suspended and accumulated on the surface of the cooling water. Become a scum. Most of the scum is calcium hydroxide particles generated in cooling water from calcium oxide contained in incineration ash, and aluminate-based cement hydrate particles reacted in cooling water from incineration ash components, and calcium hydroxide particles. Partially dissolves in cooling water, but insoluble matter floats, and aluminate-based cement hydrate particles do not dissolve in water and float, and both become scum.

(Ii) In the grate-type waste incinerator, after the waste is burned in the combustion grate, the unburned portion is post-combusted in the post-combustion grate. By ventilating a small amount of air, the unburned content is completely burned. Since the cooling action by air blowing from the lower part of the post-combustion grate is small, the incinerated ash on the post-combustion grate is kept at a high temperature. In addition, the calcium contained in the incinerated ash exists in the form of calcium oxide in the incinerated ash due to combustion at a high temperature, and the incinerated ash is discharged to the ash cooling tank, and the calcium oxide and water of the incinerated ash are discharged in the ash cooling tank. Calcium hydroxide produced by the reaction with is present, so that the pH of the cooling water in the ash cooling tank is kept high.

(Iii) When incineration ash containing a large amount of calcium oxide is added to the high pH cooling water of the ash cooling tank, most of the calcium hydroxide particles generated by the reaction between calcium oxide in the incineration ash and water become water. It does not dissolve, and a large amount of insoluble calcium hydroxide particles are generated, which floats and becomes scum.

<Suppression of scum generation>
(1) The higher the temperature of the cooling water in the ash cooling tank, the smaller the solubility of the calcium hydroxide particles, the larger the amount of calcium hydroxide insoluble matter present, and the easier it is for scum to occur. By lowering the temperature of the cooling water in the ash cooling tank, which was conventionally as high as 80 ° C. or higher, and preferably by lowering the temperature of the cooling water in the ash cooling tank to 65 ° C. or lower, calcium hydroxide to the cooling water can be added. It increases the solubility and reduces the amount of calcium hydroxide present as an insoluble matter to suppress scum generation.

(2) The reaction rate for forming aluminate-based cement hydrate is highly temperature-dependent, and the higher the temperature of the cooling water in the ash cooling tank, the higher the reaction rate for forming aluminate-based cement hydrate, resulting in scum. It will be easier. By lowering the temperature of the cooling water in the ash cooling tank, preferably the temperature of the cooling water in the ash cooling tank is 65 ° C. or lower, the reaction rate for forming the aluminate-based cement hydrate is lowered, and the amount of production is increased. It reduces and suppresses the generation of scum.

As described above, the correspondence between the cooling water temperature of the ash cooling tank and the effect of suppressing the generation of scum can be clarified, and from this correspondence, the cooling water temperature of the ash cooling tank is preferably 65 ° C. or lower as a predetermined temperature. By cooling to, the generation of scum can be effectively suppressed.

According to the present invention, by lowering the temperature of the cooling water in the ash cooling tank to preferably 65 ° C. or lower, the solubility of calcium hydroxide in the cooling water is increased and it exists as an insoluble component of calcium hydroxide. It is possible to suppress the generation of scum by reducing the amount of slaked water, and to reduce the reaction rate of the formation of aluminate-based cement hydrate to reduce the amount of scum. Thus, since the generation of scum in the ash cooling tank can be suppressed, equipment such as sprinkling spray and aeration, which have been conventionally used, is not required, and the operating cost for operating the equipment and the scum removal work cost by the operator can be reduced. In addition, problems such as the conveyor that carries out the incinerator ash from the cooling tank becoming inoperable and the water level sensor becoming inoperable do not occur.

It is a schematic block diagram of the incinerator ash cooling apparatus which concerns on one Embodiment of this invention, (A) is an example, (B) is a modification, (C) shows a further modification.

FIG. 1 shows an outline configuration of an incinerator ash cooling device as an embodiment of the present invention, (A) is an example, (B) is a modified example, and (C) is another modified example. The present embodiment has an incinerator that incinerates waste and an ash cooling tank that receives and cools incinerator ash from the incinerator, but the incinerator simply discharges incinerator regardless of the type and structure. In FIGS. 1 (A), (B), and (C), the incinerator is not shown because it is related to the present invention only in that the incinerator is used.

The ash cooling tank 10 shown in FIG. 1A has an incineration ash cooling unit 11 that stores cooling water WA and an incineration ash receiving unit that extends upward from the incineration ash cooling unit 11 and opens upward. 12 and a cooling ash discharging unit 13 which is opened downward at the upper left portion of the incineration ash cooling unit 11 to discharge the incineration ash as cooling ash after cooling, and the incineration ash cooling unit 11 has a cooling ash discharging unit 13. , A cooling water thermometer 14 for measuring the temperature of the cooling water WA is arranged. The opening of the incinerator ash receiving section 12 is located below the incinerator ash discharging section of an incinerator (not shown), and receives a drop supply of incinerator ash. Further, in the incinerator ash cooling unit 11, the bottom of the tank facing the cooling ash discharging unit 13 has an inclined surface, and the cooling ash is conveyed toward the cooling ash discharging unit 13 along the inclined surface. (Not shown) is provided.

A cooling water circulation cooling device 20 as a cooling water cooling means is provided outside the ash cooling tank 10. The cooling water circulation cooling device 20 includes a cooling water tank 21 that receives cooling water from the ash cooling tank 10, a cooling unit (not shown) that is housed in the cooling water tank 21 and cools the cooling water, and the cooling unit. The cooling water cooled by the above method is sent to the ash cooling tank 10 via the pipe 22, and the cooling water heated by the contact with the incinerated ash in the ash cooling tank 10 is pulled back to the external cooling water tank 21. It has a pump (not shown) that circulates the cooling water and a regulating valve (not shown) that regulates the flow rate of cooling water. Further, a cooling water temperature control device 24 is provided as a cooling water temperature control means, and the cooling water temperature of the ash cooling tank is cooled to a predetermined temperature or less based on the cooling water temperature measurement value measured by the cooling water temperature gauge 14. As such, at least one of the cooling capacity of the cooling unit of the cooling water circulation cooling device 20, the flow capacity of the pump, and the opening degree of the regulating valve is controlled.

In the present embodiment having such a configuration, the temperature of the cooling water in the incineration ash cooling unit 11 is measured by the cooling water thermometer 14, and even if the incineration ash falls and comes into contact with the cooling water, the temperature of the cooling water rises. At least one of the cooling unit, the pump, and the adjusting valve of the cooling water circulation cooling device 20 is controlled so that the measured cooling water temperature is within 65 ° C., which is an appropriate predetermined temperature or less. As a result, incinerator ash is less likely to scum. The reasons why scum is unlikely to occur are as follows.

(1) The higher the temperature of the cooling water in the ash cooling tank, the smaller the solubility of the calcium hydroxide particles, the larger the amount of calcium hydroxide insoluble matter present, and the easier it is for scum to occur. By lowering the temperature of the cooling water in the ash cooling tank, which was conventionally as high as 80 ° C. or higher, and preferably by lowering the temperature of the cooling water in the ash cooling tank to 65 ° C. or lower, calcium hydroxide to the cooling water is added. Increases the solubility of calcium hydroxide and reduces the amount of calcium hydroxide present as an insoluble matter to suppress scum generation.

(2) The reaction rate for forming aluminate-based cement hydrate is highly temperature-dependent, and the higher the temperature of the cooling water in the ash cooling tank, the higher the reaction rate for forming aluminate-based cement hydrate, resulting in scum. It will be easier. By lowering the temperature of the cooling water in the ash cooling tank, preferably the temperature of the cooling water in the ash cooling tank is 65 ° C. or lower, the reaction rate for forming the aluminate-based cement hydrate is lowered, and the amount of production is increased. To suppress the generation of scum.

Thus, the incinerator ash is cooled by the incinerator ash cooling unit 11 and then discharged from the cooling ash discharge unit 13 in a state where the scum is not generated or is suppressed.

In the example of FIG. 1B, the cooling water WA in the incineration ash cooling unit 11 is maintained at a temperature within a predetermined range by circulating the refrigerant instead of the cooling water circulation in FIG. 1A. Since the ash cooling tank 10 is the same as that of FIG. 1 (A) only different from the example of FIG. 1 (A), the same reference numerals are given to the parts common to those of FIG. 1 (A), and the description thereof will be omitted. ..

In FIG. 1B, instead of the cooling water circulation cooling device 20 in FIG. 1A, a cooling unit 33 provided in the ash cooling tank to receive the refrigerant and cool the cooling water, and the refrigerant cooled to the cooling unit 33 are used. It has a refrigerant circulation cooling device 30 that receives and cools the cooled refrigerant from the feed cooling unit. The refrigerant circulation cooling device 30 is cooled by the refrigerant tank 31 that receives the refrigerant from the cooling unit 33, a cooling unit (not shown) that is housed in the refrigerant tank 31 and cools the refrigerant, and the cooling unit. The refrigerant is sent to the cooling unit 33 in the ash cooling tank 10 through the pipe 32, and the refrigerant heated by heat exchange with the cooling water in the ash cooling tank 10 is pulled back to the refrigerant tank 31. It has a circulating pump (not shown) and a regulating valve (not shown) that regulates the flow rate of the refrigerant. Further, a cooling water temperature control device 34 is provided as a cooling water temperature control means, and the cooling water temperature of the ash cooling tank is cooled to a predetermined temperature or less based on the cooling water temperature measurement value measured by the cooling water temperature gauge 14. At least one of the cooling capacity of the cooling unit of the refrigerant circulation cooling device 30, the flow capacity of the pump, and the opening degree of the regulating valve is controlled so as to be performed.

In the present embodiment having such a configuration, the temperature of the cooling water in the incineration ash cooling unit 11 is measured by the cooling water thermometer 14, and even if the incineration ash falls and comes into contact with the cooling water, the temperature of the cooling water rises. , The cooling capacity of the cooling unit of the cooling unit of the refrigerant circulation cooling device 30, the flow capacity of the pump, and the opening degree of the adjusting valve so that the measured cooling water temperature is within 65 ° C., which is below the appropriate predetermined temperature. Control at least one of them. As a result, incinerator ash is less likely to scum.

The example of FIG. 1 (C) is the same as the example of FIG. 1 (B) in that the cooling water in the incineration ash cooling unit 11 is cooled by using the refrigerant, but the pipe 32A that circulates the refrigerant cools the incineration ash. It differs from FIG. 1 (B) in that it is not connected to the cooling unit 33 in the unit 11 but is connected to the cooling jacket 11A provided on the outer wall of the tank of the incineration ash cooling unit 11, and the others are shown in FIG. 1 (B). ), Therefore, the same reference numerals are given to the parts common to those in FIG. 1 (B), and the description thereof will be omitted.

In FIG. 1C, the incinerator ash cooling unit 11 is provided with a cooling jacket 11A through which the refrigerant flows on the outer wall of the tank. The cooling jacket 11A is formed over a wide surface around the outer wall of the tank of the incineration ash cooling unit 11, and the pipe 32A of the refrigerant circulation cooling device 30 is connected to the cooling jacket 11A. Thus, the cooling water is cooled through the outer wall of the incinerator ash cooling unit 11.

In the present embodiment having such a configuration, the temperature of the cooling water in the incineration ash cooling unit 11 is measured by the cooling water thermometer 14, and even if the incineration ash falls and comes into contact with the cooling water, the temperature of the cooling water rises. , The cooling capacity of the cooling unit of the cooling unit of the refrigerant circulation cooling device 30, the flow capacity of the pump, and the opening degree of the adjusting valve so that the measured cooling water temperature is within 65 ° C., which is below the appropriate predetermined temperature. Control at least one of them. As a result, incinerator ash is less likely to scum.

In the present embodiment, the temperature of the cooling water in the ash cooling tank is preferably 65 ° C. or lower. At this temperature, the solubility of calcium hydroxide is increased and the reaction rate for forming the aluminate-based cement hydrate is increased. It is effective in reducing the temperature.

10 Ash cooling tank 11A Cooling jacket 20 Cooling water cooling means (cooling water circulation cooling device)
21 Cooling water tank 30 Cooling water cooling means (refrigerant circulation cooling device)
31 Refrigerant tank 34 Cooling water temperature control device

Claims (8)

In the incineration ash cooling device that cools the incineration ash discharged from the waste incinerator, an ash cooling tank that stores cooling water and receives and cools the incineration ash from the incinerator, and cooling water cooling that cools the cooling water in the ash cooling tank. The cooling water temperature of the ash cooling tank is cooled to a predetermined temperature or less based on the means, the cooling water temperature measuring means for measuring the cooling water temperature of the ash cooling tank, and the cooling water temperature measured value measured by the cooling water temperature measuring means. The cooling water temperature controlling means for controlling the cooling water cooling means is provided, and the predetermined temperature is set to 65 ° C., which is a temperature derived from the correspondence between the cooling water temperature and the effect of suppressing the generation of scum from the incinerated ash. An incineration ash cooling device characterized by being The incineration ash cooling device according to claim 1, wherein the cooling water cooling means is a cooling water circulation cooling device that receives the cooling water of the ash cooling tank, cools it, and returns it to the ash cooling tank. The cooling water cooling means includes a cooling unit provided in the ash cooling tank to cool the cooling water, and a refrigerant circulation cooling device that sends the cooled refrigerant to the cooling unit and receives the heated refrigerant from the cooling unit to cool the cooling water. The incineration ash cooling device according to claim 1. The cooling water cooling means includes a cooling jacket provided around the ash cooling tank to cool the cooling water, and a refrigerant circulation cooling device that sends the cooled refrigerant to the cooling jacket and receives the heated refrigerant from the cooling jacket to cool the cooling water. The incineration ash cooling device according to claim 1, wherein the incineration ash cooling device is configured. In the incineration ash cooling method for cooling the incineration ash discharged from the waste incinerator, the incineration ash is received and cooled in the ash cooling tank that stores the cooling water, and the cooling water in the ash cooling tank is cooled by the cooling water cooling means. The cooling water cooling means is controlled by the cooling water temperature control means so as to cool the cooling water temperature of the ash cooling tank to a predetermined temperature or less based on the cooling water temperature measurement value measured by the cooling water temperature measuring means, and the predetermined temperature is set. , An incineration ash cooling method characterized in that the temperature is set to 65 ° C., which is a temperature derived from the correspondence between the cooling water temperature and the effect of suppressing the generation of scum from the incineration ash. The cooling water cooling means is formed as a cooling water circulation cooling device that receives the cooling water of the ash cooling tank, cools it, and returns it to the ash cooling tank, and sends the cooling water cooled by the cooling water circulation cooling device to the ash cooling tank. The incineration ash cooling method according to claim 5, wherein the cooling water after the temperature rise is received from the ash cooling tank and cooled. The cooling water cooling means is formed as a cooling unit provided in the ash cooling tank to cool the cooling water and a refrigerant circulation cooling device that sends the cooled refrigerant to the cooling unit and receives the heated refrigerant from the cooling unit to cool the cooling water. The incineration ash cooling method according to claim 5, wherein the refrigerant cooled by the refrigerant circulation cooling device is sent to a cooling unit, and the cooling unit receives the cooled refrigerant from the cooling unit to cool the cooling unit. The cooling water cooling means is formed as a cooling jacket provided around the ash cooling tank to cool the cooling water, and a refrigerant circulation cooling device that sends the cooled refrigerant to the cooling jacket and receives the heated refrigerant from the cooling jacket to cool the cooling water. The incineration ash cooling method according to claim 5, wherein the refrigerant cooled by the refrigerant circulation cooling device is sent to a cooling jacket, and the cooling is received from the cooling jacket after the temperature is raised.

Images