JP2020193804A - Fluidized furnace and cooling method therefor - Google Patents

Abstract

To propose a fluidized furnace including means of injecting water for cooling fluidized medium into a pipe for supplying an object to be treated in the fluidized furnace, and a method for injecting water for cooling the fluidized medium.SOLUTION: A fluidized furnace is configured such that a sand layer is provided at a lower part of a furnace body; combusted air supply means of supplying combusted air is included in the sand layer; a temperature sensor for measuring a temperature of the sand layer is inserted into a side wall of the furnace body; and a pipe for supplying an object to be treated is connected to the side wall of the furnace body. To the object to be treated in the pipe, a terminal part of a first water injection pipe for supplying water is connected, and in the first water injection pipe, water injection control means driven based on a measurement result of the temperature sensor is provided.SELECTED DRAWING: Figure 1

Description

The present invention relates to a flow furnace and a cooling method thereof. A flow furnace provided with a means for injecting water for cooling the flow medium into an object to be treated such as sewage sludge, and an object to be treated are injected according to the temperature of the flow medium. It relates to a cooling method for adjusting the flow rate of water.

In the conventional flow furnace, a water gun is provided above the freeboard part of the flow furnace, and when the temperature of the freeboard part of the flow furnace becomes higher than a predetermined temperature, the freeboard part is connected via the water gun. The technique of spraying water is known. (See Patent Document 1)
Further, a nozzle is provided near the upper part of the flow medium of the flow furnace, and when the temperature of the flow medium of the flow furnace becomes higher than a predetermined temperature, water is directly supplied to the flow medium through the nozzle. The technology to do is known. (See Patent Document 2)

Japanese Unexamined Patent Publication No. 2005-274025 Japanese Unexamined Patent Publication No. 9-236233

However, in the technique of Patent Document 1, the water sprayed from the water gun to the free board portion reaches the vicinity of the flow medium provided in the lower part of the flow furnace by convection flowing from the lower part to the upper part of the flow furnace. Since this is not possible, there is a risk that the flow medium having become higher than the predetermined temperature cannot be sufficiently cooled.

Further, in the technique of Patent Document 2, the water supplied from the nozzle comes into direct contact with the fluid medium and rapidly cools the fluid medium having a temperature higher than a predetermined temperature, so that the fluid medium cracks and the fluid medium becomes cracked. Since the particle size becomes smaller, the amount of the flow medium discharged from the flow furnace along with the combustion exhaust gas may increase. As a result, the amount of the flow medium in the flow furnace is reduced, so that it is expected that the running cost will increase, such as the increase in the flow medium to be replenished and the collection and processing of the accompanying flow medium.

Therefore, the present invention proposes a flow furnace provided with a means for injecting water for cooling the flow medium into a pipe for supplying an object to be processed in the flow furnace, and a method for injecting water for cooling the flow medium.

The present invention and the effects of action that have solved the above problems are as follows.
In the first invention, a sand layer is provided in the lower part of the furnace body, a combustion air supply means for supplying combustion air into the sand layer is provided, and a temperature sensor for measuring the temperature of the sand layer is inserted in the side wall of the furnace body. In a flow furnace in which a pipe for supplying an object to be processed is connected to the side wall of the furnace body.
The end portion of the first water injection pipe that supplies water to the object to be treated in the pipe is connected, and the first water injection pipe is provided with a water injection control means that drives based on the measurement result of the temperature sensor. It is a feature.

(Action effect)
Since the end of the first water injection pipe that supplies water to the object to be treated is connected to the pipe and a water injection control means that drives based on the measurement result of the temperature sensor is provided, water is supplied to the object to be processed according to the sand layer temperature. By supplying water to increase the water content of the object to be treated and increasing the amount of heat consumed by the latent heat of evaporation, the sand layer can be cooled and the flow furnace can be operated stably.

The second invention is characterized in that, in the configuration of the first invention, the water injection control means includes a first regulating valve for adjusting the flow rate of water and an on-off valve for starting and stopping the supply of water.

(Action effect)
Since the water injection control means includes a first regulating valve that adjusts the flow rate of water and an on-off valve that starts and stops the supply of water, even if the first regulating valve malfunctions, the on-off valve is driven to drive the furnace body. It is possible to prevent unnecessary water from being supplied to the pot.

The third invention is characterized in that, in the configuration of the first or second invention, the end portion of the first water injection pipe is connected to a portion of the pipe close to the side wall of the furnace body.

(Action effect)
Since the end of the first water injection pipe is connected to the part of the pipe near the side wall of the furnace body, the effect of pressure loss is reduced and the object to be treated with a high water content is supplied to the furnace body at a stable pace. can do.

According to the fourth invention, in the configuration of any one of the first to third inventions, in the configuration of the first or second invention, the first portion of the side wall is biased downward from the middle in the vertical direction. It is characterized by connecting the end of the water injection pipe.

(Action effect)
Since the end of the first water injection pipe was connected to a portion of the side wall that was biased below the middle in the vertical direction, a large amount of water contained in the object to be treated evaporates near the flow part of the sand layer. It is possible to prevent damage to the sand layer.

In the fifth invention, a sand layer is provided in the lower part of the furnace body, a supply pipe for supplying combustion air is inserted in the sand layer, and a temperature sensor for measuring the temperature of the sand layer is inserted in the upper part of the sand layer. In the cooling method of a flow furnace in which a pipe for supplying an object to be processed is connected to the side wall of the body,
A first adjusting valve that connects the end of the first water injection pipe that supplies water to the object to be treated to the pipe and adjusts the flow rate of water to the first water injection pipe, and opens and closes on the downstream side of the first adjustment valve. Provide a valve,
When the temperature of the sand layer is higher than a predetermined set temperature, the on-off valve is driven to open a portion of the first water injection pipe on the downstream side of the first regulating valve, and then the first regulating valve is driven. Adjust the water flowing through the first water injection pipe to the specified flow rate,
When the temperature of the sand layer becomes lower than a predetermined set temperature, the first regulating valve is driven to stop the water flowing through the first water injection pipe, and then the on-off valve is driven to perform the first note. It is characterized by closing a portion of the water pipe on the downstream side of the first regulating valve.

(Action effect)
A first regulating valve that connects the end of the first water injection pipe that supplies water to the object to be treated to the pipe and adjusts the flow rate of water to the first water injection pipe, and an on-off valve on the downstream side of the first adjustment valve are provided. When the temperature of the sand layer is higher than the predetermined set temperature, the on-off valve is driven to open the downstream part of the first regulating valve in the first water injection pipe, and then the first regulating valve is driven to perform the first. After adjusting the water flowing through the water injection pipe to a predetermined flow rate and when the temperature of the sand layer becomes lower than the predetermined set temperature, drive the first regulating valve to stop the water flowing through the first water injection pipe. , The on-off valve is driven to close the downstream part of the first regulating valve in the first water injection pipe, so when the sand layer becomes higher than the predetermined set temperature, water is supplied to the object to be treated and the object to be treated is treated. The water content of the object can be increased, the amount of heat consumed by the latent heat of evaporation can be increased, the sand layer can be cooled, and the flow furnace can be operated stably. Further, even if the first regulating valve malfunctions, the on-off valve can be driven to prevent unnecessary water from being supplied to the furnace body.

The sixth invention is characterized in that, in the configuration of the fifth invention, the first regulating valve is driven to increase or decrease the flow rate of water flowing through the first water injection pipe according to the temperature of the sand layer.

(Action effect)
Since the first regulating valve is driven to increase or decrease the flow rate of water flowing through the first water injection pipe according to the temperature of the sand layer, the water content of the water contained in the object to be treated is increased or decreased, and the amount of heat consumed by the latent heat of vaporization is increased or decreased. Therefore, the sand layer can be cooled quickly and the flow furnace can be operated stably.

In the seventh invention, in the configuration of the fifth or sixth invention, the end portion of the second water injection pipe for supplying water to be sprayed to the free board portion is connected to the upper part of the side wall of the furnace body, and water is connected to the second water injection pipe. A second regulating valve is provided to adjust the flow rate of
After driving the on-off valve to open a portion of the first water injection pipe on the downstream side of the first regulating valve, driving the second regulating valve to adjust the water flowing through the second water injection pipe to a predetermined flow rate. It is characterized by.

(Action effect)
The end of the second water injection pipe that supplies water to be sprayed to the free board is connected to the upper part of the side wall of the furnace body, the second water injection pipe is provided with a second adjustment valve that adjusts the flow rate of water, and the on-off valve is driven. After opening the downstream part of the first regulating valve in the first water injection pipe, the second regulating valve is driven to adjust the water flowing through the second water injection pipe to a predetermined flow rate, so that the free board of the furnace body is used. It is possible to cool the part and operate the flow furnace more stably.

In the eighth aspect of the invention, in the configuration of any one of the fifth to seventh aspects, the terminal portion of the third water injection pipe for supplying water to be sprayed to the discharge portion is connected to the upper end portion of the side wall of the furnace body. A third regulating valve for adjusting the flow rate of water is provided in the third water injection pipe.
After driving the on-off valve to open the downstream part of the first regulating valve in the first water injection pipe, or driving the second regulating valve to adjust the water flowing through the second water injection pipe to a predetermined flow rate. After that, the third adjusting valve is driven to adjust the water flowing through the third water injection pipe to a predetermined flow rate.

(Action effect)
The end of the third water injection pipe that supplies water to be sprayed to the discharge part is connected to the upper end of the side wall of the furnace body, and the third water injection pipe is provided with a third adjustment valve that adjusts the flow rate of water.
After driving the on-off valve to open the downstream part of the first regulating valve in the first water injection pipe, or after driving the second regulating valve to adjust the water flowing through the second water injection pipe to a predetermined flow rate. Since the third regulating valve is driven to adjust the water flowing through the third water injection pipe to a predetermined flow rate, the discharge portion of the furnace body can be cooled and the flow furnace can be operated more stably.

By increasing the water content of the water contained in the object to be treated and increasing the amount of heat consumed by the latent heat of vaporization, the sand layer that has become higher than the predetermined set temperature can be cooled, and the flow furnace can be operated stably. ..

It is explanatory drawing of the flow furnace. It is a connection diagram of a controller. It is explanatory drawing of the cooling method of a flow medium.

As shown in FIG. 1, the furnace body 10 of the flow furnace has a side wall 11 formed in a cylindrical shape, a lower wall 12 formed so as to project downward, and an upper wall 12 formed so as to project upward. It is formed from the wall 13.

A sand layer 20 serving as a flow medium formed of sand or the like having a certain particle size or more is provided in the lower part of the furnace body 10. In the sand layer 20, a dispersion pipe 21 having a large number of discharge ports for supplying combustion air is arranged as the combustion air supply means A. As a result, when the flow furnace is in operation, that is, when a predetermined amount of dehydrated cake to be processed is supplied to the furnace body 10 and the dehydrated cake is burned in the furnace body 10, the sand layer is formed from the dispersion pipe 21. The combustion air supplied to the 20 20 causes the sand or the like located above the sand layer 20 to flow upward. In the present specification, a portion that flows upward during operation of the flow furnace is referred to as a flow portion 20A, a portion other than that is referred to as a non-fluid portion 20B, and both are collectively referred to as a sand layer 20.
A temperature sensor mounting seat (not shown) for inserting a temperature sensor 64 for measuring the temperature of the sand layer 20 into the furnace is provided on the side wall 11 of the furnace body 10, and the temperature sensor 64 is mounted. The number of temperature sensors 64 may be plurality, and in that case, the temperature distribution of the sand layer 20 in the vertical direction can be measured by installing the temperature sensors 64 at different positions in the vertical direction of the furnace body 10.

The starting end of the dispersion pipe 21 is connected to a combustion air supply port 30 formed in the lower part of the side wall 11 of the furnace body 10. Further, the combustion air supply port 30 of the furnace body 10 and the heat recovery device 70 are connected by a pipe 80. In the heat recovery device 70, the combustion air is heated by the combustion exhaust gas exhausted from the furnace body 10 to the outside, and the temperature of the combustion air flowing through the pipe 80 is maintained above a certain level. As a result, combustion air having a certain temperature or higher can be supplied to the sand layer 20, and the dehydrated cake can be efficiently burned in the furnace body 10. Further, the latent heat of the combustion exhaust gas exhausted from the furnace body 10 to the outside can be efficiently used.

A dehydrated cake, which is an example of an object to be treated, is located in a portion of the side wall 11 of the furnace body 10 that is biased downward from the middle in the vertical direction and is located above the flow portion 20A of the sand layer 20. The object to be processed supply port 31 is formed. The dehydrated cake is an organic waste whose water content is adjusted to 72 to 80% by mass by dehydrating sewage sludge, human waste, etc. containing an organic substance and having a water content of 97 to 98% by mass.

The dehydrated cake supplied to the furnace body 10 from the object to be processed supply port 31 falls between the upper end of the flowing portion 20A and the upper end of the non-flowing portion 20B of the sand layer 20, and the water contained in the dehydrated cake is removed. When it evaporates, it takes away the heat of the flow part 20A at the time of evaporation, acts in the direction of lowering the temperature of the flow part 20A, and the organic matter contained in the dehydrated cake burns to raise the temperature of the free board part of the furnace body 10. Acts on. As a result, when the dehydrated cake is supplied to the furnace body 10, the temperature of the sand layer 20 and the temperature of the freeboard portion can be maintained at the set temperatures, and the flow furnace can be operated stably.

The furnace body 10 shown in FIG. 1 has a height of 12000 mm and an inner diameter of 500 to 9000 mm, the height of the sand layer 20 when not flowing is 3500 mm, and the object supply port 31 to be processed has a height of 5000 mm of the furnace body 10. It is formed at a height of 1500 mm from the sand layer 20 when it is not flowing. The position of the object to be processed supply port 31 varies depending on the flow rate of the combustion exhaust gas supplied from the dispersion pipe 21, but is located at a height of 30 to 50% of the height of the sand layer 20 at the time of non-flow. As a result, the fluctuation of the furnace body 10 can be suppressed and the flow furnace can be operated stably.

The dehydrated cake is stored in the storage tank 40. The discharge port 41 of the storage tank 40 and the supply port 31 of the furnace body 10 are connected by a pipe 42. The pipe 42 has a horizontal portion 43 extending from the discharge port 41 of the storage tank 40 toward the furnace body 10, a vertical portion 44 extending upward from the terminal portion of the horizontal portion 43, and a terminal of the vertical portion 44. It is formed from a horizontal portion 45 extending from the portion toward the object supply port 31 of the furnace body 10. Further, a pump (not shown) selected from a uniaxial screw type pump, a piston pump and the like is provided in the lower part of the storage tank 40. As a result, a certain amount of dehydrated cake can be supplied to the furnace body 10 via the pipe 42, and the dehydrated cake can be stably burned in the furnace body 10.

The end of the water injection pipe (“first water injection pipe” in the claim) 54 that supplies water to the dehydrated cake is connected to the pipe 42. Although the end portion of the water injection pipe 54 can be connected to either the horizontal portion 43 or the vertical portion 44, it is preferable to connect the end portion of the water injection pipe 54 to the horizontal portion 45 in order to reduce the influence of pressure loss. .. Further, in order to further reduce the influence of pressure loss in the horizontal portion 45, it is more preferable to connect the end portion of the water injection pipe 54 to a portion of the horizontal portion 45 close to the object to be supplied port 31. As a result, when the temperature of the sand layer 20 rises above the set temperature, water is supplied to the dehydrated cake via the water injection pipe 54 to increase the water content of the dehydrated cake, and the vicinity of the flowing portion 20A of the sand layer 20. The sand layer 20 can be cooled by increasing the amount of water that evaporates in the water and increasing the amount of heat consumed for the latent heat of evaporation. In the present embodiment, the end portion of the water injection pipe 54 is connected to a portion of the horizontal portion 45 that is 0.2 to 3 m outward from the object to be supplied port 31.

The water supplied to the dehydrated cake via the water injection pipe 54 is stored in the tank 50. The water stored in the tank 50 is pumped into the water injection pipe 52 by a pump 51 such as a centrifugal pump or an axial flow pump. At the end of the water injection pipe 52, the start end of the water injection pipe 54, the start end of the water injection pipe (“second water injection pipe” in the claim) 55, and the water injection pipe (“third note” in the claim) are arranged in this order from the bottom. Water pipes ") 56 start ends are connected.

The water injection pipe 54 is provided with a pressure reducing valve 60 for adjusting the water pressure of the water flowing through the water injection pipe 54, a flow meter 61 for displaying the flow rate of the water flowing through the water injection pipe 54, and a water injection control means B in order from the start end. ing. The water injection control means B includes an adjustment valve (“first adjustment valve” in the claim) 62 for adjusting the flow rate of water flowing through the water injection pipe 54, and an on-off valve 63 for opening and closing the water injection pipe 54. By providing the on-off valve 63 on the downstream side of the adjusting valve 62, it is possible to prevent the on-off valve 63 from being operated to supply more water than necessary to the furnace body 10 when the adjusting valve 62 malfunctions. can do.

The water pressure of the water flowing through the water injection pipe 54 is adjusted by the pressure reducing valve 60 to 0.05 to 0.3 MPa from the internal pressure of the furnace body 10 during operation. As a result, it is possible to prevent the water flowing from the start end portion to the end portion of the water injection pipe 54 from flowing back.

The flow rate of water flowing through the water injection pipe 54, that is, the flow rate of water supplied to the dehydrated cake to increase the water content of the dehydrated cake is adjusted by the adjusting valve 62 to 2 to 10% by weight with respect to the supplied amount of the dehydrated cake. There is. Further, the temperature of the sand layer 20 of the furnace body 10 during operation is set to 700 to 750 ° C., and the temperature of the sand layer 20 is measured by a temperature sensor 64 such as a thermoelectric pair provided in the sand layer 20. As a result, when the temperature of the sand layer 20 of the furnace body 10 during operation rises to 705 ° C, which is 5 ° C higher than 700 ° C, the regulating valve 62 is operated to add 2% by weight of water to the dehydrated cake. The sand layer 20 can be cooled to 700 ° C., more specifically to 690 ° C. by increasing the amount of heat supplied and consumed for the latent heat of evaporation, and the temperature of the sand layer 20 of the furnace body 10 during operation is 5 more than 750 ° C. When the temperature rises to 755 ° C, which is higher than the temperature, the regulating valve 62 is operated to supply 10% by weight of water to the dehydrated cake to increase the amount of heat consumed for latent heat of evaporation and cool the sand layer 20 to 750 ° C. More specifically, it can be cooled to 740 ° C.

A first spray water supply port 32 for supplying water to be sprayed to the freeboard portion of the furnace body 10 is formed on the upper portion of the side wall 11 of the furnace body 10. Further, the water injection pipe 52 and the first spray water supply port 32 are connected by a water injection pipe 55, and the water injection pipe 55 is connected to a regulating valve that adjusts the flow rate of water flowing through the water injection pipe 55 (“second adjusting valve” in the claim. ") 65 is provided.

The temperature of the free board portion of the furnace body 10 during operation is set to 850 to 880 ° C., and the temperature of the free board is measured by a temperature sensor 66 provided near the lower side of the first spray water supply port 32. ing. The temperature sensor 66 is attached to a temperature sensor mounting seat (not shown) provided on the side wall 11 of the furnace body 10. A plurality of temperature sensors 64 may be installed at locations other than the vicinity below the first spray water supply port 32. In that case, by installing the temperature sensors 64 at different positions in the vertical direction of the furnace body 10, the free board may be installed. The temperature distribution in the vertical direction of the furnace body 10 can be measured.

A second spray water supply port 33 for supplying water to be sprayed to the discharge portion of the furnace body 10 is formed at the upper end of the side wall 11 of the furnace body 10. Further, the water injection pipe 52 and the second spray water supply port 33 are connected by a water injection pipe 56, and the water injection pipe 56 is connected to a regulating valve that adjusts the flow rate of water flowing through the water injection pipe 56 (“third adjusting valve” in the claim. ”) 67 is provided.

The upper wall 13 of the furnace body 10 is formed with a discharge port 34 for discharging the combustion exhaust gas generated when the dehydrated cake is burned to the outside. The temperature of the discharge portion of the furnace body 10 is measured by a temperature sensor 68 provided in the vicinity of the discharge port 34.

At the lower end of the side wall 11 of the furnace body 10, an auxiliary fuel supply device 36 such as a gas gun or an oil gun that heats the sand layer 20 when the furnace body 10 is started is provided. Further, the auxiliary fuel supply device 36 is supplied with auxiliary fuel such as city gas and heavy oil from the outside.

A heat recovery device 70 is provided on the downstream side of the combustion exhaust gas discharged from the furnace body 10 in the discharge direction, and an exhaust gas treatment device 71 is provided on the downstream side of the heat recovery device 70, and is downstream of the exhaust gas treatment device 71. A chimney 72 is provided on the side.

The heat recovery device 70 is an air preheater that exchanges heat between the combustion exhaust gas and the combustion air. In addition, a fuel air supply means for supplying combustion air to the heat recovery device is provided. Specifically, a supercharger or the like that drives a turbine by using a flow blower, an air preheater, or combustion exhaust gas discharged from a flow furnace to generate combustion air can be appropriately selected. In addition, a blower or the like that supplies combustion air to the auxiliary fuel supply device 36 at the time of starting is also provided. The exhaust gas treatment device 71 is composed of a dust collector that collects combustion ash and dust contained in the combustion exhaust gas, a smoke exhaust treatment tower that collects impurities contained in the combustion exhaust gas, and the like.

The discharge port 34 of the furnace body 10 and the heat recovery device 70 are connected by a pipe 81, the heat recovery device 70 and the exhaust gas treatment device 71 are connected by a pipe 82, and the exhaust gas treatment device 71 and the chimney 72 are connected by a pipe 83. ing. As a result, the high-temperature combustion exhaust gas discharged from the furnace body 10 is effectively used for heating the combustion air in the heat recovery device 70, and after impurities are captured by the exhaust gas treatment device 71, it is external from the chimney 72. Is discharged to.

<Controller>
Next, the controller 25 that controls the temperature of the furnace body 10 of the flow furnace will be described. As shown in FIG. 2, on the input side of the controller 25, a temperature sensor 64 for measuring the temperature of the sand layer 20 of the furnace body 10, a temperature sensor 66 for measuring the temperature of the free board portion of the furnace body 10, and the furnace body A temperature sensor 68 for measuring the temperature in the vicinity of the discharge port 34 of the 10 is connected via a predetermined input interface circuit.

On the other hand, on the output side of the controller 25, an adjusting valve 62 for adjusting the flow rate of water flowing through the water injection pipe 54, an on-off valve 63 for opening and closing the water injection pipe 54, and an adjustment for adjusting the flow rate of water flowing through the water injection pipe 55. A valve 65 and a regulating valve 67 for adjusting the flow rate of water flowing through the water injection pipe 56 are connected via a predetermined output interface circuit.

<Cooling method of sand layer>
Next, a cooling method when the temperature of the sand layer 20 of the furnace body 10 of the flow furnace becomes 5 ° C. higher than the set temperature of 700 to 750 ° C. will be described. In addition, in order to facilitate understanding, the case where the set temperature is 700 ° C. will be described as an example.

As shown in FIG. 3, in step S1, the controller 25 determines the temperature measured by the temperature sensor 64 (hereinafter, referred to as “first temperature” for convenience). If it is determined that the first temperature is higher than 705 ° C, the process proceeds to step S2. On the other hand, when it is determined that the first temperature is 695 to 705 ° C., step S1 is repeated.

In step S2, the controller 25 operates the on-off valve 63 in the opening direction, and proceeds to step S3.

In step S3, the controller 25 operates the adjusting valve 62 in the opening direction to open the adjusting valve 62 to the initial opening degree, and proceeds to step S4. The adjusting valve 62 can be adjusted in the range of 0 to 100% opening. When the opening is 0%, the adjusting valve 62 is closed, and when the opening is 100%, the adjusting valve 62 is fully opened. In the present embodiment, the initial opening degree is set to an opening degree of 20%.

The amount of water injected into the dehydrated cake is preferably an amount corresponding to 1 to 4% by weight with respect to the amount of water supplied per hour (kg / h) of the dehydrated cake. If the amount of water injected is less than 1% by weight, it is assumed that control will take time. On the other hand, if it is more than 4% by weight, the cooling effect is excellent, but there is a risk of causing a rapid temperature drop. As a result, water is injected into the dehydrated cake flowing through the pipe 42 to increase the water content of the dehydrated cake, and the amount of water that evaporates in the vicinity of the flowing portion 20A of the sand layer 20 is increased to increase the amount of heat consumed for the latent heat of vaporization of the sand layer 20. The temperature can be cooled. The organic matter contained in the dehydrated cake burns in the vicinity of the flowing portion 20A of the sand layer 20.

There is a correlation between the opening degree of the adjusting valve 62 and the water injection amount, and when the opening degree of the adjusting valve 62 is adjusted to 10 to 100%, the water injection amount is adjusted to 1 to 4% by weight. Thereby, the opening degree of the adjusting valve 62 can be adjusted to adjust the water injection amount to 1 to 4% by weight according to the first temperature, and the temperature of the sand layer 20 can be quickly cooled.

In step S4, the controller 25 operates the adjusting valve 65 to adjust the flow rate of water flowing through the water injection pipe 55 to a predetermined flow rate, and proceeds to step S5. As a result, water can be sprayed onto the freeboard portion from a water gun (not shown) connected to the supply port 32 of the furnace body 10 to cool the temperature of the freeboard portion. Note that step S4 is not an essential step and may be omitted.

In step S5, the controller 25 operates the adjusting valve 67 to adjust the flow rate of water flowing through the water injection pipe 56 to a predetermined flow rate, and proceeds to step S6. As a result, water is sprayed from the water gun (not shown) connected to the supply port 33 of the furnace body 10 to the discharge portion located at the upper part of the furnace body 10 to cool the temperature of the discharge portion. Note that step S5 is not an essential step and may be omitted.

In step S6, the controller 25 maintains the state of steps S3 to S5 described above for 10 to 3000 seconds, which is a predetermined time, and proceeds to step S7. As a result, the cooling effect of the amount of water injected into the dehydrated cake can be efficiently grasped.

In step S7, the controller 25 determines whether or not the temperature of the sand layer 20 is cooled by the amount of water injected into the dehydrated cake. In the present embodiment, the first temperature is compared with the temperature measured by the temperature sensor 64 in step S7 (hereinafter, referred to as “second temperature” for convenience).

When the second temperature is lower than the first temperature and it is determined that the temperature of the sand layer 20 is cooled by the amount of water injected into the dehydrated cake, the process proceeds to step S8. On the other hand, when the second temperature is higher than the first temperature and it is determined that the temperature of the sand layer 20 is not cooled by the amount of water injected into the dehydrated cake, the adjusting valve 62 is opened according to the second temperature. The temperature is further increased and the process proceeds to step S3. For example, when the second temperature is 705 to 710 ° C., the adjusting valve 62 is opened from an initial opening degree of 20% to an opening degree of 60% to change the water injection amount from 1.6% by weight to 3% by weight, and the second temperature is changed. In the case of 710 to 715 ° C., the adjusting valve 62 is opened from an initial opening degree of 20% to an opening degree of 100% to change the water injection amount from 1.6% by weight to 4% by weight. As a result, the temperature of the sand layer 20 can be quickly cooled by adjusting the amount of water injection according to the second temperature. The opening degree of the adjusting valve 62 can be adjusted continuously from the initial opening degree of 20% to the opening degree of 100% according to the second temperature, or can be opened stepwise every 5% of the opening degree. As a result, the opening degree of the regulating valve 62 can be adjusted to increase the amount of water injection according to the second temperature, and the temperature of the sand layer 20 can be efficiently cooled.

As a method of determining whether or not the temperature of the sand layer 20 is cooled by the amount of water injected into the dehydrated cake, instead of the method of comparing the first temperature and the second temperature, the set temperature is 700 ° C. It is possible to utilize the change in the temperature difference between the two temperatures and the change in the second temperature over time, that is, whether the second temperature increases with the passage of time.

In step S8, when the controller 25 determines that the temperature measured by the temperature sensor 64 (hereinafter, referred to as the third temperature for convenience) is within the cooling completion temperature of 690 to 700 ° C., the controller 25 proceeds to step 9. move on. On the other hand, when it is determined that the third temperature is within 700 to 705 ° C., which is the temperature at which cooling is not completed, the opening degree of the adjusting valve 62 is closed according to the third temperature, and the process proceeds to step S3. In this case, the opening degree of the adjusting valve 62 may be continuously opened from the initial opening degree of 20% to 10% according to the third temperature, or may be opened stepwise by 5% according to the third temperature. For example, when the third temperature is 705 ° C, the regulating valve 62 is maintained at an initial opening degree of 20% to make the water injection amount 1.6% by weight, and when the third temperature is 700 ° C, The adjusting valve 62 is closed from the initial opening degree of 20% to the opening degree of 10% to change the water injection amount from 1.6% by weight to 1.3% by weight. As a result, the temperature of the sand layer 20 can be slowly cooled by reducing the amount of water injection according to the third temperature.

In step S9, the controller 25 operates the adjusting valve 67 to adjust the flow rate of the water flowing through the water injection pipe 56 to stop water (0% by weight), and proceeds to step S10. Note that step S9 is not an essential step and may be omitted.

In step S10, the controller 25 operates the adjusting valve 65 to adjust the flow rate of the water flowing through the water injection pipe 55 to stop water (0% by weight), and proceeds to step S11. Note that step S10 is not an essential step and may be omitted.

In step S11, the controller 25 operates the adjusting valve 62 to adjust the flow rate of the water flowing through the water injection pipe 54 to stop water (0% by weight), and proceeds to step S12.

In step S12, the controller 25 operates the on-off valve 63 to close the on-off valve 63 provided on the downstream side of the adjusting valve 62. As a result, even if there is an unnecessary water flow due to a failure of the regulating valve 62 or the like, the water flow can be blocked by the on-off valve 63.

In the present embodiment, the water injection control means B is composed of a regulating valve 62 and an on-off valve 63, and has a function of adjusting the flow rate of water in the regulating valve 62, starting of water supply of the on-off valve 63, and It is also possible to use one valve that has the function of stopping. When one valve is used, steps S2 and S12 of FIG. 3 can be omitted, and the sand layer 20 can be cooled by the controller 25 with simple control.

Further, in the present embodiment, the distribution pipe 21 for supplying the combustion air to the lower part of the flow furnace is provided as the combustion air supply means A, but a dispersion plate having a large number of openings for horizontally dividing the lower part of the flow furnace is installed. However, it is also possible to adopt a configuration in which combustion air is supplied from below the dispersion plate.

The present invention can be applied to a flow furnace used in a pressurized flow furnace and a flow furnace used in a normal pressure flow furnace.

10 Furnace 11 Side wall 20 Sand layer 21 Dispersion pipe 42 Piping 54 Water injection pipe (first water injection pipe)
55 Water injection pipe (second water injection pipe)
56 Water injection pipe (3rd water injection pipe)
62 Adjusting valve (1st adjusting valve)
63 On-off valve 64 Temperature sensor 65 Adjusting valve (second adjusting valve)
67 Adjusting valve (3rd adjusting valve)
A Combustion air supply means B Water injection control means

The present invention relates to a flow furnace and a cooling method thereof. A flow furnace provided with a means for injecting water for cooling the flow medium into an object to be treated such as sewage sludge, and an object to be treated are injected according to the temperature of the flow medium. It relates to a cooling method for adjusting the flow rate of water.

In the conventional flow furnace, a water gun is provided above the freeboard part of the flow furnace, and when the temperature of the freeboard part of the flow furnace becomes higher than a predetermined temperature, the freeboard part is connected via the water gun. The technique of spraying water is known. (See Patent Document 1)
Further, a nozzle is provided near the upper part of the flow medium of the flow furnace, and when the temperature of the flow medium of the flow furnace becomes higher than a predetermined temperature, water is directly supplied to the flow medium through the nozzle. The technology to do is known. (See Patent Document 2)

Japanese Unexamined Patent Publication No. 2005-274025 Japanese Unexamined Patent Publication No. 9-236233

However, in the technique of Patent Document 1, the water sprayed from the water gun to the free board portion reaches the vicinity of the flow medium provided in the lower part of the flow furnace by convection flowing from the lower part to the upper part of the flow furnace. Since this is not possible, there is a risk that the flow medium having become higher than the predetermined temperature cannot be sufficiently cooled.

Further, in the technique of Patent Document 2, the water supplied from the nozzle comes into direct contact with the fluid medium and rapidly cools the fluid medium having a temperature higher than a predetermined temperature, so that the fluid medium cracks and the fluid medium becomes cracked. Since the particle size becomes smaller, the amount of the flow medium discharged from the flow furnace along with the combustion exhaust gas may increase. As a result, the amount of the flow medium in the flow furnace is reduced, so that it is expected that the running cost will increase, such as the increase in the flow medium to be replenished and the collection and processing of the accompanying flow medium.

Therefore, the present invention proposes a flow furnace provided with a means for injecting water for cooling the flow medium into a pipe for supplying an object to be processed in the flow furnace, and a method for injecting water for cooling the flow medium.

The present invention and the effects of action that have solved the above problems are as follows.
In the first invention, a sand layer is provided in the lower part of the furnace body, a combustion air supply means for supplying combustion air into the sand layer is provided, and a temperature sensor for measuring the temperature of the sand layer is inserted in the side wall of the furnace body. In a flow furnace in which a pipe for supplying an object to be processed is connected to the side wall of the furnace body.
The end of the first water injection pipe that injects water into the object to be treated to increase the water content of the object to be treated is connected to the pipe, and the first water injection pipe is based on the measurement result of the temperature sensor. The water injection control means is provided , and the water injection control means includes a first adjusting valve for adjusting the flow rate of water and an on-off valve for starting and stopping the supply of water .

(Action effect)
Since the end of the first water injection pipe that supplies water to the object to be treated is connected to the pipe and a water injection control means that drives based on the measurement result of the temperature sensor is provided, water is supplied to the object to be processed according to the sand layer temperature. By supplying water to increase the water content of the object to be treated and increasing the amount of heat consumed by the latent heat of evaporation, the sand layer can be cooled and the flow furnace can be operated stably.

Further, since the water injection control means includes a first adjusting valve for adjusting the flow rate of water and an on-off valve for starting and stopping the supply of water, the on-off valve is driven even when the first adjusting valve malfunctions. It is possible to prevent unnecessary water from being supplied to the furnace body.

The second invention is characterized in that, in the configuration of the first invention, the end portion of the first water injection pipe is connected to the end portion of the pipe.

(Action effect)
Since the end of the first water injection pipe is connected to the part of the pipe near the side wall of the furnace body, the effect of pressure loss is reduced and the object to be treated with a high water content is supplied to the furnace body at a stable pace. can do.

The third invention is characterized in that, in the configuration of the first or second invention, the end portion of the pipe is connected to a portion of the side wall that is biased downward from the middle in the vertical direction.

(Action effect)
Since the end of the first water injection pipe was connected to a portion of the side wall that was biased below the middle in the vertical direction, a large amount of water contained in the object to be treated evaporates near the flow part of the sand layer. It is possible to prevent damage to the sand layer.

In the fourth invention, a sand layer is provided in the lower part of the furnace body, a supply pipe for supplying combustion air is inserted in the sand layer, and a temperature sensor for measuring the temperature of the sand layer is inserted in the upper part of the sand layer. In the cooling method of a flow furnace in which a pipe for supplying an object to be processed is connected to the side wall of the body,
A first regulating valve that connects the end of the first water injection pipe that supplies water to the object to be treated to the pipe and adjusts the flow rate of water to the first water injection pipe, and an on- off valve that starts and stops the supply of water. Provided
If the temperature of the sand layer is higher than the predetermined set temperature, after the first water injection pipe was opened by driving the on-off valve, water predetermined flowing through the first water injection pipe by driving the first adjusting valve Adjust to the flow rate,
When the temperature of the sand layer becomes lower than a predetermined set temperature, the first regulating valve is driven to stop the water flowing through the first water injection pipe, and then the on-off valve is driven to perform the first note. the water tube, wherein the closed Jill.

(Action effect)
Connect the end of the first water injection pipe for supplying water to be treated in the pipe, a first regulator valve for regulating the flow rate of water to the first water injection tube, the open valve closing is provided, the temperature of the sand layer is given If the temperature is higher than the set temperature, the on-off valve is driven to open the first water injection pipe , and then the first regulating valve is driven to adjust the water flowing through the first water injection pipe to a predetermined flow rate, and the temperature of the sand layer rises. When the temperature becomes lower than the predetermined set temperature, the first regulating valve is driven to stop the water flowing through the first water injection pipe, and then the on-off valve is driven to close the first water injection pipe, so that the sand layer is formed. When the temperature rises above a predetermined set temperature, water is supplied to the object to be treated to increase the water content of the object to be treated, the amount of heat consumed by latent heat of evaporation is increased, and the sand layer is cooled to cool the flow furnace. Can be operated stably. Further, even if the first regulating valve malfunctions, the on-off valve can be driven to prevent unnecessary water from being supplied to the furnace body.

The fifth invention is characterized in that, in the configuration of the fourth invention, the first regulating valve is driven to increase or decrease the flow rate of water flowing through the first water injection pipe according to the temperature of the sand layer.

(Action effect)
Since the first regulating valve is driven to increase or decrease the flow rate of water flowing through the first water injection pipe according to the temperature of the sand layer, the water content of the water contained in the object to be treated is increased or decreased, and the amount of heat consumed by the latent heat of vaporization is increased or decreased. Therefore, the sand layer can be cooled quickly and the flow furnace can be operated stably.

In the sixth aspect of the invention, in the configuration of the fourth or fifth invention, the end portion of the second water injection pipe that supplies water to be sprayed to the free board portion is connected to the upper part of the side wall of the furnace body, and water is connected to the second water injection pipe. A second regulating valve is provided to adjust the flow rate of
After the first water injection pipe was opened by driving the on-off valve, and adjusting the water flowing through the second water supply pipe by driving the second control valve to a predetermined flow rate.

(Action effect)
The end of the second water injection pipe that supplies water to be sprayed to the free board is connected to the upper part of the side wall of the furnace body, the second water injection pipe is provided with a second adjustment valve that adjusts the flow rate of water, and the on-off valve is driven. After opening the first water injection pipe , the second regulating valve is driven to adjust the water flowing through the second water injection pipe to a predetermined flow rate, so that the free board part of the furnace body is cooled to make the flow furnace more responsive. It can be operated stably.

In the seventh aspect of the invention, in the configuration of any one of the fourth to sixth aspects, the terminal portion of the third water injection pipe that supplies water to be sprayed to the discharge portion is connected to the upper end portion of the side wall of the furnace body. A third regulating valve for adjusting the flow rate of water is provided in the third water injection pipe.
After the first water injection pipe was opened by driving the on-off valve, or, after adjusting the water flowing through the second water supply pipe by driving the second control valve to a predetermined flow rate, driving the third adjustment valve The water flowing through the third water injection pipe is adjusted to a predetermined flow rate.

(Action effect)
The end of the third water injection pipe that supplies water to be sprayed to the discharge part is connected to the upper end of the side wall of the furnace body, and the third water injection pipe is provided with a third adjustment valve that adjusts the flow rate of water.
After driving the on-off valve to open the first water injection pipe , or driving the second regulating valve to adjust the water flowing through the second water injection pipe to a predetermined flow rate, the third regulating valve is driven to the third. 3 Since the water flowing through the water injection pipe is adjusted to a predetermined flow rate, the discharge portion of the furnace body can be cooled and the flow furnace can be operated more stably.

By increasing the water content of the water contained in the object to be treated and increasing the amount of heat consumed by the latent heat of vaporization, the sand layer that has become higher than the predetermined set temperature can be cooled, and the flow furnace can be operated stably. ..

It is explanatory drawing of the flow furnace. It is a connection diagram of a controller. It is explanatory drawing of the cooling method of a flow medium.

As shown in FIG. 1, the furnace body 10 of the flow furnace has a side wall 11 formed in a cylindrical shape, a lower wall 12 formed so as to project downward, and an upper wall 12 formed so as to project upward. It is formed from the wall 13.

A sand layer 20 serving as a flow medium formed of sand or the like having a certain particle size or more is provided in the lower part of the furnace body 10. In the sand layer 20, a dispersion pipe 21 having a large number of discharge ports for supplying combustion air is arranged as the combustion air supply means A. As a result, when the flow furnace is in operation, that is, when a predetermined amount of dehydrated cake to be processed is supplied to the furnace body 10 and the dehydrated cake is burned in the furnace body 10, the sand layer is formed from the dispersion pipe 21. The combustion air supplied to the 20 20 causes the sand or the like located above the sand layer 20 to flow upward. In the present specification, a portion that flows upward during operation of the flow furnace is referred to as a flow portion 20A, a portion other than that is referred to as a non-fluid portion 20B, and both are collectively referred to as a sand layer 20.
A temperature sensor mounting seat (not shown) for inserting a temperature sensor 64 for measuring the temperature of the sand layer 20 into the furnace is provided on the side wall 11 of the furnace body 10, and the temperature sensor 64 is mounted. The number of temperature sensors 64 may be plurality, and in that case, the temperature distribution of the sand layer 20 in the vertical direction can be measured by installing the temperature sensors 64 at different positions in the vertical direction of the furnace body 10.

The starting end of the dispersion pipe 21 is connected to a combustion air supply port 30 formed in the lower part of the side wall 11 of the furnace body 10. Further, the combustion air supply port 30 of the furnace body 10 and the heat recovery device 70 are connected by a pipe 80. In the heat recovery device 70, the combustion air is heated by the combustion exhaust gas exhausted from the furnace body 10 to the outside, and the temperature of the combustion air flowing through the pipe 80 is maintained above a certain level. As a result, combustion air having a certain temperature or higher can be supplied to the sand layer 20, and the dehydrated cake can be efficiently burned in the furnace body 10. Further, the latent heat of the combustion exhaust gas exhausted from the furnace body 10 to the outside can be efficiently used.

A dehydrated cake, which is an example of an object to be treated, is located in a portion of the side wall 11 of the furnace body 10 that is biased downward from the middle in the vertical direction and is located above the flow portion 20A of the sand layer 20. The object to be processed supply port 31 is formed. The dehydrated cake is an organic waste whose water content is adjusted to 72 to 80% by mass by dehydrating sewage sludge, human waste, etc. containing an organic substance and having a water content of 97 to 98% by mass.

The dehydrated cake supplied to the furnace body 10 from the object to be processed supply port 31 falls between the upper end of the flowing portion 20A and the upper end of the non-flowing portion 20B of the sand layer 20, and the water contained in the dehydrated cake is removed. When it evaporates, it takes away the heat of the flow part 20A at the time of evaporation, acts in the direction of lowering the temperature of the flow part 20A, and the organic matter contained in the dehydrated cake burns to raise the temperature of the free board part of the furnace body 10. Acts on. As a result, when the dehydrated cake is supplied to the furnace body 10, the temperature of the sand layer 20 and the temperature of the freeboard portion can be maintained at the set temperatures, and the flow furnace can be operated stably.

The furnace body 10 shown in FIG. 1 has a height of 12000 mm and an inner diameter of 500 to 9000 mm, the height of the sand layer 20 when not flowing is 3500 mm, and the object supply port 31 to be processed has a height of 5000 mm of the furnace body 10. It is formed at a height of 1500 mm from the sand layer 20 when it is not flowing. The position of the object to be processed supply port 31 varies depending on the flow rate of the combustion exhaust gas supplied from the dispersion pipe 21, but is located at a height of 30 to 50% of the height of the sand layer 20 at the time of non-flow. As a result, the fluctuation of the furnace body 10 can be suppressed and the flow furnace can be operated stably.

The dehydrated cake is stored in the storage tank 40. The discharge port 41 of the storage tank 40 and the supply port 31 of the furnace body 10 are connected by a pipe 42. The pipe 42 has a horizontal portion 43 extending from the discharge port 41 of the storage tank 40 toward the furnace body 10, a vertical portion 44 extending upward from the terminal portion of the horizontal portion 43, and a terminal of the vertical portion 44. It is formed from a horizontal portion 45 extending from the portion toward the object supply port 31 of the furnace body 10. Further, a pump (not shown) selected from a uniaxial screw type pump, a piston pump and the like is provided in the lower part of the storage tank 40. As a result, a certain amount of dehydrated cake can be supplied to the furnace body 10 via the pipe 42, and the dehydrated cake can be stably burned in the furnace body 10.

The end of the water injection pipe (“first water injection pipe” in the claim) 54 that supplies water to the dehydrated cake is connected to the pipe 42. Although the end portion of the water injection pipe 54 can be connected to either the horizontal portion 43 or the vertical portion 44, it is preferable to connect the end portion of the water injection pipe 54 to the horizontal portion 45 in order to reduce the influence of pressure loss. .. Further, in order to further reduce the influence of pressure loss in the horizontal portion 45, it is more preferable to connect the end portion of the water injection pipe 54 to a portion of the horizontal portion 45 close to the object to be supplied port 31. As a result, when the temperature of the sand layer 20 rises above the set temperature, water is supplied to the dehydrated cake via the water injection pipe 54 to increase the water content of the dehydrated cake, and the vicinity of the flowing portion 20A of the sand layer 20. The sand layer 20 can be cooled by increasing the amount of water that evaporates in the water and increasing the amount of heat consumed for the latent heat of evaporation. In the present embodiment, the end portion of the water injection pipe 54 is connected to a portion of the horizontal portion 45 that is 0.2 to 3 m outward from the object to be supplied port 31.

The water supplied to the dehydrated cake via the water injection pipe 54 is stored in the tank 50. The water stored in the tank 50 is pumped into the water injection pipe 52 by a pump 51 such as a centrifugal pump or an axial flow pump. At the end of the water injection pipe 52, the start end of the water injection pipe 54, the start end of the water injection pipe (“second water injection pipe” in the claim) 55, and the water injection pipe (“third note” in the claim) are arranged in this order from the bottom. Water pipes ") 56 start ends are connected.

The water injection pipe 54 is provided with a pressure reducing valve 60 for adjusting the water pressure of the water flowing through the water injection pipe 54, a flow meter 61 for displaying the flow rate of the water flowing through the water injection pipe 54, and a water injection control means B in order from the start end. ing. The water injection control means B includes an adjustment valve (“first adjustment valve” in the claim) 62 for adjusting the flow rate of water flowing through the water injection pipe 54, and an on-off valve 63 for opening and closing the water injection pipe 54. By providing the on-off valve 63 on the downstream side of the adjusting valve 62, it is possible to prevent the on-off valve 63 from being operated to supply more water than necessary to the furnace body 10 when the adjusting valve 62 malfunctions. can do.

The water pressure of the water flowing through the water injection pipe 54 is adjusted by the pressure reducing valve 60 to 0.05 to 0.3 MPa from the internal pressure of the furnace body 10 during operation. As a result, it is possible to prevent the water flowing from the start end portion to the end portion of the water injection pipe 54 from flowing back.

The flow rate of water flowing through the water injection pipe 54, that is, the flow rate of water supplied to the dehydrated cake to increase the water content of the dehydrated cake is adjusted by the adjusting valve 62 to 2 to 10% by weight with respect to the supplied amount of the dehydrated cake. There is. Further, the temperature of the sand layer 20 of the furnace body 10 during operation is set to 700 to 750 ° C., and the temperature of the sand layer 20 is measured by a temperature sensor 64 such as a thermoelectric pair provided in the sand layer 20. As a result, when the temperature of the sand layer 20 of the furnace body 10 during operation rises to 705 ° C, which is 5 ° C higher than 700 ° C, the regulating valve 62 is operated to add 2% by weight of water to the dehydrated cake. The sand layer 20 can be cooled to 700 ° C., more specifically to 690 ° C. by increasing the amount of heat supplied and consumed for the latent heat of evaporation, and the temperature of the sand layer 20 of the furnace body 10 during operation is 5 more than 750 ° C. When the temperature rises to 755 ° C, which is higher than the temperature, the regulating valve 62 is operated to supply 10% by weight of water to the dehydrated cake to increase the amount of heat consumed for latent heat of evaporation and cool the sand layer 20 to 750 ° C. More specifically, it can be cooled to 740 ° C.

A first spray water supply port 32 for supplying water to be sprayed to the freeboard portion of the furnace body 10 is formed on the upper portion of the side wall 11 of the furnace body 10. Further, the water injection pipe 52 and the first spray water supply port 32 are connected by a water injection pipe 55, and the water injection pipe 55 is connected to a regulating valve that adjusts the flow rate of water flowing through the water injection pipe 55 (“second adjusting valve” in the claim. ") 65 is provided.

The temperature of the free board portion of the furnace body 10 during operation is set to 850 to 880 ° C., and the temperature of the free board is measured by a temperature sensor 66 provided near the lower side of the first spray water supply port 32. ing. The temperature sensor 66 is attached to a temperature sensor mounting seat (not shown) provided on the side wall 11 of the furnace body 10. A plurality of temperature sensors 64 may be installed at locations other than the vicinity below the first spray water supply port 32. In that case, by installing the temperature sensors 64 at different positions in the vertical direction of the furnace body 10, the free board may be installed. The temperature distribution in the vertical direction of the furnace body 10 can be measured.

A second spray water supply port 33 for supplying water to be sprayed to the discharge portion of the furnace body 10 is formed at the upper end of the side wall 11 of the furnace body 10. Further, the water injection pipe 52 and the second spray water supply port 33 are connected by a water injection pipe 56, and the water injection pipe 56 is connected to a regulating valve that adjusts the flow rate of water flowing through the water injection pipe 56 (“third adjusting valve” in the claim. ”) 67 is provided.

The upper wall 13 of the furnace body 10 is formed with a discharge port 34 for discharging the combustion exhaust gas generated when the dehydrated cake is burned to the outside. The temperature of the discharge portion of the furnace body 10 is measured by a temperature sensor 68 provided in the vicinity of the discharge port 34.

At the lower end of the side wall 11 of the furnace body 10, an auxiliary fuel supply device 36 such as a gas gun or an oil gun that heats the sand layer 20 when the furnace body 10 is started is provided. Further, the auxiliary fuel supply device 36 is supplied with auxiliary fuel such as city gas and heavy oil from the outside.

A heat recovery device 70 is provided on the downstream side of the combustion exhaust gas discharged from the furnace body 10 in the discharge direction, and an exhaust gas treatment device 71 is provided on the downstream side of the heat recovery device 70, and is downstream of the exhaust gas treatment device 71. A chimney 72 is provided on the side.

The heat recovery device 70 is an air preheater that exchanges heat between the combustion exhaust gas and the combustion air. In addition, a fuel air supply means for supplying combustion air to the heat recovery device is provided. Specifically, a supercharger or the like that drives a turbine by using a flow blower, an air preheater, or combustion exhaust gas discharged from a flow furnace to generate combustion air can be appropriately selected. In addition, a blower or the like that supplies combustion air to the auxiliary fuel supply device 36 at the time of starting is also provided. The exhaust gas treatment device 71 is composed of a dust collector that collects combustion ash and dust contained in the combustion exhaust gas, a smoke exhaust treatment tower that collects impurities contained in the combustion exhaust gas, and the like.

The discharge port 34 of the furnace body 10 and the heat recovery device 70 are connected by a pipe 81, the heat recovery device 70 and the exhaust gas treatment device 71 are connected by a pipe 82, and the exhaust gas treatment device 71 and the chimney 72 are connected by a pipe 83. ing. As a result, the high-temperature combustion exhaust gas discharged from the furnace body 10 is effectively used for heating the combustion air in the heat recovery device 70, and after impurities are captured by the exhaust gas treatment device 71, it is external from the chimney 72. Is discharged to.

<Controller>
Next, the controller 25 that controls the temperature of the furnace body 10 of the flow furnace will be described. As shown in FIG. 2, on the input side of the controller 25, a temperature sensor 64 for measuring the temperature of the sand layer 20 of the furnace body 10, a temperature sensor 66 for measuring the temperature of the free board portion of the furnace body 10, and the furnace body A temperature sensor 68 for measuring the temperature in the vicinity of the discharge port 34 of the 10 is connected via a predetermined input interface circuit.

On the other hand, on the output side of the controller 25, an adjusting valve 62 for adjusting the flow rate of water flowing through the water injection pipe 54, an on-off valve 63 for opening and closing the water injection pipe 54, and an adjustment for adjusting the flow rate of water flowing through the water injection pipe 55. A valve 65 and a regulating valve 67 for adjusting the flow rate of water flowing through the water injection pipe 56 are connected via a predetermined output interface circuit.

<Cooling method of sand layer>
Next, a cooling method when the temperature of the sand layer 20 of the furnace body 10 of the flow furnace becomes 5 ° C. higher than the set temperature of 700 to 750 ° C. will be described. In addition, in order to facilitate understanding, the case where the set temperature is 700 ° C. will be described as an example.

As shown in FIG. 3, in step S1, the controller 25 determines the temperature measured by the temperature sensor 64 (hereinafter, referred to as “first temperature” for convenience). If it is determined that the first temperature is higher than 705 ° C, the process proceeds to step S2. On the other hand, when it is determined that the first temperature is 695 to 705 ° C., step S1 is repeated.

In step S2, the controller 25 operates the on-off valve 63 in the opening direction, and proceeds to step S3.

In step S3, the controller 25 operates the adjusting valve 62 in the opening direction to open the adjusting valve 62 to the initial opening degree, and proceeds to step S4. The adjusting valve 62 can be adjusted in the range of 0 to 100% opening. When the opening is 0%, the adjusting valve 62 is closed, and when the opening is 100%, the adjusting valve 62 is fully opened. In the present embodiment, the initial opening degree is set to an opening degree of 20%.

The amount of water injected into the dehydrated cake is preferably an amount corresponding to 1 to 4% by weight with respect to the amount of water supplied per hour (kg / h) of the dehydrated cake. If the amount of water injected is less than 1% by weight, it is assumed that control will take time. On the other hand, if it is more than 4% by weight, the cooling effect is excellent, but there is a risk of causing a rapid temperature drop. As a result, water is injected into the dehydrated cake flowing through the pipe 42 to increase the water content of the dehydrated cake, and the amount of water that evaporates in the vicinity of the flowing portion 20A of the sand layer 20 is increased to increase the amount of heat consumed for latent heat of vaporization of the sand layer 20. The temperature can be cooled. The organic matter contained in the dehydrated cake burns in the vicinity of the flowing portion 20A of the sand layer 20.

There is a correlation between the opening degree of the adjusting valve 62 and the water injection amount, and when the opening degree of the adjusting valve 62 is adjusted to 10 to 100%, the water injection amount is adjusted to 1 to 4% by weight. Thereby, the opening degree of the adjusting valve 62 can be adjusted to adjust the water injection amount to 1 to 4% by weight according to the first temperature, and the temperature of the sand layer 20 can be quickly cooled.

In step S4, the controller 25 operates the adjusting valve 65 to adjust the flow rate of water flowing through the water injection pipe 55 to a predetermined flow rate, and proceeds to step S5. As a result, water can be sprayed onto the freeboard portion from a water gun (not shown) connected to the supply port 32 of the furnace body 10 to cool the temperature of the freeboard portion. Note that step S4 is not an essential step and may be omitted.

In step S5, the controller 25 operates the adjusting valve 67 to adjust the flow rate of water flowing through the water injection pipe 56 to a predetermined flow rate, and proceeds to step S6. As a result, water is sprayed from the water gun (not shown) connected to the supply port 33 of the furnace body 10 to the discharge portion located at the upper part of the furnace body 10 to cool the temperature of the discharge portion. Note that step S5 is not an essential step and may be omitted.

In step S6, the controller 25 maintains the state of steps S3 to S5 described above for 10 to 3000 seconds, which is a predetermined time, and proceeds to step S7. As a result, the cooling effect of the amount of water injected into the dehydrated cake can be efficiently grasped.

In step S7, the controller 25 determines whether or not the temperature of the sand layer 20 is cooled by the amount of water injected into the dehydrated cake. In the present embodiment, the first temperature is compared with the temperature measured by the temperature sensor 64 in step S7 (hereinafter, referred to as “second temperature” for convenience).

When the second temperature is lower than the first temperature and it is determined that the temperature of the sand layer 20 is cooled by the amount of water injected into the dehydrated cake, the process proceeds to step S8. On the other hand, when the second temperature is higher than the first temperature and it is determined that the temperature of the sand layer 20 is not cooled by the amount of water injected into the dehydrated cake, the adjusting valve 62 is opened according to the second temperature. The temperature is further increased and the process proceeds to step S3. For example, when the second temperature is 705 to 710 ° C., the adjusting valve 62 is opened from an initial opening degree of 20% to an opening degree of 60% to change the water injection amount from 1.6% by weight to 3% by weight, and the second temperature is changed. In the case of 710 to 715 ° C., the adjusting valve 62 is opened from an initial opening degree of 20% to an opening degree of 100% to change the water injection amount from 1.6% by weight to 4% by weight. As a result, the temperature of the sand layer 20 can be quickly cooled by adjusting the amount of water injection according to the second temperature. The opening degree of the adjusting valve 62 can be adjusted continuously from the initial opening degree of 20% to the opening degree of 100% according to the second temperature, or can be opened stepwise every 5% of the opening degree. As a result, the opening degree of the regulating valve 62 can be adjusted to increase the amount of water injection according to the second temperature, and the temperature of the sand layer 20 can be efficiently cooled.

As a method of determining whether or not the temperature of the sand layer 20 is cooled by the amount of water injected into the dehydrated cake, instead of the method of comparing the first temperature and the second temperature, the set temperature is 700 ° C. It is possible to utilize the change in the temperature difference between the two temperatures and the change in the second temperature over time, that is, whether the second temperature increases with the passage of time.

In step S8, when the controller 25 determines that the temperature measured by the temperature sensor 64 (hereinafter, referred to as the third temperature for convenience) is within the cooling completion temperature of 690 to 700 ° C., the controller 25 proceeds to step 9. move on. On the other hand, when it is determined that the third temperature is within 700 to 705 ° C., which is the temperature at which cooling is not completed, the opening degree of the adjusting valve 62 is closed according to the third temperature, and the process proceeds to step S3. In this case, the opening degree of the adjusting valve 62 may be continuously opened from the initial opening degree of 20% to 10% according to the third temperature, or may be opened stepwise by 5% according to the third temperature. For example, when the third temperature is 705 ° C, the regulating valve 62 is maintained at an initial opening degree of 20% to make the water injection amount 1.6% by weight, and when the third temperature is 700 ° C, The adjusting valve 62 is closed from the initial opening degree of 20% to the opening degree of 10% to change the water injection amount from 1.6% by weight to 1.3% by weight. As a result, the temperature of the sand layer 20 can be slowly cooled by reducing the amount of water injection according to the third temperature.

In step S9, the controller 25 operates the adjusting valve 67 to adjust the flow rate of the water flowing through the water injection pipe 56 to stop water (0% by weight), and proceeds to step S10. Note that step S9 is not an essential step and may be omitted.

In step S10, the controller 25 operates the adjusting valve 65 to adjust the flow rate of the water flowing through the water injection pipe 55 to stop water (0% by weight), and proceeds to step S11. Note that step S10 is not an essential step and may be omitted.

In step S11, the controller 25 operates the adjusting valve 62 to adjust the flow rate of the water flowing through the water injection pipe 54 to stop water (0% by weight), and proceeds to step S12.

In step S12, the controller 25 operates the on-off valve 63 to close the on-off valve 63 provided on the downstream side of the adjusting valve 62. As a result, even if there is an unnecessary water flow due to a failure of the regulating valve 62 or the like, the water flow can be blocked by the on-off valve 63.

In the present embodiment, the water injection control means B is composed of a regulating valve 62 and an on-off valve 63, and has a function of adjusting the flow rate of water in the regulating valve 62, starting of water supply of the on-off valve 63, and It is also possible to use one valve that has the function of stopping. When one valve is used, steps S2 and S12 of FIG. 3 can be omitted, and the sand layer 20 can be cooled by the controller 25 with simple control.

Further, in the present embodiment, the distribution pipe 21 for supplying the combustion air to the lower part of the flow furnace is provided as the combustion air supply means A, but a dispersion plate having a large number of openings for horizontally dividing the lower part of the flow furnace is installed. However, it is also possible to adopt a configuration in which combustion air is supplied from below the dispersion plate.

The present invention can be applied to a flow furnace used in a pressurized flow furnace and a flow furnace used in a normal pressure flow furnace.

10 Furnace 11 Side wall 20 Sand layer 21 Dispersion pipe 42 Piping 54 Water injection pipe (first water injection pipe)
55 Water injection pipe (second water injection pipe)
56 Water injection pipe (3rd water injection pipe)
62 Adjusting valve (1st adjusting valve)
63 On-off valve 64 Temperature sensor 65 Adjusting valve (second adjusting valve)
67 Adjusting valve (3rd adjusting valve)
A Combustion air supply means B Water injection control means

Claims (8)

A sand layer is provided in the lower part of the furnace body, and a combustion air supply means for supplying combustion air into the sand layer is provided. A temperature sensor for measuring the temperature of the sand layer is inserted in the side wall of the furnace body, and the side wall of the furnace body is provided. In a flow furnace connected to a pipe that supplies the object to be processed
The end portion of the first water injection pipe that supplies water to the object to be treated in the pipe is connected, and the first water injection pipe is provided with a water injection control means that drives based on the measurement result of the temperature sensor. Characterized flow furnace. The flow furnace according to claim 1, wherein the water injection control means includes a first regulating valve for adjusting the flow rate of water and an on-off valve for starting and stopping the supply of water. The flow furnace according to claim 1 or 2, wherein the end portion of the first water injection pipe is connected to a portion of the pipe close to the side wall of the furnace body. The flow furnace according to any one of claims 1 to 3, wherein the end portion of the first water injection pipe is connected to a portion of the side wall that is biased downward from the middle in the vertical direction. A sand layer is provided in the lower part of the furnace body, a supply pipe for supplying combustion air is inserted in the sand layer, a temperature sensor for measuring the temperature of the sand layer is inserted in the upper part of the sand layer, and the side wall of the furnace body is covered. In the cooling method of the flow furnace connected to the piping that supplies the processed material,
A first adjusting valve that connects the end of the first water injection pipe that supplies water to the object to be treated to the pipe and adjusts the flow rate of water to the first water injection pipe, and opens and closes on the downstream side of the first adjustment valve. Provide a valve,
When the temperature of the sand layer is higher than a predetermined set temperature, the on-off valve is driven to open a portion of the first water injection pipe on the downstream side of the first regulating valve, and then the first regulating valve is driven. Adjust the water flowing through the first water injection pipe to the specified flow rate,
When the temperature of the sand layer becomes lower than a predetermined set temperature, the first regulating valve is driven to stop the water flowing through the first water injection pipe, and then the on-off valve is driven to perform the first note. A method for cooling a flow furnace, which comprises closing a portion of the water pipe on the downstream side of the first regulating valve. The cooling method for a flow furnace according to claim 5, wherein the first regulating valve is driven to increase or decrease the flow rate of water flowing through the first water injection pipe according to the temperature of the sand layer. A second regulating valve for adjusting the flow rate of water is provided in the second water injection pipe by connecting the end of the second water injection pipe that supplies water to be sprayed to the freeboard portion to the upper part of the side wall of the furnace body.
A claim for driving the on-off valve to open a portion of the first water injection pipe on the downstream side of the first regulating valve and then driving the second regulating valve to adjust the water flowing through the second water injection pipe to a predetermined flow rate. Item 5. The method for cooling a flow furnace according to item 5 or 6. A third regulating valve for adjusting the flow rate of water is provided in the third water injection pipe by connecting the end of the third water injection pipe that supplies water to be sprayed to the discharge portion to the upper end of the side wall of the furnace body.
After driving the on-off valve to open the downstream part of the first regulating valve in the first water injection pipe, or driving the second regulating valve to adjust the water flowing through the second water injection pipe to a predetermined flow rate. The cooling method for a flow furnace according to any one of claims 5 to 7, wherein the third adjusting valve is driven to adjust the water flowing through the third water injection pipe to a predetermined flow rate.

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