JP2002267119A - Furnace performance testing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a furnace performance testing method capable of obtaining performance testing data having reproducibility and high reliability. SOLUTION: The furnace performance testing method contains a process wherein wet pulp having a specified moisture content is incinerated in a furnace. The wet pulp is decreased in a heat generating amount by wetness and when its heat generating amount is reduced to a value approximately equal to that of a wet combustible substance and the wet pulp forms a substitution incinerating material. By preparing the wet pulp such that it has a specified moisture content, a substitution incineration material having a specified heat generating amount corresponding to a given content can be obtained any number of times without selecting a timing and a place.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for testing the performance of a furnace for incinerating wet combustibles such as sludge.

[0002]

2. Description of the Related Art Conventionally, incinerators such as fluidized bed furnaces and stalker furnaces have been used to incinerate water-containing combustible materials such as sludge and food waste. Such incinerators are generally designed based on empirical values in accordance with specifications such as the load of hydrated combustibles to be incinerated, so that the completed incinerator actually has the incineration capacity as specified. It is desired to carry out a furnace performance test to check in advance whether or not the furnace is operating.

[0003]

The flammable water-containing combustibles such as sludge are non-uniform, even if they are of the same type, having different components and different water contents depending on the place where they are discharged, season, time, and the like. For this reason, even if this is burned in a furnace, the calorific value is not constant, so that reproducible performance test data cannot be obtained. Test that compares the differences in
It has been difficult to perform tests and the like for furnace design and improvement using a test furnace.

[0004] In general, since flammable hydrates have a considerably lower calorific value than non-flammable hydrates, the reliability is high even if the flammable hydrate is burned in a furnace for incineration of flammable hydrates or a test furnace. No high performance test data could be obtained.

[0005] The present invention has been made in view of the above-mentioned problems, and provides a furnace performance test method capable of obtaining reproducible and highly reliable performance test data in a furnace for incinerating wet combustibles. The purpose is to provide.

[0006]

SUMMARY OF THE INVENTION A furnace performance test method according to the present invention is a furnace performance test method for incinerating wet combustibles, including the step of incinerating wet pulp having a constant moisture content in the furnace. It is characterized by the following.

According to the furnace performance test method of the present invention,
Wet pulp is an alternative incineration material because its calorific value varies depending on the water content, and by preparing this wet pulp so as to have a constant water content, the moisture content can be adjusted as many times as desired regardless of time or place. It is possible to obtain alternative incineration materials with a corresponding constant calorific value.

Here, if the moisture content of the wet pulp is set so that the calorific value of the wet pulp substantially coincides with the calorific value of the water-containing combustible material, the incineration performance test of the furnace is performed as a simulation of the normal combustion state of the furnace. It is performed with higher accuracy.

When the wet pulp contains a coagulant, the affinity between water and pulp is improved, and a wet pulp containing water more uniformly can be obtained. In addition, the water retention of wet pulp is increased, the separation of water and pulp is suppressed, and the lubricity (sliminess) is improved, and the physical properties of wet pulp are made similar to those of wet combustibles.

[0010] The wet pulp preferably further contains yeast, so that the physical properties of the wet pulp are made more similar to those of humid combustibles.

[0011] Further, it is preferable that the hydrous combustible is sludge. The calorific value of the dried sludge is almost the same as the calorific value of the dry pulp, and it is easy to make the calorific value of the wet pulp coincide with the calorific value of the hydrous sludge. Therefore, the above-described performance test is more suitably performed.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
A preferred embodiment of the furnace performance test method according to the present invention will be described in detail.

FIG. 1 is a schematic diagram showing an apparatus used for a performance test of a furnace in the present embodiment. In the present embodiment, a wet pulp manufacturing apparatus 10 for preparing wet pulp,
A test furnace for obtaining data used for furnace design / improvement and the like, which includes a sludge incinerator 20 in which wet pulp prepared by the wet pulp manufacturing apparatus 10 is burned.

The wet pulp manufacturing apparatus 10 includes a hopper 8 for storing raw pulp, a crusher 2 for crushing the stored raw pulp, and a coagulant preparation tank 4 for dissolving the coagulant in water.
And a yeast storage tank 9 for storing yeast, a mixing and preparing machine 3 for mixing the aqueous solution of flocculant, yeast and crushed pulp to prepare wet pulp, and a storage tank 5 for storing the prepared wet pulp. ing.

As the crusher 2, a crusher such as a twin-screw type is used. The pulp supplied to the crusher 2 from the hopper 8 via the line L2 is finely crushed.
A line L3 for transferring the crushed pulp to the mixing and preparing machine 3 is connected to the crusher 2.

The raw pulp generally has a water content of about 50%, but if it is dried during crushing or the like, it becomes difficult to mix the pulp with the aqueous coagulant solution in the mixing and preparing machine 3. In the process of entering the mixing and preparing machine 3 from the hopper 8 via the crusher 2, it is preferable to cure the raw pulp and the crushed pulp so as not to dry.

The coagulant preparation tank 4 is a stirring tank provided with stirring blades. The coagulant preparation tank 4 has a line L1 for supplying a coagulant from a coagulant tank (not shown) and a line L0 for supplying water. And a line L4 for transferring the dissolved flocculant aqueous solution to the mixing and preparing machine 3 is connected.

The mixing / preparing machine 3 is a rotary cylinder-type mixing machine having stirring blades therein. The mixing / preparing machine 3 is connected to a line L10 for introducing yeast from a yeast storage tank 9 and is also provided with a mixing device. A line L5 for transferring the wet pulp prepared by stirring and mixing in the preparation machine 3 to the storage tank 5 is connected.

The storage tank 5 is a hopper for storing wet pulp. The storage tank 5 is provided with a discharge rotating blade inside for easily discharging wet pulp which is liable to be discharged due to a crosslinking phenomenon or the like. A wet pulp feeder 6 for transferring the wet pulp to the sludge incinerator 20 via the line L6 is provided at the lower part of the hopper. In addition, as the wet pulp feeder 6, it is preferable to use a pump for a high concentration solution such as a screw feeder or a pusher pump.

On the other hand, the sludge incinerator 20, which is a test furnace, is a bubble type fluidized bed furnace, and is installed on the furnace main body 1 and on the side of the furnace main body 1 and connected to the line L6 to be wet in the furnace main body 1. A feeder 7 for supplying pulp (sludge in actual operation); The lower part of the furnace body 1 is connected to a line L7 for introducing air or the like for fluidizing the internal fluid medium, the upper part is connected to a line L8 for discharging combustion exhaust gas, and the lower part is a non-combustible residue or the like. Line L9 for discharging oil
Is connected.

Next, a procedure of a performance test of the sludge incinerator 20 using such an apparatus will be described.

First, a wet pulp is prepared. First, the raw material pulp is supplied from the hopper 8 to the crusher 2,
Is driven to crush the raw pulp, and the crushed pulp is transferred to the mixing and preparing machine 3.

Here, as the raw pulp, bleached pulp having a small variation in the calorific value of the raw pulp itself in order to suppress the variation in the calorific value of the wet pulp and perform a performance test with higher accuracy and higher reproducibility. It is preferable to use unbleached pulp or the like. The crushed pulp is preferably 50 mm square or less in order to obtain uniform wet pulp.

On the other hand, in the coagulant preparation tank 4, after introducing a predetermined amount of water, a predetermined amount of the coagulant is introduced while driving the stirring blade, and the coagulant is dissolved to prepare an aqueous coagulant solution.

The type of the flocculant and the concentration of the flocculant aqueous solution are not particularly limited, but an anionic or nonionic flocculant is used in order to obtain wet pulp having good handleability and properties similar to sludge. Further, the concentration of the aqueous solution of these coagulants is preferably set to 0.01 to 0.3 wt%.

Next, the prepared aqueous coagulant solution is transferred to the mixing and preparing machine 3, and a predetermined amount of yeast is transferred from the yeast storage tank 9 to the mixing and preparing machine 3, and the stirring blades and the outer cylinder of the mixing and preparing machine 3 are removed. The crushed pulp, the flocculant aqueous solution and the yeast are mixed and stirred to prepare a wet pulp. At this time, the amount of the aqueous coagulant solution to be introduced is adjusted so that the moisture content of the wet pulp becomes a set value described later.
The amount of yeast added is 0 to the dry weight of the pulp.
It is preferably set to 50%.

At this time, since the wet pulp contains a flocculant, the affinity between water and the pulp is improved, and a more uniform wet pulp is obtained. Further, the water retention of the wet pulp is increased, the separation of the water and the pulp is suppressed, and at the same time, the pulp has lubricity (sliminess), so that a wet pulp having properties very similar to sludge can be obtained. Also, the addition of yeast makes the properties of wet pulp more similar to sludge.

Next, the set value of the moisture content of the wet pulp will be described in detail. In the performance test of the sludge incinerator 20, a more accurate performance test is required that the calorific value of the sludge to be incinerated in the sludge incinerator 20 and the calorific value of the wet pulp to be incinerated in the performance test are almost the same. It is preferable in performing. Here, FIG. 2 shows an example of the relationship between the moisture content of digested sewage sludge and undigested sludge and the calorific value, and FIG. 3 shows an example of the relationship between the moisture content of wet pulp and the calorific value. In FIG. 2, digested sewage sludge is indicated by a solid line, and undigested sewage sludge is indicated by a dashed line.

As is clear from FIGS. 2 and 3, the calorific value of sludge and wet pulp decreases with an increase in the water content and becomes zero at a water content of 100%. The maximum value of each calorific value, that is, the calorific value at the time of drying (water content 0%) is 4580, 3885 kc for undigested sewage sludge and digested sewage sludge, respectively.
al / kg, whereas pulp is 3900 kca
1 / kg, similar to each other. That is, the relationship between the moisture content of these sludges and the calorific value is very similar to the relationship between the moisture content of the wet pulp and the calorific value, and in particular, is substantially the same for digested sewage sludge. Therefore, by setting the moisture content of the wet pulp so that the heat value of the wet pulp is substantially the same as the heat value of the sludge to be burned in the sludge incinerator 20, the wet pulp having the same heat value as the sludge can be obtained. Pulp is easily obtained.

For example, in a general sewage treatment plant, sewage sludge is dewatered by a centrifugal dehydrator or a high-pressure dehydrator and then sent to a sludge incinerator, and the water content at this time is usually about 70 to 85%. . In this case, for example, the calorific value of the undigested sewage sludge having a water content of 70 to 85% is 1374 to 68 from FIG.
5kcal / kg (wet weight basis), 70-85%
The calorific value of digested sewage sludge having a moisture content of 1166 to 583k
cal / kg (based on wet weight), and to obtain a wet pulp having a calorific value in the same range (1374-583 kcal / kg), the moisture content of the wet pulp should be about 65-65.
What is necessary is just to set to any value between 85%.

Then, the wet pulp adjusted to the water content set as described above is transferred to the storage tank 5 and stored therein.

Subsequently, a combustion performance test of the sludge incinerator 20 is performed using the wet pulp having the water content adjusted as described above. First, a fluid medium in the furnace main body 1 is preheated by a preheating device (not shown), and a fluidizing gas is introduced from a line L7 so as to enable combustion in the furnace main body 1. Next, the wet pulp feeder 6 is driven while the discharge rotor of the storage tank 5 is rotated to prevent blockage due to bridging or the like, and the wet pulp is put into the furnace body 1. The input wet pulp burns while being stirred in the fluidized medium. At this time, it is investigated whether or not the wet pulp supplied at a predetermined supply amount is properly incinerated, and a furnace performance experiment is performed to obtain data such as a maximum load amount.

As described above, in the furnace performance test method of the present embodiment, the wet pulp having a constant water content is incinerated in the sludge incinerator 20. It becomes an alternative incineration substance by being close to the calorific value of the material, and by adjusting this wet pulp so as to have a constant moisture content, it can correspond to the predetermined moisture content any number of times without choosing any time or place. Since an alternative incineration substance having a constant calorific value can be obtained, reproducible performance test data can be obtained.

The constant moisture content is set so that the calorific value of the wet pulp substantially matches the calorific value of the sludge usually incinerated in the sludge incinerator 20. It is performed with even higher precision as a simulation of the normal combustion state of the furnace.

Further, the wet pulp exhibits the same properties as sludge, particularly sewage sludge, due to the viscousness (sliminess) generated in the wet pulp due to the improvement in water retention due to the addition of the coagulant.
Further, the performance test of the furnace is performed with high accuracy.

The furnace performance test method according to the present invention comprises:
The present invention is not limited to the above embodiment, and various modifications can be made.

For example, in the above embodiment, the moisture content of the wet pulp is set so that the calorific value of the sludge to be incinerated in the sludge incinerator 20 and the calorific value of the wet pulp are substantially the same. It is not limited to this. For example, when the calorific value of the sludge that is usually incinerated fluctuates greatly, the average value of the fluctuation may be used, or the maximum value or the minimum value may be used. Further, for example, a combustion test or the like under overload or underload may be performed by making the calorific value of wet pulp smaller or larger than the calorific value of sludge usually incinerated.

In the above embodiment, the wet pulp is prepared by mixing and stirring the crushed pulp, the aqueous solution of the flocculant and the yeast. However, the present invention is not limited to this, and any pulp mixed and prepared may be used. Absent.

In the above embodiment, a bubble type fluidized bed furnace is adopted as the sludge incinerator 20. However, the present invention is not limited to this, and is applicable to all types of incinerators such as a circulating type fluidized bed furnace and a stoker furnace. .

Further, in the above embodiment, the actual combustion target of the furnace is sludge. However, the present invention is not limited to this as long as it is a water-containing combustible material. For example, food waste may be used.

In the above embodiment, the wet pulp is burned in a test furnace. However, the present invention is not limited to this. For example, the test may be performed in an actual furnace, thereby confirming the capability of the furnace. And other furnaces.

[0042]

As described above, the furnace performance test method according to the present invention includes the step of incinerating a wet pulp having a constant moisture content in a furnace, and the wet pulp generates heat depending on the moisture content. Since the amount fluctuates, it becomes an alternative incineration substance, and by preparing this wet pulp so as to have a constant moisture content, a constant heat generation corresponding to the predetermined moisture content can be performed any number of times at any time, regardless of location, etc. Since it is possible to obtain a substitute incineration material having a sufficient amount, performance test data having high reproducibility and reliability can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an apparatus used for a performance test of a furnace in the present embodiment.

FIG. 2 is a diagram showing the relationship between the water content of digested sewage sludge and undigested sewage sludge and the calorific value.

FIG. 3 is a diagram showing a relationship between a moisture content of a wet pulp and a calorific value.

[Explanation of symbols]

 20 ... sludge incinerator (furnace).

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Otsuka 5-9-1-11 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sumitomo Heavy Industries, Ltd. (72) Takashi Nakagawa 5-9-1 Kita-Shinagawa, Shinagawa-ku, Tokyo No. 11 Sumitomo Heavy Industries, Ltd. (72) Inventor Isamu Inoue 1-15 Kuretsutsumi, Hiratsuka-shi, Kanagawa Prefecture F-term in the Environmental Technology Research Institute, Sumitomo Heavy Industries, Ltd. CB06 CB30 DB31 DB40

Claims (5)

[Claims] 1. A method for testing the performance of a furnace for incinerating a water-containing combustible, comprising the step of incinerating a wet pulp having a constant water content in the furnace. 2. The method according to claim 1, wherein the moisture content is set such that the heat value of the wet pulp substantially matches the heat value of the water-containing combustible. 3. The method according to claim 1, wherein the wet pulp contains a flocculant. 4. The method according to claim 3, wherein the wet pulp further contains yeast. 5. The method for testing the performance of a furnace according to claim 1, wherein the flammable material containing water is sludge.