JPS588A - Sludge incinerator furnace temperature control method - Google Patents

Abstract

PURPOSE:To prevent the fluctuations in furnace temperatures, in a sludge incinerator, through quick response temperature control without the need of auxiliary fuel being supplied by detecting furnace temperature in order to make feed quantity adjustable for the dried sludge cakes being supplied from their constant supplier. CONSTITUTION:The dehydrated cake 7 is fed into the indirect sludge drier 8 to be turned into the dried cake 1 in almost a powder form. When the furnace temperature shows fluctuations due to the dispersion in the properties of elements such as water content and calorific value of the dried cake 1 being fed into the furnace from the constant sludge cake supplier 17, the detector inserted in the fluidized bed furnace 2 outputs temperature signals to the temperature adjuster 3 which adjusts the number of revolutions of the variable-speed motor 22 of the sludge cake supplier 17. With this, the dried cake feeding quantity is adjusted to enable the furnace temperature to restore to its set level.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a furnace temperature control method for an incinerator that completely incinerates sludge generated from sewage treatment, urine collection, etc. The present invention relates to a management method for controlling the furnace temperature within the range of 700 to 950°C by adjusting the supply violet.

(1) Assisted combustion method The drying of the sludge cake is completed at a high rate of water that can be self-combusted, and the lack of heat violet required for self-combustion is made up for by supplying auxiliary fuel. cake 1'
The furnace temperature of the fluidized bed incinerator 2 to be incinerated is detected by the temperature controller 6, and the oil lid control valve 4 is adjusted according to the detected furnace temperature. Above incinerator 2
The temperature of the incinerator 2 is controlled by adjusting the electric oil (auxiliary fuel TP+) 6 (tJ supply prize).This method has the disadvantage of requiring auxiliary fuel, and also (2) Sludge dryer (indirect heating type) control force type As shown in Figure 2, the dehydrated cake 7 is dried and the dried cake 1 is dried. Then, the indirect heating type sludge drying machine 8 which supplies this dried cake 1 to the fluidized bed calcining furnace 2 is controlled according to the furnace temperature detected by the temperature regulator 3 K, and the dried cake 1 is By adjusting the water injection rate, the furnace of the P incinerator 2 is controlled. Or adjust the steam-saving valve 10 gold by the temperature controller 6, and dry the dryer 80.
The supply amount t of the drying steam 11 is full. In this method,
Detection of fluctuations in furnace temperature and control of the motor 9 or the control tube τ of the node 110 are carried out instantaneously, but the control cost takes a few seconds until the water injection rate of the dried cake 1 reaches the target value GC7C.
There was a time delay of about 0 minutes, and there was a drawback that it was difficult to actually control the furnace temperature. In addition, in Fig. 2, the reference numeral 1
This indicates 2Fi drain @ (3) Water injection method Dry the dehydrated cake to a value lower than the amount of water injection that can self-combust,
The heat input τ to the furnace is always supplied in excess, and this excess gsj minute t@3
! 4, in order to remove water by injecting water into the incinerator 2, the cooling water 13 is adjusted according to the furnace temperature by the control valve 14t and the above-mentioned temperature controller 3 that detects the furnace temperature sound of the incinerator 2. This adjustment is fully controlled by the milling furnace. This method has the following drawbacks (,) to (d): (a) Water injection causes damage to the refractories in the furnace.

(b) Unevaporated mist mixes with the exhaust gas and causes corrosion of gas processing equipment such as the furnace.

(c) The amount of gas 1 increases due to water injection, and the gas treatment equipment becomes thicker. (d) The required drying heat medium (steam, etc.) increases in amount.

(4) Cake supply lid control method to sludge dryer As shown in FIG. i
1! 't-fIIIm, and the controller 3 controls the motor 9 or 15 to feed the cake.
t-control. The motor 9 is for feeding the cake in the sludge dryer 8, and by controlling this motor 9, the residence time of the cake in the dryer 8 is controlled. The motor 15 drives the conveyor 16 that conveys the dehydrated cake 7 to the dryer 8. By controlling this motor 15, the amount of fresh water cake 70 supplied to the dryer Mk 8 per unit time is controlled.

In this method, the dehydrated cake 7 is supplied to the drying machine 8.
&) Due to the change, the amount of heat received by the dryer 8 also changes, and therefore the amount of water injected into the cake at the outlet of the dryer 80 also changes at the same time. The present invention aims to eliminate the above-mentioned drawbacks of the conventional method, and is to deal with fluctuations in furnace temperature caused by variations in the amount of heat brought in by the dried cake. Supply of dry cake tt--
It is intended to stably maintain the furnace rML within an appropriate range, and the dehydrated cake obtained by dehydrating sludge generated from sewage treatment and urine treatment is heated with steam, hot water, and heat medium. It is heated in an indirect sludge dryer using oil, etc., and is self-combustible, similar to powder.In the process of self-combustion in a fluidized bed incinerator, the temperature inside the furnace is detected and the sludge is supplied to the furnace from fixed quantity supply a. Dry cake neck - Adjust oven temperature to 700-950.
Furnace of fluidized bed incinerator for self-combustible sludge controlled within the range of °C
It is related to the process.

The above is a description of the embodiment drawings of the present invention.
In the figure, a dehydrated cake 7 discharged from a dehydrator (not shown) is first fed into an indirect sludge dryer 8.
It is dried with violet to a certain degree to form a dry cake 1 that is close to powder. 9 is a motor for feeding cake 9 in the sludge dryer 8, and 12 is a drain. The dried cake 1 is temporarily stored in a sludge feeder 17 with a hopper. The dried cake 1 needs to be dried to a powder-like state as described above in order to prevent crosslinking when stored in the sludge feeder 17 with a hopper. Next, the dried cake 1# is quantitatively cut out from the sludge feeder 17 and fed into the fluidized bed incinerator 2 via the sludge feeder 18 which uniformly feeds the cake.

Ordinary sewage, edge sludge cake Since the highest temperature occurs in the sand layer, a water resistant 21c nozzle to #i waste heat boiler 20 is branched and supplied to the cooling pipe 19 installed in the sand layer. , the steam generated in the fJJ pipe 19 is removed by a waste heat boiler 20 and introduced into the sludge dryer 8. Due to the fluctuation in the properties of the dry cake 1 fed into the furnace from the sludge fixed lid supply tank 177J,
When the furnace temperature change IA occurs, #iL is inserted into the moving bed incinerator 2, and the temperature is changed to the temperature of the sludge feeder 17 via the regulator 3 by the temperature signal from one or more detection terminals (not shown). 01 f Adjust the rotation speed of the motor 21 and serve the dry cake.
ix to return the furnace temperature to the set value.

That is, when the furnace m exceeds the set value, the output shaft rotation speed of the electric motor 22 causes the dry cake 1 to be fed into the incinerator 2.
0'jkt - decrease the furnace width to the set value tr, conversely, if the furnace temperature is below the set value, the electric motor 22cD output 4
11 (b) Increase the number of rotations and increase the supply lid for dry cake 1.
lJ and raise the furnace temperature to the set value.

(23) indicates combustion air at room temperature.

Next, examples of trial calculations related to the present invention are shown in Tables 1 to 3.

m1 batter Trial calculation conditions Table 2 Changes in furnace melting due to changes in dry cake properties However, 1
．． It is assumed that the treatment jt is constant (896 KV'H).

2. The combustion air cover is constant.

Table 3 Dry Recording - Ayu TII4 Bungo Furnace As shown in Table 2, when both the moisture content of the rC5 dry cake and the ignition loss change, the temperature inside the furnace will be 850 CM4 U61, which is the set value.
0 to 10801C Het iJmt4° However, in a fluidized bed incinerator, the temperature inside the furnace is υ, where the combustion power is indeterminate at 700°C or less as a result of a trial using a test ground, and the temperature inside the furnace (sand layer) is below m degrees @ is 700°C, and since the sludge turns into an ink at 950°C or higher, it is assumed that the upper limit of the temperature in the furnace (sand layer) is 950°C. Therefore, as a result of the fluctuations in the properties of the dried cake shown in Table 2, it is clear that continuous operation of the incinerator will cause problems.

Therefore, in response to changes in the properties of the dried cake, kIJ
The third step is to adjust the line cake feeder to the general value of 85 to 125 degrees. As shown in the table.

As mentioned above, the present invention first converts a dehydrated cake into a dry cake that is close to powder. ! It is an energy-saving type that does not require supplementary sa'i because it dries more quickly than sweat and water. In addition, the dried cake is temporarily stored in a hotsuber, and
It detects temperature fluctuations and uses the temperature signal to control the sludge feeder with hopper (23)' to directly adjust the amount of dried cake to be fed to the furnace.
Rare. Also, the dried cake is close to powder (because it is dried, it does not produce crosslinking noise when stored in the hopper).
# Nida violet is fed into the furnace through sludge input & from sludge supply f @ Iso 17 (/i can prevent fluctuations in the furnace hood FM due to variations in dry cake feeding carp supply, The furnace temperature can be easily maintained within a stable range of 700 to 950°C.

In addition, if the rolled cake is dried to a state close to powder,
As mentioned above, the dried cake generates more heat i1 than is required for self-combustion (moon-fΦ), so the excess heat tt can be recovered by cooling 119 inserted into the sand layer and reused, contributing to energy conservation. If the ignition loss in the dehydrated cake 7 is low, such as a cake or a dehydrated cake using lime as a coagulant, cooling 1 #19 may not be provided, and in this case as well,
It goes without saying that the yJ method of the present invention allows for proper control of the furnace temperature (c).

[Brief explanation of the drawing]

1st, 2nd, 3rd and 4th diagrams show the conventional method of managing the incinerators of the incinerator f:, and Figure 5 shows the system of one example of the present invention. It is a diagram. 1...Dried cake, 2...Flow 1kt 1 layer incinerator, 7
...Dehydrated cake, 8...Sludge dryer, 17...Sludge machine with hopper, #iso, 18...Sludge removal machine.

Claims (1)

[Claims] The dehydrated cake obtained by dehydrating sludge that is often generated during sewage treatment, urine collection treatment, etc. is made into a dry cake that is similar to powder using a sludge dryer. In the process of first storing the sludge, then supplying it to the fluidized bed incinerator via the sludge supply ridge and sludge injector for self-combustion.
Inside the furnace! ft-Detected sludge supply #aeρ) and dry recycle cake jltf: y4 adjusted, furnace temperature 700
A method for controlling the furnace temperature of a sludge incinerator, which specifically controls the temperature within the range of ~950°C.