JPH03239793A - Control of combustion of gas generated from dry distillation kiln - Google Patents

Abstract

PURPOSE:To effectively utilize a gas and excess oil generated during dry distillation by separating a burner for heating a dry distillation kiln into an oil burner and a gas burner which makes use of the gas generated from the dry distillation kiln as fuel. CONSTITUTION:A block of, e.g. stainless steel grinding dust is placed in a dry distilla tion object container 28. After placing the container 28 in a dry distillation kiln 10, an electric motor 40 is started to rotate a fan 26 in the kiln 10. An oil burner 18 which makes use of oil recovered from prior dry distillation as fuel is ignited to heat the object inside the dry distillation kiln 10. If the temp. of the block increases, cutting oil contained inside the block evaporates. Oil liquefied by condensation in a gas pipe 11 is sent into an oil recovery tank 15 through an oil cooling unit 12. Also, oil which has not been condensed in the gas pipe 11 is condensed by means of a con denser 13 and is sent into a recovered oil tank 16. Since the gas passed through the condenser 13 contains a low-molecular inflammable gas which is not liquefied, it is fed into a gas burner 19 through a water seal tank 14 for eliminating back fire. In generating the gas, the dry distillation kiln is heated by means of the gas burner 19 and the heat shortage is supplied by heating by means of the oil burner 18.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a combustion control method for effectively utilizing gas generated by carbonization as fuel for a carbonization tank.

[Conventional technology]

In a conventional carbonization apparatus, for example, an organic waste carbonization gas generation apparatus described in JP-A-57-128785,
A large number of heat transfer particles are placed in a carbonization furnace, organic waste such as rice husks is placed inside, and the organic waste is combusted in advance.
BACKGROUND ART A carbonization gas generation device for organic waste has been proposed, which carbonizes organic waste in a semi-combusted state and a carbonized state and recovers the generated gas.

[Problem to be solved by the invention]

However, in the apparatus for generating carbonized gas from organic waste described in JP-A-57-128785, since the material to be carbonized is directly burned, there is a risk that the material to be carbonized may be oxidized. It is not suitable for carbonizing stainless steel grinding waste containing grinding oil generated during grinding and polishing processes in manufacturing plants.

Therefore, we experimented with the idea that by putting materials to be carbonized, such as stainless steel grinding waste, into a carbonization pot and carbonizing them in a non-oxidizing atmosphere, the carbonized stainless steel grinding waste could be effectively used as a raw material for steelmaking. It has been found that if the gas and oil used in the process are used efficiently, the entire process can be done without using any external fuel.

The present invention has been made in view of the above circumstances, and aims to provide a method for controlling the combustion of gas generated from a carbonization tank, which can effectively utilize the gas generated during carbonization and can also recover excess oil. purpose.

(Means for Solving the Problems) A method for controlling the combustion of gas generated from a carbonization boiler according to claim (1) that meets the above object is a method for controlling the combustion of gas generated from a carbonization boiler, which uses gas generated by carbonization as fuel for heating the carbonization boiler. A gas combustion control method, in which the burner for heating the carbonization tank is divided into an oil burner and a gas burner that uses gas generated from the carbonization tank as fuel, and the carbonization tank is heated in advance with the oil burner to generate gas. Sometimes, the lack of heat from the gas burner is supplemented by the oil burner.

Further, the method for controlling the combustion of gas generated from the carbonization vessel according to claim (2) is the method according to claim (1), in which a constant combustion burner is provided outside the carbonization vessel, and the surplus gas generated from the carbonization vessel is It is designed to burn.

The method for controlling combustion of gas generated from the carbonization vessel according to claim (3) is the method according to claim (1), wherein the fuel for the oil burner is constituted by oil generated from the carbonization vessel.

[Effect]

In the method for controlling the combustion of gas generated from a carbonization tank according to claims (1) to (3), the burner for heating the carbonization tank is divided into an oil burner and a gas burner, the oil burner is used for heating in advance, and when gas is generated, The gas is burned in the gas burner, and the insufficient amount of heat is burned in the oil burner, so oil can be saved, and the saved oil can be discharged into a container such as a drum and used for other fuels. be able to.

In particular, in the method for controlling the combustion of gas generated from a carbonization vessel according to claim (2), a constant combustion burner is provided outside the carbonization vessel to burn excess gas generated from the carbonization vessel. Even if excess gas is generated,
There is no need for a storage tank or the like for the generated gas, and furthermore, the excess gas is burned and released into the atmosphere, so it is safe.

〔Example〕

Next, embodiments embodying the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention.

Here, FIG. 1 is a schematic flow diagram of a carbonization equipment to which the method for controlling combustion of gas generated from a carbonization reactor according to the present invention is applied, and FIG. 2 is a flow diagram showing a part of the method for controlling combustion gas in the carbonization equipment. It is a diagram.

As shown in the figure, the carbonization equipment includes a carbonization tank 10 having a lid that can be opened and closed, and an oil cooling device 1 disposed in the carbonization gas passage of the carbonization tank 10 to cool the oil condensed and liquefied in the gas pipe 11.
2, a condenser 13 that cools carbonized gas and liquefies it into oil and water, a water seal tank 14 connected to the outlet side of the condenser 13, and a condenser 13 that cools the carbonized gas and liquefies it into oil and water; Recovered oil tank 15
．． 16, a storage tank 17, and an oil burner 18 that heats the carbonization vessel 10 using carbonized gas and oil as fuel.
, a gas burner 19, a combustion burner 20, a combustion fan 21 that supplies primary air to each of the burners, a cooling tower 22 that cools circulating cooling water, and a control device 23 for these. has been done. These will be explained in more detail.

The carbonization pot 10 is made entirely of a container made of stainless steel or heat-resistant steel, and has a mounting table 24 made of supporting members arranged at appropriate intervals inside, and a lid 25 with an opening/closing device provided on the top. , Inside the M25, a stirring fan 26 and a baffle plate 27 for guiding gas from the lower part of the fan 26 and discharging it to the side are provided.

Above S! On the placing stand 24, there is a cylindrical body having an outer diameter sufficiently smaller than the inner diameter of the carbonization vessel 10, which is divided into four equal parts in the vertical direction.
Carbonized distillate storage containers 28 are arranged. This carbonized distillate storage container 28 has an open top and a net-like bottom, so that the gas sent by the fan 26 is transferred to the carbonized distillate storage container 28.
The air passes through the outside of the dry distillate container 28, enters the inside from the bottom of the container 28, and is circulated again by the air baffle plate toward the fan 26 at the top.

A gas pipe 11 is attached to the carbonization pot IO as an exhaust gas passage for sending the generated gas to the outside.
1 (preferably installed at the lowest position), an oil cooling device 12 is installed via a branch pipe. This oil cooling device 12 is for cooling high flash point oil (that is, high boiling point oil) condensed in the gas pipe 11, and after cooling, the oil is stored in a recovery oil tank 15 having a partition plate inside. The oil floating on the surface is allowed to overflow to the adjacent area and collected.

A condenser 13 whose interior is forcibly cooled by cooling water is connected to the end of the gas pipe 11 to condense and liquefy the oil and water contained in the carbonized gas, and guide it to the recovered oil tank 16. ing.

This recovered oil tank 16 also has a partition plate inside, and only the oil floating on the surface overflows from the partition plate and is guided to the adjacent area.

The oil collected in the collected oil tank 15.16 is pumped to the pump 29.
30 to the storage tank 17 and used as fuel oil. In this case, the recovered oil with a low flash point collected in the recovered oil tank 16 is sent to the storage tank 17 with priority, and if there is insufficient fuel oil, the high flash point oil in the recovered oil tank 15 is also sent to the storage tank 17. use. In addition, if there is surplus fuel oil, it can be dispensed into drums, etc., and used effectively for fueling other equipment.

A water seal tank 14 is attached to the outlet side of the condenser 13 via a valve 31, and the gas generated through the water seal tank 14 is supplied to a gas burner 19 and a constant combustion burner 20, which is an example of a gas burner. This prevents it from backfiring.

The water separated in the oil recovery tanks 15 and 16 and the water overflowing from the water seal tank 14 are discharged to the outside of the system without containing any oil through an oil-water separator (not shown).

An oil burner 18 and a gas burner 19 are provided at the lower part of the carbonization tank 10, oil is supplied to the oil burner 18 from the storage tank 17 via a pump 32, and the gas burner 19 is connected to a water seal tank. 14, three-way control valve 3
Gas generated by carbonization is supplied through 3, so that the carbonization tank IO can be heated from the bottom.

The gas generated in excess by carbonization is burned in the constantly burning burner 20 and released into the atmosphere from the chimney 34, and each burner 1B, 20 has LPGa5
It is equipped with a pilot burner that uses fuel as fuel.

On the other hand, n is connected to the condenser 13 via a valve 36.
A ring fan 37 is attached so that the gas cooled by the condenser 13 can be sent again to the carbonization tank 1O, and a nitrogen gas tank 39 is connected to the carbonization tank 1O via a valve 38. Nitrogen gas can be filled inside the carbonization vessel 10 if necessary.

Next, the operation of the carbonization equipment will be briefly explained.

Stainless steel grinding waste generated during the process of polishing stainless steel plates with a polishing belt is collected, transported to a press factory, placed in a cylinder, and squeezed from the top with a piston to extrude cutting oil into a cake-like lump (180 mm in diameter).
, height 60-100mm). As a result, the oil content of the lumps becomes approximately 15%.

Next, this lump is placed in the four carbonized distillate storage containers 28 described above.
and put it in the carbonization vessel 10, sealing the whole with 125, opening the valve 38 to introduce nitrogen gas from the nitrogen gas tank 39, expelling the air inside to create a non-oxidizing atmosphere, and closing the valve 38. close.

First, the electric motor 40 is driven to rotate the fan 26 in the carbonization vessel 10, igniting the viroft burner that uses LPG as fuel, and burning the oil burner 18 that uses oil recovered from the previous carbonization as fuel. let At this time, it is assumed that the pulp 31 connected to the condenser 13 is opened and the valve 36 is closed.

As a result, the inside of the carbonization tank 10 is heated, and the airflow released from the internal fan 26 to the surroundings passes between the outside of the four carbonization storage containers 28 and the inside of the carbonization tank 10, and the airflow flows into the carbonization tank 10. It moves toward the bottom of the IO, is heated, rises from the bottom of the carbonized distillate storage container 28 through the gap between the lumps, and is collected directly under the fan 26 by the air baffle plate 27 to form a va-ring.

When the temperature of the lump increases, the cutting oil contained inside evaporates and is discharged from the carbonization tank lO, and the oil with a high flash point that has passed through the gas pipe 11 is condensed and liquefied in the gas pipe lO, and the oil cooling device 12 , cooled and sent to a part of the recovery oil tank 15 .

The oil that overflows from a part of the recovered oil tank 15 flows into the adjacent tank and is pumped into the storage tank 17 by the pump 29.
sent to.

The oil that did not condense in the above gas pipe 1 is transferred to condenser 1.
3, the oil containing low flash point oil (that is, oil containing low flash point oil) is collected and sent to the recovery oil tank 16, and only the overflowed oil is transferred to the storage tank 17. It is transported by a pump 30.

Since the gas that has passed through the condenser 13 contains low-molecular flammable gas that does not liquefy, it is supplied to the gas burner 19 through the water seal tank 14 for preventing backfire, and then
used as a heat source for heating.

Here, the three-way control valve 33 is controlled by a deceleration motor (not shown), and a part of the gas sent to the combustion burner 20 is controlled by a deceleration motor (not shown).
In addition, the oil burner 18 is provided with a fuel control section driven by a deceleration motor (not shown), and the amount of oil to be supplied can be reduced to 30% of the maximum supply amount. The entire system is controlled by a computer located within the control device 23. The operation will be explained with reference to FIG.

First, in the first period of carbonization, since no gas is generated from the carbonization tank 10, the oil burner 18 is ignited using the oil stored in the storage tank 17 as fuel. Assuming that the set temperature in the furnace is To and the temperature measured by the thermometer 41 is T, first in step A, read the furnace temperature T1,
Set temperature T6 (e.g. 800°C) in step B
Read.

Next, in step C, it is determined whether ('re -T, ) is positive or negative, and if it is positive, it means that the temperature inside the furnace is low, so in step D, the three-way control valve 33 is fully opened (limited) to the gas burner side. If it is fully open, the deceleration motor of the oil burner 18 is driven to allow a large amount of oil to flow through the fuel control section (step E).

Thereafter, in step F, a small timer (approximately 2 seconds) is counted, and steps A to E are repeated to set the oil burner 18 to the maximum and raise the furnace temperature.

As a result, gas is generated from the carbonization tank 10, is supplied to the gas burner 19 through the condenser 13 and the water ring tank 14, and is used as fuel to heat the carbonization tank 10, and the furnace temperature further increases. When T, -T, ) becomes negative, it is confirmed in step G that the oil burner 18 is not at the minimum (detected by the limit switch), and the reduction motor is driven to adjust the oil supply amount of the fuel control section. It is controlled to decrease (Step H). After this, count the car timer (step F) and repeat steps A-C above.
G and H are obtained, and the oil burner 18 is throttled in accordance with the increased amount of gas.

Gas generation increased from carbonization pot lO, and oil burner 1
8 is at the minimum position, confirm in step G that the oil burner 18 is at the minimum position, and open the three-way control valve 33 to allow gas to flow to the regular combustion burner 20 side ( Step I).

As a result, excess gas is combusted by the constant combustion burner 20 and discharged from the chimney 34.

Here, if the three-way control valve 33 is opened too much, the temperature inside the furnace will drop below the reference temperature, so this is determined in step C, and in step D it is determined whether or not the three-way control valve is fully open to the gas burner 19 side. The three-way control valve is activated (step J), the flow rate of the gas burner 19 is increased, the oil burner 18 is always kept at the lowest level, and the combustion temperature is kept constant by controlling the three-way control valve 33. .

Note that the temperature of the carbonization pot 10 is about 500°C on average,
The maximum temperature shall not exceed 800°C.

As a result, the lumps are exposed to high temperatures and the cutting oil contained inside them almost completely evaporates, and when carbonization is performed in a non-oxidizing atmosphere, the nickel, chromium, etc. contained in the lumps remain in a state where they are not oxidized. When the carbonization that can be retained is almost completely completed, no polymer gas, which is a component of the cutting oil, is generated inside the fan 26, so the load on the fan 26 becomes smaller, and furthermore, no carbonization gas is generated, so the temperature inside the gas pipe 11 decreases. Also, since the temperature of the water that cools the flange of the lid 25 also decreases, one or more of these phenomena is detected and the gas burner 1 is
9. Turn off the oil burner 18.

After the carbonization is completed, the valve 38 is opened to introduce nitrogen from the nitrogen gas tank 39, and the gas remaining in the carbonization tank 10 and gas pipe 11 is expelled, thereby preventing the condensation and accumulation of oil in the carbonization tank 10 and gas pipe 11. To prevent.

After this, the valve 31 is stopped, the valve 36 is opened, and the fan 37 is driven to flow the gas in the carbonization reactor 10 through the condenser 13 II! let In this case, in order to prevent the temperature from falling and the pressure from becoming negative, the valve 38 is opened at any time to fill the inside with nitrogen in response to the pressure drop in the carbonization vessel. Since cooling water cooled by the cooling tower 22 is circulated through the condenser 13, the temperature of the non-oxidizing gas inside the condenser 13 is rapidly lowered, and thereby the temperature of the carbonized lumps is also lowered to near room temperature.

When the temperature of the lump has fallen (to the extent that the lump does not oxidize due to its own heat), the fan 26 is stopped, the lid 25 is opened, and the lump inside is taken out. This completes the recycling of the stainless steel grinding waste into steelmaking raw materials, but the oil content of the lumps taken out from the carbonization pot 10 was actually measured to be less than 0.1%, and no progress of oxidation was observed.

In the above embodiment, the lower limit of the control range of the oil burner 18 was set to 30%, but if necessary, it is also possible to use a special burner or multiple burners and turn it off completely, leaving only the pilot burner. It is.

Further, in the above embodiments, stainless steel grinding waste was used as the material to be carbonized, but other waste materials can be treated in the same manner.

〔Effect of the invention〕

As is clear from the above description, the method for controlling the combustion of gas generated from a carbonization boiler according to claims (1) to (3) divides the burner that heats the carbonization boiler into a gas burner and an oil burner, and The carbonization tank is heated by an oil burner, and when gas is generated, the oil burner supplies the amount of heat that the gas burner lacks, so excess oil can be recovered and used for other equipment, saving oil. can.

In particular, in the method for controlling the combustion of gas generated from the carbonization vessel as set forth in claim (2), a constant combustion burner is provided outside the carbonization vessel to burn excess gas generated from the carbonization vessel. Even if the material to be carbonized generates gas, by carbonizing it at an appropriate temperature without raising the temperature of the carbonization tank too much, damage to the carbonization tank due to heating can be prevented, and the gas generated can be treated. .

[Brief explanation of drawings]

FIG. 1 is a schematic flow diagram of carbonization equipment to which the method of controlling combustion of gas generated from a carbonization reactor according to the present invention is applied, and FIG. 2 is a flow diagram showing a part of the method of controlling combustion gas of the carbonization equipment. . [Explanation of symbols] 1O...--carbonization tank, IL---gas pipe,
12 Oil cooling device, l 3---Condenser, 14
Water sealing tank, 15.16-------Recovered oil tank, 1
7--------Storage tank, 18-- Oil burner, 19-- Gas burner, 20-- Permanent burner, 21-- Combustion fan, 22- ---
・-Cooling tower, 23---1--control device, 24-mounting table, 25--lid, 26-------fan, 27------1 air regulating plate, 2 B-- ----1 Carbonic distillate storage container, 29.30,---1---Pump, 31-1...Valve, 32---Pump, 33
-1---Two-way control valve, 34 chimney, 35---L
PG, 36---- Valve, 37------
・ , Fan, 3 B------Valve, 39 Nitrogen gas tank, 40----1 Electric motor 41----1
thermometer

Claims (3)

[Claims] (1) A method for controlling the combustion of gas generated from a carbonization vessel, in which the gas generated by carbonization is used as fuel for heating the carbonization vessel, the method comprising:
The burner that heats the carbonization tank is divided into an oil burner and a gas burner that uses the gas generated from the carbonization tank as fuel, and the carbonization tank is heated in advance with the oil burner, and when gas is generated, the insufficient amount of heat of the gas burner is absorbed. A method for controlling combustion of gas generated from a carbonization boiler, characterized in that the oil burner is used to supplement the combustion of gas. (2) Claim (1) in which a constant combustion burner is provided outside the carbonization vessel to burn excess gas generated from the carbonization vessel.
A method for controlling the combustion of gas generated from the described carbonization kettle. (3) The method for controlling combustion of gas generated from a carbonization vessel according to claim (1), wherein the fuel of the oil burner is oil generated from the carbonization vessel.