HK1234766A - Carbon black reactor - Google Patents

Description

Carbon black reaction furnace

The application is a divisional application of a Chinese patent application named as a carbon black reaction furnace with application number 201180021230.0, and the patent application 201180021230.0 is a national application entering the Chinese national stage according to the patent cooperation treaty about International application (PCT/IN2011/000262) filed on 19/4/2011.

Technical Field

The present invention relates to a reaction furnace for producing carbon black. In particular, the present invention relates to a reactor that can better mix carbon-based feedstock and combustion air when making carbon black.

Background

Processes for making carbon black typically include partially pyrolyzing a carbon-based feedstock, where the feedstock may be in gaseous or liquid form. While there are a variety of processes for obtaining carbon black, the most common is the furnace black process, which utilizes a liquid feedstock composed of heavy petroleum products such as incompletely combusted FCC tar, coal tar, and ethylene pyrolysis tar to produce carbon black.

In the furnace black process, a hydrocarbon fuel (such as natural gas or fuel oil) is typically combusted with excess oxygen supplied in the form of an air stream or oxygen-containing gas in a refractory lined space to produce a high temperature combustion gas. The liquid feedstock to be pyrolyzed and dehydrogenated is sprayed into a high temperature combustion gas to obtain carbon black particles suspended in the gas. The carbon black particles in the form of fluffy powder are separated and collected from the gas. The collected granules were then granulated by conventional granulation methods. Carbon black is used in the manufacture of pneumatic tyres for cars and airplanes, as reinforcing filler for elastomers, as pigment or colorant for plastics, paints and printing inks.

A reaction furnace for the furnace black process generally comprises a combustion chamber, a mixing chamber and a reaction chamber, which are arranged along the axis of the reaction furnace to form a reaction medium flow path from the combustion chamber to the reaction chamber via the mixing chamber. The liquid feedstock is typically sprayed in a mixing chamber to achieve high density mixing of the liquid feedstock with the high temperature combustion gases. The mixture then enters the reaction chamber where the actual soot formation process takes place. Finally, the downstream water spray stops the reaction.

Factors that affect carbon black formation include: excess air/oxygen in the high temperature combustion gases, the combustion efficiency of the fuel, and the reaction or residence time from mixing of the feedstock in the high temperature combustion gases to completion of the reaction. The combustion efficiency of a fuel depends to a large extent on the degree of mixing of the fuel with the combustion air/oxygen. Typically, the combustion air is preheated in the combustion chamber to a temperature of around 800 ℃ and then mixed with fuel to obtain high temperature combustion gases. Improving the mixing between the combustion air and the fuel may increase the combustion efficiency, thereby increasing the temperature of the high temperature combustion gases. Generally, the higher the temperature of the high temperature combustion gas, the smaller the carbon black particles formed.

Carbon black reactors have been provided in the past with improved furnace black technology to increase efficiency, improve process control, and produce carbon black grades of varying accuracy. Some of the prior art disclosures are as follows:

U.S. patent No. 7625527 discloses a carbon black reaction furnace that increases the conversion of feedstock to carbon black by increasing the contact efficiency between high temperature combustion gases and the feedstock. The composition of the carbon black reaction furnace comprises: a combustion zone for producing high temperature combustion gases; a reaction zone having two or more points of introduction of feedstock for producing carbon black by contacting combustion gases with a plurality of feedstock introduced using a split flow; the three zones are arranged laterally in sequence by a quench zone into which a coolant is injected to stop the reaction. The carbon black obtained from the carbon black reactor has uniform characteristics, especially with respect to the polymer size distribution.

Chinese patent No. 2341708 discloses a carbon black reactor-surface oxidation and fluidized bed. The reaction furnace comprises the following components: the reactor comprises a reactor main body, a furnace black inlet, a furnace black outlet, a compound distribution plate, an air chamber, an air inlet and an air outlet, wherein 3 to 7 partition plates are arranged in the reactor to form 4 to 8 fluidization chambers so as to obtain multi-stage mixed flow. The reaction furnace is simple to manufacture and low in cost, and can be used for producing carbon black for coloring in various industries.

U.S. patent No. 4590040 discloses a carbon black reactor furnace modified to reduce the pressure drop caused by excessive turbulence in the pre-combustion zone. The composition of the carbon black reaction furnace comprises: a pre-combustion zone having a cylindrical sidewall, an upstream end, and a downstream end; a plurality of passages for conveying combustion gases, the passages opening through the side wall in a tangential direction to the pre-combustion zone; a plurality of semi-circular ramps within the pre-combustion zone defining an upstream end for directing the flow of combustion gas vapors introduced tangentially. The device avoids the turbulent influence between other tangentially introduced gas vapours to reduce the resulting pressure drop.

One device disclosed in us patent No. 4347218 can be used to produce carbon black grades of varying accuracy while, inter alia, avoiding thermal overloading of the reactor in the hydrocarbon and air entry zones. The device comprises the following components: a reaction furnace comprising a reaction chamber for forming carbon black; a plurality of maskless feeders for supplying air to the reaction chamber and spraying hydrocarbon to the air near the discharge end; and the heat exchanger is used for controlling the temperature of the output air of the reaction furnace and the generated carbon black.

U.S. patent No. 2004213728 discloses a process for producing furnace black in a furnace black reactor having a flow shaft. The process comprises the following steps: introducing fuel and combustion air into the gas burner and injecting steam axially through the gas burner to produce a high temperature combustion gas stream within the combustion chamber; feeding high temperature combustion gas from the combustion chamber through a narrow point along the flow axis into the reaction zone, mixing the carbon black raw material into the high temperature combustion gas upstream, midstream or downstream of the narrow point; water is sprayed to stop the reaction downstream of the reaction zone. The process produces dark furnace black in the reaction furnace.

The above listed prior art disclosed carbon black reactors are modified to improve process efficiency, enhance process control or provide different precision carbon black grades. The present invention is directed to such carbon black reactors, and is primarily modified to enhance the mixing of combustion air/oxygen and fuel, to increase combustion efficiency and to provide higher temperature combustion gases. In addition, the invention also provides a carbon black reaction furnace composition device, which can improve the flow rate of raw materials passing through the reaction furnace and simultaneously maintain the quality parameters of the carbon black.

Disclosure of Invention

It is an object of the present invention to provide a reaction furnace for producing carbon black.

It is another object of the present invention to provide a reactor furnace that improves the mixing of combustion air and fuel in a combustion chamber during the carbon black manufacturing process.

It is still another object of the present invention to provide a reactor furnace assembly that can increase the flow rate of feedstock through the reactor furnace without any loss of quality.

It is a final object of the present invention to provide a reactor for manufacturing carbon black that improves process efficiency and product quality.

The invention discloses a reaction furnace for manufacturing carbon black by using a furnace black process, which comprises the following components:

■, for generating hot combustion gases, said combustion chamber consisting of:

● a fuel burner located on the operative longitudinal axis of the reactor;

● an air inlet perpendicular to the fuel burner for receiving combustion air;

● located on the operative longitudinal axis of the reactor, adjacent the fuel burner and intermediate the fuel burner and the air inlet, and thus in the path of the combustion air flow to change the flow path;

■ is located in the reaction chamber after the combustion chamber on the operative longitudinal axis of the furnace, the reaction chamber being adapted to receive high temperature combustion gases from the combustion chamber and a carbon-based feedstock to form carbon black.

According to the invention, the flow guiding means is typically a set of annular cylinders.

According to the invention, the flow guiding means may also be a set of tapered annular cylinders.

According to the invention, the flow guiding means is preferably selected from at least one of a uniform annular cylinder, a tapered annular cylinder, a baffle, a vane and a combination of similar means.

Alternatively, the flow directing means may be a set of annular cylinders and at least one means selected from baffles, vanes and vanes arranged along the effective operating length of the cylinders in accordance with the present invention.

The invention discloses a process for manufacturing carbon black, which comprises the following steps:

■ burning the fuel in a fuel burner located on the longitudinal axis of the effective operation of the reactor to produce carbon black;

■ receive combustion air through air inlets perpendicular to the fuel burner;

■ changing the flow path of the combustion air by means of flow guides on the operative longitudinal axis of the reactor, between the fuel burner and the air inlet, near the fuel burner;

■ to create efficient mixing between combustion air and fuel within the combustion chamber to produce high temperature combustion gases at temperatures between 1000 ℃ and 2200 ℃;

■ receive high temperature combustion gases in the reaction chamber after the combustion chamber on the operative longitudinal axis of the furnace and feed carbon-based feedstock to produce carbon black.

In accordance with the present invention, the process generally includes producing a carbon black grade selected from the group of hard black to soft black grades.

Drawings

The invention will now be described with the aid of the accompanying drawings, in which:

FIG. 1 is a schematic illustration of a carbon black reactor showing the flow directing device of the present invention;

FIG. 2 is a schematic view of an alternative flow directing device for a carbon black reactor of the present invention.

Detailed Description

The invention will now be described with the aid of the accompanying drawings, which do not limit the scope of the invention. The description provided is purely by way of example and schematic.

The invention designs a reaction furnace for manufacturing carbon black and a furnace black process contained in the reaction furnace. The reactor of the present invention is adapted to enhance the mixing of combustion air and fuel in the combustion chamber to enhance the fuel combustion efficiency and produce high temperature combustion gases in the temperature range of 1000-. These high temperature combustion gases are then reacted with a hydrocarbon feedstock in a reaction chamber to obtain carbon black. The invention can improve the carbon black yield by 20%.

Referring to FIG. 1, there is illustrated a carbon black reactor furnace of the present invention, the reactor furnace being generally designated by the numeral 100 in FIG. 1. The reactor 100 comprises: a combustion chamber 102 having a fuel burner 106, an air inlet 108 and a flow directing device 110; a reaction chamber 104, in the direction of the longitudinal flow axis of the reactor 100, after the combustion chamber 102. In the combustion chamber 102, a hydrocarbon fuel such as fuel oil or natural gas is combusted in the presence of excess oxygen, typically provided as a flow of air, referred to herein as combustion gas, to produce high temperature combustion gases. In the combustion chamber 102, the fuel burner head 106 is located on the operative longitudinal axis of the reactor 100, and the air inlet 108 is generally perpendicular to the fuel burner head 106. Combustion air enters the air inlet 108 and flows to the fuel burner head 106.

The flow directing device 110 is located in the combustion air flow path between the fuel burner 106 and the air inlet 108. The flow directing means 110 is located on the effective longitudinal axis of the reactor 100, near the fuel burner head 106 rather than the gas inlet 108. Combustion air entering the air intake 108 follows a flow path labeled 112 in FIG. 1. The flow directing device 110 alters the flow path 112 of the combustion air before contacting the fuel at the fuel burner 106. Due to the modification of the combustion gas flow path 112, the mixing between the fuel and the combustion air is enhanced, thereby improving the fuel combustion efficiency and obtaining higher temperature combustion gas, typically in the temperature range of 1000-. The flow guide 110 further assists in stabilizing the flame of the fuel burner head 106 and maintaining the flame on the longitudinal axis of the reactor 100 for efficient operation. This helps to increase the life of the refractory lining 114 of the reactor 100.

The flow directing device 110 is at least one selected from the group consisting of a uniform annular cylinder, a tapered annular cylinder, a diaphragm, a vane, and the like. The flow directing device 110 may be a set of annular cylinders (as shown in fig. 1) or a set of tapered annular cylinders (not shown). In addition, these annular cylinders may be provided with a plurality of partitions, vanes or fins on the side wall along the length of the cylinder, as shown schematically in FIG. 2. For multiple annular cylinders (whether tapered or uniform), multiple vanes or vanes may also be provided in the innermost annular cylinder. Referring to fig. 2, various different forms of the flow guiding device 110 are shown in fig. 2a, 2b, 2c and 2f, wherein vanes or vanes 204 are located within an annular cylinder 202. The blade/vane 204 is illustrated in fig. 2d and 2 e.

Due to the flow guiding device 110, the temperature of the obtained high temperature combustion gas is increased. The high temperature combustion gas passes through the reaction furnace 100 from the combustion chamber 102 to the reaction chamber 104. In the reaction chamber 104, these gases react with the carbon-based feedstock to produce carbon black. The carbon black production can be increased by 5-20% using the flow directing device 110. The reactor of the present invention and the process therein are suitable for making hard or soft black grade carbon blacks.

Test results

The invention will now be described by the following examples, which are not intended to limit the scope of the invention in any way, but are merely exemplary of the invention.

Example 1:

table 1: comparative analysis was performed on the furnace black process with and without the flow guide 110.

According to Table 1, the carbon black production was increased by 5.75% using the flow guide 110, compared to the case where the flow guide was not used and the raw material flow rate was 4100 kg/hr; the carbon black production increased by 14.94% compared to the case where no flow guide was used and the raw material flow rate was 3700 kg/hr. Furthermore, the use of the flow guiding device 110 will also reduce the fuel consumption.

Example 2:

table 2: comparative analysis was performed on the furnace black process with and without the flow guide 110.

According to Table 2, the carbon black production increased 9.195% using the flow directing device 110 compared to the case where no flow directing device was used and the feedstock flow rate was 4350 kg/hr; the carbon black production was increased by 13.09% as compared to the case where no flow guide was used and the raw material flow rate was 4200 kg/hr. Furthermore, the use of the flow guiding device 110 will also reduce the fuel consumption.

Technical advantages

According to the invention, a reactor for carbon black manufacture comprises a flow directing device located between a fuel burner and an air inlet on the operative longitudinal axis of said reactor, adapted to alter the flow path of combustion air into the air inlet to better mix the fuel and combustion air and increase the temperature of the high temperature combustion gases subsequently received by the reaction chamber for reaction with a carbon-based feedstock to produce carbon black; the reactor and process described in the present invention have several technical advantages, including but not limited to:

● compared with a reactor without a flow guide device, the reactor of the invention can improve the carbon black output by 5-20%;

● the addition of the flow directing means further helps to stabilize the flame at the fuel burner by maintaining the orientation of the reactor in the longitudinal axis of effective operation, thereby extending the life of the reactor refractory lining;

● the flow rate of the raw material is increased by 5-20% compared with a reactor without flow guide device.

The numerical values recited for each physical parameter, dimension, or quantity are merely estimates, and it is contemplated that values above and below the assigned numerical value for the parameter, dimension, or quantity are within the scope of the invention unless otherwise expressly stated in the specification. In the case of a specified range of values, values below the minimum value and 10% above the maximum value of the specified range are included in the scope of the invention.

In view of the wide variety of specific implementations that can be used for the principles of the present invention, it should be understood that the illustrations are provided for exemplary purposes only. While considerable emphasis has been placed herein on the particular features of the invention, it will be appreciated that various changes can be made and that many changes can be made in the preferred embodiments without departing from the inventive principles. These and other modifications of the invention or preferred implementations will be apparent to those skilled in the art from the disclosure herein, and it is to be clearly understood that this description is made only by way of illustration and not as a limitation of the invention.

Claims (7)

1. A reactor for making carbon black using a furnace black process, the reactor comprising:

■, for generating hot combustion gases, said combustion chamber consisting of:

● a fuel burner located on the operative longitudinal axis of the reactor;

● an air inlet perpendicular to the fuel burner for receiving combustion air;

● located on the effective longitudinal axis of the reactor, near the fuel burner and intermediate the fuel burner and the air inlet, and thus in the path of the combustion air flow to change the flow path;

● is located on the operative longitudinal axis of the furnace after the combustion chamber, the reaction chamber being adapted to receive high temperature combustion gases from the combustion chamber and a carbon-based feedstock to form carbon black.

2. A reactor as claimed in claim 1 wherein the flow directing means is a set of annular cylinders.

3. A reactor as claimed in claim 1 wherein the flow directing means is a set of tapered annular cylinders.

4. The reactor as claimed in claim 1, wherein the flow guiding means is at least one selected from the group consisting of a uniform annular cylinder, a tapered annular cylinder, a baffle, a vane, a fin and the like.

5. A reactor as claimed in claim 1 wherein the flow directing means is a set of annular cylinders and at least one means selected from baffles, vanes and fins is disposed along the effective operating length of the cylinders.

6. The process for making carbon black comprises the steps of:

■ burning the fuel in a fuel burner located on the longitudinal axis of the effective operation of the reactor to produce carbon black;

■ receive combustion air through air inlets perpendicular to the fuel burner;

■ changing the flow path of the combustion air by means of flow guides on the effective longitudinal axis of the reactor, between the fuel burner and the air inlet, near the fuel burner;

■ to create efficient mixing between combustion air and fuel within the combustion chamber to produce high temperature combustion gases at temperatures between 1000 ℃ and 2200 ℃;

■ receive high temperature combustion gases in the reaction chamber after the combustion chamber on the operative longitudinal axis of the furnace and feed carbon-based feedstock to produce carbon black.

7. A process as claimed in claim 6, including the step of producing a grade of carbon black selected from the group of grades consisting of hard black to soft black.