Reactor device and method for increasing the concentration of light-burned magnesium oxide

Abstract

A reactor device and method for increasing the concentration of light-burned magnesium oxide, the device comprises a decomposition furnace, a transition pipeline, a separator, a kiln tail exhaust pipe and an air lock. The method is as follows: tertiary air and fuel are introduced into the decomposition furnace and the fuel is ignited. When the temperature in the decomposition furnace rises to 600°C, magnesite powder is fed into the decomposition furnace; the fuel combustion product in the decomposition furnace and the magnesite powder are subjected to gas-solid heat exchange. When the magnesite powder and the exhaust gas in the decomposition furnace reach the design temperature and the feeding amount, the exhaust gas stays in the decomposition furnace for 2 to 3 seconds, and the material stays in the decomposition furnace for 2 to 20 seconds, until the material decomposition rate reaches more than 92%; the gas-solid mixture after gas-solid heat exchange in the decomposition furnace enters the separator through the transition pipeline, and the exhaust gas at the kiln tail also enters the separator through the exhaust pipe at the kiln tail and the transition pipeline in turn, and the gas-solid mixture is separated by the separator, and the separated solid material is fed into the feeding port at the kiln tail through the air lock, and the separated gas enters the next process through the exhaust port.

Description

Technical Field

[0001] The invention belongs to the technical field of inorganic non-metallic material processing, and in particular relates to a reactor device and a method for increasing the concentration of light-burned magnesium oxide. Background Art

[0002] Lightly burned magnesium oxide is one of the important basic raw materials. At present, the main production technology used is "decomposition outside the kiln + rotary kiln". The heat source used by the decomposition furnace is partly fuel and the combustion products of the tertiary air from the kiln head, and the other part comes from the exhaust gas at the end of the kiln. The tertiary air enters from the cone air inlet of the decomposition furnace to assist combustion, and the exhaust gas at the end of the kiln enters from the cone entrance of the decomposition furnace. However, since the temperature of the exhaust gas at the end of the kiln is less than 600℃ and the oxygen content is low, it cannot be used for the combustion of fuel, nor can it reach the decomposition temperature of magnesite. The only way is to increase the specifications of the decomposition furnace, resulting in a low unit volume capacity of the decomposition furnace. In addition, since a large amount of solid particles carried by the exhaust gas at the end of the kiln will pass through the high-temperature combustion zone at the bottom of the decomposition furnace, this part of the material will be overburned, resulting in reduced product activity and affecting product quality. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention provides a reactor device and method for increasing the concentration of light-burned magnesium oxide, which has the characteristics of improving product activity, reducing equipment specifications, increasing the solid content in the furnace, increasing system production capacity, reasonably distributing heat, and improving the thermal utilization rate of the decomposition furnace.

[0004] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a reactor device for increasing the concentration of light-burned magnesium oxide, comprising a decomposition furnace, a transition pipeline, a separator, a kiln tail exhaust pipe and an air lock; a feed port is arranged in the middle of the decomposition furnace, a fuel inlet and a tertiary air inlet are respectively arranged at the bottom of the decomposition furnace, and a discharge port is arranged at the top of the decomposition furnace; a feed port and an exhaust port are respectively arranged at the top of the separator; the discharge port at the top of the decomposition furnace and the exhaust port at the top of the separator are connected through a transition pipeline; the lower end of the kiln tail exhaust pipe is the kiln tail exhaust inlet, the upper end of the kiln tail exhaust pipe is the kiln tail exhaust outlet, and the kiln tail exhaust outlet at the upper end of the kiln tail exhaust pipe is connected to the transition pipeline; a discharge port is arranged at the bottom of the separator, and the discharge port at the bottom of the separator is connected to the kiln tail feeding port through an air lock.

[0005] The height-to-diameter ratio of the decomposition furnace is ≤4, the number of feed inlets of the decomposition furnace is 2-3, the multiple feed inlets are located in the same horizontal cross section and are evenly distributed along the circumferential direction of the decomposition furnace.

[0006] The number of fuel inlets of the decomposition furnace is multiple and ≤12, and the multiple fuel inlets are in the same horizontal cross section and are evenly distributed along the circumferential direction of the decomposition furnace.

[0007] A method for increasing the concentration of light-burned magnesium oxide, using the reactor device for increasing the concentration of light-burned magnesium oxide, comprises the following steps:

[0008] Step 1: Continuously introduce tertiary air into the decomposition furnace from the tertiary air inlet, and continuously introduce fuel into the decomposition furnace from the fuel inlet and ignite it. When the temperature in the decomposition furnace rises to 600°C, gradually feed magnesite powder into the decomposition furnace from the feed inlet;

[0009] Step 2: In the decomposition furnace, the fuel combustion products continue to exchange gas-solid heat with the magnesite powder. When the magnesite powder and the exhaust gas in the decomposition furnace reach the designed temperature and feed rate, the exhaust gas stays in the decomposition furnace for 2 to 3 seconds, and the material stays in the decomposition furnace for 2 to 20 seconds, until the material decomposition rate reaches more than 92%;

[0010] Step 3: The gas-solid mixture after gas-solid heat exchange in the decomposition furnace enters the separator through the transition pipe. At the same time, the exhaust gas from the kiln tail passes through the exhaust gas pipe and the transition pipe in sequence and enters the separator. The separator separates the gas-solid mixture into gas and solid. The separated solid material is fed into the feeding port of the kiln tail through the air lock, and the separated gas enters the next process through the exhaust port.

[0011] The temperature of the tertiary air introduced into the decomposition furnace is 270-320°C, and the air inlet velocity is 20-60m / s.

[0012] The design temperature of the exhaust gas in the decomposition furnace is 800-850℃.

[0013] The temperature of the kiln tail exhaust gas entering the separator is 550-600℃, and the kiln tail exhaust gas volume is 460Nm 3 / t·product, the air flow velocity in the exhaust pipe at the kiln tail is 16~22m / s.

[0014] The solid material separation efficiency of the separator is ≥96%.

[0015] Beneficial effects of the present invention:

[0016] Compared with the existing production technology of the same scale and using natural gas as fuel, the reactor device of the present invention can reduce the diameter of the decomposition furnace by 1 / 6, reduce the height of the decomposition furnace by 1 / 6, and reduce the volume of the decomposition furnace by more than 40%. The concentration of light-burned magnesium oxide is increased from the original 125g / m 3 Increased to 200 g / m 3 The above greatly improves the production capacity of the decomposition furnace.

[0017] Compared with the existing production technology of the same scale using natural gas as fuel, the reactor device of the present invention for increasing the concentration of light-burned magnesium oxide can prevent a large amount of particulate matter entrained in the kiln tail exhaust gas from passing through the high-temperature combustion zone through a separately arranged kiln tail exhaust pipe, thereby preventing overburning and reducing the product activity value from the original more than 90s (citric acid colorimetric method) to less than 50s.

[0018] Compared with the existing production technology of the same scale using natural gas as fuel, the reactor device for increasing the concentration of light-burned magnesium oxide of the present invention can greatly increase the contact opportunity between SO3 and magnesium oxide when the concentration of light-burned magnesium oxide in the decomposition furnace is increased, thereby effectively reducing the emission of SO3 in the exhaust gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a reactor device for increasing the concentration of light-burned magnesium oxide according to the present invention;

[0020] In the figure, 1 is the decomposition furnace, 2 is the transition duct, 3 is the separator, 4 is the exhaust pipe at the kiln tail, 5 is the air lock, A is the feed inlet, B is the fuel inlet, C is the tertiary air inlet, D is the exhaust gas inlet at the kiln tail, E is the feed inlet at the kiln tail, and F is the exhaust port. Implementation

[0021] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1 As shown, a reactor device for increasing the concentration of light-burned magnesium oxide comprises a decomposition furnace 1, a transition pipe 2, a separator 3, a kiln tail exhaust pipe 4 and an air lock 5; a feed port A is arranged in the middle of the decomposition furnace 1, a fuel inlet B and a tertiary air inlet C are arranged at the bottom of the decomposition furnace 1, and a discharge port is arranged at the top of the decomposition furnace 1; a feed port and an exhaust port F are arranged at the top of the separator 3; the discharge port at the top of the decomposition furnace 1 is connected with the exhaust port F at the top of the separator 3 through a transition pipe 2; the lower end of the kiln tail exhaust pipe 4 is a kiln tail exhaust inlet D, and the upper end of the kiln tail exhaust pipe 4 is a kiln tail exhaust outlet, and the kiln tail exhaust outlet at the upper end of the kiln tail exhaust pipe 4 is connected with the transition pipe 2; a discharge port is arranged at the bottom of the separator 3, and the discharge port at the bottom of the separator 3 is connected with the kiln tail feeding port E through an air lock 5.

[0023] The height-to-diameter ratio of the decomposition furnace 1 is ≤4, the number of feed inlets A of the decomposition furnace 1 is 2-3, and the multiple feed inlets A are located in the same horizontal cross section and are evenly distributed along the circumference of the decomposition furnace 1.

[0024] The number of the fuel inlets B of the decomposition furnace 1 is multiple and ≤ 12, and the multiple fuel inlets B are in the same horizontal section and evenly distributed along the circumference of the decomposition furnace 1. Specifically, the number of the fuel inlets B is preferably a number divisible by 360.

[0025] A method for increasing the concentration of light-burned magnesium oxide, using the reactor device for increasing the concentration of light-burned magnesium oxide, comprises the following steps:

[0026] Step 1: continuously introduce tertiary air into the decomposition furnace 1 from the tertiary air inlet C, and continuously introduce fuel into the decomposition furnace 1 from the fuel inlet B and ignite it. When the temperature in the decomposition furnace 1 rises to 600°C, gradually feed magnesite powder into the decomposition furnace 1 from the feed inlet A; wherein the temperature of the tertiary air introduced into the decomposition furnace 1 is 270-320°C, and the air intake speed is 20-60m / s;

[0027] Step 2: In the decomposition furnace 1, the fuel combustion products continue to exchange gas and solid with the magnesite powder. When the magnesite powder and the exhaust gas in the decomposition furnace 1 reach the design temperature and feed rate, the exhaust gas stays in the decomposition furnace 1 for 2 to 3 seconds, and the material stays in the decomposition furnace 1 for 2 to 20 seconds, until the material decomposition rate reaches more than 92% (mass ratio); wherein, the design temperature of the exhaust gas in the decomposition furnace 1 is 800 to 850°C; the temperature of the exhaust gas at the kiln tail entering the separator 3 is 550 to 600°C, and the exhaust gas volume at the kiln tail is 460Nm 3 / t·product, the air flow velocity in the exhaust pipe 4 at the kiln tail is 16-22m / s;

[0028] Step 3: The gas-solid mixture after gas-solid heat exchange in the decomposition furnace 1 enters the separator 3 through the transition pipe 2, and the kiln tail exhaust gas also enters the separator 3 through the kiln tail exhaust pipe 4 and the transition pipe 2 in sequence. The gas-solid mixture is separated by the separator 3, and the separated solid material is fed into the kiln tail feeding port E through the air lock 5, and the separated gas enters the next process through the exhaust port F; wherein, the separation efficiency of the solid material of the separator 3 is ≥96%.

[0029] The solutions in the embodiments are not intended to limit the patent protection scope of the present invention. All equivalent implementations or changes that do not deviate from the present invention are included in the patent scope of this case.

Claims

1. A reactor device for increasing the concentration of light-burned magnesium oxide, characterized in that: It includes a decomposition furnace, a transition pipeline, a separator, a kiln tail exhaust pipe and an air lock; a feed port is arranged in the middle of the decomposition furnace, a fuel inlet and a tertiary air inlet are respectively arranged at the bottom of the decomposition furnace, and a discharge port is arranged at the top of the decomposition furnace; a feed port and an exhaust port are respectively arranged at the top of the separator; the discharge port at the top of the decomposition furnace and the exhaust port at the top of the separator are connected through a transition pipeline; the lower end of the kiln tail exhaust pipe is the kiln tail exhaust inlet, the upper end of the kiln tail exhaust pipe is the kiln tail exhaust outlet, the kiln tail exhaust outlet at the upper end of the kiln tail exhaust pipe is connected with the transition pipeline, and the particulate matter entrained by the kiln tail exhaust gas does not pass through the high-temperature combustion zone through the separately arranged kiln tail exhaust pipe; a discharge port is arranged at the bottom of the separator, and the discharge port at the bottom of the separator is connected with the kiln tail feeding port through an air lock.

2. A reactor device for increasing the concentration of light-burned magnesium oxide according to claim 1, characterized in that: The height-to-diameter ratio of the decomposition furnace is ≤4, the number of feed inlets of the decomposition furnace is 2-3, the multiple feed inlets are located in the same horizontal cross section and are evenly distributed along the circumferential direction of the decomposition furnace.

3. A reactor device for increasing the concentration of light-burned magnesium oxide according to claim 1, characterized in that: The number of the fuel inlets of the decomposition furnace is multiple and ≤12, and the multiple fuel inlets are in the same horizontal cross section and are evenly distributed along the circumferential direction of the decomposition furnace.

4. A method for increasing the concentration of light-burned magnesium oxide, using the reactor device for increasing the concentration of light-burned magnesium oxide according to claim 1, characterized in that The steps include: Step 1: Continuously introduce tertiary air into the decomposition furnace from the tertiary air inlet, and continuously introduce fuel into the decomposition furnace from the fuel inlet and ignite it. When the temperature in the decomposition furnace rises to 600°C, gradually feed magnesite powder into the decomposition furnace from the feed inlet; Step 2: In the decomposition furnace, the fuel combustion products continue to exchange gas-solid heat with the magnesite powder. When the magnesite powder and the exhaust gas in the decomposition furnace reach the designed temperature and feed rate, the exhaust gas stays in the decomposition furnace for 2 to 3 seconds, and the material stays in the decomposition furnace for 2 to 20 seconds, until the material decomposition rate reaches more than 92%; Step 3: The gas-solid mixture after gas-solid heat exchange in the decomposition furnace enters the separator through the transition pipe. At the same time, the exhaust gas from the kiln tail passes through the exhaust gas pipe and the transition pipe in sequence and enters the separator. The separator separates the gas-solid mixture into gas and solid. The separated solid material is fed into the feeding port of the kiln tail through the air lock, and the separated gas enters the next process through the exhaust port.

5. A method for increasing the concentration of light-burned magnesium oxide according to claim 4, characterized in that: The temperature of the tertiary air introduced into the decomposition furnace is 270-320°C, and the air inlet velocity is 20-60m / s.

6. A method for increasing the concentration of light-burned magnesium oxide according to claim 4, characterized in that: The design temperature of the exhaust gas in the decomposition furnace is 800-850℃.

7. A method for increasing the concentration of light-burned magnesium oxide according to claim 4, characterized in that: The temperature of the kiln tail exhaust gas entering the separator is 550-600℃, and the kiln tail exhaust gas volume is 460Nm 3 / t·product, the air flow velocity in the exhaust pipe at the kiln tail is 16~22m / s.

8. A method for increasing the concentration of light-burned magnesium oxide according to claim 4, characterized in that: The separation efficiency of the solid material in the separator is ≥96%.

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