Upright furnace pyrolysis system with external heat source

Abstract

The utility model provides a vertical furnace pyrolysis system with an external heat source, which comprises a combustion-supporting gas mechanism, a combustion furnace, a vertical furnace mechanism and a coal gas cooling mechanism which are sequentially communicated, and the coal gas cooling mechanism is respectively communicated with the combustion furnace and an output pipeline through pipelines. According to the utility model, the external combustion furnace is adopted, and the heat recycle gas generated by the combustion of the surplus coal gas in the combustion furnace is used as the heat carrier of the raw coal pyrolysis in the vertical furnace, so that the heat source of the method is stable, the raw coal dry distillation temperature is stable, and the problems that the combustion temperature in the furnace is difficult to control and the semi-coke is burnt out are solved; the problems of slag bonding in the furnace, unstable quality of semi-coke products and the like are effectively avoided; oxygen-enriched air is adopted as a combustion-supporting substance, invalid components in by-product gas components are effectively reduced, the content of effective components is increased, and therefore the calorific value and the utilization value of the gas are increased.

Description

Technical Field

[0001] The utility model belongs to the technical field of low-temperature pyrolysis of coal chemical industry, and in particular relates to a heat source external vertical furnace pyrolysis system. Background Art

[0002] my country is rich in low-grade coal resources. Low-temperature pyrolysis is an effective method for the fractional utilization of low-grade coal to obtain coal gas, semi-coke and tar. At present, the main method for producing semi-coke from low-grade coal is the internal combustion and internal heating vertical carbonization furnace pyrolysis process: lump coal is added from the top of the furnace, air is used as the oxygen source, and coal gas and air are blown into the lower part of the furnace for combustion. The high-temperature gas generated moves in the opposite direction of the lump coal in the furnace to achieve heat exchange and low-temperature pyrolysis (temperature is generally below 750°C). The mixed gas after pyrolysis is led out of the furnace, and the coal tar and coal gas are recovered after washing and purification.

[0003] Although the semi-coke produced by this process technology is stable and reliable, it also brings some problems in the subsequent gas purification and comprehensive utilization process. First, due to the use of internal combustion and internal hot air combustion-assisted heating method, the combustion flue gas is mixed with the gas produced by the pyrolysis of the raw coal, and the gas out of the furnace contains a large amount of nitrogen, which not only increases the processing pressure of the gas purification system, but also reduces the calorific value of the gas, which has a great impact on the subsequent high-value-added processing and utilization of the gas, and it is difficult to meet industrial or civil requirements; second, due to the combustion reaction in the furnace, not only the semi-coke is burned, but also the high temperature generated by the combustion is not well controlled, which affects the normal operation of the furnace. If the temperature is too high, it is easy to cause coking and blocking the furnace, so that the vertical furnace cannot operate normally. When coking occurs, it is not only difficult to handle, the labor intensity is high, but also causes downtime losses; if the temperature is too low, it may cause incomplete distillation, affecting the quality and output of semi-coke products. Utility Model Content

[0004] The purpose of the utility model is to provide a heat source external vertical furnace pyrolysis system to overcome the above technical problems existing in the prior art.

[0005] To this end, the technical solution provided by the utility model is as follows:

[0006] A heat source external vertical furnace pyrolysis system comprises a combustion-supporting mechanism, a combustion furnace, a vertical furnace mechanism and a gas cooling mechanism which are connected in sequence. The gas cooling mechanism is connected to the combustion furnace and an external transmission pipeline through pipelines.

[0007] The combustion-supporting mechanism comprises an oxygen-generating device, an air blower and a mixer. The oxygen-generating device and the air blower are both connected to the mixer through a connecting pipeline, and a proportional regulating valve is provided on the connecting pipeline.

[0008] The vertical furnace mechanism comprises a furnace top silo, a vertical furnace and a coke removal device under the furnace. The furnace top silo is arranged on the top of the vertical furnace and connected thereto, and the lower part of the vertical furnace is connected to the coke removal device under the furnace.

[0009] The coal gas cooling mechanism comprises a gas collecting tank, a direct cooling tower, an intercooler, an electric tar collector and a blower. The gas collecting tank is connected to the direct cooling tower, and the intercooler is connected to the blower.

[0010] The air outlet of the combustion furnace is provided with a water-cooled hot air valve.

[0011] The beneficial effects of the utility model are:

[0012] The utility model adopts an external combustion furnace, and uses the hot circulating gas generated by the combustion of surplus coal gas in the combustion furnace as a heat carrier for pyrolysis of raw coal in a vertical furnace. The method has a stable heat source and a stable raw coal dry distillation temperature, solves the problems of difficult control of the combustion temperature in the furnace and burning loss of semi-coke, and effectively avoids slagging in the furnace and unstable semi-coke product quality. Oxygen-enriched air is adopted as a combustion-supporting substance, which effectively reduces the invalid components in the by-product coal gas components and increases the content of the effective components, thereby improving the calorific value and utilization value of the coal gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of an implementation method of the utility model.

[0014] In the figure: 1. Oxygen production equipment; 2. Air blower; 3. Mixer; 4. Combustion furnace; 5. Vertical furnace mechanism; 6. Gas cooling mechanism. DETAILED DESCRIPTION

[0015] The following is an explanation of the implementation of the present invention by means of specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0016] The exemplary embodiments of the present invention are now introduced with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0017] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0018] Example 1

[0019] The utility model provides a heat source external vertical furnace pyrolysis system, such as Figure 1 As shown, it includes a combustion-supporting mechanism, a combustion furnace 4, a vertical furnace mechanism 5 and a gas cooling mechanism 6 which are connected in sequence. The gas cooling mechanism 6 is connected to the combustion furnace 4 and the external transmission pipeline through pipelines.

[0020] Working principle:

[0021] The combustion-supporting gas and the return gas enter the combustion furnace 4 for combustion, and the generated heat source (called hot circulating gas) is sent to the vertical furnace mechanism 5 for pyrolysis of the raw coal. The dry distillation gas generated by pyrolysis is mixed with the hot circulating gas and then led out of the furnace and sent to the gas cooling mechanism 6. A part of the cooled and purified gas returns to the combustion furnace 4 for combustion, and the remaining part is sent out through an external transmission pipeline. Among them, the return gas volume of the combustion furnace 4 includes the volume of completely burned gas and the volume of gas used for cooling. By adjusting the ratio of the return gas volume to the combustion-supporting gas volume, the temperature of the circulating gas after combustion can be adjusted to ensure the heat requirement for pyrolysis in the vertical furnace.

[0022] The utility model adopts an external combustion furnace 4, and the heat supply is controllable and adjustable, which can ensure the stability of the vertical furnace heat supply, avoid slagging in the furnace, and effectively improve the product quality; compared with the existing internal combustion and internal heating vertical furnace pyrolysis, the utility model is conducive to balancing the temperature in the furnace, avoiding the burning of blue charcoal and slagging in the furnace, and improving the service life of the furnace. The combustion-supporting combustion mechanism can adjust the combustion-supporting combustion composition, and the oxygen ratio ranges from 21% to 90%, effectively reducing the N in the gas after combustion. 2 content, improving the calorific value and utilization value of gas.

[0023] Example 2

[0024] On the basis of Example 1, this embodiment provides a heat source external vertical furnace pyrolysis system, the combustion-supporting mechanism includes an oxygen production device 1, an air fan 2 and a mixer 3, the oxygen production device 1 and the air fan 2 are connected to the mixer 3 through a connecting pipeline, and a proportional regulating valve is provided on the connecting pipeline.

[0025] The oxygen in the oxygen-rich part of the combustion-supporting gas is provided by the oxygen generator 1, and the air part in the combustion-supporting gas is provided by the air blower 2. The combustion-supporting gas can be provided by mixing air and oxygen in the pipeline mixer 3 according to the process requirements. The volume fraction of oxygen in the combustion-supporting gas is 21%-90%, and the specific ratio is adjusted according to the requirements. Increasing the oxygen content in the combustion-supporting gas can reduce the content of the ineffective component nitrogen in the combustion gas, thereby increasing the calorific value of the coal gas.

[0026] When the combustion-supporting gas is mainly provided by oxygen, that is, the oxygen ratio is above 90%, in order to ensure that the combustion furnace 4 supplies the heat required by the vertical furnace, the amount of recycled gas needs to be changed accordingly.

[0027] Example 3

[0028] Based on Example 1, this embodiment provides a vertical furnace pyrolysis system with an external heat source, wherein the vertical furnace mechanism 5 includes a furnace top silo, a vertical furnace and an under-furnace coke removal device, wherein the furnace top silo is disposed at the top of the vertical furnace and connected thereto, and the lower part of the vertical furnace is connected to the under-furnace coke removal device.

[0029] The vertical furnace has no restrictions on specifications and sizes, and can be used for the corresponding semi-coke production of 100,000 tons / year, 150,000 tons / year, 200,000 tons / year and higher production. The vertical furnace adopts the design of built-in combustion chamber, full material cavity, and reverse direct heat exchange. A hot circulating gas inlet is set in the middle and lower part of the vertical furnace; the dry distillation temperature range of the vertical furnace is 500℃-750℃; the original fire channel of the vertical furnace is changed to a hot circulating gas channel.

[0030] The heat source external vertical furnace pyrolysis system does not require major modifications to the main structure of the vertical furnace. It only needs to remove the burner and transform the return gas channel in the furnace into a hot circulation gas channel. The equipment is simple, the risk is small, and the investment in new construction and transformation is small. Among them, the hot circulation gas channel is evenly distributed according to the gas volume to ensure uniform gas distribution.

[0031] Example 4

[0032] Based on Example 1, this example provides a heat source external vertical furnace pyrolysis system, wherein the coal gas cooling mechanism 6 includes a gas collecting tank, a direct cooling tower, an intercooler and a blower, wherein the gas collecting tank is connected to the direct cooling tower, and the intercooler is connected to the blower.

[0033] The outlet gas of the vertical furnace is cooled by a direct cooling tower and an intercooler.

[0034] Example 5

[0035] On the basis of Example 1, this embodiment provides a pyrolysis system with a vertical furnace having an external heat source, wherein the air outlet of the combustion furnace 4 is provided with a water-cooled hot air valve.

[0036] The water-cooled hot air valve has a water tank and cooling water inside to reduce the temperature of the valve body and prevent malfunctions caused by excessive heat. The amount of hot circulating air is adjusted by the water-cooled hot air valve.

[0037] In summary, the utility model has the following characteristics: 1. The external combustion type adopts oxygen-enriched combustion, which can reduce the invalid components in the by-product gas composition and improve the calorific value and utilization rate; 2. It can continuously and stably supply the vertical furnace with a dry distillation heat carrier at a temperature of about 800°C, and the oxygen content in the heat carrier is lower than the safety limit of 1%, so that the pyrolysis process and the device can operate safely and stably; 3. The heat provided by the heat carrier can meet the heat needs of the vertical furnace, so that the raw coal can be completely dry distilled; 4. There is no burning loss of the semi-coke in the vertical furnace, and the product quality and quantity are guaranteed. The utility model has a simple structure, convenient operation, safety and reliability. It solves the problems of high useless components and low calorific value of the by-product gas in the existing semi-coke production process and the combustion reaction in the furnace affecting the production and product quality, and improves the quality of the by-product gas and the quality of the semi-coke product.

[0038] The above examples are merely illustrative of the present invention and do not constitute a limitation on the protection scope of the present invention. All designs that are identical or similar to the present invention fall within the protection scope of the present invention.

Claims

1. A heat source external vertical furnace pyrolysis system, characterized in that: The invention comprises a combustion-supporting mechanism, a combustion furnace, a vertical furnace mechanism and a gas cooling mechanism which are connected in sequence. The gas cooling mechanism is connected to the combustion furnace and an external transmission pipeline respectively through pipelines.

2. The heat source external vertical furnace pyrolysis system according to claim 1, characterized in that: The combustion-supporting mechanism comprises an oxygen-generating device, an air blower and a mixer. The oxygen-generating device and the air blower are both connected to the mixer through a connecting pipeline, and a proportional regulating valve is provided on the connecting pipeline.

3. The external heat source vertical furnace pyrolysis system according to claim 1, characterized in that: The vertical furnace mechanism comprises a furnace top silo, a vertical furnace and a coke removal device under the furnace. The furnace top silo is arranged on the top of the vertical furnace and connected thereto, and the lower part of the vertical furnace is connected to the coke removal device under the furnace.

4. The heat source external vertical furnace pyrolysis system according to claim 1, characterized in that: The coal gas cooling mechanism comprises a gas collecting tank, a direct cooling tower, an intercooler, an electric tar collector and a blower. The gas collecting tank is connected to the direct cooling tower, and the intercooler is connected to the blower.

5. The heat source external vertical furnace pyrolysis system according to claim 1, characterized in that: The air outlet of the combustion furnace is provided with a water-cooled hot air valve.

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