Thermodynamic system suitable for recovering waste heat of calcined coke of carbon calcining furnace

Abstract

The utility model provides a thermodynamic system suitable for recovering waste heat of calcined coke of a carbon calcining furnace. The thermodynamic system comprises a steam pocket, an ancillary facility subunit of the steam pocket, a steam-generating water jacket subunit, a steam collecting subunit and a water supply deoxygenation subunit, the steam-water producing jacket unit consists of a descending pipe, a circulating pump, a steam-water producing jacket group and an ascending pipe; the steam collecting subunit is composed of a steam pocket outlet steam pipeline, a steam collecting box and a steam leading-out pipeline. The water supply and deoxygenation subunit is composed of a deoxygenation steam pipeline, a deaerator, an external water replenishing pipeline, a steam pocket water supply pipeline and a water supply pump; according to the utility model, the calcined coke of the calcining furnace can be safely cooled, so that the steam-water-producing jacket group is safely and stably operated; compared with the traditional mode, the steam is produced by using the heat of the calcined coke, so that the economical efficiency is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of waste heat utilization, and more specifically to a thermal system suitable for recovering waste heat from calcined coke in a carbon calcining furnace. Background Art

[0002] The aluminum carbon industry generally uses a pot calciner to process petroleum coke into prebaked anodes, which are used as anode materials in the aluminum smelting process of the electrolytic aluminum industry. Petroleum coke is calcined at high temperature in a pot calciner to remove moisture, volatiles and other chemical residues, increase the density and mechanical strength of the raw materials, and enhance the conductivity. Then, it is crushed, kneaded, roasted and other processes to form prebaked anodes.

[0003] The pot calcining furnace is a type of furnace widely used in the aluminum carbon industry. During calcination, the raw materials are added to the pot by the charging device on the top of the furnace. During the movement from top to bottom, they are gradually heated by the fire channels on both sides of the pot. When the raw materials are heated to 350-600℃, a large amount of volatiles are released. They are collected through the volatile channel and sent to the fire channel for combustion. The combustion of volatiles is another source of heat for the pot calcining furnace. After the raw materials undergo a series of physical and chemical changes at a high temperature of more than 1200-1300℃, they become calcined coke. The calcined coke enters the water jacket arranged below from the bottom of the pot for cooling, and is finally discharged from the furnace by the discharge device. The calcining furnace is composed of many pots, generally 4 pots in a group. At present, the pot furnace has a trend of large-scale, with up to more than 20 groups of pots. Each pot has a feeding port on the top and a discharge port on the bottom, and the material moves slowly downward by gravity.

[0004] A water jacket is arranged under each material tank to cool the calcined coke. Currently, the most commonly used form of water jacket is the jacketed heat exchanger, which is a sandwich structure. The calcined coke passes through the space surrounded by the inner wall of the sandwich, and cooling water flows between the inner wall and the outer wall of the sandwich.

[0005] The current characteristics of cooling calcined coke are as follows:

[0006] First, the calcination temperature is as high as 1200-1300℃. In the current production process, circulating water is generally used to cool the calcined coke through a jacketed heat exchanger, so that the material is discharged and collected after the temperature is below 100℃. The circulating water is heated and then cooled through a cooling tower for recycling. This method does not effectively utilize high-quality waste heat.

[0007] Second, each calcining furnace is composed of a large number of material tanks. For example, a well-known Shandong enterprise invested in a carbon project in Zhundong, Xinjiang, with an annual output of 300,000 tons of carbon, a total of 4 calcining furnaces, and each calcining furnace has 88 material tanks. Each tank discharge corresponds to a jacketed heat exchanger or the steam-water production set discussed in this patent. During production operation, the safe operation of each heat exchanger must be ensured.

[0008] Third, the calcination temperature is as high as 1200-1300℃, which places high demands on the safety of each cooling and heat exchange equipment. If the system design is improper, the equipment quality is not up to standard, or there are operating errors, the cooling and heat exchange equipment will be damaged due to local high temperature.

[0009] Whether it is a jacketed heat exchanger or the steam-water production set discussed in this patent, in order to ensure its safe operation, a key problem must be solved, that is, the cooling and heat exchange equipment must not be allowed to generate local high temperatures, which will cause high-temperature burning or even high-temperature carbonization of the cooling and heat exchange equipment and damage it. Therefore, first, the cooling and heat exchange equipment must be reasonably designed and have good manufacturing quality. Second, and more importantly, its supporting thermal system must be able to ensure effective operation. That is, after the calcined coke is discharged into the heat exchanger, no matter the fluctuation of the amount of calcined coke or the temperature change, no matter whether the working fluid state in each cooling and heat exchange equipment is water, steam or a mixture of steam and water, no matter whether the working fluid side pressure in each cooling and heat exchange equipment is balanced, it is necessary to ensure that the working fluid of each cooling and heat exchange equipment keeps flowing smoothly, and the working fluid needs to take away the heat of the calcined coke in time, so as to achieve the cooling purpose of the calcined coke and ensure the safe operation of the cooling and heat exchange equipment. Therefore, it can be seen that a safe and highly applicable waste heat recovery system is more important. Utility Model Content

[0010] In view of the above situation, the utility model patent provides a thermal system suitable for recovering waste heat from calcined coke in a carbon calcining furnace. The system can achieve high-quality recovery of waste heat while ensuring the safety of production operations. At the same time, the utility model can safely cool the calcined coke in the calcining furnace and enable the steam-water production set to operate safely and stably. Compared with traditional methods, the use of the heat from the calcined coke to produce steam greatly improves the economy.

[0011] Specifically, this utility model patent is realized through the following technical solutions:

[0012] A thermal system suitable for recovering waste heat from calcined coke in a carbon calcining furnace comprises a steam drum and its auxiliary facilities subunit, a steam-water jacket subunit, a steam collection subunit and a water supply deoxygenation subunit.

[0013] A thermal system suitable for recovering waste heat from coke after calcination in a carbon calcining furnace, the thermal system comprising a steam drum and its auxiliary facilities subunit, a steam-producing water jacket subunit, a steam collecting subunit and a water supply deoxygenation subunit; the steam-producing water jacket subunit is composed of a downcomer, a circulating pump, a steam-producing water jacket set and an ascending pipe; the steam collecting subunit is composed of a steam drum outlet steam pipeline, a steam header and a steam outlet pipeline; the water supply deoxygenation subunit is composed of a deoxygenated steam pipeline, a deaerator, an external water supply pipeline, a steam drum water supply pipeline and a water supply pump; wherein:

[0014] The steam drum sequentially inputs the hot water separated from the steam drum to the steam-water production set through the downcomer and the circulating pump; the output end of the steam-water production set re-transports the treated hot water to the steam drum through the upcomer;

[0015] The drum inputs the separated steam from the drum to the steam header through the drum outlet steam pipeline, and the steam header outputs the treated steam to the subsequent utilization equipment through the steam lead-out pipeline on one side; the other side of its output is connected to the deaerator through the deoxygenated steam pipeline; the output end of the deaerator delivers the deoxygenated hot water to the drum through the drum feed water pipeline and the feed water pump;

[0016] The feed water deoxygenation subunit provides feed water to the steam drum through an external feed water pipeline.

[0017] Beneficial Effects

[0018] 1. One steam drum can collect the steam generated by several calcined coke coolers, that is, the steam-water production sets. For large-scale carbon production lines, multiple steam drums can be set up.

[0019] 2. The steam header in the utility model can collect the steam generated by multiple steam drums and provide steam to the outside at the same time.

[0020] 3. The utility model is provided with a forced circulation pump, which can provide a strong power source for the steam-water production set. No matter what state the working medium in the steam-water production set is in, the working medium of the steam-water production set can be kept in a flowing state, and the heat of the calcined coke can be taken away in time, so as to avoid the local high temperature of the steam superheater and damage.

[0021] 4. The utility model is provided with a deoxygenation function through a water deoxygenation subunit, thereby reducing the possibility of high-temperature oxidation and extending the life of the system, equipment and pipelines.

[0022] 5. According to the number of calcining furnaces, the number of calcining furnace material tanks and the layout of the factory building, the number of steam drums should be reasonably set to reduce the number of steam-water production sets provided by each steam drum, which is conducive to ensuring the pressure balance of the steam-water production sets.

[0023] The above measures have greatly improved the safety performance of the thermal system for recovering waste heat from calcined coke in a carbon calcining furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a thermal system diagram of the utility model patent suitable for recovering waste heat from coke after calcination in a carbon calcining furnace.

[0025] Reference numerals:

[0026] 100. Steam drum and its auxiliary facilities subunit; 101. Steam drum;

[0027] 200, steam-water production subunit; 201, downcomer; 202, circulation pump; 203, steam-water production set; 204, riser;

[0028] 300, steam collecting subunit; 301, steam pipeline at drum outlet; 302, steam header; 303, steam pipeline at drum outlet;

[0029] 400, water deaerator subunit; 401, deaerator steam pipeline; 402, deaerator; 403, drum feed water pipeline; 404, feed water pump; 405, external water supply pipeline DETAILED DESCRIPTION

[0030] The utility model patent is further described below in conjunction with the accompanying drawings.

[0031] A thermal system suitable for recovering waste heat from calcined coke in a carbon calcining furnace has the main purposes of firstly recovering waste heat from calcined coke in a carbon calcining furnace to generate steam and secondly, further, providing guarantee conditions for the safe operation of a steam-water production unit by reasonably setting up the thermal system.

[0032] like Figure 1 As shown, a thermal system suitable for recovering waste heat from calcined coke in a carbon calcining furnace comprises a steam drum and its ancillary facilities subunit 100, a steam-water jacket subunit 200, a steam collection subunit 300 and a feed water deoxygenation subunit 400.

[0033] The steam drum and its auxiliary facilities subunit 100, the steam drum 101 is a horizontal tank. At the same time, the steam drum 101 is provided with auxiliary facilities such as a safety valve, a liquid level gauge, a pressure gauge, a thermometer, an exhaust pipe, and a sewage outlet, the purpose of which is to ensure the safe operation of the steam drum 101. The steam or steam-water mixture generated by the steam-water production set of calcined coke enters the steam drum for separation, and the steam is collected in the upper space of the steam drum 101, and the hot water is collected in the lower part of the steam drum 101. The steam in the upper space can be transported to the steam collection subunit 300, and the hot water in the lower space enters the steam-water production set subunit 200 again.

[0034] Furthermore, the steam-water jacket subunit 200 is used to transport water from the lower space of the drum to multiple steam-water jackets 203 after being pressurized by the downcomer 201 and the circulating pump 202. The circulating pump 202 is the most important equipment to ensure the safe operation of the steam-water jacket, and is also the most important technical point of the utility model patent. The calcined coke is subjected to gravity and passes through the calcined coke cooler, i.e., the steam-water jacket, from top to bottom, and exchanges heat with the water in the steam-water jacket, and the water in the steam-water jacket produces steam or a steam-water mixture. Due to the forced pressurization by the circulating pump, the steam and water in the steam-water jacket flow smoothly, and the steam or steam-water mixture generated by the steam-water jacket is transported to the drum 101 through the ascending pipe 204 to continue the steam-water separation. If the thermal system for the waste heat recovery of the calcined coke is not equipped with a circulating pump and relies on natural circulation, the drum needs to be installed at a higher position, and the circulation power is weak. The utility model is equipped with a circulating pump, which can reduce the installation cost of the drum.

[0035] Furthermore, the steam collecting subunit 300 collects qualified steam generated by multiple steam drums set in the thermal system for recovering waste heat from calcined coke in the steam header 302 through the steam drum outlet steam pipeline 301, and then supplies it to subsequent steam users through the steam lead-out pipeline 303, which can be used for power generation, heating in winter or air conditioning in summer, or steam takeaway, etc., to produce better economic results.

[0036] Furthermore, the feedwater deoxygenation subunit 400 includes a deoxygenated steam pipeline 401, a deaerator 402, an external water supply pipeline 405, a drum feedwater pipeline 403 and a feedwater pump 404. The deoxygenation heat source of the feedwater deoxygenation subunit 400 comes from the steam in the steam header 302. The steam and external water supply enter the deaerator 402 for deoxygenation, and qualified water is delivered to the drum through the drum feedwater pipeline 403 and the feedwater pump 404. The water in the external water supply pipeline can be the return water of the steam user and the supplementary fresh desalted water. Its functions are to remove the dissolved oxygen in the water in the system and to provide water supply for the system. If the steam user cannot send the water back, the water supply of the system is mainly supplemented by the deaerator water supply. The external water supply needs to be deoxygenated, and the heat source for deoxygenation is the steam in the steam header.

[0037] Through the above specific implementation scheme, the calcined coke in the calciner can be safely cooled, and the steam-water production set 203 can be safely and stably operated. Compared with the traditional method, the production of steam using the heat of the calcined coke greatly improves the economic efficiency.

[0038] The above is only the preferred implementation of the utility model patent, but the utility model patent is not limited to the above specific implementation. For ordinary technicians in this field, several modifications and improvements can be made without departing from the creative concept, which all fall within the scope of protection of the utility model patent.

Claims

1. A thermal system suitable for recovering waste heat from calcined coke in a carbon calcining furnace, characterized in that: The thermal system includes a drum and its auxiliary facilities subunit, a steam-water jacket subunit, a steam collection subunit and a feedwater deoxygenation subunit; the steam-water jacket subunit is composed of a downcomer, a circulating pump, a steam-water jacket set and an ascending pipe; the steam collection subunit is composed of a drum outlet steam pipeline, a steam header and a steam outlet pipeline; the feedwater deoxygenation subunit is composed of a deoxygenated steam pipeline, a deaerator, an external water supply pipeline, a drum feedwater pipeline and a feedwater pump; wherein: The steam drum sequentially inputs the hot water separated from the steam drum to the steam-water production set through the downcomer and the circulating pump; the output end of the steam-water production set re-transmits the steam or the steam-water mixture to the steam drum through the upcomer; The steam drum inputs the steam separated by the steam drum to the steam header through the outlet steam pipeline, and the steam header outputs the treated steam to the subsequent utilization equipment through the steam lead-out pipeline on one side; the other side of its output end is connected to the deaerator through the deoxygenated steam pipeline; the output end of the deaerator sequentially delivers the deoxygenated hot water to the steam drum through the steam drum feed water pipeline and the feed water pump; The feed water deoxygenation subunit provides feed water to the steam drum through an external feed water pipeline.

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