CN201159600Y - Roasting furnace waste heat recovery device - Google Patents

Abstract

Disclosed is a roasting oven waste heat recovery device, comprising a heat pipe evaporator and a steam separator. A clapboard divides the heat pipe evaporator into a stock gas side and a vapour side; the stock gas side is arranged inside a descending stock gas pipeline and the vapour side is connected with the steam separator. The utility model makes use of the characteristics and advantages of thermotube technique to solve the problem in waste heat recovery in the environment with high-temperature, high-dust and high-dew-point corrosive stock gas from the dust removal process to the purification process in the production of sulphuric acid; the waste heat recovery device can operates safely and reliably in a long time; the waste heat recovery device recycles the waste heat in the stock and reduces the water consumption of the following processes; the low-pressure saturated vapour can be supplied to the production of other workshop sections or be used in daily life and can create considerable economic benefits and social benefits for enterprises.

Description

Roasting furnace waste heat recovery device

technical field

The utility model relates to waste heat recovery equipment in pyrite acid production, which is mainly used in the production process of pyrite acid production, in particular to a roasting furnace waste heat recovery device.

Background technique

At present, in the production of sulfuric acid from pyrite ore, pyrite ore is roasted in a fluidized roasting furnace, and the furnace gas containing a large amount of SO ₂ and a small amount of SO ₃ is first passed through a medium-temperature and medium-pressure waste heat boiler for waste heat recovery. After passing through the cyclone dust removal device, and then through the electric dust removal device (some manufacturers have no electric dust removal device), the temperature of the furnace gas is 320 ℃ ~ 380 ℃, enters the purification section, and then cools the temperature of the furnace gas to 60 ~ 70 ℃ through cooling tower water cooling before entering the subsequent However, the water cooling of the furnace gas not only makes the waste heat of the furnace gas not be used reasonably, but also increases the temperature of the on-site working environment to form thermal pollution, and also wastes a lot of water resources to reduce the temperature of the furnace gas. In addition, the furnace gas contains a large amount of SO ₂ and a small amount of SO ₃ and H ₂ O, and the dew point temperature of the furnace gas is generally around 230°C. If the temperature is too low, dew point corrosion will occur, and once it leaks, it will not be repaired, which will affect the overall operation of the system. At the same time, the furnace gas also contains a large amount of ash, and the problem of ash accumulation in the heat exchanger is also a factor affecting the continuous operation of the system. Therefore, the furnace gas after dedusting has not been properly recovered and utilized for waste heat.

Contents of the invention

The problem to be solved by the utility model is: in the pyrite acid production, the residual heat of the furnace gas from the dust removal to the purification section has not been reasonably recovered and utilized; due to the production environment of high temperature, high dust, and high dew point corrosion Tube and tube heat exchangers cannot meet the requirements for use.

The technical scheme of the utility model is: the waste heat recovery device of the roasting furnace is arranged on the furnace gas pipeline, and includes a heat pipe evaporator and a steam-water separator. The heat pipe evaporator is divided into a furnace gas side and a water vapor side. The two sides of the water vapor side are provided with a steam outlet and a water inlet, which are respectively connected with the steam inlet and water outlet of the steam-water separator, and the water inlet is close to the furnace gas side.

The heat pipe element and the collecting pipe on the water vapor side of the heat pipe evaporator of the utility model are both of water jacket structure. After the heat pipe furnace gas side absorbs the heat of the furnace gas, it is transferred to the water vapor side. Steam separator, converted to saturated steam. After the heat pipe evaporator is separated by the partition, one side passes the furnace gas, and the other side passes the water vapor. The two heat exchange media do not directly contact, but transfer heat through the heat pipe element. Because of the partition, even if the heat pipe on the furnace gas side corrodes and leaks , It will not cause water vapor and furnace gas to communicate, and the water vapor side can still operate normally, and the system will not be shut down due to this equipment.

Because an important factor affecting the heat transfer efficiency of the heat pipe is its installation method, the pipeline at the heat dissipation end must be installed higher than the heat absorption end to be effective. The furnace gas side of the heat pipe evaporator of the utility model is equivalent to the heat absorption end. The water vapor side is equivalent to the heat dissipation end, so the position of the water vapor side is higher than that of the furnace gas side, and the position of the outlet end of the water vapor side is higher than that of the water inlet end.

Furnace gas contains a certain amount of ash during production. Considering the problem of ash accumulation, as a further improvement, the furnace gas side of the heat pipe is arranged nearly horizontally, forming an angle of 0-60° with the horizontal plane, and the fins welded outside the pipe are arranged vertically to the heat pipe. In this way, it is not easy to accumulate dust, and a large amount of ash contained in the furnace gas will fall down by itself due to the action of gravity, which has the effect of self-cleaning dust.

The utility model makes full use of many advantages of the heat pipe itself, such as high heat transfer efficiency, small flow resistance loss of hot fluid, mutual non-leakage of hot fluid and cold fluid, compact structure, replaceable components, etc. The vaporization is completed outside the furnace gas pipeline, and the temperature of the furnace gas after waste heat recovery can be reduced to 170-250°C; the temperature of the heat pipe wall is controlled by controlling the heat flux density of the hot and cold fluid side of the heat pipe, and the temperature of the heat pipe wall is kept as high as possible. It is always higher than 220°C, so as to avoid the dew point temperature and solve the problem of dew point deposition and corrosion; the heat pipe evaporator is connected to the steam-water separator through a conduit, and the pipeline layout is flexible; the furnace gas side and the water vapor side are separated by a partition, and any leakage on either side It will not affect the operation of the other side, ensuring the continuous, safe and reliable operation of the whole sulfuric acid system; The water consumption of the workshop section, and the low-pressure saturated steam produced can be supplied to other workshop sections for production and domestic use, and can create considerable economic and social benefits for the enterprise.

Description of drawings

Fig. 1 is a schematic diagram of the utility model.

Fig. 2 is a schematic diagram of the heat pipe evaporator of the present invention divided into a furnace gas side and a water vapor side by a partition.

Detailed ways

The utility model adopts heat pipes as heat exchanging elements, and the heat pipe elements are connected in parallel or in series through collector pipes to form a heat pipe evaporator, and a partition plate separates the heat pipe evaporator into a furnace gas side and a water vapor side, and the furnace gas side absorbs the heat transfer of the furnace gas To the water vapor side, the water vapor side releases the heat to the water vapor. The furnace gas and water vapor are not in direct contact with the two heat exchange media, and the heat is transferred through the heat pipe element, so that while reducing the temperature of the furnace gas, a large amount of saturated steam is generated for use in other sections. Realize waste heat recovery of furnace gas. The many advantages of the heat pipe itself and the equipment can fundamentally avoid the contact between the sulfur-containing furnace gas and the water vapor, and at the same time, the equipment has a self-cleaning effect through the structural design. Moreover, even if the heat pipe on the furnace gas side corrodes and leaks, water vapor and furnace gas will not communicate with each other.

The utility model will be further explained below in conjunction with accompanying drawings 1-2: the furnace gas coming out of the fluidized roasting furnace is arranged at a high position, and after passing through the medium-temperature and medium-pressure waste heat boiler-cyclone dust removal-electric dust removal, it enters the purification section along the descending furnace gas pipeline. The descending furnace gas pipeline 8 of the utility model is arranged between the outlet of the deduster and the purification section. The heat pipe evaporator 5 is composed of multiple heat pipes 6 connected in parallel or in series through the collector pipe 4. A partition 7 connects the heat pipe evaporator 5 is divided into a furnace gas side 9 and a water vapor side 10, the furnace gas side 9 is set in the descending furnace gas pipeline 8, and the two sides of the water vapor side 10 are provided with a steam outlet 2 and a water inlet 3, which are respectively connected to the steam-water separator 1 through conduits The steam inlet is connected to the water outlet, wherein the water inlet 3 is close to the furnace gas side 9, the steam outlet 2 is higher than the water inlet 3, and the heat pipe element and the header 4 on the water vapor side 9 are all water jacket structures. As shown in Figure 1, the furnace gas passes through the furnace gas side 9 of the heat pipe evaporator 5 from top to bottom through the furnace gas pipeline 8, the heat pipe on the furnace gas side absorbs heat, and transfers the heat to the steam-water side 10 through the working medium in the tube to release heat, and the steam-water is separated The nearly saturated water in the device 1 enters the jacket of the water vapor side heat pipe and the header 4 from the water inlet end 3 along the conduit, the water absorbs the heat released by the heat pipe 6, and the heated water reaches a certain temperature under a certain pressure It turns into a steam-water mixture. Due to the density difference of the steam side 10, the steam-water mixture enters the steam-water separator 1 from the steam outlet 2 along the conduit to realize the separation of steam and water, and generates saturated steam with a certain pressure for use in other production sections. The generated nearly saturated water is recycled Enter the water vapor side 10 from the water inlet end 3 along the conduit. The heat pipe evaporator 5 adopts a horizontal structure, which forms a certain angle with the horizontal plane. The fins 11 welded outside the tube are arranged vertically to the heat pipe, which is not easy to accumulate dust. A large amount of ash contained in the furnace gas will fall down by itself due to the action of gravity, which has a self-cleaning effect. As shown in Figure 2, since the heat pipe 6 is divided into two parts by the partition plate 7, the furnace gas side 9 and the water vapor side 10 are completely isolated, and the hot and cold fluids are separated from the two sides, and the leakage of any side will not affect the other side. operation to ensure the continuous, safe and reliable operation of the entire sulfuric acid system.

Claims (5)

1, roaster waste-heat recovery device, be arranged on the furnace gas pipeline, it is characterized in that comprising heat pipe evaporator and steam-water separator, heat pipe evaporator is formed by header parallel connection or tandem compound by heat-pipe elements, one dividing plate is divided into furnace gas side and steam side with heat pipe evaporator, the both sides of steam side are provided with steam output end and water inlet end, link to each other with the water side with the admission end of steam-water separator respectively, and wherein water inlet end is near the furnace gas side.

2, roaster waste-heat recovery device according to claim 1 is characterized in that the heat-pipe elements of steam side and header are the water leg structure.

3, roaster waste-heat recovery device according to claim 1 and 2 is characterized in that the furnace gas side of heat pipe evaporator becomes 0-60 ° of angle with horizontal plane.

4, roaster waste-heat recovery device according to claim 1 and 2 is characterized in that the steam outlet pipe of steam side links to each other with the water side with the admission end of steam-water separator respectively by conduit with water inlet pipe.

5, roaster waste-heat recovery device according to claim 3 is characterized in that the steam outlet pipe of steam side links to each other with the water side with the admission end of steam-water separator respectively by conduit with water inlet pipe.

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