阅读说明：本技术 食盐干燥尾气余热回收系统 (Salt drying tail gas waste heat recovery system ) 是由 宋继田 苏杭 蔡开街 周山林 石冬琦 毕晓旭 向彬彬 吴怡然 于 2019-09-20 设计创作，主要内容包括：本发明涉及一种食盐干燥尾气余热回收系统,热风炉连接至流化床干燥器的流化气体进口；旋风分离器的出气口通过第一进气管连接至第一水吸附塔；流化床干燥器的气体出口连接至引风机,第一水吸附塔顶端的出气口连接至空气预热器；物料预热单元包括料浆输送管、料浆泵及热交换喷淋塔,料浆输送管上设置有料浆泵,料浆输送管经过热交换喷淋塔内部后连接流化床干燥器的物料进口。本发明设计科学合理,能够去除食盐干燥尾气对换热管壁的腐蚀,降低尾气的湿度及粉尘,防止换热管的结垢,提高传热效率；同时能够对尾气热量进行回收利用,提高能源利用率。(The invention relates to a salt drying tail gas waste heat recovery system, wherein a hot blast stove is connected to a fluidized gas inlet of a fluidized bed dryer; an air outlet of the cyclone separator is connected to the first water adsorption tower through a first air inlet pipe; a gas outlet of the fluidized bed dryer is connected to an induced draft fan, and a gas outlet at the top end of the first water adsorption tower is connected to an air preheater; the material preheating unit comprises a slurry conveying pipe, a slurry pump and a heat exchange spray tower, the slurry pump is arranged on the slurry conveying pipe, and the slurry conveying pipe is connected with a material inlet of the fluidized bed dryer after passing through the inside of the heat exchange spray tower. The invention has scientific and reasonable design, can remove the corrosion of salt dry tail gas on the heat exchange tube wall, reduce the humidity and dust of the tail gas, prevent the scaling of the heat exchange tube and improve the heat transfer efficiency; meanwhile, the heat of the tail gas can be recycled, and the energy utilization rate is improved.)

1. The utility model provides a salt drying tail gas waste heat recovery system which characterized in that: the system comprises a fluidized gas preheating unit, a fluidized bed dryer, a tail gas treatment unit and a material preheating unit, wherein the fluidized gas preheating unit comprises a high-pressure blower, an air preheater and a hot blast stove which are sequentially connected in sequence, and the hot blast stove is connected to a fluidized gas inlet of the fluidized bed dryer; the tail gas treatment unit comprises an induced draft fan, a cyclone separator and a first water absorption tower which are sequentially connected, wherein a gas outlet of the cyclone separator is connected to the first water absorption tower through a first gas inlet pipe; a gas outlet of the fluidized bed dryer is connected to the induced draft fan, and a gas outlet at the top end of the first water adsorption tower is connected to the air preheater through a first gas outlet pipe; the material preheating unit comprises a slurry conveying pipe, a slurry pump and a heat exchange spray tower, wherein the slurry pump is arranged on the slurry conveying pipe, the slurry conveying pipe passes through the heat exchange spray tower and is connected with the rear part inside the fluidized bed dryer, and a water spray head is arranged in the heat exchange spray tower.

2. The salt drying tail gas waste heat recovery system according to claim 1, characterized in that: still include the second water absorption tower, the second water absorption tower with the parallelly connected setting of first water absorption tower, the gas outlet on second water absorption tower top is connected to through the second outlet duct air heater, cyclone's gas outlet is through second intake-tube connection to the second water absorption tower, the top of first, second water absorption tower is connected to through first gas blow pipe, second gas blow pipe respectively the hot-blast furnace, the bottom of first, second water absorption tower is connected to through first blast pipe, second blast pipe respectively the heat exchange spray column, be provided with the tail gas vent on the heat exchange spray column, all be provided with the valve in first gas blow pipe, second gas blow pipe, first outlet duct, second outlet duct, first blast pipe, second blast pipe, first intake pipe and the second intake pipe.

3. The salt drying tail gas waste heat recovery system according to claim 1, characterized in that: and air filters are arranged on the first air blowing pipe and the second air blowing pipe between the first water adsorption tower and the hot blast stove and between the second water adsorption tower and the hot blast stove.

4. The salt drying tail gas waste heat recovery system according to claim 1, characterized in that: and the parts of the slurry conveying pipes extending into the heat exchange spray tower are spirally arranged.

Technical Field

The invention belongs to the technical field of chemical unit operation, relates to salt drying, and particularly relates to a salt drying tail gas waste heat recovery system.

Background

In the existing technology for recovering the waste heat of tail gas in salt industry, normal temperature air enters a hot blast stove for heating and warming after being preheated by primary tail gas, heated high-temperature dry air enters a fluidized bed dryer for carrying away moisture in the fluidized bed dryer and carrying away the moisture in the fluidized bed dryer and the moisture-containing salt, the dehydrated salt is cooled and then discharged, and the dried high-temperature tail gas is separated from dust by a cyclone dust collector and then is discharged after primary heat exchange with the normal temperature air in an air preheater. However, the tail gas humidity of hot-air behind the convection drying among the above-mentioned technology is great, contains more vapor, mixes a large amount of sodium chloride and sodium sulfate, and it has the drop of water to condense out to reach its dew point after through the heat transfer cooling with normal atmospheric temperature air in air heater, forms the one deck and contains the liquid layer of sodium chloride, sodium sulfate, if the not high liquid layer mixing caking that still can with the condensation of dust separation efficiency, not only hinders its heat transfer, contain the salt liquid layer moreover and adhere to on the pipe wall gradually and corrode the heat exchange tube for a long time.

Through a search for a patent publication, no patent publication that is the same as the present patent application is found.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a salt drying tail gas waste heat recovery system, which can remove the corrosion of salt drying tail gas on the heat exchange pipe wall, reduce the humidity and dust of the tail gas, prevent the scaling of a heat exchange pipe and improve the heat transfer efficiency; meanwhile, the heat of the tail gas can be recycled, and the energy utilization rate is improved.

The technical problem to be solved by the invention is realized by the following technical scheme:

the utility model provides a salt drying tail gas waste heat recovery system which characterized in that: the system comprises a fluidized gas preheating unit, a fluidized bed dryer, a tail gas treatment unit and a material preheating unit, wherein the fluidized gas preheating unit comprises a high-pressure blower, an air preheater and a hot blast stove which are sequentially connected in sequence, and the hot blast stove is connected to a fluidized gas inlet of the fluidized bed dryer; the tail gas treatment unit comprises an induced draft fan, a cyclone separator and a first water absorption tower which are sequentially connected, wherein a gas outlet of the cyclone separator is connected to the first water absorption tower through a first gas inlet pipe; a gas outlet of the fluidized bed dryer is connected to the induced draft fan, and a gas outlet at the top end of the first water adsorption tower is connected to the air preheater through a first gas outlet pipe; the material preheating unit comprises a slurry conveying pipe, a slurry pump and a heat exchange spray tower, wherein the slurry pump is arranged on the slurry conveying pipe, the slurry conveying pipe passes through the heat exchange spray tower and is connected with the rear part inside the fluidized bed dryer, and a water spray head is arranged in the heat exchange spray tower.

And, still include the second water absorption tower, the second water absorption tower with first water absorption tower parallel arrangement, the gas outlet on second water absorption tower top is connected to through the second outlet duct air heater, cyclone's gas outlet is connected to through the second intake-tube second water absorption tower, the top of first, second water absorption tower is connected to through first gas blow pipe, second gas blow pipe respectively the hot-blast furnace, the bottom of first, second water absorption tower is connected to through first blast pipe, second blast pipe respectively the heat exchange spray column, be provided with the tail gas vent on the heat exchange spray column, all be provided with the valve on first gas blow pipe, second gas blow pipe, first outlet duct, second outlet duct, first blast pipe, second blast pipe, first intake pipe and the second intake pipe.

And air filters are arranged on the first air blowing pipe and the second air blowing pipe between the first water adsorption tower and the hot blast stove and between the second water adsorption tower and the hot blast stove.

And the part of the slurry conveying pipe extending into the heat exchange spray tower is spirally arranged.

The invention has the advantages and beneficial effects that:

1. the salt drying tail gas waste heat recovery system comprises a tail gas treatment unit and a material preheating unit, wherein the tail gas treatment unit can remove moisture and dust in tail gas, and maintain the temperature of the tail gas while efficiently removing dust and moisture, so that the heat exchange of the tail gas cannot generate condensed water to corrode a pipe wall, and the heat exchange efficiency is ensured; the heat exchange spray tower is used for recovering the heat of the wet salt so as to improve the feeding temperature of the wet salt and reduce the consumption of the dry gas.

2. The salt drying tail gas waste heat recovery system also comprises a second water absorption tower, high-temperature flue gas generated by the hot blast stove is used as regeneration gas of water absorbents of the first water absorption tower and the second water absorption tower, after the first water absorption tower is saturated, the flue gas passing through the air filter is used as the regeneration gas of the water absorbent in the second water absorption tower through a switching valve, at the moment, the first water absorption tower is in a regeneration process, the second water absorption tower is in a tail gas absorption process until the first water absorption tower is saturated, the flue gas is alternately recycled, the working continuity of the system is ensured, and the utilization rate of the heat of the flue gas is improved.

3. According to the salt drying tail gas waste heat recovery system, the air filters are arranged on the first air blowing pipe and the second air blowing pipe between the first water adsorption tower and the hot blast stove and between the second water adsorption tower and the hot blast stove, so that gas in the hot blast stove can be filtered, the purity of the gas entering the adsorption towers is ensured, and the pipe wall scaling caused by dust in the recycling process is prevented.

4. According to the salt drying tail gas waste heat recovery system, the parts of the slurry conveying pipes extending into the heat exchange spray tower are arranged in a spiral mode, so that sufficient heat exchange of slurry in the heat exchange spray tower can be guaranteed, the feeding temperature of salt is increased, and the consumption of drying gas in the fluidized bed dryer is reduced.

5. The invention has scientific and reasonable design, can remove the corrosion of salt dry tail gas on the heat exchange tube wall, reduce the humidity and dust of the tail gas, prevent the scaling of the heat exchange tube and improve the heat transfer efficiency; meanwhile, the heat of the tail gas can be recycled, and the energy utilization rate is improved.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Description of the reference numerals

The system comprises a 1-high-pressure blower, a 2-air preheater, a 3-hot blast stove, a 4-fluidized bed dryer, a 5-air filter, a 6-induced draft fan, a 7-cyclone dust collector, an 8-circulating water adsorption tower, a 9-heat exchange spray tower, a 10-water spray head, an 11-slurry pump, a 12-slurry conveying pipe, a 13-tail gas discharge port, a 14-overflow pipe orifice, a 15-first water adsorption tower and a 16-second water adsorption tower.

Detailed Description

The present invention is further illustrated by the following specific examples, which are intended to be illustrative, not limiting and are not intended to limit the scope of the invention.

A salt drying tail gas waste heat recovery system is characterized in that: comprises a fluidized gas preheating unit, a fluidized bed dryer 4, a tail gas treatment unit and a material preheating unit.

The fluidized gas preheating unit comprises a high-pressure blower 1, an air preheater 2 and a hot blast stove 3 which are sequentially connected in sequence, the hot blast stove is connected to a fluidized gas inlet of the fluidized bed dryer, and preheated and heated air is used as fluidized drying gas of the fluidized bed dryer.

The material preheating unit comprises a slurry conveying pipe 12, a slurry pump 11 and a heat exchange spray tower 9, the slurry pump is arranged on the slurry conveying pipe, the slurry conveying pipe is connected with a material inlet of the fluidized bed dryer after passing through the inside of the heat exchange spray tower, a water spray head 10 and an overflow pipe opening 14 are arranged in the heat exchange spray tower, salt slurry preheated by the heat exchange spray tower enters the fluidized bed dryer to be dried, the initial temperature of salt is increased, and the using amount of fluidized drying gas is reduced.

The tail gas treatment unit comprises a draught fan 6, a cyclone separator 7 and a first water absorption tower 15 which are sequentially connected, and an air outlet of the cyclone separator is connected to the first water absorption tower through a first air inlet pipe; a gas outlet of the fluidized bed dryer is connected to an induced draft fan, a gas outlet at the top end of the first water adsorption tower is connected to an air preheater through a first gas outlet pipe, tail gas of the fluidized bed dryer is dedusted through a cyclone separator to remove 95% of dust, and is dehumidified and dried through the first water adsorption tower, pure dry gas with heat is sent into the air preheater, the preheating temperature of the fluidized gas is increased, and the heat is fully utilized; and the tail gas is dehumidified and dried in time, so that the heat exchange of the tail gas is ensured, condensate water cannot be generated to corrode the pipe wall, and the heat exchange efficiency is ensured.

The device also comprises a second water adsorption tower 16, the second water adsorption tower and the first water adsorption tower are arranged in parallel to form a circulating water adsorption tower 8, an air outlet at the top end of the second water adsorption tower is connected to an air preheater through a second air outlet pipe, an air outlet of a cyclone separator is connected to the second water adsorption tower through a second air inlet pipe, the top ends of the first water adsorption tower and the second water adsorption tower are respectively connected to a hot blast stove through a first air blowing pipe and a second air blowing pipe, the bottom ends of the first water adsorption tower and the second water adsorption tower are respectively connected to a heat exchange spray tower through a first exhaust pipe and a second exhaust pipe, a tail gas exhaust port 13 is arranged on the heat exchange spray tower, the first air blowing pipe, the second air blowing pipe, the first air outlet pipe, the second air outlet pipe, the first exhaust pipe, the second exhaust pipe, the first air inlet pipe and the second air inlet pipe are respectively provided with valves, high-temperature flue gas, after the first water absorption tower reaches saturation, the flue gas passing through the air filter is used as the regeneration gas of the water absorbent in the second water absorption tower through the switching valve, at the moment, the first water absorption tower is in the regeneration process, the second water absorption tower is in the tail gas absorption process until saturation, and the flue gas is alternately recycled, so that the working continuity of the system is ensured, and the utilization rate of the heat of the flue gas is improved.

Air cleaner 5 is provided with on first gas blow pipe and the second gas blow pipe between first water adsorption tower and second water adsorption tower and the hot-blast furnace, can filter the gas of hot-blast furnace, guarantees to get into the pure and clean degree of gas in the adsorption tower, prevents that recycle in-process dust from causing the pipe wall scale deposit.

The part that the ground paste conveyer pipe stretched into the heat exchange spray tower is spiral and arranges, can guarantee the abundant heat transfer of ground paste in the heat exchange spray tower to promote the feed temperature of salt, reduce the dry gas quantity in the fluidized bed dryer.

Although the present invention has been disclosed in connection with the embodiments and drawings, it will be understood by those skilled in the art that: various substitutions, changes and modifications are possible without departing from the spirit and scope of the invention and the appended claims, and therefore the scope of the invention is not limited to the disclosure of the embodiments and the accompanying drawings.