CN1514200A

CN1514200A - Heat exchange system using maltiple L valve distribution

Info

Publication number: CN1514200A
Application number: CNA021566216A
Authority: CN
Inventors: 诚张; 张�诚
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-12-17
Filing date: 2002-12-17
Publication date: 2004-07-21
Anticipated expiration: 2022-12-17
Also published as: CN1285874C

Abstract

In the heat exchanging system, the used L valve is different from normal ones a valve outlet is a vertical straight-through pipe to separate gas and material here, gas is vented above to the air and dense material falls down from hole towards bottom. The channel structure which is enlarged gradually and integrated with centre inner cone and outer cone is applied by material falling hole, a storage bin with big enough volume is set above L valve to continuously supply material for it. High temperature material follen down from dropping bed is collectively sent into a J form valve and then to air heater of bubbling bed. The low temperature particles flowed out from bubbling bed is lifted to storage bin above material distributing device of L valve through another J valve.

Description

The cloud bed heat-exchange system that falls with a plurality of L valve clothes

The present invention is a kind of heat-exchange system that utilizes elevated temperature heat fume afterheat preheated air, particularly realizes the solid particle of uniform distribution and the cloud bed heat-exchange system that falls of high-temperature flue gas countercurrent flow with a plurality of L valves.

Utilization is the important means of saving energy in kiln with air preheat with the high-temperature flue gas heat that reclaims various kilns.Tubular type commonly used and rotary regenerative air preheater all transmit heat by metal, and the temperature of institute's preheated air is limited by the heat-resisting degree of metal.Carbon steel preheater hot blast temperature is no more than 400 ℃, and is too expensive with heating resisting metal.For improve hot blast temperature commonly used be the hot-blast stove of constructing with refractory material, it realizes heat exchange by intermittently switching the ventilation direction, its volume is very big, and is a lot of with material, and hot blast temperature is cyclic fluctuation.Making solid thermal carriers with particle has two kinds of forms with the heat exchange of fluid bed form in fume side, and a kind of is downflow type, and promptly particle is fed by temperature end, is heated with flow of flue gas, after separated device separates, changes another bubbling bed and air over to and does the cross-current heat exchange.The mean temperature difference of following current heat exchange is little, and the particle outlet temperature is low, so hot blast temperature is low; Another kind is reverse-flow, be that particle falls from top to bottom with the cloud form that falls, air-flow from bottom to top, its relative velocity is the particle limit, sinking speed, the numerical value height, heat transfer coefficient is also just high, and particle is warm eventually in the fume high-temperature district, and temperature is high eventually, mean temperature difference is big, is that a kind of people wish the heat transfer type realized very much.The cloud bed heat-exchange system that falls is strong to dusty gas adaptability, yet the difficult point of gas-solid countercurrent flow is how to make uniform particles to be distributed in the air-flow.Practice finds, particle is in case poly-group only just is difficult to it is disperseed by air-flow, and gas more becomes to flowing to the sparse zone of air, and therefore, the target of the good contact of gas-solid is difficult to realize.The present invention notices These characteristics, adopts a series of measures pointedly.

Heat-exchange system of the present invention at first comprises the cloud bed that falls, and is generally cylindrical tube (1), and high-temperature flue gas (2) is entered by the bottom, flows from bottom to top.Solid particle is fallen by bed top (4).It is considered herein that the uniformity that initially feeds solid particle and adjacent with it exhanst gas outlet structure are most important.General structure distributing device is difficult to continuous firing at high temperature, in case find that inequality also is difficult to regulate.L valve group distributing device (6) the control cloth that the present invention advises using a plurality of L valves (5) of subregion to constitute.Look cloud bed diameter and be divided into 3-8 district, in each district 3-20 cloth L valve arranged at circumferencial direction.So-called L valve is made up of a vertical material blanking tube and a horizontal channel, and control horizontal section length L is about three times of diameter D, and an air injection pipe is arranged in the material blanking tube bottom.The mass flow of L valve is controlled by gas injection rate, regulate the gas injection rate (7) in each district and just can regulate the blanking amount, be engaged near the gas outlet (8) of discharging point with it and should adopt radial giving vent to anger of full week, establishing thermometer (19) in corresponding gas outlet, each district should increase feeding coal to the higher district of air outlet temperature, and the district that temperature is on the low side should reduce feeding coal makes it balanced as far as possible.Different with general L valve, it is that a straight vertical is threaded a pipe that the present invention requires L valve outlet port place, and gas so far separates with material, and gas is got rid of by the sky, and close dense material is fallen by downward hole.(figure two) 1. can not interrupt for the supplied materials that guarantees the L valve, and should there be the enough big feed bin of a capacity (10) top of L valve.The high-temperature material that is fallen by the cloud bed that falls is concentrated to send into a J type valve (11), enter bubbling bed air heater (12) by J type valve material, cryogenic particles by the bubbling bed flows out enters material lifting device (14) by another J valve (13), the feed bin of the referred L valve of material distributing device top.Certainly high-temperature material also can be raised earlier, separates the back and enters bubbling bed air heater by another J valve, and the cryogenic particles that is flowed out by the bubbling bed directly enters high hopper.Nature, the empty tower gas velocity of bubbling bed will be lower than the empty tower gas velocity of cloud bed, and generally calculating the former by mark attitude aerodromometer is the latter's 30-60%, and the terminal falling velocity of particle is between two superficial linear velocity in a columns.

30000Nm is for example arranged ³The flue gas that/h is 1100 ℃ is used to heat already that tubular preheater is preheating to 350 ℃ same amount air, and selecting particle diameter is that particles such as the bauxite of 1-1.3mm or Coaseries kaolin are made heat carrier, and the cloud bed net heat that falls exchange highly is 12m, and diameter is 3.5m.Cloth adopts 6 subregions, 61 L valve cloth tubes.The exhanst gas outlet temperature is 700 ℃, and particle is 1000 ℃ from bed tempertaure, and through promoting and bubbling bed air heater, particle temperature has been lowered to 600 ℃, and air is heated to 750 ℃.The recycle stock amount is 50t/h.1. material-dropping hole adopts and forms flaring channel design (figure three) by inner cone and outer cone

Description of drawings: figure one is a structural representation of the present invention; Figure two is cutaway views of L valve of the present invention; Figure three is cutaway views of blanking port of the present invention.

Claims

1. when adopting the heat exchange of cloud bed, adopt the L valve group distributing device control cloth that constitutes by a plurality of L valves.

2. according to claim 1, L valve group along the circumferential direction is divided into 3-8 district, in each district 3-20 cloth L valve is arranged.

3. according to claim 1, the gas vent of the cloud bed heat exchanger that falls adopts radial giving vent to anger of full week, and corresponding each cloth district is provided with an Outlet Gas Temperature measuring point, according to the aeration quantity in the corresponding district of outlet air temperature adjusting, and then regulates feeding coal.

4. according to claim 1, this L valve Horizontal Exit place is a straight-through up and down vertical pipe, and last hole is used to give vent to anger, and following hole is used for blanking, and material-dropping hole adopts the flaring channel design of being made up of center inner cone and outer cone.