A kind of coal low-temperature carbonization system and method
Technical field
The present invention relates to retorting technique, particularly relate to the low temperature distillation technology of a kind of coal.
Background technology
At present, the dry distillation of coal refers to that coal heats under isolation air conditions, decomposes generation coke (semicoke),
Coal tar, coal gas and the process of pyrolysis water.The low temperature distillation of coal refers to use relatively low heating final temperature to make coal
There is pyrolytic reaction, it is considered that low temperature distillation final temperature is 500-700 DEG C.
The low temperature distillation of coal is divided into internal heat type and external-heat by mode of heating.Traditional gas retort mostly is exterior-heat
Formula, the externally heated retort oven thermal efficiency is low, and material is heated uneven, and volatility product second pyrolysis is the most serious.
Internally heated retort oven directly contacts with coal by heat carrier and heat is directly transmitted to coal charge, makes coal be pyrolyzed
Reaction, has the features such as heating fast, efficiency height, homogeneous heating.Outside though internal heat type low-temperature dry distillation overcomes
The deficiency of hot type and shortcoming, but internal heat type dry distilling mostly is high-temperature flue gas makees heat carrier, with the cigarette after coal heat exchange
Gas is blended in coal gas with pyrolysis of coal product together extraction gas retort, reduces calorific value and the quality of coal gas.
Have employed dry distilling purified gas in its Patent CN101885973A as heat carrier, purified gas is at gas retort
Outside after recuperator is heated to 450-900 DEG C, it is passed through gas retort and directly contacts with coal and be pyrolyzed
Reaction, this technique coal gas purity is suitable with external-heat technique, and calorific value is high, and coal charge is heated quick, uniform.
But this process high-temperature purified gas is to be obtained by outside recuperator heating, carries as heat with high-temperature flue gas
Body is compared, and system thermal efficiency is low.
The moving-bed retorting furnace (CN101712878B) that a kind of radial canal and circulating current comprehensively heat is situated between
The radial canal mode that uses the gas retort that continued heats and the pyrolysis of circulating current heat transfer type, and fuel flue gas walks radiation
In pipe, radial canal radiation heating coal seam, it is achieved that flue gas and the isolation of pyrolysis coal gas, to gas from burner hearth
One end removal, from the other end move into, conveying to gas be containing pyrolysis water, Jiao oil and gas mix
Closing medium, the dynamic equipment to gas that carries is blower fan.This technique uses aqueous, the raw gas of tar, gas
As circulative convection gas, in circulating line and device memory at dust, tar condensing equivalent risk, to circulation
Dynamic equipment requirements is harsh, and the waste heat of high temperature semi-coke does not make full use of simultaneously.
Summary of the invention
Present invention aim to address subproblem present in existing coal low temperature distillation technology, it is provided that a kind of
Coal low-temperature carbonization system and method.
It is an object of the invention to be achieved through the following technical solutions:
A kind of coal low-temperature carbonization system, including revolving bed dry distilling unit, raw coke oven gas washing, tar trapping list
Unit, coal gas convection unit and coal gas dry coke quenching unit, described revolving bed dry distilling unit is sequentially connected with raw coke oven gas
Washing, tar capture unit, coal gas convection unit and coal gas dry coke quenching unit, described revolving bed dry distilling list
The coke outlet of unit is connected with the Jiao Kou that enters of coal gas dry coke quenching unit, and the gas of described revolving bed dry distilling unit enters
Mouth is connected with the gas exit of coal gas dry coke quenching unit, and described coal gas dry coke quenching unit uses cylinder dry coke quenching
Device.
Preferably, described revolving bed dry distilling unit is provided with isolation gas radiation pipe, drapery panel and gas distribution dress
Put.
Preferably, described isolation gas radiation pipe is arranged on the top of the bed of material, bottom or top and the bottom.
Preferably, the quantity of described cylinder dry coke quenching auxiliary is 1-5 level, is provided with heat exchange in described cylinder
Component.
Preferably, described coal gas convection unit includes purified gas device and convection flow fan.
A kind of method utilizing described system that coal is carried out low temperature distillation, it is characterised in that include following
Step:
(1) broken feed coal enters revolving bed dry distilling unit and carries out dry distilling, semi-coke by furnace side discharging,
High temperature oil, air and heat Xie Shui are by furnace roof extraction;
(2) high temperature oil of extraction, air and heat Xie Shui are carried out through raw coke oven gas washing, tar capture unit
Gas purification and tar are collected, and collect the tar obtained and purified gas for oil, gas product;Purified gas passes through
The convection flow fan of coal gas convection unit enters coal gas dry coke quenching unit, as the cooling medium of semi-coke;
(3) coal gas of high temperature after dry coke quenching enters revolving bed dry distilling unit, by distribution device from lower to
On uniformly across dry distilling coal seam, coal is complete under the effect that coal gas of high temperature heat convection and radial canal radiate heating
Become retort process;
(4) semi-coke after dry distilling obtains product semi-coke after coal gas dry coke quenching unit cools down.
Preferably, the fire box temperature in described step 1 is 500-700 DEG C.
Preferably, in described step 3 coal gas of high temperature after dry coke quenching from being positioned at the revolving bed gas retort bed of material
The burner hearth in face enters revolving bed dry distilling unit.
Preferably, by drum rotation speed and the gas flow rate of regulation cylinder dry coke quenching auxiliary in described step 4
Control the time of contact of coal gas and semi-coke, it is ensured that semi-coke temperature≤85 DEG C after quenching.
Beneficial effects of the present invention:
(1) dry distilling unit uses isolation gas radiation pipe heating revolving bed gas retort device, from the bed of material
The high temperature circulation coal gas that face burner hearth introduces, bottom-up simultaneously can be quickly dry distilling through coal seam heat convection
Oil gas product carries gas retort outside, shortens oil gas residing time in furnace, reduces second pyrolysis reaction, improves
The productivity of tar, tar yield can reach more than the 90% of lattice gold test;
(2) compare with traditional isolation gas radiation pipe heating revolving bed gas retort device, this dry distilling side
Method have employed to completely cut off the radiation of gas radiation pipe and is heated to be master, changes through coal seam convection current with high temperature circulation coal gas
Heat is auxiliary, it is achieved that the bed of material is heated Quick uniform, and retorting time is 30-80min, improves separate unit dry distilling
Stove treating capacity, production capacity improves up to 33%;
(3) one or more levels close phase cylinder dry coke quenching auxiliary is used to realize purified gas direct heat transfer, cylinder
There is component inside, controls heat-exchange time by regulating rotation speed of drum and gas flow rate, and semi-coke Exposure degree is imitated
Rate is high, up to more than 85%;
(4) isolation gas radiation pipe heating revolving bed dry distilling, circulation purified gas dry coke quenching, high temperature are used
Circulating gas heat convection technique couples, and directly reclaims dry distilling solid product semi-coke sensible heat and is used for as the dry distillation of coal
Heat supply, reduces distillation system energy consumption, average dry distilling ton coal energy-conservation more than 15%;
(5) use purified gas circulative convection heat exchange, retorted product gas do not have foreign matter gas dilution,
Dry distillation gas calorific value is high, calorific value of gas > 5000kcal/Nm3;
(6) using circulation purified gas is that pyrolysis of coal is to gas, the type selecting difficulty of reduction wind motor device;
(7) the purified gas quenching heat exchange after cooling is used, high temperature purified gas convection current pyrolysis raw coal after heat exchange,
The high temperature semi-coke sensible heat for pyrolysis unit that can reclaim accounts for total combustion gas energy consumption more than 9%.
Accompanying drawing explanation
Fig. 1 is a kind of coal low-temperature carbonization system flow chart;
1, revolving bed dry distilling unit;2, raw coke oven gas washing, tar capture unit;3, coal gas convection current list
Unit;4, coal gas dry coke quenching unit.
Detailed description of the invention
In order to the present invention is better described, below in conjunction with the accompanying drawing in the embodiment of the present invention, real to the present invention
The technical scheme executed in example is clearly and completely described.
The present invention includes revolving bed dry distilling unit 1, raw coke oven gas washing, tar capture unit as described in Figure 1
2, coal gas convection unit 3 and coal gas dry coke quenching unit 4, described revolving bed dry distilling unit 1 is sequentially connected with
Raw coke oven gas washing, tar capture unit 2, coal gas convection unit 3 and coal gas dry coke quenching unit 4.
Described revolving bed dry distilling unit 1 is provided with isolation gas radiation pipe, drapery panel and distribution device.Institute
State isolation gas radiation pipe and be arranged on the top of the bed of material, bottom or top and the bottom, be arranged as optimum with bottom,
Because top does not has radial canal can reduce the second pyrolysis reaction of oil gas.Described coal gas dry coke quenching unit 4 is adopted
Use cylinder dry coke quenching auxiliary.The quantity of described cylinder dry coke quenching auxiliary is 1-5 level, it is ensured that semi-coke after quenching
Temperature≤85 DEG C, with 3 grades of quenchings as optimum.It is provided with heat exchange component in described cylinder.Described coal gas pair
Stream unit includes purified gas device and convection flow fan.
Embodiment:
Revolving bed dry distilling unit uses isolation gas radiation pipe heating revolving bed gas retort, treatment scale 100
Ten thousand tons/year, as a example by being pyrolyzed jet coal.
(1) broken feed coal enters revolving bed dry distilling unit, and dry distilling condition is final temperature 650 DEG C, cloth
Material thickness 180mm, the response time 90min rotated a circle, 650 DEG C of semi-coke from furnace side extraction, 650
DEG C oil gas is from furnace roof extraction, furnace roof extraction high temperature oil, gas and water 35.1 ten thousand tons/year.
(2) high temperature oil of extraction, gas and water through gas washing, that tar capture unit carries out coal gas is clean
Changing and collect tar, coal gas and tar temperature are down to 30 DEG C, and circulation purified gas is introduced by convection flow fan
Coal gas dry coke quenching unit, as the cooling medium of semi-coke, collects the tar obtained and purified gas for oil, gas
Product, it is thus achieved that tar product 10.8 ten thousand tons, coal gas product 14.24 ten thousand tons, and finally obtain semi-coke product
64.9 ten thousand tons.Dry coke quenching unit is as a example by 3 grades of quenchings, and one-level dry coke quenching semi-coke inlet temperature is 650 DEG C,
Semi-coke outlet temperature is 550 DEG C, and gas entry temperature is 400 DEG C, and gas outlet temperature is 620 DEG C;
Two grades of dry coke quenching semi-coke inlet temperatures are 550 DEG C, and semi-coke outlet temperature is 300 DEG C, gas entry temperature
Being 250 DEG C, gas outlet temperature is 400 DEG C;Three grades of dry coke quenching semi-coke inlet temperatures are 300 DEG C, blue
Charcoal outlet temperature is≤85 DEG C, and gas entry temperature is 25 DEG C, and gas outlet temperature is 250 DEG C.
(3) cooled coal gas quenching cycle ratio is 0.75, uses the purified gas quenching heat exchange (coal gas after cooling
Dry coke quenching unit heat recovery efficiency reaches 60%), high temperature purified gas convection current pyrolysis raw coal after heat exchange, it is possible to
The high temperature semi-coke sensible heat for pyrolysis unit reclaimed accounts for total combustion gas energy consumption 13.6%.
(4) the high temperature circulation coal gas after dry coke quenching is by the effect of the convection flow fan of coal gas convection unit,
Entered by the burner hearth being positioned at below the bed of material of revolving bed gas retort, the most uniformly worn by distribution device
Cross dry distilling coal seam, it is achieved with the heat convection in coal seam, quickly dry distilling oil gas product is carried outside gas retort simultaneously,
Coal completes dry distillation of coal process under the effect that high temperature circulation coal gas heat convection and radial canal radiate heating.
The above, the only present invention preferably detailed description of the invention, but protection scope of the present invention is not
Being confined to this, any those familiar with the art, can in the technical scope of present disclosure
The change readily occurred in or replacement, all should contain within protection scope of the present invention.Therefore, this
Bright protection domain should be as the criterion with the protection domain of claims.