CN1057064C - Dry recovery technology for material - Google Patents

Abstract

The present invention relates to a drying recovery technology of materials, which can be particularly to applied to the recovery of the byproduct, namely carbon black, generated by the preparation of synthetic gas by using heavy oil as raw materials for gasification in the industry of methanol or synthetic ammonia. Carbon black filter cakes obtained by press filtration and sweep are conveyed to a rotary flash dryer, wherein the water content of the carbon black filter cakes is from 83 to 90%; high-temperature smoke gas at 300 to 900 DEG C is filled; carbon black with high quality and super-high conductivity is obtained by pulverization, rotary flash evaporation, flotation and separation. The technology has the advantages of few equipment, high heat efficiency, good performance of products, no dust emission and good economical and social benefit.

Description

Heavy oil gasifying by product sooty dry recovery technology

The present invention relates to the dried recovered technology of high water-containing materials in the chemical process, particularly produce by product sooty dry recovery technology in methyl alcohol or the synthetic ammonia process.

The present invention is improving and replenishing Chinese patent (patent No. CN 90106273.1) " vaporated carbon black from heavy oil reclaims technology and equipment " patent, this patent is to carry out vacuum-drying through moisture 83～85% soot filter cake after filter-press dehydration and the indirect extrusion under 220～280 ℃ of thermal oils circulations, to obtain carbon black products through steps such as magnetic separation, pulverizing again after the drying.But in actual application, we find this technology particularly thermal oil cyclic drying method exist equipment complexity, failure rate height, thermo-efficiency low (about 20%), energy consumption height, yield poorly, the higher problems such as (greater than 2%) of the carbon black water ratio that produces, for this reason, we improve this technology, indirect extrusion changed into pressurized air purge, and adopt Rotatingandflashstreamingdrier to carry out high temperature drying, receive good effect.

The object of the present invention is to provide a kind of high temperature drying to reclaim the technology of water-containing materials, it is simple that this technology has equipment, processing ease, thermo-efficiency height, characteristics such as product production height, quality are good.

The present invention also aims to provide and reclaim the by product carbon black of producing in methyl alcohol or the synthetic ammonia process by this drying process, this carbon black is the high electric conductivity carbon black, and its key technical indexes meets or exceeds at present famous brand high electric conductivity carbon black Ketjen-blank EC type index in the world.

Technical scheme of the present invention is as follows:

The carbon black waste water (containing carbon black 0.1～3%) that contains that gas making workshop section in methyl alcohol or the synthetic ammonia installation is discharged enters Buffer Pool, gets to close pressing dehydrator with pump again and carries out press filtration, and press filtration pressure is 0.6～2.5MPa, removes the moisture content in the filter cake to greatest extent; With pressure is 0.4～1.5MPa, and the pressurized air that is preferably 0.4～1.0MPa purges remaining moisture content in filter cake, pipeline and the equipment, finally obtains moisture 83～90% soot filter cake; Deliver in the Rotatingandflashstreamingdrier dry with handling equipment again: be delivered into soot filter cake with certain amount from the drying machine middle and lower part, in the drying machine bottom stirring shredder assembly is arranged, be used in time broken and stir block filter cake, enter wet cake in the Rotatingandflashstreamingdrier because the water content height, proportion is bigger, and be lumpy material, directly fall into the broken flashing chamber of drying machine bottom, the stirring wing that broken flashing chamber is equipped with three layers of rotation can be smashed filter cake, big fragment continues to drop to the agitating fins place, the agitating fins that is rotated carries out finished breaking, be stirred filter cake small shreds that wing and agitating fins smash because surface-area increases, heat and mass speed increases considerably, water evaporates speeds up, when producing flashing effect the soot filter cake small shreds by the high-speed and high-temperature flue gas of coming in from drying machine bottom tangential direction (high-temperature flue gas is from the high-temperature flue gas producer, and temperature is 700～1100 ℃ in the stove, pressure in the burner hearth is-10～-30mmH ₂O, high-temperature flue-gas is 300～900 ℃, best high-temperature flue-gas is 300～800 ℃) carrying in the drying machine high speed and rotating, further improve mass-and heat-transfer speed, the sooty proportion that does not reach whole water requirement is bigger, the centrifugal force that rotation produces is also bigger, being thrown to drying machine inwall place rotates along wall, when contacting, produce frictional force with inwall, make of the geometric axis rotation of carbon black fragment around itself, carbon black is crumpled into the bead body, collision mutually between the microsphere, broken, and constantly be dried, progressively moving upward to kiln, rate of drying is further accelerated, proportion constantly reduces, when grain diameter reaches about 0.5mm, water content, reduces to be brought into kiln top by air-flow and partly rotate along the kiln center because moisture content reduces proportion when following less than 1%, the carbon black that conforms to quality requirements can enter the recovery chamber at top by the classification ring, is taken out of Rotatingandflashstreamingdrier by air-flow then and finishes drying process.Foreign material such as the sand grains that may exist in the soot filter cake in drying process, welding slag, iron rust because it can only drop in the trap of drying machine bottom than great and can't rise to and reclaim the chamber, and separatedly fall, so Rotatingandflashstreamingdrier also has flotation function.Dried carbon black enters separating and reclaiming device with air-flow, at first enter the diffusion type cyclonic separator of two parallel connections, bigger particle separates the laggard feed bin of going at this, obtain particulate material, do not separate clean carbon black and enter high temperature cloth bag trap with air-flow, but the cloth bag in the high temperature cloth bag trap and other material heatproof are more than 250 ℃, carbon black separates with air-flow fully at this, isolated carbon black also enters feed bin, obtain looking the finished product carbon black of specific volume more after crushed, separate clean high temperature gas flow and enter atmosphere through induced draft fan greater than 13ml/g.

Technology of the present invention also can be used for dry other aqueous inorganicss.

The present invention changes the indirect extrusion step of former invention with pressurized air into purges, make simple to operate, material consumption and cost reduce, and whole drying process is changed into and is carried out in the Rotatingandflashstreamingdrier, it also has flotation function simultaneously, foreign matter content is compared with the thermal oil mode greatly reduced, thereby simplified drying plant and operation steps, and heat efficiency of the dryer system is brought up to more than 60% by 20% of original thermal oil Recycle design; The product water ratio is reduced to less than 1% by about 2% of original reality, coarse grain part is by original being reduced to more than 0.2% below 0.01%, look specific volume and brought up to more than the 13ml/g by 8 original～12ml/g, every performance index of high electric conductivity carbon black products have met or exceeded the index of best in the world high electric conductivity carbon black Ketjen-blanc EC type; Simultaneously day output is also brought up to 2.8～3.5 tons by original one ton, and moving equipment of total system and consumable accessory significantly reduce, and have simplified operation, made things convenient for maintenance, and dust discharge amount meet national environmental standard in the tail gas, have good economic benefit and social benefit.

Major technique feature of the present invention is to adopt the high water-containing materials of Rotatingandflashstreamingdrier high temperature drying, whole process flow compactness, thermo-efficiency height.With embodiment effect of the present invention is described below.

Embodiment 1:

The sooty water of concentration 0.1～1% is got to close pressing dehydrator (pressure filter) by storage tank through pump, advance to starch pressure 0.8MPa, purge compressed air pressure 1.0MPa, filter cake contains carbon black 15%, then filter cake is delivered in the Rotatingandflashstreamingdrier with two-screw conveyer (rotating speed is 500rpm), (temperature is 900 ℃ in the stove, pressure in the burner hearth-20 mmH by the high-temperature flue gas producer ₂O) high-temperature flue gas of Chan Shenging is directly introduced the bottom (this moment, high-temperature flue-gas was 800 ℃) of drying machine, dry carbon black to grain diameter reaches about 0.5mm, water content is separated, pulverizes, is packed when following less than 1%, and institute's carbon black performance index that obtain and former thermal oil desiccating method obtain carbon black performance index and Ketjen-blank EC type carbon black index and contrast and see Table 1.The carbon black performance is supervised inspection center by national carbon black mass and is detected.

Table 1. carbon black performance comparison

Project	Unit	Embodiment 1	Thermal oil carbon black that desiccating method obtains	Ketjen-blank EC type carbon black
					Particle diameter	nm	37	33	30
Iodine absorption value	g/kg	1102	944	900
					The DBP absorption value	ml/100g	5.68	5.86	3.6
The CTAB adsorption specific surface area	m 2/g	1544	828	500
					The nitrogen adsorption specific surface area	m 2/g	1100	1080	950
PH value		8.6	8.0	7～10
					Moisture content	％	＜1	6.2	1
Ash	％	2.8	1.0	1
					Impurity		Do not have	0.02	0.03
Compare resistance	Ω·m	2.2	2.7
					Look specific volume	ml/g	16	6.2	7.1
The hydrochloric acid liquid absorption	ml/g	5.9	4.0
					Fugitive constituent	％	4.3	2.9	1

Claims (3)

1. heavy oil gasifying by product sooty dry recovery technology, the carbon black water that produces that will gasify earlier absorbs the sooty water that obtains containing carbon black 0.1～3%, carries out press filtration through pressure filter then, and drying, Separation and Recovery carbon black again is characterized in that:

A. the filter cake pressure that press filtration is produced is that the pressurized air of 0.4～1.5MPa purges, and obtains moisture 83～90% soot filter cake;

B. the soot filter cake that step a is obtained carries out drying in Rotatingandflashstreamingdrier, and soot filter cake obtains the high electric conductivity carbon black through pulverizing, rotary flash distillation, flotation, separation in this Rotatingandflashstreamingdrier, and dry used high-temperature flue-gas is 300～900 ℃.

2. technology as claimed in claim 1 is characterized in that filter cake that press filtration is produced purges with the pressurized air of 0.4～1.0MPa.

3. technology as claimed in claim 1 is characterized in that dry used high-temperature flue-gas is 300～800 ℃.