CN104003396B

CN104003396B - Prepare the method and system of polysilicon and the method and system of purify trichlorosilane

Info

Publication number: CN104003396B
Application number: CN201410260437.9A
Authority: CN
Inventors: 李锋; 王利强; 张艳春; 濮希杰; 张晓峰; 高阳; 隋永亮; 庄志远
Original assignee: State's Electricity Inner Mongol Jing Yang Ltd Energy Co
Current assignee: State's Electricity Inner Mongol Jing Yang Ltd Energy Co
Priority date: 2014-06-12
Filing date: 2014-06-12
Publication date: 2016-05-18
Anticipated expiration: 2034-06-12
Also published as: CN104003396A

Abstract

The present invention proposes and prepare the system and method for polysilicon and the method and system of purify trichlorosilane. Wherein, the method of preparing polysilicon comprises: (1) utilizes hot water respectively hydrogen and trichlorosilane to be heated, to obtain hydrogen and trichlorosilane through overcooled hot water and process heat treated, (2) make, through hydrogen and the trichlorosilane of heat treated, reduction reaction occurs in reduction furnace, to obtain polysilicon and reduction tail gas, described reduction furnace carried out water-cooled and obtains the first hot water; (3) utilize reduction tail gas to heating through overcooled hot water and obtaining the second hot water; And the first hot water and the second hot water is mixed to get reduction workshop section hot water by (4), and thermal source using reduction workshop section hot water as rectifying column is for purify trichlorosilane, so that the workshop section that obtains purifying returns to water; Wherein, the first hot water and the second hot water are 145～155 degrees Celsius. Utilize said method can realize recycling of water resource and heat energy, and then significantly save energy consumption.

Description

Prepare the method and system of polysilicon and the method and system of purify trichlorosilane

Technical field

The present invention relates to field polysilicon, particularly, the present invention relates to prepare the method and system of polysilicon and purify threeThe method and system of chlorine hydrogen silicon.

Background technology

In existing production of polysilicon, especially in the preparation of polysilicon and the purifying technique of trichlorosilane, all need a large amount of waterResource, thermal source and low-temperature receiver, cause the production of polysilicon to have the defect that energy consumption is good, cost is high. Therefore, existing relevantProduction of polysilicon technique still needs further improvement.

Summary of the invention

The present invention is intended to solve at least to a certain extent one of technical problem in correlation technique. For this reason, one of the present inventionObject is to propose to prepare the method and system of polysilicon and the method and system of purify trichlorosilane, utilizes above-mentioned two kinds of methodsCan be undertaken preparing thermal source in the reduction furnace cooling water that uses in polysilicon and heating raw materials water and purify trichlorosilane with systemCoupling, and then make full use of water resource and save energy consumption.

According to an aspect of the present invention, the method for preparing polysilicon of the embodiment of the present invention comprises:

(1) utilize hot water respectively hydrogen and trichlorosilane to be heated, to obtain through overcooled hot water with through heatingHydrogen and the trichlorosilane processed,

(2) hydrogen and the trichlorosilane of the described process heat treated obtaining in step (1) are also occurred more in reduction furnaceFormer reaction, to obtain polysilicon and reduction tail gas, wherein, in reduction reaction process, carries out water-cooled to described reduction furnace,And obtain the first hot water;

(3) utilize described reduction tail gas to heating through overcooled hot water of obtaining in step (1), to obtainThe second hot water; And

(4) described the first hot water and described the second hot water are mixed, to obtain reducing workshop section's hot water, and go back describedFormer workshop section hot water is used for purify trichlorosilane as the thermal source of rectifying column, so that the workshop section that obtains purifying returns to water;

Wherein, the temperature of described the first hot water and described the second hot water is respectively independently within the scope of 145～155 degrees Celsius.

In addition, the method for preparing polysilicon according to the above embodiment of the present invention can also have following additional technical characterictic:

In some embodiments of the invention, the hot water temperature who adopts in step (1) is 130 degrees Celsius, in step (2)The water that middle employing the is 130 degrees Celsius respectively chassis to described reduction furnace and chuck carries out described water-cooled.

In some embodiments of the invention, described is 110 degrees Celsius through the hydrogen of heat treated and the temperature of trichlorosilane,And before the described hydrogen through heat treated obtaining in step (1) and trichlorosilane are incorporated into described reduction furnace,Adopt in advance described reduction tail gas to be preheated to 180 degrees Celsius.

In some embodiments of the invention, in above-mentioned steps (4), comprising:

Make-up water and described reduction workshop section hot water are mixed, and after obtained mixing water is heated to 150 degrees Celsius as smartHeat up in a steamer the thermal source of tower.

In some embodiments of the invention, described make-up water obtains through the following steps:

(4-1) a described part of reducing workshop section's hot water is used for to purify trichlorosilane as the thermal source of rectifying column, obtains simultaneouslyPurification workshop section returns to water, and

(4-2) Part II of described reduction workshop section hot water is carried out after water-cooled and the 3rd that is selected from described reduction workshop section hot waterPoint and described purification workshop section at least a portion of returning to water mix, be the described benefit of 130 degrees Celsius to obtain temperatureFeedwater.

In some embodiments of the invention, in step (4), further comprise

(4-1) the described Part I that reduces workshop section's hot water is used for to purify trichlorosilane as the thermal source of rectifying column, simultaneouslyTo purification, workshop section returns to water;

(4-2) Part II of described reduction workshop section hot water is carried out after water-cooled and the 3rd that is selected from described reduction workshop section hot waterPoint and described purification workshop section at least a portion of returning to water mix, be the water of 130 degrees Celsius to obtain temperature;

(4-3) water that is 130 degrees Celsius using the temperature obtaining in step (4-2) is heated to 150 degrees Celsius as rectifying columnThermal source is for purify trichlorosilane.

According to a further aspect in the invention, the method for the purify trichlorosilane of the embodiment of the present invention, described trichlorosilane contains twoChlorine dihydro silicon and tetrachloro hydrogen silicon, is characterized in that, described method comprises:

(1) described trichlorosilane is carried out to the first rectification process, to obtain trichlorosilane, the first condensate liquid, the first condensationRear gas and the first liquid heavy constituent, wherein, after described the first condensation, liquid contains dichloro-dihydro silicon and trichlorosilane, and described firstIn liquid state, component contains tetrachloro hydrogen silicon and trichlorosilane;

(2) described the first liquid heavy constituent is carried out to the second rectification process, to obtain after liquid after the second condensation, the second condensationPhase and the second liquid heavy constituent, wherein, after described the second condensation, liquid contains silicon tetrachloride;

(3) by gas after gas after described the first condensation and described the second condensation one of at least carry out condensation process, to obtain theGas after liquid and the 3rd condensation after three condensations; And

(4) by liquid after liquid after described the first condensation and described the 3rd condensation one of at least carry out the 3rd rectification process, to obtainGas and the 3rd liquid heavy constituent after liquid, the 4th condensation after the 4th condensation, wherein, after described the 4th condensation, liquid contains dichloro twoHydrogen silicon, described the 3rd liquid heavy constituent contains trichlorosilane,

Wherein, the thermal source one of at least of described the first rectification process, the second rectification process, the 3rd rectification process is reduction workSection hot water, and described reduction workshop section hot water is by following acquisition:

(2) hydrogen and the trichlorosilane of the described process heat treated obtaining in step (1) are also occurred in reduction furnaceFormer reaction, to obtain polysilicon and reduction furnace tail gas, wherein, in reduction reaction process, carries out water to described reduction furnaceCold, and obtain the first hot water;

(4) described the first hot water and described the second hot water are mixed, to obtain reducing workshop section's hot water, wherein, described firstThe temperature of hot water and described the second hot water is respectively independently in the scope of 145～155 degrees Celsius.

In accordance with a further aspect of the present invention, the system of preparing polysilicon of the embodiment of the present invention, comprising:

Hydrogen heater and trichlorosilane heater, described hydrogen heater and trichlorosilane add heat utilization hot water respectivelyHydrogen and trichlorosilane are heated, to obtain hydrogen and the trichlorosilane through overcooled hot water and process heat treated;

Reduction furnace, described reduction furnace is connected with trichlorosilane heater with described hydrogen heater respectively, described in makingIn reduction furnace, there is reduction reaction in hydrogen and trichlorosilane through heat treated, to obtain polysilicon and reduction furnace tail gas,Wherein, described reduction furnace has water-cooled assembly, and described reduction furnace is carried out to water-cooled, and obtains the first hot water:

Gas-liquid heat-exchange device, described gas-liquid exchange device respectively with described hydrogen heater, trichlorosilane heater andReduction furnace is connected, for utilizing described reduction tail gas to heat through overcooled hot water described, to obtain the second hot water;And

Hot water mixing arrangement, described hot water mixing arrangement is connected with described gas-liquid heat-exchange device with described reduction furnace respectively, usesIn described the first hot water and described the second hot water are mixed, to obtain reducing workshop section's hot water;

Trichlorosilane purification devices, described trichlorosilane purification devices comprises rectifying column, and described rectifying column and described hot waterMixing arrangement is connected, and the thermal source using described reduction workshop section hot water as rectifying column, is purified for use in purify trichlorosilaneWorkshop section returns to water; Described trichlorosilane purification devices and described hydrogen heater, trichlorosilane heater and reduction furnace phaseConnect, to utilize described pure workshop section to return to water respectively to described hydrogen with trichlorosilane heats and described reduction furnace is carried outWater-cooled.

In addition, the system of preparing polysilicon according to the above embodiment of the present invention can also have following additional technical characterictic:

In some embodiments of the invention, the above-mentioned system of preparing polysilicon further comprises:

Gas gas heat-exchange device, described gas gas heat-exchange device respectively with described hydrogen heater, trichlorosilane heater,Reduction furnace and gas-liquid heat-exchange device are connected, and described is 110 Celsius through the hydrogen of heat treated and the temperature of trichlorosilaneDegree, to obtain before described hydrogen through heat treated and trichlorosilane be incorporated into described reduction furnace, described in adopting in advanceReduction furnace is preheated to 180 degrees Celsius.

In some embodiments of the invention, further comprise:

Make-up water device, described make-up water device is connected with described hot water mixing arrangement, so that in described reduction workshop section hot waterAdd make-up water.

Heater, described heater is connected with described hot water mixing arrangement, so that by the reduction of adding after described make-up waterAfter workshop section's hot water heating to 150 degree Celsius and as the thermal source of rectifying column.

In some embodiments of the invention, further comprise:

Cooling device, described cooling device is connected with device for supplying with described hot water mixing arrangement, so that by described reduction workshop sectionThe Part I of hot water is used for purify trichlorosilane as the thermal source of rectifying column, and the workshop section that simultaneously obtains purifying returns to water; And willThe Part II of described reduction workshop section hot water carry out cooling after be selected from described reduction workshop section hot water Part III and described in carryPure workshop section returns to one of at least mixing of water, is the described make-up water of 130 degrees Celsius to obtain temperature.

In some embodiments of the invention, described cooling device, described cooling device and described hot water mixing arrangement, hydrogenHeater, trichlorosilane heater and reduction furnace are connected, so as using the Part I of described reduction workshop section hot water asThe thermal source of rectifying column is for purify trichlorosilane, and the workshop section that simultaneously obtains purifying returns to water; By described second of the workshop section's hot water that reducesPart carry out cooling after be selected from the Part III of described reduction workshop section hot water and described purification workshop section return water one of at leastMixing, is the water of 130 degrees Celsius to obtain temperature; And by obtained temperature be 130 degrees Celsius water for pointOther to described hydrogen with trichlorosilane heats and described reduction furnace is carried out to water-cooled.

In some embodiments of the invention, described make-up water device further comprises:

Constant pressure tank, described Constant pressure tank is connected with described hot water mixing arrangement;

Constant pressure tank;

Constant pressure pump, described constant pressure pump is arranged between described Constant pressure tank and described constant pressure tank;

Pressure gauge, described Pressure gauge is connected with described Constant pressure tank and is arranged on a side of the delivery port of proximity thermal water mixing device.

According to a further aspect of the invention, the system of the purify trichlorosilane of the embodiment of the present invention, described trichlorosilane containsDichloro-dihydro silicon and silicon tetrachloride, described system comprises:

The first rectification cell, described the first rectification cell is for described trichlorosilane is carried out to the first rectification process, to obtainGas and the first liquid heavy constituent after liquid, the first condensation after trichlorosilane, the first condensation, wherein, after described the first condensation, liquid containsHave dichloro-dihydro silicon and trichlorosilane, described the first liquid heavy constituent contains silicon tetrachloride and trichlorosilane;

The second rectifier unit, described the second rectifier unit is connected with described the first rectification cell, for liquid heavy to described firstComponent is carried out the second rectification process, to obtain gas and the second liquid heavy constituent after liquid after the second condensation, the second condensation, wherein,After described the second condensation, liquid contains silicon tetrachloride;

Condensing unit, described condensing unit is connected with described the second rectifier unit with described the first rectification cell, for to describedAfter the first condensation after gas and described the second condensation gas one of at least carry out condensation process, to obtain after the 3rd condensation liquid and theGas after three condensations; And

The 3rd rectifier unit, described the 3rd rectifier unit is connected with described condensing unit with described the first rectification cell, for rightAfter described the first condensation after liquid and described the 3rd condensation liquid one of at least carry out the 3rd rectification process, to obtain the 4th condensationGas and the 3rd liquid heavy constituent after rear liquid, the 4th condensation, wherein, after described the 4th condensation, liquid contains dichloro-dihydro silicon, described inThe 3rd liquid heavy constituent contains trichlorosilane;

Wherein, the thermal source one of at least of described the first rectification cell, the second rectifier unit, the 3rd rectifier unit is reduction workSection hot water, and described reduction workshop section hot water is from the system of preparing polysilicon, and described polysilicon system comprises:

Hot water mixing arrangement, described hot water mixing arrangement is connected with described gas-liquid heat-exchange device with described reduction furnace respectively, usesIn described the first hot water and described the second hot water are mixed, to obtain reducing workshop section's hot water.

Brief description of the drawings

Fig. 1 is the flow chart of the method for purify trichlorosilane according to an embodiment of the invention.

Fig. 2 is the structural representation of preparing according to an embodiment of the invention the system of polysilicon.

Fig. 3 is the structural representation of preparing in accordance with another embodiment of the present invention the system of polysilicon.

Fig. 4 is the structural representation of the system of preparing polysilicon of another embodiment according to the present invention.

Fig. 5 is the structural representation of the system of purify trichlorosilane according to an embodiment of the invention.

Fig. 6 is the method flow diagram of preparing according to an embodiment of the invention polysilicon.

Fig. 7 is the method flow diagram of preparing according to an embodiment of the invention polysilicon.

Detailed description of the invention

Describe embodiments of the invention below in detail, the example of described embodiment is shown in the drawings, wherein identical from start to finishOr similarly label represents same or similar element or has the element of identical or similar functions. Below by retouching with reference to accompanying drawingThe embodiment stating is exemplary, is intended to for explaining the present invention, and can not be interpreted as limitation of the present invention.

The method of preparing according to an embodiment of the invention polysilicon specifically comprises the following steps:

Commonly in the production of polysilicon, need a large amount of water resources, for example, raw hydrogen and trichlorosilane are heatedHot water, carries out cooling cooling water and needs a large amount of thermals source to the trichlorosilane purification of boiling again reduction furnace, therefore thisBright inventor finds, if will pass through heat between the water required purification of water and trichlorosilane in the preparation process of polysiliconThe carrying out coupling of amount and the water yield recycles, and not only can save a large amount of water resources, and the while can also save extra coolingWith heating energy consumption. But the number of opening or moving due to reduction furnace can change constantly, and purify trichlorosilane is usedThe number of rectifying column is unstable, is difficult to meet institute's water requirement and water temperature in two techniques, therefore the water in two techniques is carried outRecycle tool great difficulty.

According to an embodiment of the invention, the hot water temperature who adopts in above-mentioned steps (1) is 130 degrees Celsius, in step(2) chassis to reduction furnace and chuck carry out described water-cooled respectively in, to adopt the water of 130 degrees Celsius. That is to say and prepare polycrystallineThe needed coolant-temperature gage of silicon all can be 130 degrees Celsius, and the temperature of the reduction workshop section hot water obtaining after heating and water-cooledDegree is 145～155 degrees Celsius, and the hot water of this temperature can be further used as rectifying column thermal source for purify trichlorosilane. InventionPeople also finds, the temperature that the purification workshop section obtaining after heating rectifying column returns to water is about 130 degrees Celsius, is also just being used onThe heat treated of the cooling and raw material of the reduction furnace of former reaction, thereby reached hot water temperature's coupling. The present inventor justBe to have found above-mentioned two temperature, can be about 150 degrees Celsius for rectifying column heating with hot water, after rectifying column heatingNear 130 degrees Celsius of temperature, further returns for the preparation of polysilicon, utilizes the further water to reduction workshop section of reduction tail gasHeat and finally obtain 150 degrees Celsius of water again for purify trichlorosilane, and then reach the coupling of coolant-temperature gage.

According to a particular embodiment of the invention, be 110 degrees Celsius through the hydrogen of heat treated and the temperature of trichlorosilane, andAnd before the hydrogen of the process heat treated obtaining in step (1) and trichlorosilane are incorporated into reduction furnace, adopt in advanceReduction tail gas is preheated to 180 degrees Celsius. Can make full use of thus the heat energy of reduction tail gas, improve the effect of reduction reactionRate. According to a particular embodiment of the invention, after first reduction tail gas heat hydrogen and trichlorosilane, right furtherAbove-mentionedly after being heated, hydrogen and trichlorosilane carry out preheating and then obtain temperature being about 150 Celsius through overcooled hot waterThe hot water of degree. The present invention takes the photograph the hot water heating of reduction workshop section by the heat energy that makes full use of reduction tail gas to being about 150 thusFamily name's degree, and then be applicable to purify trichlorosilane, provide guarantee for preparing polysilicon process water circulation.

According to a particular embodiment of the invention, in above-mentioned steps (4), can further include: by make-up water and reduction workSection hot water mixes, and obtained mixing water is heated to the thermal source as rectifying column after 150 degrees Celsius. Can ensure thusIn the time that the water yield of reduction workshop section hot water can not meet in purifying technique institute's water consumption, lack to supply in reduction workshop section hot water in timeThe water yield. According to a particular embodiment of the invention, can adopt Pressure gauge monitor constantly reduction workshop section's hot water and purification workshop section itBetween the pressure of water, and then judge that whether the water yield not enough. Simultaneously Pressure gauge with determine power pump and constant pressure tank and be connected, Jin ErgenAccording to Pressure gauge pressure changing make-up water in trend reduction workshop section hot water. Can avoid thus because output deficiency causesRectifying column fluctuation for purify trichlorosilane is large, affects product quality.

According to a particular embodiment of the invention, first above-mentioned make-up water obtains through the following steps:

(4-1) thermal source using a part for reduction workshop section hot water as rectifying column, for purify trichlorosilane, is purified simultaneouslyWorkshop section returns to water, and

According to a particular embodiment of the invention, in the time of hot water amount described in the amount of reduction workshop section hot water has exceeded purify trichlorosilane,The method of preparing polysilicon of the above embodiment of the present invention can also reach the coupling of the water yield through the following steps. According to the present inventionSpecific embodiment, in above-mentioned steps (4), can further include:

(4-1) thermal source using the Part I of reduction workshop section hot water as rectifying column, for purify trichlorosilane, is carried simultaneouslyPure workshop section returns to water;

(4-2) Part II of reduction workshop section hot water carried out after water-cooled and be selected from the Part III of reduction workshop section hot water and carryPure workshop section returns at least a portion of water to be mixed, and is the water of 130 degrees Celsius to obtain temperature.

Thus, again return to water with purification workshop section by the water that obtains 130 degrees Celsius after the water of redundance is lowered the temperatureReturn to and heating raw material cooling for reduction furnace. And the present invention is by entering the sub-fraction of unnecessary reduction workshop section hot waterAfter row is cooling and another part be mixed to get the water of 130 degrees Celsius, and then can save cooling energy consumption.

By adopting the method for preparing polysilicon of the above embodiment of the present invention, when the reduction hot water amount of workshop section and purification workWhen Duan Shuiliang is identical, only need in advance this water be heated to after 130 degrees Celsius, in follow-up cyclic process, only needThe heat that makes full use of reduction tail gas can arrive whole fresh water (FW) circulation, without extra heat, cold and extraMake-up water. Can significantly save thus the water yield and energy consumption.

By adopting the method for preparing polysilicon of the above embodiment of the present invention, when being less than, the reduction workshop section hot water water yield carriesWhen the pure workshop section water yield, can change after automatically adding make-up water in reduction workshop section hot water and again carry out by monitor forceBe heated to approximately 150 degrees Celsius, and then avoid affecting the quality of purification workshop section trichlorosilane.

By adopting the method for preparing polysilicon of the above embodiment of the present invention, when the reduction workshop section water yield more than with purificationWhen the workshop section water yield, by unnecessary hot water is divided into two parts, a part is wherein carried out cooling, and then make manyAfter remaining hot water temperature is down to 130 degrees Celsius again for reducing workshop section.

According to a further aspect in the invention, the present invention proposes a kind of method of purify trichlorosilane, in described trichlorosilane, containThere are dichloro-dihydro silicon and tetrachloro hydrogen silicon. Comprise according to the method for the purify trichlorosilane of the embodiment of the present invention:

Describe the method for the purify trichlorosilane of the above embodiment of the present invention in detail below with reference to Fig. 1.

S100: the first rectification process

According to embodiments of the invention, trichlorosilane carries out the first rectification process, thereby can obtain respectively trichlorosilane,Gas and the first liquid heavy constituent after liquid, the first condensation after one condensation. According to embodiments of the invention, after the first condensation, liquid canContain dichloro-dihydro silicon and trichlorosilane, the first liquid heavy constituent can contain silicon tetrachloride and trichlorosilane. According to the present inventionEmbodiment, can adopt the rectifying column of multiple series connection to carry out the first rectification process, according to a particular embodiment of the invention, canCarry out the first rectification process with the rectifying column that adopts five series connection. According to concrete example of the present invention, the rectifying column of five series connectionComprise the first to the 5th rectifying column, and each includes: liquid outlet at the bottom of the outlet of tower body, tower overhead gas, tower, charging aperture,Condensation separator, heater, wherein, limit rectifying space in tower body, be suitable for the material in rectifying space to carry out rectifyingProcess, thereby can obtain respectively liquid and tower overhead gas at the bottom of tower; Tower overhead gas outlet is arranged on the top of tower body, is suitable for exporting tower topGas; At the bottom of tower, liquid outlet is arranged on the bottom of tower body, is suitable for exporting liquid at the bottom of tower; Charging aperture is arranged on tower body, is suitable for to rectifyingIn space, introduce the material for the treatment of rectifying; Condensation separator is connected with tower overhead gas outlet, is suitable for tower overhead gas to carry out condensation separation placeReason, thus condensing gas and condensate liquid can be obtained; Heater is connected with tower body, is suitable for rectifying space to heat.

Concrete, by heater, heat treated is carried out in the first rectifying column rectifying space, then by charging aperture to rectifying skyBetween in add trichlorosilane (coarse fodder that contains 85% left and right trichlorosilane), the light component that makes to contain a large amount of dichloro-dihydro silicon andThe mist of lower boiling impurity is discharged from top gas outlet, then mist is carried out to condensation through condensation separator and dividesFrom processing, thus after the first rectifying column condensation that can obtain respectively containing dichloro-dihydro silicon and trichlorosilane liquid and the first essenceHeat up in a steamer gas after tower condensation, and heavy constituent and high boiling impurity as the first rectifying tower at the bottom of liquid discharge from the outlet of furnace bottom liquid. According toEmbodiments of the invention, the first rectifying column can be high-efficiency guide sieve-plate tower, and tower internal diameter is 1500mm, and the number of plates is 76,Charging aperture is 32nd～55 blocks of column plates, and tower top operating pressure is 0.245MPaG, and operating temperature is 71～73 DEG C, tower reactor operationPressure is 0.298MPaG, and operating temperature is 77～79 DEG C, and reflux ratio is 133.5. At the bottom of the first rectifying tower, liquid is as the second essenceThe rectifying material for the treatment of that heats up in a steamer tower carries out rectification process, can remove most of heavy constituent silicon tetrachloride and high-boiling-point impurity, thereby canTo obtain respectively after liquid after Second distillation column condensation, Second distillation column condensation liquid at the bottom of gas and Second distillation column tower. According to the present inventionEmbodiment, Second distillation column can be high-efficiency guide sieve-plate tower, tower internal diameter is 1500mm, the number of plates is 76, chargingMouth is 32nd～55 blocks of column plates, and tower top operating pressure is 0.243MPaG, and operating temperature is 71～73 DEG C, tower reactor operating pressureFor 0.297MPaG, operating temperature is 84～87 DEG C, and reflux ratio is 14.5. After Second distillation column condensation, liquid is as the 3rd rectifyingThe rectifying material for the treatment of of tower carries out rectification process, can further remove light component impurity residual in material, makes light group in materialPoint impurity content reaches the requirement of electron level trichlorosilane, thereby can obtain respectively liquid after the 3rd rectifying column condensation, the 3rd rectifyingLiquid at the bottom of gas and the 3rd rectifying tower after tower condensation. According to embodiments of the invention, the 3rd rectifying column can be high efficiency guide sieveTower, tower internal diameter is 1500mm, and the number of plates is 76, and charging aperture is 32nd～55 blocks of column plates, and tower top operating pressure is0.25MPaG, operating temperature is 71～73 DEG C, and tower reactor operating pressure is 0.304MPaG, and operating temperature is 77～79 DEG C, returnsStream is than being 128.5. At the bottom of the 3rd rectifying tower, liquid treats that as the 4th rectifying column rectifying material carries out rectification process, can remove materialIn the heavy constituent impurity of middle remnants, thereby can obtain respectively gas after liquid after the 4th rectifying column condensation, the 4th rectifying column condensationWith liquid at the bottom of the 4th rectifying tower. According to embodiments of the invention, the 4th rectifying column can be high-efficiency guide sieve-plate tower, tower internal diameterFor 1500mm, the number of plates is 76, and charging aperture is that 32nd～55 blocks of column plates go out, and tower top operating pressure is 0.250MPaG,Operating temperature is 71～73 DEG C, and tower reactor operating pressure 0.303MPaG is, operating temperature is 77～79 DEG C, and reflux ratio is 18.After the 4th rectifying column condensation, liquid carries out rectification process as the rectifying material for the treatment of of the 5th rectifying column, can further remove in materialRemaining heavy constituent impurity, thus gas and the 5th rectifying after liquid after the 5th rectifying column condensation, the 5th rectifying column condensation can be obtainedLiquid at the bottom of tower tower. According to embodiments of the invention, the 5th rectifying column can be high-efficiency guide sieve-plate tower, and tower internal diameter is 1500mm,The number of plates is 76, and charging aperture is 32nd～55 blocks of column plates, and tower top operating pressure is 0.246MPaG, and operating temperature is71～73 DEG C, tower reactor operating pressure is 0.298MPaG, and operating temperature is 77～79 DEG C, and reflux ratio is 20.

According to embodiments of the invention, by first to liquid outlet at the bottom of the tower of the 5th rectifying column one of at least with the first rectifying columnCharging aperture is connected, to make at the bottom of tower that the second to the 5th rectifying column one of at least discharges liquid as the rectifying for the treatment of of the first rectifying columnMaterial uses. For example, can return as the treating rectifying material of the first rectifying column using the 4th to liquid at the bottom of the tower of the 5th rectifying column andUse. Particularly, at the bottom of tower, in liquid, contain the trichlorosilane of part, by liquid at the bottom of tower is returned and proceeds rectification process, canTo significantly improve the utilization rate of material.

S200: the second rectification process

According to embodiments of the invention, the liquid heavy constituent of above gained first is carried out to the second rectification process, thereby can obtainGas and the second liquid heavy constituent after liquid, the second condensation after the second condensation. According to embodiments of the invention, after the second condensation in liquidContain silicon tetrachloride. According to a particular embodiment of the invention, liquid at the bottom of the first to the 5th rectifying column tower one of at least can be enteredRow the second rectification process, for example, can carry out the second rectification process as the first liquid heavy constituent using liquid at the bottom of Second distillation column tower.According to embodiments of the invention, the second liquid restructuring is divided into waste liquid, can directly be delivered to liquid waste processing operation and process.Inventor finds, contains silicon tetrachloride and a large amount of heavy constituent impurity, by carrying out the second rectifying at the bottom of Second distillation column tower in liquidMost heavy constituent impurity can be effectively removed in processing, thereby can obtain finished product silicon tetrachloride. Particularly, the second rectifyingTreating apparatus can be high-efficiency guide sieve-plate tower, and tower internal diameter is 2200mm, and the number of plates is 60, and charging aperture is 25th～45Piece column plate, tower top operating pressure is 0.213MPaG, and operating temperature is 89～92 DEG C, and tower reactor operating pressure is 0.223MPaG,Operating temperature is 128～131 DEG C, and reflux ratio is 4.5.

S300: condensation process

According to embodiments of the invention, gas after gas and the second condensation after above gained the first condensation one of at least carried out to condensationProcess, thereby can obtain after the 3rd condensation gas after liquid and the 3rd condensation. According to embodiments of the invention, the bar of condensation processPart is also not particularly limited, and according to a particular embodiment of the invention, condensation process can be-40～-38 degrees Celsius and press in temperaturePower is to carry out under the condition of 0.1～0.15MPaG. Inventor's discovery, the condensation process of carrying out under this condition can obviously improve coldThe separative efficiency of liquid after gas and condensation after solidifying. According to embodiments of the invention, can by the first to the 5th rectifying column at least itOne produce condensation after gas as the first condensation after gas carry out condensation process. Inventor finds, gas and second cold after the first condensationAfter solidifying, in gas, contain a large amount of dichloro-dihydro silicon and a small amount of trichlorosilane, carried out carrying out again subsequent treatment after condensation process,Can significantly improve the utilization rate of material, can reduce exhaust emissions amount simultaneously. According to embodiments of the invention, the 3rd condensationIn rear gas, contain on-condensible gas, can directly be sent to exhaust-gas treatment operation and process. According to a particular embodiment of the invention,The device of condensation process can be double tubesheet tubular heat exchanger, and heat exchanger tube pass fluid is gas after each tower condensation, shell-side fluidFor-38 DEG C of chilled brines, in upper cover, there is a pass partition, dividing plate one side has gas inlet port after each tower condensation, and opposite side hasOn-condensible gas floss hole, low head has a condensate discharge mouth.

S400: the 3rd rectification process

According to embodiments of the invention, by liquid after liquid after the first condensation and the 3rd condensation one of at least carry out the 3rd rectification process,Thereby can obtain gas and the 3rd liquid heavy constituent after liquid after the 4th condensation, the 4th condensation. According to a particular embodiment of the invention,After the 4th condensation, in liquid, contain dichloro-dihydro silicon, the 3rd liquid heavy constituent contains trichlorosilane. According to embodiments of the invention,After the condensation can the using first to the 5th rectifying column one of at least producing, liquid liquid after the first condensation carries out the 3rd rectification process.For example, can by first and the 3rd after the condensation that produces of rectifying column after liquid and the 3rd condensation liquid carry out the 3rd rectification process. InventionPeople finds, in the first and the 3rd liquid after rectifying column condensation, contain more than 99% trichlorosilane, the dichloro-dihydro silicon less than 1% withAnd a large amount of light component impurity (as the compound of boron), can remove the major part two in light component material by the 3rd rectification processChlorine dihydro silicon and low boiling impurity, and passable through trichlorosilane content in the 3rd rectification process gained the 3rd liquid heavy constituentReach more than 99.99%. According to embodiments of the invention, the 3rd rectifier unit can be high-efficiency guide sieve-plate tower, and tower internal diameter is1200mm, the number of plates is 76, and charging aperture is 32nd～55 blocks of column plates, and tower top operating pressure is 0.248MPaG, operationTemperature is 55～58 DEG C, and tower reactor operating pressure is 0.298MPaG, and operating temperature is 77～79 DEG C, and reflux ratio is 47.

Can prepare the required trichlorosilane of electronic-grade polycrystalline silicon according to the method for the purify trichlorosilane of the embodiment of the present invention,And by gas centralized recovery after gas and the second condensation after the condensation that the first to the 5th rectifying column is produced, and by gas collection after condensationIn carry out condensation process, can obviously reduce the consumption of cold and the discharge of tail gas, simultaneously by the bottom of Second distillation column tower liquid continueCarry out rectification process, can obtain silicon tetrachloride product, in addition, the condensation that the first to the 5th rectifying column one of is at least producedAfter rear liquid and the 3rd condensation, liquid is proceeded rectification process, can effectively trichlorosilane wherein and dichloro-dihydro silicon be dividedFrom.

According to a particular embodiment of the invention, above-mentioned for the first to the 5th rectifying column of the first rectification process with for the second essenceHeat up in a steamer and process and the rectifying column of the 3rd rectification process thermal source one of at least can adopt reduction workshop section hot water, and reduce workshop section's heatWater is by following acquisition:

(2) make the hydrogen of the process heat treated obtaining in step (1) and trichlorosilane reduction occur in reduction furnace insteadShould, to obtain polysilicon and reduction furnace tail gas, wherein, in reduction reaction process, reduction furnace is carried out to water-cooled, andObtain the first hot water;

(3) utilize reduction tail gas to heating through overcooled hot water of obtaining in step (1), to obtain secondHot water; And

(4) the first hot water and described the second hot water are mixed, to obtain reducing workshop section's hot water, wherein, the first hot water and instituteState the temperature of the second hot water respectively independently in the scope of 145～155 degrees Celsius.

Thus the present invention by the reduction workshop section hot water that produces in preparing polysilicon as the thermal source of rectifying column for the trichlorine of purifyingHydrogen silicon, and the present invention makes full use of reduction tail gas heat quantity, and to make the temperature of the reduction workshop section hot water finally obtaining be 145～155Degree Celsius, and then can meet the requirement of purify trichlorosilane technique to coolant-temperature gage. The purification of the above embodiment of the present inventionThe method of trichlorosilane adopts reduction workshop section hot water to heat rectifying column, can save a large amount of water resources and heat energy. EspeciallyThe temperature of the hot water of its reduction workshop section is 145～155 degrees Celsius, can effectively maintain the rectifying adopting in purify trichlorosilaneThe stability of tower, and then ensure that product quality is unaffected. In addition, the polysilicon prepared according to the above embodiment of the present inventionBeneficial effect in method is equally applicable to the method for the purify trichlorosilane of above-described embodiment, does not repeat them here.

According to a further aspect of the invention, the invention allows for a kind of system of preparing polysilicon, detailed below with reference to Fig. 2The thin system of preparing polysilicon of describing the embodiment of the present invention.

As shown in Figure 2, the system of preparing polysilicon of the embodiment of the present invention comprises: hydrogen heater 100, trichlorosilane addHot charging puts 200, reduction furnace 300, gas-liquid heat-exchange device 400, hot water mixing arrangement 500 and trichlorosilane purification devices 600.

Wherein, hydrogen heater 100 and trichlorosilane heater 200 utilize hot water respectively hydrogen and trichlorosilane to be enteredRow heating, to obtain hydrogen and the trichlorosilane through overcooled hot water and process heat treated;

Reduction furnace 300 is connected with trichlorosilane heater 200 with hydrogen heater 100 respectively, for making through heatingProcess hydrogen and trichlorosilane in the interior generation reduction reaction of reduction furnace 300, to obtain polysilicon and reduction furnace tail gas, itsIn, reduction furnace has water-cooled assembly, and reduction furnace is carried out to water-cooled, and obtains the first hot water;

Gas-liquid heat-exchange device 400 respectively with hydrogen heater 100, trichlorosilane heater 200 and reduction furnace 300Be connected, for utilizing reduction tail gas to heating through overcooled hot water, to obtain the second hot water; And

Hot water mixing arrangement 500 is connected with gas-liquid heat-exchange device 400 with reduction furnace 300 respectively, for by the first hot water andThe second hot water mixes, to obtain reducing workshop section's hot water;

Trichlorosilane purification devices 600 comprises rectifying column, and rectifying column is connected with hot water mixing arrangement 500, will reduce workSection hot water is as the thermal source of rectifying column, returns to water for use in the purify trichlorosilane workshop section that obtains purifying; Trichlorosilane purifying dressPut 600 and be connected with hydrogen heater 100, trichlorosilane heater 200 and reduction furnace 300, to utilize pure workshop sectionReturn to water respectively to hydrogen with trichlorosilane heats and reduction furnace 300 is carried out to water-cooled.

Thus, the present invention is by designing the above-mentioned system of preparing polysilicon, can by the reduction workshop section hot water finally obtaining forIn trichlorosilane purification devices 600 as the thermal source purify trichlorosilane of rectifying column. Can significantly save thus water resource and energyConsumption. In addition, mate by adopting the above-mentioned system of preparing polysilicon can realize recycling with heat energy of water resource. SpecificallyGround, the above-mentioned system of preparing polysilicon is to be implemented and realized circulation and the heat energy coupling of water resource by following manner. First hydrogenGas heater 100, trichlorosilane heater 200, reduction furnace 300 adopt respectively the water of 130 degrees Celsius to reduce insteadAnswering heating raw materials and reduction furnace is carried out cooling, is finally 150 degrees Celsius in the interior temperature that can obtain of hot water mixing arrangement 500Reduction workshop section hot water, further the reduction workshop section hot water of 150 degrees Celsius is done for trichlorosilane purification devices 600For the thermal source purify trichlorosilane of rectifying column, and to obtain temperature be that the purification workshop section of 130 degrees Celsius returns to water, and this temperature isThe purification workshop section of 130 degrees Celsius returns to water and just in time can return to hydrogen heater 100, trichlorosilane heater 200, go backIn former stove 300. Can realize water circulation and heat energy by the system of preparing polysilicon that adopts the above embodiment of the present invention thusCoupling, significantly saves energy consumption.

As shown in Figure 3, also further comprise according to the system of preparing polysilicon of the embodiment of the present invention: gas gas heat-exchange device410, gas gas heat-exchange device 410 respectively with hydrogen heater 100, trichlorosilane heater 200, reduction furnace 300And gas-liquid heat-exchange device 400 is connected, is 110 degrees Celsius through the hydrogen of heat treated and the temperature of trichlorosilane, withJust, before obtaining being incorporated into reduction furnace 300 through the hydrogen of heat treated and trichlorosilane, adopt in advance reduction tail gas to carry out in advanceHeat is to 180 degrees Celsius. Thus the heat energy of reduction tail gas is made full use of and improves reduction reaction efficiency.

According to a particular embodiment of the invention, the above-mentioned system of preparing polysilicon further comprises: make-up water device 700 and addingHot charging puts 800, and make-up water device 700 is connected with hot water mixing arrangement 500, to add supply in reduction workshop section hot waterWater. Heater 800 is connected with hot water mixing arrangement 500, so that by the reduction workshop section hot water heating after interpolation make-up water extremelyAfter 150 degrees Celsius and as the thermal source of rectifying column. Can ensure thus can not meet purification work when the water yield of reduction workshop section hot waterIn skill when institute's water consumption, the water yield lacking to supply in reduction workshop section hot water in time.

As shown in Figure 4, according to a particular embodiment of the invention, above-mentioned make-up water device 700 further comprises: Constant pressure tank 710,Constant pressure tank 720, constant pressure pump 730 and Pressure gauge 740, wherein, Constant pressure tank 710 is connected with hot water mixing arrangement 500; FixedPress pump 730 is arranged between Constant pressure tank 710 and constant pressure tank 720; Pressure gauge 740 is connected to cut with Constant pressure tank 710 and is arranged onOne side of the delivery port of proximity thermal water mixing device 500. Can adopt thus Pressure gauge 740 to monitor constantly reduction workshop section hot waterAnd the pressure of the water between purification workshop section, and then judge that whether the water yield is not enough. Simultaneously Pressure gauge 740 with determine power pump 730 andConstant pressure tank 720 is connected, and then according to make-up water in the automatic thermotropism water mixing device 500 of Pressure gauge 740 pressure changing.Can avoid thus, because output deficiency causes the rectifying column fluctuation of trichlorosilane purification devices 600 large, affecting product quality.

Therefore, according to a particular embodiment of the invention, the above-mentioned system of preparing polysilicon can further include: cooling dressPut 900, cooling device 900 is connected with device for supplying 700 with hot water mixing arrangement 500, so that by reduction workshop section hot waterPart I is used for purify trichlorosilane as the thermal source of rectifying column, and the workshop section that simultaneously obtains purifying returns to water; And will reduce workThe Part II of section hot water carries out after cooling returning to water at least with the Part III and the purification workshop section that are selected from reduction workshop section hot waterOne of mix, be the make-up water of 130 degrees Celsius to obtain temperature.

According to a particular embodiment of the invention, when the amount of the reduction workshop section hot water that hot water mixing arrangement 500 provides has exceeded trichlorineWhen hot water amount described in hydrogen silicon purification devices 600, the system of preparing polysilicon of the above embodiment of the present invention can also be by adoptingReach the coupling of the water yield with lower array apparatus. According to a particular embodiment of the invention, cooling device 900 and hot water mixing arrangement 500,Hydrogen heater 100, trichlorosilane heater 200 and reduction furnace 300 are connected, so that by reduction workshop section hot waterPart I is used for purify trichlorosilane as the thermal source of rectifying column, and the workshop section that simultaneously obtains purifying returns to water; To reduce workshop section's heatThe Part II of water carry out cooling after be selected from the Part III of reduction workshop section hot water and purification workshop section return water one of at leastMixing, is the water of 130 degrees Celsius to obtain temperature; And by obtained temperature be 130 degrees Celsius water for pointOther to hydrogen with trichlorosilane heats and reduction furnace is carried out to water-cooled.

Thus, obtain after the water of redundance can being lowered the temperature by cooling device 900 130 degrees Celsius water againReturn to water with purification workshop section and return to hydrogen heater 100, trichlorosilane heater 200 and reduction furnace 300 for formerHeating and the reduction furnace of material are cooling. And the present invention passes through one of reduction workshop section hot water unnecessary in hot water mixing arrangement 500Fraction carry out cooling after and another part be mixed to get the water of 130 degrees Celsius, and then can save cooling energy consumption.

By adopting the system of preparing polysilicon of the above embodiment of the present invention, when the reduction in hot water mixing arrangement 500The hot water amount of workshop section and trichlorosilane purification devices 600 rectifying column institute water requirements when identical, only need to add hot charging by hydrogen in advancePut 100, trichlorosilane heater 200 and the required water of reduction furnace 300 is heated to after 130 degrees Celsius, follow-upThe heat that makes full use of reduction tail gas in cyclic process can arrive whole fresh water (FW) circulation, without extra heat, coldAmount and extra make-up water. Can significantly save thus the water yield and energy consumption.

By adopting the system of preparing polysilicon of the above embodiment of the present invention, when the reduction in hot water mixing arrangement 500When the hot water amount of workshop section is less than trichlorosilane purification devices 600 rectifying column institute water requirement, can be by device for supplying 700Pressure gauge 740 monitor force change and in the reduction workshop section hot water of thermotropism water mixing devices 500, automatically add profit after make-up waterBe heated to approximately 150 degrees Celsius with heater 800, and then avoid affecting not due to water shortage or temperatureThe product quality of trichlorosilane purification devices 600.

By adopting the system of preparing polysilicon of the above embodiment of the present invention, when the reduction in hot water mixing arrangement 500The hot water amount of workshop section when with trichlorosilane purification devices 600 rectifying column institute water requirement, can be divided into two by unnecessary hot waterPart, utilizes cooling device 900 to carry out a part wherein cooling, and then makes unnecessary hot water temperature be down to 130After degree Celsius, be again delivered in hydrogen heater 100, trichlorosilane heater 200 and reduction furnace 300.

In accordance with a further aspect of the present invention, the present invention proposes a kind of system of purify trichlorosilane, wherein trichlorosilane containsDichloro-dihydro silicon and silicon tetrachloride, as shown in Figure 5, comprise according to the system of the purify trichlorosilane of the embodiment of the present invention:

The first rectification cell 100, the first rectification cells 100 are for trichlorosilane is carried out to the first rectification process, to obtainGas and the first liquid heavy constituent after liquid, the first condensation after trichlorosilane, the first condensation, wherein, after the first condensation, liquid contains twoChlorine dihydro silicon and trichlorosilane, the first liquid heavy constituent contains silicon tetrachloride and trichlorosilane;

The second rectifier unit 200, the second rectifier units 200 are connected with the first rectification cell 100, for the first liquid state is recombinatedPoint carry out the second rectification process, to obtain gas and the second liquid heavy constituent after liquid after the second condensation, the second condensation, wherein,After the second condensation, liquid contains silicon tetrachloride;

Condensing unit 300, condensing unit 300 is connected with the second rectifier unit 200 with the first rectification cell 100, for toAfter one condensation after gas and the second condensation gas one of at least carry out condensation process, to obtain liquid and the 3rd condensation after the 3rd condensationRear gas; And

The 3rd rectifier unit 400, the three rectifier units 400 are connected with condensing unit 300 with the first rectification cell 100, forTo liquid after liquid after the first condensation and the 3rd condensation one of at least carry out the 3rd rectification process so that obtain liquid after the 4th condensation,Gas and the 3rd liquid heavy constituent after the 4th condensation, wherein, after the 4th condensation, liquid contains dichloro-dihydro silicon, the 3rd liquid heavy constituentContain trichlorosilane;

Wherein, the thermal source one of at least of the first rectification cell 100, the second rectifier unit 200, the 3rd rectifier unit 400 isReduction workshop section hot water, and reduction workshop section hot water is from the system of preparing polysilicon, as shown in Figure 2, prepares polysilicon systemComprise:

Hydrogen heater 100, trichlorosilane heater 200, reduction furnace 300, gas-liquid heat-exchange device 400, hot waterMixing arrangement 500 and trichlorosilane purification devices 600.

Wherein, described hot water mixing arrangement 500 and the first rectification cell 100, the second rectifier unit 200, the 3rd rectifier unit400 one of be at least connected.

The system of the purify trichlorosilane below with reference to Fig. 5 to the embodiment of the present invention is described in detail. According to reality of the present inventionExecute example, this system comprises:

The first rectification cell 100: according to embodiments of the invention, the first rectification cell 100 carries out first for trichlorosilaneRectification process, thus gas and the first liquid heavy constituent after liquid after trichlorosilane, the first condensation, the first condensation can be obtained respectively.According to embodiments of the invention, after the first condensation, liquid can contain dichloro-dihydro silicon and trichlorosilane, and the first liquid heavy constituent canTo contain silicon tetrachloride and trichlorosilane. According to embodiments of the invention, can adopt the rectifying column of multiple series connection to carry out firstRectification process, according to a particular embodiment of the invention, can adopt the rectifying column of five series connection to carry out the first rectification process. RootAccording to concrete example of the present invention, the rectifying column of five series connection comprises the first to the 5th rectifying column, and each includes: towerLiquid outlet at the bottom of body, tower overhead gas outlet, tower, charging aperture, condensation separator, heater, wherein, limit rectifying in tower bodySpace, is suitable for the material in rectifying space to carry out rectification process, thereby can obtain respectively liquid and tower overhead gas at the bottom of tower; Tower topGas outlet is arranged on the top of tower body, is suitable for exporting tower overhead gas; At the bottom of tower, liquid outlet is arranged on the bottom of tower body, is suitable for exporting towerEnd liquid; Charging aperture is arranged on tower body, is suitable for introducing the material for the treatment of rectifying in rectifying space; Condensation separator and tower overhead gasOutlet is connected, and is suitable for tower overhead gas to carry out condensation separation processing, thereby can obtains condensing gas and condensate liquid; Heater and towerBody is connected, and is suitable for rectifying space to heat.

Concrete, by heater, heat treated is carried out in the first rectifying column rectifying space, then by charging aperture to rectifying skyBetween in add trichlorosilane (coarse fodder that contains 85% left and right trichlorosilane), the light component that makes to contain a large amount of dichloro-dihydro silicon andThe mist of lower boiling impurity is discharged from top gas outlet, then mist is carried out to condensation through condensation separator and dividesFrom processing, thus after the first rectifying column condensation that can obtain respectively containing dichloro-dihydro silicon and trichlorosilane liquid and the first essenceHeat up in a steamer gas after tower condensation, and heavy constituent and high boiling impurity as the first rectifying tower at the bottom of liquid discharge from the outlet of furnace bottom liquid. According toEmbodiments of the invention, the first rectifying column can be high-efficiency guide sieve-plate tower, and tower internal diameter is 1500mm, and the number of plates is 76,Charging aperture is 32nd～55 blocks of column plates, and tower top operating pressure is 0.245MPaG, and operating temperature is 71～73 DEG C, tower reactor operationPressure is 0.298MPaG, and operating temperature is 77～79 DEG C, and reflux ratio is 133.5. At the bottom of the first rectifying tower, liquid is as the second essenceThe rectifying material for the treatment of that heats up in a steamer tower carries out rectification process, can remove most of silicon tetrachloride, heavy constituent impurity and high-boiling-point impurity,Thereby can obtain respectively after liquid after Second distillation column condensation, Second distillation column condensation liquid at the bottom of gas and Second distillation column tower. According toEmbodiments of the invention, Second distillation column can be high-efficiency guide sieve-plate tower, and tower internal diameter is 1500mm, and the number of plates is 76,Charging aperture is 32nd～55 blocks of column plates, and tower top operating pressure is 0.243MPaG, and operating temperature is 71～73 DEG C, tower reactor operationPressure is 0.297MPaG, and operating temperature is 84～87 DEG C, and reflux ratio is 14.5. After Second distillation column condensation, liquid is as the 3rdThe rectifying material for the treatment of of rectifying column carries out rectification process, can further remove light component impurity residual in material, makes in materialLight component impurity content reaches the requirement of electron level trichlorosilane, thereby can obtain respectively liquid, the 3rd after the 3rd rectifying column condensationLiquid at the bottom of gas and the 3rd rectifying tower after rectifying column condensation. According to embodiments of the invention, the 3rd rectifying column can be high-efficiency guideSieve-plate tower, tower internal diameter is 1500mm, and the number of plates is 76, and charging aperture is 32nd～55 blocks of column plates, and tower top operating pressure is0.25MPaG, operating temperature is 71～73 DEG C, and tower reactor operating pressure is 0.304MPaG, and operating temperature is 77～79 DEG C, returnsStream is than being 128.5. At the bottom of the 3rd rectifying tower, liquid treats that as the 4th rectifying column rectifying material carries out rectification process, can remove materialIn the heavy constituent impurity of middle remnants, thereby can obtain respectively gas after liquid after the 4th rectifying column condensation, the 4th rectifying column condensationWith liquid at the bottom of the 4th rectifying tower. According to embodiments of the invention, the 4th rectifying column can be high-efficiency guide sieve-plate tower, tower internal diameterFor 1500mm, the number of plates is 76, and charging aperture is that 32nd～55 blocks of column plates go out, and tower top operating pressure is 0.250MPaG,Operating temperature is 71～73 DEG C, and tower reactor operating pressure 0.303MPaG is, operating temperature is 77～79 DEG C, and reflux ratio is 18.After the 4th rectifying column condensation, liquid carries out rectification process as the rectifying material for the treatment of of the 5th rectifying column, can further remove in materialRemaining heavy constituent impurity, thus gas and the 5th rectifying after liquid after the 5th rectifying column condensation, the 5th rectifying column condensation can be obtainedLiquid at the bottom of tower tower. According to embodiments of the invention, the 5th rectifying column can be high-efficiency guide sieve-plate tower, and tower internal diameter is 1500mm,The number of plates is 76, and charging aperture is 32nd～55 blocks of column plates, and tower top operating pressure is 0.246MPaG, and operating temperature is71～73 DEG C, tower reactor operating pressure is 0.298MPaG, and operating temperature is 77～79 DEG C, and reflux ratio is 20.

The second rectifier unit 200: according to embodiments of the invention, the second rectifier unit 200 is connected with the first rectification cell,For the liquid heavy constituent of above gained first is carried out to the second rectification process, thereby can obtain liquid after the second condensation, second coldGas and the second liquid heavy constituent after solidifying. According to embodiments of the invention, after the second condensation, in liquid, contain silicon tetrachloride. According to thisThe specific embodiment of invention, can carry out the second rectification process by liquid at the bottom of the first to the 5th rectifying column tower one of at least, for example,Liquid at the bottom of Second distillation column tower can be carried out to the second rectification process as the first liquid heavy constituent. According to embodiments of the invention,The second liquid restructuring is divided into waste liquid, can directly be delivered to liquid waste processing operation and process. Inventor finds, the second essenceHeat up in a steamer and in liquid, contain silicon tetrachloride and a large amount of heavy constituent impurity at the bottom of tower tower, can effectively remove greatly by carrying out the second rectification processThe heavy constituent impurity of part, thus finished product silicon tetrachloride can be obtained. Particularly, the second rectifier unit can be high-efficiency guideSieve-plate tower, tower internal diameter is 2200mm, and the number of plates is 60, and charging aperture is 25th～45 blocks of column plates, and tower top operating pressure is0.213MPaG, operating temperature is 89～92 DEG C, and tower reactor operating pressure is 0.223MPaG, and operating temperature is 128～131 DEG C,Reflux ratio is 4.5.

Condensing unit 300: according to embodiments of the invention, condensing unit 300 and the first rectification cell 100 and the second rectifyingDevice 200 is connected, for to gas after gas and the second condensation after above gained the first condensation one of at least carry out condensation process,Thereby can obtain after the 3rd condensation gas after liquid and the 3rd condensation. According to embodiments of the invention, the condition of condensation process is notBe particularly limited, according to a particular embodiment of the invention, condensation process can be-40～-38 degrees Celsius in temperature and with pressure beUnder the condition of 0.1～0.15MPaG, carry out. Inventor's discovery, the condensation process of carrying out under this condition can obviously improve after condensationThe separative efficiency of liquid after gas and condensation. According to embodiments of the invention, can one of at least producing the first to the 5th rectifying columnAfter raw condensation gas as the first condensation after gas carry out condensation process. Inventor finds, after the first condensation after gas and the second condensationIn gas, contain a large amount of dichloro-dihydro silicon and a small amount of trichlorosilane, carried out carrying out again subsequent treatment after condensation process, canTo significantly improve the utilization rate of material, can reduce exhaust emissions amount simultaneously. According to embodiments of the invention, after the 3rd condensationIn gas, contain on-condensible gas, can directly be sent to exhaust-gas treatment operation and process. According to a particular embodiment of the invention, coldSolidifying device can be double tubesheet tubular heat exchanger, and heat exchanger tube pass fluid is gas after each tower condensation, shell-side fluid be-38 DEG C coldFreeze salt solution, have a pass partition in upper cover, dividing plate one side has gas inlet port after each tower condensation, and opposite side has on-condensible gasFloss hole, low head has a condensate discharge mouth.

The 3rd rectifier unit 400: according to embodiments of the invention, the 3rd rectifier unit and the first rectification cell 100 and condensationDevice 300 is connected, for to liquid after liquid after the first condensation and the 3rd condensation one of at least carry out the 3rd rectification process, therebyCan obtain gas and the 3rd liquid heavy constituent after liquid after the 4th condensation, the 4th condensation. According to a particular embodiment of the invention,After four condensations, in liquid, contain dichloro-dihydro silicon, the 3rd liquid heavy constituent contains trichlorosilane. According to embodiments of the invention, canAfter using liquid after the condensation that the first to the 5th rectifying column one of is at least produced as the first condensation, liquid carries out the 3rd rectification process. ExampleAs, can by first and the 3rd after the condensation that produces of rectifying column after liquid and the 3rd condensation liquid carry out the 3rd rectification process. InventorFind, in the first and the 3rd liquid after rectifying column condensation, contain more than 99% trichlorosilane, the dichloro-dihydro silicon less than 1% andA large amount of light component impurity (as the compound of boron), can remove the most of dichloro in light component material by the 3rd rectification processDihydro silicon and low boiling impurity, and can reach through trichlorosilane content in the 3rd rectification process gained the 3rd liquid heavy constituentTo more than 99.99%. According to embodiments of the invention, the 3rd rectifier unit can be high-efficiency guide sieve-plate tower, and tower internal diameter is1200mm, the number of plates is 76, and charging aperture is 32nd～55 blocks of column plates, and tower top operating pressure is 0.248MPaG, operationTemperature is 55～58 DEG C, and tower reactor operating pressure is 0.298MPaG, and operating temperature is 77～79 DEG C, and reflux ratio is 47.

Can prepare the required trichlorosilane of electronic-grade polycrystalline silicon according to the system of the purify trichlorosilane of the embodiment of the present invention,And by gas centralized recovery after gas and the second condensation after the condensation that the first to the 5th rectifying column is produced, and by gas collection after condensationIn carry out condensation process, can obviously reduce the consumption of cold and the discharge of tail gas, simultaneously by the bottom of Second distillation column tower liquid continueCarry out rectification process, can obtain silicon tetrachloride product, in addition, the condensation that the first to the 5th rectifying column one of is at least producedAfter rear liquid and the 3rd condensation, liquid is proceeded rectification process, can effectively trichlorosilane wherein and dichloro-dihydro silicon be dividedFrom.

According to a particular embodiment of the invention, above-mentioned the first rectification cell, the second rectifier unit, the 3rd rectifier unit are at leastOne of be connected with the hot water mixing arrangement 500 in the system of preparing polysilicon of above-described embodiment, utilize thus reduction workshop section heatWater heats the first rectification cell, the second rectifier unit, the 3rd rectifier unit, the cold water of simultaneously discharging and hydrogen heatingDevice 100 and the hot water inlet 130 of trichlorosilane heater 200 and 230 and cooling water inlet 340 phases of water-cooled assemblyConnect.

Embodiment

With reference to figure 6-7, high temperature after each rectifying tower system heat exchange water inlet (24) enters respectively each with 0.6MPaG, 130 DEG CChassis of reducing furnace is cooling, chuck is cooling, tail gas is cooling, the cooling water inlet in chassis (6) through with chassis of reducing furnace heat exchange after heatedTo 150 DEG C, the cooling water inlet of chuck (4) through with the heat exchange of reduction furnace bell jar after be heated to 150 DEG C, the cooling water inlet of tail gas (1)Carry out heat exchange, three with reduction furnace feeding trichlorosilane liquid (9) heater (E1), hydrogen gas (8) heater (E2)Chlorine hydrogen silicon, hydrogen are vaporized through 130 DEG C of hot water heatings, mix by a certain percentage, form 110 DEG C of mists (10),Mist (10) enters reduction furnace mist preheater (E3), with 580 DEG C of-610 DEG C of reduction furnace tail gas (12) heat exchangeBe that the gaseous mixture (11) of 180 DEG C enters and in reduction furnace, carries out polysilicon deposition; Through mist heater (E3) heat exchangeRear reduction tail gas (13), then it is cooling with the tail gas of trichlorosilane, hydrogen heater outlet to enter reduction exhaust gas cooler (E4)Water (2) carries out heat exchange, by 100 DEG C of-110 DEG C of reduction furnace tail gas of heat exchange (14) to device for recovering tail gas;

(3) 140 DEG C-145 DEG C, tail gas cooling water backwater and chuck cooling backwater (5), chassis cooling water backwater (7) are mixed intoEnter reduction furnace high-temperature tempering house steward (25), boost to 1.0MPaG with pump (P2) and be sent to steam heater (E5), then enterThe heat exchange of each rectifying column reboiler, reduction furnace high-temperature tempering (22) and the heat exchange to 130 DEG C of each rectifying column reboiler, through circulationWater cooler (E6) rear (23) returns to each reduction furnace and carries out cooling heat transferring, recycles.

High-temperature water system adopts closed type, for making high-temperature water system pressure and stability of flow, and reduction furnace high-temperature water pipeline (23)And between constant pressure pump (P1), increased a Constant pressure tank, on the pipeline being connected with reduction furnace high-temperature water, (17) increase simultaneouslyPressure gauge, Pressure gauge will directly show jacket water (J.W.) system pressure, when system pressure is when arranging minimum pressure 0.97MPaG,Pressure gauge is by given signal transmission water pump (P1), and level pressure water pump (P1) is started working, by (14) to high-temperature tempering pipeRoad (15) carries out supercharging; When system pressure is greater than when maximum pressure 1.05MPAG is set, Pressure gauge is given by signal transmissionWater pump (P1), level pressure water pump (P1) quits work. After level pressure water pump (P1) quits work, high-temperature water system pressureCompensate by Constant pressure tank, in the time of high-temperature water system pressure drop, the gas in Constant pressure tank is wanted naturally to expand, and interior water is at gasUnder pressure, automatically fill into high-temperature tempering pipeline (15) through (14); When the water in Constant pressure tank is reduced to a certain degree, by level pressureWater pump is realized supercharging, and the gas in tank is again compressed. Work and so forth, high-temperature water system carries out voltage stabilizing and moisturizing.

Reduction furnace high-temperature tempering is as the direct heat source of rectifying tower system reboiler, and reduction furnace start-stop can be to essence in process of productionHeating up in a steamer Tower System temperature, flow causes fluctuation and the system system hot water temperature that drives for the first time not reach rectifying column reboiler temperature, streamAmount increased a steam heater (E5), steam before reduction furnace high-temperature tempering (20) enters rectifying tower system reboiler(28) by reduction steam heater (E5), reduction furnace high-temperature tempering (20) is heated to 150 DEG C with 1.2MPaG, 190 DEG C,Reduction steam heater (E5) bottom steam condensed water (29) is got back to boiler, high-temperature tempering house steward (23) and reduction high temperatureSupply mains into and out of bypass (15) regulate, make to enter rectifying tower system high-temperature water (21) temperature and stability of flow 150 DEG C,1700m³/ h, has ensured that rectifying column technological parameter is stable; Rectifying tower system part is stopped tower to operation reduction furnace in process of productionHigh temperature water inlet (23) temperature, flow can cause fluctuation, enter (17), return main (22) increase by rectifying column reboilerCover recirculated water plate type heat exchanger (E6), recirculated water enters (26), recirculated water water outlet (27) by recirculated water plate type heat exchanger (E6)High-temperature cooling water (19) is carried out cooling, enter steam heater (E5) reduction furnace high temperature water inlet manifold (17) bypass (18)To rectifying tower system water plate type heat exchanger reboiler backwater (22) afterwards, rely on bypass (18) to regulate, ensure to enter reductionFurnace system High-temperature cooling water inlet (23) temperature, stability of flow are at 130 DEG C, 2100m³/h。

5000 tons/year of polycrystalline silicon production lines, reduction direct consumption of electr ic energy 70kw.h/kgsi, product 625kg silicon per hour, chuck, chassis,Tail gas cooling water is taken away approximately 80% heat, the heat of reduction furnace chuck, chassis, the recovery per hour of tail gas cooling water:35000KW. Reduction furnace chuck, chassis, tail gas cooling water by 130 DEG C of water inlets, 150 DEG C of water outlets, 20 DEG C of calculating of the temperature difference,The total Water needing: 35000*860.6/20=1506m³/h；

Distillation system amounts to 13 towers, and 6, synthesis material rectifying column, reverts back 6, rewinding rectifying column, silicon tetrachloride rectifying column1, the each tower reboiler of synthesis material rectifying column institute heat consumption is 1870KW, the heat dissipation water 78m of institute³/ h, reverts back rewinding essenceHeating up in a steamer the each tower reboiler of tower institute heat consumption is 3920KW, the heat dissipation water 164m of institute³/ h, silicon tetrachloride rectifying column reboiler consumesHeat is 3950KW, the heat dissipation water 165m of institute³/ h; It is 38690KW that rectifying tower system amounts to institute's heat consumption, institute's heat dissipation water1617m³/h；

After reduction furnace chuck, chassis, the comprehensive utilization of tail gas cooled water heat energy, whole distillation system only need to supplement 5.2t/h and steamVapour can meet, and reduction furnace high-temperature water does not need circulating water, and distillation system does not need Steam Heating, can be system of rectifying towerThe minimizing heat 35000KW per hour that unites, amounts to steam 50t/h, and steam is by 140 yuan/ton of calculating, per hourly can save 7000Unit, can save 5,040 ten thousand yuan the whole year. Reduction chuck, chassis, tail gas cooling water are pressed circulating water, 5 DEG C of temperature difference of recirculated water,Quantity of circulating water is exactly 35000X861.24 ÷ 5 ÷ 1000=6028m so³/ h, a water circulating pump flow is 5000m³/h，A water circulating pump power is 1000kw.h, and separate unit power of fan is 180kw.h, calculates: per hour by 0.5 yuan/kw.h590 yuan can be saved, 424.8 ten thousand yuan can be saved the whole year; Circulation year is saved moisturizing 100000m³, every Fang Shui is by 5Unit is calculated, 500,000 yuan of year saving.

Three add up to save the whole year: ten thousand yuan of 5040+424.8+50=5514.8

The technology transformation can make distillation system reduce by 91% steam consumption, makes device for recovering tail gas reduce refrigerator load5%, reduction power consumption reduces by 10%, and full factory recirculated water consumption reduces approximately 33.4%.

In the description of this description, reference term " embodiment ", " some embodiment ", " example ", " concrete example ",Or the description of " some examples " etc. means specific features, structure, material or the feature bag described in conjunction with this embodiment or exampleBe contained at least one embodiment of the present invention or example. In this manual, needn't pin to the schematic statement of above-mentioned termRight is identical embodiment or example. And specific features, structure, material or the feature of description can be at anyOr in multiple embodiment or example with suitable mode combination. In addition, not conflicting in the situation that, the technology of this areaPersonnel the feature of the different embodiment that describe in this description or example and different embodiment or example can be carried out combination andCombination.

Although illustrated and described embodiments of the invention above, be understandable that, above-described embodiment is exemplary,Can not be interpreted as limitation of the present invention, those of ordinary skill in the art within the scope of the invention can be to above-described embodimentChange, amendment, replacement and modification.

Claims

1. a method of preparing polysilicon, is characterized in that, comprising:

(2) hydrogen and the trichlorosilane of the described process heat treated obtaining in step (1) are reduced in reduction furnaceReaction, to obtain polysilicon and reduction tail gas, wherein, in reduction reaction process, carries out water-cooled to described reduction furnace,And obtain the first hot water;

Wherein, the temperature of described the first hot water and described the second hot water respectively independently within the scope of 145～155 degrees Celsius,

The hot water temperature who adopts in step (1) is 130 degrees Celsius, adopts the water of 130 degrees Celsius in step (2)Chassis to described reduction furnace and chuck carry out described water-cooled respectively.

2. method according to claim 1, is characterized in that, the described hydrogen through heat treated and trichlorosilaneTemperature is 110 degrees Celsius, and described hydrogen and the trichlorosilane through heat treated obtaining in step (1) drawnEnter to before described reduction furnace, adopt in advance described reduction tail gas to be preheated to 180 degrees Celsius.

3. method according to claim 1, is characterized in that, in step (4), comprising:

4. method according to claim 3, is characterized in that, described make-up water obtains through the following steps:

5. method according to claim 1, is characterized in that, in step (4), further comprises

6. a method for purify trichlorosilane, contains dichloro-dihydro silicon and tetrachloro hydrogen silicon in described trichlorosilane, its feature existsIn, described method comprises:

(1) described trichlorosilane is carried out to the first rectification process, to obtain liquid after trichlorosilane, the first condensation, first coldGas and the first liquid heavy constituent after solidifying, wherein, after described the first condensation, liquid contains dichloro-dihydro silicon and trichlorosilane, and described theOne liquid heavy constituent contains tetrachloro hydrogen silicon and trichlorosilane;

(2) described the first liquid heavy constituent is carried out to the second rectification process, to obtain after liquid after the second condensation, the second condensationGas and the second liquid heavy constituent, wherein, after described the second condensation, liquid contains silicon tetrachloride;

(4) by liquid after liquid after described the first condensation and described the 3rd condensation one of at least carry out the 3rd rectification process, to obtainGas and the 3rd liquid heavy constituent after liquid, the 4th condensation after the 4th condensation, wherein, after described the 4th condensation, liquid contains dichloro twoHydrogen silicon, described the 3rd liquid heavy constituent contains trichlorosilane

(1) utilize hot water respectively hydrogen and trichlorosilane to be heated, to obtain hot water and warp through overcooled hot waterCross hydrogen and the trichlorosilane of heat treated,

(4) described the first hot water and described the second hot water are mixed, to obtain described reduction workshop section hot water, wherein, described inThe temperature of the first hot water and described the second hot water is respectively independently in the scope of 145～155 degrees Celsius.

7. a system of preparing polysilicon, is characterized in that, comprising:

Hydrogen heater and trichlorosilane heater, described hydrogen heater and trichlorosilane heater utilize hot waterRespectively hydrogen and trichlorosilane are heated, to obtain hydrogen and the trichlorine through overcooled hot water and process heat treatedHydrogen silicon;

Reduction furnace, described reduction furnace is connected with trichlorosilane heater with described hydrogen heater respectively, described in makingIn reduction furnace, there is reduction reaction in hydrogen and trichlorosilane through heat treated, to obtain polysilicon and reduction furnace tail gas,Wherein, described reduction furnace has water-cooled assembly, and described reduction furnace is carried out to water-cooled, and obtains the first hot water;

8. the system of preparing polysilicon according to claim 7, is characterized in that, further comprises:

Gas gas heat-exchange device, described gas gas heat-exchange device respectively with described hydrogen heater, trichlorosilane heater,Reduction furnace and gas-liquid heat-exchange device are connected, and described is 110 Celsius through the hydrogen of heat treated and the temperature of trichlorosilaneDegree, to obtain before described hydrogen through heat treated and trichlorosilane be incorporated into described reduction furnace, described in adopting in advanceReduction tail gas is preheated to 180 degrees Celsius.

9. the system of preparing polysilicon according to claim 8, is characterized in that, further comprises:

Make-up water device, described make-up water device is connected with described hot water mixing arrangement, so that in described reduction workshop section hot waterAdd make-up water;

10. the system of preparing polysilicon according to claim 9, is characterized in that, further comprises:

11. systems of preparing polysilicon according to claim 10, is characterized in that, described cooling device and described heatWater mixing device, hydrogen heater, trichlorosilane heater and reduction furnace are connected, so that by described reduction workshop section heatThe Part I of water is used for purify trichlorosilane as the thermal source of rectifying column, and the workshop section that simultaneously obtains purifying returns to water; Go back describedThe Part II of former workshop section hot water carry out cooling after with the Part III and the described purification workshop section that are selected from described reduction workshop section hot waterReturning to one of at least mixing of water, is the water of 130 degrees Celsius to obtain temperature; And be 130 by obtained temperatureDegree Celsius water for respectively to described hydrogen with trichlorosilane heats and described reduction furnace is carried out to water-cooled.

12. systems of preparing polysilicon according to claim 9, is characterized in that, described make-up water device is furtherComprise:

Constant pressure tank;

Pressure gauge, described Pressure gauge be connected with described Constant pressure tank and be arranged on contiguous described hot water mixing arrangement delivery port oneSide.

The system of 13. 1 kinds of purify trichlorosilanes, described trichlorosilane contains dichloro-dihydro silicon and silicon tetrachloride, and its feature existsIn, described system comprises:

The 3rd rectifier unit, described the 3rd rectifier unit is connected with described condensing unit with described the first rectification cell, for rightAfter described the first condensation after liquid and described the 3rd condensation liquid one of at least carry out the 3rd rectification process, to obtain the 4th condensationGas and the 3rd liquid heavy constituent after rear liquid, the 4th condensation, wherein, after described the 4th condensation, liquid contains dichloro-dihydro silicon, described inThe 3rd liquid heavy constituent contains trichlorosilane,