阅读说明：本技术 一种螺旋输送两效蒸发煤料调湿装置及在线控制湿度的方法 (Spiral conveying dual-effect evaporation coal material humidity adjusting device and online humidity control method ) 是由 陈宗凯 王跃 马志良 于 2021-08-06 设计创作，主要内容包括：本发明涉及一种螺旋输送两效蒸发煤料调湿装置及在线控制湿度的方法,属于煤料水分控制技术领域。技术方案是：高温蒸汽对第二段螺旋输送机内的煤料进行间接加热,被加热的煤料产生的低温蒸汽通过进入第一段螺旋输送机的外套管,对第一段螺旋输送机输送的煤料进行预热,形成两效蒸发；通过实时在线监测由煤料蒸发产生的水分计量信息,反馈给PID控制系统,通过与设定的参数相比较,得出差异,进行煤料湿度的在线精准控制。本发明的有益效果：实现煤料精准的湿度控制,采用两效蒸发提高能源热传导利用率,节能降耗,封闭的环境中完成对煤料的实时在线精准调湿,不产生扬尘,利于环保。(The invention relates to a spiral conveying double-effect evaporation coal material humidity adjusting device and an online humidity control method, and belongs to the technical field of coal material moisture control. The technical scheme is as follows: the high-temperature steam indirectly heats the coal material in the second section of screw conveyor, and the low-temperature steam generated by the heated coal material enters the outer sleeve of the first section of screw conveyor to preheat the coal material conveyed by the first section of screw conveyor to form double-effect evaporation; the moisture metering information generated by coal evaporation is monitored in real time on line, the moisture metering information is fed back to a PID control system, and the moisture metering information is compared with set parameters to obtain the difference so as to perform on-line accurate control on the humidity of the coal. The invention has the beneficial effects that: the method has the advantages of realizing accurate humidity control of the coal material, improving the heat conduction utilization rate of energy by adopting two-effect evaporation, saving energy, reducing consumption, completing real-time online accurate humidity control of the coal material in a closed environment, not generating raise dust and being beneficial to environmental protection.)

1. The utility model provides a spiral delivery dual-effect evaporation coal material humidifying device which characterized in that: a first section of screw conveyor (2) and a second section of screw conveyor (4) which are connected end to end form a double-effect evaporation system, high-temperature steam indirectly heats coal materials in the second section of screw conveyor, and low-temperature steam generated by the heated coal materials preheats the coal materials conveyed by the first section of screw conveyor through an outer sleeve pipe entering the first section of screw conveyor, so that double-effect evaporation is formed.

2. The spiral conveying two-effect evaporation coal material humidity adjusting device as claimed in claim 1, characterized in that: a hollow shaft (7) is arranged in a second core pipe (22) of the second section of screw conveyor (4), a second helical blade (13) is arranged on the hollow shaft (7), a steam inlet rotary joint (14) and a steam outlet rotary joint (16) are respectively arranged at two ends of the hollow shaft (7), high-temperature steam is introduced into the hollow shaft (7), the high-temperature steam enters and exits the hollow shaft (7) through the steam inlet rotary joint (14) and the steam outlet rotary joint (16), and the heat conduction area is increased by the second helical blade which rotates.

3. The spiral conveying dual-effect evaporation coal moisture control device as claimed in claim 1 or 2, wherein: and a second core pipe (22) of the second section of screw conveyor (4) is communicated with an outer sleeve (17) of the first section of screw conveyor (2) through a low-temperature steam conduit (3), and low-temperature steam generated by the heated coal enters the outer sleeve of the first section of screw conveyor through the low-temperature steam conduit (3).

4. The spiral conveying dual-effect evaporation coal moisture control device as claimed in claim 1 or 2, wherein: an outer sleeve (17) is arranged outside a first core pipe (21) of the first section of the screw conveyor (2); a water vapor outlet (23) is formed in the outer sleeve (17), a metering device (9) is arranged on the water vapor outlet (23), the volume or the mass of the discharged water vapor is metered through the metering device (9) and is used as a coal moisture evaporation parameter, the difference is obtained by comparing the water vapor with the set parameter, the amount of high-temperature steam introduced into the second section of spiral conveyor (4) is adjusted, and the accurate control of the coal moisture is realized; the water vapor outlet (23) is provided with a pump (10) to form micro negative pressure, so that the evaporation of the water in the coal material is accelerated, and the formation of dust is avoided.

5. The spiral conveying dual-effect evaporation coal moisture control device as claimed in claim 1 or 2, wherein: the discharge hole of the first section of screw conveyor (2) is connected with the feed hole of the second section of screw conveyor (4) through a feeding chute (11); the feed inlet of the first section of screw conveyor (2) is provided with a star-shaped feeder (1), and the second section of screw conveyor (4) is provided with a coal outlet (15).

6. The spiral conveying two-effect evaporation coal material humidity adjusting device as claimed in claim 2, characterized in that: high-temperature steam is introduced into the hollow shaft (7) to indirectly heat the coal material in the second section of the screw conveyor (4); a steam sleeve (12) is arranged outside a second core pipe (22) of the second-stage screw conveyor (4), high-temperature steam is introduced into the steam sleeve (12), and meanwhile, coal in the second core pipe (22) of the second-stage screw conveyor (4) is heated and dried.

7. The spiral conveying two-effect evaporation coal material humidity adjusting device as claimed in claim 2, characterized in that: and a heat-insulating layer (19) is arranged outside a second core pipe (22) of the second section of screw conveyor (4), and high-temperature steam introduced into the hollow shaft (7) indirectly heats the coal in the second section of screw conveyor (4).

8. A method for controlling humidity of coal material on line by using the humidity control device defined in any one of claims 1 to 8, comprising the steps of:

and monitoring the moisture metering information generated by the evaporation of the coal material on line in real time, feeding the moisture metering information back to the PID control system, comparing the moisture metering information with the set parameters to obtain the difference, and performing on-line accurate control on the humidity of the coal material.

9. The method for controlling the humidity of the coal material on line according to claim 8, wherein the method comprises the following steps: the on-line accurate control of the coal moisture at least comprises the following three adjusting modes:

firstly, the total amount of high-temperature steam entering a second section of screw conveyor (4) is kept unchanged, and the change of the coal material flow entering a first section of screw conveyor (2) is realized by adjusting the frequency of a star-shaped feeder motor, so that the accurate control of coal material humidifying is realized;

secondly, keeping the coal material flow entering the first section of screw conveyor (2) unchanged, and realizing accurate control of coal material humidifying by adjusting the flow of high-temperature steam entering the second section of screw conveyor;

and thirdly, the frequency of the star-shaped feeder motor and the flow of high-temperature steam entering the second section of screw conveyor are simultaneously adjusted, so that the accurate control of coal moisture control is realized.

10. The method for controlling the humidity of the coal material on line according to the claim 8 or 9, characterized in that: the coal material gets into first section screw conveyer (2) and second section screw conveyer (4) in proper order, and the high-temperature steam that lets in carries out indirect heating to the coal material in second section screw conveyer (4), and the low-temperature steam that the coal material that is heated produced gets into outer tube (17) of first section screw conveyer (2) through low-temperature steam pipe (3), preheats the coal material that first section screw conveyer carried, forms two effect evaporation.

Technical Field

The invention relates to a spiral conveying double-effect evaporation coal material humidity adjusting device and an online humidity control method, and belongs to the technical field of coal material moisture control.

Background

The coal moisture control technology is a short term for a charging coal moisture control process, namely, a part of moisture of coking coal is removed before charging, the moisture of the charging coal is kept to be controlled at about 6%, and then the charging is carried out for coking production. Different from coal preheating and coal drying, the method has strict moisture control measures and can ensure constant moisture of the coke oven coal. The technology directly or indirectly heats to reduce and stably control the moisture contained in the coal as fired. The modern coking mainly adopts wet coal for coking, and the coking coal charged into the coke oven has high moisture and needs drying and humidity adjustment. The basic principle of coal drying and coal humidifying is that coal materials are dried and dehydrated outside a coke oven by using external heat energy to reduce the moisture of coal as fired or regulate the moisture of the coal as fired, so as to control the coking energy consumption, improve the operation of the coke oven, improve the coke quality or enlarge the using amount of caking coal, the moisture of coal as fired is stable, the operation of the coke oven is stable, the coke is prevented from being immature or overfire, the moisture of the coal as fired is generally required to be kept at about 6%, and how to perform online drying and humidifying is a technical problem to be solved urgently in the field. The prior art mainly comprises the following drying modes: the first generation is a heat conduction oil drying mode; the waste heat of the flue gas and the sensible heat of the ascending pipe of the coke oven are recovered by utilizing heat conduction oil, and then the heat conduction oil indirectly heats the coal material in a multi-pipe rotary dryer, thereby realizing the drying of the coal material. The second generation is a steam drying mode; in the method, backpressure steam generated after dry quenching steam power generation or other low-pressure steam in a factory is used as a heat source, and the steam is used for indirectly heating and drying the coal material in a multi-tube dryer. The third generation adopts a vulcanizing bed device; the coke oven coal flue waste gas and coke oven gas are used for heating the coke oven coal flue waste gas and the coke oven gas. The prior art has the following problems: the moisture and humidity of the coal cannot be accurately controlled, the drying process of the coal is unreasonable, the heat conduction utilization rate of energy is low, the humidifying of the coal cannot be completed in a closed environment, dust is easy to raise, and the environment friendliness is not facilitated.

Disclosure of Invention

The invention aims to provide a spiral conveying dual-effect evaporation coal material humidity regulating device and an online humidity controlling method, which are used for realizing accurate humidity control of coal materials, improving the heat conduction utilization rate of energy by adopting dual-effect evaporation, saving energy, reducing consumption, completing real-time online accurate humidity regulation of the coal materials in a closed environment, avoiding dust emission, being beneficial to environmental protection and solving the problems in the background technology.

The technical scheme of the invention is as follows:

the utility model provides a spiral delivery dual-effect evaporation coal material humidifying device, is become dual-effect evaporation system by end to end's first section screw conveyer and second section screw conveyer, and high temperature steam carries out indirect heating to the coal material in the second section screw conveyer, and the low temperature steam that the coal material that is heated produced preheats the coal material that first section screw conveyer carried through the outer tube that gets into first section screw conveyer, forms dual-effect evaporation.

The second section of screw conveyor is characterized in that a hollow shaft is arranged in a core pipe II of the second section of screw conveyor, a screw blade II is arranged on the hollow shaft, a steam inlet rotary joint and a steam outlet rotary joint are respectively arranged at two ends of the hollow shaft, high-temperature steam is introduced into the hollow shaft, the high-temperature steam enters and exits the hollow shaft through the steam inlet rotary joint and the steam outlet rotary joint, and the heat conduction area is increased by the rotary screw blade II.

And the second core pipe of the second section of screw conveyor is communicated with the outer sleeve of the first section of screw conveyor through a low-temperature steam conduit, and low-temperature steam generated by the heated coal enters the outer sleeve of the first section of screw conveyor through the low-temperature steam conduit. The low-temperature steam guide pipe is cleaned by air compression or high-pressure steam in a pulse mode, and the coal fine particles are prevented from being deposited and blocking a pipeline.

An outer sleeve is arranged outside the first core tube of the first section of the screw conveyor; the outer sleeve is provided with a water vapor outlet, the water vapor outlet is provided with a metering device, the volume or the mass of the discharged water vapor is metered by the metering device to be used as a coal moisture evaporation parameter, the difference is obtained by comparing the water vapor evaporation parameter with the set parameter, the amount of high-temperature steam introduced into the second section of screw conveyor is adjusted, and the accurate control of the coal moisture is realized; the steam outlet is provided with a pump to form micro negative pressure, so that the evaporation of the water in the coal material is accelerated, and the formation of dust is avoided.

The discharge hole of the first section of screw conveyor is connected with the feed hole of the second section of screw conveyor through a discharging chute; the feed inlet of the first section of screw conveyor is provided with a star-shaped feeder, and the second section of screw conveyor is provided with a coal outlet.

A solid shaft is arranged in a core pipe I of the first section of the screw conveyor, and a screw blade I is arranged on the solid shaft.

The second section of the screw conveyor has two structures:

the structure I is as follows: in the first embodiment, high-temperature steam is introduced into the hollow shaft to indirectly heat the coal material in the second section of screw conveyor. And a steam sleeve is arranged outside the core pipe of the second-stage screw conveyor, high-temperature steam is introduced into the steam sleeve, and coal in the core pipe II of the second-stage screw conveyor is heated and dried.

The structure II is as follows: and in the second embodiment, a heat-insulating layer is arranged outside the core pipe of the second section of screw conveyor, and high-temperature steam introduced into the hollow shaft indirectly heats the coal in the second section of screw conveyor.

A method for controlling humidity of coal materials on line adopts the control system, and comprises the following steps:

and monitoring the moisture metering information generated by the evaporation of the coal material on line in real time, feeding the moisture metering information back to the PID control system, comparing the moisture metering information with the set parameters to obtain the difference, and performing on-line accurate control on the humidity of the coal material.

And the moisture metering information generated by the coal evaporation at least comprises the volume or the mass of the water vapor generated by the coal evaporation.

The on-line accurate control of the coal moisture at least comprises the following three adjusting modes:

1. the total amount of high-temperature steam entering the second section of screw conveyor is kept unchanged, and the change of the coal material flow entering the first section of screw conveyor is realized by adjusting the frequency of a star-shaped feeder motor, so that the accurate control of coal material humidifying is realized;

2. keeping the coal material flow entering the first section of screw conveyor unchanged, and realizing accurate control of coal material moisture control by adjusting the flow of high-temperature steam entering the second section of screw conveyor;

3. and meanwhile, the frequency of the star-shaped feeder motor and the flow of high-temperature steam entering the second section of screw conveyor are adjusted, so that the accurate control of coal moisture control is realized.

The coal material sequentially enters the first section of screw conveyor and the second section of screw conveyor, the introduced high-temperature steam indirectly heats the coal material in the second section of screw conveyor, the low-temperature steam generated by the heated coal material enters the outer sleeve of the first section of screw conveyor through the low-temperature steam guide pipe, and the coal material conveyed by the first section of screw conveyor is preheated to form double-effect evaporation.

The water vapor outlet on the outer sleeve of the first section of screw conveyor is provided with a metering device, the volume or the mass of the discharged water vapor is metered by the metering device and is used as a water evaporation parameter of the coal material, and the difference is obtained by comparing the parameters with the set parameters, so that the on-line accurate control of the humidity of the coal material is carried out.

The steam outlet is provided with a pump to form micro negative pressure, so that the evaporation of the water in the coal material is accelerated, and the formation of dust is avoided. And a low-temperature steam guide pipe between the first section of screw conveyor and the second section of screw conveyor is cleaned by air compression or high-pressure steam in a pulse mode, so that the deposition of fine particles of coal materials is prevented, and pipelines are prevented from being blocked. The first spiral blade and the second spiral blade of the first section of spiral conveyer and the second section of spiral conveyer increase the heat conduction area through rotation.

The high-temperature steam in the second section of screw conveyor is subjected to steam supply amount adjustment through an adjusting valve, and the adjusting valve adjusts the high-temperature steam supply amount of the hollow shaft; if high-temperature steam is introduced through the two steam sleeves of the core pipe of the second section of screw conveyor, the regulating valve can regulate the steam supply amount of the high-temperature steam of the steam sleeves.

The invention has the main innovation points that: 1. based on moisture generated by coal evaporation, the moisture is used as a control point for humidifying the coal, and the steam supply amount of high-temperature steam is controlled by a PID control system, so that the accurate control of the humidity of the coal is realized; 2. through the two-effect evaporation system that first section screw conveyer and second section screw conveyer of innovation structure are constituteed, the screw feed coal charge, inside and outside two double-effect evaporation structure of double-layered cover, make full use of steam energy both can measure the coal charge evaporation on line and produce moisture, realize the dry humidifying to the coal charge again.

The invention has the beneficial effects that: the method has the advantages of realizing accurate humidity control of the coal material, improving the heat conduction utilization rate of energy by adopting two-effect evaporation, saving energy, reducing consumption, completing real-time online accurate humidity control of the coal material in a closed environment, not generating raise dust and being beneficial to environmental protection.

Drawings

FIG. 1 is a schematic diagram of the system architecture of the present invention;

FIG. 2 is a schematic view of the interior of a second screw conveyor according to an embodiment of the invention;

FIG. 3 is a schematic view of the interior of a second screw conveyor according to a second embodiment of the invention;

FIG. 4 is a schematic view of the interior of the first stage screw conveyor of the present invention;

FIG. 5 is a schematic flow diagram of the system of the present invention;

in the figure: the device comprises a star-shaped feeder 1, a first-stage screw conveyor 2, a low-temperature steam guide pipe 3, a second-stage screw conveyor 4, a high-temperature steam inlet pipe 5, a steam metering adjusting device 6, a hollow shaft 7, a steam outlet 8, a metering device 9, a pump 10, a discharging chute 11, a steam sleeve 12, a second spiral blade 13, a steam inlet rotary joint 14, a coal outlet 15, a steam outlet rotary joint 16, an outer sleeve 17, a solid shaft 18, a heat insulation layer 19, a first spiral blade 20, a first core pipe 21, a second core pipe 22 and a water vapor outlet 23.

Detailed Description

The invention is further illustrated by the following examples in conjunction with the accompanying drawings.

The utility model provides a spiral delivery dual-effect evaporation coal material humidifying device, constitutes dual-effect evaporation system by end to end's first section screw conveyer 2 and second section screw conveyer 4, and high temperature steam carries out indirect heating to the coal material in the second section screw conveyer, and the low temperature steam that the coal material that is heated produced preheats the coal material that first section screw conveyer carried through the outer tube that gets into first section screw conveyer, forms dual-effect evaporation.

A hollow shaft 7 is arranged in a core tube II 22 of the second-section screw conveyor 4, a screw blade II 13 is arranged on the hollow shaft 7, a steam inlet rotary joint 14 and a steam outlet rotary joint 16 are respectively arranged at two ends of the hollow shaft 7, high-temperature steam is introduced into the hollow shaft 7, the high-temperature steam enters and exits the hollow shaft 7 through the steam inlet rotary joint 14 and the steam outlet rotary joint 16, and the heat conduction area is increased by the rotary screw blade II.

And the second core pipe 22 of the second section of screw conveyor 4 is communicated with the outer sleeve 17 of the first section of screw conveyor 2 through the low-temperature steam conduit 3, and low-temperature steam generated by the heated coal enters the outer sleeve of the first section of screw conveyor through the low-temperature steam conduit 3. The low-temperature steam guide pipe 3 is cleaned by air compression or high-pressure steam pulse type, so that the deposition of fine particles of the coal material is prevented, and a pipeline is prevented from being blocked.

An outer sleeve 17 is arranged outside a first core pipe 21 of the first section of the screw conveyor 2; be equipped with steam outlet 23 on the outer tube 17, steam outlet 23 is equipped with metering device 9, and volume or the quality of discharge steam are measured through metering device 9, as coal charge moisture evaporation parameter, through comparing with the parameter of setting for, obtain the difference, let in high temperature steam volume in the adjustment second section screw conveyer 4, realize the accurate control of coal charge humidity. The water vapor outlet 23 is provided with a pump 10 to form micro negative pressure, so that the evaporation of the water in the coal material is accelerated, and the formation of dust is avoided.

The discharge hole of the first section of screw conveyor 2 is connected with the feed hole of the second section of screw conveyor 4 through a feeding chute 11; the feed inlet of the first section of screw conveyor 2 is provided with a star-shaped feeder 1, and the second section of screw conveyor 4 is provided with a coal outlet 15.

A solid shaft 18 is arranged in a core tube I21 of the first section of the screw conveyor 2, and a screw blade I20 is arranged on the solid shaft 18.

The second stage screw conveyor 4 of the present invention has two configurations:

the structure I is as follows: in the first embodiment, high-temperature steam is introduced into the hollow shaft 7 to indirectly heat the coal material in the second section of screw conveyor 4. And a steam sleeve 12 is arranged outside the second core pipe 22 of the second-stage screw conveyor 4, high-temperature steam is introduced into the steam sleeve 12, and meanwhile, the coal material in the second core pipe 22 of the second-stage screw conveyor 4 is heated and dried.

The structure II is as follows: in the second embodiment, the insulating layer 19 is arranged outside the second core pipe 22 of the second spiral conveyor 4, and the high-temperature steam introduced into the hollow shaft 7 indirectly heats the coal material in the second spiral conveyor 4.

A method for controlling humidity of coal materials on line adopts the control system, and comprises the following steps:

and monitoring the moisture metering information generated by the evaporation of the coal material on line in real time, feeding the moisture metering information back to the PID control system, comparing the moisture metering information with the set parameters to obtain the difference, and performing on-line accurate control on the humidity of the coal material.

And the moisture metering information generated by the coal evaporation at least comprises the volume or the mass of the water vapor generated by the coal evaporation.

The on-line accurate control of the coal moisture at least comprises the following three adjusting modes:

1. the total amount of high-temperature steam entering the second section of screw conveyor 4 is kept unchanged, and the change of the coal material flow entering the first section of screw conveyor 2 is realized by adjusting the frequency of a star-shaped feeder motor, so that the accurate control of coal material humidifying is realized;

2. keeping the coal material flow entering the first section of screw conveyor 2 unchanged, and realizing accurate control of coal material humidifying by adjusting the flow of high-temperature steam entering the second section of screw conveyor;

3. and meanwhile, the frequency of the star-shaped feeder motor and the flow of high-temperature steam entering the second section of screw conveyor are adjusted, so that the accurate control of coal moisture control is realized.

The coal material gets into first section screw conveyer 2 and second section screw conveyer 4 in proper order, and the high-temperature steam that lets in carries out indirect heating to the coal material in the second section screw conveyer 4, and the low-temperature steam that the coal material that is heated produced gets into the outer tube 17 of first section screw conveyer 2 through low-temperature steam pipe 3, preheats the coal material that first section screw conveyer carried, forms two effect evaporation.

The water vapor outlet 23 on the outer sleeve 17 of the first section of the screw conveyor 2 is provided with a metering device 9, the volume or the mass of the discharged water vapor is metered by the metering device 9 and is used as a water evaporation parameter of the coal material, and the difference is obtained by comparing the water evaporation parameter with a set parameter, so that the on-line accurate control of the humidity of the coal material is carried out.

The water vapor outlet 23 is provided with a pump 10 to form micro negative pressure, so that the evaporation of the water in the coal material is accelerated, and the formation of dust is avoided. And a low-temperature steam guide pipe between the first section of screw conveyor and the second section of screw conveyor is cleaned by air compression or high-pressure steam in a pulse mode, so that the deposition of fine particles of coal materials is prevented, and pipelines are prevented from being blocked. The first screw blade 20 and the second screw blade 13 of the first screw conveyor section and the second screw conveyor section increase the heat conduction area through rotation.

The steam supply amount of the high-temperature steam in the second section of screw conveyor is adjusted through an adjusting valve, and the adjusting valve adjusts the steam supply amount of the high-temperature steam in the hollow shaft 7; if high-temperature steam is introduced into the steam sleeve 12 outside the core tube II 22 of the second section of the screw conveyor 4, the regulating valve can regulate the steam supply amount of the high-temperature steam of the steam sleeve 12.

FIG. 1 illustrates that coal materials needing moisture regulation are conveyed to a temporary storage or transfer station through a star-shaped feeder 1, a first section of screw conveyor 2 and a second section of screw conveyor 4.

High-temperature steam enters the second section of screw conveyor 4 through the steam metering and adjusting device 6, heats coal materials in the second section of screw conveyor (the blades can increase the heat transfer area), and the high-temperature steam is discharged through the steam outlet 8.

The coal material in the second section of screw conveyer is heated at high temperature, part of low-temperature steam generated by the coal material enters the outer sleeve 17 of the first section of screw conveyer through the low-temperature steam conduit 3, and the coal material in the first section of screw conveyer is preheated by utilizing the principle of double-effect evaporation.

The water vapor generated by cooling in the outer sleeve 17 of the first section of the screw conveyor is guided by the pump 10, flows directionally, and is metered by the metering device 9. And according to the measurement result, the frequency of the motor of the star-shaped feeder is adjusted through a PID control system, so that the change of the coal material flow is realized. Or the flow of high-temperature steam entering the second section of screw conveyor is adjusted through the steam metering and adjusting device 6, so that the steam generated by coal material humidifying is increased or reduced, and the accurate control of the coal material humidifying is realized.

FIG. 2 illustrates:

in the first embodiment, the second spiral blade is arranged in the second core pipe of the second spiral conveyor, so that the heat conduction area is effectively increased in the heat exchange process. During the rotation of the hollow shaft of the second section of screw conveyer, the second helical blade can be in continuous slight impact contact with the coal material, so that the steam generated by heating the wet coal material is quickly guided into the outer sleeve 17 of the first section of screw conveyer by the low-temperature steam guide pipe 3 to be cooled. The high temperature steam enters and exits the hollow shaft through the steam inlet rotary joint 14 and the steam outlet rotary joint 16 at the end parts.

The continuous coal enters the second section of screw conveyor through the feeding chute 11, is guided out through the coal outlet 15 and enters the next storage or transfer station.

Because the pump guides the steam generated by the wet coal through the outer sleeve 17 and the low-temperature steam conduit 3, micro negative pressure is formed in the inner space of the second section coal screw conveyer. The coal does not form dust when passing through the coal outlet 15.

High-temperature steam can be introduced into the space formed by the steam sleeve 12, so that the heat conduction area is increased.

The rotary joint used in the invention belongs to a mature product, is convenient to select and has low cost. The steam can utilize low-heat value waste steam, and the heat exchange is completed in a closed environment, so that the steam diffusion or dust raising is avoided.

FIG. 3 illustrates:

in the second embodiment, if high-temperature steam is introduced only through the hollow shaft 7, the object can be achieved. And an insulating layer 19 is arranged outside the core pipe of the second section of the screw conveyor to replace the steam sleeve 12 in the first embodiment.

FIG. 4 illustrates:

coal of the first section of screw conveyor enters from the star feeder 1 and enters the second section of screw conveyor through the discharging chute 1. The water vapor generated by cooling in the outer sleeve 17 of the first section of the screw conveyor is guided by the pump 10, flows directionally, and is metered by the metering device 9. And according to the measurement result, the frequency of the motor of the star-shaped feeder is adjusted through a PID control system, so that the change of the coal material flow is realized. Or the flow of high-temperature steam entering the second section of screw conveyor is adjusted through the steam metering and adjusting device 6, so that the steam generated by coal material humidifying is increased or reduced, and the accurate control of the coal material humidifying is realized.

FIG. 5 illustrates:

the process flow of the invention is as follows: coal enters a first section of screw conveyor 2 through a star-shaped feeder 1 and enters a second section of screw conveyor 4 through a discharging chute 11;

a heat source (high-temperature steam) enters the hollow shaft 7 through a regulating valve (steam metering and adjusting device 6), the high-temperature steam indirectly heats the coal material in the second section of screw conveyor 4, the low-temperature steam generated by the heated coal material enters the outer sleeve 17 of the first section of screw conveyor 2 through the low-temperature steam guide pipe 3, and the coal material conveyed by the first section of screw conveyor is preheated to form double-effect evaporation;

guiding the water vapor generated in the outer sleeve 17 of the first section of the screw conveyor by the pump 10 to flow directionally, and metering the water vapor by the metering device 9; according to the measurement result, the frequency of the motor of the star-shaped feeder is adjusted through a PID control system, so that the change of the coal material flow is realized; or the flow of high-temperature steam entering the second section of screw conveyor is adjusted through the steam metering and adjusting device 6, so that the steam generated by coal material humidifying is increased or reduced, and the accurate control of the coal material humidifying is realized.