阅读说明：本技术 一种循环供气清粉气流分级装置 (Clear whitewashed air current grading plant of circulation air feed ) 是由 龙海明 王海英 郭志猛 郝俊杰 刘立新 张志刚 裴广林 陈风华 陈晓冬 于 2019-12-11 设计创作，主要内容包括：本发明公开了一种循环供气清粉气流分级装置,包括多级气流分级设备、循环供气设备、循环清粉设备；多级气流分级设备包括旋振筛、储料罐、螺旋送料器、气流分级机、旋风分离器、除尘过滤器；旋振筛、储料罐、螺旋送料器、气流分级机依次连接,旋风分离器多个并联,再与气流分级机串联,除尘过滤器多个并联,旋风分离器与除尘过滤器连接；循环供气设备包括压缩机、精密过滤器、冷干机、自动补气装置,闭环连接；循环清粉设备包括反吹储气罐,反吹储气罐与除尘过滤器、冷干机连接；除尘过滤器与压缩机连接,冷干机与气流分级机连接。本装置可分选多个粒度段粉体,可用于活性金属粉末分级,循环利用气体进行清粉,操作便捷,运行效率高,节约成本。(The invention discloses a circulating air supply and powder removal air flow grading device which comprises a multi-stage air flow grading device, a circulating air supply device and a circulating powder removal device; the multi-stage airflow grading equipment comprises a rotary vibration sieve, a storage tank, a spiral feeder, an airflow grader, a cyclone separator and a dust removal filter; the rotary vibration sieve, the material storage tank, the spiral feeder and the airflow classifier are sequentially connected, a plurality of cyclone separators are connected in parallel and then connected with the airflow classifier in series, a plurality of dust removing filters are connected in parallel, and the cyclone separators are connected with the dust removing filters; the circulating gas supply equipment comprises a compressor, a precision filter, a cold dryer and an automatic gas supplementing device which are connected in a closed loop; the circulating powder cleaning equipment comprises a back-blowing gas storage tank, and the back-blowing gas storage tank is connected with the dust removal filter and the cold dryer; the dust removing filter is connected with the compressor, and the cold dryer is connected with the airflow classifier. This device can select a plurality of granularity section powders, can be used to active metal powder and classify, and the clear powder of cyclic utilization gas, the simple operation, and the operating efficiency is high, practices thrift the cost.)

1. A circulating air supply and powder removal air flow grading device is characterized by comprising a multi-stage air flow grading device, a circulating air supply device and a circulating powder removal device; the multistage airflow grading equipment comprises a rotary vibration sieve, a storage tank, a spiral feeder, an airflow grader, a cyclone separator and a dust removal filter; the cyclone separators are connected in parallel, and are connected in series with the air classifier respectively through pipelines provided with pneumatic butterfly valves, the dust removing filters are connected in parallel, and each cyclone separator is connected with each dust removing filter through a pipeline provided with two pneumatic butterfly valves; the circulating gas supply equipment comprises a compressor, a precision filter, a cold dryer and an automatic gas supplementing device; the compressor is connected with the precision filter through a pipeline, the precision filter is connected with the cold dryer through a pipeline, a flow regulating valve is arranged between the cold dryer and the automatic air supply device through a pipeline, a pneumatic stop valve is arranged between the cold dryer and the airflow classifier through a pipeline, and the automatic air supply device is connected with the compressor through a pipeline; the circulating powder cleaning equipment comprises a back-blowing gas storage tank, wherein a pipeline of an electromagnetic valve is arranged between the back-blowing gas storage tank and each dust removal filter, and a pipeline of a pressure regulating valve and an electromagnetic valve are sequentially arranged between the back-blowing gas storage tank and the cold dryer; and the dust removal filter is connected with the compressor through a pipeline which is sequentially provided with a pneumatic butterfly valve and an exhaust valve.

2. The air flow classification device for the dust removal of the circulating air supply according to claim 1, characterized in that the multistage air flow classification equipment further comprises an ultrasonic rotary vibration sieve; the spiral feeder is connected with the ultrasonic rotary vibration sieve through a pipeline.

3. The classifying device for the dust-removing airflow of the circulating air supply device according to claim 1, wherein the circulating air supply device further comprises a safety filter; the safety filter is arranged between the compressor and the dust removal filter, specifically, a pipeline connection of a pneumatic butterfly valve, an exhaust valve and a safety valve is sequentially arranged between the dust removal filter and the safety filter, and the safety filter is connected with the compressor pipeline.

4. The air flow classifier for cleaning dust in circulating air supply of claim 1, wherein the cyclone separator is connected in parallel by three, a pipeline with a pneumatic butterfly valve is arranged between each cyclone separator and the air flow classifier, and a pipeline with two pneumatic butterfly valves is arranged between each cyclone separator and each dust filter.

5. The classifying device for the dust-removing airflow of the circulating air supply as claimed in claim 1, wherein the dust-removing filter is two filters connected in parallel.

6. The classifying device for the dust-removing air flow of the circulating air supply according to claim 1, wherein each dust-removing filter is provided with a differential pressure sensor.

Technical Field

The invention relates to the technical field of powder grading, in particular to a circulating air supply powder cleaning airflow grading device.

Background

The rotary vibration sieve is the most common grading equipment in the powder industry, has high sieving efficiency, but is difficult to sieve fine powder with the particle size below 300 meshes.

For fine powder classification, the air flow classification equipment is commonly used in the industry, and the general air flow classification equipment is a classification system consisting of a separator, a cyclone separator, a dust removal filter and an induced draft fan. The airflow classification equipment can effectively separate fine powder below 300 meshes, but the separation of multi-granularity-section powder adopts a structure that a separator, a cyclone separator, a cyclone separator and the like are sequentially connected in series, so that the separation efficiency is low and the cost is high.

The open-loop fan is generally adopted for the airflow classification equipment, air is used as a classification medium, explosion is easily caused to combustible powder, the quality of powder products is affected, inert gas is not recycled, a large amount of gas is wasted, and the operation cost is increased.

For the problem that fine powder blocks a dust removal filter in airflow classification equipment, external gas is generally used for fine powder blocking and cleaning, the use of extra supplied gas can increase the operation cost, and the external gas also acts on fine powder blocking and cleaning once, so that a great deal of waste of gas resources can be caused.

Disclosure of Invention

In view of this, the embodiment of the present invention is expected to provide a circulating air supply powder cleaning airflow classification device, which can separate powder in multiple particle size sections, and has the advantages of convenient operation, high separation efficiency and low cost; the method is suitable for active metal powder separation, and gas is recycled without causing gas waste; the cyclic utilization gas is subdivided and blocked and cleaned, additional gas supply is not needed, gas resources are saved, the operation cost is reduced, and the continuous powder grading work is not influenced.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a circulating air supply and powder cleaning air flow grading device comprises a multi-stage air flow grading device, a circulating air supply device and a circulating powder cleaning device; the multistage airflow grading equipment comprises a rotary vibration sieve, a storage tank, a spiral feeder, an airflow grader, a cyclone separator and a dust removal filter; the cyclone separators are connected in parallel, and are connected in series with the air classifier respectively through pipelines provided with pneumatic butterfly valves, the dust removing filters are connected in parallel, and each cyclone separator is connected with each dust removing filter through a pipeline provided with two pneumatic butterfly valves; the circulating gas supply equipment comprises a compressor, a precision filter, a cold dryer and an automatic gas supplementing device; the compressor is connected with the precision filter through a pipeline, the precision filter is connected with the cold dryer through a pipeline, a flow regulating valve is arranged between the cold dryer and the automatic air supply device through a pipeline, a pneumatic stop valve is arranged between the cold dryer and the airflow classifier through a pipeline, and the automatic air supply device is connected with the compressor through a pipeline; the circulating powder cleaning equipment comprises a back-blowing gas storage tank, wherein a pipeline of an electromagnetic valve is arranged between the back-blowing gas storage tank and each dust removal filter, and a pipeline of a pressure regulating valve and an electromagnetic valve are sequentially arranged between the back-blowing gas storage tank and the cold dryer; and the dust removal filter is connected with the compressor through a pipeline which is sequentially provided with a pneumatic butterfly valve and an exhaust valve.

Further, the multistage airflow classification equipment also comprises an ultrasonic rotary vibration sieve; the spiral feeder is connected with the ultrasonic rotary vibration sieve through a pipeline.

Further, the circulating gas supply equipment further comprises a safety filter; the safety filter is arranged between the compressor and the dust removal filter, specifically, a pipeline connection of a pneumatic butterfly valve, an exhaust valve and a safety valve is sequentially arranged between the dust removal filter and the safety filter, and the safety filter is connected with the compressor pipeline.

Preferably, the cyclone separators are connected in parallel, a pipeline of a pneumatic butterfly valve is arranged between each cyclone separator and the airflow classifier, and a pipeline of two pneumatic butterfly valves is arranged between each cyclone separator and each dust removal filter.

Preferably, the dust removal filters are connected in parallel.

Furthermore, each dust removal filter is provided with a differential pressure sensor.

The invention has the following beneficial effects: 1) the powder with a plurality of particle size sections can be sorted, the operation is convenient, the sorting efficiency is high, and the cost is reduced; 2) the method can be suitable for sorting combustible powder such as active metal and the like, gas is recycled, gas waste is avoided, and the cost is reduced; 3) the cyclic utilization gas is subdivided and blocked and cleaned, additional gas supply is not needed, gas resources are saved, the operation cost is reduced, and continuous work of powder separation is not influenced.

Drawings

FIG. 1 is a schematic structural diagram of a circulating air supply and dust removal air flow classification device according to an embodiment of the present invention;

wherein: the device comprises a rotary vibration sieve 1, a material storage tank 2, a spiral feeder 3, an airflow classifier 4, a cyclone separator 5, a dust removal filter 6, a pressure sensor 7, a pneumatic butterfly valve 8, a compressor 9, a precision filter 10, a freeze dryer 11, an automatic air supply device 12, an automatic flow control valve 13, a manual flow control valve 14, a normally open manual ball valve 15, a pneumatic stop valve 16, a back-blowing air storage tank 17, an electromagnetic valve 18, a pressure regulating valve 19, an exhaust valve 20, an ultrasonic rotary vibration sieve 21, a pressure difference sensor 22, a safety filter 23 and a safety valve 24.

Detailed Description

So that the manner in which the features and aspects of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings.

Fig. 1 is a schematic structural diagram of a circulating air supply and dust removal air flow classification device according to an embodiment of the present invention, as shown in fig. 1, including a multi-stage air flow classification device, a circulating air supply device, and a circulating dust removal device; the multistage airflow grading equipment comprises a rotary vibration sieve 1, a material storage tank 2, a spiral feeder 3, an airflow grader 4, a cyclone separator 5 and a dust removal filter 6; the air classifier is internally provided with a pressure sensor 7, the rotary vibration sieve 1 is connected with a material storage tank 2 through a pipeline, the material storage tank 2 is connected with a spiral feeder 3 through a pipeline, a pneumatic butterfly valve 8 is arranged between the spiral feeder 3 and the air classifier 4 through a pipeline, a plurality of cyclone separators 5 are connected in parallel, the cyclone separators are respectively connected with the air classifier 4 through a pipeline provided with the pneumatic butterfly valve 8 in series, a plurality of dust removing filters 6 are connected in parallel, and two pneumatic butterfly valves 8 are arranged between each cyclone separator 5 and each dust removing filter 6 through pipelines; the circulating gas supply equipment comprises a compressor 9, a precision filter 10, a cold dryer 11 and an automatic gas supply device 12; the compressor 9 is connected with the precision filter 10 through a pipeline, the precision filter 10 is connected with the cold dryer 11 through a pipeline, a flow regulating valve is arranged between the cold dryer 11 and the automatic air supply device 12 through a pipeline, a pneumatic stop valve 16 is arranged between the cold dryer 11 and the air classifier 4 through a pipeline, and the automatic air supply device 12 is connected with the compressor 9 through a pipeline; the circulating powder cleaning equipment comprises a back-blowing air storage tank 17, wherein a pipeline of an electromagnetic valve 18 is arranged between the back-blowing air storage tank 17 and each dust removal filter 6, and a pipeline of a pressure regulating valve 19 and an electromagnetic valve 18 are sequentially arranged between the back-blowing air storage tank 17 and the cold dryer 11; and a pipeline connection of a pneumatic butterfly valve 8 and an exhaust valve 20 is sequentially arranged between the dust removal filter 6 and the compressor 9.

Further, the multistage airflow classification equipment also comprises an ultrasonic rotary vibration sieve 21; the spiral feeder 3 is connected with the ultrasonic rotary vibration sieve 21 through a pipeline.

Further, the circulation gas supply apparatus further includes a safety filter 23; the safety filter 23 is arranged between the compressor 9 and the dust removing filter 6, specifically, a pipeline connection of a pneumatic butterfly valve 8, an exhaust valve 20 and a safety valve 24 is sequentially arranged between the dust removing filter 6 and the safety filter 23, and the safety filter 23 is connected with the compressor 9 through a pipeline.

Preferably, the cyclone separators 5 are connected in parallel, a pipeline of a pneumatic butterfly valve 8 is arranged between each cyclone separator 5 and the airflow classifier 4, and a pipeline of two pneumatic butterfly valves 8 is arranged between each cyclone separator 5 and each dust removal filter 6.

Here, cyclone 5 takes a plurality of parallelly connected, preferably takes three cyclone 5 to connect in parallel, every cyclone 5 is connected with air classifier 4 and dust removal filter 6 through pneumatic butterfly valve 8 respectively, when carrying out the powder classification, only open a cyclone 5 and air classifier 4 work through pneumatic butterfly valve 8, two other cyclones 5 are out of work, realize the powder classification of a granularity section, can realize the powder classification of different granularity sections in proper order through the pneumatic butterfly valve 8 that sets up, compare in the existing classifier of adopting repeatedly, cyclone series structure, only need an air classifier, sorting efficiency also obtains improving when equipment cost reduces.

Here, the apparatus of this embodiment is further provided with an ultrasonic rotary vibration sieve 21, specifically, one storage tank 2 is connected to one cyclone 5 through a pipeline, the storage tank 2 is connected to one spiral feeder 3 through a pipeline provided with a pneumatic butterfly valve 8, and the spiral feeder 3 is connected to the ultrasonic rotary vibration sieve 21 through a pipeline; like this when needs further accurate screening, open this pneumatic butterfly valve 8 that sets up and can make the powder enter into the ultrasonic wave and sieve the fine powder more accurately more than 300~500 meshes in shaking the sieve soon, when need not further sieve, can close this pneumatic butterfly valve 8 that sets up, make the powder store in storage tank 2.

Preferably, the dust-removing filter 6 takes two parallel connections.

Further, a differential pressure sensor 22 is provided on each of the dust removing filters 6.

Here, the present apparatus employs a circulation gas supply device, wherein the refrigeration dryer 11 is connected to the gas classifier 4 through a pneumatic stop valve 16, the compressor 9 is connected to the dust removing filter 6 through an exhaust valve 20 and a pneumatic butterfly valve 8, in order to further enhance the usage of circulation gas filtration protection, the safety filter 23 may be additionally disposed between the compressor 9 and the dust removing filter 6, specifically, a pipeline connection of the pneumatic butterfly valve 8, the exhaust valve 20 and a safety valve 24 is sequentially disposed between the dust removing filter 6 and the safety filter 23, and the safety filter 23 is connected to the compressor 9 through a pipeline; the circulating gas supply equipment can enable gas to circularly work through the airflow classifier 4, the cyclone separator 5, the dust removal filter 6, the safety filter 23, the compressor 9, the precision filter 10, the cold dryer 11, the airflow classifier 4 and the like, compared with the existing open-loop equipment, the waste of a large amount of disposable gas is avoided, particularly for combustible powder classification, inert gas is required, and the operation cost can be greatly saved.

The safety filter 23 is used to prevent dust which is not filtered by the dust removing filter from entering the compressor, and the dust entering the compressor can block the air valve of the compressor, which may cause explosion danger in serious cases. On one hand, the gas passing through the dust removal filter is filtered again, so that the purity of the compressed near-inlet gas is improved; on one hand, the filter material of the dust removal filter is prevented from falling off or being damaged, and a large amount of dust enters the compressor.

The compressor 9 pressurizes the low-pressure gas from the inlet of the compressor, and the gas is used in stages; the precision filter 10 can remove dust, water and oil from the gas at the outlet of the compressor; the cooling dryer 11 cools and cools the compressed gas from the outlet of the compressor.

Here, the circulation air supply equipment of the embodiment is provided with one automatic flow control valve 13, one normally-open hand ball valve 15, one manual flow control valve 14, the automatic flow control valve 13 is connected in series with the normally-open hand ball valve 15, and is connected in parallel with the manual flow control valve 14, the automatic flow control valve 13 is in a normally-open state, the manual flow control valve 14 is in a normally-closed state, when the automatic flow control valve 13 is damaged and fails, the normally-open hand ball valve 15 connected in series with the automatic flow control valve 13 is closed, the manual flow control valve 14 is opened, one of the two flow control valves is kept in a.

Under the condition that the pneumatic stop valve 16 is closed and the automatic flow regulating valve 13 is fully opened, the compressor 9 is started, airflow is discharged from the outlet of the compressor 9, returns to the inlet of the compressor 9 through the precision filter 10, the cold dryer 11, the normally open hand ball valve 15, the automatic flow regulating valve 13, the automatic air supply device 12, the safety valve 24 and the safety filter 23, and forms a loop, and the airflow does not enter the multistage airflow classification equipment at the moment.

When the pneumatic stop valve 16 is opened, the gas flow enters the multistage gas flow classifying device, and the opening degree of the automatic flow regulating valve 13 is regulated (reduced) at this time to control the gas amount and pressure entering the multistage gas flow classifying device.

The device adjusts the pressure balance of the device according to the pressure value fed back by the pressure sensor 7 arranged on the air classifier 4; when the feedback air pressure value is larger than the set value, the exhaust valve 20 is opened to exhaust partial air from the device so as to reduce the air pressure value of the whole device; when the feedback value is smaller than the set value, the automatic exhaust system 12 opens the air supply to increase the whole pressure value of the device, and the device keeps the dynamic balance of the air pressure in the process.

Here, the device adopts a circulating powder cleaning device, wherein the back-blowing air storage tank 17 is connected to the dust removing filters 6 through the arranged electromagnetic valve 18, preferably, two dust removing filters 6 are connected in parallel in this embodiment, that is, the back-blowing air storage tank 17 is respectively connected to the two dust removing filters 6 through the arranged electromagnetic valve 18, and in addition, the back-blowing air storage tank 17 is connected to the cold dryer 11 through the sequentially arranged pressure regulating valve 19 and electromagnetic valve 18; setting the powder cleaning air pressure through a pressure regulating valve 19 after a certain time according to experience, opening a pipeline passage through an electromagnetic valve 18 to enable air to enter, and entering a dust removal filter 6 through a back-blowing air storage tank 17 to perform fine powder blockage cleaning; or a pressure difference sensor 22 arranged on the dust removing filter 6 is used for providing a pressure signal, when the pressure in the dust removing filter 6 is higher than a set value, the pressure of the dust removing filter is set through a set pressure regulating valve 19, a set electromagnetic valve 18 is used for opening a pipeline passage so that gas enters, the gas enters the dust removing filter 6 through a back blowing gas storage tank 17 for fine powder blockage cleaning, the cleaned powder is moved out through the bottom of the dust removing filter 6, and the gas is filtered and reused through a circulating gas supply device; the opening and closing of the electromagnetic valve 18 between the back-blowing gas storage tank 17 and the dust removal filter 6 can enable one or more dust removal filters to carry out powder cleaning work, and the rest dust removal filters still normally participate in powder separation work.

The specific working flows of the multistage air classification device, the circulating air supply device and the circulating powder cleaning device in the embodiment are respectively described in detail below.

The working process of the multi-stage airflow classification equipment comprises the following steps: powder enters a storage tank 2 through a rotary vibration sieve 1, the rotating speeds of a spiral feeder 3 and an airflow classifier 4 are set before reaching the spiral feeder 3, the pneumatic butterfly valve 8 and the pneumatic butterfly valves 8 on two sides of a cyclone separator 5 are opened, meanwhile, gas required by powder classification enters the airflow classifier 4, after the powder sequentially enters the spiral feeder 3 and the airflow classifier 4, the powder in the particle size section corresponding to the set rotating speed enters the corresponding cyclone separator 5 and falls and is separated from the lower opening of the cyclone separator, powder screening work in the particle size section is realized, gas can be mixed with some unseparated fine powder and enters a dust removal filter 6 through the pneumatic butterfly valve 8, some mixed fine powder can be filtered and falls and is separated from the lower opening of the dust removal filter 6, and the gas enters a circulating gas supply device; the powder screening of another particle size section is realized only by opening the pneumatic butterfly valves at two sides of another cyclone separator, setting the rotating speed of the airflow classifier and closing the pneumatic butterfly valves at two sides of the cyclone separator corresponding to the powder screening of the previous particle size section, so that the powder of the particle size section corresponding to the set rotating speed falls from the lower opening of the cyclone separator for separation, and the powder screening work of one particle size section is realized; the pneumatic butterfly valve 8 between the spiral feeder 3 and the air classifier 4 is kept in a normally open state when the powder is subjected to normal multi-stage screening, the pneumatic butterfly valve 8 can be closed when the powder is not required to be subjected to multi-stage screening, and simple powder screening work is carried out through the rotary vibration screen 1 alone at the moment; in addition, the ultrasonic rotary vibration sieve 21 is additionally arranged in the embodiment, specifically, a pipeline at the lower opening of one cyclone separator 5 is connected with one storage tank 2, the lower end of the storage tank 2 is connected with one spiral feeder 3 through a pipeline provided with a pneumatic butterfly valve 8, and the spiral feeder 3 is connected with the ultrasonic rotary vibration sieve 21 through a pipeline, so that when the powder needs to be further accurately sieved, the pneumatic butterfly valve 8 arranged is opened, the powder can enter the ultrasonic rotary vibration sieve 21 to more accurately sieve the fine powder with the particle size of more than 300-500 meshes, and when the powder does not need to be further sieved, the pneumatic butterfly valve 8 arranged can be closed, and the powder is stored in the storage tank 2.

The working process of the circulating gas supply equipment comprises the following steps: the method comprises the steps that firstly, gas is supplied through an automatic gas supply device, when powder is normally screened, a pneumatic stop valve 16 is in an open state, the gas from a dust removal filter 6 enters an airflow classifier 4 in multi-stage airflow classification equipment through a compressor 9, a precision filter 10 and a cold dryer 11 and a set pneumatic stop valve 16, the gas from the dust removal filter 6 in the multi-stage airflow classification equipment enters the compressor 9, the precision filter 10 and the cold dryer 11 through a set pneumatic butterfly valve 8 and an exhaust valve 20 to be filtered, and finally, the gas is circulated again into the airflow classifier 4 with the pneumatic stop valve 16 to carry out next cycle of circulation work; in addition, a safety filter 23 and a corresponding safety valve 24 are additionally provided in the present embodiment, specifically, the dust removal filter 6 is connected to the safety filter 23 through a pneumatic butterfly valve 8, an exhaust valve 20 and a safety valve 24, the safety filter 23 is connected to the compressor 9 through a pipeline, so that the gas after coming out of the dust removal filter 6 firstly enters the safety filter 23 for filtering, then enters the compressor 9, a precision filter 10 and a freeze dryer 11 for further filtering, and finally circulates again into the air classifier 4 provided with a pneumatic stop valve 16 for the next cycle.

The working process of the circulating powder cleaning equipment comprises the following steps: because during powder screening of the particle size section, gas can be mixed with some unseparated fine powder and enters the dust removal filter 6 through the arranged pneumatic butterfly valve, although the dust removal filter 6 can filter and separate some fine powder, some fine powder can still remain in the dust removal filter 6 and is adsorbed on the surface of the filter material of the dust removal filter 6, a large amount of residual powder is accumulated after long-time accumulation, so that the internal pressure difference of the dust removal filter 6 is increased, at the moment, a pressure difference signal can be detected through a pressure difference sensor 22 arranged on the dust removal filter 6, at the moment, the work is required to be carried out through a circulating powder cleaning device, specifically, an electromagnetic valve 18 and a set pressure regulating valve 19 are firstly opened, the gas can enter the back blowing gas storage tank 17, and then the gas can enter the corresponding dust removal filter 6 to carry out fine powder blockage cleaning work by opening the corresponding electromagnetic valve 18, the cleaned powder is removed from the bottom of the dust removal filter 6, and the gas is filtered by a circulating gas supply device for reuse; the opening and closing of the electromagnetic valve 18 between the back-blowing gas storage tank 17 and the dust removal filter 6 can enable one or more dust removal filters to carry out powder cleaning work, and the rest dust removal filters still normally participate in powder separation work.

The pneumatic shut-off valve 16 arranged between the air dryer 11 and the air classifier 4 works in particular: when the device is used, the first circulating air supply work of the circulating air supply equipment is needed, the pneumatic stop valve 16 is in a closed state at the moment, and when the powder is normally screened, the pneumatic stop valve 16 is kept in a normally open state.

The pneumatic butterfly valves 8 arranged on both sides of the cyclone separator 5 work in detail: this embodiment has set up such equipment subassembly of three groups, and the powder is sieved the during operation, and the pneumatic butterfly valve 8 of only using a set of cyclone 5 and both sides in same time quantum, and the pneumatic butterfly valve of only a set of cyclone both sides is the open mode in same time quantum promptly, and remaining two sets of pneumatic butterfly valve are in the closed mode.

The pneumatic butterfly valve 8, arranged between the screw feeder 3 and the air classifier 4, works in particular: when the multistage airflow classification equipment normally works, the pneumatic butterfly valve 8 is in a normally open state.

The pneumatic butterfly valve 8 arranged between the cyclone 5 and the dust filter 6 works in particular: opening the pneumatic butterfly valve 8 means that the gas enters the corresponding dust removal filter 6, and two dust removal filters 6 connected in parallel are provided in the embodiment, so that one of the pneumatic butterfly valves 8 or both of the pneumatic butterfly valves 8 can be opened according to the requirement of the powder screening workload.

The pneumatic butterfly valve 8, arranged between the dust removal filter 6 and the safety filter 23, works in particular: the opening of the pneumatic butterfly valve 8 means that gas can enter the safety filter 23 through the exhaust valve 20 and the safety valve 24, and two dust removal filters 6 which are connected in parallel are arranged in the embodiment, and the pneumatic butterfly valve 8 is in a normally open state.

The exhaust valve 20 arranged between the dust removal filter 6 and the safety filter 23 works in particular: when the powder is normally screened and circularly cleaned, the powder is in a normally closed state, and when the feedback air pressure value of the pressure sensor 7 is greater than a set value, the exhaust valve 20 opens and exhausts partial gas to reduce the pressure value of the whole device.

The safety valve 24 provided between the dust removal filter 6 and the safety filter 23 works in particular: the safety valve is kept in a normally closed state, when the gas flow and the pressure in the device are abnormal and are higher than the set pressure value, and the exhaust valve 20 is not in time to exhaust the pressure, the safety valve 24 is opened to release the pressure, so that the pressure in the whole device is ensured to be within the range of the set pressure allowable value.

The flow control valve arranged between the cold dryer 11 and the automatic air supply device 12 works specifically: this embodiment has set up an automatic flow control valve 13, a hand ball valve 15 that normally opens, a manual flow control valve 14, automatic flow control valve 13 and the hand ball valve 15 that normally opens establish ties, and parallelly connected with manual flow control valve 14, automatic flow control valve 13 is in normally open state, manual flow control valve 14 is in normally closed state, when automatic flow control valve 13 damages failure, close the hand ball valve 15 that normally opens who establishes ties with automatic flow control valve 13, open manual flow control valve 14, one keeps normally open state among the two flow control valves of realization.

Under the condition that the pneumatic stop valve 16 is closed and the automatic flow regulating valve 13 is fully opened, the compressor 9 is started, airflow is discharged from the outlet of the compressor 9, returns to the inlet of the compressor 9 through the precision filter 10, the cold dryer 11, the normally open hand ball valve 15, the automatic flow regulating valve 13, the automatic air supply device 12, the safety valve 24 and the safety filter 23, and forms a loop, and the airflow does not enter the multistage airflow classification equipment at the moment.

When the pneumatic stop valve 16 is opened, the gas flow enters the multistage gas flow classifying device, and the opening degree of the automatic flow regulating valve 13 is regulated (reduced) at this time to control the gas amount and pressure entering the multistage gas flow classifying device.

The pressure regulating valve 19 and the electromagnetic valve 18 arranged between the cold dryer 11 and the back blowing air storage tank 17 work specifically: the solenoid valve 18 and the pressure regulating valve 19 are kept normally closed when the fine powder clogging cleaning operation is not required, and the pressure regulating valve 19 and the solenoid valve 18 are opened in this order when the fine powder clogging cleaning operation is required.

The electromagnetic valve 18 arranged between the back-blowing air storage tank 17 and the dust removing filter 6 works specifically: in this embodiment, two dust removing filters 6 are connected in parallel, and when the corresponding dust removing filter 6 needs to be cleaned from the clogging of the fine powder, the corresponding electromagnetic valve 18 is opened, and the remaining time is in a normally closed state.

The device and parts related in the device are all the existing equipment on the market, in the embodiment, the rotary vibration sieve is of a KLD1000-1S type, the storage tank is of a DN500 type, the spiral feeder is of a 50-2S type double-spiral feeder, the air classifier is of a KW-F300 type, the cyclone separator is of a DN300 type, the dust removal filter is of a DN800 type, the ultrasonic rotary vibration sieve is of a KLD1000-3S type, the safety filter is of a DN400 type, the compressor is of an LU-55W-8T type, the precision filter is of a JG-36-50 type, the cold dryer is of a JL-150WT type, the automatic air supply device is of a ZAZP type, the back blowing air storage tank is of a phi 219 & gt 1000 cylindrical tank body, the differential pressure sensor is of an HCCY100 type, and the pressure sensor is of an SMC-PSE532-M5 type.

The existing common pneumatic butterfly valve, the exhaust valve, the automatic flow regulating valve, the electromagnetic valve, the pressure regulating valve, the differential pressure sensor, the pressure sensor and the automatic air supply device are all connected with a common PLC controller in the field on the market, the connection mode is also the existing common mode, specifically, the PLC controller selected in the embodiment is an ohm dragon CP1H-M40DR, and the pneumatic butterfly valve is connected with a switching value input point and an output point of the PLC through an electromagnetic two-position five-way valve;

the exhaust valve is connected with the switching value input and output points of the PLC through the electromagnetic two-position five-way valve;

the automatic flow regulating valve is connected with analog quantity input and output points of the PLC;

the electromagnetic valve is directly connected with the switching value input and output points of the PLC;

the pressure regulating valve is a manual pressure regulating valve, and the pressure is directly set and regulated by regulating a knob on the pressure regulating valve;

the differential pressure sensor and the pressure sensor are respectively connected with an analog quantity input point of the PLC;

a controller in the automatic air supply device is connected with analog quantity input and output points of the PLC;

it should be noted that the connection relationship between each component and the PLC controller in the present device is a conventional connection manner, and is not a part of the protection claimed by the present invention, and should be known to those skilled in the art.

The specific working flow of the circulating air supply and powder cleaning airflow grading device provided by the embodiment of the invention is as follows:

powder enters a storage tank through a rotary vibration sieve, the rotating speeds of a spiral feeder and an airflow classifier are set before the powder reaches the spiral feeder, the pneumatic butterfly valves and the pneumatic butterfly valves on two sides of a cyclone separator are opened, meanwhile, gas required by powder classification enters the airflow classifier, the powder sequentially enters the spiral feeder and the airflow classifier, the powder in the particle size section corresponding to the set rotating speed enters the corresponding cyclone separator and falls and is separated from the lower opening of the cyclone separator, powder screening work of a particle size section is realized, gas can be mixed with some unseparated fine powder and enters a dust removal filter through the arranged pneumatic butterfly valves, some mixed fine powder can be filtered and falls and is separated from the lower opening of the dust removal filter, and the gas enters a circulating gas supply device; the powder screening of another particle size section is realized only by opening the pneumatic butterfly valves at two sides of another cyclone separator, setting the rotating speed of the airflow classifier and closing the pneumatic butterfly valves at two sides of the cyclone separator corresponding to the powder screening of the previous particle size section, so that the powder of the particle size section corresponding to the set rotating speed falls from the lower opening of the cyclone separator for separation, and the powder screening work of one particle size section is realized; the pneumatic butterfly valve between the spiral feeder and the airflow classifier is kept in a normally open state when powder is subjected to normal multi-stage screening, the pneumatic butterfly valve can be closed when the powder is not required to be subjected to multi-stage screening, and simple powder screening work is carried out through the rotary vibration screen at the moment; in addition, the ultrasonic rotary vibration sieve is additionally arranged in the embodiment, specifically, a pipeline at the lower opening of one cyclone separator is connected with a storage tank, the lower end of the storage tank is connected with a spiral feeder through a pipeline provided with a pneumatic butterfly valve, the spiral feeder is connected with the ultrasonic rotary vibration sieve through a pipeline, so that when the powder needs to be further accurately sieved, the set pneumatic butterfly valve is opened to enable the powder to enter the ultrasonic rotary vibration sieve to more accurately sieve the fine powder with the granularity of more than 300-500 meshes, and when the powder does not need to be further sieved, the set pneumatic butterfly valve can be closed to enable the powder to be stored in the storage tank.

The gas enters the circulating gas supply equipment, specifically, the gas passes through a pneumatic butterfly valve, an exhaust valve and a safety valve arranged on a dust removal filter, enters the safety filter for primary gas filtration, then enters the compressor, the precision filter and the cold dryer for further filtration, and then enters the airflow classifier again through a pneumatic stop valve arranged on the airflow classifier for powder screening;

the dust removal filter can accumulate a large amount of residual powder during long-time work to further cause the internal pressure difference of the dust removal filter to be increased, a pressure difference signal can be detected through a pressure difference sensor arranged in the dust removal filter, the dust removal filter needs to work through circulating powder cleaning equipment, specifically, an electromagnetic valve is firstly opened, a pressure regulating valve is set, gas can enter a back-blowing gas storage tank, then the gas can enter the corresponding dust removal filter to perform fine powder blockage cleaning work by opening a corresponding electromagnetic valve, the cleaned powder is moved out through the bottom of the dust removal filter, and the gas is filtered and reused through circulating gas supply equipment; the electromagnetic valve switching between blowback gas holder and the dust removal filter can make one or more dust removal filter clear powder work, and remaining dust removal filter still normally participates in powder and selects separately the work, compares in current external gas and carries out disposable farine and block up the clearance and use, can the gas resources are practiced thrift, reduces the running cost, and does not influence the powder and select separately continuation work.

The specific type of the above-mentioned devices is not limited and detailed, and the deep connection mode of the above-mentioned devices is not detailed, and can be understood by those skilled in the art as the common general knowledge.

The embodiments of the present invention are only described in the detailed description, and the scope of the present invention is not limited thereto. Since the present invention can be modified by a person skilled in the art, the present invention is not limited to the embodiments described above.