在經濟持續快速發展的大背景下，一些行業在生產運輸的過程當中產生的環境污染越來越得到重視，如水泥廠、制藥廠、食品加工廠等運輸的顆狀物、粉粒料等。在這種情況下，氣力輸送技術得到了逐步的推廣。氣力輸送代替了傳統的機械輸送物料，它是一種采用密封式輸送管道的方式輸送物料的工藝過程。

　　Against the backdrop of sustained and rapid economic development, environmental pollution generated during the production and transportation processes in some industries, such as cement plants, pharmaceutical plants, food processing plants, etc., is receiving increasing attention. In this situation, pneumatic conveying technology has gradually been promoted. Pneumatic conveying has replaced traditional mechanical conveying of materials, and it is a process that uses sealed conveying pipelines to transport materials.

　　氣力輸送

　　Pneumatic conveying

　　氣力輸送是一種借助壓縮氣流在管道內輸送散體顆粒的物料搬運技術，是實現散體物料綠色、安全、便捷輸送運輸的有效措施。氣力輸送的第一次大規模應用是19世紀后期的谷物真空輸送，到20年代中期，谷物的負壓和正壓輸送已很普遍。自此以后，氣力輸送技術蓬勃發展，輸送物料范疇擴展到涵蓋各種各樣的固體顆粒。該技術在應用過程中，以下優勢逐漸突出：無塵綠色、走線靈活、多點配送、成本低廉、安全可靠、易于自動控制。

　　Pneumatic conveying is a material handling technology that uses compressed air flow to transport loose particles in pipelines. It is an effective measure to achieve green, safe, and convenient transportation of loose materials. The first large-scale application of pneumatic conveying was grain vacuum conveying in the late 19th century. By the mid-1920s, negative and positive pressure conveying of grains had become common. Since then, pneumatic conveying technology has flourished, and the scope of conveying materials has expanded to cover various solid particles. In the application process, the following advantages of this technology gradually become prominent: dust-free and green, flexible wiring, multi-point distribution, low cost, safety and reliability, and easy automatic control.

　　氣力輸送系統構成

　　Composition of pneumatic conveying system

　　氣力輸送系統主要由四部分組成：動力源、供料裝置、輸送裝置、分離裝置，每個部分都需要專用硬件設備來實現所需的要求。進行一次完整的氣力輸送，需要依次完成：動力源提供壓縮氣流—供料器供給物料顆粒—輸送裝置完成管道運輸與分流—分離裝置將物料顆粒與氣流分離。

　　The pneumatic conveying system mainly consists of four parts: power source, feeding device, conveying device, and separation device, each of which requires dedicated hardware equipment to achieve the required requirements. To carry out a complete pneumatic conveying, it is necessary to complete the following steps in sequence: the power source provides compressed air flow, the feeder supplies material particles, the conveying device completes pipeline transportation and diversion, and the separation device separates material particles from the air flow.

　　氣力輸送系統構成示意圖

　　Schematic diagram of pneumatic conveying system composition

　　動力源是氣力輸送系統中必不可少的元件，包括各種類型的壓縮機、鼓風機、風扇和真空泵等。在氣力輸送系統設計時，需要確定實現可靠輸送所需的氣流和壓力（正壓或負壓）。

　　The power source is an essential component in pneumatic conveying systems, including various types of compressors, blowers, fans, and vacuum pumps. When designing a pneumatic conveying system, it is necessary to determine the airflow and pressure (positive or negative) required to achieve reliable conveying.

　　在供料裝置，根據物料顆粒運動在不同區域內變化規律的不同，可以將供料裝置內部區域劃分為混合區、加速區、穩定輸送區。在混合區，固體顆粒被引入流動的氣流中。由于固體進入流場時基本上處于靜止狀態，因此當固體與流動的氣體混合時會發生較大的動量變化，這種勢能變化是加速區的主要特征。加速區通常由一段一定長度的水平管道組成，被設計用于加速固體顆粒到某種“穩定”流動狀態。

　　In the feeding device, the internal area of the feeding device can be divided into a mixing zone, an acceleration zone, and a stable conveying zone based on the different patterns of material particle movement in different regions. In the mixing zone, solid particles are introduced into the flowing airflow. Due to the fact that solids enter the flow field in a basically static state, significant momentum changes occur when they mix with flowing gases, and this potential energy change is the main characteristic of the acceleration zone. The acceleration zone is usually composed of a horizontal pipeline of a certain length, designed to accelerate solid particles to a certain "stable" flow state.

　　在氣固分離裝置內，物料顆粒從氣流中分離出來。分離工作主要借助特定的氣固分離系統完成，選擇合適的氣固分離系統取決于許多因素，其中最重要的是固體顆粒的大小。根據固體顆粒特性的不同，可以使用許多不同配置的氣固分離系統分離物料。旋風分離器以其幾何簡單、分離效果好、維護方便和價格低廉的優點，在工業中廣泛用于從氣體中分離灰塵或用于產品回收。

　　In the gas-solid separation device, material particles are separated from the gas flow. The separation work is mainly accomplished through specific gas-solid separation systems, and the selection of a suitable gas-solid separation system depends on many factors, among which the most important is the size of solid particles. According to the different characteristics of solid particles, many different configurations of gas-solid separation systems can be used to separate materials. Cyclone separators are widely used in industry for separating dust from gases or for product recycling due to their advantages of simple geometry, good separation efficiency, easy maintenance, and low cost.

　　氣力輸送系統分類及應用

　　Classification and Application of Pneumatic Conveying Systems

　　1、按照輸送實質分類

　　1. Classified according to the essence of transportation

　　由于輸送物料種類不同，對應的氣力輸送的種類也非常多。但整體概括來看，氣力輸送可以分為四類：筒式氣力輸送、稀相氣力輸送、濃相動壓氣力輸送、濃相靜壓氣力輸送。

　　Due to the different types of conveyed materials, there are also many corresponding types of pneumatic conveying. But overall, pneumatic conveying can be divided into four categories: cylinder pneumatic conveying, dilute phase pneumatic conveying, dense phase dynamic pressure pneumatic conveying, and dense phase static pressure pneumatic conveying.

　　筒式氣力輸送按照裝料筒的類型可分為有輪傳輸筒、無輪傳輸筒兩類。在輸送時，先將物料裝到傳輸筒中，之后使傳輸筒在管道中通過空氣的靜壓作用進行高速滑行。筒式氣力輸送適用于輸送一些不易懸浮并且自身無法成栓的成件貨物，其應用范圍較小。

　　Cylinder pneumatic conveying can be divided into two types according to the type of loading cylinder: wheeled conveying cylinder and non wheeled conveying cylinder. During transportation, the material is first loaded into the conveyor drum, and then the conveyor drum slides at high speed through the static pressure of air in the pipeline. Cylinder pneumatic conveying is suitable for conveying some finished goods that are not easily suspended and cannot be tied up by themselves, and its application range is relatively small.

　　稀相氣力輸送也被稱為稀相動壓輸送，因為物料的運輸依靠高速空氣形成的動能。一般采用氣流的速度為12~40m/s，料氣比為1~5，最大值為15。稀相氣力輸送通常適用于輸送距離較短，被輸送的物料處于干燥的易流動的狀態，并且其質量與顆粒大小均較小的情況。

　　Dilute phase pneumatic conveying, also known as dilute phase dynamic pressure conveying, relies on the kinetic energy generated by high-speed air for material transportation. Generally, the airflow velocity is 12-40m/s, the material to gas ratio is 1-5, and the maximum value is 15. Dilute phase pneumatic conveying is usually suitable for situations where the conveying distance is short, the conveyed material is in a dry and easy to flow state, and its mass and particle size are small.

　　在濃相動壓氣力輸送系統中，管道中的物料以密集狀態依靠空氣動能進行輸送，管道不會因物料密集而堵塞，氣流速度在8~15m/s。這樣流動狀態的氣力輸送裝置主要有高壓壓送式、高真空吸送式和流態化氣力輸送裝置。料氣比（通過管道截面的物料與空氣的流量比值）范圍較大，前兩者的料氣比范圍為15~20，第三種用于輸送粉狀物料，料氣比在200以上。

　　In the dense phase dynamic pressure pneumatic conveying system, the material in the pipeline is transported in a dense state relying on the kinetic energy of air, and the pipeline will not be blocked due to the dense material. The airflow velocity is between 8-15m/s. The pneumatic conveying devices in such a flowing state mainly include high-pressure pressure conveying, high vacuum suction conveying, and fluidized pneumatic conveying devices. The range of material to air ratio (the ratio of the flow rate of material to air through the cross-section of the pipeline) is relatively large. The first two have a material to air ratio range of 15-20, while the third type is used for conveying powdered materials with a material to air ratio of over 200.

　　在濃相靜壓氣力輸送中，物料密集并且栓塞管道，依靠著空氣的靜壓來輸送物料。濃相靜壓氣力輸送分為栓流和柱流兩種。栓流氣力輸送是目前中距離輸送方式中最好的輸送技術，它通過人為的操作預先將料柱切割，使料柱長度變短。在輸送物料過程中，氣栓和料栓間隔分開使得料栓輸送速度得以提高，輸送壓力得以降低，物料的輸送距離得以提高。在柱流氣力輸送裝置中，物料以密集狀態接續不斷地充滿管道，進而形成料柱，輸送時物料移動速度僅有0.2~2m/s，因此僅適用于30米以內的短距離輸送。

　　In dense phase static pressure pneumatic conveying, materials are densely packed and blocked in pipelines, relying on the static pressure of air to transport materials. Dense phase static pressure pneumatic conveying is divided into two types: plug flow and column flow. Plug flow pneumatic conveying is currently the best conveying technology among medium distance conveying methods. It involves manually cutting the material column in advance to shorten its length. During the process of conveying materials, the separation of air plugs and material plugs allows for an increase in the conveying speed of the material plugs, a decrease in conveying pressure, and an increase in the conveying distance of the materials. In the column flow pneumatic conveying device, the material continuously fills the pipeline in a dense state, forming a material column. The material movement speed during conveying is only 0.2~2m/s, so it is only suitable for short distance conveying within 30 meters.

　　2、按照輸送裝置分類

　　2. According to the classification of conveying devices

　　按照氣力輸送系統的輸送裝置類型（空氣在管道中的壓力狀態）來分可將氣力輸送系統分為三類：正壓式輸送、負壓式輸送和混合輸送。

　　According to the type of conveying device (pressure state of air in the pipeline) of the pneumatic conveying system, it can be divided into three categories: positive pressure conveying, negative pressure conveying, and mixed conveying.

　　正壓式輸送一般是指在輸送系統的前端借助壓縮機或鼓風機產生壓縮空氣，進而形成管道起點與終點間的壓差，氣流裹挾著物料輸送至接料處，最后物料與空氣在接料處分離。正壓式輸送系統中，物料不直接經過風機，所以輸送物料不會導致風機被磨損并且風機的葉片也不會導致物料破碎。正壓式氣力輸送系統常用于面粉廠產品的輸送。

　　Positive pressure conveying generally refers to the use of a compressor or blower to generate compressed air at the front end of the conveying system, thereby forming a pressure difference between the starting and ending points of the pipeline. The airflow carries the material to the receiving point, and finally separates the material from the air at the receiving point. In a positive pressure conveying system, materials do not directly pass through the fan, so conveying materials will not cause the fan to wear out and the blades of the fan will not cause material breakage. Positive pressure pneumatic conveying system is commonly used for conveying products in flour mills.

　　負壓式輸送一般將真空泵安裝在系統的末端，由于環境壓力大于管道壓力，由真空泵引起的負壓差將空氣與物料吸入管道中，并被送至分離器進行分離，空氣由上部排出送入除塵器凈化，而物料則由分離器底部卸出。負壓輸送適用于從多處向一處集中輸送物料。該系統常用于白糖、豆類、米類等物料的運輸。其次，因輸送氣流的壓力比大氣壓力要低，水分易蒸發，與正壓輸送式相比，該系統更容易輸送含水分多的物料。除此之外，該系統還適用于船舶、火車等卸料，應用范圍十分廣泛。

　　Negative pressure conveying generally installs a vacuum pump at the end of the system. Due to the ambient pressure being greater than the pipeline pressure, the negative pressure difference caused by the vacuum pump sucks air and materials into the pipeline and sends them to the separator for separation. The air is discharged from the upper part and sent to the dust collector for purification, while the materials are discharged from the bottom of the separator. Negative pressure conveying is suitable for transporting materials from multiple locations to a centralized location. This system is commonly used for the transportation of materials such as white sugar, beans, and rice. Secondly, due to the lower pressure of the conveying airflow compared to atmospheric pressure, moisture is easily evaporated. Compared with positive pressure conveying, this system is easier to transport materials with higher moisture content. In addition, the system is also suitable for unloading materials from ships, trains, etc., with a wide range of applications.

　　在一個輸送系統中由負壓式和正壓式兩部分組成，通過利用兩種不同系統的優勢組成的系統稱為混合輸送系統。混合式氣力輸送系統通常應用于較為復雜的輸送當中。

　　A mixed conveying system consists of two parts, negative pressure and positive pressure, and is formed by utilizing the advantages of these two different systems. Hybrid pneumatic conveying systems are typically used in more complex conveying systems.

　　小結：

　　Summary:

　　氣力輸送系統已深入到現代化產業生產的各領域，成為建材、化工、糧食、冶金、采礦、環保、輕工、能源等行業普遍使用的方法。如何使氣力輸送系統在滿足生產要求的同時能夠穩定運行、低速、低耗，是如今對氣力輸送系統研究的主要趨勢。可以毫不夸張的說，氣力輸送系統技術的發展及應用，前景不可限量。在經濟持續快速發展的大背景下，一些行業在生產運輸的過程當中產生的環境污染越來越得到重視，如水泥廠、制藥廠、食品加工廠等運輸的顆狀物、粉粒料等。在這種情況下，氣力輸送技術得到了逐步的推廣。氣力輸送代替了傳統的機械輸送物料，它是一種采用密封式輸送管道的方式輸送物料的工藝過程。

　　The pneumatic conveying system has penetrated into various fields of modern industrial production, becoming a widely used method in industries such as building materials, chemical, grain, metallurgy, mining, environmental protection, light industry, and energy. How to ensure stable operation, low speed, and low consumption of pneumatic conveying systems while meeting production requirements is currently the main trend in research on pneumatic conveying systems. It can be said without exaggeration that the development and application of pneumatic conveying system technology have unlimited prospects. Against the backdrop of sustained and rapid economic development, environmental pollution generated during the production and transportation processes in some industries, such as cement plants, pharmaceutical plants, food processing plants, etc., is receiving increasing attention. In this situation, pneumatic conveying technology has gradually been promoted. Pneumatic conveying has replaced traditional mechanical conveying of materials, and it is a process that uses sealed conveying pipelines to transport materials.

　　氣力輸送

　　Pneumatic conveying

　　氣力輸送是一種借助壓縮氣流在管道內輸送散體顆粒的物料搬運技術，是實現散體物料綠色、安全、便捷輸送運輸的有效措施。氣力輸送的第一次大規模應用是19世紀后期的谷物真空輸送，到20年代中期，谷物的負壓和正壓輸送已很普遍。自此以后，氣力輸送技術蓬勃發展，輸送物料范疇擴展到涵蓋各種各樣的固體顆粒。該技術在應用過程中，以下優勢逐漸突出：無塵綠色、走線靈活、多點配送、成本低廉、安全可靠、易于自動控制。

　　Pneumatic conveying is a material handling technology that uses compressed air flow to transport loose particles in pipelines. It is an effective measure to achieve green, safe, and convenient transportation of loose materials. The first large-scale application of pneumatic conveying was grain vacuum conveying in the late 19th century. By the mid-1920s, negative and positive pressure conveying of grains had become common. Since then, pneumatic conveying technology has flourished, and the scope of conveying materials has expanded to cover various solid particles. In the application process, the following advantages of this technology gradually become prominent: dust-free and green, flexible wiring, multi-point distribution, low cost, safety and reliability, and easy automatic control.

　　氣力輸送系統構成

　　Composition of pneumatic conveying system

　　氣力輸送系統主要由四部分組成：動力源、供料裝置、輸送裝置、分離裝置，每個部分都需要專用硬件設備來實現所需的要求。進行一次完整的氣力輸送，需要依次完成：動力源提供壓縮氣流—供料器供給物料顆粒—輸送裝置完成管道運輸與分流—分離裝置將物料顆粒與氣流分離。

　　The pneumatic conveying system mainly consists of four parts: power source, feeding device, conveying device, and separation device, each of which requires dedicated hardware equipment to achieve the required requirements. To carry out a complete pneumatic conveying, it is necessary to complete the following steps in sequence: the power source provides compressed air flow, the feeder supplies material particles, the conveying device completes pipeline transportation and diversion, and the separation device separates material particles from the air flow.

　　氣力輸送系統構成示意圖

　　Schematic diagram of pneumatic conveying system composition

　　動力源是氣力輸送系統中必不可少的元件，包括各種類型的壓縮機、鼓風機、風扇和真空泵等。在氣力輸送系統設計時，需要確定實現可靠輸送所需的氣流和壓力（正壓或負壓）。

　　The power source is an essential component in pneumatic conveying systems, including various types of compressors, blowers, fans, and vacuum pumps. When designing a pneumatic conveying system, it is necessary to determine the airflow and pressure (positive or negative) required to achieve reliable conveying.

　　在供料裝置，根據物料顆粒運動在不同區域內變化規律的不同，可以將供料裝置內部區域劃分為混合區、加速區、穩定輸送區。在混合區，固體顆粒被引入流動的氣流中。由于固體進入流場時基本上處于靜止狀態，因此當固體與流動的氣體混合時會發生較大的動量變化，這種勢能變化是加速區的主要特征。加速區通常由一段一定長度的水平管道組成，被設計用于加速固體顆粒到某種“穩定”流動狀態。

　　In the feeding device, the internal area of the feeding device can be divided into a mixing zone, an acceleration zone, and a stable conveying zone based on the different patterns of material particle movement in different regions. In the mixing zone, solid particles are introduced into the flowing airflow. Due to the fact that solids enter the flow field in a basically static state, significant momentum changes occur when they mix with flowing gases, and this potential energy change is the main characteristic of the acceleration zone. The acceleration zone is usually composed of a horizontal pipeline of a certain length, designed to accelerate solid particles to a certain "stable" flow state.

　　在氣固分離裝置內，物料顆粒從氣流中分離出來。分離工作主要借助特定的氣固分離系統完成，選擇合適的氣固分離系統取決于許多因素，其中最重要的是固體顆粒的大小。根據固體顆粒特性的不同，可以使用許多不同配置的氣固分離系統分離物料。旋風分離器以其幾何簡單、分離效果好、維護方便和價格低廉的優點，在工業中廣泛用于從氣體中分離灰塵或用于產品回收。

　　In the gas-solid separation device, material particles are separated from the gas flow. The separation work is mainly accomplished through specific gas-solid separation systems, and the selection of a suitable gas-solid separation system depends on many factors, among which the most important is the size of solid particles. According to the different characteristics of solid particles, many different configurations of gas-solid separation systems can be used to separate materials. Cyclone separators are widely used in industry for separating dust from gases or for product recycling due to their advantages of simple geometry, good separation efficiency, easy maintenance, and low cost.

　　氣力輸送系統分類及應用

　　Classification and Application of Pneumatic Conveying Systems

　　1、按照輸送實質分類

　　1. Classified according to the essence of transportation

　　由于輸送物料種類不同，對應的氣力輸送的種類也非常多。但整體概括來看，氣力輸送可以分為四類：筒式氣力輸送、稀相氣力輸送、濃相動壓氣力輸送、濃相靜壓氣力輸送。

　　Due to the different types of conveyed materials, there are also many corresponding types of pneumatic conveying. But overall, pneumatic conveying can be divided into four categories: cylinder pneumatic conveying, dilute phase pneumatic conveying, dense phase dynamic pressure pneumatic conveying, and dense phase static pressure pneumatic conveying.

　　筒式氣力輸送按照裝料筒的類型可分為有輪傳輸筒、無輪傳輸筒兩類。在輸送時，先將物料裝到傳輸筒中，之后使傳輸筒在管道中通過空氣的靜壓作用進行高速滑行。筒式氣力輸送適用于輸送一些不易懸浮并且自身無法成栓的成件貨物，其應用范圍較小。

　　Cylinder pneumatic conveying can be divided into two types according to the type of loading cylinder: wheeled conveying cylinder and non wheeled conveying cylinder. During transportation, the material is first loaded into the conveyor drum, and then the conveyor drum slides at high speed through the static pressure of air in the pipeline. Cylinder pneumatic conveying is suitable for conveying some finished goods that are not easily suspended and cannot be tied up by themselves, and its application range is relatively small.

　　稀相氣力輸送也被稱為稀相動壓輸送，因為物料的運輸依靠高速空氣形成的動能。一般采用氣流的速度為12~40m/s，料氣比為1~5，最大值為15。稀相氣力輸送通常適用于輸送距離較短，被輸送的物料處于干燥的易流動的狀態，并且其質量與顆粒大小均較小的情況。

　　Dilute phase pneumatic conveying, also known as dilute phase dynamic pressure conveying, relies on the kinetic energy generated by high-speed air for material transportation. Generally, the airflow velocity is 12-40m/s, the material to gas ratio is 1-5, and the maximum value is 15. Dilute phase pneumatic conveying is usually suitable for situations where the conveying distance is short, the conveyed material is in a dry and easy to flow state, and its mass and particle size are small.

　　在濃相動壓氣力輸送系統中，管道中的物料以密集狀態依靠空氣動能進行輸送，管道不會因物料密集而堵塞，氣流速度在8~15m/s。這樣流動狀態的氣力輸送裝置主要有高壓壓送式、高真空吸送式和流態化氣力輸送裝置。料氣比（通過管道截面的物料與空氣的流量比值）范圍較大，前兩者的料氣比范圍為15~20，第三種用于輸送粉狀物料，料氣比在200以上。

　　In the dense phase dynamic pressure pneumatic conveying system, the material in the pipeline is transported in a dense state relying on the kinetic energy of air, and the pipeline will not be blocked due to the dense material. The airflow velocity is between 8-15m/s. The pneumatic conveying devices in such a flowing state mainly include high-pressure pressure conveying, high vacuum suction conveying, and fluidized pneumatic conveying devices. The range of material to air ratio (the ratio of the flow rate of material to air through the cross-section of the pipeline) is relatively large. The first two have a material to air ratio range of 15-20, while the third type is used for conveying powdered materials with a material to air ratio of over 200.

　　在濃相靜壓氣力輸送中，物料密集并且栓塞管道，依靠著空氣的靜壓來輸送物料。濃相靜壓氣力輸送分為栓流和柱流兩種。栓流氣力輸送是目前中距離輸送方式中最好的輸送技術，它通過人為的操作預先將料柱切割，使料柱長度變短。在輸送物料過程中，氣栓和料栓間隔分開使得料栓輸送速度得以提高，輸送壓力得以降低，物料的輸送距離得以提高。在柱流氣力輸送裝置中，物料以密集狀態接續不斷地充滿管道，進而形成料柱，輸送時物料移動速度僅有0.2~2m/s，因此僅適用于30米以內的短距離輸送。

　　In dense phase static pressure pneumatic conveying, materials are densely packed and blocked in pipelines, relying on the static pressure of air to transport materials. Dense phase static pressure pneumatic conveying is divided into two types: plug flow and column flow. Plug flow pneumatic conveying is currently the best conveying technology among medium distance conveying methods. It involves manually cutting the material column in advance to shorten its length. During the process of conveying materials, the separation of air plugs and material plugs allows for an increase in the conveying speed of the material plugs, a decrease in conveying pressure, and an increase in the conveying distance of the materials. In the column flow pneumatic conveying device, the material continuously fills the pipeline in a dense state, forming a material column. The material movement speed during conveying is only 0.2~2m/s, so it is only suitable for short distance conveying within 30 meters.

　　2、按照輸送裝置分類

　　2. According to the classification of conveying devices

　　按照氣力輸送系統的輸送裝置類型（空氣在管道中的壓力狀態）來分可將氣力輸送系統分為三類：正壓式輸送、負壓式輸送和混合輸送。

　　According to the type of conveying device (pressure state of air in the pipeline) of the pneumatic conveying system, it can be divided into three categories: positive pressure conveying, negative pressure conveying, and mixed conveying.

　　正壓式輸送一般是指在輸送系統的前端借助壓縮機或鼓風機產生壓縮空氣，進而形成管道起點與終點間的壓差，氣流裹挾著物料輸送至接料處，最后物料與空氣在接料處分離。正壓式輸送系統中，物料不直接經過風機，所以輸送物料不會導致風機被磨損并且風機的葉片也不會導致物料破碎。正壓式氣力輸送系統常用于面粉廠產品的輸送。

　　Positive pressure conveying generally refers to the use of a compressor or blower to generate compressed air at the front end of the conveying system, thereby forming a pressure difference between the starting and ending points of the pipeline. The airflow carries the material to the receiving point, and finally separates the material from the air at the receiving point. In a positive pressure conveying system, materials do not directly pass through the fan, so conveying materials will not cause the fan to wear out and the blades of the fan will not cause material breakage. Positive pressure pneumatic conveying system is commonly used for conveying products in flour mills.

　　負壓式輸送一般將真空泵安裝在系統的末端，由于環境壓力大于管道壓力，由真空泵引起的負壓差將空氣與物料吸入管道中，并被送至分離器進行分離，空氣由上部排出送入除塵器凈化，而物料則由分離器底部卸出。負壓輸送適用于從多處向一處集中輸送物料。該系統常用于白糖、豆類、米類等物料的運輸。其次，因輸送氣流的壓力比大氣壓力要低，水分易蒸發，與正壓輸送式相比，該系統更容易輸送含水分多的物料。除此之外，該系統還適用于船舶、火車等卸料，應用范圍十分廣泛。

　　Negative pressure conveying generally installs a vacuum pump at the end of the system. Due to the ambient pressure being greater than the pipeline pressure, the negative pressure difference caused by the vacuum pump sucks air and materials into the pipeline and sends them to the separator for separation. The air is discharged from the upper part and sent to the dust collector for purification, while the materials are discharged from the bottom of the separator. Negative pressure conveying is suitable for transporting materials from multiple locations to a centralized location. This system is commonly used for the transportation of materials such as white sugar, beans, and rice. Secondly, due to the lower pressure of the conveying airflow compared to atmospheric pressure, moisture is easily evaporated. Compared with positive pressure conveying, this system is easier to transport materials with higher moisture content. In addition, the system is also suitable for unloading materials from ships, trains, etc., with a wide range of applications.

　　在一個輸送系統中由負壓式和正壓式兩部分組成，通過利用兩種不同系統的優勢組成的系統稱為混合輸送系統。混合式氣力輸送系統通常應用于較為復雜的輸送當中。

　　A mixed conveying system consists of two parts, negative pressure and positive pressure, and is formed by utilizing the advantages of these two different systems. Hybrid pneumatic conveying systems are typically used in more complex conveying systems.

　　小結：

　　Summary:

　　氣力輸送系統已深入到現代化產業生產的各領域，成為建材、化工、糧食、冶金、采礦、環保、輕工、能源等行業普遍使用的方法。如何使氣力輸送系統在滿足生產要求的同時能夠穩定運行、低速、低耗，是如今對氣力輸送系統研究的主要趨勢。可以毫不夸張的說，氣力輸送系統技術的發展及應用，前景不可限量。

　　The pneumatic conveying system has penetrated into various fields of modern industrial production and become a commonly used method in industries such as building materials, chemical, grain, metallurgy, mining, environmental protection, light industry, and energy. How to ensure stable operation, low speed, and low consumption of pneumatic conveying systems while meeting production requirements is currently the main trend in research on pneumatic conveying systems. It can be said without exaggeration that the development and application of pneumatic conveying system technology have unlimited prospects.

　　本文由  氣力輸送系統 友情奉獻.更多有關的知識請點擊  http://www.ezhixun.com/   真誠的態度.為您提供為全面的服務.更多有關的知識我們將會陸續向大家奉獻.敬請期待.

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