所在位置:首页 >> 耐火材料>> 资讯详情

麦考勃气力输送系统与传统气力输送设备比较090705

作者:佚名发布时间:1970-01-01

低速密相气力输送技术同常规稀相气力输送方式区别

Dense phase pneumatic conveying compare with dilute phase pneumatic conveying

陈春颖 王琨 麦考勃气动输送工程(上海)有限公司

By Chen Chunying / Wang Kun, Macawber China

关键词:气力输送,低速,密相

Keywords:Pneumatic conveying, low-velocity, Dense phase.

美国麦考勃公司对气力输送的基础设计理念是低速密相,即:

1)        物料以较低的速度进行输送(一般在28m/s低于物料的悬浮速度);

2)        输送时的料气比高(一般在30~90之间)。

Macawber’s philosophy of basic design is low velocity and dense phase pneumatic conveying,just as following:

1)Materials is conveyed at a low velocity(generally 28m/s , below the saltation velocity )

2) PhaseMaterial-to-air Ratio at a hign level(generally 30~90)

 

在此输送状态下,物料利用压缩空气的推力以连续的沙丘或栓状沿着输送管道运动而不是通过物料与压缩空气充分混合的吹送。一定程度上,该输送方式允许物料的输送速度可以远远低于悬浮速度,因此避免了传统气力输送由于物料运动速度高而引起的管道磨损问题。同时麦考勃气力输送系统为保证物料在输送管道中始终保持料栓状(类似于沙丘)密相输送,提出了“少量多次”的输送概念,即单次输送较少的物料,通过多次的输送循环来达到实际生产的输送要求。

Using dense phase pneumatic conveying, Material flow patterns are basically a plug or series of plugs along the pipeline impulsed by air pressure,different from material using dilute phase pneumatic conveying flow by mixture with a mass of positive pressure air flow. In this case, Material is conveyed well below the saltation velocity,avoid abrasion of pipeline caused by high velocity. At the same time ,Macawber bring forward conveying less material one circle and complete transfer rate by improve quantity of circle in the same time to keep the material flow as plug all the time.

例如,麦考勃设计生产的灰槽Ashveyor®采用了定制的圆顶阀Dome Valve®作为进料阀,该阀门可以切断静止的料柱关闭阀门。Ashveyor®采用底部出料管,可控制的压缩空气系统安装在灰槽系统Ashveyor®单元的第一个灰槽上。多个给料点的所有Ashveyor®串联到一个输送管道上,布置简单方便。

For example,Macawber’s Ashveyor using special Dome Valve which could cut off all of the static material as inlet Valve, Ashveyor discharge material from bottom of the vessel, air supply system installed on the first Ashveyor of conveying system ensure controllable compressed air flow from first Ashveyor to the last one along the pipeline, multi-Ashveyor using one conveying pipeline make the installation easy.  

完整的麦考勃气力输送系统依靠料位计的信号自动运行,一个为给料仓的低料位计,另一个为目标仓的高料位计。如非特别要求,系统将会自动运行到每一个目标仓料满。系统的电气逻辑控制也可以利用安装在接受仓仓顶的分路阀实现换向功能,将物料输送到任何一个或多个需要的目标仓。

Macawber conveying system automatic operation according to two level probe signal, one is low level probe of fees hopper, the other is hign level probe of silo. If not have specifically requirement, system will automatically run until material fill with silo. System electrical logic control could conrol the dump valve installed on the top of the silo to change the direction of material flow that ensure material conveyed into one or multi-silo.

 

传统的仓式泵一般采用双闸阀作为进料阀,在输送过程中采用“集中一次输送”,即使用大容积的发送罐,然后通过较大的气耗量将物料吹至接受仓。因为一次输送的物料比较多,为防止堵管,会加大输送速度,这样就不能保证物料的输送速度,同时加大了对输送管道的磨损。大容积发送罐带来的又一个问题是为防止大量物料在发送罐内积压结块需要为发送罐增加一个出口阀、在发送罐内增加一套空气流化装置,这样设计结构导致系统运行不稳定并增加了设备的维护量。

Traditional bin pump using the double gate valve as inlet valve.After material filled with large volume vessel, this system using a strong air flow to blow the material into silo. Because of conveying a great many of material,it must to flow at a high velocity to prevent block up pipeline so that material flow velocity is unstable and increase the abrasion of pipeline. Another peoblem is that it must to install a outlet valve at the outlet and one set airlift system in vessel to prevent material mass, this design result in system operation unstable increase maintenance time.

  

比较结果大体汇总如下:

Result of compare:

项目item

麦考勃技术Macawber technic

传统仓泵Traditional bin pump

输送理念

philosophy

密相低速,能耗低,工作可靠。一排灰槽通过一根管路输送,无需补气,助吹等。

Dense phanse, low velocity, operation reliable,low energy consumption,one pipeline,no assistance.

结构决定很难做到密相低速输送。多数有补气、助吹或真空倒吸,能耗高、磨损大。

Hard to dense phase convey,need assistance,high energy consumption,high abrasion.

进料阀

Inlet valve

使用圆顶阀,可以高频率工作(两次检修间隔几十万次循环),在下料过程中穹形阀芯可以切断静止物料,灵活可靠,特殊的结构保证密封效果。实现‘少量多次’输送效果的核心部件。

Using dome valve, high frequency, cut off satic material, flexible and reliable,good seal.

常规阀门如双闸阀等很难做到切断物料的操作,硬密封效果差,没有阀芯磨损后的密封补偿功能。为减少阀门的开启次数一般设计为大容量罐体。

Hard to cut off static material,bad seal, no compensate,large vessel.

设备尺寸

Euipment dimension

‘少量多次’的输送理念,发送罐体积小

Little material multi-times,small vessel

 

为减少进料阀的开闭次数,发送罐体积大,需要安装空间高

Lager vessel, large installing space

发送罐内结构

Vessel configuration

发送罐体积小,罐体内无需料位计及流化装置

Small vessel,no level prpbe,no airlift

发送罐体积大,一次下料多,需要料位计控制下料数量,需要安装排气阀方便下料,物料积累到一定数量时为防止物料在重力作用下结块需要安装流化装置

Lager vessel need level probe to control material level,vessel vent to assistant discharge and airlift to prevent mass.

出料阀

Outlet valve

无需出料阀,发送罐和输送管路直接连通

No outlet valve,

需要安装出料阀,安装在输送管路前,在进料时出料阀关闭

Need to install outlet valve,close when feed

发送罐内压力

Vessel pressure

常压

Ambient

一般在2公斤的压力,在进料后,进料阀和出料阀均关闭,输送用气给罐体加压,然后打开出料阀,突然打开出料阀会导致物料对出料阀的严重磨损

Generally 2 bar, close outlet valve and inlet valve after material filled with vessel;increase pressure before open the outlet valve,if not will cause abrasion of valve.

物料降解

Material degradation

因输送速度低、物料间相对运动少,降解率低,只有少量的物料破碎

 

因物料在管道内流速大,经过输送后物料降解率高

High velocity,high degradation

对块状物料的输送

Transfer mass

 

可以输送大到5060mm粒径的物料

Could conveying 5060mm particle size material.

只能输送粉体

Only convey powder

爬升高度

Vertical height

可以爬升到60的高度

Up to 60M.

因输送空气压力低,难以满足有很大高度的输送要求

 

Low height bacuse of low conveying air pressure.

对接收仓除尘器的要求

Requirment of reception hopper reverse jet filter

耗气量低,除尘器面积小

Low air consumption,small filter

 

耗气量大,除尘器面积大

High air consumption,big filter

 

在气力输送发展的几十年间,气力输送技术已从负压反抽发展到正压输送,在正压输送中简单的通过大量高速气体吹送物料的方式因能耗高、对管道磨损大必将逐步被低能耗、低维护的低速密相输送方式所淘汰。

After several dozens years developing, Pneumatic conveying technic changed from negative pressure conveying to positive pressure conveying,due to high energy consumption and high abrasion, positive pressure dilute phase pneumatic conveying system will be replaced by positive pressure dense phase pneumatic conveying system.