Vacuum conveying is an efficient way to move powder, granules, pellet, plastic materials and etc but not all systems are created the some. Let see how powders pose their own set of challenges and how to handle them.
TeknoConvey testing facilities can test materials and simulate virtually any pneumatic conveying system to identify application needs.
Whether for mixing, extrusion or resin production, it’s important to consider all the variables before choosing a conveying system for powders.
All powder conveying application is unique and differents. But unlike plastic pellets, moving powders can be especially demanding for plastics processors. With powders, it’s critical to consider factors such as conveying rates and distances, material characteristics, flow aids, pick-up and discharge, filtration and safety concerns that can impact the entire operation.
TeknoConvey an industry expert in pneumatic vacuum conveying, we builds material handling systems specifically designed for continuous vacuum conveying powders to gravimetric blenders and other process equipment for applications including extrusion, compounding and resin pellet production.
Compared to mechanical conveying such as bucket elevator screw feeder, vacuum conveying easily accommodates elevation and directional changes in between the source and the destination and is the preferred technology for transporting combustible powders such as resins and polymers. Whether for powders, flakes or fibers, it also improves the accuracy of the process and increases throughput by eliminating the inconsistencies of manual refilling.
There are a few vital components to vacuum conveying:
Material for vacuum conveying
It is crucial to see that how a powder will behave under certain conditions when configuring a vacuum conveying system. In the some industries, a customer might specify whether their material is free-flowing, sluggish or non free flowing, which can effect conveying needs. One product might consist of several grades, with each behaving differently than the other. Some combustible powders present serious safety risks and materials may also behave differently depending on environmental elements such as temperature, elevation or humidity.
For examble whether you’re working with elevation titanium dioxide, iron oxide, zina oxide or calcium carbonate, each type of compound presents its own set of challenges. To understand your materials, you can focus on reducing material degradation and maximizing system efficiency, power consumption and ultimately improving end product quality.
We provide testing facilities to your material in advance can reveal exactly what your conveying system needs to be efficient and safe.
System control of hopper vacuum conveyor
If the pneumatic ejector vacuum pump is the heart of the system, the control panel is the main parts. Even the simplest systems utilize a micro plc to control convey, refill, discharge and pulse functions, and more complex plc control panels are equipped for batch weigh systems and multi ingredient handling systems. These systems weigh material at the pick up point for a loss in weight transfer or at the discharge end of the system for a gain in weight transfer.
Vacuum conveying systems and related controls are ideal for feeder refill, particularly in applications where flakes, pigments, additives, fibers and other materials are added to gravimetric blenders or the continuous feeder refills upstream to the extruder.
Our vacuum receivers from caters to vacuum conveying demands and can convey resin materials up to 12,500 tonnes/hr.
Pickup point for vacuum conveyor
Pickup points so many times require the most customization and attention in the system. The pickup point can be configured with a wand for a simple bag dump station, up-and-in by hand system, bulk bag unloader, and in some cases, silo or railcar, all dependent on the container holding the material at the beginning of the process.
Pickup point also poses a challenge for powder when it comes to efficient material transfer. There must be a means to aerate the powder so that it flows freely into the tubing from start to finish. As a result, the pickup point is vital in ensuring quality at the start of the process.
Discharge point for vacuum loader
Powders do not flow like pellets or granules. And not all powders are the same, some powders are cohesive but others tend to bridge , rat-hole or clump when discharged, impeding material flow from the hopper to the material receiver. As a result, it is impotant that the discharge configuration match the material.
Non easy free flowing powders often require the most equipment modifications, and there are a variety of discharge methods to handle these powders, such as over-sized receiver discharge openings as well as 60-70° and other cone less, jam-proof vacuum receivers.
For difficult to move powders, the key is to move the material at a constant rate from the pickup point to the material line and at a constant rate from the discharge point to the material receiver.
Dust filtration of vacuum convey unit
Every time manufacturing environment focuses a great deal on safety, plant sanitation and process efficiency. Systems handle particles measured in microns, some even less than 1 microns and invisible to the human eye that can remain suspended in the air for days. As a result, properly designed air and dust filtration systems are extremely important to the success and safety of any bulk powder handling system. The type of powder and its characteristics will largely dictate the filtration system needed.
With some systems conveying over 12,500 tonnes/hr. of extremely dusty powders, proper filter maintenance is essential for peak system performance. For especially difficult powders, suitable filters and filter replacement can make a major difference. Filters separate the product from the clean air traveling back to the vacuum producer. With ultra-fine powders, filters can clog the conveying process.
TeknoConvey intuitive jet pulse filter cleaning systems to keep all filters running efficiently. Other filtering factors to consider include the material of the filter, number of filters, size of the filter area, filter placement and the cleaning cycle.
Safety of vacuum conveying units
The number one advantage of vacuum conveying for powders is dust control, especially in the powder processes industries, where combustible dust is a serious safety issue. Vacuum conveying is a closed process in which powders are protected from ambient air in the plant. As a result, it is the preferred technology for transporting combustible powders. Some materials present a risk for combustible dust explosion or harmful environmental impact, so the system needs to ensure that the material is contained.
As vacuum conveying automated the material handling process, material can now be conveyed from source to destination, without the need for manual dumping of the powders into the process. This eliminates stair climbing and fugitive dust, improving employee safety.
Pneumatic conveying has proven itself as an efficient way to handle several types of powder materials and has made advancements in automating the entire process, while accommodating even the most challenging materials. Properly designed bulk material transfer systems contribute to the continued success of the system, while reducing maintenance, equipment downtime and power consumption.
Having even a basic understanding of material properties and operation needs is the first step to solving costly conveying problems and cutting costs associated with
Cleaning of vacuum conveyor
Cleaning the conveying line of residual material is vital to process efficiency and quality control for applications requiring change over. For processors using multiple materials, it’s important to quickly and easily clean out the line, pickup, drop off and other components that can interfere with the next batch. When changing materials or recipes, there’s a major risk of contamination. As a result, it’s important to look for features of quick color change and easy cleanout.
Even cohesive and lightweight powders are prone to sticking and can cause bridging and rat holing, so it’s important, especially where change over is concerned, to consider not only your operation as a whole but the materials themselves for a clean operation.