June 20, 2017

Macawber Engineering, Inc. will be featured in Globalspec’s June issue of “Material Handling & Supply Chain Technology”.  Globalspec, also known as Engineering360, is “the world’s largest online destination for engineers, delivering the single source for critical engineering content, information, insight, tools and community for engineers and technical professionals across multiple industries and disciplines”.  Engineering360’s website contains news, products, suppliers and much more.  You can check out our profile on Engineering360 and subscribe to their newsletters by clicking on the links below.




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[P3674] Macawber Group Installation Case Study:

Sodium Bicarbonate Conveying system, Northwich, UK.

In brief:

The dense phase pneumatic conveying system was supplied to convey 14 t/h of sodium bicarbonate over a distance of 26 ft horizontal and 98 ft vertical. The system is an 8 cubic feet Denseveyor® with a 5” pipe line and is located under a feed hopper with start and stop controlled in automatic by the feed hopper and silo reception level probes. The system was first installed in November 1996.  In July 2014 after 17 years of continuous daily operation it was upgraded with a touch screen operator interface, new filling Dome Valve and air manifold. The vessel and pipe line remain originals and are in very good condition expected to offer many more years of service.  The pipe line, bends, and vessel are made from stainless steel 304 with all external surfaces coated in a corrosive resistant clear lacquer.

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Denseveyor installed below a feed hopper




Material Characteristics:

Sodium Bicarbonate            0.004” Mean

Bulk Density                          66 lbs/cu ft

Temperature                        104°F

Moisture Content                0.1%

Condition                               Free flowing




1. Dense phase low velocity conveying

2. Low material degradation

3. Reliable operation




Transfer Capacity                14t/h

Conveying Distance            26ft Horizontal and 98ft vertical

Reception Points                 1 feed and 1 reception point.



  1. Cost savings in terms of energy savings and reduced maintenance
  2. Increased transfer rate
  3. Reduced compressed air requirements
  4. Lower than specified material degradation
  5. Low maintenance
  6. High reliability
  7. Fully integrated into control room DCS
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New system control panel

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Final refurbishing assembly

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Outlet air nozzle with proprietary air flow valve

To find out more information please contact Macawber

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Mactenn Systems, our sister company in the UK, has today announced that Lysair Air Solutions has been appointed as the exclusive representative of Mactenn in Belgium, the Netherlands, and Luxembourg. The company specializes in projects aimed at environmental conservation and is well known for its strength and know-how in providing high quality solutions to dust handling needs from equipment supply to complete installations. By adding our dense-phase pneumatic conveying line to its offering, it is able to add value and scope to its local customers being able to meet a wider range of requirements. The co-operation will strengthen Macawber Group’s international network and adds to our ability to offer installation services to our European customers.


On behalf of the Macawber Group we welcome Lysair to our network of representatives and wish them and Mactenn good luck and many successful installations together.


Contact Lysair at www.lysair.com.


Contact Mactenn at www.mactenn.com


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Dense Phase Pneumatic Transporters

1. Dense phase pneumatic conveying pressure vessels were introduced to the U.S. markets in the early 1960’s.  Pressure vessels were used because the pressures required for dense phase conveying normally exceeded 15 psig – the limit at that time for rotary airlock valves which were used almost exclusively by manufacturers of positive pressure dilute phase systems. In order to accommodate the higher pressures necessary for dense phase conveying systems,  ASME coded vessels became mandatory.


2. The valves available at that time for use, as in-feed to pressure vessels were limited to butterfly valves. Although slide gates were also tried.  There are several problems associated with butterfly valves and slide gates when used as pressure vessel in-feed valves:


a. Butterfly and slide gates valves are not able to cut through a falling or static column of material since the material is trapped between the valve disc and the seat preventing effective sealing when the vessel is pressurized.


Two valves must be used – one above the other.  The upper valve cuts off material flow but does not seal.  The lower valve then closes properly and seals effectively.  (A level probe is necessary in the vessel to sense when the upper valve must close.)


b. When butterfly valves are open, the valve discs are directly in the flow of material.  This not only inhibits flow into the vessel, but also makes the valve susceptible to wear, even with mildly abrasive materials.  The valve deteriorates at an increasing rate and sealing again becomes ineffective.  Often, the valve fails altogether.


c. To avoid poor sealing, the valves must be continuously maintained and often completely replaced – even as frequently as every 2-3 months.


3. To reduce the above effects on the valve, the pressure vessels are designed to cycle infrequently – usually 10 to 12 times per hour.  This reduces the load on the butterfly and/or slide gate valves and extends their wear life.  This means, however, that quite large vessels are used.  For example, a vessel of 15 to 25 cu.ft. conveying through a 4” line is quite common.


4. When the pressure vessel cycles, the material in the vessel is forced out into the pipeline due to the pressure of the air and entrainment of the material with air.  With the arrangement described in item 3 , all of the above material would be forced into the pipeline as a single plug of material, which would be 175 to 250 ft. long depending on the size of the vessel.  The pressure required to transport such a plug would be higher than the available output of a standard compressor, resulting in a blocked pipeline.


The manufacturers of these systems avoid this possibility by “conditioning” the material.  Conditioning typically takes place in the pipeline in the form of pipe line air injectors, sometimes referred to as “boosters”.  The effect of conditioning is to dilute and break up the plug and maintain a high enough velocity to prevent blockages.  Unfortunately, the addition of air through the boosters often causes increased material velocity far in excess of that desired.  The effects of such high velocities are high wear rates on pipelines, high particle attrition, excessive air consumptions, and in spite of the boosters, the risk of a blocked line.


5. Macawber realized that to avoid blockages, the necessity of boosters, high air consumptions and high material velocities, it would be necessary to reduce the plug length in the pipeline.  It was found, through testing, that a plug length in the range of 40 to 60 ft would convey at low velocity and with low air consumption using pressures in the 15 to 40 psig range.

6. To produce such short plugs would require small vessels, and this in turn would require frequent cycles to maintain the desired  conveying rate (40 to 80 cycles/hour normally). Clearly butterfly valves are not going to be suitable to address these requirements. Macawber solved this problem by developing the Dome Valve. The Dome Valve can close through a column of material and seal effectively. The seal is pneumatic and inflates only when the valve is closed. The air pressure in the seal is 80 to 100 psig exceeding the vessel conveying pressure by at least 30 psig. The valve, when open, has no restrictions while filling, and the valve is robustly designed to minimize restrictions. Maintenance time and costs are extremely low.

7. In addition to being able to convey materials at low velocity, the Denseveyor offers other advantages:

a. Low profile-easier to accommodate under silos, bulk bag unloaders, reclaimers, etc. Silo heights can be reduced, thereby reducing structural support costs.

b. Easier to install.

c. Quicker vessel filling times.

d. Smaller filter units (for exhaust air).

e. No pipeline air injection systems required- less installation- less equipment to maintain.

f. Easier access for inspection.

g. Standard schedule 40 pipelines are used.

h. One year, no-wear guarantee on pipeline components.

i. Lower power requirements as a result of low air consumption.

8. The Macawber Design Philosophy has been applied to a wide and diverse range of materials in almost every process industry. This advanced process of pneumatic conveying has been refined and developed since it’s introduction in 1977 and continues to be successfully applied in thousands of installations worldwide.

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What are the reasons for blocked conveying lines?

All pneumatic conveying systems block sometimes.  Clearing a pipeline means downtime, loss of production, and can be a maintenance headache. So ensuring your system runs as smoothly as possible day after day is critical. Here at Macawber we have been designing pneumatic conveying systems for years, using our knowledge and experience to design systems that aim to provide the most reliable and maintenance free systems possible.  We do not like blockages or any other maintenance issues any more than you do. But if they do happen, understanding where to look to minimize downtime is essential.

Here are some pointers for a quick recovery:    

    1. Changes to controls – Sometimes it is essential to modify PLC programming. For instance, adding additional distribution valves, changing the requirements of the weighing system, changing the number of and/or weight of ingredients for a mixer charging system.  Any control changes should be carried out in conjunction with the system manufacturer.  If not, the customer may inadvertently change some of the basic settings, times etc. fundamental to the operation of the pneumatic conveying system.
    2. Out-of-Specification Material – Has your material changed? Is the bulk density, particle size distribution and flowability what the system was designed for? If the answer is no, the blockages could be explained by the material.
    3. Foreign Material – Sometimes foreign objects such as used welding rods, cigarette packs, wire, nuts and bolts, etc. find their way into the silo/feed hopper etc.  As these materials accumulate they create a blockage preventing the conveyed material from entering the conveying line or moving along down the pipeline.
    4. Moisture in the conveying process – Moisture can change the material characteristics. Materials will become sticky or poorly flowing resulting in conveying blockages. For instance, with baghouse and ESP installations there is the possibility that water or steam may enter the hoppers e.g.,  due to a faulty boiler tube/s.  As most types of ash are hygroscopic (they absorb moisture from their surroundings) moisture will change the consistency of the ash and create conveying difficulties.
    5. Air Supply Problems - If the air supply to the conveying system has inadequate pressure, flow and/or contains too much moisture, this can cause the material to slow down in the pipeline. Usually this causes the pressure to rise and if the air supply pressure cannot be maintained through the cycle, the system will block.
    6. Pipeline Incorrectly Installed – Any changes to the original pipe route configuration can cause blockages.  If you have a need to modify a pipe route contact the supplier for verification or for re-configuration and resizing of your system.
    7. Pipe Line Incorrectly Installed – Any changes to the original pipe route configuration can cause blockages.  If you have a need to modify a pipe route contact the supplier for verification or for re-configuration and resizing of your system.
    8. Receiving Bin High Level Probe Failure – Check the operation of the level probes if fitted. Level probes are installed to signal the system that the receiving bin/silo is full (i.e. when the probe is contacted by material) and to shut the system down until the probe is uncovered.  Faulty level probes may allow the system to keep on conveying material to the bin/silo and over fill it. If noticed by the operating personnel, the system will continue to convey, gradually filling the pipeline until it blocks.
    9. Defective Components- Faulty components such as pressure regulators, solenoid valves, etc. can result in failure of the conveying air supply leading to pipeline blockages.

Contact us today to find out more…..   Contact Macawber Engineering, Inc. | Pneumatic Conveying Systems | Macawber

ETI good

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Why is Electric Arc Furnace (EAF) Dust so difficult to convey?


The EAF dust generated in a combustion process by electric arc furnaces employed in steelmaking is a hazardous material containing many heavy metals such as lead, cadmium, zinc, etc. These materials are not only hazardous requiring safe and reliable methods of conveying and disposal but they are also highly abrasive and poorly flowing.  Furthermore EAF dust can have high moisture content. As a result EAF dust is a challenge to convey and special considerations must be applied to the way the material is fed as well as conveyed.  The best way to convey EAF dust is using dense-phase pneumatic conveying which has the ability to convey EAF dust reliably with an added benefit of minimizing pipe wear.

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We have been working for years with various steel industries providing solutions to their unique conveying requirements associated with EAF dust. In a recent project 28 of our Ashveyors are installed  on a common 4” conveying pipeline to receive material from the customer’s EAF Baghouse.  Rotary air locks feed material to through screw conveyors, which in turn deliver the dust to small feed hoppers located above the Ashveyors®.  The Ashveyors® are arranged in 4 lines of 7 vessels with the further 2 units located at the Spark Arrestor Collectors.  Our robust Dome Valves®, capable of providing a completely seal tight enclosure, ensure a reliable process.  This project is the second largest EAF dust project awarded to us this year. The systems  will be supplied to a reputable international engineering house, and will be operational in the US in early 2016.

Learn how we can assist in your EAF conveying process.

To contact Macawber Engineering about your needs today, follow the link below:

Contact Macawber Engineering, Inc. | Pneumatic Conveying Systems | Macawber

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We often get questions from our clients that come in to our service department. Here is a common Q & A

Q. When troubleshooting, should I return to the factory settings?
A. Yes. Every time. When our service technician has completed commissioning your system, you will be sent a record of the machine settings that provided for the optimum conveying conditions.
Return to these settings.
If you cannot locate the factory settings, please call us at 1.800.433.2213 (ext. 120) and ask for Mike DeLand. Or email him at:
We have these on file. If the system is still not functioning correctly, we will be able to assist you with your needs. The problem could be a variety of causes, for instance, a faulty component, a change in the material conditions or air supply, or other minor issue. The advice you receive over the phone is free, so please do not hesitate to give us a call.
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We have successfully tested another 250 mm Stainless Steel 3-way T-Type Diverter Valve to be used for conveying fish food. The Diverter Valve is designed to be used in dense-phase pneumatic conveying applications for handling fragile materials minimizing material breakage. The Diverter Valve is also available in the UK via our sister company, Mactenn.

To find out more information about Macawber Engineering click here

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On any Macawber dense-phase pneumatic conveying system, the quality of the convey air and control air are quoted separately. Why is it important that these specifications are observed on site?

a). The International standard for control air for pneumatic devices is-40 degrees, Pressure Dew Point.

b). This standard may also be applied to conveying air e.g. for most powders, food products, hygroscopic materials, etc. Other materials such as wet coal, silica sand, for instance, would not require dry air. The specification of the conveying air is determined by Application Engineering and/or the customer and is dependent upon the material to be conveyed and the prevailing site climate conditions.

c). The control air supply is always required to be dry to the international standard.

d). If the air supplies are not separated then when the system is in a conveying cycle, the control air pressure can be reduced to an extent that the control functions of the system are affected and a subsequent upset operating condition would occur.


For more information please contact Macawber here

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Solids do not conform to comfortable empirical formula when you pump them along pipelines.  It is often only with exhaustive testing and evaluation that meaningful decisions can be made.

Macawber has always been at the forefront of material handling evaluation technology.  From the very beginning, 40 years ago, we realized that in order to provide the most comprehensive conveying ability in the world we needed the facilities and expertise to assess any material from minerals such as silica sand, gypsum and dolomite, to titanium dioxide and sugar beet pellets. Since the early days we have tested hundred of materials assessing material performance and optimum conveying conditions and while doing it creating an extensive experience and know-how related to powders and especially difficult to handle materials such as fragile and abrasive materials.

A purpose-built full size research, testing and demonstration facility utilizes our dense-phase technology.  Our materials characterization laboratory first performs analysis of bulk materials to achieve a full understanding of bulk material samples before they are presented to the test circuits.  Once the material enters our 2000ft conveying circuit, instrumentation and data acquisition facilities provide a wide range of information relating to the efficiency of the pneumatic process.  Of special significance is our attention to:

air:material ratio to determine the energy efficient performance for material and application;

material velocity which is immensely important for abrasive bulk materials to ensure satisfactory pipeline life;

conveying media demand, which is the profile of conveying gas demand to ensure adequate supply requirements;

Transfer capacity in order to determine correct system size; and

Gas filter requirement.

Once all the data has been collected and analyzed we are ready to discuss with our customers the type of conveying system we consider would be the best solution for our customer’s needs.

Should you have a material that is difficult to handle or you just wish to learn about your material and how it conveys we are here to assist.


Test House Equip 6cleaned

To contact us about your needs click here

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We are pleased to share a testimonial from one of our satisfied customers, Frog Switch.


Cas Koshinski
Executive Vice President, and Chief Operating Officer

I am writing to express our satisfaction with the performance of the Model 8/6-5 Sandpump we’ve recently installed in our foundry no bake sand reclaim circuit. This system is the first time dense phase transfer has been successfully demonstrated at our facility and it likely won’t be the last time as it has gained the confidence of the operators and maintenance group who now support replacement of the other dilute phase systems in the plant.

This project was successful because of (1) the effort Macawber’s sales and engineering group spent early in the project to assess the application and properly specify the system we needed, and (2) the field support group whose onsite service during the installation and startup process was crucial in completing the set up within a timely manner and enabled us to start up the circuit as planned.

This was our first Macawber system, but it likely won’t be our last.

Best Regards,
Cas Koshinski

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One of the notable features of our pneumatic conveying systems is their ability to handle hot materials. We first encountered hot material applications in the foundry industry.  A common application is the handling of hot knock-out sand (the remains of the sand mold after the hot metal has been poured and the casting made) which could reach temperatures of 700-800 degrees F.

The problem with transporting hot material of this nature had always been an effective filling valve that would perform well in these high temperatures.  To address this  need we added to our Dome Valve range a design that could operate at high temperatures without impairment of performance.  Our standard Dome valve operates up to 200 degrees F without any change to its design, and special seals can increase this range to 400 degrees F.  To be able to exceed 400 degree F, we designed our valve to include water cooling up to 660 degrees F.  Today this added capability enables us to address many different and difficult materials handling applications not just within the foundry industry but also in the petrochemical and other industries.

Inflatek Valve 200mm Watercooled top plate P1453MS

To learn more about how we can assist you to solve your unique material handling problems please contact us.  A link to our survey sheet is attached.

Dome Valve 2013 Brochure



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Macawber Engineering Inc. has stayed true to it’s core for over 40 years. While other companies have been distracted by diversification and/or been taken over by larger companies, Macawber has stayed on the course for becoming an expert in everything related to low velocity, dense-phase pneumatic conveying, frequently called in to deal with difficult to handle materials and to solve unique customer requirements.  Our reputation is attributed to our high standards in everything that we do from paying detailed attention to our customers’ needs to reliable and efficient designs, high quality products and customer service.  We truly know what it takes and take great pride in it.

Technology: Low Velocity

Our technology excels due to our knowledge and experience in low velocity pneumatic conveying.  Low velocity, dense-phase pneumatic conveying is the preferred method for many materials handling processes as almost all applications benefit from a regime that that provides the heaviest line loading and the lowest material velocity. These attributes also provide the greatest conveying gas economies for efficient power consumption. The applications that often benefit most from low velocity are related to materials that are difficult to handle with more conventional methods such as mechanical and dilute conveying systems.  In the case of fragile and abrasive materials where eliminating material degradation and wear are important, material is conveyed at 1-3meters/seconds. The main benefits of low velosity conveying are:

* Low air and energy consumption

* No or minimal material degradation

* No or minimal component, pipe and bend wear

* No or minimal material segregation


Our 40-year experience extends to just about every process industry from food to minerals, combustion to chemicals and others, with the ability to handle thousands of materials from pebble lime to peanuts, biomass ash to baby powder.  To-date we has installed over 25,000 systems worldwide, many of which have remained in operation for decades providing an excellent return for investment.  The best systems are designed by people who truly know what they are doing.


Macawber systems are designed in-house with quality, flexibility, reliability and efficiently in mind.  We realize that every requirement is unique and therefore, our equipment is designed to be able to accommodate. Our systems come in different sizes, materials of construction, control options, design pressures and are able to handle temperatures up to 350C and with special design considerations, even higher. We offer a wide range of proprietary ancillary equipment to complement our pneumatic conveying eqipment. And once a scope has been agreed, we can offer installation services.

* Low maintenance with only one moving part

* Robust proprietary Dome Valve in the heart of the system

* User-friendly with simple operations and fully automated controls

* Only few spare parts required

* Limited downtime

* No pipeline air boosters

* Simple installation and retrofit

*Enviromentally friendly; no spillage or dust


Due to our strong focus on quality in system design and our extensive experience we are able to offer a 24 month warranty (terms and conditions apply) which exceeds the standard industry warranty of 12 months, a benefit that add value.  We manage several quality programs addressing product quality, product safety and management performance:

* ISO 9001 Compliant

*ASME Section VIII Certified

*CE Marked (via sister company, Mactenn Systems Ltd.)


Our philosophy is a scientific approach continuously testing new materials be it for our own purposes to better understand and improve our designs or to carry out customer witness testing to demonstrate how their unique material/s will perform in our equipment. We can adapt our tests to closely match the expected conditions on your site. Having a clear understanding of your material’s behavior in our equipment ensures that your system works right the first time, every time.  The purpose-built full size R&D centre and test facility incorporates a materials characterization laboratory for detailed examination of the mechanical properties of bulk materials.


* Experienced technical Support – toll-free

* Replacement parts normally available ex-stock

* Commissioning and Field Service Support

* Factory refurbishments

* Application engineering for retrofit when requirement change

* Service Contracts

* Operating and Maintenance training


Macawber operates worldwide with manafacturing bases in the USA, China, India, Brazil, and UK. Customer support is available via  representatives and associates.We partner extensively with OEM’s and engineering house sharing our expertise and adding value to their scope of work.

P1728 Denseveyorcleaned




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Macawber has been awarded a substantial contract for conveying EAF Dust for a steel mill located in Arkansas. The order includes 28 Ashveyor systems and is expected to be in operation early 2016.


Ashveyor Pneumatic Conveying

Ashveyor Pneumatic Conveying

The Ashveyor is an ash conveying system for ESP and Baghouse ash handling needs.  It is widely used for conveying various types of ash such as fly ash, bed ash, bottom ash, biomass ash, EFA dust, sinter dust and others.   Small equipment footprint is ideal for low headroom applications and retrofit requirements. Designed to operate as a multiple-vessel system on one conveying line and suitable for high temperature applications. The Ashveyor is unique to combustion industry and its reliability and efficiency has been proven in thousands of installations worldwide.

Ash Conveying Systems Brochure (pdf)

Watch a Video:

Key Features:

  • Multiple feed points on one conveying line, ideal for ESP or baghouse applications.
  • Dust-less, fully enclosed system eliminates dust spillage. Environmentally responsible.
  • Efficient and simple controls; system operates on demand only.
  • 10 ESP feed points can be handled on just one conveying line. Dramatically reduces piping requirements.
  • All ash and combustion by-products can be handled; coal ash, BIOMASS ash, steel smelter dust ash.
Typical flow diagram layout of simple single 4 vessel ESP field.

Typical flow diagram layout of simple single 4 vessel ESP field.

Ash Conveying Systems for Baghouse and ESP

Ash Conveying Systems

Ash Conveying Systems


Ashveyor Pneumatic Conveyors in a Line

Ashveyor Pneumatic Conveyors in a Line


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We are pleased to announce a publication in the May issue of Powder and Bulk Engineering Magazine. The article written by our John Bell and titled “Pneumatically conveying fragile materials without particle degradation” focuses on discussing extensively the concept of conveying fragile materials and how to design an efficient, reliable and cost effective conveying system that minimises material degradation.  Macawber has excelled in dense-phase pneumatic conveying for over 40 years specializing in difficult to handle materials such as pet food, peanuts,  sugar, fish food, seeds, raisins, corn and others.  Below is a link to John’s article:

Pneumatically conveying fragile materials without particle degradation


Please contact us at the link below to inquire about our products and services:

Contact Macawber Engineering, Inc. | Pneumatic Conveying Systems | Macawber

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AIChE is the world’s leading organization for chemical engineering professionals, with over 45,000 members from over 100 countries.

Founded in 1908, the American Institute of Chemical Engineers (AIChE) is a nonprofit organization providing leadership to the chemical engineering profession representing 45,000 members in industry, academia, and government.

By the invitation of Tom Maddox of T.L. Maddox, our very own Joel Swieringa had the honor of being a presenting speaker at the 2015 April meeting , held at the Engineers’ Club of Saint Louis, together with members of the AMSE. Joel gave a presentation on the “Fundamentals of  Dense Phase Pneumatic Conveying”. This presentation covered the theory of operations and the fundamentals of dense phase conveying, advantages and features of the various types of equipment, and selection of the best equipment for various applications. Dense phase low velocity is well suited to handle problematic materials like ash, EAF Dust, sugar, sand, fish food pellets, rice puffs, lime, cullet, cement and others.  The benefits of dense-phase conveying include increased operating efficiency and reduced maintenance costs.  All very important issues when designing a system to fit your unique requirements.

Macawber is an expert in dense-phase pneumatic conveying, having focused on this process for over 40 years. The company continues to provide solutions to customer specific material handling requirements and appreciated the opportunity to share their know-how and experience with a attentive group of mechanical engineers.Thank you Joel for a job well done.

Here is a link to the event


For inquiries about our services follow the link below:

Contact Macawber Engineering, Inc. | Pneumatic Conveying Systems | Macawber

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Dense phase pneumatic conveying is best described as using the lowest attainable material velocities to ensure the majority of material remains below the saltation level. It is a simple, efficient, cost-effective and safe mode of transport particularly beneficial for handling difficult to convey materials.

What are the benefits of dense phase pneumatic conveying ?

* Low air/energy Consumption (cyclical and autonomous functionality)

* Minimal material degradation

* Minimal material segregation

* Low pipeline and component wear

* Fewer maintenance points

* Capable of handling abrasive materials

* Capable of handling fragile materials

* Environmentally friendly; no material spillage, no dust emission, low noise emission

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To find out more please contact us

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Aerated Bulk Density is the ratio of material mass to volume when the material has been aerated.  Note that some materials do not aerate.  It is often necessary to aerate the material within the feed hopper to ensure that it enters the vessel and to aid conveying.  Since the conveying rate is determined by the volume of material transferred within a particular time, knowledge of the aerated bulk density is vital to enable us to correctly size a system.

Read the full article…

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Read the full article…

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The flow rate must be accurate and controllable. The Controlveyor provides the following: Read the full article…

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Check out our new ad! Capture
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System loaded on transport vehicle

System loaded on transport vehicle

The Macawber Macpump T150, a single system, but with two vessels. As one is conveying the other is filling and preparing to convey. The pneumatic conveying distance is 2955ft horizontal and 65ft vertical conveying over 100t/h of crushed limestone. The convey line starts at 12” and finishes at 14”. This was a challenging application due mainly to the limestone material being out of specification relative to the initial sample upon which the system was designed. However, with a few small modifications and careful optimizing the system achieved all the customer’s specifications and is now working 24 hours per day 7 days a week at a power station. Batch size and sequence control is by two sets of load cells with system control selectable either from the central control room via Ethernet communication protocols or at the local panel.

Read the full article…

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Pneumatic Conveying

Pneumatic Conveying

First of all decide what kind of pneumatic conveying regime is required – dilute phase or dense phase. Dilute phase relies on a high air flow to maintain the material particles in a suspended condition. With chunky material the velocity to achieve complete suspension is extraordinary high and not very practical. So dense phase conveying, which does not rely on a high velocity for conveying is a better choice.

Dense phase systems operate at high pressure – anywhere from 20 to 50 psig depending on distance and other factors. This requires the use of a pressure vessel to introduce the material into the conveying line.  With lumpy sticky material, the choice of vessel type is critical. These kinds of material tend to bridge easily in silos and hoppers – the same goes for pressure vessels. So to avoid bridging or jamming in the vessel discharge a small compact vessel with steep sides and a large transition between the vessel discharge and pipe line is essential.

Read the full article…

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Vessel After Painting

Vessel After Painting

Two Macawber Fly Ash Systems were supplied to convey 30t/h each over a distance of up to 1,265ft horizontal and 121ft vertical. The ash systems use 40 cu.ft. vessels with a 6” pipe line. Both conveying systems are located under a feed hopper with start and stop controlled in automatic by the feed hopper and silo reception level probes. The Fly Ash systems are working very reliably with no line blockages and exceed the customer’s expectation regarding transfer rate and performance. These particular Macawber systems incorporated multiple manifold settings allowing the transfer of a range of Fly Ash products over various distances. The final convey air requirement on the longest route was 760scfm compared to the proposed 988scfm resulting in a saving both in cost and air used from the compressed air system. One particular problem was a very low control air pressure resulting in a compromised sealing of the Dome filling valve inflatable seal. This was overcome by installing a pressure doubler and small air reservoir to provide more than sufficient instrument air pressure and excellent sealing.

Read the full article…

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WG Denseveyor conveying malted barley

Denseveyor conveying malted barley

The Denseveyor is a low velocity dense-phase pneumatic conveying system using here a single pressure vessel to cyclically transfer 10T/hour Malted Barley for 280 ft as it is made available by gravity feed to the machine. The Denseveyor is filled by gravity through the special Dome® Valve and when the vessel is choke filled the valve closes through the material and seals closed to a pressure differential of 7 barg. The conveying air is applied to the pressure vessel in a special controlled method that allows the material to pass down the pipeline at a low velocity reducing material degradation.


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Power station boiler building - system 3

Power station boiler building – system 3

Three Macawber dense-phase pneumatic conveying systems were supplied to convey bed ash between 5t/h for the two smaller conveying systems and 56t/h for the larger system 3. Material transfer distances are between 158ft and 230ft. The ash systems use 2 x 4 cu.ft. vessels with 4” pipe lines and system 3 uses an 30 cu.ft. vessel on a 10” pipe line. All dense-phase systems are located under feed hoppers with start and stop controlled in automatic by the feed hopper and silo reception level probes to maintain empty feed hoppers and full reception silos. System 1 is used on the Economizer line with a water cooled top plate and dome filling component to withstand the high temperatures. System 2 and 3 are standard in that no additional equipment is required to handle high temperature up to 390°F material temperature. Other Ashveyor equipment supplied were switch type diverter valves, isolation high temperature knife gate valves, wear resistant bends and end diverters placed on top of the reception silos. System 3 conveyed the ash material directly in to the fluid bed of the boiler.

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The three systems ready for delivery.

The Three Systems Ready For Delivery


Three dense-phase, low velocity pneumatic conveying systems were supplied to convey coal dust between 1.5t/h and 2.7t/h over a distance of 525ft horizontal and 30ft vertical. The systems were 2 x 3ft3 and a single 8 ft3 vessel all with a 3” convey pipe line. All pneumatic conveyors are located under a feed hopper with start and stop controlled automatically by the feed hopper and silo reception level probes. The material handling systems are working very reliably with no line blockages and exceed the customer’s expectation regarding transfer rate giving 2.9t/h for the smaller systems and 5.9t/h for the large system 1. The pipe line conveying pressure was between 8psi and 12.5psi. Convey air requirement was substantially less than that proposed at 88scfm and 180scfm. The proposed air requirement was 176scfm and 278scfm. The systems are pneumatic only to the ATEX equivalent of Eexd Class II Division 2. The customer elected to control the systems through their own high level PLC and DCS systems.

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Mixed Mortar Conveying System

Mixed Mortar Conveying System

The low velocity dense-phase pneumatic conveying system supplied conveys in 90t/h of mixed mortar over a distance of 360ft horizontal and 115ft vertical. The system uses a 52 cu.ft. vessel with a 8” pipe line. The system is located under a mixer which in turn is fed by multiple product feed hoppers. The starting and stopping sequence of the system is controlled  automatically from a central control room via an Ethernet connection. The pneumatic conveyors are working very reliably and exceed the customer’s expectations regarding rate transferring over 130t/h. The system incorporated multiple manifold settings allowing the transfer of a wide range of bulk materials and sizes. The system set-up is done automatically simply by selecting the material recipe. Further options have been added since the initial start-up including a four way diverter valve and the addition of more reception silos and conveying lines. The end user is extremely satisfied with the system and the flexibility it offers considering the hundreds of different mixes that need to be conveyed.

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pneumatic conveying of fish food pellets

Pneumatic Conveying of Fish Food Pellets

Two dense-phase pneumatic conveying systems were supplied to handle 35 tons per hour of Fish Food Pellets over a distance of 265 feet horizontal and 90 feet vertical. The systems were 30 cubic foot vessels with a 10 inch pipe line. Both systems were located under a feed hopper with start and stop controlled in automatic mode by the feed hopper and silo reception level probes.

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We are the original designers and patent holders for the world famous Dome Valve.


Inflatek Valve cutaway copy transparent

Inflatek Valve cutaway copy transparent

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