TECHFLOW is proudly one of the manufacturing pioneers of the Dense Phase Conveying Systems aka the Pneumatic Transporters, Foundry Transporter, & Material Transporter. Techflow Conveying System uses compressed air to convey the materials from the source location to different locations. The Source location is single while delivery location might me multiple. As compared to the LEAN Phase Systems, Dense Phase Conveying uses high pressured air to convey bulk or powder material through closed pipe and deliver to the collection points

The solids movement style in the piper categorizes the Dense Phase Pneumatic Conveying Systems in to 2 types, namely - Continuous Type & Plug Type.

Dense Phase Conveying use dry compressed air as the primary moving force since this type of conveying demands medium to high pressure.

The Velocities for conveying are designed to be relatively low as compared to Lean Phase Conveying due to high volume of material and stays under 5 mtr/sec. The starting pressure, however, surpass the designed pressure with the system resistance and to be conveyed distances by 3 to 4 Bar. The pipes are designed as per the throughput requirement which results it in being relatively smaller.

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What is Dense Phase Conveying?

Mechanical Conveying Equipment conventionally handle Granular, Solid, & Powdered Materials using equipment like bucket elevators, conveyers, good lifts, screw conveyers, etc.

Taking help of inert gas or air travelling through a closed pipeline, the new concept is able to transform airborne solids into a fluid state. Over the past 3 decades, as a result to how attractive the market has found this concept thanks to a closed pipeline conveying, the idea has been accepted and appreciated by most industries in order to handle solids pneumatically.

At the design stage, pressure and air volume is applied to the product depending on its characteristics. The systems due to the parameters, are then categorized into either DILUTE / LEAN Phase Conveying System or the DENSE Phase Conveying System.

TECHFLOW supplies following type of Dense Phase Pneumatic Conveying Systems.

Empty Pipe Conveying System
Full Pipe Conveying System

The Difference : Pneumatic Conveying vs Mechanical Conveying

Material Conveying	Easy routing due to higher degree of flexibility	Difficult due to rigid mechanical component and lines
Spillage	No spillage due to sealed pipes	Heavy material loss due to open surface conveying
Floor to Space Area	Less due to adaptability to take up facility’s dimensions	Higher due to volumetric components
Efficiency	High	Moderate
Safety	Safer as material is sealed	Hazardous due to risk of spillage during the conveying
Material Health	Free from atmospheric moisture: suitable for air sensitive products like e.g. sugar	Risk of contamination
Maintenance	Less moving parts makes easy to maintain	Large moving parts causes high and frequent maintenance
Abrasion	Minimized due to use of wear resistant bends	No such design

Working of Dense Phase Conveying System

In order to transport & receive the powder material, there is a pressure vessel placed between the collection and delivery point. The size of pressure vessel depends on the overall conveying capacity of conveying system

One Primary feed hopper is place over the pressure vessel which works as a reservoir and receives the powder or bulk material either manually or through some feeding system. A pulse jet vent filter is placed on the receiver or delivery silo to push out the compressed air to atmosphere from conveying cycle.

To achieve full automation, Pressure vessel, silo and feed hopper all are equipped with level sensor. A electrical panel with PLC programme controls the valves and other eqipmnents and efficiently operates the Filling and Conveying cycles.

1. Filling Cycle

It is the filling process of powder material e.g. fine sand, Dust, Bentonite to the pressure vessel through dedicated feed hopper. The flow control valves e.g. knife gate valve, dome tuff are kept open and material is filled into vessel until the level sensor signals PLC to stop to achieve high level.

2. Conveying Cycle

After successful conveying the dome tuff and knife gate valves are closed and after dwelling period Air Valve is opened. Air valve supplies the high pressure dry air that pushes the conveying material till the silo. When the pressure vessel indicates the low level PLC closes ends the conveying cycle. The pressured air is extracted from delivery silo through the vent filter and only material is remained in silo.

Applications

Dense Phase Conveying
Alumina Bag House Dust Barlite Bentonite Conveying Clay Calcium Carbonate	Ash Corn starch Cement Clinker Diatomaceous Earth Fluorspar Gypsum	Lime Perlite Salt Sand Soda Ash Food Powder	Carbon Black Application Foundry Sand Manganese Ore

Schematics

Dense Phase Conveying

Advantages of Dense Phase Conveying :

Very small installation space / foot print is required to install the vessel.
Same requirement of Power/Operating cost as compared to other means of Transfers.
Less breakdown incidences & single point Maintenance plus low wear & tear of the conveying parts.
No need of any Dust Collection systems.
Elimination of major civil works / Foundations etc
Low conveying velocities in the pipe line - thus less wear & tear problems.
Small sized vent filters due to low amount of airflow involved as compared to lean phase systems.
Suitable even in complex plant layouts.
Higher conveying distances are possible as compared to Mechanical transfer.
Closed loop system - thus eliminating dusting.
Facilitate transfer the solid from single / Multiple Feeding Points to very long distances & multiple locations.