How the startup technician works with your employees

About the startup technician. Typically, the startup technician for a new pneumatic conveying system is an employee of the system supplier. (In some cases, the supplier may provide a team of startup technicians.) The technician’s services can be contracted on a day-by-day basis or can be included as part of a turnkey system package.

The technician’s responsibilities. The startup technician’s work begins long before your pneumatic conveying system is ready to start up. In fact, this expert should be on-site during the system’s installation in your plant. Participation during this stage not only gives the startup technician experience in the intricacies of your particular system, but gives the technician an opportunity to notice potential trouble spots and prevent them from leading to conveying problems later on. Then the technician will return for actual startup, which can take less than 1 day for a simple conveying system and up to 1 week for a more complex system.

Plant employee responsibilities. Responsibility for a successful system startup doesn’t rest solely with the startup technician. Even when you use the technician’s services, plant employees still play the most critical roles in ensuring that the system starts up successfully and then continues to run as it should. All plant employees responsible for the system’s operation and maintenance, particularly the system operator and maintenance worker, should be present at startup as part of becoming fully trained to run and troubleshoot the conveying system.

Preparing for startup

Since most training for the employees who will operate and maintain your pneumatic conveying system will occur during system startup, it’s important to lay some training groundwork ahead of time. Start by arranging to relieve the system operator and maintenance worker of other duties during the startup period so they don’t have to run off to handle other projects or take calls; such interruptions will disrupt the training and prevent the employees from learning valuable information.

Also give the employees copies of the system drawings and the operations and maintenance manual provided by the supplier so they can become familiar with these materials and the conveying system before the system is started up. Familiarity with the manual will make it easier for the employees to consult it when questions or problems arise after startup is over.

Component lubrication is always your company’s responsibility — and specifically that of the system operator and maintenance worker — not the supplier’s.

The final step in preparing for startup is make sure that all conveying system components that require lubrication, such as air movers (blowers, fans, and compressors), rotary airlock valves, and valve lubricators, are filled with oil as outlined in the operations and maintenance manual. Component lubrication is always your company’s responsibility — and specifically that of the system operator and maintenance worker — not the supplier’s. Ensuring that your employees study and follow lubrication procedures described in the manual will prevent annoying system breakdowns and lengthy battles down the road over who will pay for the cooked blower or other component damaged by insufficient or improper lubrication.

Initiating the startup

Before arriving at your plant, the startup technician will develop a procedure for starting up your pneumatic conveying system. This procedure will be based on specific details the technician has learned about your system during installation, as well as on the technician’s hands-on experience with many previous conveying system startups. The procedure will cover two basic stages: running the system with air only (called a dry run) and then running it with both air and material. Plant employees should fully participate in both stages to ensure that they receive the detailed training they need to operate and troubleshoot the system.

First stage. The first stage is a chance to be sure that all conveying system components are functioning properly before material is fed into the system. The procedure for this stage will typically look something like this:

1. Before starting up the system, check that those system components requiring lubrication have been properly lubricated. Then thoroughly check over the entire system to be sure that all components are properly hooked up. Are the electrical wires connected properly? Is the conveying piping configured correctly and connected with all bolts properly tightened? Also check that the bag or cartridge filters in each bin vent dust collector or filter-receiver have been installed correctly. Now activate the system’s “On” switch to start up the system with air only, with no material entering the system.

2. Check the orientation and rotation direction of all air movers, motors, and rotary airlock valves. Are these components oriented and turning in the right direction

Material Diverter Bin vents

A professional startup technician can ensure that your pneumatic conveying system is successfully initiated by checking the installation and function of system components and monitoring the system’s performance.

to provide the required vacuum or pressure or material feed? It’s not uncommon for air movers to be wired incorrectly, causing them to move air in the wrong direction. Also check that air is flowing through the conveying line in the proper direction.

1. Check that all other valves, such as diverter, butterfly, and knife-gate valves, are working. Check that each valve is correctly positioned during each conveying cycle, and determine whether each valve will be correctly positioned when you begin running material through the system.
2. Ensure that all scales or load cells in the conveying system have been properly set, zeroed out, and check-weighed.
3. Turn the conveying system off and run it again with air only another two, three, or more times until the system performance has good repeatability. The more destinations the system delivers to, the more runs it may take to achieve this.

Successfully completing the steps in this first stage will ensure that everything in the conveying system is working right — the air mover isn’t reversed, each valve is operating, and the airflow through the system is set properly — so that the system won’t plug when you start running material through it.

Second stage. After the system is turned on for the second startup stage and the material begins to feed through the rotary airlock (or other) valve, the startup technician makes several system checks and adjustments. This procedure typically includes these steps:

1. Check all valves for proper operation. Is each rotary air-lock, diverter, butterfly, knife-gate, or other valve feeding or directing the flow of material in the direction of the conveying airflow? Is each pressure relief valve functioning correctly?
2. Check all vents, including bin vents and rotary valve leakage vents. Is each vent clear and working correctly?
3. Check each bin vent or filter-receiver to be sure it’s working properly. This includes checking the Magnehelic gauge to determine the pressure drop across the filters and checking for dust in the exhaust.
4. Set the timers for conveying and cleaning cycles. Check these items: Is the material feeding smoothly to the system? Is the material feeding at the correct rate and moving at the desired rate through the system? As you check the system vacuum or pressure gauges, does the vacuum or pressure remain consistent, without varying more than one or two units? Are the conveying cycles starting and stopping at the right time? Are the filter-cleaning cycles set properly? Are the filters properly cleaned during each cycle — that is, does the cleaning cycle maintain the proper pressure drop across the filters according to the Magnehelic gauge?
5. Check that the conveying system is delivering the correct amount of material, such as by reading weight data from the scale under a supply hopper or receiving vessel or using other data.
6. Check that the diverter, butterfly, knife-gate, and similar valves are opening and closing as they should throughout each conveying cycle.

Make sure that the conveying system is properly set up before running any material through it.

Before the startup technician leaves

Now that the startup has been completed successfully and your pneumatic conveying system is up and running properly, the startup technician will provide one more important service: reviewing the entire operations and maintenance manual with the system operator, maintenance worker, and other plant employees to ensure that every part of the system’s operation has been covered. Now is a good time for employees to ask the startup technician any remaining questions on how to run and troubleshoot the system.

As part of this final training, the startup technician will provide several important pointers:

• Make sure that the conveying system is properly set up before running any material through it. This includes checking most of the items in the procedure for the first startup stage.
• If the conveying system goes down, find the root cause of the problem (or problems), fix it, and, before resuming normal operation, take the time to evaluate the entire system for other problems that may have resulted from the initial problem.
• Think of the conveying system’s operations and maintenance manual as your best friend: Refer to it often.

At this point, you may also hire the startup technician to stay on to provide further system operation and performance monitoring — especially if the system will convey multiple materials at several rates — or to provide further training.

Enlisting the services of a professional startup technician is a practical way to protect your pneumatic conveying system investment. Your biggest reward? A conveying system that runs smoothly under the supervision of employees who have the skills to operate and troubleshoot the system. PBE

For further reading

Find more information on pneumatic conveying system startup and related topics in articles listed under “Pneumatic conveying” in Powder and Bulk Engineering‘s comprehensive article index at www.powderbulk.com and in the December 2007 issue.

G. Barry Slater is president of ALL-CON World Systems, PO Box 647, Seaford, DE 19973; 302-628-3380, fax 302628-3390 (bslater@all-con.com, www.all-con.com). Peter Wypych is director of the Key Centre for Bulk Solids & Particulate Technologies at the University of Wollongong, New South Wales, Australia (+61-2-4221-3488, fax +61-2-4221-4577, peter_wypych@uow.edu.au).

Tel.: +1-302 628-3380

Emal: sales@all-con.com