Coal Prep Slurry Pumps Impeller Adjustment

OTP Industrial Solutions for Pump Applications
Written by Carl Gable
October 22, 2009

Coal slurry pumps are essential part of the mineral processing in a coal prep plant.   A common problem in these plants is keeping the impeller properly adjusted as the parts wear.  Improper impeller adjustment results in premature wear to the liquid end of the pump, and can affect the efficiency and performance of the entire system.

However, impeller adjustment can be a dreaded job for a mechanic.  The atmospheric corrosion present in most prep plants often causes the bearing assemblies to seize to the pedestal, and the adjusting mechanisms to become inoperable.

CoalPrep

Recently a customer voiced his concerns about this problem. We listened and presented the customer with a customized solution.

The customer agreed and purchased a new pedestal that was sent directly to our Middletown Ohio pump repair facility. We machined the pedestal to accept new removable 316ss seats, while maintaining tolerances. (The stainless seats will not seize to the cast iron bearing housing).  We then manufactured and installed a new design adjuster mechanism to allow the mechanic to adjust the impeller from the rear of the pump – making adjusting faster, easier and safer.

The coal prep customer is pleased and OTP is in the process of upgrading other plants’ slurry pumps as well.

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Omron Industrial Automation Authorizes OTP in Ohio

COLUMBUS, OHIO – October 21, 2009 – Ohio Transmission & Pump (OTP) announced today that Omron Industrial Automation has authorized OTP in most counties in the state of Ohio.

“We are excited about our new partnership with Omron and look forward to helping our customers with Omron’s incredibly powerful, yet easy to implement industrial automation products,” states Bob Korb, Vice President of Sales. “In addition to our significant investment in product training for all technical sales associates, we also have hired seven experienced electrical and automation specialists to fully and immediately support this exciting product line.”

Omron Industrial Automation provides a complete line of industrial automation products, including PLC, HMI, AC drive, servo drive, servo motor, sensor, vision sensing, power supply, pushbutton and indicator products.

The OTP website has been expanded to include full support for Omron Industrial Automation.  The unique “Ask the OTP Experts” on-line functionality enables the user to easily find technical information about Omron products, and to quickly obtain specific answers to their automation questions.

About OTP:

For almost five decades, OTP has merged the knowledge, talent and passion of its associates with a complete lineup of the industry’s best manufacturers to deliver the solutions that help industrial customers achieve their goals.  OTP delivers innovative technical solutions for industrial fluid power, pump, mechanical power transmission and electrical applications.

OTP and its sister company Air Technologies® operate 16 locations with over 300 associates serving industrial customers in Ohio, Indiana, Illinois, Kentucky, West Virginia, Pennsylvania, Michigan, Texas, Alabama and Georgia

Contact:
Jack A Grote
Chief Operating Officer

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Variable Frequency Drives (VFD) Power Loss Ride Through

OTP Industrial Solutions for Electrical Applications
Written by Tim Griffith
October 22, 2009

lightningVariable Frequency Drives (VFD) are commonly used in industrial applications. However, the sensitive components of VFD’s are often susceptible to Power Loss, Power Dips and Brown-Out conditions, which may cause the VFD and the entire system to shut down.

Fortunately there are several solutions for power interruptions. Some VFD manufacturers have incorporated specific algorithms in the software and, with just a few programming changes, the VFD can withstand most of these conditions.

Recently a customer contacted me about a power loss condition which was causing his VFD to drop out.  His VFD (which controls his air compressor) had to be restarted each time by issuing a start command separate from the machine it was controlling.  The customer asked me if there was anything that I could do to allow his drive to stay powered up during a Power Loss lasting up to three seconds.

Depending on the manufacturer and model of the VFD – and its programming – the drive can store the energy from its capacitor banks for a predetermined amount of time before dropping out and losing power.  Think of it this way; if you turn off a VFD, the lights remain on for a few seconds before it is totally powered down.  The software can utilize this stored energy to maintain the VFD through a short intermittent Power Loss.

Furthermore, the good news for my customer was that even if it is a long Power Loss, I showed him how to program a second set of parameters in a VFD to restart automatically.  Note: starting automatically needs to be analyzed for safety first before programming that function)

I helped my customer reprogram his drive, and his VFD (and his air compressor) is now able to “ride-through” intermittent power losses.

Moral of this story: There are many features available in most VFDs…and I can help you take advantage of these features.

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OTP Releases “Ask the OTP Experts” Web Functionality

October 5, 2009

COLUMBUS, OHIO – October 5, 2009 –Ohio Transmission & Pump (OTP) announced today that the company has released the innovative “Ask the OTP Experts” web functionality.

“We designed our website to help the user quickly find the important technical information about the broad selection of products that we support and sell,” states Jack A Grote, Chief Operating Officer. “Even more importantly, we make it simple for the user to connect to an OTP expert to get the personal answers that he wants – even if he doesn’t have time to explore the website.”

“Ask the OTP Experts” enables the user to easily obtain the answers to technical questions about the industrial products from over 60 different manufacturers.

About OTP:

For almost five decades, OTP has merged the knowledge, talent and passion of our associates with a complete lineup of the industry’s best manufacturers to deliver valuable and innovative solutions that help industrial customers achieve their goals. OTP delivers innovative technical solutions for industrial fluid power, pump, mechanical power transmission and electrical applications.

OTP and its sister company Air Technologies® operate 16 locations with over 300 associates serving industrial customers in Ohio, Indiana, Illinois, Kentucky, West Virginia, Pennsylvania, Michigan, Texas, Alabama and Georgia.

Contact:

Jack A Grote
(614) 342-6123
jgrote@otpnet.com

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C-130 Aircraft Starter Gearmotor

OTP Industrial Solutions for Electrical Applications
Written by Woody Schmetzer
September 21, 2009

My outside salesperson called me and said he had a new customer who wanted help sizing up a gear drive. This sounded simple enough….probably just another drive for a conveyor or something common like that. I run into these kind of applications every day.

So when I spoke to the customer and found out he needed a 1.5hp gearmotor for a starter generator for a C130 plane, I was excited at the opportunity and the challenge. He was unsure of which style or design he needed, but did have one requirement that it had to be rated for at least 500 ft-lbs of output torque.

Like most new applications, I sized up with a gearmotor in two different styles (inline and right-angle) and also threw in a third option which would allow him to go down to a 1hp and save him a few hundred dollars.

The customer ended up liking the in-line gearmotor, and now I’m waiting for a purchase order. Just another day in the office!

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Quarry Pumps with Excessive Vibration

OTP Industrial Solutions for Pump Repair
Written by Tom Bland
September 15, 2009

quarry-pumpsWe received a call from a large stone quarry requesting a budget quote to rebuild a 200 HP, 4-stage vertical turbine pump used for quarry dewatering. We visited the site to review the installation and to gather additional information as to the nature of the problem. While driving deep into the quarry, the site manager explained that these pumps were mounted ten feet above the normal high level and would draw down to 23 feet to the minimum level. The pumps are also mounted on a mezzanine-like structure. This high mounting distance, and the mezzanine mounting was necessary to prevent flooding of the motors should the quarry lose power or experience an abnormally heavy rainfall.

As we climbed the stairs to the top of the structure, the excessive vibration became very evident. In fact, the whole structure had such severe vibration that we questioned the ability of the welds and fasteners to keep it together!

Although the pumps were clearly causing excessive vibration, we decided to confirm the pumps were correctly sized for the job before we assumed that a rebuild was required.

After gathering the necessary information including the pump discharge pressure of 70 psi and the distance from the gauge to the water level, we then compared the actual operating conditions against the design conditions.

The design condition was 2200 gpm at 250 feet of head with a requirement of 34 feet of net positive suction head (NPSH).

Calculated NPSH available:
33 ft. atmospheric pressure
– 1 ft. vapor pressure at 75F
+ 3 ft. minimum submergence of bowl assembly at low level cut-off
——————
35 ft. NPSH available

The NPSH available is barely sufficient for the design condition requirement of 34 feet, but more than ample for higher water levels. But is the pump operating at design condition?

70 psi discharge pressure x 2.31 = 162 ft. head
Distance from gauge to low water level = 23 ft.
Operating condition 185 ft. head

Referring to the pump curve, at 185 ft. hd. this pump will deliver 2600 gpm with 50 ft. of NPSH required! The NPSH required (50 ft.) exceeds the NPSH available (35 ft.) by 15 ft.

At run-out, or maximum flow, of 2860 gpm at 141 ft. head, this pump requires 72 ft. of NPSH. It was clear that cavitation was the cause of the vibration.

Returning to the pump, we throttled the discharge valve to return the pump to the original design condition and as expected, the vibration disappeared. This unit also operates in parallel with additional pumps. When all three pumps are running, the total discharge head (TDH) is sufficient to restrict the flow and keep the pump near the original design point. But operation of this pump alone or with only one additional pump will always require close monitoring and throttling to prevent excessive wear or failure due to cavitation.

By reviewing the installation prior to removal, we prevented an unnecessary rebuild on this VTP pump.

Proper selection of all design conditions is critical to correct pump selection. In this real world example, the VTP pump supplier did not consider that the pump may be operated beyond the design condition. In fact most pumps operate outside of their design condition as they are typically oversized for worst case conditions.

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As the industry experts on bearings, OTP hosts this blog to share our own insights—and to invite our customers and other industry professionals to offer ideas, comments and perspective as well. We’re glad to have you as part of our online bearings community, and we look forward to your contributions.

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As the industry experts in mechanical power transmission, OTP hosts this blog to share our own insights—and to invite our customers and other industry professionals to offer ideas, comments and perspective as well. We’re glad to have you as part of our online motion control community, and we look forward to your contributions.

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As the industry experts in fluid power, OTP hosts this blog to share our own insights—and to invite our customers and other industry professionals to offer ideas, comments and perspective as well. We’re glad to have you as part of our online fluid power community, and we look forward to your contributions.