Experts

Compressors

Royce Brown, principal, RNB Engineering

Dr. Merherwan P. Boyce is chairman of the Boyce Consultancy Group in Houston. He has more than 35 years of experience in the field of turbomachinery and has been a pioneer in optimization of such equipment, including on-line real-time performance monitoring at chemical plants, refineries and other installations.

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Compressor efficiency
If I have four air reciprocating compressors in a series, what would happen to the efficiency if I placed them in parallel to each other?
Category: Compressors

Compressed air applications
I was curious to know where can we use high pressure process air. I am trying to understand the applications of compressed air above 150 psig. The only applications that comes to mind is the manufacture of pet bottles. Are there any other applications or industries where compressed air above 150 psig is used?
Category: Compressors

Air receiver size for reciprocating air compressor
How can we determine the size/capacity of an air receiver for a reciprocating air compressor? What are the factors that affect the capacity of receiver?
Category: Compressors

Centrifugal compressor surging phenomenon
Please describe the surging phenomenon with a centrifugal compressor. We use a MHI compressor that is turbine driven. How should we take action?
Category: Compressors

Speed definitions
Kindly tell me, what is the difference between rated speed, design speed and normal speed of a compressor? What is the significance of maximum continuous speed?
Category: Compressors

Effect of natural gas, molecular weight
What is the effect of natural gas and molecular weight on the head and power consumption of a centrifugal compressor?
Category: Compressors

General compressor information
Is it essential to measure the viscosity of the refrigerant/oil mixture or lube during operation? Is there a minimum viscosity that is required to prevent damage to the bearing and other components? Where can I learn about the different types of compressors?
Category: Compressors

Parallel compressor correlation
I need to run a test on two parallel compressors to see if they can give a global output of a given flow and pressure. Can I accurately correlate the results if I test the compressors one at a time?
Category: Compressors

Head loss calculations
How can we calculate the head loss due to various bends in a reciprocating compressor? Will the cfm increase substantially by reducing bends? How to reduce the bends and fittings?
Category: Compressors

Finding a specific brand manufacturer
We are trying to find the manufacturer of ChemTherm branded products. It is a trademarked product, but an Internet doesn’t lead to anything. We know it was used in the late 1990's and still may be today. Any suggestions as to the manufacturer?
Category: Compressors

Bar conversion in compressed air systems
In a compressed air system, what cfm at 6 bar would translate to 80 cfm at 1 bar using a pressure reducing valve?
Category: Compressors

Centrifugal compressor speed
What is the effect on the pressure change when the centrifugal compressor speed is to be increased? Are there ways we can increase the efficiency of a multi-staged compressor other than using interstage cooler?
Category: Compressors

Compressed pressure losses
What is role of pipe bends in compressed pressure losses?
Category: Compressors

Calculate discharge pressure
I have the complete data sheet of a compressor that compresses hydrogen from pressure P1 to P2. How do I calculate the discharge pressure if I compress nitrogen of pressure P3 by the same compressor? Will the result vary for centrifugal and reciprocating machines? If so, how?
Category: Compressors

Ammonia storage tank compressor
I need compressor(s) for an ammonia storage tank. The NH3 gas from tank has about 18,000 kg/hr at 1.03 Barab. and -25ºC (at compressor inlet). Required discharged pressure is about 16.0 Barab. Normally I use oil filled screw compressors, but due to the high flow rate can I use a centrifugal type as well? Do you expect power saving if we use centrifugal type compared with screw type?
Category: Compressors

Portable gas compressors
We are currently working on an project where there is generation of methane/biogas at positive pressures. There is the need to compress and bottle the gas in cylinders for transport and use. Are there portable compressors available for compressing the gas and filling the same to cylinders?
Category: Compressors

Purpose of motor relief valves
We have a two-stage, electric-motor-driven, rotary screw compressor at our facility. There are relief valves installed after the low-pressure compressor element and after the high-pressure compressor element. What is the purpose of the relief valves, or what would cause over-pressure to occur? Are they sized based on the compressor capacity?
Category: Compressors

Is there any setting in a two-stage blower that can influence the output pressure?
We have a two stage combustion air blower with backward inclined vanes.The rated output flow is 3900 cubic mtr/hr and the output pressure is 1300 mm of WG.At present the output pressure is not going above 750mm of WG.We have checked for leakages as well as for obstrution but found none. Is there any setting in the blower that can influence the output pressure?
Category: Compressors

Is there any relationship between the pipeline size and compressor rating in scm?
To select compressors for pipeline filling and drying during commissioning operations, is there any relationship between the pipeline size and compressor rating in scm?
Category: Compressors

Determining ratio compression
How do you determine ratio compression?
Category: Compressors

Importance of anti-surge control systems
What's the importance of an anti-surge control system in centrifugal compressors?
Category: Compressors

Finding a supplier for a difficult order
I have several chemical manufacturing sites have a need for a compressor requiring the following specifications. The molecular weight of the gas is 18.0 and is saturated H2O vapor with trace (50 ppm) concentration of hydrogen peroxide. Flow rate = 11,562 kg / hr Inlet temperature = 47oC Inlet pressure = 80 mm Hg absolute Relative humidity = 100% Discharge pressure = 456 mm Hg absolute Cooling water temperature = 30 oC Ultimately, we will require three units. Unfortunately, I cannot find an interested supplier in the U.S. and a European colleague cannot find an interested supplier in Europe. How can I obtain these machines and if I find a supplier willing, how can I ensure high quality, timely delivery, and longterm reliability?
Category: Compressors

Protecting from overloading your compressor
If I am running three gas compressors in parallel and one of the compressors fails, the load will be increased on the other compressor, how do I protect from overload?
Category: Compressors

Using back-to-back casings
Why use back to back casings?
Category: Compressors

Relationship between temperature and pressure in gas compression
What is the relationship between temperature and pressure in gas compression?
Category: Compressors

Centrifugal compressor control
What are the basics of two-stage centrifugal compressor control?
Category: Compressors