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Engineering
Consulting
Services For Industrial Furnaces, Kilns, Ovens, and Production Processes
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Richard
B. Conway, CMfgT
Industrial
and Systems Engineer
Ceramic
Engineering Technician
Heat
Processing Technician
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Author
unknown - but probably a pretty good engineer.
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“We just call him Doctor
Oven.”
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Sam Hopkins, Engineer,
United States Marine, Inc.
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"Richard
Conway applied science to our oven issues and helped us to improve
operational reliability and reduce down time through quality services
and effective solutions."
Mark Docter, Production
Supervisor
BALL
CORPORATION
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Consulting
Services Provided:
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Engineering analysis and
problem solving services performed personally by Richard B. Conway,
President of DELTA H SYSTEMS, INC.;
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Analysis of furnace, kiln,
and/or oven system designs to resolve production defects, modifications
to enhance output, or to improve operation; and,
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Design services for new
product or processes.
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Representation:
During a
consulting project, Mr. Conway strictly represents the interest of the
client. DELTA H will not bid on any phase of a recommended
solution.
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Problem Solving Methodologies:
Typically,
a three phased classical engineering problem solving methodology is
used involving: problem identification, generating feasible
alternatives, and selection and implementation of the most practical
alternative. Often 70% to 90% of a project is dedicated to
identifying the real problem. Once a problem is stated with
scientifically defensible data the solutions for repair are often
simplistic and obvious.
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Background and Experience:
Richard
Conway offers a unique combination of industrial and educational
experiences to assist manufacturing firms in solving thermal processing
system and production problems. In addition to training in
several technical disciplines, Mr. Conway has studied creative problem
solving methodologies and logic at university level. Successful
projects have involved heat treating and atmosphere controls, to
ceramic and materials drying and firing, to facility level economic
analysis of production alternatives. Mr. Conway's educational
background includes a Bachelor of Science Degree in Industrial and
Systems Engineering, Associate of Applied Science Degrees in both
Ceramic Engineering Technology and Heat Processing Technology, and
specialized training in military aviation electronics. Mr. Conway
is a Certified Manufacturing Technologist (CMfgT) by the Society of
Manufacturing Engineers and is a Certified Service Representative (CSR)
of DESPATCH INDUSTRIES. Work experience and past employers
included: U.S. Air Force, AP Green Refractories, Hotwork, Inc., North American Manufacturing
Company, Pereny Equipment Company (now
Unique/Pereny Kilns), Brimstone Equipment
Company, and Accutherm, Inc. In 1990, Mr. Conway founded DELTA H
SYSTEMS, INC. while attending classes at The Ohio State University
(OSU) as a returning adult student. Upon graduating from OSU in
1993, Mr. Conway continued developing and growing DELTA H into a
successful business with over 300 clients to date.
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Professional Affiliations and
Associations:
The
American Ceramic Society, Ceramic Manufacturer's Association, Society
of Manufacturing Engineers, Association of Finishing Processes of SME,
Institute of Industrial Engineers, American Society for Metals
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Technical
Mysteries with Thermal Processing:
Test you
analytical skills with an actual recent project. Check this web
page periodically for new challenges!
Initial
Problem Description:
The client
produces over 30 million small propane cylinders per year.
Occasionally the cylinders fail a pressure check or have clogged valves
and, upon inspection, a "cobweb like" material is observed
inside. This problem has been known for nearly 40 years and has
become more prominent to a level that it must be addressed.
Analysis
and Observations:
The
following was observed upon inspecting and testing the system:
- Four furnaces are used for
the production process - all are atmosphere roller hearth types with 3'
by 3' baskets for the placing the cylinders vertically, a high heat
section and long cooling sections.
- The cylinders are
manufactured by several stamping processes and the sections and valves
are held together by brazing.
- Braze for holding the two
halves together is applied by a centrifuge device which "spins" braze
on.
- The basic process involves
brazing and bright annealing of low carbon steel to manufacture the
cylinders.
- Dew point sampling of the
atmosphere suggested no problems with the exothermic gas atmosphere.
- There has been no observed
correlation of the problem with any one of the four furnaces.
- An operator stated that
whenever there is a failure of a cylinder they always find the cobweb
like substance inside.
- Upon obtaining a sample of
the cobweb substance it was observed that it was magnetic.
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What was the Problem?
- When the cylinders enter the
furnace they have air inside of them.
- The brazing material which
seals the upper and lower halves of the cylinders must have some excess
braze inside of the cylinder which acts as a "getter" for oxygen.
As the cylinders heat up the organic binders in the braze act as a
getter when they quickly burn to remove oxygen before any iron oxide
(rust) forms.
- If there was insufficient
braze, and therefore insufficient organic materials inside of a
cylinder, then iron oxide would form along the inside walls.
- As the hydrogen component
(~15%) of the exothermic atmosphere would later diffuse into the
cylinder, it would reduce the iron oxide back to pure iron
(magnetic).
- The reduced iron oxide (pure
iron) was the observed mysterious cobweb material.
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Formal Problem Statement:
The
centrifuge device which spins braze materials inside of the cylinder
for connection of the upper and lower halves, experiences occasional
variations in the consistency of the application of the braze
material. When insufficient material is applied then iron oxide
will form which is later reduced back to iron by the furnace
atmosphere. The reduced iron oxide has a cobweb like appearance
and accounts for clogging of valves and would have a secondary
characteristic of a poor seal of the two cylinder halves.
Selected
Feasible Alternative for Repair:
The client
focused their attention of the mechanical functions of the braze spinning device and modified it to
provide more consistent application of braze material. Upon the
completion of the modification of the spinning device the problem was
no longer observed.
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