2018 RETA Breeze May- June

EDUcATION

Dissecting Industrial Refrigeration: Book 1 Round 1 L i n e ar Me a s u r eme n t s

by Sarah Selzer, Safety Services Jr. Safety Engineer, Wagner-Meinert LLC

is article contains excerpts from RETA’s Industrial Refrigeration Book 1. e reader should take care when applying the knowledge gained from reading this material in their speci c plant. It is important to consider cause and e ect when making any adjustments to facility operating conditions. Refrigeration has been used by mankind since ancient times. A solid foundation makes operations much easier. Basic math skills, a knowledge of measurements, and a knowledge of how to apply and interpret measurements is one of the fundamental skills all operators should acquire. RETA’s Industrial Refrigeration: Book 1 provides the knowledge necessary to develop these fundamental skills Many students become concerned about the math portion of the text. Math is fundamental. I believe people who have been out of school for an extended period get apprehensive because of the word math. My grandfather was a welder fabricator his entire life. He quit school in the eighth grade but laid out blanks and did advanced math his entire life. e secret was, he didn’t think of it as math. A typical day in the fabrication shop would start something like this. 1. We need to price hard facing plow shears for a six bottom John Deere plow with 16” shears. We charged 80 cents per inch of weld. is may seem like math, but grandpa would take the pencil from behind his ear and write 6 x 16 x$.80 = $ 76.80, but he didn’t consider this math he called it “ gurin”. He was good at “ gurin”, but not good at math. Many times, there would be calculations scribbled across the walls of the fabrication shop. “We need to make 20 sti ners, each sti ner is a “Half square” (triangle) with a 4” base”. Sheets came 8” x 6’. So how many sheets would we need? More “ gurin”.

A sheet would make 4 sti ners (2 triangles 4” long and 2 more turned upside down) per row so we needed 1 sheet (20/4 = 5 rows, 5 rows x 4” = 20”) much shorter than the 6’ sheet. So how many could we make from the sheet? 6’x12” per foot = 72” Each row of 4 would take 4” so 72 / 4 = 18 rows. 18 rows x4 per row = 72 sti ners. is assumed no waste or that the waste could be absorbed by the tolerance on the size of the sti ners. e point is, grandpa did complex math every day in the shop and we do too. ere should be no fear of the math in book 1. Pages 1-6 through 1-9 discuss measurements. Length is a straight-line dimension. When we measure lumber, we measure length. Closely related to length is width, also a straight-line dimension. Usually length is the long dimension

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