Refrigeration - Frederick M. Jones

Refrigeration & Fred McKinley Jones

Refrigeration is a process of moving heat from one location to another in controlled conditions.

 

A refrigerator uses the evaporation of a liquid to absorb heat. It's all based on the following physics: - a liquid is rapidly vaporized (through lowering compression) - the quickly expanding vapor requires kinetic energy and draws the energy needed from the immediate area - which loses energy and becomes cooler. Cooling caused by the rapid expansion of gases is the primary means of refrigeration today. The liquid, or refrigerant, used in a refrigerator evaporates at an extremely low temperature, creating freezing temperatures inside the refrigerator.

The History

 

The history of artificial refrigeration began when Scottish professor William Cullen designed a small refrigerating machine in 1755. Cullen used a pump to create a partial vacuum over a container of diethyl ether, (C2H5)2O which then boiled, absorbing heat from the surrounding air. The experiment even created a small amount of ice. Though a method had been discovered for cooling substances it was not commercially practical at the time and no widespread processes had been invented.

 

During the early 1800s, consumers preserved their food by storing food and ice purchased from ice harvesters in iceboxes. The technology did not progress but iceboxes were used until nearly 1910.

 

In 1911, GE released a household refrigeration unit that was powered by gas. The use of gas eliminated the need for motor and decreased the size of the refrigerator. However, electric companies that were customers of GE did not benefit from a gas-powered unit. Thus, GE invested in developing an electric model. In 1927, GE released the Monitor Top, the first refrigerator to run off electricity.

 

In 1930, Frigidaire, one of GE’s main competitors, synthesized Freon (CF2Cl2). With the invention of synthetic refrigerants, safer refrigerators were possible for home and consumer use. In the 1970s, though, the compounds were found to be reacting with atmospheric ozone, an important protection against solar ultraviolet radiation, and their use as a refrigerant worldwide was curtailed in 1987.

Current Applications

 

Probably the most widely used current applications of refrigeration are for air conditioning of private homes and public buildings, and refrigerating foodstuffs in homes, restaurants and large storage warehouses. The use of refrigerators in kitchens for storing fruits and vegetables has allowed adding fresh salads to the modern diet year round, and storing fish and meats safely for long periods. Optimum temperature range for perishable food storage is 37 - 41 °Fahrenheit (3 to 5 °Celsius/Center grade).

 

Dairy products are constantly in need of refrigeration, and it was only discovered in the past few decades that eggs needed to be refrigerated during shipment rather than waiting to be refrigerated after arrival at the grocery store. Meats, poultry and fish all must be kept in climate-controlled environments before being sold. Refrigeration also helps keep fruits and vegetables edible longer.

 

Cyclic Refrigeration

 

Heat naturally flows from hot to cold. To make a refrigerator function, you must reverse this natural process and make heat flow to heat and cold flow to cold. This is physically impossible to do directly. In order to make a refrigerator work, the system has two separate components one in which heat flows to cool in the exterior of the system and make heat flow to cool ion the interior part of the system.

 

The difference between them is that on the exterior part of the system, the temperature of the heat source is much higher than in the interior part of the system which you are trying to keep cool.

 

This consists of a refrigeration cycle, where heat is removed from a low-temperature space or source and rejected to a high-temperature location with the help of external work.

 

A refrigeration cycle describes the changes that take place in the refrigerant as it alternately absorbs and rejects heat as it circulates through a refrigerator. It is also applied to heating, ventilation, and air conditioning HVACR (Heat-Ventilation-Air Conditioning-Refrigeration) work, when describing the "process" of refrigerant flow through an HVACR unit.

Work is applied to cool a living space or storage volume by pumping heat from a lower temperature heat source into a higher temperature heat location. Insulation is used to reduce the work and energy needed to achieve and maintain a lower temperature in the cooled space.

The vapor-compression cycle is used in most household refrigerators as well as in many large commercial and industrial refrigeration systems.

 

The Vapor-Compression System

 

In the refrigeration cycle, there are five basic components: fluid refrigerant; a compressor, which controls the flow of refrigerant; the condenser coils (on the outside of the fridge); the evaporator coils (on the inside of the fridge); and something called an expansion device. Here’s how they interact to cool your food.

  1. The compressor constricts the refrigerant vapor, raising its pressure, and pushes it into the coils on the outside of the refrigerator.

  2. When the hot gas in the coils meets the cooler air temperature of the kitchen, it becomes a liquid.

  3. Now in liquid form at high pressure, the refrigerant cools down as it flows into the coils inside the freezer and the fridge.

  4. The refrigerant absorbs the heat inside the fridge, cooling down the air.

  5. Last, the refrigerant evaporates to a gas, and then flows back to the compressor, where the cycle starts all over.

 

People in cities are heavily dependent upon remote locations in order to obtain their food for daily consumption. How to get that food there without it spoiling was a problem.

 

…and then along came Jones

 

Frederick McKinley Jones was born in Cincinnati, Ohio on May 17, 1893. At an early age, Fred demonstrated a great interest in mechanical things, whether taking apart a toy, a watch or a kitchen appliance. Eventually he became interested in automobiles.

 

At the age of twelve, he began working sweeping up at a garage. He spent much of his time observing the mechanics, and that, along with an appetite for learning through reading developed within Fred an incredible base of knowledge about automobiles.

 

In 1912, at the age of 19, Jones moved to Hallock, Minnesota, where he worked as a mechanic.

 

On August 1, 1918 Jones enlisted in the 809 Pioneer Infantry of the United States Army and served in France during World War I. While serving, Jones recruited German prisoners of war and rewired his camp for electricity, telephone and telegraph service.

 

In 1919, Fred returned to Hallock.

 

Over the next few years Fred began tinkering with almost everything. When one of the doctors he worked for on occasion complained that he wished he did not have to wait for patient to come into his office for x-ray exams, Jones created a portable x-ray machine that could be taken to the patient. Unfortunately, like many of his early inventions, Jones never thought to apply for a patent for machine.

 

In 1927, Jones was faced with the problem of helping friend convert their silent movie theater into a “talkie” theater. Not only did he convert scrap metal into the parts necessary to deliver a soundtrack to the video, he also devised ways to stabilize and improve the picture quality. When Joe Numero, the head of Ultraphone Sound Systems heard about Fred’s devices, he invited Fred to come to Minneapolis for a job interview.

Despite the fact the company's receptionist reportedly told 38-year old Jones on arrival for the interview that "We don't have any jobs for a colored boy," Numero offered Jones a job as an electrical engineer.

 

Around 1935, Jones designed a portable air-cooling unit for trucks carrying perishable food. Before Jones' invention, the only way to keep food cool in trucks was to load them with ice.

 

In 1938 a golfing buddy of Numero's complained of problems his business was experiencing with heat-related loss of perishables during transport. To Numero's surprise, the friend later brought a truck to Ultraphone, challenging Numero and his engineers-one of whom was Fred Jones-to create a refrigerated truck. Later that year, Jones and Numero co-founded the U.S. Thermo Control Company of Minneapolis, later known as Thermo King.

 

Jones was given the task of developing a device that would allow large trucks to transport perishable products without spoiling. Jones set to work and his automatic refrigeration system, and transformed the shipping and grocery businesses.

 

This landmark invention ushered in the era of frozen foods, large supermarkets and the restaurant industry as we know it today. Refrigerated transport also made the delivery of fresh produce anywhere in the country a possibility, regardless of the season. The concept of continuous cooling of perishables is often referred to as the "Farm to Fork" cold chain.

 

In 1938, Numero founded a new venture: the U.S. Thermo Control Company (later to become Thermo King). Jones served as vice president of engineering. One year later, Jones filed for Thermo Control’s first patent: the Model A, the world’s first successful system for refrigerated transportation.

 

1939 - Around this time, Fred came up with a new idea – an automatic ticket-dispensing machine to be used at movie theaters. Fred applied for and received a patent for this device in June of 1939 and the patent rights were eventually sold to RCA.

 

The Model A. developed in 1939 was designed to be mounted onto the undersides of semi-trucks and to pass refrigerant tubing to their trailers. The Model A worked, but it was heavy and bulky.

 

The real breakthrough came with the Model C. The refrigeration unit was placed at the front top of the trailer where it remains to this day.

During World War II, Thermo King made Model Cs exclusively for the U.S. military. The military applied the invention to boats, planes, and trucks in order to transport temperature-sensitive drugs and blood plasma to soldiers in need.

 

The Model C became commercially available after World War II and immediately made an impact on the agricultural industry. Jones’ invention laid the groundwork for the modern supermarket.

 

1944 - Jones became the first African American to be elected into the American Society of Refrigeration Engineers.

 

 

1948 - Building on existing technology, Thermo King developed refrigerated box cars for use in rail transport.

 

1949 - Thermo King was a $3 million business.

During the 1950s he was a consultant to the U.S. Department of Defense and the Bureau of Standards.

 

1956 - Thermo King air conditioning units are installed in passenger buses.

 

1958 - Thermo King incorporated diesel engines into refrigerated units.

 

February 21, 1961 - Frederick McKinley Jones passed away.

 

During his life, Jones was awarded 61 patents. Forty were for refrigeration equipment, while others went for portable X-ray machines, sound equipment, and gasoline engines.

 

Patents (partial list)

•         U.S. Patent 2,163,754 was issued on June 27, 1939 – Ticket dispensing machine.

•         U.S. Patent D-132,182 was issued on April 28, 1942 – Design for air conditioning unit.

•         U.S. Patent 2,336,735 was issued on December 14, 1943 – Removable cooling units for compartments.

•         U.S. Patent 2,337,164 was issued on December 21, 1943 – Means for automatically stopping and starting gas engines.

•         U.S. Patent 2,475,841 was issued on July 12, 1949 – Automatic refrigeration system for long-haul trucks.

•         U.S. Patent 2,477,377 was issued on July 26, 1949 – Means for thermostatically operating gas engines.

•         U.S. Patent 2,509,099 was issued on May 23, 1950 – System for controlling operation of refrigeration units.

•         U.S. Patent D-159,209 was issued on July 4, 1950 – Design for air conditioning unit.

•         U.S. Patent 2,523,273 was issued on September 26, 1950 – Engine actuated ventilating system.

•         U.S. Patent 2,526,874 was issued on October 24, 1950 – Apparatus for heating or cooling atmosphere within an enclosure.

•         U.S. Patent 2,535,682 was issued on December 26, 1950 – Prefabricated refrigerator construction.

•         U.S. Patent 2,780,923 was issued on February 12, 1957 – Method and means for preserving perishable foodstuffs in transit.

 

Later in 1961 Mr. Numero sold the company, which had 3,000 employees worldwide and was based in Bloomington, Minn., to the Westinghouse Electric Corporation. He continued as its president until 1963 and was honorary chairman until his death.

 

May 10, 1991— Joseph A. Numero passed away.

 

September 16, 1991 - President George Bush, Sr. posthumously awarded Jones and Numero with the National Medal of Technology.

 

In 1996 - Thermo King had revenue of $996 million and earnings of $141 million.

 

1997 - Ingersoll Rand a diversified industrial equipment manufacturer acquired Thermo King from Westinghouse.

 

2017 – Though actual figures were not available to this author, Thermo King is most likely a billion dollar company.

 

Refrigeration Problem Set (examples)

1. If the number  of the temperature of the melting point of a refrigerant in Fahrenheit is lower than it is in centigrade how can the number of the temperature of the boiling point be  higher in Fahrenheit?,

 

Refrigerant :          Melting point     −103.3 °C (−153.9 °F)

                              Boiling point       −26.3 °C (−15.3 °F)

 

The unit of measure is not the same size in each scale. In order to convert Celsius/Centigrade a temperature to Fahrenheit the following conversion formula must be applied; C = 5/9 (F-32).

 

2. A refrigerator produces 400 units of heat and removes 200 units of heat from inside the refrigerator. How much heat must it dispel into to its surroundings?

 

The refrigerator must reject an amount of heat to the room equal to the sum of the heat produced by the refrigerator and the heat removed from its contents or 400 units of heat + 200 units of heat = 600 units of heat.

 

3. A fifty foot coil of 3/8 inch copper tubing weighs 9.9 lbs. How much does one foot weigh in ounces (round to a tenth of an ounce)?

(9.9/50) X 16 = 3.17 ounces

 

4. The efficiency of a heat engine is defined as the ratio of the work done by the engine to the heat supplied. A heat engine takes in 900 units of heat from a high temperature and and produces 300 units of work in each cycle. What is its efficiency expressed as a percentage?

 

                              X = W/QH                             X = 300/900        33%

 

5. A British thermal unit (BTU) is a measurement of heat. It is the amount of energy or heat required to raise the temperature of one pound of water one degree Fahrenheit.

 

When water freezes or melts at a temperature of 32 degrees Fahrenheit. The heat requirement for the change of state between ice and water is 143.4 BTUs. When water reaches the boiling point at 212 degrees Fahrenheit and turns to steam, the required amount of BTUs for the change of state is 970.3 BTUs.

6. How many BTUs must be lost (dissipated), to cool a pound (lb)of water from 50 degrees to 49 degrees?

One BTU.

 

7. How many BTUs must be dissipated to turn a volume of steam that will condense into a pound (lb) of water at 212 degrees Fahrenheit? Assume the steam has a temperature of 215 degrees Fahrenheit.

3 +970.3 BTUs =  973.3 BTUs

 

8. A gallon of water weighs 8.3 pounds (lbs). If a gallon of water is to be turned into ice and the initial temperature of the water is 50 degrees Fahrenheit and the temperature of the ice is assumed to 30 degrees Fahrenheit. How many BTUs will the refrigerating system have to dissipate to produce the ice?

8.3(18+143.4+2) = 1,356.2 BTUs (rounded to tenths)

 

9. A typical refrigerant Tetrafluoroethane (CH2FCF3) has a Heat of Vaporization (the amount of energy required to change from liquid to gas) of 93.4 BTU. Assuming a pound of refrigerant is in a vapor-condensation cooling system and has a 75% efficiency level. Efficiency being how much of the transition work being done by the system is brought to bear on the target, while the other amount is lost(dissipated) in the working of the process.

 

If this refrigerant is turn a gallon of water initially at 35 degrees Fahrenheit into a block of ice at 30 degrees Fahrenheit how many complete cycles (round the nearest whole cycle above your calculation) will it take for the refrigerant to produce the block of ice?

 

93.4 BTUs x 0.75 = 70.05 BTU per cycle

 

8.3 (3+143.4+2) = 1,231.72 BTUs / 70.05 = 17.583 or 18 cycles

For any questions, please contact David Trotman :

415-298-8979

1519 O'farrell St. San Francisco, CA 94115