On this Day:
On May 20, 1892 George Sampson patented the clothes dryer. But any claims that he invented the clothes dryer are all wet.
We take them for granted now, but clothes dryers are a fairly recent invention. In 1955, only 10 percent of U.S.households had one, probably because they were expensive. Back then, the average price for a dryer was $230. Adjusted to year-2000 dollars, that lowly laundry appliance would have cost $1,600. Forty years later, the average dryer costs about $340.
The earliest clothes dryers were made in England and France in the late 18th and early 19th centuries. Known as “ventilators,” they were large metal drums with ventilation holes, powered by hand cranks, and used over open fires. Their invention can’t be traced to any one person, but perhaps no one would have wanted the credit, since the clothes always smelled of smoke, were often covered with soot and sometimes caught fire.
First Patented Clothes Dryer
An American inventor, George T. Sampson of Dayton, Ohio, came up with a better ventilator-type dryer. It had a rack and used heat from a stove, rather than an open fire. He was granted a patent for his invention in on June 7, 1892.
First Electric Dryer
Inventor J. Ross Moore lived on a North Dakota farm in the early 20th century. Tired of hanging wet clothes outside in the frigid winters, he built a shed, installed a stove and hung the clothes there to dry. Over the next 30 years, Moore developed his idea for an automatic clothes dryer. He finally built a drum-type model that worked. He developed both gas and electric models but, due to financial difficulties, needed to find a manufacturer to produce them. After many rejections, he struck a deal with Hamilton Manufacturing Company of Two Rivers, Wis. Hamilton began selling the new automatic clothes dryer, named the “June Day,” in 1938.
The Growing Market
Dryers grew in popularity during the 1940s. Following World War II, Hamilton Manufacturing and the newer entrants into the clothes-dryer market, like GE, were selling over 60,000 gas and electric dryers annually. In 1955, Whirlpool began marketing a gas dryer with the claim that it took half the time to dry the clothes as regular-speed dryers, because of increased air flow and gas output.
In 1946, dryer manufacturers moved controls to the front of the dryer, added a timer, an exhaust for moist air, temperature controls and a cool-down cycle. In 1958, a 30-inch-wide dryer using a negative pressure system was first offered to the public. This system is still used in dryers. In 1959, dryness-sensors were first used to shut off the power when the load was dry. In 1965, dryers with permanent-press cycles were introduced. In 1972, manufacturers put electric starters on gas dryers. In 1974, microelectronic controls were put on dryers to time drying cycles. In 1983, the first clothes dryers with delayed start timers allowed users to run dryers in off-peak hours. In 1985, clothes dryers were offered with all-Spanish instructions on labels, consoles and manuals. Other models offered large type, big graphics and over-sized controls. (per https://www.theclassroom.com/the-history-of-the-clothes-dryer-13410374.html)
But minds have been tumbling in the clothes-drying world; keeping patent lawyers busy with their inventions of new ways of drying clothes:
These centrifuge machines simply spin their drums much faster than a typical washer could, in order to extract additional water from the load. They may remove more water in two minutes than a heated tumbler dryer can in twenty, thus saving significant amounts of time and energy. Although spinning alone will not completely dry clothing, this additional step saves a worthwhile amount of time and energy for large laundry operations such as those of hospitals.
Just as in a tumble dryer, condenser or condensation dryers pass heated air through the load. However, instead of exhausting this air, the dryer uses a heat exchanger to cool the air and condense the water vapor into either a drain pipe or a collection tank. The drier air is run through the loop again. The heat exchanger typically uses ambient air as its coolant, therefore the heat produced by the dryer will go into the immediate surroundings instead of the outside, increasing the room temperature. In some designs, cold water is used in the heat exchanger, eliminating this heating, but requiring increased water usage.
In terms of energy use, condenser dryers typically require around 2 kilowatt hours (kW⋅h) of energy per average load.
Because the heat exchange process simply cools the internal air using ambient air (or cold water in some cases), it will not dry the air in the internal loop to as low a level of humidity as typical fresh, ambient air. As a consequence of the increased humidity of the air used to dry the load, this type of dryer requires somewhat more time than a tumble dryer. Condenser dryers are a particularly attractive option where long, intricate ducting would be required to vent the dryer.
Heat pump dryers
A closed-cycle heat pump clothes dryer uses a heat pump to dehumidify the processing air. Such dryers typically use under half the energy per load of a condenser dryer.
Whereas condensation dryers use a passive heat exchanger cooled by ambient air, these dryers use a heat pump. The hot, humid air from the tumbler is passed through a heat pump where the cold side condenses the water vapor into either a drain pipe or a collection tank and the hot side reheats the air afterward for re-use. In this way not only does the dryer avoid the need for ducting, but it also conserves much of its heat within the dryer instead of exhausting it into the surroundings. Heat pump dryers can, therefore, use up to 50% less energy required by either condensation or conventional electric dryers. Heat pump dryers use about 1 kW⋅h of energy to dry an average load instead of 2 kW⋅h for a condenser dryer, or from 3 to 9 kW⋅h, for a conventional electric dryer. Domestic heat pump dryers are designed to work in typical ambient temperatures from 5 to 30 °C. Below 5 °C, drying times significantly increase.
As with condensation dryers, the heat exchanger will not dry the internal air to as low a level of humidity as the typical ambient air. With respect to ambient air, the higher humidity of the air used to dry the clothes has the effect of increasing drying times; however, because heat pump dryers conserve much of the heat of the air they use, the already-hot air can be cycled more quickly, possibly leading to shorter drying times than tumble dryers, depending on the model.
Mechanical steam compression dryers
A new type of dryer in development, these machines are a more advanced version of heat pump dryers. Instead of using hot air to dry the clothing, mechanical steam compression dryers use water recovered from the clothing in the form of steam. First, the tumbler and its contents are heated to 100 °C. The wet steam that results purges the system of air and is the only remaining atmosphere in the tumbler.
As wet steam exits the tumbler, it is mechanically compressed (hence the name) to extract water vapor and transfer the heat of vaporization to the remaining gaseous steam. This pressurized, gaseous steam is then allowed to expand, and is superheated before being injected back into the tumbler where its heat causes more water to vaporize from the clothing, creating more wet steam and restarting the cycle.
Like heat pump dryers, mechanical steam compression dryers recycle much of the heat used to dry the clothes, and they operate in a very similar range of efficiency as heat pump dryers. Both types can be over twice as efficient as conventional tumble dryers. The considerably higher temperatures used in mechanical steam compression dryers result in drying times on the order of half as long as those of heat pump dryers.
Marketed by some manufacturers as a “static clothes drying technique”, convectant dryers simply consist of a heating unit at the bottom, a vertical chamber, and a vent at top. The unit heats air at the bottom, reducing its relative humidity, and the natural tendency of hot air to rise brings this low-humidity air into contact with the clothes. This design is slow, but relatively energy-efficient. It is only marginally faster than line-drying.
Solar clothes dryer
The solar dryer is a box-shaped stationary construction which encloses a second compartment where the clothes are held. It uses the sun’s heat without direct sunlight reaching the clothes. Alternatively, a solar heating box may be used to heat air that is driven through a conventional tumbler dryer.
Japanese manufacturers have developed highly efficient clothes dryers that use microwave radiation to dry the clothes (though a vast majority of Japanese air dry their laundry). Most of the drying is done using microwaves to evaporate the water, but the final drying is done by convection heating, to avoid problems of arcing with metal pieces in the laundry. There are a number of advantages: shorter drying times (25% less), energy savings (17–25% less), and lower drying temperatures. Some analysts think that the arcing and fabric damage is a factor preventing microwave dryers from being developed for the US market.
Ultrasonic dryers use high-frequency signals to drive piezoelectric actuators in order to mechanically shake the clothes, releasing water in the form of a mist which is then removed from the drum. They have the potential to significantly cut energy consumption while needing only one-third of the time needed by a conventional electric dryer for a given load. They also do not have the same issues related with lint in most other types of dryers.
Some manufacturers, like LG Electronics and Whirlpool, have introduced hybrid dryers, that offer the user the option of using either a heat pump or a traditional electric heating element for drying the user’s clothes. Hybrid dryers can also use a heat pump and a heating element at the same time to dry clothes faster. (per Wikipedia).
First, a Story:
I thought my clothes dryer was shrinking my clothes.
Turns out, it was my refrigerator…
Second, a Song:
Jordan Page, creator of “FunCheapOrFree” has a video on YouTube.com that explains her unconventional laundry hacks, tips and tricks. She states:
“It may be unconventional, but it works! Here’s how I do my laundry!
Get even more of my laundry tips at: http://funcheaporfree.com/laundry” We hope you enjoy this!
Thought for the Day:
“Normal is getting dressed in clothes that you buy for work, driving through traffic in a car that you are still paying for, in order to get to a job that you need so you can pay for the clothes, car and the house that you leave empty all day in order to afford to live in it.” – Ellen Goodman
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Have a great day!
Dave & Colleen
© 2022 David J. Bilinsky and Colleen E. Bilinsky