Clothes dryer#Spin dryers

A spin dryer (also laundry centrifuge ) is a home appliance in barrel shape, which is used to pre-dry wet textiles using the centrifugal force machine.

Development

Not only the hand washing of textiles, but also the subsequent wringing was a work which stressed the strong arm muscles of the washerwomen, but also the fabric of the garments to the late 19th century. We completed this first exclusively by hand and later with a wringer or laundry press. The wringer consists of two rubber rollers between which the linen was pressed. The wringer was either, later operated electrically with muscle strength and partially attached to the washing machine. In the laundry press, similar to a fruit press, the wet laundry items were combined and thereby forced out by lowering a piston down the water.

Much easier was the removal of water using the first spin dryers that had emerged around 1900 and initially operate even without motor support by hand. Are thanks two people for the necessary drive.

In the 1930s the first electric clothes dryers came on the market. They had a very low volume capacity and yet have no lockable lid. But the machine had a base of solid iron, the who with the great mass that the spin did not begin to wander. The problem was solved by a resilient mounting of the drum and counterweights made ​​of steel or concrete. The machines were now closed, which was a substantial improvement in the security because the start-up was possible in part only with closed lid. The opening of the cover is often automatically connected to the braking of the drum. Easier Clothes dryers are manually braked with a pedal.

Function

A spin dryer is designed in such a way to free the still wet from washing washing of water that they at best is still damp later. However, spin refers to the entire process of turning when washing. In the cylindrical, high tonne, the laundry is in the opening is filled up, and the inner and seventh drum is rotated at a high revolution number. By the resulting centrifugal forces in the rotation, the laundry is pressed against the drum wall and dewatered thereby. The water enters here from out of the laundry and can leave the perforated drum. The bottom of the side of the outer shell is an outlet through which the water drains.

Among the occurring forces see the example in the article centrifugal force.

History

In the early 1960s had around 27 % of households in the former West Germany a spin dryer. After the introduction of fully automatic washing machines, which are also able to offer a spin cycle after the wash program, lost the clothes-dryers in importance and have disappeared almost completely from the market.

Efficiency

In view of saving energy, the spin dryer but has still a right to exist. As more and more households practicing the machine drying, the use of a spin dryer is highly recommended, when the spin speed of the washing machine is below 1,000 rpm. But even still spin at outputs up to 1,500 revolutions per minute ( 1/min ), the residual moisture of the laundry to be reduced by another. The speed performance of a spin dryer varies between 1.400 1/min 2,800 1/min to 3600 1/min. However, the speed is only meaningful in conjunction with the drum diameter. The diameter of the rotating speed is quadratic, but only linear in the spin centrifugal force = centrifugal efficiency one. At the same speed a 60 - cm - drum therefore is twice as efficient as a 30- inch drum. But rises with the same drum diameter, the speed of 1,400 to 2,800 1/min 1/min, the spin effect increased to 4 times the value.

The energy requirement is substantially lower than in an electric dryer at a spin dryer. This requires a much greater expenditure of energy at longer time to dry the remaining moisture. Also for allergy sufferers who are sensitive to detergents and fabric softeners, the use of a spin dryer can make a positive impact, because detergent residues are removed with the residual water from the laundry.