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Clothes dryer solution
Clothes dryers, also known as household clothes dryers, are a very common application in household appliances. Dryers can be divided into industrial and civilian. Industrial dryers are also called drying equipment or dryers. Civilian dryers are one of washing machines. They are generally used to remove clothing and other textiles after washing and dehydration. of moisture.
With the fast pace of urban life and the improvement of living standards. For families living in cities, a dryer is becoming more and more necessary. It helps everyone to wear dry and comfortable clothes in winter or rainy weather. Although a simple clothes dryer is a very simple and cheap household equipment, the price ranges from tens of yuan to one or two hundred yuan; but because of its safety, convenience and easy storage, it has been widely used, and it is widely used in e-commerce. Many sellers on the website also have thousands of sales. The process of drying clothes is a physical process involving many aspects such as convection diffusion, water evaporation, fluid heat transfer and so on. Research in these areas also has practical significance.
1. The structure of the clothes dryer
Common portable clothes dryers on the market are composed of a main unit, a clothes rack and a sealed cloth cover.
The host is composed of an inner filter, a fan and a PTC heating element. The main engine is installed at the lower position of the clothes drying rack, and the air inlet of the main engine has a certain space from the ground. After the clothes are hung on the clothes hanger, the airtight cloth cover is covered on the clothes hanger, and the air outlet of the main machine is located at the bottom of the airtight cloth cover. The top of the airtight cloth cover has an air outlet.
2.The drying principle of the clothes dryer
The fabric to be dried is mainly composed of fabric fibers (cotton fibers in this case) and moisture. At the beginning of drying, the main machine provides dry hot air, on the one hand, the temperature of the fabric to be dried is raised, and on the other hand, the dry hot air takes away the moisture on the surface of the fabric. Due to the evaporation of surface moisture, a humidity difference is created between the surface and the interior of the fabric. Driven by this humidity difference, the moisture inside will diffuse towards the surface.
Through the simulation of various physical phenomena in the drying process of the clothes dryer, we can understand the process of drying clothes more intuitively. The temperature, wind speed and the moisture contained in the clothes interact with each other, so that the moisture content in different parts of the clothes changes at different speeds.
For manufacturers of simple clothes dryers, how to make the dry hot air from the air inlet as uniform as possible sent from the bottom is the key to improving the drying efficiency. A large amount of ineffective dry hot air is lost through the path of least resistance. In terms of design, appropriately adding a circuitous path or adding a diffuser at the air inlet can make the hot air as uniform as possible.
For families who have already purchased a simple clothes dryer, it is the best choice to put the most difficult to dry clothes in the place closest to the air inlet. At the same time, consider how to arrange the clothes so that the clothes do not hinder the flow of air as much as possible.
3. Which one is better, the washing and drying machine or the clothes dryer?
After entering March, the weather in the south gradually becomes humid. After washing clothes, it becomes more difficult to let them air dry. At this time, a household clothes dryer is very useful. But in the face of all-in-one washing and drying machines and clothes dryers in the market, which one is the product that is really suitable for entering the family? What is the essential difference between them?
1. From the perspective of the occupied area
Even though the domestic housing prices have stabilized slightly recently, they are still at the level of every inch of land. Especially the design of many bathrooms, the washing machine can't fit, let alone the extra clothes dryer.
At this time, the space occupied by the all-in-one washing machine has obvious advantages compared with the combination of "washing machine + clothes dryer". However, many clothes dryers that are matched with washing machines can be stacked up and down with special brackets. Therefore, for families with no height restrictions, there is not much difference in floor space between a stand-alone clothes dryer and an all-in-one washing and drying machine.
2. From the perspective of volume
The volume unit of the washing machine is kilograms, which is often referred to as kilograms. As a clothes dryer that is matched with the washing machine, the capacity is also measured in kilograms. For general washing and drying machines, the rated weight of laundry and the rated capacity of drying are not the same. Taking entry-level products as an example, for products with a rated capacity of about 8kg, the rated capacity for drying is about 4kg or 5kg. What effect does this have? Just put a pile of dirty clothes in at one time. Although they can be washed clean at one time, they are not completely dried and still damp. And using a washing machine to wash sheets, quilt covers, curtains, etc., cannot be completely dried to a level that can be used directly. As for the stand-alone clothes dryer, the rated capacity is usually larger. Therefore, most people feel that the all-in-one washing and drying machine can’t dry, but the stand-alone product is no problem. In fact, if you buy a high-end all-in-one washing and drying machine, the rated drying capacity will also increase, and the effect is no worse than that of an independent one.
3. From experience
In fact, the user experience can be viewed from several angles, such as drying speed, drying effect, cumbersomeness, and the wrinkle of dried clothes.
(1) In terms of speed, both are very slow. A single drying basically takes more than 2 hours, and a washing takes about half an hour.
(2) In terms of drying effect, the problem of rated capacity will cause the middle and low-end all-in-one washing and drying machines to fail to dry clothes completely. High-end products and independent products are better, but the price of high-end washing and drying machines is relatively high.
(3) From the perspective of cumbersomeness, it is definitely better to use an all-in-one washing and drying machine. After all, throw dirty clothes in and shake them out before wearing them.
(4) In terms of the folds of clothes, independent products are more dominant. But in fact, this is not the cause of the model. Since the clothes will be strongly compressed during the drying stage, the fibers of the clothes will be bent and shaped when they are directly dried. The independent clothes dryer has a process of taking it out of the washing machine and shaking it. During this process, the fibers of the clothes are relatively flat, and they will not be too wrinkled after drying. However, after washing the all-in-one washing machine, take it out and shake it off, and then throw it back into the washing machine to dry again to achieve a similar effect. In addition, most all-in-one washing and drying machines do not have a lint collector. If the lint accumulates in the washing machine and is affected by high humidity and high temperature, it is prone to mildew. Most independent clothes dryers will have a lint collector.
4. From the perspective of price
The price of the mainstream 8kg domestic clothes dryer is around 4,000-6,000 yuan, the price of the mainstream 8kg washing machine is around 3,000-4,000 yuan, and the total price of the two is around 7,000-10,000 yuan. The price of an 8kg washing and drying machine is around 4,000 to 8,000 yuan. Therefore, the integrated washing and drying machine product has more price advantages, but the drying effect will be affected to a certain extent. The price of high-end washing and drying all-in-one products that do not affect the drying effect and occupy a small space are around 12,000 to 15,000. When the same effect is achieved, the overall price is higher than that of independent products.
To sum up: If you are short of money and space, choose a low-end all-in-one washing and drying machine; if you are not short of money or space, choose a high-end all-in-one washing and drying machine; If you are short on money and not short on space, you can choose at will according to your mood.
4. Analysis of the drying process of the clothes dryer
By observing the drying process, it can be found that according to the change characteristics of the fabric surface temperature and water loss rate, the whole process from wetting to drying of the fabric can be divided into a heating stage, a constant speed drying stage, a slowing speed drying stage, and a cold air blowing stage. stage.
1. The heating stage refers to the stage in which the wet fabric adjusts its own temperature in the environment, and the moisture content is almost constant. This is due to the low temperature of the fabric at this stage, which is not enough to provide the energy required for a large amount of evaporation of the fabric, so the migration rate of the moisture is very slow, and the energy provided by the heating wire power is mainly used for the increase of the fabric temperature rather than the moisture in the fabric lost. The moisture removed at this stage is mainly free water (moisture adsorbed on the surface of the fabric).
2. The constant speed drying stage refers to the stage in which the temperature of the fabric remains basically unchanged and the moisture content decreases at a constant rate. It is the main water loss stage of drying. At this stage, the energy provided by the heating wire is mainly used for the migration of moisture in the fabric, and the energy provided by the dryer to the fabric is equal to the energy required for the fabric to evaporate. Throughout the process, the fibers on the surface of the fabric are surrounded by water molecules and are always in a saturated state. The removed water is mainly free water existing on the surface of the fabric, in the gaps between yarns, and in the gaps between fibers. The migration rate depends on the external environment, that is, from the surface of the material. The rate of vaporization of water is determined. Moreover, the driving force for mass transfer is the difference between the water vapor density on the fabric surface due to intense evaporation and the water vapor density in the surrounding humid air (difference in water vapor pressure inside and outside). Therefore, at this stage, the drying efficiency can be improved by changing the external conditions, that is, using high wind speed and large air volume to take away the water vapor vaporized on the surface of the material during the drying process.
3. The stage of drying at reduced speed refers to the stage in which the surface temperature of the fabric increases significantly and the rate of decline of the moisture content of the fabric gradually decreases. At this stage, the surface of the fabric is no longer saturated and evaporation begins to enter the interior of the fabric. The moisture removed at this stage is mainly free water molecules existing in the interfiber spaces, and the migration rate depends on the diffusion rate of moisture inside the fibers. If over-baked, the hydrogen bond and van der Waals' force-based binding energy will be destroyed, resulting in capillary water (water in the fiber's internal void) and bound water (water molecules combined with fiber macromolecules through chemical bonds or hydrophilic groups) evaporation. The rate at this stage is significantly related to the outward migration rate of moisture inside the fabric, so the drying rate is obviously limited by the type of fabric to be dried and the heat and mass transfer rate of the material itself.
4. The stage of blowing cold air refers to the stage of realizing the temperature and humidity balance between the fabric and the environment. This phase involves little migration of moisture, but a rapid drop in temperature.
To sum up, each stage plays a different role in the fabric drying process, the type and quality of water to be removed are different, and the drying mechanism and drying rate are also different, so each stage needs to supply The energy, drying temperature, wind speed residence time, and the movement state of the clothes are different, and should be controlled separately according to actual needs in order to achieve the purpose of drying clothes quickly and efficiently. Therefore, it is unreasonable for the clothes dryer to adopt a drying mode with fixed parameters in the whole process. Instead, it should adopt a mode that adjusts drying parameters in real time according to the drying stage. Therefore, a phase-by-stage drying mode of positive and negative alternating rotation is proposed to make full use of the temperature, humidity and motion characteristics of the fabric during the fabric drying process, so as to maximize the drying efficiency of the dryer and realize the overall energy saving of the dryer as much as possible.
5. Analysis of drying mode of household clothes dryer
There are three drying modes of the warm air dryer: alternating positive and negative rotation in stages, single direction rotation in stages, and single fixed drying.
The drying energy consumption of the drying mode with alternating positive and negative rotation in stages is the smallest, the energy consumption of drying in the drying mode of unidirectional rotation in stages is the second, and the drying energy consumption of the single fixed drying mode is the largest. Compared with the single fixed drying mode, the unidirectional rotating staged drying mode saves 5.43% of the drying energy consumption, and the forward and reverse rotating staged drying mode saves 12.77% of the drying energy consumption. This is because: the staged drying mode can reasonably adjust each drying parameter according to the stage of drying, avoiding the energy used for excessive increase in fabric temperature, and maximizing the energy utilization rate of each stage. The following is a comparison of the advantages and disadvantages of the three Hongan models.
1. Comparison of drying time
Among the three drying modes, the drying time of the forward and reverse alternating rotating drying mode in stages is the smallest (saving 10% of the time), followed by the drying time of the single fixed drying mode, and the drying time of the single-direction rotating drying mode in stages Drying time is max. Comparing the drying parameter settings of the three drying modes, it is found that compared with the drying parameters of the single-direction rotating and staged drying mode, the power of the heating wire in the entire drying process of the single fixed drying mode is 4000W, and the power is lower. High, the drying air carries more energy, which is conducive to the evaporation of water in the fabric, so the drying time is shorter. The parameter setting of the whole process of the forward and reverse alternating phase drying mode is the same as the phase drying parameter setting of the single direction rotation, but it adds the positive and negative rotation alternately, and the fabric will not appear entangled or clumped in one direction. The contact area between the fabric and the drying airflow is increased, the drying thickness of the fabric is reduced, and the drying efficiency is higher, so the drying time is shorter.
2. Comparison of drying effect
Among the three drying modes, the final moisture content of the single fixed drying mode is the lowest. This is because the temperature of the fabric in the later stage of drying in this drying mode is the highest, which makes the internal water evaporate more fully, so the final moisture content is the lowest. In the staged drying mode, the surface temperature of the fabric in the later stage of drying is low, and it is difficult to fully migrate the internal bound water, so the final moisture content is relatively high.
3. Comparison of drying uniformity
Among the three drying modes, the drying uniformity of the forward and reverse alternating rotating and staged drying is the best, while the drying uniformity of the single fixed drying mode and the single-direction rotating and staged drying mode are poor, and the difference between the two not big. This is because the alternating rotation of the front and back is easier to shake the fabric, and the fabric is heated more evenly, so the drying uniformity is better.
6.The most suitable drying mode selection of the dryer
From the above analysis, it can be seen that adopting a suitable drying mode can significantly improve the drying efficiency of the dryer, the environmental and economic impact, and improve the appearance of the fabric after drying.
During the entire drying process, the surface temperature of the fabric and the moisture content of the fabric have obvious time-varying and staged characteristics. According to the surface temperature of the fabric and the characteristics of the instantaneous moisture content of the fabric, it can be divided into a heating stage, a constant speed drying stage, a slowing speed drying stage, and a cold air blowing stage. And the main function of each stage is not the same. The heating stage is mainly to increase the temperature of the fabric at the fastest heating rate; the constant speed drying stage is mainly to remove 60% to 70% of the water in the fabric at the maximum water loss rate, which is the main stage of drying; The stage is to remove as much moisture as possible in the fabric under the premise of ensuring that the surface temperature of the fabric does not rise too much; the stage of blowing cold air cools the surface temperature of the fabric to room temperature at the fastest rate. Therefore, the characteristics of each stage should be fully utilized to carry out stage-by-stage variable parameter drying to maximize drying efficiency.
The drying efficiency and post-drying performance of the forward and reverse alternating phase-variable parameter drying mode are significantly better than the drying efficiency and post-drying performance of the single fixed drying mode, and slightly better than the single-direction rotating phased drying mode. Drying efficiency and fabric performance. Compared with a single fixed drying mode, the drying time can be reduced by 10%, the drying energy consumption can be reduced by 15%, the flatness can be improved by 1 level, and the CO2 emission and use cost are both reduced.
The alternating positive and negative phase drying mode can not only achieve the purpose of energy saving, high efficiency, environmental protection, and no damage to clothes, but also provide a reference for dryer manufacturers to reasonably set drying programs.
The above are the details of the clothes dryer solution introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. for you. If you have electronic function development needs for household clothes dryers, you can trust us. We have rich experience in customized development of electronic products. We can evaluate the development cycle and IC price as soon as possible, and can also calculate the PCBA quotation for clothes hanger dryers. We are a number of chip agents at home and abroad, including MCU, voice IC, Bluetooth IC and modules, wifi modules. Our development capabilities cover PCB design, single-chip microcomputer development, software custom development, APP custom development, WeChat official account development and other hardware and software design. It can also undertake the research and development of smart electronic products, household appliances scheme design, beauty equipment development, Internet of Things application development, smart home scheme design, TWS scheme development, Bluetooth audio development, children's toy scheme development, and electronic education product development.
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