What Are The Energy-saving Methods Of Dryer Machine?

As we all know, the energy consumption of the machine has always been a concern of pharmaceutical manufacturers.

High energy consumption means that the machine is powerful and the later maintenance cost will be higher.

So, where should we focus on solving this problem?

Do you have any ideas？

Never mind, through this article you will get some concrete energy-saving methods to solve the dryer machine’s higher energy consumption.

Energy saving methods of dry machine can be summarized in five directions:

First, reduce heat loss during the drying process.

Second, reduce evaporation load of dryer machines.

Third, increase the inlet air temperature of the dryer machine and reduce the temperature of exhaust gas at the outlet of the dryer machine.

Fourth, partial exhaust gas circulation.

Fifth, recover heat from the exhaust gas at the outlet of the dryer machine.

Reduce heat loss during drying process

First of all, you should have a certain understanding of the heat loss of the dryer machine.

Generally speaking, the heat loss of the dryer machine will not exceed 11%. If the insulation of large and medium-sized production equipment is appropriate, the heat loss will be about 6%.

But it does not mean that the thicker the insulation layer, the better the insulation work of the dryer machine.

This is actually a misunderstanding.

Therefore, if you want to do a good job in the insulation of the dryer machine, you need to determine an optimal insulation thickness according to your experience.

In order to prevent leakage of the dryer machine, you need to use the forced draft fan and induced draft fan in series, and then make the system in a zero pressure state through a series of reasonable adjustments.

Do you know why you need to do this?

This is because it can avoid the decrease of the thermal efficiency of the dryer machine due to the leakage of drying medium or the leakage of the ambient air.

Reduce evaporation load of dryer machine

Before the materials enter the dryer machine, the materials are preliminary dewatering through filtration, centrifugal separation or evaporation of the evaporator, which can increase the solid content of the materials and reduce the evaporation load of the dryer.

This is one of the most effective ways to save energy for dryer machines.

Can liquid materials also save energy after treatment?

Yes, it can.

As for liquid materials (such as solution, suspension, emulsion, etc.)

Because the sensible heat of air is used for heating materials in the dryer machine, and the latent heat or waste heat of water vapor is used for preheating.

For spray drying, preheating of the material liquid is also conducive to atomization.

Increase the inlet air temperature of the dryer machine and reduce the temperature of exhaust gas at the outlet of dryer machine.

You should know that increasing the inlet air temperature of the dryer machine is conducive to improving the dryer machine’s thermal efficiency according to the definition of its thermal efficiency.

But you should know that

The temperature of the inlet air is limited by the allowable temperature of the product itself.

In general, the energy consumption of a dryer machine includes two ways

One is evaporation of water, the other is removal of exhaust gas. The latter part accounts for about 15% to 40%, some as much as 60%.

Therefore, reducing the exhaust gas temperature at the outlet of the dryer machine is limited by two factors.

First, you need to ensure the moisture content of the product (the outlet exhaust gas temperature is too low, the moisture content of the product increases, and the required moisture content of the product cannot be reached).

Second, you should ensure that its temperature is 20-60 ℃ higher than the dew point when the exhaust gas enters the cyclone separator or bag filter.

Partial exhaust gas circulation

The drying system with partial exhaust gas circulation is adopted, which is mainly because the system makes use of part of the waste heat in partial exhaust gas to improve the thermal efficiency of the dryer machine.

However, this method will have one disadvantage.

With the increase of exhaust gas circulation, the moisture content in hot air will increase, and the drying rate will decrease, which will increase the drying time of wet materials and increase the cost of dryer machine.

Therefore, there exists an optimum amount of exhaust gas circulation. General exhaust gas circulation is 20% - 30%.

Recover heat from the exhaust gas at the outlet of the dryer machine

In addition to the above-mentioned energy-saving method of using part of the exhaust gas circulation to recover heat.

You can also use indirect heat exchange equipment to recover heat from the exhaust gas at the outlet of the dryer machine.

Common heat exchange equipment include heat wheel heat exchanger, plate heat exchanger, heat pipe, heat pump, etc.

In recent years, with the emergence of the energy crisis and the rising energy prices.

It is necessary to take measures to change the operating conditions of the dryer machine, select the dryer machine with high thermal efficiency, and recover part of the heat in the exhaust gas to reduce production costs.

How will the dryer machines develop in the future?

Further research on drying mechanism and drying characteristics of materials will be the development direction of dryer machine in the future.

The improvement and development of the dryer machine should be carried out under the optimal operating conditions for different materials.

After the development of the dryer is confirmed, what is its development trend?

Large scale, high strength, high economy, and improving the adaptability to raw materials and product quality are the basic development trends of the dry machine.

In addition, in the development process of dryer machine, energy saving and comprehensive utilization of energy are also particularly important.

Such as adopting various combined heating methods, transplanting heat pump and heat pipe technology, developing solar dryer machines, etc.

At the same time, the automatic control technology of the dryer needs to be developed to ensure the realization of the optimal operating conditions.

In addition, with the attention of mankind to environmental protection, there is another direction that is also very worthy of in-depth study.

Improving the environmental protection measures of the dryer to reduce the leakage of dust and exhaust gas.