GMP Hot Air Circulation Oven

Hot Air Circulation Oven: The Ultimate FAQ Guide

Before importing hot air circulation oven from China, read this guide.

It covers everything you need to know about this material processing equipment including, parts, working principle, features, quality standards, and advantages, just to mention a few.

Keep reading to learn more.

What is a Hot Air Circulation Oven?

A hot air circulation oven is a piece of equipment that will get rid of moisture from products.

It will provide a fast and reliable drying process.

Hot air circulation oven

What Components of Hot Air Circulation Oven?

A hot air circulation oven has many components that all work together to achieve an effective drying process.

An operator needs to understand how these components operate when using this equipment.

Depending on the type of hot air circulation oven, it may come with different components.

Here are the basic parts you can find on a hot air circulation oven:

 Parts of hot air circulation oven

Control Panel

This is a central location where the operator will monitor and set drying parameters.

It has a programmable logic controller and a human-machine interface with graphics for easy usage.

Parameters that you can set include the drying time and temperature.

It shows the temperature, timer, power status, etc.

Heat Source

During the drying process, the heat source will provide heat that will assist in drying the products in the oven.

A heating element in the oven will determine how the heat circulation will occur in the oven.

The various sources of heat include vapor, electricity, or infrared.

This component can achieve high temperatures ranging from 50 °C to 350 °C depending on the source of heat.

Sensors

A hot air circulation oven operates at high temperatures that are dangerous to the operators.

The sensors will send a report to the control panel indicating any malfunction in the system.

It may also shut the oven down in risky scenarios that will protect the heating chamber.

Also, the sensors may sound an alarm to warn the operators of impending dangers.

Insulation Unit

This component will minimize the chances of heat escaping into the environment during the drying process.

When heat escapes, the oven may not be efficient, take longer drying times, and will consume a lot of power.

One way heat may escape out of the oven is via conduction as the components get hot in the oven.

Besides, it will also protect the operator from burning when they come into contact with the oven.

Door

This is a highly durable stainless steel that the operator can open and close the oven.

It allows the operator to place products in the oven and remove them after the drying process.

Also, it has safety locks that will ensure a complete closure during the process.

Motor Systems

This component will convert electrical energy to mechanical energy.

It helps in driving the fan in the oven that assists in circulating air in the heating chamber.

Air Outlet and Inlet Valves

A hot air circulation oven needs air to achieve the desired drying effect.

These valves will allow air to flow in and out of the heating chamber.

Air will enter the oven when it is dry and leave the oven when it has moisture.

The moisture comes out of the products during the heating process.

Trays

These components will hold the products in the heating chamber.

It allows proper placement of the products within the oven.

Different hot air circulation ovens come with several trays that hold the products.

Large ovens come with several trays as it can hold large amounts of products.

Air Blower

This system assists in blowing hot air within the heating chamber from the heating elements.

It can come in different designs depending on the type of hot air circulation blower you have.

Handles

This part is on the door that will allow the operator to easily open and close the system.

It is a poor conductor of heat thus remains within temperatures that are easy to hold.

How does a Hot Air Circulation Oven Work?

Understanding how a hot air circulation oven works are vital when you intend to operate it.

Here are the stages highlighting how the oven works:

Stage One: Preparation

The first step involves making sure the oven is working as it should.

All components must be in good condition before proceeding to use the oven.

Evenly place all the products that you need to dry on the trays.

Place then in the oven, close the doors securely, then power up the machine.

Input the drying time and temperature via the control panel and start the process.

Stage Two: Drying Process

The air inlet valve will allow air to flow within the heating chamber.

Heating elements will heat the air and make them lighter, so the air will rise.

Concurrently, the air blower will assist in circulating the air within the system.

Hot air will rise as cold air enters the system hence, a circulatory motion occurs.

Air circulates in the heating chamber until all air has the same temperature level achieving a uniform drying process.

The hot air will take up the moisture within the products leaving them dry after every pass.

Air that now has moisture will exit the hot air circulation oven via the outlet valve.

This ensures that the products do not start absorbing the moisture once again.

The drying process will proceed as per the parameters fed on the control panel.

Stage Three: Final Process

After the drying time expires, the hot air circulation oven will stop operating.

The operator will proceed to open the oven and remove the products then, allow them to cool.

What Types of Hot Air Circulation Ovens are available in the market?

There are various types of hot air circulation ovens available.

These ovens can operate as either forced air hot air oven or static air hot air oven.

Forced air hot air oven works by heating air and circulating it within the heating chamber through the assistance of fans.

This circulation achieves a uniform temperature in the system while allowing uniform drying of products.

A static air hot air oven will dry the products in the heating chamber by using heating coils at the bottom of the oven.

The heat will slowly rise in the heating chamber hence it takes quite some time to achieve the right temperature level.

Heating is not consistent as there is no circulation of air in the heating chamber.

Here are some of the hot air circulation ovens you can find:

Special Purpose Hot Air Circulation Ovens

This kind of oven comes with its specific purpose.

They include:

Burn-in Hot Air Circulation Oven

This oven is good for electronic products as it can achieve a maximum temperature level of 260 °C.

It uses nitrogen as the main air that will assist in the drying process in the heating chamber.

Reach-in Hot Air Circulation Oven

It achieves a uniform heating process since it comes with shelves that allow a horizontal airflow.

This oven is suitable for products that need over 100 air exchanges every hour to achieve the desirable drying effect.

Clean Process Hot Air Circulation Oven

It is suitable for sterilization as it can achieve a temperature above 260 °C.

Vacuum Hot Air Circulation Oven

This oven is suitable for drying large amounts of products.

It will produce no gas thus, it is good for hardening, brazing, heat treatment, etc.

Metallic products work well with this oven.

Specific Application Hot Air Circulation Oven

These ovens are suitable for an exact function or operation.

They include:

Depyrogenation and Sterilization Hot Air Circulation Oven

This type of oven can achieve a high temperature of up to 280 °C.

It allows the incorporation of additional custom features.

Dry Application Hot Air Circulation Oven

These ovens can operate at high temperatures of about 260 °C.

They are also capable of using steam as the main source of heat during the drying process.

Steam can achieve a temperature of 90 °C.

What should you Consider when Choosing a Hot Air Circulation Oven?

Inside hot air circulation oven

Several factors will dictate the type of hot air circulation oven that is suitable for your firm.

These considerations will assist you to choose the best oven that will meet your production needs.

They include:

The capacity of the Oven

Ensure the oven can contain the appropriate amount of products that you need to dry per unit time.

Commercial ovens can hold large amounts of products than small scale ovens.

Heating Element

Choose a hot air circulation oven whose heating element will help you achieve proper drying of your products.

Quality Standards

It is vital to select a hot air circulation oven that meets all international quality standards.

This is to ensure the safety of operators and the products.

Also, it ensures the reliability, effectiveness, and acceptability of the oven in the market.

Forced Air Versus Static Air Hot Air Oven

These two ovens differ in terms of air circulation within the heating chamber.

A forced air circulation oven will achieve a uniform and effective drying that a static air hot air oven.

This is because it comes with fans that assist in air circulation.

Body Material

Select hot air circulation ovens that are of durable stainless steel.

This ensures it performs optimally and will last for long.

Budget

The amount you have will influence the type of hot air circulation oven you can afford.

Despite the budget, always go for an oven that is suitable for your production needs.

Technology

As the world advances, technological advancements are several.

The level of technology that the hot air circulation oven has will influence its effectiveness.

Besides, good technology allows you to achieve the best drying techniques.

Efficiency

Always purchase a hot air circulation oven that will achieve quality drying for your products.

Dimension of Machine

Hot air circulation ovens come in different designs and configurations.

Purchase an oven that will comfortably fit your work area.

Larger commercial ovens need more work area that small scale hot air circulation ovens.

Maintenance

Having a hot air circulation oven that will be easy to maintain and repair will benefit your firm.

Also, ensure the spare parts are easy to acquire in the market.

Besides, being able to replace parts easily will reduce the oven’s downtime.

What are the Advantages of a Hot Air Circulation Oven?

There are several advantages to using a hot air circulation oven.

They include:

 Hot air circulation oven

• It is easy to install the dry heat cabinet and it has relatively low operating costs.
• This oven is not toxic meaning; it does not affect the environment negatively.
• It does not corrode metallic products.
• They require no water.
• Pressure builds up within the oven is very low hence safe to work with.
• The heat will effectively penetrate materials.

What are the Disadvantages of a Hot Air Circulation Oven?

The disadvantages of this oven should not deter you from purchasing one.

They include:

• It takes a long time to effectively dry products as the heat penetrates products gradually.
• The high temperature is not conducive for most products.
• Dry heat may not kill organisms such as prions.

What are the Applications of a Hot Air Circulation Oven?

Aside from drying, there are several applications of a hot air circulation oven.

They are:

Tempering

The oven can release the brittleness of products hence eliminating the internal strain.

It applies varying heat rates on products via convection before cooling.

Testing

The varying heat levels in the heating chamber can test the stability and strength of products.

Also, it can test for any problems within the products.

This assists in determining if the products are ready for market.

Drying

These ovens will achieve a reliable drying process by eliminating moisture from the products.

Sterilization

The high temperatures of air within the oven will eradicate transmissible agents.

Vulcanization

This process will harden products through the different heat levels in the oven.

Aging

The heat in the ovens will assist in aging products.

This means changing the physical properties of these products.

Curing

Hot air circulation ovens can build durable bonds between the monomers of various products.

Besides, it can assist in growing materials in ever-increasing temperature levels.

Annealing

This involves toughening the products by applying internal stress to products via the heating process.

Polymerization

It involves enhancing reactions in monomer molecules.

Also, it includes the chemical reactions that will form polymer chains.

Conditioning

This will assist in increasing the shelf life of various products.

How does a Hot Air Circulation Oven compare to a Vacuum Oven?

Vacuum oven

The main difference between these two ovens is their mode of drying.

Hot air circulation oven uses hot air that will evaporate moisture from products.

This happens through the convection method.

A vacuum oven will remove moisture from fragile products.

It eliminates moisture from combustible products and operates at temperature ranges of between 200 °C and 250 °C.

After moisture removal, the product reaches equilibrium in a hot air circulation oven, where no more moisture can get out.

In a vacuum oven, the moisture reduction would continue until all moisture gets out.

How does a Dry Heat Sterilizer compare to an Autoclave?

Dry heat sterilization uses an oven that will apply heat to remove microbial life after some time.

Autoclaving involves applying time, pressure, and temperature to eliminate microbial life.

When using steam pressure, autoclaving needs a minimum temperature of 121 °C, 15 PSIG, for 15 minutes.

Dry heat sterilization needs one hour at 171 °C or two hours at 160 °C to achieve sterilization.

Autoclaves are costlier than dry heat sterilization.

Autoclaves that use steam can process several products at the same time within a short time.

On the contrary, dry heat sterilization takes a long time to process products.

The operating cost for both autoclave and dry heat sterilization is relatively the same.

It is easy to maintain dry heat sterilizers than it is to maintain steam autoclaves because they have a simple design.

Autoclaves can handle all products that can hold heat and moisture.

Dry heat sterilization will sterilize products that moisture can damage or steam cannot pass through.

Autoclave

How does Freeze Drying compare to a Hot Air Circulation Oven?

Hot air circulation oven uses heat to dry products.

It heats and circulates hot air in the heating chamber to eliminate moisture from products.

Freeze drying removes moisture thus, assisting in preserving products.

Freeze-drying involves freezing products while lowering pressure and adding heat that will allow products to sublimate.

Freeze dryer system

What is the Use of a Hot Air Circulation Oven in a Laboratory?

Several medical industries use a hot air circulation oven to sterilize their pieces of equipment.

This is because it is simple, easy to operate, and cost-efficient.

The uses include:

• Dry sterilization
• Dry heating
• Moist sterilization

What are the Maintenance Practices of a Hot Air Circulation Oven?

It is vital to maintain a hot air circulation oven to ensure it operates properly and remains durable.

Conduct quarter or semi-annual inspections to ensure all components are in good working condition.

Repair faulty doors that will cause heat to escape during the heating process.

Repair all electrical components to minimize electrocution or fire hazards.

Replace worn-out insulation systems to minimize heat loss via conduction.

Regularly clean the air inlet and outlet to remove clogs that might inhibit the heating process.

Replace parts with genuine products to avoid oven break down.

What Items can you Dry in a Hot Air Circulation Oven?

There are several products you can dry using a hot air circulation oven.

They include:

• Herbs
• Glassware like Petri dishes, pipette, test tubes, etc.
• Materials that have oils
• Metallic pieces of equipment such as blades, scalpels, scissors, etc.
• Powders like starch, sulfadiazine, etc.
• Granules

 Hot air circulation oven

What are the Quality Standards that a Hot Air Circulation Oven should conform to?

The quality standards will ensure the oven is safe during operation.

Also, it ensures the reliability, dependability, and efficiency of the oven.

These standards include:

• Food and Drug Administration [FDA] quality standard
• International Organization for Standardization [ISO] quality standard
• European Union CE mark of quality
• Current Good Manufacturing Practices [cGMP] quality standard
• Restriction of Hazardous Substance [RoHS] quality standard

What are the Salient Features of a Hot Air Circulation Oven?

Here are some salient features that you can find in such an oven:

• GMP certification design
• Tray quantity of between 12 and 192.
• Steam, electric, hot water, or infrared heat source.
• Adjustable drying temperature.
• Energy-saving and economical.
• Ease of operation.
• Air circulation capability.
• A low noise production level during operation.
• Easy installation and maintenance.

What is Depyrogeneration?

This incorporates removing pyrogens from a solution in an injectable pharmaceutical.

Pyrogens are substances that can cause fever.

What is the Cost of a Hot Air Circulation Oven?

The cost may vary due to various factors such as:

• Manufacturer
• Discounts and offers
• Year of manufacture
• Level of technology
• Supply and demand

The cost of a hot air circulation oven can range between 255 US dollars to 26000 US dollars.

How can you Troubleshoot a Hot Air Circulation Oven?

Troubleshooting helps you detect problems and fix them without much technical know-how:

Inconsistent Temperature

Recalibrate the thermometer using the user manual guide.

Replace faulty thermostats.

The Oven does not Heat Up

Repair or replace faulty heating elements.

Doors will not Shut

Turn off the oven, inspect the hinges and replace if necessary.

Replace faulty door springs and silicone or rubber gaskets.

Replace faulty sensors.

Interior Lights are off

Remove and reinstall the bulbs.

Replace faulty bulbs.

What are the Principles of Heat Transfer and Circulation in a Hot Air Circulation Oven?

These principles are:

Convection

Heat flows from one part to the other due to temperature differences.

Radiation

This involves thermal energy transfer through photons to an object.

Circulation

Fans in the oven will increase air circulation in the heating chamber thus distribute heat.

What are the Validation Documentations a Hot Air Circulation Oven has to have?

This validation documentation is:

Design Qualification

It will highlight the design of the oven to address the production needs, compliance, and will perform its work.

Installation Qualification

This happens during or after the installation of the oven at the user’s work area.

Operational Qualification

It will indicate that all components of the oven function as they should.

Performance Qualification

Indicates that the oven performs as per the specifications and user’s requirements during operation.

Depending on your specific needs, SaintyCo offers a range of hot air circulation pharmaceutical ovens.

Contact us today for high performance and energy-saving hot air circulation oven available at affordable prices.