An Introduction to Indirect Dryers

Hi, I am writing this blog on behalf of KERONE a 40 year young (#40yearsyoung) organization has emerged as an quality manufacturer of technically advanced and challenging heating and drying system, to introduce its reads about the some aspects of the Indirect dryers. The word indirect itself defines that these types of the dryers in which the heater and the subject material under the drying process are separate. The formal definition given by the Hall (1980) that “the indirect dryers are dryers in which the heating medium does not come into contact with the product being dried”.
Unlike direct contact dryers in the indirect dryers the wet material to be dried is heated by means of contacting the material to heater surface i.e. heater heats contacted surface (heat exchanger) and wet materials in placed on such heated surface, this process is known as conduction. The greatest concern points while selecting the dryers are 1) Material to be dried 2) Product quality that is required; hence these points are always required to be taken in to consideration before selecting best fit for of the indirect dryers. The temperature and heating source also largely get influenced by the residence time (time for which the material will reside within the heater) of subject material, as to have lower residence time the high heat source is required to get higher temperature and lower temperature is required for the longer residential time.
Advantages of the Indirect Dryers:

  • The indirect dryer offer higher energy efficiency as compared to direct dryer
  • The loss of the energy through exhaust gas stream as minimum
  • Waste heat can also be utilized for the drying
  • Being closed loop the vapor produced while drying are also utilized to increase the temperature
  • Indirect dryers need minimum cleaning of the exhaust gas as the exhaust flow is low
  • Suitable for the toxic and active materials as low emission of fines and particles from the dryer
  • Vacuum drying can also be easily achieved 
  • Ideal for heat sensitive materials
  • Risk of fire and explosion hazards is reduced to greater extend as drying is from conduction 

Limitation of the Indirect Dryers:

  • Limitation of rate of heat transfer and availability of the heat transfer areas for large scale equipments
  • Indirect dryers also have reduce upper limit of drying temperature and maximum throughput when compared to direct dryers
  • Indirect dryers have typically higher capital costs due to the need for heat exchange surfaces

Application of Indirect Dryers:
Indirect dryers have proven their successful usage in drying of following applications:

  1. Food and dairy products 
  2. Baby Food 
  3. Milk and buttermilk 
  4. Potato flakes
  5. Black Carbon and Etc. 

If you wish to have more information or have any business enquiry then write us on .

Importance of Dryer for Ceramic Industries

High quality ceramic products are finding application in multiple domains such as pottery, archeology, construction, design & decoration, foundries, electronics & electrical and etc. as the demand of ceramic products are increasing in the respective sectors, the pressure on producers to deliver the right amount of the ceramic or compound products has increased significantly. The ceramic manufacturing (#ceramicmanufacturing)) process involves majorly 4 steps: Step- 1) Selecting the raw material Step -2) Preparation of Raw material (i.e. clay of production) step-3) providing the desired shape and size to ceramic product (i.e. Molding the ceramics) step-4) Drying (to maintain the mold shape). The ceramics materials are sensitive to the surrounding atmosphere hence drying is very important for precisely designing the mold, determining the high-efficient heating rate and maintaining the desired level of drying temperature and duration (#importanceofdrying). With the time of science of ceramic material, production process and demand are changing and accordingly the required type and rate of drying.
The quality ceramic production process requires drying during the preparation process such as grinding, mixing, granulation as first phase of drying, second phase of drying appears after the molding to remove the water/moisture level present to achieve the desired strength and maintain the mold form. The quality of ceramic is highly affected by the 1)rate of rise of temperature in dryer 2)irregular deformation and shrinking 3)irregular or none-uniform rate of drying 4)Creating of black spot or none dryable spot due to complex shape(#qualityceramicproduct). The drying processes are very important for the accurate design of molds and the achievement of highly quality majorly with the ceramic having complex shapes or large sizes in which the uniform density distribution is very difficult to achieve.
IR Tunnel OvenTunnel type dryers are typically used for continues drying of ceramics, hence the drying temperature and length of the tunnel are very critical components; hence it’s always advisable to consult the experts of the field such as KERONE of the selection best suited drying system. KERONE is holding 40 years (#fortyyearold) of rich experience in designing the critical dryers for the quality applications. KERONE’s Infrared based dryer for the ceramic to achieve the uniform and high rate of drying, but sometimes not effective with complex shapes and large thickness. KERONE’s microwave dryer helps ceramics to dry from within the material i.e. from the inner to outer part of material. KERONE (#innovationatkerone) also provides hybrid drying system for ceramic drying, for more details kindly contact us at