I Home I How it all began I VSBK Technology I VSBK Centres I Factfile I

Frequently asked questions :
What is the rate of production of a VSBK ?

Ans. It depends on the number of shafts you build. A 2-shaft kiln produces about 10,000
bricks per day (having a size of 230mm x 110mm x 70mm). Operation is round-the-clock
and annual production of up to 60 lakh bricks has been achieved from commercial
VSBKs operating in India and Nepal. The kiln can be operated throughout the year and
even during monsoon time. A kiln in Kathmandu, Nepal has been in operation
continuously for more than 500 days.

What advantages do I get if I switch over to a VSBK?

Ans. A VSBK gives you unmatched flexibility of operation, good product quality and
substantial saving in energy costs. You can plan a precise production schedule and
produce exact quantity of bricks that you require. Once operational, loading and
unloading is carried out simultaneously. In general, one batch of bricks is loaded (and
one unloaded) every one and a half to two hours. The bricks remain inside the kiln for
approximately 24 to 30 hours instead of the 20 to 30 days required with a BTK. This
reduces the working capital substantially.

Do I get bricks of good quality in a VSBK?

Ans. Yes, you can get bricks of high quality using a VSBK if you follow good firing practices.In fact, the products may even be superior to those of your existing traditional
 or BTK kiln. VSBK - fired bricks show a fine, deep red color and has a good, metallic ring depending upon the soil composition and particle size distribution.

What kinds of bricks can I fire in a VSBK?

Ans. Both wire-cut (extruded) bricks and hand-moulded bricks can be fired in a VSBK. The choice is entirely yours. Extruded bricks can achieve a compressive strength of up to 300 kg/cm 2 after firing. The VSBK is extremely versatile in operation. In addition, you can fire hand-moulded bricks together with extruded bricks in the same VSBK.
However, you can only fire walling bricks in a VSBK. Other clay products such as clay
roofing tiles or floor tiles cannot be fired using this technology. In a nutshell any regular
shaped, rectangular product having a minimum thickness of around 40mm can be fired
in a VSBK.

Is the Vertical Shaft Brick Kiln a profitable business?

Ans. Yes it is. The Vertical Shaft Brick Kiln allows you to retain complete control over product quality, unit production cost and pollution emissions. Fuel costs alone are at least 40% lower than those associated with the operation of conventional kilns. Throughout the year, your saleable bricks will represent more than 90% of your total brick production.
The VSBK kiln with two shafts can be set up in 2000 sq.m. of land, and 4 shafts in 4000
sq.m, excluding the brick-moulding area. With an initial investment of approximately 15
lakhs, sales of upto 35 lakhs each and every annum have been achieved with handsome
profit margins. From the second year your investment will be limited only to the working
capital requirement of approximately 1 lakh.

How do I know if the local soil is suitable for producing VSBK bricks?

Ans. The VSBK is amazingly versatile for firing bricks with different qualities of soil. In almost all regions, there are organizations, which have fully equipped and certified testing
laboratories. You should get your soil, coal, green bricks and fired bricks tested for
quality and performance only at these certified laboratories.
Generally, as a preliminary thumb rule, if good bricks can be made in a BTK the same
soil can be used in VSBK to make better bricks.

What kind of fuel can I use in a VSBK?

Ans. The choice of fuel is based on cost considerations and the quality of product desired.Based on the location, coal and even lignite pellets are being used effectively. However proper firing control and optimum quality is achieved with a low volatile coal having a calorific value between 4000 5000 KCal/kg. High calorific value coal is not
recommended for VSBK operation. Recommended coal size is between 50 to 100 mm.
In recent times where suitable coal is not available, VSBK has been operated with waste
biomass based green solid briquettes. It has the equivalent consumption to coal and
produces identical quality.
Do I need highly technical personnel for operating a VSBK?

Ans. Initially, yes. You will need specially trained firemen and firemasters for proper VSBK operation. The technology provider will provide on-the-job training for your firemen. This will normally take 3 to 4 weeks once the new kiln has been commissioned.

What is the life of a VSBK?

Ans. A VSBK can be used for many years if good firing and maintenance practices are
observed. The expected service life of a VSBK is between 10 to 15 years.
Can green bricks be made without the help of traditional moulders?

Yes, green bricks can be made even without moulders. There are various low cost
technologies to manufacture green bricks with unskilled workers. These bricks have a
frog and are superior in quality than normal hand moulded bricks.
What are the maintenance costs in a VSBK?

Ans. Normally the technology provider will provide with detail maintenance guides andprocedure. However normal maintenance practices of greasing and oiling of metal parts are to be followed daily. Normal operating procedures does not require any detailed
maintenance and repairing. Once in a year before start of the firing process the
refractory brick wall lining of shaft needs filling of joints with refractory mortar and
occasional replacement of a couple of refractory bricks. Maintenance costs in a VSBK
have been limited to approximately Rs. 10,000 per year.

Do my workers need to change working patterns?

Ans. Yes. Your workers will have to adjust their working habits. The VSBK firing systemrequires 24 - hour supervision of operations. One batch of fired bricks needs to be unloaded (and one batch of green bricks loaded) at regular intervals, normally every twohours. This means that even throughout the night, the VSBK needs to be staffed forregular loading and unloading operations of the kiln.

What are the environment benefits?

Ans. VSBK technology gives you unmatched benefits in environmental emission. Due to its lower coal consumption, loading pattern of green bricks and updraft nature of heat transfer, the pollution levels are considerably reduced. Compared to the Central Pollution Control Board, Government of India, norms of 750 mg/Nm 3 for suspended particulate matter in the case of Bulls Trench Kiln, the average emission of suspended particulate matter in case of VSBK is 150 mg/Nm 3 . Dust emission at the loading and unloading areas are considerably reduced making it amenable to safe working conditions.

What are the energy benefits?

Ans. Enviable energy benefits can be attained in VSBK when proper mixing process and right choice of fuel are followed. VSBK technology requires faster firing process (24hrs 36hrs) compared to traditional methods of firing. Thus to provide uniform heat and resultant firing quality, use of heat internally is a necessary pre-requisite. With proper engineering of soil mixes through the use of internal fuel, the external coal consumption can be reduced drastically. In some cases with plastic soil and medium calorific value (2300 KCal/kg) internal fuel e.g. sponge iron waste, good quality fired bricks have been produced at even 10 kg of external coal per 1000 bricks compared to normal 180 kg per 1000 bricks in traditional kilns.