New type fluidized-bed kiln gypsum powder production line
Cypsum powder fluidized bed calciner is special equipment applying
fluidifying technology for the calcination of gypsum powder. Its
heating medium is water vapour or heat-conducting oil. The calciner
is originally created by China. Now it is widely used in many
factories. It is characterized by:
1.Small valume ,High production capacity
The calciner realizes thorough fluidization of the material.
Therefore, it has no mixer or stirrer with it. Dense heating pipes
are fitted inside the calciner which provide enough heat exchanging
area in such small space.
In addition, the heat source of the calciner is saturated vapour or
heat conducting oil, whose heat-transfer coefficients are higher
than that of heat smoke by one order of magnitude. The high total
heat transfer quantity determines a high production capacity. Take
examples, a calciner with and hourly output of 5 or 6 T is only
1.3m in diameter.And a 20T/h one has a diameter of 2m. In this
respect,no external heating calcining equipment can compare with
the fluidized bed calciner.
2.Simple and firm structure
Because of the fluidization of the materical, the calciner has no
gearing parts .The simpleness in structure provides great
convenience to the maintenance of the machines and equipments
And the low-temperature heat source (vapour is 200℃,heat-conducting
oil is about 260℃) prevents the calciner from being burnt out. This
reasonable design makes a long service life of the calciner.
3.Compact layout
The calciner is vertical in structure. Above the furnace body is
the dust collector,which becomes part of the calciner. Occupying
few land prevents the dust collecter from condensing at the same
time.
4.Low energy consumption
The calciner consumes less heat and power energy. The thermal
efficiendy of the calciner is above 95%. The final thermal
efficiency depends upon the heat efficiency of the boiler and that
of the calciner. Since mature technology has been applied in steam
boilers and heat-conducting-oil boilers,both has high themal
efficiency (the former is 60 -70%,the latter is 70-80%).
Working with above boilers, the heat efficiency of the calciner can
achieve 57-67% and 67-76%. Few ordinary external heating calcining
equipments can surpass 50% in this respect, though heated directly.
To produce a ton building gypsum ,the calciner consumps heat energy
of 7.7×105KJ. Without any stirrer,it needs less electric energy.
The material is fluidized by water vapour from the dehydration of
gypsum,during which few air is needed.A low-power air blower can do
the work without difficulty.The calciner consumes much less power
than any traditional calcining equipments.For exampleto produce 3
tons of building gypsum powder the installed capacity of a calciner
is more or less 22KW.
5.Easy operation and control
One character of the fluidized bed is the material in it is heated
evenly.Under a setting tempratue ,qualified powder can be produced
continuously.
6.High quality of gypsum powder
Heated in low temperature, the gypsum is not apt to be overburnt.
Discharged at a proper temperature, semi-hydrated gypsum can be
produced, containing less than 5% anhydrite gypsum and no dehydrate
gypsum at all. Such composition makes stable the physical
properties of the gypsum powder.
7.Low operation cost & capital construction investment
Because of the small volume, simple structure and less land
occupation, the investment in capital construction is lower than
any other calcinating equipments. And it costs less in opration for
its low energy consumption, less maintenance task and long service
life.
A Comparison between Various Dehydraters |
| Coal Consumption | Thermal Efficiency |
Intermittent cooker | 150-160kg/T | 25-30% |
Rotary kiln(external combustion type) | 120-130kg/T | 30% |
Continuous cooker | 90-100kg/T | 40% |
Fluidized bed calciner | 40-52kg/T | 60-70% |
