- Model NO.: LVGP-8TH
- Control Type: CNC
- Automatic Grade: Automatic
- Crusher: Hammer Type
- Calcining: Vertical (Fluidized Bed)
- Burner: Original Germany Brand
- Workers: 18/Day
- Silo: Seller Supply Drawing, Buyer Makes It on Site
- Specification: CE, SGS, BV
- HS Code: 8474809090
- Certification: ISO 9001:2008, BV
- Crushing Degree: Ultra-Fine Mill
- Raw Material: Gypsum Rock
- Mill: One Set
- Bagging: Rotary Type
- Machines Area: 26 X 18m
- Final Production: 80 to 325 Mesh
- Trademark: LVJOE MACHINERY
- Origin: Shijiazhuang, Hebei Province
1. The gypsum stone is crushed into granule less than 25mm with crusher. It's stored in raw material silo, then conveyed into grinding mill to make gypsum powder. The powder is classified through a classifier. The qualified powder in required fineness shall be carried to the calciner, while the unqualified powder shall be returned to the grinding mill for further process. The calcined gypsum powder (it's usually called Plaster of Paris) shall be stored in the finished product silo for preparation of plasterboard raw material.
II Fluidized bed calcining process:
As the gypsum industry developing, the gypsum powder demand becomes larger and larger in many fields. Meanwhile the requirement for gypsum powder quality becomes stricter. Therefore the gypsum power process improves gradually. Drying and dehydrating the raw gypsum powder is a critical process and the most difficult to control. After many years of research and experiment we have successfully developed the advanced calcining device-fluidized bed calciner, suitable for all kinds of gypsum powder production.
2.1 working principle
The fluidized bed calciner mainly is composed of dense small diameter piping coils which radiate heat of enclosed thermal oil through heat exchanger. At the bottom of the calciner a roots blower is installed.
The blower sucks cold air into the calciner through the grid plate. The blown raw powder inside the calciner becomes boiling. At certain temperature the dried and dehydrated gypsum powder turns lighter and overflows out. The finish powder has a stable quality, and its crystal water content and final setting time are easy to control. The calciner is equipped with high efficient (more than 95%) dry electrostatic precipitator to control air pollution.
2.2 Simple structure and long service life
Because the gypsum powder is fluidized during calcinating process, the calciner doesn't have rotary unit. The fluidized bed calciner structure is simpler than the traditional calciner. It's easy to manufacture. Almost no maintenance work is required from starting to production. The working heat source is low temperature that won't burn out the calciner at any circumstances. Thus it has a very long service time.
2.3 Compact and less land occupation
The calciner is vertically installed. The dust collector covers the top of the calciner to avoid dew. The two units in cooperate together. They take less land occupation.
2.4 Low energy consumption
The fluidized bed calciner has low heat energy and electricity consumption. Heat energy: from heat source to raw gypsum powder only little quantity of heat are lost for cold air sucken by blower and calciner body, most heat energy is used for dehydrating the gypsum powder. Its heating efficiency factor is more than 95%. However it's the second heat source of calcination. The ultimate heating efficiency shall be two efficiency factors multiplication of calciner and boiler. Steam boiler and thermal oil boiler are mature technology with high heat efficiency. The steam boiler efficiency usually reaches 60-70%, thermal oil boiler is 70-80% (we adopt for the calcination system).So the ultimate heat efficiency shall be 57-67% with steam boiler, and 67-76% with thermal oil boiler. Usually the traditional direct fired calciner use the first heat source (suitable fuel) directly which heat efficiency is less than 50%.The index of heat consumption of fluidized bed calciner is 7.7×105KJ/1000kgs gypsum. Electric energy: The fluidized bed calciner has no stirring device inside. The gypsum powder is fluidized with steam only. The blown cold air is not much. It just needs a small power blower. Therefore the fluidized bed calciner saves more electric energy than the traditional direct fired calciner.
2.5 The finished powder has good quality, ideal composition and stable physical property
As for low calcining temperature the raw gypsum powder is hardly overheated. Just take care to control the outlet temperature. The finished powder shall not have dehydrate gypsum, the dehydrate gypsum content shall be within 5%, other is semi hydrated gypsum. The composition is ideal and the powder has a stable physical property.
To meet the above requirement for good quality product we already developed a whole set of calcination system for gypsum powder. The equipment is mainly made of high quality steel. For example, the thermal oil piping coil is made of high quality seamless steel pipe (applied Standard: GB3087-82).Steel plates are carbon steel or low alloy steel special for boiler use (applied standard: GB713-86).Supporting stand is made of China national profile steel. In addition when welding the parts, the operator is required to have welding professional certificate. The prime thermal oil pipe coil shall have water pressure test, tested water pressure 0.5-0.6Mpa for more than 30 minutes. During the test period any water leakage is not allowed. No leakage means passed quality.
IV Workers per day & per shift
The crushing system: 2 workers/day (including the forklift driver)
Grinding system and calcining system: 2 workers/8 hours (6 workers/ day)
Heating supply system: 2 workers/eight hours (6 workers/ day)
Mechanic: 1 worker/day
Total: 16 workers
The time of production: 330 days/year×24 hours
The output of one hour: ≥8T/hour (finished powder)
VI Quality of final production
Equal to or exceeding the requirement of the national calcined gypsumstandard
VII The requirement of the environment:
The output of the dust of the high-voltage electrostatic dust collector reaches to the local environment demands
VIII The related parameter of the product (GB9776-88 calcined gypsum)
1. Fineness:≥80 mesh
2. Antiflex strength (it is related to the raw material): ≥1.8Mpa; compression strength: ≥3.0Mpa
3. Main component:
semi-hydrated gypsum content: ≥80% adjustable
dehydrate gypsum content: <5% adjustable
Soluble anhydrous gypsum: <5% adjustable
4. The initial setting time: 3~8min adjustable;
The final setting time: 6~15min adjustable
5. Standard consistency: 78~85% adjustable