Evaporators are used to concentrate a solution, separating the vapor from the solution. All evaporation equipment contains a heat exchanger for heating the process solution and a means to effectively separate the vapor from the residual liquid, called a vapor separator. Evaporator performance is rated by Lbs per hour or Kg per hour of evaporation. The greatest increase in steam economy is achieved by reusing the vaporized solvent. This is done in a Multiple Effect Evaporator by using the vapor from one effect as the heating medium for another effect in which boiling takes place at a lower temperature and pressure. Another method of increasing the utilization of energy is to use a Thermo Compression evaporator, in which the vapor is compressed so that it will condense at a temperature high enough to permit its use as the heating medium in the same evaporator. This type is also called a MVR or mechanical vapor recompression.
Short tube vertical evaporators are natural circulation evaporators. These units consist of short tubes 4-6 feet long and 2” to 4” in diameter set between two horizontal tube sheets that span the evaporator body diameter. The tube bundle contains a large circular down comer that returns concentrated liquid above the top tube sheet to below the bottom tube sheet for product withdrawal. The driving force for flow of liquid through the tubes is the difference in density between the liquid in the down comer and the tubes.
Long tube vertical evaporators accomplish more evaporation than in all other types combined. They are also natural circulation evaporators. They are also categorized individually as rising film, falling film, and rising/falling film types. Basically these units consist of a vertical single pass shell and tube heat exchanger discharging into a relatively small vapor head. Tube length is typically12’ to 36’; and the tube diameters are from 0.75” to 2” OD. Units may be once through or recirculating, depending upon the application. Long tube evaporators are the most economical design.
Forced circulation evaporators are made in a variety of arrangements for services where the feed and/or product liquor has a tendency to salt or scale and where the viscosities of the solutions are so high that natural circulation is not feasible. Force circulation is achieved by using pumps. Forced circulation leads to high tube side velocities and higher heat transfer coefficients and smaller heating surfaces. The pump withdraws liquor from the flash chamber and forces it through the heating element back to the flash chamber. Circulation is maintained regardless of the evaporation rate so this type of evaporator is well suited to crystallizing operations where solids must be maintained in suspension at all times.
Thin Film or Wiped Film are agitated evaporators - essentially a large diameter jacketed tube, in which the product is vigorously agitated and continuously removed from the tube wall by scraper blades or wipers mounted on a shaft rotating inside the tube. The material to be processed is continuously spread as a thin film on the tube walls by the mechanical agitator. This permits processing of extremely viscous and heat sensitive materials, as well as products that crystallize. The heating medium may be steam or hot oil on the jacket side.
Condition: Used
Material: Stainless Steel 304
Manufacturer: Gouda
Total Heat Transfer Surface Area: 16.2 m² (174.4 ft²)
Diameter: 1,226 mm (48.3 in)
Internal plated for crystallizing the product, with wipers driven by the rotating shaft.
Height: 4,572 mm (180 in). Orientation: Horizontal. Pressure: 14 bar (203.1 psi). Temperature: -50 °C (-58 °F). Drive Type: AC motor through reducer. Agitation: Yes. Agitator Seal Type: Packing. Capacity in Gallons: 3,900 L (1,030 gallons).
Condition: Used
Material: Stainless Steel 316
Manufacturer: IPS
Evaporation Rate: 1,771 kg/h (3,905 lb/h)
Total Heat Transfer Surface Area: 72.6 m² (781 ft²)
Mixer is driving a two tier 316SS 3 blade agitator 54" span upper impeller, 42" span lower impeller. Mixer drive is Inverter duty.
Diameter: 2,743 mm (108 in). Height: 3,658 mm (144 in). Orientation: Vertical. Pressure: 0.97 bar (14 psi). Temperature: 121.1 °C (250 °F). Mechanical Seal on Shaft: Yes. Drive Type: Lightnin Model 16Q7.5. Internal Coil: Yes. Internal Coil Surface Area: 781. Agitation: Yes. Agitator Seal Type: Mechanical. Internal Coil or Jacket Pressure: 3.4 bar (50 psi). Capacity in Gallons: 21,955 L (5,800 gallons).
Condition: Used
Material: Stainless Steel 316
Manufacturer: IPS
Evaporation Rate: 1,771 kg/h (3,905 lb/h)
Total Heat Transfer Surface Area: 72.6 m² (781 ft²)
Mixer is driving a two tier 316SS 3 blade agitator 54" span upper impeller, 42" span lower impeller. Mixer drive is Inverter duty.
Diameter: 2,743 mm (108 in). Height: 3,658 mm (144 in). Orientation: Vertical. Pressure: 0.97 bar (14 psi). Temperature: 121.1 °C (250 °F). Mechanical Seal on Shaft: Yes. Drive Type: Lightnin Model 16Q7.5. Internal Coil: Yes. Internal Coil Surface Area: 781. Agitation: Yes. Agitator Seal Type: Mechanical. Internal Coil or Jacket Pressure: 3.4 bar (50 psi). Capacity in Gallons: 21,955 L (5,800 gallons).
Condition: Used
Material: Stainless Steel 316
Manufacturer: IPS
Evaporation Rate: 1,771 kg/h (3,905 lb/h)
Total Heat Transfer Surface Area: 72.6 m² (781 ft²)
Mixer is driving a two tier 316SS 3 blade agitator 54" span upper impeller, 42" span lower impeller. Mixer drive is Inverter duty.
Diameter: 2,743 mm (108 in). Height: 3,658 mm (144 in). Orientation: Vertical. Pressure: 0.97 bar (14 psi). Temperature: 121.1 °C (250 °F). Mechanical Seal on Shaft: Yes. Drive Type: Lightnin Model 16Q7.5. Internal Coil: Yes. Internal Coil Surface Area: 781. Agitation: Yes. Agitator Seal Type: Mechanical. Internal Coil or Jacket Pressure: 3.4 bar (50 psi). Capacity in Gallons: 21,955 L (5,800 gallons).
Condition: Used
Material: Stainless Steel 316
Manufacturer: IPS
Evaporation Rate: 1,771 kg/h (3,905 lb/h)
Total Heat Transfer Surface Area: 72.6 m² (781 ft²)
Mixer is driving a two tier 316SS 3 blade agitator 54" span upper impeller, 42" span lower impeller. Mixer drive is Inverter duty.
Diameter: 2,743 mm (108 in). Height: 3,658 mm (144 in). Orientation: Vertical. Pressure: 0.97 bar (14 psi). Temperature: 121.1 °C (250 °F). Mechanical Seal on Shaft: Yes. Drive Type: Lightnin Model 16Q7.5. Internal Coil: Yes. Internal Coil Surface Area: 781. Agitation: Yes. Agitator Seal Type: Mechanical. Internal Coil or Jacket Pressure: 3.4 bar (50 psi). Capacity in Gallons: 21,955 L (5,800 gallons).
Condition: Used
Material: Rubberlined
Clad: Yes
Evaporation Rate: 9,072 kg/h (20,000 lb/h)
Diameter: 4,877 mm (192 in)
CS, with rubber lining, Vapor Body, with Alloy support accessories, forced circulation crystallizer, part of a Zero Discharge System (ZLD). The system's major equipment consists of a shell and tube evaporator heater, Vapor body, recirculation pump and centrifuge. Rated for 50 GPM flow 10% moisture) and consumes 20 psi steam at 25,00 lbs./hr Following is a short process description: The feed from Brine Evaporator enters the recirculation piping above the recirculation pump. The feed is mixed with recirculating brine slurry and pumped through the heater where it increases in temperature and is sent to the vapor body. The hot brine flashes down to the saturation pressure inside the vessel, producing vapor and the cycle is repeated. Crystals are formed continuously in crystallizer vapor body and have to be removed. Concentrated product is removed from the system, passed through a centrifuge to remove the solid crystals and is returned to the evaporator recirculation line. The crystals are sent to a landfill. Vapor from the crystallizer is sent to a small barometric condenser using cooling water to condense the vapors. Condensate is mixed with incoming cooling water and is discharged back to the cooling tower. Vent from the condenser is vented by a CS ejector, through a silencer, and out to the atmosphere. Prime condensate from the condensed plant stream is sent back to the primary feed heater to assist in heating incoming Brine Evaporator feed. The following are main components of the system: Stock #228100- crystallizer heater is 5,700 Ft2 of surface area, with 1040 straight tubes, 1.25”OD x 0.028” wall thickness x 12 Feet long, and are constructed of Titanium. The tube sheets are SS316 Ti clad. Heads are made of SS alloy AL6XN & Shell of SS316L. The Crystallizer stock # 228156 is 16’ Dia. x 30’ Overall Height with 60” cone bottom. It is made of rubber lined Carbon steel. (the crystallizer vessel was removed , we have a drawing so a new vapor body can be constructed.) The Crystallizer recirculation pump, stock #228104 is 19,000 GPM with 150 HP motor and fabricated from SS alloy. The centrifuge stock #228101 is Bird Bowl type, 24" diameter x 38" long, rated for 18,304 Lbs./hr. with SS316L contact parts, 30 HP Motor with SS alloy product contact parts.
Condition: Used
Material: Stainless Steel 304
Evaporation Rate: 1,771 kg/h (3,905 lb/h)
Total Heat Transfer Surface Area: 72.6 m² (781 ft²)
Mixer is driving a two tier 3 blade 316SS agitator. Four full length welded side wall baffles.
Diameter: 2,743 mm (108 in). Height: 3,353 mm (132 in). Orientation: Vertical. Pressure: 0.97 bar (14 psi). Temperature: 121.1 °C (250 °F). Mechanical Seal on Shaft: Yes. Drive Type: Lightnin 16Q7.5. Agitation: Yes. Agitator Seal Type: Mechanical. Internal Coil or Jacket Pressure: 3.4 bar (50 psi). Capacity in Gallons: 21,577 L (5,700 gallons).