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I. Introduction
By the factory manufacturing the Z series of rotary scraper film evaporator is a film by rotating the scraper force can be carried out under vacuum evaporation of falling film evaporator of new and efficient. It is heat transfer coefficient, evaporation, high strength, short time overcurrent, operating flexibility, in particular, heat-sensitive materials suitable for high viscosity materials and materials containing particles crystallize evaporation, degassing solvent removal, distillation. Therefore, in chemical, petrochemical, pharmaceutical, pesticide, cosmetic, food, fine chemical industry widely applied. 
Our factory has been manufacturing such equipment more than ten years, has accumulated rich experience in manufacture and use. Over the years, according to market demand closely the user's actual production to meet the technological requirements of the users premise of rational choice suitable device structure, Bao Zheng reliable manufacturing superior quality, tooling equipment, detection means and product design and other aspects improving and becoming more perfect, has made impressive achievements, technical level and product quality in the domestic leading level office.
Second, the structural characteristics
Z Series film evaporator and the main structure shown in Figure 1, the structural parts are as follows:
1. Motor, reducer
It is the drive rotor. The rotational speed of the rotor will play depends on the form of scraper. The material viscosity and evaporation Flashlight diameter; select the appropriate speed scraper is to ensure stable and reliable operation of the evaporator and the satisfaction one of the important parameters evaporation effect.
2. Separation tube
Material separated from the body of the barrels in the bottom of the tangential entry into the evaporator, and were installed within the fabric in the separation Flashlight device is continuously uniformly distributed in the inner wall evaporation, evaporation from the evaporating body of the barrels out of steam rose to the second separation cartridges, including installation of gas-liquid separator, the second steam-carrying droplets or bubbles may separate, secondary steam from the top of the exit leads to the evaporator.
Based on the calculation of resistance of the evaporator Flashlight rational design of separation is to avoid  material "short" one of the key factors. (So-called "short circuit" means material he first entered the evaporator, evaporation process has not been completed, exit from the secondary steam evaporator.)
3. FEEDER
Fabric installed in the rotor. Rational design, the evaporator from the tangent direction to the material, by rotating the fabric device, is continuously poured evenly was announced in the evaporation of surface membrane.
4. Accumulator
Vane-type gas-liquid separator installed in the separation tube top, it will also mix up the secondary steam droplets or bubbles may trap and make it back to the evaporation surface.
5. Evaporative Flashlight
Also known as heat Flashlight. It was compulsory rotating scraper film clip kit of materials and heating medium for heat exchange in the evaporation surface. The diameter and length Flashlight evaporation from the evaporation area and determine the appropriate aspect ratio.
Heated inner wall by special machining and polishing, and with both ends of the flange face a process which would ensure the equipment as a whole center of the circle degrees. Polished (if necessary, mirror polished) and smooth clean inner wall light, sticky materials and scale, the equipment effectively to ensure high heat transfer coefficient.
5.1 If the heating medium is steam, heating Flashlight generally use the jacket form.
5.2 If the heating medium or high pressure steam for the heat-conducting oil, the heating body of the barrels commonly used form of half-pipe.
6. Rotor
Evaporator tube installed in the body of the rotor shaft and the transfer from the frame. Rotor by the motor, gear drive, and driving scraper in circular motion. Transfer frame made of stainless steel, plastic processing, its intensity, geometry, stability, and so are effectively guaranteed
7. Scraper
 As the scraper movement of the material constantly evaporating into the thin film scratch the surface in order to achieve the effect of thin film evaporation.
According to the viscosity and other properties of materials, with the following four types of scraper forms are available:
(1) Slide scraper (see Figure 2)
Slide scraper is the most basic and common form of scraper. Scraper is installed in the four scraper rotor guide slots, the centrifugal force due to the role of rotor radial Shuaixiang evaporation tube inside wall, while in circular motion along with the rotor. This scraper scraping action, so that materials in the evaporation of the membranous wall on the turbulent state was greatly enhanced heat transfer coefficient, while such a continuous scraping action, effectively inhibit overheating of materials, such as dry wall and scaling phenomenon.
Typically, the scraper with PTFE material, it is suitable for operating temperatures below 150 ℃; when the evaporating temperature higher than 150 ℃, requires the use of carbon fiber material. Drag the end there was a certain point of processing the lead sump.
(2) fixed scraper (see Figure 3)
Fixed scraper are used metallic materials, it is rigid connections in the rotor, the length of scraper Flashlight with evaporation, rotary evaporation inner wall scraper with a gap of only 1-2mm, demanding precision machining and installation, It is suitable for ultra-high viscosity and easy to evaporation from the foam material, removing solvent or purification.
(3) hinged scraper (see Figure 4)
This scraper is suitable for easily scaling in the heating surface material, usually nonmetallic scraper, with scraper activities will hinge switch installed in the rack. When the rotor rotation, due to centrifugal force, scraper is pressed in the evaporation tube wall, (and the wall) at an angle in the wall slide, scrape the material into a film, and the wall to prevent scaling.
(3) spiral scraper (see Figure 5)
The scraper is applied to poor mobility, easy to scale, particularly the concentration of high viscosity materials.  When the rotor rotates through the thrust spiral scraper to smooth downward flow of condensed materials.
8. Bottom Head
Individually designed W-type bottom head, and configure the high-temperature self-lubricating bearings, both for the material of the material, while the end bearings to facilitate the maintenance and repair.
Third, performance characteristics
Film evaporator has the following unique advantages, conventional film evaporator and that is:
1. Minimal pressure loss in the rotary scraper film evaporator, the material "flow" and the secondary steam "flow" are two separate "channels": material along the evaporator tube wall (mandatory membrane) falling film down; and by the evaporation of surface evaporation from the secondary steam from the central cylinder of space almost unimpeded from the evaporator, the pressure loss (or pressure drop) is very small. End
2. Can be a real operating under vacuum conditions
Precisely because of secondary steam from the evaporator to the condenser surface resistance is extremely small, so make the whole surface evaporation evaporation tube wall to maintain a high vacuum (up to-750mmHg above), almost equal to the export of vacuum vacuum system. As the vacuum increase, effectively reducing the boiling point of the material being processed.
3. High heat transfer coefficient, high evaporation intensity
Lower boiling point materials, increases the temperature difference and heat medium; was turbulent state of the film, reducing the thermal resistance; Similarly, inhibition of coke material in the wall, scaling, and improved sub-evaporation tube wall heat transfer coefficient; Efficient rotary film evaporator overall heat transfer coefficient up to 8000KJ / h · ㎡ · ℃, so the evaporation intensity is high.
4. Low temperature evaporation
As the evaporation of the cylinder body to maintain a high vacuum, the boiling point materials to be processed significantly reduced, so heat-sensitive materials suitable for low temperature evaporation.
5. Overcurrent short time
Material in the evaporator over-current is very short, less than 10 seconds; for common activities scraper, the end of its scraping animal materials have diversion trench (see Figure 6), the angle is usually 45 °, changing the angle of perspective, can change the flow of materials over time, the material in the scraper scraping action under section spiral down from evaporation. Reduce the over-current time, to effectively prevent the evaporation process of the product decomposition, aggregation or deterioration.
6. Can make use of low-grade steam
Steam is used heat medium, the boiling point due to the reduction of the material, ensuring the same condition Δt, can reduce the heating medium temperature, using low-grade steam is beneficial to energy utilization. Especially suitable as a multi-effect evaporation of the end-effect evaporator.
7. Adaptable, easy to operate
Unique structural design, so the product can be difficult to deal with some conventional evaporator handle high viscosity, including particles, heat-sensitive and easy to crystallize the material.
Rotary film evaporator operating flexibility, stable operating conditions, and the maintenance workload is small, and easy maintenance.
Fourth, product specifications
Note: 1. Steamed area can be made according to the standard available from 0.1m2-40m2, and the special requirements of the user design.
2. Can be based on different technical requirements, select the appropriate form of scraper.
3. Master cylinder (with the material contact parts) and the jacket material and according to the actual needs of users, using carbon steel, sus304, 316L, 356Ti, 310S, or of titanium, nickel material, enamel and so on.
5, application industry and the operation unit sample
Efficient rotary film evaporator has been widely used in medicine, pesticides, light industry, daily chemical, biological chemistry, fine chemical, petrochemical and other fields, and received good results. See table below for reference.
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On the main application form and the typical bill of material unemployed:
Thin film evaporator can be used as enrichment materials, degassing, removing solvent (solvent recovery), purification and other chemical unit operations, the following process for reference:
1, material concentration (evaporation of water) Figure (8)
2, solvent removal or purification see Figure (9)
3, as a distillation column reboiler, see Figure (10A, B)
4, and tube evaporator form a multi-effect evaporator, Figure (11)
5. And short-range multi-stage distillation distiller component, see Figure (12)
6, thin film evaporator Selection Guide
Selection of thin film evaporator should be taken into account various factors, and these factors is interrelated, it generally takes to consider:
1. Evaporative area to determine:
▲ evaporation calculation, according to capacity and enter. The feed concentration, to calculate the evaporation rate per unit time (Kg / h);
▲ according to material viscosity, concentration, evaporation temperature, evaporation intensity estimation of the evaporator;
▲ consider some surplus capacity, calculate the required evaporation area.
2. To determine the degree of vacuum
▲ vacuum access is the cost of energy consumption, as long as meet the evaporative demand without requiring high vacuum;
▲ based on heat-sensitive materials, estimate the temperature in the vacuum evaporation;
▲ some leakage may be considered, and the secondary steam flow resistance, determine the required degree of vacuum;
3. Scraper forms and materials to determine
▲ according to the viscosity of materials, crystal orientation, foam and other physical and chemical properties, select the appropriate scraper form, taking into account the evaporation temperature, determine the appropriate material;
4. Determination of thermal media
▲ according to the required evaporation temperature and the heat consumption to determine the use of steam or hot water or thermal oil heat such as a an appropriate medium.
5. Evaporator selection of materials to determine
6. Explosion-proof motor performance and to determine the choice of
Our many years of experience in application of product would fully assist clients to make the right product selection.
Note: "a small prototype, welcome customers to test materials"
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