120results about "Evaporators with vertical tubes" patented technology

The present application relates to a kind of hot exciting flash evaporation loop lift heat exchanger, including upper head, lower head, cylinder, several heat exchange tubes, the upper end surface of cylinder and the upper head form cavity I between, the lower end surface of cylinder and the lower head form cavity II between, cavity I, cavity II and the inner cavity of cylinder are not communicated with each other between, heat exchange tube is fixed in the inside of cylinder by tube sheet, the upper end of heat exchange tube is placed in cavity I and is communicated with cavity I, lower end and cavity II are communicated, cylinder includes lift section cylinder and hot exciting section cylinder, heat exchange tube includes lift section heat exchange tube and hot exciting section heat exchange tube, lift section heat exchange tube and hot exciting section heat exchange tube are communicated by throttling component between, the inner diameter of throttling component is less than the inner diameter of hot exciting section heat exchange tube.The heat exchanger of the present application is provided with a kind of hot exciting flash evaporation loop lift, will hot exciting pressurization energy storage, throttling flash evaporation kinetic energy release, loop lift heat exchange and vapor-liquid separation function integration in same equipment, solve the problem of traditional lift section heat exchanger dependence big temperature difference.

The utility model discloses a vertical pipe efficient falling film evaporator, and belongs to the technical field of vertical pipe falling film evaporators.The vertical pipe efficient falling film evaporator comprises an evaporation mechanism, two sets of inserting rods are pressed, the two sets of inserting rods enter a mounting block, the mounting block is inserted into a mounting groove block, and the inserting rods are inserted into the mounting groove block under the action of spring bounce; the movable scraping plate is installed in the vertical pipe evaporator body through the installation block, the servo motor drives the connecting rod to rotate, the connecting rod drives the flow guide block and the connecting block to rotate, it can be guaranteed that material liquid is evenly discharged through the flow guide block, and the material liquid can be evenly discharged through the flow guide block. The connecting block drives the movable scraper to rotate, the material liquid can be evenly smeared, the inner wall of the vertical pipe evaporator body can be conveniently cleaned in the later period, the material liquid can be conveniently and evenly discharged and evenly smeared, mounting and dismounting are convenient, the evaporation and extraction efficiency is improved, operation is easy and fast, and using is convenient.

A hybrid process and system for separating water from an inlet brine solution is disclosed. The hybrid process couples at least two different separation processes / systems. The inlet brine solution is fed into a first separation process, which produces a water distillate and a brine concentrate. The brine concentrate from the first separation process is then fed into the second separation process to further recover additional water. The excess heat from the second separation process is supplied to the first separation process.

The invention relates to a process for obtaining free fatty acid and / or free fatty acid ester, in which a liquid mixture containing the free fatty acid and / or the fatty acid ester is separated by contacting a vapour of the liquid mixture in a column of a distillation apparatus with condensate formed from the vapour running downward, wherein heat and mass transfer takes place between the vapour and the condensate on column internals. According to the invention, the column has at least 10 theoretical plates and the separation is conducted with a pressure drop between the top and bottom of the column Δp of ≥ 3.3 mbar. Appropriately, the liquid mixture, preferably produced from vegetable oil or from fish oil, contains polyunsaturated fatty acid, preferably omega-6 or omega-3 fatty acid and / or alkyl monoesters and / or glycerol monoesters. In one configuration of the invention, the column has at least 30, preferably at least 40, theoretical plates and the separation is conducted with a pressure drop Δp between 3.5 mbar and 6 mbar.

The invention relates to a distillation unit (100 000) which is designed for a continuous distillation process and to a method for a continuous operation for separating a liquid substance mixture (10) into two to six liquid product flows (201, 202, . . . ) with different compositions and into a gaseous product flow (300). For this purpose, an evaporation unit (10 000) is provided consisting of multiple evaporation devices (10 000-1, 10 000-2, . . . ), wherein each evaporation device has a circuit device (1 200-1, 1 200-2, . . . ) for recirculating a sub-quantity of each of the liquid sump flows (22, 21, . . . ) of an evaporation device into the respective evaporation device, and each of the circuit devices additionally has a discharge device (1 300-1, 1 300-2, . . . ) for providing one of the liquid product flows (201, 202, . . . ).

This application provides an evaporation device and a heat exchange system, including an evaporation chamber, a heat absorption chamber, and a liquid storage chamber. A gas pipeline is connected to the evaporation chamber, and a liquid pipeline is provided with multiple liquid inlet pipes. Liquid inlet holes are provided on the walls of the liquid inlet pipes, and the liquid inlet pipes are connected to the liquid storage chamber. The liquid control mechanism includes a water suction plate and multiple sealing components. The water suction plate is disposed in the evaporation chamber, and one end of the sealing component is connected to the water suction plate, while the other end of the sealing component extends into the interior of the liquid inlet pipe. When the liquid in the evaporation chamber cannot evaporate in time, the sealing component blocks the liquid inlet holes of the liquid inlet pipe, controlling the flow rate of the liquid inlet pipe. This prevents excessive liquid accumulation in the evaporation chamber from affecting the steam discharge in the heat absorption tube, thereby improving the evaporation efficiency of the liquid. The liquid medium that the water suction plate cannot evaporate in time avoids blocking the inlet of the heat absorption tube assembly. Due to the increased weight of the water suction plate after absorbing liquid, it presses down on the sealing components, blocking part of the liquid inlet pipe, thereby reducing the liquid flow rate and improving the evaporation efficiency of the liquid medium.

The invention relates to the technical field of MVR (mechanical vapor recompression) evaporators, in particular to an anti-scaling enhanced heat transfer system of an MVR evaporator, which comprises an evaporator, a separator in pipeline communication with the evaporator and a compressor in pipeline communication with the separator, and the compressor and the output end of the evaporator are in pipeline communication with the evaporator; wherein the evaporator comprises a shell, an upper plate and a lower plate, the upper plate and the lower plate are rotationally connected into the shell, the multiple heat exchange pipes are connected in an overall rotating mode, steam is input into the shell through the compressor, an input port is formed in one side of the shell, and therefore the heat exchange pipes can be installed in a traditional fixed heat exchange pipe installation mode, and the heat exchange pipes can be installed more conveniently. Compared with the prior art, the heating uniformity of the heat exchange tube is general, and the heating uniformity of the heat exchange tube can be improved by adopting the mode that the heat exchange tube rotates circumferentially as a whole in the scheme, so that the heat transfer effect is enhanced; in addition, the arranged cleaning assembly can be used for flushing the heat exchange pipe, and therefore the durability and reliability of the whole device are improved.

The invention provides a method and a system for purifying 4-hydroxybutyl acrylate based on film evaporation coupled extractive distillation, a reaction solution obtained after esterification reaction of acrylic acid and 1, 4-butanediol is subjected to film evaporation to obtain light component acrylic acid and concentrated solution, and the concentrated solution comprises 1, 4-butanediol, 4-hydroxybutyl acrylate, 1, 4-butanediol, 1, 4-hydroxybutyl acrylate, 1, 4-butanediol, 1, 4-butanediol, 1, 4-butanediol, 1, 4-butanediol, 1, 4-butanediol, 1, 4-butanediol and 1, 4-butanediol. The preparation method comprises the following steps: adding 1, 4-butanediol diacrylate, an esterification reaction catalyst and a polymerization inhibitor; carrying out extractive distillation on the concentrated solution and an extractant ionic liquid to respectively obtain a product 4-hydroxybutyl acrylate and a post-reaction extractant; and rectifying the reacted extracting agent, recovering the extracting agent, and reusing the extracting agent for extractive distillation. By adopting thin film evaporation, the separation period can be effectively shortened, and the polymerization risk is reduced; extractive distillation not only shortens the separation period and reduces the risk of polymerization, but also the ionic liquid can break azeotropy among 1, 4-butanediol, 4-hydroxybutyl acrylate and 1, 4-butanediol diacrylate, the high-purity product 1, 4-butanediol is obtained through separation, and purification of 4-hydroxybutyl acrylate is achieved.

The invention relates to an evaporator-condenser-type heat exchanger comprising a plurality of zones, each zone comprising at least one extractor means configured to channel at least a portion of the primary vapor generated in said zone towards the outside of the heat exchanger. The heat exchanger includes a plurality of sub-assemblies consisting in part of a layer of a thermally conductive material.

To provide an improved vapor compression distillation system.SOLUTION: A distillation device comprises a source fluid input and an evaporator 6060 in fluid communication therewith. The device further comprises a compressor 6064 having an impeller coupled to a motor, the compressor having a low-pressure inlet for vapor from the evaporator and a high-pressure outlet for compressed vapor. The device further comprises a temperature sensor 6066 configured to monitor the temperature of the vapor in the inlet, and a condenser 6076 in heat transfer relationship with multiple exterior surfaces of the evaporator and in fluid communication with the compressor outlet. The device further comprises a controller 6034 configured to adjust a rotation speed of the impeller with an impeller motor command based on a calibrated motor speed for the distillation device. The controller is configured to determine an adjusted motor speed for a next use of the device and overwrite the calibrated motor speed with the adjusted motor speed.SELECTED DRAWING: Figure 2

The present invention provides a falling film evaporator based on the heat exchange tube enhanced heat transfer technology, which relates to the technical field of evaporation equipment, including an evaporation tank body, a feed pipe installed on the top of the evaporation tank body, a liquid separation plate provided inside the evaporation tank body, a liquid separator provided above the liquid separation plate, the liquid separator is connected to the feed pipe, a lower liquid plate is provided at the bottom of the liquid separator, a plurality of lower liquid holes are provided on the lower liquid plate, the liquid falling points of the lower liquid holes are arranged at equal intervals with the pipe openings of the adjacent heat exchange tubes, and the distance between each lower liquid hole and the liquid separation plate is the same, a float is provided in the liquid separator, a switch plate is rotatably installed in the liquid separator, a plurality of switch holes are opened on the switch plate, and a transmission mechanism is provided on the side of the liquid separator, the float is linked with the switch plate through the transmission mechanism, controls the flow resistance of the switch holes and the lower liquid holes, realizes uniform distribution of liquid and material, controls the synchronous opening and closing of the lower liquid holes, and realizes uniform distribution of liquid and material. This scheme realizes uniform distribution of liquid and material, so that the film forming conditions in the heat exchange tubes at different positions are as similar as possible.

In one aspect, a mass exchanger having an air inlet, air outlet, airflow generator, and a tubular membrane assembly. The tubular membrane assembly includes an inlet header, an outlet header, and a plurality of tubular membranes. The tubular membranes have side walls configured to facilitate mass transfer between air contacting the tubular membranes and working fluid in the tubular membranes. The inlet header includes an inlet header body having inlet header body openings with inlet end portions of the tubular membranes extending in the inlet header body openings and inlet header potting connecting the inlet end portions of the tubular membranes to the header body. The outlet header includes an outlet header body having outlet header body openings with outlet end portions of the tubular membranes extending in the outlet header body openings and outlet header potting connecting the outlet end portions of the tubular membranes to the header body.

To provide an improved vapor compression distillation system.SOLUTION: The distillation device comprising a raw fluid input and an evaporator 6060 in fluid communication therewith, the device further comprising a compressor 6064 having an impeller coupled to a motor, the compressor having a low pressure inlet for vapor from the evaporator and a high pressure outlet for compressed vapor, the device further comprising a temperature sensor 6066 monitoring the temperature of the vapor at the inlet, and a condenser 6076 in heat transfer relationship with a plurality of external surfaces of the evaporator and in fluid communication with the outlet of the compressor; The device further comprises a controller 6034 for adjusting the rotational speed of the impeller with an impeller motor command based on a calibrated motor speed for the distillation device, wherein the controller is configured to determine an adjusted motor speed for a next device use and overwrite the calibrated motor speed with the adjusted motor speed.SELECTED DRAWING: Figure 2

This disclosure provides a bottom chamber of a stripper (or bottom reservoir) including an anti-vortex device, a baffle, and a guide vane. This disclosure further provides a stripper, a urea HP stripper, a urea unit, a method of operating the stripper, and a method of producing a composition based on solid particulate urea.

The invention discloses a pipe and plate combined triple-effect countercurrent 32-50% caustic soda evaporation process and device, and belongs to the field of caustic soda production, the pipe and plate combined triple-effect countercurrent 32-50% caustic soda evaporation device comprises an evaporation unit, a heat exchange unit, a condensate water recovery unit and a vacuum unit; the evaporation unit comprises a first-effect tubular falling film evaporator, a matched first-effect separation chamber, a second-effect plate-type evaporator, a matched second-effect separation chamber, a third-effect plate-type evaporator, a matched third-effect separation chamber and a surface condenser; new steam is introduced into a shell pass of a heating chamber of the first-effect tubular falling film evaporator, a secondary steam outlet of the first-effect separation chamber is connected with a heating side inlet of the second-effect plate-type evaporator, a secondary steam outlet of the second-effect separation chamber is connected with a heating side inlet of the third-effect plate-type evaporator, and a secondary steam outlet of the third-effect separation chamber is connected with the surface condenser. The device has the effects of improving the heat energy utilization efficiency and reducing the energy consumption.

The embodiment of the invention relates to the technical field of evaporators, in particular to a liquid separation structure suitable for a micro-channel evaporator and the evaporator with the liquid separation structure. The liquid separation structure comprises a liquid blocking part which is used for blocking the upper portion of an inlet of each vertical micro-channel pipe and preventing a working medium from entering the inlet of each vertical micro-channel through the upper portion of the liquid blocking part. The structure further comprises a drainage part which is connected with the liquid blocking part and used for guiding the working medium at the liquid blocking part to flow to the bottom of the collecting pipe. In addition, the structure further comprises a liquid inlet space, and a space formed below the liquid blocking part is surrounded by the drainage part and the liquid blocking part, so that the working medium accumulated at the bottom of the collecting pipe can overflow inlets of the vertical micro-channels exposed in the liquid inlet space through the liquid inlet space. The liquid distribution structure can uniformly distribute a working medium entering the sealed collecting pipe into a plurality of vertical micro-channel pipes which are inserted into the bottom of the collecting pipe side by side in a sealed manner.

The present application provides a kind of black liquor seed crystal concentration evaporator, including outer flow pipe type falling film concentration evaporator unit, black liquor seed crystal mixing and steam separator.Outer flow pipe type falling film concentration evaporator unit includes medium-pressure steam inlet box, black liquor liquid inlet flow guide film forming box, black liquor outer flow falling film evaporation box and condensate and non-condensable gas discharge box.Outer flow pipe type falling film concentration evaporator unit is connected with black liquor seed crystal mixing and steam separator by concentration black liquor discharge pipe.Black liquor seed crystal mixing and steam separator.Due to the modular design of outer flow pipe type falling film concentration evaporator unit, different black liquor processing capacity can be connected with black liquor seed crystal mixing and steam separator by pipeline through multiple units to realize.

The application relates to the field of wastewater treatment, and particularly discloses a forced circulation evaporator which comprises a heating chamber, a wastewater storage tank arranged at one side of the heating chamber, a lower circulation pipe arranged at the lower ends of the heating chamber and the wastewater storage tank, a circulation pump arranged at one end of the lower circulation pipe, and an upper circulation pipe arranged at the upper ends of the heating chamber and the wastewater storage tank, wherein the heating chamber is provided with a heating mechanism, the heating mechanism comprises a vertical shaft rotatably connected to the middle part of the heating chamber, and the side walls of the vertical shaft are uniformly and circumferentially provided with heating plates; and the inner side of the heating chamber is provided with a water pressure cleaning mechanism for cleaning the heating plates. The forced circulation evaporator is rotatably arranged in the heating chamber through the arranged heating mechanism, which helps to reduce the temperature gradient in the liquid, improve the uniformity of heating, facilitate the subsequent evaporation and crystallization of the wastewater storage tank, and realize the evaporation of the wastewater in a forced circulation mode, so that the efficiency is high and the effect is good.

The invention discloses a silicon carbide film evaporator, and relates to the field of evaporators, the silicon carbide film evaporator comprises a shell and a tube plate arranged in the shell, an evaporation tube is arranged on the tube plate, and a distance plate is further arranged in the shell; a distance fixing plate is arranged on the evaporation pipe, a film distributor is arranged on the distance fixing plate in a sliding mode, part of the film distributor extends into the evaporation pipe, an inclined section is arranged in the evaporation pipe, a gap allowing a liquid film to pass through is formed between the film distributor and the inclined section, and the size of the gap is adjusted based on the distance between the film distributor and the inclined section. According to the silicon carbide film evaporator, when the injection amount of liquid is small, the film distributor is controlled to be close to the inclined section, and at the moment, the gap becomes small, and when the injection amount of the liquid is large, the film distributor is controlled to be away from the inclined section, and at the moment, the gap becomes large, so that the film distributor can adapt to liquid with different injection amounts.

A separation system separates a first liquid from a composite liquid. Examples of the composite liquid are seawater, brine, rainwater, wastewater, a biofuel precursor, lactic acid, or juice. The plate heat exchanger includes at least one evaporation channel and at least one condensation channel. The composite liquid flows through the evaporation channel, wherein the first liquid evaporates from the composite liquid into the gas. The direct heat exchanger also vaporizes the first liquid into the gas. The gas flows from the direct heat exchanger through a condensation channel, where the first liquid condenses and thereby separates from the composite liquid.

The utility model relates to the technical field of low-temperature evaporators, in particular to a detachable pipeline for a low-temperature evaporator, which comprises a liquid adding part and an evaporating pot, the liquid adding part comprises a bottom shell, the top end of the bottom shell is opened, a splitter plate is horizontally fixed in the bottom shell, and a plurality of evaporating pipes are uniformly and vertically assembled on the top surface of the splitter plate in a communicated manner; the bottom end of the evaporation tank is opened, the evaporation tank is detachably communicated and assembled with the top end of the bottom shell, a steam inlet pipe is horizontally communicated and fixed to the upper side of the outer wall of the evaporation tank, a steam exhaust pipe is horizontally communicated and fixed to the lower side of the outer wall of the evaporation tank, and a liquid adding pipe is vertically communicated and fixed to the bottom surface of the bottom shell; and a liquid discharge pipe is vertically communicated and fixed on the top surface of the evaporation tank. When the low-temperature evaporator is used, evaporation liquid is heated and evaporated in the pipeline, evaporation solid impurities remain in the pipeline in the heating and evaporation process, in order to clean the impurities, the wall of the pipeline becomes thick, the heat conduction efficiency of the evaporation pipeline is improved, and the conversion efficiency of the low-temperature evaporator is guaranteed.

The application relates to an MVR system based on a heat shock flash evaporation loop lift heat exchange, which comprises a lift heat exchanger, a vapor-liquid separator, a preheater, a heat shock heater and a throttling component, the preheater is communicated with the heat shock heater, the condensate inlet of the preheater is communicated with the condensate outlet of the lift heat exchanger; the material outlet of the heat shock heater is communicated with the feed inlet of the lift heat exchanger through the throttling component; the lift heat exchanger is communicated with the vapor-liquid separator, so that the secondary steam in the lift heat exchanger enters the vapor-liquid separator, the gaseous phase after separation is compressed and introduced into the lift heat exchanger, and is used as a heat source of the lift heat exchanger; the concentrated liquid flowing out of the vapor-liquid separator and the lift heat exchanger is extracted when the concentration detection is qualified, and is re-injected into the heat shock heater after being pressurized for reuse when the concentration detection is unqualified. The application can form a stable circular flow without relying on a large temperature difference, matches the narrow temperature difference heat transfer characteristics of the MVR system, and greatly reduces the high-grade energy consumption of the lift heat exchanger.

A hot-pressing type pure steam generator relates to the technical field of pure steam generators and comprises an evaporator, a compressor, a buffer tank, a steam-water separator, a stock solution inlet pipe and three heat exchangers. A stock solution inlet pipe, a stock solution pipeline of the first heat exchanger, a stock solution pipeline of the second heat exchanger, a stock solution pipeline of the third heat exchanger and a first liquid inlet of the buffer tank are sequentially communicated; a second liquid inlet of the buffer tank is communicated with a stock solution outlet of the evaporator; a liquid outlet of the buffer tank is communicated with a stock solution inlet of the evaporator; a non-condensable gas outlet of the evaporator is communicated with a heating medium pipeline of the first heat exchanger, and a steam condensate outlet of the evaporator is communicated with a heating medium pipeline of the second heat exchanger; a steam outlet of the evaporator is communicated with the steam-water separator through the compressor and outputs pure steam, and a liquid outlet of the steam-water separator is communicated with a heating medium pipeline of the third heat exchanger. The invention provides a hot-pressing type pure steam generator. The technical problems that in the prior art, energy consumption is large, and the operation cost is high are solved.

Embodiments of the invention provide systems and methods for water treatment and / or desalination.

The invention relates to the technical field of chemical equipment, and particularly discloses a methanol vaporization system for chloromethane synthesis, a process control method and application. The system comprises a vertical vaporization cavity, a silicon carbide tube nest circulating reboiler, a flexible connection part and a safety control system. A vertical thermosyphon circulation loop is formed between the vertical vaporization cavity and the silicon carbide reboiler through a connecting pipeline; the flexible connecting part is arranged on the connecting pipeline to buffer vibration; the safety control system comprises a methanol concentration monitor and a remote stop valve and is used for achieving rapid isolation during leakage. The process control method of the system comprises the steps of safety monitoring, quick response and automatic heat source switching. Efficient heat transfer (the total heat transfer coefficient is 450-550 W / (m.K)) is achieved through the vertical thermosyphon structure, the problem of vibration fracture of the silicon carbide pipe is solved through the flexible connection component, and the reliability, energy efficiency and intrinsic safety level of equipment are remarkably improved through the design that the response is fast within 3 seconds or less and the static reserve is low within 1000 liters or less.

Described is a process comprising a step of evaporating glycerol in single chamber evaporator for purifying glycerol and / or for providing gaseous glycerol for chemical conversion into one or more reaction products.

The invention relates to the field of evaporators, in particular to an efficient heat exchange evaporator. Comprising a shell; a first partition plate and a second partition plate are fixedly connected in the shell; a plurality of heat exchange pipes are fixedly connected between the first partition plate and the second partition plate. According to the invention, the cooling liquid in the cavity is squeezed into the heat exchange groove, so that all the cooling liquid can exchange heat with the heat exchange pipe through the smaller heat exchange groove, and the problem that the cooling cavity of the existing evaporator is mostly of an integral structure, so that the cooling liquid far away from the heat exchange pipe area cannot exchange heat fully and is directly discharged out of the cooling cavity is solved; a sliding plate and a wiping ring are driven to move up and down through a first electric push rod, and then dirt attached to the outer wall of the heat exchange tube is wiped and scraped through bristles on the inner ring of the wiping ring; a second electric push rod drives a fixing plate, a sliding rod and a scraper to move up and down, dirt on the inner wall of the heat exchange tube is wiped and scraped through the scraper, and the problem that the dirt adheres to the inner wall and the outer wall after the heat exchange tube is used for a long time, and the heat exchange efficiency is affected is solved.

This disclosure provides a baffle plate for a shell-and-tube heat exchanger. The baffle plate includes a flat plate having a region comprising a plurality of annular elements designed to receive tubes from the shell-and-tube heat exchanger. The annular elements are arranged in at least two rows, wherein the rows are staggered relative to adjacent rows. The outer diameter of each annular element is less than 130% of its inner diameter, and each annular element engages with all its adjacent annular elements via a bridging structure oriented along a line connecting the centers of two adjacent annular elements in the plane of the plate, thereby defining a plurality of openings in the plate. This disclosure also provides: a shell-and-tube heat exchanger; a method for heating a liquid composition; a method for stripping a liquid composition comprising urea, carbamate, ammonia, and water; and a method for producing a solid particulate urea-based composition.

The invention discloses a liquid distributor and a falling film head for a falling film evaporator. The liquid distributor comprises a liquid inlet distribution mechanism, a heat exchange mechanism and a collecting and discharging mechanism, the heat exchange mechanism comprises a heating cylinder, two tube plates, a plurality of heat exchange tubes and a plurality of falling film heads, the tube plates are fixedly connected to the inner walls of the upper end and the lower end of the heating cylinder, the upper ends and the lower ends of the heat exchange tubes penetrate through the tube plates at the upper ends and the lower ends correspondingly, and the falling film heads are horizontally arranged and fixedly installed at the upper ends of the heat exchange tubes in a one-to-one correspondence mode. Tangential notches parallel to the center line of the heat exchange tube are symmetrically formed in the two sides of the falling film head. The liquid inlet distribution mechanism is provided with a liquid distributor and comprises a distribution cone, a drainage cylinder and an unpowered flow dividing assembly, and the flow dividing assembly evenly disperses liquid to the surface of the tube plate through rotation of a flow dividing paddle. By optimizing the distribution structure and the flowing mode, the problems of wall drying, splashing, scaling and the like caused by uneven liquid distribution and out-of-control flow speed in the prior art are solved, and the uniformity and the heat transfer efficiency of a liquid film are improved.