Liquid Ring Vacuum Pump In Ceramic Vacuum Filter

Precision ceramic vacuum filter integrates electromechanical, microporous ceramics and ultrasonic technology. It relies on the suction and capillary action of liquid ring vacuum pump to realize solid-liquid separation. It is widely used in mining, metallurgy, chemical industry, environmental protection and other industries.

Precision ceramic vacuum filter features:

۱٫ High vacuum (vacuum 0.09-0.098 MPa), low moisture filter cake.

۲٫ The solid content of filtrate is less than 50 ppm. It can be reused to reduce emissions.

۳٫ Compared with the traditional filter equipment, the energy consumption can be saved by more than 90%, the energy consumption is low and the operation cost is low.

۴٫ Compared with traditional ceramic filters, filter cake washing is added, which is suitable for washing materials.

۵٫ The use of PLC and computer combined with automatic valve control, high degree of automation, reduce labor intensity.

۶٫ Compact structure, small area, easy installation and maintenance. Liquid Ring Vacuum Pump in Ceramic Vacuum Filter

۷٫ The advanced drainage system can be used under any working conditions.

Precision Ceramic Vacuum Filter Principle :

Slurry suction zone: When working, the filter plate immersed in the slurry is combined with vacuum pressure under capillary action, and the surface is adsorbed into a layer of filter cake. The filtrate enters the distribution valve through the filter plate to the drainage tank.

Leaching area: After the filter cake is turned out of the slurry hopper, the filter cake is sprayed and washed.

Drying zone: The filter cake continues to dehydrate under the action of high vacuum force of water ring vacuum pump.

Discharging area: In the absence of vacuum, the scraper discharges automatically.

Backwashing: Industrial water or filtrate enters the ceramic plate through a distribution valve and is cleaned from inside to outside. Clean the blocked micropore. After a period of using the ceramic plate, the ceramic plate can be cleaned by the combination of ultrasonic wave and low concentration acid in order to keep the high efficiency of using the ceramic plate.

Effect diagram of ceramic filter:

Main components: filter board, main engine, air-water mixed constant pressure backwashing system, control system.

liquid ring vacuum pump Application :

At present, liquid ring vacuum pump has been widely used in the dewatering of non-ferrous metals, rare metals, ferrous metals, non-metallic concentrates and tailings in mines, oxides, electrolytic slag, leaching slag, dewatering of slag and acid treatment of waste sewage sludge in chemical industry. Material fineness ranges from – ۲۰۰ to – ۴۵۰ meshes and various superfine materials.

vacuum pump For Brick And Ceramic Industry

With the continuous improvement of people’s living standards, people’s decorative requirements for building ceramics are also getting higher and higher. People especially like the style of natural marble stone in places such as home furnishing. However, if marble and other materials are used to make bricks for laying, no matter in material mining or brick manufacturing, more human and material resources are consumed , expensive.

At the same time, due to the increasingly fierce competition in the construction ceramic market, in order to expand market share, manufacturers have invested more in high-tech products (such as the current underglaze color glazed tiles, ink-jet printing and other secondary firing microcrystalline composite tiles) while reducing costs and increasing product designs. The technology of this product is relatively mature, but the production cost is still high, and the finished product can not reach To stone texture or bump effect. Therefore, how to produce a kind of ceramic tile with low production cost and revolutionary breakthrough in pattern texture, material and production technology is a hot issue in the construction ceramics industry.

In the production of bricks, roofing tiles, porcelain and industrial ceramics, the important sign of quality is that there is no cavitation products. After firing, ceramics containing such cavities may be destroyed in the kiln, in extreme cases even the entire batch. In bricks, this quality defect usually takes years to appear; in winter, water seeps into the pores of the surface and breaks them.

pump-for-brick-and-ceramic-industry

Vacuum is the main component of ceramic processing. Especially in mixers and extruders, vacuum technology can Degas clay compounds, thus eliminating air inclusions in the pressing / extrusion stage, thus ensuring the molding products with almost no pores. This also greatly improves their dimensional stability, avoids the deformation before drying, and ensures the accurate dimensional accuracy of the finished product.

After loading the brick clay into the extruder, the vacuum is used to remove the air, thus preventing cavitation and subsequent brick cracking. Similar to brick clay, ceramic clay is first put into the mixer and pressurized with water or steam to form a uniform mixture. It is then transferred to the extruder and pressed into the die under high pressure. The material is then extruded to a suitable length, dried and fired.

Vacuum smelting, brick, ceramic manufacturing industry vacuum technology for metallurgy, brick and ceramic industry is a very important part. It can be used to prevent metal from being oxidized due to high temperature during processing. The water and air in the bricks and ceramics are evacuated by vacuum to ensure the quality they have.

Applicable products: slide valve vacuum pump series, rotary vane vacuum pump series, vacuum unit, water ring vacuum pump series.

Oil lubricated rotary vane vacuum pump has been put into use in such applications. Now, a new clay degassing system named is introduced, which is designed in close cooperation with the brick factory. The core component of the vacuum system is a dry rotary vane vacuum pump. It compresses the air and water vapor it takes in without oil or water. The system is equipped with filter, water cooling and control system, with two sizes.

Presentation on theme: “Modern Devices: Chapter 4 – Vacuum Systems”— Presentation transcript:

۱ Modern Devices: Chapter 4 – Vacuum Systems
Modern Devices: The Simple Physics of Sophisticated TechnologyCopyright © John Wiley and Sons, Inc.Chapter 4 – Vacuum SystemsEnabling High-Tech IndustriesModern Devices:The Simple Physics of Sophisticated TechnologybyCharles L. Joseph and Santiago Bernal

۲ Vacuum Chamber Technology
Modern Devices: The Simple Physics of Sophisticated TechnologyCopyright © John Wiley and Sons, Inc.Fig. 4.1 A large floor-standing vacuum chamber. At the left is an ion vacuum gauge (top) and valve with rubber hose to roughing pump (bottom). Numerous access ports (electrical feedthroughs, window ports, and blanks) are shown on the circumference. A cryopump is shown attached underneath chamber.Vacuum technology is needed for a wide variety of advanced instrumentation and manufacturing methods. Creating a vacuum is simply a matter of pumping the gasses out of a sealed container, known as a chamber or tank. Ultimately, the achievable level of vacuum is set by the pumping speed compared to the residual leak rate.Vacuum chambers come in all shapes and sizes. Most have various ports to feedthrough electrical signals or to manipulate mechanically items inside the chamber.Vacuum Chamber Technology

۳ Operating ranges of pumps and gauges
Modern Devices: The Simple Physics of Sophisticated TechnologyCopyright © John Wiley and Sons, Inc.Figure 4.2 The normal operating ranges of various type of pumps (red) and gauges (blue). The three classifications of vacuum are shown at the top.Operating ranges of pumps and gaugesUHVHigh Vac.Rough VacuumVenturi PumpMechanical PumpSorption PumpThermocouple GaugeDiffusion PumpTurbomolecularCryopumpIon PumpUHV Ion Gauge (hot filament)Pressure (Torr)

۴ Vacuum Chamber Technology
Modern Devices: The Simple Physics of Sophisticated TechnologyCopyright © John Wiley and Sons, Inc.Fig. 4.3 Cross-sectional diagrams of the two type of vacuum sealing mechanisms. The sealing surfaces as depicted are on the top and bottom surfaces. The groove must be wide enough to allow the O-ring to deform, making a seal. For a gasket, the harder knife-edge flange cuts a sealing grove into the softer gasket material.Hallow tube to establish a sealed volume between vacuum componentsASA-style sealTop and bottom O-ring vacuum sealing pointsConflat SealSeal by cutting intocopper gasketThere are two basic types of seals used for connecting two vacuum tank pieces together: 1) rubber or Viton O-rings pinched between two metal surfaces and 2) copper or silver-plated copper gaskets sandwiched between two surfaces with hard knife edges. Ultrahigh vacuums (UHV) can only be achieved with metal gasket seals. UHV chambers that do have O-rings, those portions are isolated from the main chamber via a UHV valve.Vacuum Chamber Technology

۵ Vacuum Chamber Technology
Modern Devices: The Simple Physics of Sophisticated TechnologyCopyright © John Wiley and Sons, Inc.Figure 4.4 An assortment of O-rings and copper gaskets along with a flanges. One feedthrough flange with three electrical connectors is shown at top center.Vacuum Chamber TechnologyThere are several standard configurations for O-rings and gaskets, as well as a number of vacuum quick-connection flange systems. For simplicity, the ASA O-ring and the CF Conflat gasket systems are shown in several sizes.O-rings can be reused many times, but copper gaskets are generally used only once. Copper gaskets, however, remain excellent seals for years if undisturbed.

۶ Physics of some vacuum gauges
Modern Devices: The Simple Physics of Sophisticated TechnologyCopyright © John Wiley and Sons, Inc.Thermocouple JunctionHeatedFilamentHallow Pipe toVacuum ChamberElectricalContactsi2 i1Physics of some vacuum gaugesThe physics behind a TC can be understood in terms of the responses of various metal alloys to temperature. When two ends of a wire are held at two different temperatures, a small voltage potential of a few millivolt (mV) is observed between the two ends. If two wires of different alloys are subjected to the same temperature disparity, one will have a slightly higher voltage than the other. A thermocouple junction is created if the two ends are connected together and share a common DT.This device is transformed into a vacuum pressure measurement by continually adding a fixed amount of heat via the filament. The amount of residual gas in the chamber impacts the amount of convective cooling and in turn, determines the equilibrium temperature at the TC junction end. The net current flowing through the TC measures the pressure.A thermocouple (TC) gauge is perhaps the most widely used since its operating range starts at the limits of mechanical vacuum gauges and ends at the crossover pressures for starting most HV or UHV pumps.Figure 4.5 The anatomy of a thermocouple (TC) gauge. The interior volume of the gauge has the same vacuum as the chamber, usually being connected through a hallow pipe (right) with a threaded end. The resistance of the TC is set by rate of cooling, which is proportional to the amount of residual gas.

۷ Physics of some vacuum gauges
Modern Devices: The Simple Physics of Sophisticated TechnologyCopyright © John Wiley and Sons, Inc.Ion collectorThermionicEmissionFilamentHallow metaltube to vacuumGlassTubeGridFigure 4.6 A hot cathode ion gage functions by passing a current and resulting voltage drop through a resistive material that heats up, emitting electrons into the vacuum. A series of rings connected to the positive volt side of the DC voltage, accelerating the free electrons towards the center. While these rings collect some electrons, many pass through, ionizing the residual gas. The current between the ion collector and the grid is proportional to the residual pressure.Physics of some vacuum gaugesThe UHV sensor of choice is the hot cathode ion gauge. The voltage across the resistive hot filament is typically 30 Vdc and generates a 10 mA (0.01 Amps) current of thermionic free electrons. These free electrons are attracted towards the grid, which biased at approximately +150 to +200 Vdc.While hot cathode ionization gauges have linear response over 10-4 to torr, all ion-gauge measurements are seriously affected by gas composition. For example, He gas only produces of the signal that N2 gas does,

۸ via venturi, mechanical, or sorption pumps
Modern Devices: The Simple Physics of Sophisticated TechnologyCopyright © John Wiley and Sons, Inc.mufflerFigure 4.7 In a venturi pump, a gas flows through a restriction, causing the pressure to drop. An opening (bottom) pulls air from the volume to be evacuated. Only low-quality, rough vacuums can be established with this device.Low vacuumvia venturi, mechanical, or sorption pumps

۹ via venturi, mechanical, or sorption pumps
Modern Devices: The Simple Physics of Sophisticated TechnologyCopyright © John Wiley and Sons, Inc.Right Sorption Pump without Styrofoam sleeveLeft Sorption PumpStyrofoam sleeve tohold liquid nitrogenValveVenturiPumpThermocouple& gaugeMetalHoseFigure 4.8 A pair of sorption pumps along with supporting equipment is shown. These pumps function by cooling the residual gas from the chamber to the point where it condenses to liquid form. The pictured pump station has valves so one or both sorption pumps can be used and gauges to measure two stages of vacuum.Low vacuumvia venturi, mechanical, or sorption pumpsPumps are classified into two types: gas transfer and gas capture. A sorption pump is a gas capture type. It pulls a vacuum by trapping and condensing most gases into the liquid phase. Eventually, gas capture pumps become full, must be taken off line, and heated to drive out the captured gas.

۱۰ via diffusion, turbomolecular, or cryogenic pumps
Modern Devices: The Simple Physics of Sophisticated TechnologyCopyright © John Wiley and Sons, Inc.Oil reservoirTo roughingPumpSeparateLN2 TrapVacuum ChamberExteriorflow ofcoolingwaterHeating elementFigure 4.9 A schematic representation of a molecular diffusion pump is shown. A heating element causes a special oil of large, complex molecules to boil, sending small amounts of oil upward as depicted by the gray arrows. The oil strikes deflectors and is gravitationally pulled back towards the oil reservoir, dragging residual gas molecules down to the lower portion of the pump. A roughing pump continuously removes the slightly over-pressurized gas caused by the oil flow.High Vacuum (HV)via diffusion, turbomolecular, or cryogenic pumpsIn contrast to the gas-capture sorption pump, the molecular diffusion pump is a gas transfer type. A foreline pump must first be used to achieve a vacuum at or below the crossover point. Then the chamber can be opened to the diffusion pump, but the foreline pump must be used a second time to remove the transferred exhaust from this main pump.

۱۱ via diffusion, turbomolecular, or cryogenic pumps
Modern Devices: The Simple Physics of Sophisticated TechnologyCopyright © John Wiley and Sons, Inc.Venturi  ۸K He15 K cold vanes to trap N2, O2CompressorPressurizedHe gas inputHe gas return80K cold head to trap H2OReflective, 80K ShieldFigure 4.10 A cryogenic pump operates by dramatically changing the pressure of He gas at two points in the cycle. The sudden drop in the He pressure causes it to go from approximately room temperature to about 10 degrees above absolute zero. The helium is connected to a series of vanes, which become sufficiently cold to freeze the residual gas from the vacuum chamber.High Vacuum (HV)via diffusion, turbomolecular, or cryogenic pumpsA Cryopump is an oil-free high-vacuum pump of the gas capture type. Cryopumps, properly known as cryogenic pumps, are similar to sorption (cryosorption) pumps, except portions of the pump are substantially colder. The basic physics behind the cryopump is to create an ultimate refrigerator and attach a cold finger to a series of progressively larger cold surfaces. The primary requisite is to get various surfaces sufficiently cold that various gas constituents are frozen or adsorbed onto one of several surfaces and held there for extended periods. It normally takes about 2 hours before a cryopump gets down to operating temperatures. These pumps require extensive roughing to vacuum pressures of ~50 microns (~5 x 10-2 torr) on the pump itself prior to turning on the compressor.

۱۲ Ultrahigh Vacuum (UHV)
Modern Devices: The Simple Physics of Sophisticated TechnologyCopyright © John Wiley and Sons, Inc.Figure 4.11 Ion pumps produce strong internal electrical fields, which accelerate the electrons and positively charged molecules. Many of these charges strike titanium or titanium and tantalum plates releasing a few Ti or Ta atoms, which chemically bond with gas molecules and then become adsorbed onto the interior walls of the pump in a process known as gettering. The sequence of events also produces more ions, which continue the pumping process.Ultrahigh Vacuum (UHV)via ion pumpsIon pumps are the best choice for UHV chambers, since these pull the hardest vacuums, as well as are clean, vibration free, and can be baked. Ion pumps also have low power consumption and long operating lifetimes despite being a gas capture type pump.

OIL-SEALED PUMPS AND BACKSTREAMING

vacuum leak detector

۱٫ How does the Prowler sensor work?

As refrigerant gas enters the sensor, a tiny chemical reaction occurs that results in an electrical change inside the sensor element. This change (which is completely reversible and not depleting) is then detected by a microprocessor (computer chip) that translates the chemical reaction into an alarm signal.

۲٫ How does the Prowler sensor compare to heated sensor leak detectors?

Besides having superior sensitivity, especially to the newer HFC refrigerants, the Prowler sensor also operates at a lower temperature than heated sensors. This is an advantage because it draws less current and doesn’t require the use of rechargeable batteries. Another advantage is that it can be used safely in combustible atmospheres.

۳٫ What happens when the Prowler detects that a leak is present?

When refrigerant gas enters the sensor, the Prowler detection circuit initiates three indicators that show a leak is present. The user hears an audio alarm (when not manually muted), feels a vibration in the handle, and sees the bar graph line(s) appearing on the LCD screen. Both the audio and vibration alarm are constant no matter how large the concentration of the gas. The LCD bar graph changes depending on the concentration of the gas in the sensor. The bar graph is also independent from the sensitivity level selected.

۴٫ How does the Prowler work so that the source of the leak can be located?

Unlike other leak detectors, the Prowler incorporates several innovative high technology features that allow the user to find the source of the leak without requiring any manual adjustments. Advanced computer software constantly monitors the surroundings for the presence of refrigerant gas. The detector then automatically calibrates itself so that it alarms only when it senses an increase in the level of refrigerant as the source of the leak is approached. The proprietary software then “filters” out and virtually eliminates any unwanted (false) alarm signals that occur away from the leak source.

 ۵٫ Will the Prowler detect large leaks without any manual adjustments?

Yes. However, if the Prowler alarms initially close to a large leak and then stops alarming before the source of the leak can be pin pointed, it means that the concentration of refrigerant in the area near the leak is similar to the concentration at the leak source. In this situation, it is important to move the sensor away from the leak source (usually above the suspected leak source) for 5 to 10 seconds to allow the sensor to self calibrate to a lower concentration before searching the area a second time. The detector will then alarm again closer to (or at) the source of the leak. Holding the probe away in this manner will also give a more accurate indication of the leak size on the bar graph.

۶٫ Will the Prowler alarm when entering a work area contaminated with refrigerant?

Yes. Nevertheless, you must always turn on the Prowler outside of the work area (in clean air) and allow it to complete the warm up cycle before entering an area where a large leak is suspected. The Prowler will alarm initially but will automatically self calibrate to the surroundings and will not alarm again until a larger concentration closer to the source of the leak is detected.

۷٫  Why does the alarm stop sounding when the sensor is held static at a leak source?

This is normal and demonstrates how the detector automatically resets (self calibrates) itself to the ambient. Once the Prowler alarms near the area of the leak, it should be moved away from the leak and back again to verify the exact location and size of the leak. If the leak is large (more than five bars), it may be necessary to move the sensor away from the leak area for 5 to 10 seconds.

۸٫  Can the Prowler determine the size of the leak?

Yes, once the leak has been pin pointed the maximum number of bars on the LCD screen will give the user an idea of the size of the leak. If the leak is large, (5 bars or more) it may be necessary to hold the detector away from the leak for 5 to 10 seconds in order for the circuit to reset completely and to give an accurate indication of the leak size.

 ۹٫  What does the Prowler do when it is turned on and is going through the warm up mode?

When turned on, the Prowler begins to energize and condition the sensor for use.  During this period, the unit will beep at a slow rate and the LCD bar graph will display the conditioning progress by gradually increasing.  Warm up is complete when all 10 bars are shown on the display. The beep rate will also increase and the sensitivity level will default to Medium.  NOTE: The bars on the bar graph may increase up initially and then down again before increasing to 10 full bars – this is normal.

۱۰٫ How should the Prowler be tested to make sure it is working properly prior to leak searching?

The preferred method to test the Prowler is with the Leak Test Vial that is included with the leak detector.  Although the Vial does not contain refrigerant gas or liquid (this is prohibited), the media in the Vial accurately simulates a small to medium refrigerant gas leak.  To test with the Vial, power on the Prowler by depressing the on/off button, allow the instrument time (up to 20 seconds) to energize the sensor, remove the plastic label seal on the top of the Leak Test Vial, and place the sensor closer to the small hole in the top of the Vile.  The beep rate should increase and the Leak Size Bar Graph should display a minimum of three bars.  The detector will calibrate itself to the Leak Test Vial if the sensor is held static close to the hole in the cap and will not alarm again until it is moved away and allowed to reset.  Consecutive testing at the cap and moving away from Vial will eventually result in the detector calibrating itself to the Vial.  In this case, the Prowler may require additional time away from the Vial in order to reset before it will alarm again at the Leak Vial.  Never use the Leak Test Vial with the cap removed from the bottle. NOTE: If the detector has been out of use for weeks, it may be necessary to set the sensitivity level to HI initially when testing the Prowler with the Leak Test Vial.

۱۱٫ Is there a way to test the Prowler with Refrigerant Gas before leak checking:

If it is necessary to test the Prowler with refrigerant gas, a small leak can be simulated by removing a Schrader valve cap on an access port of an HVAC system and waiting a few minutes for the accumulated gas to escape. Cracking open and quickly closing the valve on a cylinder of refrigerant is another option; however, the area around the valve should be fanned to allow the gas to dissipate before testing with the Prowler. This test method is not advisable because it is difficult to control the amount of gas emitted from a refrigerant cylinder. Opening and closing the valve on a cylinder typically emits a large volume of refrigerant, which is not representative of an actual leak in an HVAC system. If the Prowler is tested this way, the procedure for finding large leaks (see above) should be followed. If the procedure for finding large leaks is not followed, the automatic calibration feature of the Prowler may cause it to appear to be insensitive.

۱۲٫ Will the Prowler sensor become damaged if it is exposed to a heavy stream of gas coming from the valve of a refrigerant cylinder?

No. However, exposing the sensor to a heavy stream of refrigerant will cause the sensor to “saturate” and it may take up to 15 or more seconds for the sensor to automatically calibrate and reset to its maximum sensitivity level. For this reason, using a refrigerant cylinder is not an advisable means to test the sensitivity of the Prowler to any particular refrigerant.

۱۳٫ How can you claim the sensor will last up to 10 years?

The Prowler utilizes sensor technology that is based on room monitoring where sensors are required to be functioning continuously for years. Sensors used for this purpose cannot be depleted when contaminated with refrigerant or require any adjustment to operate at peak performance after running continuously for long periods. By converting continuous use into daily use, for a typical HVAC technician, it was determined using controlled test methods that the sensor would last more than 10 years (under ideal conditions). The sensor life test data was derived after testing the Prowler sensors continuously over a period of time.