Chapter 1

Troubleshooting of Malfunctioned PLC Controlled Rectification Pilot Plant

Chapter 2Technical Information

Chapter 2Technical Information

Our Pilot plant & Pipeline components manufactured from borosilicate glass 3.3 are widely used as the basis for the construction of complete process systems throughout the chemical & pharmaceutical industries, as well as many related areas such as food & drink production, dye works & electroplating industry. One reason for this widespread use is the special properties of borosilicate glass 3.3, complemented by the use of other highly corrosion resistant materials such as PTFE & ceramics. Secondly, borosilicate glass is an approved & proven material in the construction of pressure equipment.Chemical CompositionThe special properties especially its high chemical resistance, its resistance to temperature & its low co-efficient of linear expansion-of the borosilicate glass 3.3 exclusively used by QVF for the construction of glass plant & pipeline are achieved by strict & adherence to its chemical composition, which is as follows:Components% by weight

SiO280.6

B2O312.5

Na2O4.2

Al2O32.2

Trace Elements0.5

Table 1Properties of Borosilicate Glass 3.3The very wide use of this material throughout the world in the chemical & pharmaceutical industries as well as many other allied areas is mainly due to its chemical & thermal properties together with the great number of other benefits that distinguish borosilicate glass 3.3 from other materials of construction. These include special properties such as: Smooth, Non-porous Surface No Catalytic Effect No Adverse physiological properties Neutral Smell & taste Non-flammability TransparencyChemical ResistanceBorosilicate Glass 3.3 is resistant to chemical attack by almost all products, which makes its resistance much more comprehensive than that of other well-known materials. It is highly resistant to water, saline solutions, organic substances, halogens such as chlorine & bromine & many other acids. There are only a few chemicals which can cause noticeable corrosion of the glass surface namely hydrofluoric acid, concentrated phosphoric acid & strong caustic solutions at elevated temperatures.However at ambient temperature, caustic solutions up to 30% concentration can be handled by borosilicate glass without difficulty.The attack on the glass surface can initially increases as the concentration of the caustic solution increases but after exceeding a maximum it assumes a virtually constant value. Rising temperatures increases the corrosion, while at low temperatures the reaction speed is so low that reduction of the wall thickness is hardly detectable over a number of years.Diagram input: Fig 2Physical propertiesThe borosilicate glass 3.3 differs from other material of construction used for process plant not only because of its virtually universal resistance to corrosion but also because of its very low thermal low expansion coefficient. There is, therefore no need for expensive measures to compensate for thermal expansion resulting from changes in temperatures. This becomes of particular significance the layout of long runs of glass pipeline. Mean linear thermal expansion coefficient 20/300 = (3.30.1)x E-6 K-1

Mean thermal conductivity b/w 20 & 200oC20/200 = 1.2 W m-1 K-1

Mean specific heat capacity b/w 20 & 100oCCp20/100 = 0.8 kJ kg-1 K-1

Mean specific heat Capacity b/w 20 & 200oCCp 20/200 = 0.9 Cp 20/100

Density at 20oC = 2.23 kg dm-3

Optical propertiesBorosilicate Glass 3.3 shows no appreciable light absorption in the visible area of the spectrum, in consequently it is clear & colorless. With Borosilicate glass 3.3, the transmission of UV light, which is of great importance for photochemical reactions, is somewhat greater in the middle spectrum than with normal window glass. The chlorine molecules absorbs in the 280 400nm range, & thus from the levels of the transmission shown in below figure, it can be seen that plant made from this material is, therefore, ideal for chlorination and sulphochlorination processes.If photosensitive substances are being processed, it is recommended that brown coated borosilicate glass 3.3 can be used. This special coating reduces the UV light transmission to a minimum, since the absorption limit as can also be seen from the figure below, it is changed to approximately 500 nm.Sectrans coated glass components, which have absorption limit of approximately 380 nm, are also ideal for the repetition.Figure 3Mechanical PropertiesThe permissible tensile strength of borosilicate glass 3.3 includes a safety factor which takes into account practical experience on the behavior of glass &, in particular, the fact that it is a non-ductile material. Unlike other materials of construction used for similar purposes. It is not able to equalize stresses occurring at local irregularities or flaws, as happens in the case of the ductile materials such as metals. The safety factor also takes into account additional processing which components may have undergone ground sealing surfaces, handling of the glass & permissible pressures & temperatures to which it may be subjected in use.The design figures indicated in the table below therefore apply to the permissible tensile, bending & compressive stress to which glass components maybe subjected taking into account the likely surface conditions of the glass in service.Strength ParametersTensile & bending strengthK/S = 7 N mm-2

Compressive strengthK/S = 100 N mm-2

Modulus of elasticityE= 64 kN mm-2

Poissons Ratio =0.2

Permissible Operating ConditionsThe permissible values for operating temperature & pressure must always be seen in combination. The reason for this is the thermal stresses that result from temperature difference between the inner & outer surfaces of glass component. These stresses are super imposed on the stresses resulting from the working pressure. High thermal stresses result in a reduction of the permissible working pressure. Thermal insulation reduces the thermal stresses & can, therefore, become a requirement of an installation.Permissible Operating TemperatureTransformation temperature for borosilicate glass is 525oC, therefore the permissible operating temperature is lower normally around 200oC, provided that there is no sudden temperature shock. At subzero temperatures tensile strength tends to increase that are why borosilicate glass 3.3 can be used safely at temperatures as low as -80oC.Permissible Operating PressureGlass components all nominal sizes that are basically cylindrical, domed & spherical can be used with full vacuum (-1 bar g), provided they are not specially marked otherwise. Thermal ShockIt is not possible to give a definite figure applicable to although operating conditions likely to be encountered in practice; a maximum permissible thermal shock of 120 K can be taken as a general guide.General Operating DataOperating temperature TB = 2000CTemperature Difference T 180 KHeat Transfer Coefficient Inside 1 = 1200 Wm-2 K-1, outside a = 11.6 Wm-2 K-1All components are suitable for full vacuum ps = -1 bar g

Risk Analyses/Residual RisksFollowing points should be observed:1. Although, borosilicate glass 3.3 is a material resistant to virtually all chemical attack, alkaline solutions, hydrofluoric acid & concentrated phosphoric acid can cause some erosion. If there is any concern that there may be a reduction in wall thickness, the required minimum wall thickness should be checked at regular intervals.2. Unstable fluids, substances that can decompose, call for special safety precautions in the use of glass plant.3. The permissible operating conditions should be observed & compliance insured if necessary by means of additional measures such as pressure relief valves, bursting disks, over fill prevention or temperature limiters.4. Extra loads, such as reaction forces on side branches, are not permissible. Bellows should be included in interconnecting pipe work to ensure a stress free connection to the glass plant.Mechanical Damage/Protective Measures:1. The tabular structure supporting the equipment or plant also provides protection against damage from external sources & prevents other items coming into contact with it.2. Parts of the Plant which are located outside the structure must be protected against mechanical damage.3. Parts of the plant, which can reach a surface temperature higher than 60oC in operation & which are located outside the support structure, must be provided with protection against contact.4. Additional safety devices are available in the form of safety screens, spray guards, coated & wrapped glass components.

Damage to Heat Exchangers:1. Should damage occur to the coil batteries in coil type heat exchangers or the heat exchange tubes in shell & tube heat exchangers, the service fluids & product can become mixed.2. Media which could react resulting in the generation of pressure & temperature (exothermic processes), should therefore be kept separate.

Specification Sheet of Column and Its associated Auxiliaries

The Boro Silicate Rectification Pilot Plant incorporates with many propriety and non-propriety mechanical electrical & process system that are integrated together for Safe & efficient processing monitoring and precision.The Plant auxiliaries have specification limits and operating parameters that has to consider prior to startup and operation. Borosilicate Plant is a prototype of Industrial commercialized plant thst employed contemporary process safety features for better understanding of the industrial operation it includes Inherent safety Control System,Interlocking, Emergency response system safety shutdown system and alarms.The Plant auxiliaries are incorporated linked to each other for efficient computerized controlling and monitoring.Following are the list of Plant & its associated devices that make up the whole plant. Gear Pump Vacuum Pump Vacuum system Electrically Hose heater or Pre Heater Flow Control System Pressure Relief Valve System Back Pressure Valve Differential Pressure Transducer Immersion Heator /Reboiler Level limit switch

DN 80Distillation ColumnDistillation towers are the heart of a process plant, and the working component of a distillation column is the tray. A tray consists of the following components: Overflow, or outlet weir Down comer Tray deckOur Distillation column contains two cartridges consists of five Bubble cap trays in each. Design specification is listed in the table below:

Tray EfficiencyOur Distillation trays in a fractionator operate between 10 and 90 percent efficiency. It is the process persons job to make them operate as close to 90 percent efficiency as possible. Calculating tray efficiency is sometimes simple. Compare the vapor temperature leaving a tray to the liquid temperature leaving the trays. For example, the efficiency of the tray shown in Fig. A is 100 percent. The efficiency of the tray in Fig. B is 0 percent.

Efficiency Calculation of 10 Tray Columns:

The average efficiency of ten tray column will be 10%. As the vapor temperature rising from the top tray equals the liquid temperature draining from the bottom tray, the 10 trays are behaving as a single perfect tray with 100 percent efficiency. But as there are 10 trays, each tray, on average, acts like one-tenth of a perfect tray. Poor tray efficiency is caused by one of two factors: Flooding Dumping/WeepingFloodingIt is brought about by excessive vapor flow causing liquid to be entrained in the vapor up the column. Depending on the degree of flooding the max capacity of the column severely reduced. Effects:1. Liquid entrainment in vapor1. Backing up of liquid in the down comer1. Sharp increases in column differential pressure1. Significant decrease in separation efficiency

Dumping/WeepingWeep point, the gas flowrate at which the first leakage of liquid starts because the gas flowing up through perforation is no longer able to counter balance the hydrostatic head of liquid on a tray.Effects:1. Temperature drop1. Pressure Drop1. Increase in reboiler duty

Distillation Column TurndownThe problem we have been discussingloss of tray efficiency due to low vapor velocityis commonly called turndown. It is the opposite of flooding, which is indicated by loss of tray efficiency at high vapor velocity.To discriminate between flooding and weeping trays, we measure the tower pressure drop. If the pressure drop per tray, expressed in inches of liquid, is more than three times the weir height, then the poor fractionation is due to flooding. If the pressure drop per tray is less than the height of the weir, then poor fractionation is due to weeping or dumping.Bubble Cap TrayOur distillation column is equipped with ten Bubble Cap Trays. Bubble-cap trays may be operated over a far wider range of vapor flows, without loss of tray efficiency. It is the proved that bubble-cap trays fractionate better in commercial service than do perforated (valve or sieve) trays. It is quite likely that the archaic, massively thick, bolted-up, cast-iron bubble-cap or tunnel-cap tray was the best tray ever built. However, compared to a modern valve tray, bubble-cap trays:1. Were difficult to install, because of their weight.1. Have about 15 percent less capacity because when vapor escapes from the slots on the bubble cap, it is moving in a horizontal direction. The vapor flow must turn 90. This change of direction promotes entrainment and, hence, flooding.1. Are more expensive to purchase1. Will be used where low vapor rates to be handled.

The gas flows up through the riser, reverses flow under the cap, passes downward through the annulus between riser and cap, and finally passes into the liquid through a series of openings or "slots" in the lower side of the cap.Disadvantages:1. High Entrainment1. High Fouling Tendency1. High Capital Investment1. Large Pressure DropParts/Functioning of Trays1. Active Area (or Bubble Area)It is the deck area of the tray which may either be perforated or fitted with valves or bubble caps and is the area available for vapour/liquid contacting. The vapor handling capacity of a tray is proportional to the active area (i.e. inversely proportional to the approach to Jet Flood).

1. Down comer AreaIt is the area available for the transport of liquid from one tray to the next tray below. Also a very important function of the downcomers is to allow for the disengagement of vapour from the liquid which is a function of both residence time of the liquid in the downcomer. Undersized downcomers will result in downcomer flood.

1. Open Area (or Hole Area)is the aggregate area available for vapour passage through the tray deck via perforations or valve and bubble cap slots.This is a critical factor in the tray operating range since high vapour velocity through the open area (hole velocity) will induce heavy liquid entrainment (as well as high pressure drop), but low hole velocity may allow liquid to "weep" or even "dump" through the tray deck to the tray below. The influence of open a reaon pressure drop also impacts on the liquid back up in the downcomer.

1. Tray SpacingThis is the vertical distance between adjacent tray decks.This effects both the height of spray that may be generated on the tray deck before liquid carryover and also the allowable head of liquid in the downcomers.

1. Downcomer ClearanceThis is the space below the downcomer apron allowing liquid to flow from the downcomer to the tray deck below. This must be sized to provide a balance between the minimum head loss required for good liquid distribution across the tray deck and avoiding excessive downcomer backup.

1. Outlet Weir HeightThe outlet weir is used to maintain a head of liquid on the tray deck as well as to ensure a positive vapor seal to the bottom of the downcomer.

1. Flow Path LengthIt is the span of tray deck between the downcomer inlet and the outlet weir and is the shortest path that the liquid takes in crossing the active area from one downcomer to the next.This has a big influence on tray efficiency, particularly in small columns as well as trays with large or multiple downcomers.

Tower PressureAs observed through experiments, liquid on the tray deck was at its bubble, or boiling, point. A sudden decrease in the tower pressure caused the liquid to boil violently. The resulting surge in vapor flow promoted jet entrainment, or flooding. Alternately, the vapor flowing between trays was at its dew point. A sudden increase in tower pressure caused a rapid condensation of this vapor and a loss in vapor velocity through the tray deck holes. The resulting loss in vapor flow caused the tray decks to dump.Selecting an Optimum Tower Pressure1. Determines the maximum cooling water or ambient air temperature that is typically expected on a hot summer day in the locale where the plant is to be built. 1. Calculates the condenser outlet, or reflux drum temperature, that would result from the above water or air temperature.1. Calculates the pressure in the reflux drum, assuming that the condensed liquid is at its bubble point. Adding 5 or 10 psig to this pressure, for pressure loss in the overhead condenser and associated piping, the designer then determines the tower-top pressure.

2. Feed Preheater:Over View:A 600W electrical heated hose DN16 with temperature control having length 2.5m

Feed Preheater consist of a electrically hoses pipes one above the other through with feed is flow and are electrically heated to the required temperature as defined by the user through visualization panel or control system.Industrially the steam is used as a preheating medium but due to pressure implication associated with it the steam are not utilized in pilot plant as it has very low design pressure ranges.General Information:A heated pipe consists of a smooth surfaced PTFE inner tube, with one or more braided stainless steel cases. The electrical heating system is made up of heat conductor alloys and heating elements manufactured in accordance with the regulation. The thermal insulation will be adapted to suit your requirement.Operating Ranges: Temperature Ranges = 200 0C Pressure ranges = 8mbar to 44 barTemp & pressure above the stated maximum can result in the destruction of the hose.

Safety precaution: Please make sure that the fitting is not in a draught or under tension. The heated hose must have reached its operating temperature before you commencing working youre your normal pressures the material on the fitting may otherwise remain rigid. Do not try to reduce the warming up time with the help of external heat.

Technical Data for Standard Hose Line:

3.Rebolier:Circular evaporator equipped with one 3 KW electrical heater made of stainless steel

Overview:It consists of an Tubular electrical cartridge having 8.55mm diameter with an electrical source power of 1000W The Heater are known as immersion heater as it is dipped in the fluid. The coil through resistance produces heat and are transferred to the dipped medium. The Heater type is used for the heating of fluids in zone 1 and zone 2 environments.

Process Data:

Medium : Ethanol water mixture Max Temp TS:150 oC Max pressure PS:0.5 bar g Inlet Temp : 20oC Outlet temp:150oCSafety Precaution:

The surface temperature of the heated system may not exceed the limit temperature of the assigned temperature class with in the highly combustible range Control devices must be functionally checked with use as safety devices for the explosion prevention according to the relevant regulations During operation the environment temperature must not fall below -20oC and the environment temperature of +40 must not be exceeded. Do not operate the coil dry.

4. Dozing/Metering Gear Pump:

A 240ml/min capacity gearOverview:Gear pump are rotary displacement pump in which two gears engage with each other. The transfer of fluid is caused by counter rotation of two gears in a gear chamber. The gear is fixed on two shafts, which are running in bearing in the causing and the cover. The shaft drives one gear together is driven by the first gear. The opening teeth create a suction which pulls the liquid into the pump. The liquid is transported between the teeth and the gear chamber to the pressure side. When the gear teeth meet again the liquid is squeezed out and pressed in to the outlet port.in this way liquid can be pumped against pressure.

Relief valve:The relief valve protect your system against high pressure.it is adjustable to crack between 0 and 7 bar, when cracking the valve relieves internally from pressure to suction side to protect the system and pump from damage. Safety Precaution: Be sure the pump head is cleaned with a nontoxic liquid.in the event the pump head was operating with dangerous or noxious liquid use necessary safety precaution. If necessary disinfect the piping and the pump head.Avoid dry running at startup longer than 30 seconds

WARNING:If you intend to operate the pump outside of the above given parameters please ask the manufacturer of the pump. Modification in this regard may be necessary to ensure successful operation, otherwise the pump or our system may be damaged.

5. Back Pressure Valve:

Overview:Series DHV-S-DL back pressure valves serve the purpose of creating constant backpressure to ensure exact media feed rates and to protect against overloading while also increasing the metering accuracy when metering against atmospheric pressure.Used as overflow valves in by pass systems, they protect pump, lines and fitting from overpressure as the result of incorrect operation or blockages.

Operating Ranges:The pressure and temperature of the metered medium must be below the corresponding curves otherwise the back pressure valves may fail prematurely.

Trouble shooting:

Technical Data:

The Back pressure valve can be used together with the metering pumps alpha, beta, gamma/L, G4, G5, Extronic&Pneumados.Used as Backpressure valve for generating a constant backpressure, and an over flow valve to protect the system also used in conjunction with pulsation damper to facilitate low-pulsating metering.

12Troubleshooting of Malfunctioned Rectification Pilot Plant