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Wednesday, September 26, 2007

MICROCONTROLLER BASED WATER PURIFIER

MICROCONTROLLER BASED WATER PURIFIER

ABSTRACT

Water is one of the nature’s most simple substances. Human body Consists of 65% of water. One may live without food for more than a Month, but it is impossible water for more than a day. On average we consume 2.5 liters of water a day. Unfortunately, the water we consume can be polluted. Polluted water may look clean and even taste okay, but may contain germs and other impurities that cause water borne diseases. This is why it is extremely important to ensure that these impurities are removed before such water can be used safely for consumption. Water provides an ideal environment for growth of microbial contamination the abundant supply of nutrients available in the water help Bacteria and Viruses, to grow, live, reproduce and die. The microbial contamination causes diseases like Gastric-enteritis, Diarrhea, Dysentery, Jaundice, Cholera, Polio, in fact over 80% of all human diseases is water borne. For many years various techniques have been used to provide microbial control in water for industrial and domestic use.



CHAPTER 1
INTRODUCTION

1.1 IMPORTANCE OF SAFE DRINKING WATER
Water one of nature’s most simple substances. The human body consists of 65% of water. One may live without food for more than a month, but it is impossible to survive without water for more than a day. On average we consume 2.5 liters of water a day. Unfortunately, the water we consume can be polluted. Polluted water may look clean and even taste okay, but many contain germs and other impurities that cause water borne disease.
This is why it is extremely important to ensure that these impurities are removed before such water can be used safely for consumption. Water provides an ideal environment for growth of microbial contamination. The abundant supply of nutrients available in the water help bacteria and viruses, to grow live reproduce and die.
The microbial contamination causes diseases like Gastro-enteritis, Diarrhea, Dysentery, Jaundice, Cholera, and Polio, in fact over 80% of all human diseases are water borne. Water provides an ideal environment for growth of microbial contamination. The abundant supply of nutrients available in the water help bacteria and viruses, to grow live reproduce and die.
For many years various techniques have been used to provide microbial control in water for industrial and domestic use. The technique and their disadvantages as follows.



1.2 METHODS OF PURIFICATION & DISADVANTAGES OF IT

1.2.1 Boiling
It is effective against cysts bacteria and spores only if the water is boiled at 1200C for 20 minutes in wet heat (steam) at atmospheric pressure. Recontamination can take place after 8 hours of cooling. Since water never brought to a rolling boil, most harmful pathogens get away unscathed. Hence even tea cannot be considered safe to drink and boiling is also an expensive and time-consuming process.

1.2.2 Filtration
Filters remove visible dirt particles. They merely trap Bacteria, but do not destroy them in fact sometimes if not cleaned regularly the filter may serve as a breeding ground for bacteria. And Viruses are too minute to be trapped by these candle filters.

1.2.3 Chemical Treatment

1.2.3.1 Chlorine
Though chlorine continues to be the most commonly used sterilizing agent because of its germicidal properties and low cost, it is being viewed with suspicion due to the discovery that excessively chlorinated water can lead to formation of many homogenate compounds like trihalmethane (THMS) and chlorophenols which are carcinogenic in nature. If the chlorine concentration falls below the required concentration, it will defeat the purpose for which it was employed. *Carcinogenic cancer causing.

1.2.3.2 Iodine
Iodine is a suspect chemical, as one does not know its effect on human body over long periods of time. Iodine in excess is considered toxic. It is harmful it is given to people with thyroid hyperactivity.

1.2.3.3 Alum
It is not germicidal in nature and only has ability to help settle suspended physicals particles. It also has the ability to irritate the throat.

1.2.3.4 Potassium permanganate
It is poisonous if taken in excess and should not be used for domestic use. It colors the water to a pinkish tinge.

1.2.4 Tap Attachments

1.2.4.1 Filters
They can be of two types, the tap attachments or the ceramic filter types. Both of these have a pore size of 10-15 microns. The sizes of certain virus and bacteria are between 0.01 to 1 microns and hence though filters can remove only physical particles, they are totally ineffective against microorganisms. These types of filters actually acts as excellent breeding grounds for microbial growth as they are most ventilated surfaces where physical particles are trapped and begin to delay.

1.2.4.2 Ultra Violet Radiation
Ultra Violet rays are an effective technique but it just inactivates Bacteria and Viruses. Hence poses potential hazards. The other drawbacks of the systems are
Ø A certain volume of water requires a minimum exposure time to the UV radiation.
Ø Dosage of the UV radiation also dependent on the flow rate and the total exposure time.
Ø Storing of water not recommended – U/V rays would not kill spores. This is the reason why generally the manufactures recommend that water should be consumed as soon as it comes out of the unit. So water purified by this method cannot be stored at all.
Ø Direct Exposure of UV may cause health hazards.
Ø The Ultra Violet tube has a definite life and has to be replaced.
Ø U/V has no effect recorded on Viruses.
Ø The unit is installed in such a way that there is a polypro prefilter and there is also an activated carbon filter fixed before the water enters the unit. The unit cannot operate without a prefilter, as there is a turbidity control, which ensures that the unit does not work even the water is slightly turbid.
Ø Another fact to be considered is that the UV rays inactivate bacteria by working on their DNA and slops the reproductive process of the Bacteria. Bacteria has a total life of 20 minutes and after it gets it gets hit by UV rays it passes through dark area the bacteria can be reactivated but cannot reproduce. This process only inactivates bacteria but cannot destroy it.
Ø The unit does not effectively work with hard water. There is that a protective glass jacket is used around the UV tube and another glass tube is fitted around the jacket. Water flows in between these glass in between these two tubes then a white coating forms on the outside of the glass jacket there by preventing penetration of UV rays into water to be purified. This reduces the effectiveness of the unit and some times unit does disinfect at all. To make the unit effective at all times the glass jacket has to be cleaned regularly which makes the method maintenance prone. Also when the tube has top be cleaned cannot be ascertained as it depends on the quality of water.

1.2.5 Oxidization
Oxidation is the combination of a substance with oxygen. Oxidation means a substance undergoes a chemical change resulting in a different Substance. Odors and pollutants are broken down into harmless, odorless compounds such as carbon dioxide, water vapour and oxygen.

1.3 OZONIZED PURIFICATION VS OTHERS

1.3.1 Ozonized Purification Vs UV-Purification
Maintenance cost of UV based purifiers is normally high; Since the UV lamp frequently needs to be replaced and requires regular cleaning of Quartz glass used in UV chamber. The disinfections of viruses & Spores are Excellent in Ozone based water purifiers but which is poor in UV based purifiers.

1.3.2. Ozoniztion Vs Biocides
Ozone is not irritating to humans, in quantities required to purify water. It leaves no by products expect pure oxygen. The oxidation power of Ozone is three times more than chlorine. Chlorine at normal level does not destroy cysts of amoeba where as Ozone destroys it.
Table 1.1 shows the comparison methods of various water purification methods. From this it will be clear that the ozonization method of water purification is the better one, since most of the comparison description shows that the ozonization method water purification is the better approach. It also is clear that it is also economically efficient since the cost for the purification of water is low when compared to the other methods of purification of water.







1.4 DETAILS OF OZONE

1.4.1 Definition
Ozone is a tri atomic allotrope of oxygen formed by the recombination of oxygen atoms. The un reacted Ozone also decomposes to form oxygen making it environment friendly, often called the environment friendly or the green chemical of the future. Ozone is allotropic oxygen. Ecologically the most acceptable disinfections agent for water. Ozone effectively destroys Bacteria, Virus and water borne parasites. And is also capable of destroying bad odor and color in water, which other organic compounds create.
Ozone is second only to fluorine as a powerful oxidant and it is a most powerful water disinfectant. Ozone destroys Bacteria and virus much faster than chlorine by rupturing cell walls and oxidizing the nucleic acids like DNA and RNA. Ozone destroys bacteria in seconds while chlorine and other biocides take 30 minutes to several hours for the same result. Ozone also functions as clarifying agent to polish the water and improve quality. The Ozonized water will be free from the microorganisms and rich in oxygen.

1.4.2 Formation
In the stratosphere, OZONE is formed by the sun’s ultraviolet light. Exciting oxygen molecules to a higher energy level to produce unstable oxygen atoms can also produce OZONE. A small percentage of these single atoms combine with other oxygen molecules to form ozone,
O+O2 = O3. Ozone thus formed is very unstable with a half; if of about 20 minutes in water and 10 hours in air before the unreacted molecules decompose to oxygen. Due to this unstable nature, Ozone must be generated on site.

1.4.3 Properties
Ozone is pH neutral. It has no effect on the taste of water.
Ø The system uses tiny amounts to be effective. Ozone is very gentle to humans and equipment.
Ø Ozone will not explode.
Ø Ozone is not a fire hazard.
Ø In the dose required for excellent purification, Ozone does not produce harmful fumes.
Ø Ozone will not damage plumbing fittings or pipes.

1.4.4 Applications Of Ozone
Ø Potable Water
Ø Bottled Water
Ø Cooling tower Water Treatment
Ø Swimming pools and spas
Ø Ultra Pure water
Ø Industrial process water
Ø Odor removal
Ø Effluent treatment
Ø Fish Farming
Ø Ozone Therapy
Ø Air purification


1.4.5 Effects
Ø The Ozone layer in the atmosphere protects the earth from deadly radiation
Ø Ozone destroys bacteria, Viruses mold and mildew.
Ø Ozone eliminates spores, cysts, yeast, fungus and smoke.
Ø Ozone oxidizes iron, sulfur, manganese and hydrogen sulfate.
Ø Ozone eliminates oils, odors and other contaminants in water.
Ø Ozone keeps water, fresh and sparkling.

1.4.6 Biological action in water
Ozone destroys Bacteria & Virus by rupturing cell walls and oxidizing the nucleic acids like DNA and RNA. Ozone destroys Bacteria in seconds while chlorine and other biocides take 30 minutes to several hours for the same result Ozone diffuses cell walls, and then oxidizes the bacteria’s enzymes.
Ozone molecule is a very powerful oxidizer and sanitizer. It destroys anything it comes in contact with, faster and more effectively than anything else available, and when the sanitation is complete, or if Ozone finds nothing to oxidize, it returns to molecular oxygen (2 atoms).

1.4.7 Benefits
Ø Ozone is generated “onsite” and is introduced into the water or air automatically
Ø Ozone does not have to be purchased or stored.
Ø Ozone does not affect the pH balance of water, thus minimizing pH adjustments.
Ø Ozone helps reduce total dissolved solids in water so that the water does not have to be changed as often.
Ø Ozone eliminates much of the routine maintenance because it does such an effective job keeping the water or air clean.


1.4.8 Effect on environment
Ø Ozone leaves no chemical by-products in water.
Ø Ozone leaves no chemical taste or smell.
Ø Ozone will not burn eyes or make them red or irritated.
Ø Ozone will not discolor or damage hair or clothing.
Ø Ozone adds no contaminants or by-products to water.
Ø Ozone rids water and air of unhealthy microorganisms.
Ø Ozone is NOT a carcinogen.


CHAPTER 2
OZONIZATION PROCESS

2..1 GENERAL
In this chapter, the explanation about the ozonization process is described in a short manner. The schematic representation of the process is given in the following section at the fig (2.) 1). before that the component description is given in the following section.

2.2 COMPONENTS DESCRIPTION

2.2.1 Air Drier Bottle
Air Drier Bottle adds longevity to the Ozone G-generator by absorbing moisture From atmospheric air. The bottle is filled with Silica Gel and the color of the material is Dark Blue, which will fade when it absorbs moisture from atmospheric air. So Silica Gel needs to be regenerated after the life time (Programmed by Micro Controller)

2.2.2 Ozone Generator
Here Ozone is produced by expressing oxygen to high voltage discharge. When air (O2) flows through Ozone generator, which contains two electrodes separated, by a thin gap at low current and high voltage electric discharge say 4KV, oxygen is ionized with characteristic bluish glow like lightning. This kind of Ozone discharge generator is called corona discharge generator. As the air drawn through the chamber by four equally shared electrons, the molecular excitation of oxygen molecules into oxygen atoms takes place. Some of these atoms then equally react with oxygen molecules to form Ozone. The Ozone thus produced is very unstable and converts itself into more stable oxygen.


















Fig2.1 Structure of ozone generator

2.2.3 Pump Assembly
Pump assembly is used to shuffle the water stored in the tank with Ozone. And also used to discharge the water from the tank after the disinfections process. For this a 12V Dc Motor is used and covered with an ABS material.



2.2.4 Injector
Here the Ozone from the Ozone generator is injected through a thin capillary tube into water disinfections process. (Water recycled from tank).

2.2.5 Solenoid Valve
Two-way valve is a mechanical device in which one way is used to recycle the water from tank during disinfections process and the other way is used to draw water from the storage tank after disinfections process.
When a Nylon plunger is pressed one way is closed and other way opens, when plunger is released one way opens and the other way closes.











Fig 2.1. Schematic representation of the process



2.3 PROCESS EXPLANATION
The air which comes into the air drier gets dried up and the dried air goes out of the air drier bottle and get into the ozone generator, As the air drawn through the chamber by four equally shared electrons, the molecular excitation of oxygen molecules into oxygen atoms takes place. Some of these atoms then equally react with oxygen molecules to form Ozone.
The Ozone thus produced is very unstable and converts itself into more stable oxygen. Is injected into the injector. In the mean time, the water from the underground is pulled up by the pump, which is used to shuffle the water stored in the tank with Ozone.
And also used to discharge the water from the tank after the disinfections process. And that water is passed across the two way valve, which one way is used to recycle the water from tank during disinfecting process and the other way is used to draw water from the storage tank after disinfections process and it is opened in such a direction, which supports for a closed loop purification.
The water from the two-way valve is pushed forward into the injector and thus ozone gas gets mixed with the water and thus the cell walls of all the microbes get detached.
This process is continued for 3 minutes and after that the solenoid valve is opened at the other side and so the purified water comes out of the other side and ready for drinking purpose.
After rupturing the cell walls of all the microbes, the ozone gas gets converted to oxygen by anionic action. Ands, it is safe for drinking and bathing purpose.


2.3.1 Process Automization
To make this process automatic one, microcontroller is established which controls the three-solenoid valves and the 12V DC motor, which has been explained in the following chapters.










CHAPTER 3 MICROCONTROLLER

3.1 THE 89C51 ARCHITECTURE
The 89C51 consists of:
Ø Eight-bit CPU with registers A (the accumulator) and B
Ø Program Counter (PC)
Ø Data Pointer (DPTR)
Ø Flags and the Program Status Word (PSW)
Ø Eight-bit stack pointer (SP)
Ø Flash Rom
Ø RAM of 256bytes (128bytes general purpose)
Ø Four register banks, each containing eight registers
Ø Thirty-two input / output pins arranged as four 8-bit ports
Ø P0-P3
Ø Two 16-bit timer /counter: T0 and T1
Ø Full duplex serial data receiver / transmitter; SBUF
Ø Interrupts
Ø Oscillator and clock circuits

3.1.1 CPU Registers
The 89C51 contain 34 general-purpose, in working, registers. Two of these, registers A and B hold results of many instructions, particularly for arithmetical and logical operations. The other 32 are arranged as part of internal RAM in four banks, Bank0-Bank3, of eight registers each. The A and B registers are also called as CPU registers.


3.1.2 The “A” (Accumulator) Register
The A (accumulator) register is the most versatile of the two CPU registers and is used for many applications, including addition, subtraction, integer multiplications. It can hold an 8-bit (1-byte) value and is the most versatile register in the 89C51. The register is also used for all data transfers between the 89C51 and any external memory. More than half of the 89C51’s instructions manipulate or use the accumulator in some way.

3.1.3 The “B” Register
The B register is used with the A register for multiplication and division operations and has no other function other than as a location where data may be stored. The “B” register is only used by two 89C51 instructions: MUL AB and DIV AB Aside from the MUL and DIV instructions, the “B” register is often used as yet another temporary storage register much like a ninth “R” register. The “B” register is very similar to the Accumulator in the sense that it may hold an 8-bit (byte) value. Thus, if you want to quickly and easily multiply or divide “A” by another number in “B” and make use of these two instructions.
While doing multiplication the higher order byte of the result is stored in “B” register and lower order of the result is stored in accumulator and for division the quotient is stored in accumulator and the remainder is stored in “B” register.
Other than Multiplication and division functions, user can directly move the data from accumulator and direct data to “B” register. The instructions are MOV B, A
MOV B, #XXH (XX is nothing but hex data)
MOV A, B

3.1.4 Program Counter
The 89C51 contain two 16 bit registers: the program counters (PC) and the data pointer (DPTR). Each is used to hold the address of a word in memory.
Program instruction bytes are fetched from locations in memory that are addressed by the PC. Program ROM may be on the chip at addresses 000h to Fifth, external for address that exceed FFFh, or totally external for all address from 0000h to FFFFh. The PC is automatically incremented after every instruction byte is fetched and may also be altered by certain instructions. The PC is the only register that does not have an internal address.
The program counter (PC) is a 2-byte address that tells the 8951 where the next instruction to execute is found in memory. When the 8951 are initialized PC always starts at 0000h and is incremented each time an instruction is executed. It is important to note that PC isn’t always incremented by one since some.
Instructions require 2 or 3 bytes the PC will be incremented by 2 or 3 in these cases. There is no way to modify it value. The program counter is special in that. That is to say, you cannot do something like PC=2430h. On the other hand, if you execute LJMP 2340h you’ve effectively accomplished the same thing.
It is also interesting to note that while you may change the value of PC (by executing a jump instruction, etc.) there is no way to read the value of PC. That is to say, there is no way to ask the 8951 “What address are you about to execute?”

3.1.5 Data Pointer (Dptr)
The DPTR register is made up of two 8 bit registers, named DPH and DPL, which are used to furnish memory addresses for internal and external code access and external data access. The DPTR is under the control of program instructions name; DPH and DPL are each assigned an address. The data pointer is the 89C51’s only user accessible 16 bit (2 byte) register. DPTR, as the name suggests, is used to point to address something like HL register pair in 8085 microprocessor. It is used by a number of commands that allow the 8951 to access external memory and internal memory.
While DPTR is most often used to point to data in external memory, many programmers often take advantages of the fact that it’s the only true 16-bit register available. It is often used to store 2 byte values that have nothing to do with memory locations.

3.1.6 Program Status Word (PSW)
Flags are 1 bit registers provided to store the results of certain program instructions. Other instructions can test the condition of the flags and make decisions based on the flag states. In order that the flags may be conveniently addressed, they are grouped inside the program status word (PSW) and the power control (PCON) registers.
The 8951 have four math flags that respond automatically to the outcomes of math operations and three general-purpose user flags that can be set or cleared to 0 by the programmer as desired. The math flags include Carry (CY), Auxiliary Carry (AC), Overflow (OV), and Parity (P). User flag is named F0; this general purpose flags that may be used by the programmer to record some event in the program. Register bank selection may be done by the use of RS0 and RS1. Note that all of the flags can be set and cleared by the programmer at will. The math flags, however, are also affected by math operations.
The PSW contains the math flags, user program flag F0, and the register select bits RS0, RS1 that identify which of the four general purpose register banks is currently in use by the program.

3.1.7 The Stack And The Stack Pointer
The stack refers to an area of internal RAM that is used in conjunction with certain opcodes to store and retrieve data quickly. The 8-bit Stack Pointer (SP) register is used by the 8951 to hold an internal RAM addresses that is called the top of the stack. The address held in the SP register is the location in internal RAM where the last byte of data was stored by a stack operation.
When data is to be placed on the stack, the SP increments before storing data on the stack so that the stack grows up as data is stored. As data is retrieved from the stack, the byte is read from the stack, and then the SP decrements to point the next available byte of stored data.
The stack is limited in height to the size of the internal RAM. The stack has the potential (if the programmer is not careful to limit is growth) to over write valuable data in the register banks, bit addressable RAM, and general purpose (scratchpad) RAM areas. The programmer is responsible for making sure the stack does not grow beyond predefined bounds.
The stack is normally placed high in internal RAM, by an appropriate choice of the number placed in the SP register, to avoid conflict with the register, bit and scratchpad internal RAM areas.
The stack pointer, like all registers except DPTR and PC, may hold an 8 bit (1 byte) value. The stack pointer is used to indicate where the next value to be removed from the stack should be taken from.
When you push a value onto the stack, the 89C51 first increments the value of SP and then stores the value at the resulting memory location.

3.1.8 Flash Rom
4Kbyte ROM is available in the microcontroller. It can be erased and reprogrammed. If the available memory is not enough for program we can interface the external ROM with this IC, it has 16-address line, so maximum of (2^16) i.e. 64 bytes of ROM can be interfaced with this microcontroller. Both internal and external ROM cannot be used simultaneously. For external accessing of ROM a pin is provided in microcontroller itself is i.e. pin number 31. EA should be high to use internal ROM, low to use external ROM.
3.1.9 RAM
Internal 256 bytes of RAM are available for the user. These 256 bytes of RAM can be used along with the external RAM. Externally we can connect 64 Kbytes of RAM with microcontroller. In internal RAM first 128 bytes are used as special function register (SFR). These SFRs are used as control registers for timer, serial port, etc.



3.1.9 Register Banks
89C51 use 8 “R” registers, which are used in many of its instructions. These “R” registers are numbered from 0 through 7 (R0, R1, R2, R3, R4, R5, R6 and R7). These registers are generally used to assist in manipulating values and moving data from one memory location to another. For example, to add the value of R4 to the Accumulator, we would execute the following instruction:
ADD A, R4
Thus if the accumulator (A) contained the value 3 and R4 contained the value 3, the Accumulator would contain the value 6 after this instruction was executed. The “R” register is really part of internal RAM.
ADD A, 04h
The instruction adds the value found in Internal RAM address 04h to the value of the Accumulator, leaving the result in the Accumulator. Since R4 is really Internal RAM 04h, the above instruction effectively accomplished the same thing.
The 89C51 has four register banks. When the 89C51 is first booted up, register bank 0 (address 00h through 07h) is used by default. However, our program may instruct the 89C51 to use one of the alternate register banks: I.e., banks 1, 2, or 3. In this case, R4 will no longer be the same as Internal RAM address 04h. For example, if our program instructs the 89C51 to use register bank 3, “R” register R4 will now be synchronous with Internal RAM address 1Ch.
The concept of register banks adds a great level of flexibility to the controller, especially when dealing with interrupts. The register banks really reside in the first 32 bytes of Internal RAM. Register banks can be selected with the help of RS0, RS1 bits in the program status word (PSW).

3.1.10 Thirty-Two Input/Output Pins
All four ports in the 89C51 are bi-directional each contains a latch, an output driver and input buffer. The output drivers of port 0and port 2, and the input buffers of port 0 are used in access to external memory. In this application port 0 is used as a lower byte of the external memory address multiplexed with data bus and port 2 is used as a higher byte of the external memory address when address is sixteen bits wide.
P0 (Port 0, SFR Address 80h, Bit-Addressable):
This is input/output port 0. Each bit of this SFR corresponds to one of the pins on the microcontroller. For e.g., bit 0 of port 0 is pin P0 i.e. pin no. 39 in microcontroller bit 7 is pin P0.7 i.e., pin no. 32 in the IC. Writing a value of ‘1’ to a bit of this SFR will send a high level on the corresponding I/O pin whereas a value of ‘0’ will bring it to a low level.

3.1.11 Interrupts
An interrupt is a special feature, which allows the 89C51 to provide the illusion of “multi-stacking,” although in reality the 89C51 is only doing one thing at a time. The word “interrupt” can often be substituted with the word “event”.
An interrupt is triggered whenever a corresponding event occurs. When the event occurs, the 89C51 temporarily puts “on hold” the normal execution of the program and executes a special selection of code referred to as an interrupt handler. The interrupt handler performs whatever special functions are required to handle the event and then returns control to the 89C51 at which point program execution continues as if it had never been interrupted.
The topic of interrupts is somewhat tricky and very important. For now, suffice to say that interrupts can cause program flow to change.
A computer program has only two ways to determine the conditions that exist in internal external circuits. One method uses software instructions that jump to subroutines on the states of flags and port pins. The second method responds to hardware signals, called interrupts that force the program to call a subroutine. Software techniques use up processor time only when action by the program is needed. Most applications of microcontrollers involve responding to events quickly enough control the environment that generates the events (generically termed real-time programming). Interrupts are often the only way in which real-time programming can be done successfully.
Interrupts may be generated by internal chip operations or provided by external sources. Any interrupt can cause the 89C51 to perform a hardware call to an interrupt, handling subroutine that is located at a predetermined (by the 89C51 designers) absolute address in program memory.
Five interrupts are provided in the 89C51. Three of these are generated automatically by internal operations: Timer flag 0, Timer flag 1, and the serial port interrupt (RI or TI). Two interrupts are triggered by external signals provided by circuitry that is connected to pins INT0 and INT1 (port pins p3.2 and p3.3).
After the interrupt has been handled by the interrupt subroutine, which is placed by the programmer at the interrupt location in program memory, the interrupt program must resume operation at the instruction where the interrupt took place. Program resumption is done by storing the interrupted PC address on the stack in RAM before changing the PC to the interrupt address in ROM. The PC address will be restored from the stack after an RETI instruction is executed at the end of the interrupt subroutine.

3.1.12 Oscillator and clock circuit
This Microcontroller is working in a speed of maximum of 24MHZ. This microcontroller is available with inbuilt oscillator: just we have to connect the crystal to its terminal.

3.1.13 Serial Ports
The serial port is full duplex which means it can transmit and receive simultaneously. It is also received buffered, which means it can begin receiving a second byte before a previously received byte has been read from the receive register. The serial port receive and transmit registers are both accessed as special function register SBUF. Writing to SBUF loads the transmit register and reading SBUF access a physically separate receive register.
SCON (serial control, Address-98h, bit-addressable):
The serial control SFR is used to configure the behavior of the 89C51’s on-board serial port. This SFR controls the baud rate of the serial
Port, whether the serial port is activated to receive data, and also contains flags that are set when a byte is successfully sent or received.
To use the 89C51’s on-board serial port, it is generally necessary to initialize the following SFRs: SCON, TCON, and TMOD. This is because SCON controls the serial port. However, in most cases the program will wish to use one of the timers to establish the serial port’s baud rate. In this case, it is necessary to configure timer 1 by initializing TCON and TMOD. SBUF (Serial Control, Address-99h):

The serial buffer SFR is used to send and receive data via the on-board serial port. Any value written to SBUF will be out the serial port’s TXD pin. Likewise, any value, which the 89C51 receives via the serial port’s RXD pin, will be delivered to the user program via SBUF. In other words, SBUF serves as the output port when written to and as an input port when read from.

3.1.14 Serial Data Input/Output
3.1.15 Computers must able to communicate with other computers in modern multiprocessor distributed systems. One cost-effective way to communication is to send and receive data bits serially. The 89C51 has a serial data communication circuit that uses register SBUF to hold data. Register SCON controls data communication, register PCON controls data rates and pins RXD (P3.0) and TXD (P3.1) connect to the serial data network. SBUF is physically 2 registers. One is writing only and is used to hold data to be transmitted out of the 89C51 via TXD. The other is read only and holds received data from external sources via RXD. Both mutually exclusive registers use address 99h.
There are four programmable modes for serial data communication that are chosen by setting SMX bits in SCONThe serial buffer SFR is used to send and receive data via the on-board serial port. Any value written to SBUF will be out the serial port’s TXD pin. Likewise, any value, which the 89C51 receives via the serial port’s RXD pin, will be delivered to the user program via SBUF. In other words, SBUF serves as the output port when written to and as an input port










The pin details of 89C51 are given in the previous page. Fig 3.1,which will depict the necessary action of the micro controller in the process. The micro controller 89C51 will control 3 solenoid valves, ozone generator & the12V DC motor to a p [erect level, so the water get purified to the nominal amount.
The following algorithm will teach us about how the microcontroller is performing the actions to control 3 solenoid valves, ozone generator, and 12-V dc motor. The next comes is the flower chart which will also depict about the same.

3.2 ALGORITHM
Step 1: Check for low level in storage tank. If low level ON storage tank, check for processing tank low level otherwise kept process OFF.
Step 2: If low level ON processing tank open inlet valve.
Step 3: Check for high level ON storage tank. Stop inflow water.
Step 4: Motor ON. Check for proper motor operation any fault go for error display.
Step 5: After 15 second ON ozone generator for 3 minutes.
Step 6: check for low level ON storage tank. If condition true, open outlet valve.
Step 7: Check for high level if condition satisfied close solenoid valve.
Step 8: Go to step1.
Step 9: Stop.


CHAPTER 4
LEVEL SENSOR

4.1 GENERAL
Level sensor is a level detector, which detects the water level and gives the Signal on to the microcontroller, which will take necessary steps to control The three-solenoid valves, Ozone generator and the pump. It is made of steel and it ions of three-component structure. One steel rod is taken as “HIGH” And the other is taken as “LOW” and the smallest one is taken as “common”.

4.2 STRUCTURE OF LEVEL SENSOR
The figure 4.1in the next page depicts the structure of level sensor. It consists of air bottle drier, ozone generator, solenoid valve and the three level sensors.
The level sensor consists of three terminals. One of them is depicted as ‘LOW’ which is the longest and the next one is depicted as ‘COMMON’ which is shorter and the remaining 0one is depicted as ‘HIGH’ which is the shortest. Of all. When the water level is below the ‘LOW’ LEVEL it is considered as ‘OPEN’ and the water get into the solenoid valve. And when the water touches the ‘HIGH’ point IT IS CONSIDERED AS ‘CLOSE’ and the water will not flow through the solenoid valve.
There are two sets of LEVEL SENSORS in the project. One is placed in the process tank and the remaining one is placed in the normal water tank. The level sensor, which is placed in the PROCESS TANK, is depicted as LEVEL SENSOR1And the other one is taken as LEVEL SENSOR2 and this placed in the normal water tank.











Fig 4.2 Circuit diagram of level sensor




3 CIRCUIT DESCRIPTION
The circuit shown in fig 4.2. Get two kinds of input signals from level sensor.One kind of signal is “LOW” and the other one is “HIGH”.”HIGH” signal is got when the water level is in the saturation point of the tank and the “LOW” signal is got when the water level in the tank is at the bottom point. When the water is at the intermediate point no signal is got from the level sensor.
The diode D1, D2, D3 provides sharp signals to the circuit, and also it provides the one-way path to the circuit. The capacitor C1, C2, C3 that is of 100pf blocks the DC component of the signal and the capacitor C4, C5, C6 boost the voltage about 10% of the input voltage.
The circuit shown in the figure 4.2 acts as a comparator circuit. It compares the signal with the reference signal and gives regarding output signal ton the micro controller. There are two level sensors, so that there are two sets of input signal.
These signals are get isolated from each other. The comparator used in this circuit is HCF40106BE. The details about the HCF40106BE. are given in the APPENDICES.
The Whole project operation depends on the signals given by the level sensor.Level sensor provides secured operation of the project. The input signals from the micro controller is from the 12,13,14,16 pin of the 89C51 and the output signals from the level sensor to the microcontroller 6,7,9 Pin of the micro controller. The resistors of value 100-kilo ohm to 1 mega ohm are used in the input section and the resistors of value 1 mega ohm are used in the output section to control the high current value. The Whole project operation depends on the signals given by the level sensor. Level sensor provides secured operation of the project.





CHAPTER 5 POWER SUPPLY SECTION

5.1 GENERAL
The power supply section supplies the respective type of voltage with accurate magnitude to various components of the project. It consists of step down transformer which gives the about of 12 v &110 v ac. and this is converted to DC voltage and given to respective components. Let us see it in the elaborate manner.

5.2 DESCRIPTION
The figure in the next page shows the circuit diagram of power supply section.The main components of the power section are step down transformer, three relays of 12 V.
Three relays control the operation of three solenoid valves. The three relays get the control signals from the micro controller. The relays are of electromagnetic relays. The capacitor C blocks the DC component of the circuit. The diode D1, D2, D3 gets converts 12V AC to 12V DC and it is Given to the Three relays R1, R2, R3. Here three transistor t1, t2, t3 are used which is used in the common emitter configuration.
The micro controller signals are passed in serious manner to the base of these transistors. The 12V dc is given in a serious manner to the emitter of the transistors and when the microcontroller signals are passed on to the base of the transistors, the 12 V dc is passed on to the solenoid valves and the solenoid valve get opened and thus the water flows from the overhead tank to the processing tank. When the water reaches the ultimate point of the tank, the level sensor circuit Gives the signal to the microcontroller .




CHAPTER 6
ULTIMATE OPERATION OF THE PROJECT

6.1 GENERAL
In this section, we have explained about the main PCB layout, micro controller circuit, the initialization table, tested comparison table, and the overall ultimate operation of the project.

6.2 PROCESS EXPLANATION
Initially, as the power is switched on, a evolutionary sound will take place and the micro controller will give a signal to the relay1 which will pass 230 v dc to the solenoid valve 1 and thus 6the solenoid valve1 get opened, and thus the water get filled up in the process tank from the overhead tank. When the water touches the common point of the level sensor 1 the micro controller switch off the signal which is been given to the relay1, and thus the relay1 get opened and so the solenoid valve1 get closed and thus the flow of water is stopped now, the micro controller will give the signal to the switching ckt1&relay2and thus the 12v dc is given to the motor and so the water get started to circulate through the injector and solenoid valve2. The time taken by the water to reach the injector’s 3 seconds. So the micro controller will pass the signal to the switching ckt2.after 3 seconds. And thus 110 v dc is given to the lot where it is converted t6o 4000 v dc and passes on to the ozone generator and thus the ozone gas get produced and this will flow into the injector. The ozone gas is produced and gets circulated for about 3 minutes.
As the 4000v dc is passed across the ozone generator, o 2 is spited into o & o and by cationic action, it is jointed to o3 and this gas is passed on to the injector.
As the ozone gas get passed into the water, the cell walls of the microbes are ruptured and thus the water get purified with in 3 minutes of time. After 3 minutes of time, micro controller will withdraw its signal, which is given to the switching ckt2. & To the relay2.and so the ozone gas will not be produced and the solenoid valve2 get closed.
Then micrcontroller will give the signal to the relay3 and the solenoid valve 3 gets opened and so the gat moved to the normal water tank, which is available for drinking purpose. When the water level touches the common point of level sensor2, micro controller will withdraw the signal given to the switching ckt1. And thus the motor gets stopped, and the water flow is stopped. The normal water tank is nitrated with the hot water tank at the bottom. So the same level of water is been maintained in the two tanks.
When the water level in the normal water tank is lowered, the level sensor cut get opened, and so the micro controller, will pass on the signal to the switching ckt1, and the motor get started and the water again started to flow from the processing water tank to the normal water tank, and when the water in the processing tank get lowered from the common point, the level sensor cut get opened and the micro controller will pass the signal to the relay1 and thus the solenoid valve 2 get opened and again the process will continued from the initial stage
6.3 COMPONENTS EXPLANATION

6.3.1 Air Drier Bottle
Air drier bottle adds longevity to the ozone generator by absorbing moisture from the atmospheric air. The bottle is filled with silica gel and the color of the material is dark blue, which will fade when it absorbs moisture from 6the atmospheric air. So, silica gel needs to be regenerated after the lifetime.



6.3.2 Ozone generator
Here, expressing oxygen to high voltage discharge produces ozone. When, air flows through ozone generator which contains two electrodes separated by a thin gap at low current and high voltage electric discharge say 4 kV, oxygen is ionized with characteristic bluish glow like lighning.this kind of ozone generator is called carona discharge generator. As the air drawn through the chamber, diatomic oxygen, which is a molecular compound of two oxygen atoms held together by four equally shared electrons, the molecular exciting of oxygen molecules into oxygen take place. Some of these atoms then equally reac6t with oxygen molecules to form ozone. The ozone thus produced is very unstable and converts itself into m0ore stable oxygen.

6.3.3 Motor assembly
Motor assembly is used to shuffle the water stored in the tank with ozone. And also used to discharge the water from the tank after the disinfecting process. For this a 12-v DC motor is used and covered with an ABS material.

6.3.4 Injector
Here the ozone from the ozone generator is injected through a thin capillary tube into the water during disinfecting process. Water gets recycled from the tank.



6.3.5 Solenoid valve
It is a mechanical device in which one way is used to recycle the water from the tank during disinfecting process and the other way is used to draw from storage tank after disinfecting process. When the nylon plunger is pressed one way is closed and the other way opens, when plunger is released one way open and the other way closes.


6.4 BLOCK DIAGRAM DESCRIPTION
The figure 6.2 in next page shows the physical structure of the project. The section, which is provided in central part, is the main section of the project. Central processing unit is nothing but a microcontroller unit. This section controls the whole operation of this project. Other sections are power supply section, pump section, ozone generator section, and level sensor section. We have explained all the section in previous chapter. The circuit diagram & PCB layout of all PCB will be explained following section. Pump assembly uses 12v dc motor.
The condition of the pump will be checked before ON ozone geneator.for this operation 15-second time delay is provided. Any fault in pump assembly will stop the whole operation of the device. At normal operation the motor draw 100mA.
This current is considered as the reference signal for pump comparator. Any change in current will stop t5he whole operation. The circuit diagram & PCB layout of all PCB will be explained following section. Pump assembly uses 12v dc motor.



6.6 CIRCUIT OPERATION
Microcontrolleer gets signal from the level sensor .if the Level Sensor signal is “LOW”, it sends signals to the power supply section to ON the relay of solenoid valve 2.this causes the water inflow to the process tank. When the water level reaches “HIGH” the level sensor sends high signal to the micro controller, for this signal micro controller responds by sending signals to the relay of solenoid valve 1 and to the gate pulse generator of pump. When the gate pulse generator gets the signals from the micro controller it generate gate pulses to turn on Triac.when the Triad get turn on, the pump will be set into operation. The current drawn by the motor is compared with the motor is compared with the reference signal, the comparator the signal to the positive signal too the micro controller. If the pump is operated correctly. Otherwise it sends negative signal and the micro controller stops the whole operation. If the comparator signal is positive, micocontroller sends signals to gate pulse generator of Mosfet of LOT. When MOSFET is triggered ON the LOT get 110V input. And give 4000V output. This output igs given to ozone generator. Ozone generator will generate ozone and get mixed with the rotating water, which is in processing tank. After 3 minutes, the micro controller will stop the signal, which were given to the Mosfet of LOT. Then the micro controller will check the signal of level sensor weather the storage tank is high or not. If the storages tank is high the micro controller will; receive negative signal. Otherwise it will receive positive signal. If it receive positive signal it sends signals to relay of solenoid valve 3.otherwise send signals to the LED for the indication of final stage.microcontroller continuously check the input signal from the level sensor.

6.7 OZONISED MINERAL WATER
Ozone is a blue gas with a relative molar mass of 48 and molecular formula of O3.It converts back into oxygen after its oxidizing process. This makes it the most eco-friendly treatment known today. Ozone is the ultimate in disinfections. When drinking water is treated with chlorine (chlorine is a highly carcinogenic chemical), the residual chlorine in water is also consumed along with the water. On the water hand zone, having half the life of only about 20 minutes, unrelated ozone reduces to oxygen, leaving no trace of toxicity in water. The water is free from chlorine. Ozone reacts with impurities such as microorganisms including bacteria, virus, spores, mould, and fungi. As ozone destroys all micro of organisms and it removes disagreeable odors, the resultant water is absolutely safe, pure, fresh and healthy. Ozonised water is colorless and odourless. The advantage of the use of ozone in water is that it does not leave a dangerous chemical residue like many conventional treating chemicals.



6.8 INITIALISATION PROCEDURE
The system is initialized in two steps using six-pole dipswitch. The initialization method was shown in table 3.1 and 3.2.First step is to set the processing time and air drier capacity. Second step is to set the reprocessing interval, model and reprocessing time. This step is not effective during normal operation.

6.8.1 First step
1. Put the power OFF
2. Set Switch 1 ON
3. Set Switches 3 and 4 according to processing time

For 3 min. 3-OFF 4-OFF
For 4 min. 3-ON 4-OFF
For 5 min 3-OFF 4-ON
For 6 min 3-ON 4-ON
4. Set switches 5 and 6 to program air drier capacity
For 60 hrs. 5-ON 6-ON
For 70hrs. 5-OFF 6-ON
For 80hrs. 5-OFF 6-OFF
For 100hrs. 5-ON 6-OFF
5. After setting switches 3,4,5 and 6 as per, the requirement, put the power ‘ON’. In Two seconds ‘safe water’ green LED lights ON.
6. Put the power OFF.



6.8.2 Second step
1. Put the power OFF
2. Set switches 1 and 2 ON
3. Set switches 3 and 4 as per the required reprocessing interval
4. Set switches 5 and 6 to configure the model
a) For wd2, wd4 5-OFF 6-OFF
b) For lwd2, lwd3, lwd4 5-ON 6-OFF
At jumper j1 2 & 3 short
c) For m+wd2, m+wd3, m+wd4 5-ON 6-OFF
J1 2 & 3
d) For double tank models
At jumper j1 & 2short 5-OFF 6-ON
5.Now put the power OFF
6.All the six switches are put OFF
The initialization is over. Now the switches 3,4,5 and 6 are set again as per the required again as per the processing time and air drier capacity.


6.9 HEAT WATER SECTION
The fig 6.4.shows the functional block diagram of the heater sections. It consists of three sections. They are relay, thermostat, and heater. Get input from microcontroller. Microcontroller sends signals regarding the signals from level sensor. T protects the heater from heating of heater without water. So those, relay action is necessary to protect the heater from burning. The section with in dashed lines should be sinking in water. Thermostat is used to keep the temperature level at specified level. We can change the temperature level as per our required. Heater is supplied with separate power supply. The supply level is 230v ac.



CHAPTER 7
CONCLUSION
As all we know that water is the ultimate source of life, we made a project which gives pure water at all times .the project will be in good mode in the Salem zone only. When the project is placed out of the Salem zone, the purity of the water will be low as the underground water contents will from one place to other place. Particularly, it is designed to purify the Salem zone underground water. So, this project5 can be made usable at all places with Best efficiency, by establishing REVERSE OSMOSIS with this project. The overall cost of this project is Rs .7000 /- only.

11 comments:

srinivas said...

hi i want to do this project can u help me pls

srinivas said...

im a final year student of EIE need some process instrumentation related project pls help

Anonymous said...

hi
can i use this idea for my project?

ICPL Initiative Chemicals Pvt. Ltd said...

ICPL Group, Delhi (India) based water treatment chemicals supplier offering chemicals for boiler water treatment , cooling water treatment , industrial water, drinking water and other water impurities.

aparna said...

could you please give me the entire report of the project.......

Electro Chlorination System said...

Thanks for your information. ByChlorine generators

nikhil cb said...

What do you think of this Water Purifier? Looking for a decent system for home use HUL Pure It/

Lovisa smith said...

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uv water purifier

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Aquafreshro Systems said...

Very nice information.Keep it up..

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