مجموعة تكنولاب البهاء جروب

تحاليل وتنقية ومعالجة المياه
 
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معمل تكنولاب البهاء جروب
 للتحاليل الكيميائية والطبية
والتشخيص بالنظائر المشعة
 للمخدرات والهرمونات والسموم
 وتحاليل المياه

مجموعة
تكنولاب البهاء جروب
لتصميم محطات الصرف الصناعى والصحى
لمعالجة مياه الصرف الصناعى والصحى
مجموعة تكنولاب البهاء جروب
المكتب الاستشارى العلمى
دراسات علمية كيميائية



معالجة الغلايات وانظمة البخار المكثف
معالجة ابراج التبريد المفتوحة
معالجة الشيللرات
مجموعة تكنولاب البهاء جروب
اسنشاريين
كيميائيين/طبيين/بكترولوجيين
عقيد دكتور
بهاء بدر الدين محمود
رئيس مجلس الادارة
استشاريون متخصصون فى مجال تحاليل وتنقية ومعالجة المياه
متخصصون فى تصنيع وتصميم كيماويات
معالجة الصرف الصناعى والصحى
حسب كل مشكلة كل على حدة
تصنيع وتحضير كيماويات معالجة المياه الصناعية
مؤتمرات/اجتماعات/محاضرات/فريق عمل متميز
صور من وحدات معالجة المياه


technolab el-bahaa group
TECHNOLAB EL-BAHAA GROUP
EGYPT
FOR
WATER
TREATMENT/PURIFICATION/ANALYSIS
CONSULTANTS
CHEMIST/PHYSICS/MICROBIOLIGIST
 
INDUSTRIAL WATER
WASTE WATER
DRINKING WATER
TANKS CLEANING
 
CHAIRMAN
COLONEL.DR
BAHAA BADR EL-DIN
0117156569
0129834104
0163793775
0174041455

 

 

 

تصميم وانشاء محطات صرف صناعى/waste water treatment plant design

technolab el-bahaa group
egypt
We are a consultants in water treatment with our chemicals as:-
Boiler water treatment chemicals
Condensated steam treatment chemicals
Oxygen scavenger treatment chemicals
Ph-adjustment treatment chemicals
Antiscale treatment chemicals
Anticorrosion treatment chemicals
Open cooling tower treatment chemicals
Chillers treatment chemicals
Waste water treatment chemicals
Drinking water purification chemicals
Swimming pool treatment chemicals
Fuel oil improver(mazote/solar/benzene)
technolab el-bahaa group
egypt
We are consultants in extraction ,analysis and trading the raw materials of mines as:-
Rock phosphate
32%-30%-28%-25%
Kaolin
Quartez-silica
Talcum
Feldspae(potash-sodumic)
Silica sand
Silica fume
Iron oxid ore
Manganese oxid
Cement(42.5%-32.5%)
Ferro manganese
Ferro manganese high carbon

 

water treatment unit design


 

وكلاء لشركات تركية وصينية لتوريد وتركيب وصيانة الغلايات وملحقاتها
solo agent for turkish and chinese companies for boiler production/manufacture/maintance

 

وكلاء لشركات تركية وصينية واوروبية لتصنيع وتركيب وصيانة ابراج التبريد المفتوحة

 

تصميم وتوريد وتركيب الشيللرات
design/production/maintance
chillers
ابراج التبريد المفتوحة
مجموعة تكنولاب البهاء جروب
المكتب الاستشارى العلمى
قطاع توريد خطوط انتاج المصانع
 
نحن طريقك لاختيار افضل خطوط الانتاج لمصنعكم
سابقة خبرتنا فى اختيار خطوط الانتاج لعملاؤنا
 
1)خطوط انتاج العصائر الطبيعية والمحفوظة والمربات
2)خطوط انتاج الزيوت الطبيعية والمحفوظة
3)خطوط انتاج اللبن الطبيعى والمحفوظ والمبستر والمجفف والبودرة
4)خطوط تعليب وتغليف الفاكهة والخضروات
5)خطوط انتاج المواسير البلاستيك والبى فى سى والبولى ايثيلين
6)خطوط انتاج التراى كالسيوم فوسفات والحبر الاسود
7)خطوط انتاج الاسفلت بانواعه
Coolمحطات معالجة الصرف الصناعى والصحى بالطرق البيولوجية والكيميائية
9)محطات معالجة وتنقية مياه الشرب
10)محطات ازالة ملوحة البحار لاستخدامها فى الشرب والرى
11)الغلايات وخطوط انتاج البخار الساخن المكثف
12)الشيللرات وابراج التبريد المفتوحة وخطوط انتاج البخار البارد المكثف
 
للاستعلام
مجموعة تكنولاب البهاء جروب
0117156569
0129834104
0163793775
 
القاهرة-شارع صلاح سالم-عمارات العبور-عمارة 17 ب
فلا تر رملية/كربونية/زلطيه/حديدية

وحدات سوفتنر لازالة عسر المياه

مواصفات مياه الشرب
Drinking water
acceptable
values

50

colour

acceptable

Taste

nil

Odour

6.5-9.2

ph

 

1 mg/dl

pb

5 mg/dl

as

50 mg/dl

cn

10 mg/dl

cd

0-100mg/dl

hg

8 mg/dl

f

45 mg/dl

N02

1 mg/dl

Fe

5 mg/dl

Mn

5.1 mg/dl

Cu

200 mg/dl

Ca

150 mg/dl

Mg

600 mg/dl

Cl

400 mg/dl

S04

200 mg/dl

Phenol

15 mg/dl

zn

 

 

الحدود المسموح به
ا لملوثات الصرف الصناعى
 بعد المعالجة
Acceptable
values
treated wate water
7-9.5

ph

25-37 c

Temp

40 mg/dl

Suspended solid

35 mg/dl

bod

3 mg/dl

Oil & grase

0.1 mg/dl

hg

0.02 mg/dl

cd

0.1 mg/dl

cn

0.5mg/dl

phenol

1.5 ds/m

conductivity

200 mg/dl

na

120 mg/dl

ca

56 mg/dl

mg

30 mg/dl

k

200 mg/dl

cl

150 mg/dl

S02

0.75 mg/dl

Fe

0.2 mg/dl

Zn

0.5 mg/dl

Cu

0.03 mg/dl

Ni

0.09 mg/dl

Cr

0.53 mg/dl

لb

0.15 mg/dl

pb

 





pipe flocculator+daf
plug flow flocculator
lamella settels

محطات تحلية مياه البحر بطريقة التقطير الومضى على مراحل
MSF+3.jpg (image)
محطات التقطير الومضى لتحلية مياه البحر2[MSF+3.jpg]
some of types of tanks we services
انواع الخزانات التى يتم تنظيفها
ASME Specification Tanks
Fuel Tanks
Storage Tanks
Custom Tanks
Plastic Tanks
Tank Cleaning Equipment
Double Wall Tanks
Septic Tanks
Water Storage Tanks
Fiberglass Reinforced Plastic Tanks
Stainless Steel Tanks
Custom / Septic
مراحل المعالجة الاولية والثانوية والمتقدمة للصرف الصناعى

صور مختلفة
من وحدات وخزانات معالجة الصرف الصناعى
 التى تم تصميمها وتركيبها من قبل المجموعة

صور
 من خزانات الترسيب الكيميائى والفيزيائى
 لوحدات معالجة الصرف الصناعى
المصممة من قبل المحموعة



technolab el-bahaa group


technolab el-bahaa group


technolab el-bahaa group

technolab el-bahaa group


technolab el-bahaa group


technolab el-bahaa group


technolab el-bahaa group


technolab el-bahaa group


technolab el-bahaa group


technolab el-bahaa group




مياه رادياتير اخضر اللون
بريستول تو ايه
انتاج شركة بريستول تو ايه - دمياط الجديدة
مجموعة تكنولاب البهاء جروب

اسطمبات عبوات منتجات شركة بريستول تو ايه-دمياط الجديدة

مياه رادياتير خضراء فوسفورية

من انتاج شركة بريستول تو ايه 

بترخيص من مجموعة تكنولاب البهاء جروب


زيت فرامل وباكم

DOT3



شاطر | 
 

 boilers by hager mandour

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عدد المساهمات : 3596
تاريخ التسجيل : 15/09/2009
العمر : 50
الموقع : مصر

مُساهمةموضوع: boilers by hager mandour   الجمعة أكتوبر 23, 2009 11:32 am

BOILERS

A boiler is an enclosed vessel that provides a means for combustion heat to be transferred into water until it becomes heated water or a gas (steam). The steam or hot water under pressure is then usable for transferring the heat to a process. Water is a useful and cheap medium for transferring heat to a process. When water is boiled into steam its volume increases about 1,600 times, producing a force that is almost as explosive as gunpowder. This causes the boiler to be an extremely dangerous item that must be treated with utmost respect.
The process of heating a liquid until it reaches it's gaseous state is called evaporation. Heat is transferred from one body to another by means of:
(1) Radiation, which is the transfer of heat from a hot body to a cold body through a conveying medium without physical contact.
(2) Convection, the transfer of heat by a conveying medium, such as air or water.
(3) Conduction, transfer of heat by actual physical contact, molecule to molecule.
The heating surface is any part of the boiler metal that has hot gases of combustion on one side and water on the other. Any part of the boiler metal that actually contributes to making steam is heating surface. The amount of heating surface a boiler has is expressed in square feet. The larger the amount of heating surface a boiler has the more efficient it becomes. The measurement of the steam produced is generally in pounds of water evaporated to steam per hour.
BOILER TYPES:

There are virtually infinite numbers of boiler designs but generally they fit into one of two categories:
(1) Firetube or as an easy way to remember "fire in tube" boilers, contain long steel tubes through which the hot gasses from a furnace pass and around which the water to be changed to steam circulates
(2) Watertube or "water in tube" boilers in which the conditions are reversed with the water passing through the tubes and the furnace for the hot gasses is made up of the water tubes.
In a firetube boiler the heat (gasses) from the combustion of the fuel passes through tubes and is transferred to the water which is in a large cylindrical storage area. Common types of firetube boilers are scotch marine, firebox, HRT or horizontal return tube. Firetube boilers typically have a lower initial cost, are more fuel efficient and easier to operate. Fire-tube boilers usually have a comparatively low rate of steam production, but high steam storage capacity. Watertube boilers generally give high steam production rates, but less storage capacity than the above. Large watertube boilers used in industries with large steam demands
The more common types of watertube boilers are "D" type, "A" type, "O" type, bent tube, and cast-iron sectional.



Firetube Scotch Marine Boiler




A boiler operates using the feedwater system, the steam system, the fuel system and the draft system.
Makeup water is the water supplied from the municipal water system, well water, or other source for the addition of new water to the boiler system necessary to replace the water evaporated.
To remove the solids that continues to the boiler chemicals are added to react with the solids creating sludge. This sludge is then periodically removed by opening valves from the bottom of the boiler and relieving it to the drain. This process is called blowdown.
Water, steam fittings and accessories are required to supply and control water and steam in the boiler. Boiler fittings or trim are components such as valves directly attached to the boiler. Accessories are pieces of equipment not necessarily attached to the boiler, but required for the operation of the boiler.
Water fittings and accessories control the amount, pressure and temperature of water supplied to and from the boiler. Water in the boiler must be maintained at the normal operating water level or NOWL. Low water conditions can damage the boiler and could cause a boiler explosion. High water conditions can cause carryover. Carryover occurs when small water droplets are carried in steam lines. Carryover can result in water hammer. Water hammer is a banging condition caused by hydraulic pressure that can damage equipment.
Steam Fittings & Accessories remove air, control steam flow, and maintain the required steam pressure in the boiler. Steam fittings are also used to direct steam to various locations for heating and process.

Boiler fittings & Accessories:
• Safety Valves are the most important fittings on the boiler. They should open to release pressure when pressure inside the boiler exceeds the maximum allowable working pressure or MAWP. Safety valves are installed at the highest part of the steam side of the boiler. No other valve shall be installed between the boiler and the safety valve. Safety valve capacity is measured in the amount of the steam that can be discharged per hour. The safety valve will remain open until sufficient steam is released and there is a specific amount of drop in pressure. This drop in pressure is the blowdown of the safety valve.

• Feedwater Valves control the flow of feedwater from the feedwater pump to the boiler. Feedwater stop valves are globe valves located on the feedwater line. They isolate the boiler from feedwater accessories. The feedwater stop valve is positioned closest to the boiler to stop the flow of water out of the boiler for maintenance, or if the check valve malfunctions. The feedwater check valve is located next to the feedwater stop valve and prevents feedwater from flowing from the boiler back to the feedwater pump. The feedwater check valve opens and closes automatically with a swinging disc. When water is fed to the boiler it opens. If water flows back from the boiler the valve closes.

• Gage Glass is used to visually monitor the water level in the boiler. Isolation valves located at the top and bottom permit the changing of gage glasses. Tubular gage glasses are used for pressure up to 400 psig. All boilers must have two methods of determining the boiler water level. The gage glass serves as the primary method of determining boiler water level. If the water cannot be seen in the gage glass, the tricocks are used as a secondary method of determining boiler water level. The middle tricock is located at the NOWL. If water comes out of the middle tricock, the gage glass is not functioning properly. If water comes out of the top tricock, there is a high water condition in the boiler. If water comes out of the bottom tricock, water may be safely added to the boiler. If steam comes out of the bottom tricock, water must not be added to the boiler. Secure the fuel immediately. Adding water could cause a boiler explosion.

• Water Column minimizes the water turbulence in the gage glass to provide accurate water level reading. Water columns are located at the NOWL, with the lowest part of the water column positioned at least 3" above the heating system. Water columns for high pressure boilers consist of the main column and three tricocks. High and low water alarms or whistles may be attached to the top and bottom tricocks.

• Makeup Water replaces boiler water lost from leaks or from the lack of condensate returned in the boiler. Makeup water is fed manually or automatically. Boilers can have both manual and automatic systems. If the boiler has both, the manual always bypasses the automatic system. Boiler operators must know how to supply makeup water quickly to the boiler in the event of a low water condition. Manual systems feed city water with a hand operated valve. Automatic systems feed city water with a float control valve mounted slightly below the NOWL. If the float drops from a low water level, the valve in the city water line is open. As the water level rises, the float rises to close the valve.

• The Low Water Fuel Cut Off shuts off fuel to the burner in the event of a low water condition in the boiler. The low water fuel cut off is located 2" to 6" below the NOWL. Low water fuel cut offs are available with or without an integral water column. Low water fuel cut offs must be tested monthly or more often depending on plant procedures and requirements.

• The Feedwater Regulator maintains the NOWL in the boiler by controlling the amount of condensate return pumped to the boiler from the condensate return tank. The correct water level is maintained with a feedwater regulator, but boiler water level must still be checked periodically by the boiler operator.

• Feedwater Pumps are used with feedwater regulators to pump feedwater to the boiler. Pressure must be sufficient to overcome boiler water pressure to maintain the NOWL in the boiler. Feedwater pumps may be reciprocating, centrifugal or turbine. Reciprocating feedwater pumps are steam driven and use a piston to discharge water to the feedwater line. They are limited in capacity and are used on small boilers. Centrifugal feedwater pumps are electric motor or steam driven. They are the most common feedwater pump. Centrifugal force moves water to the outside edge of the rotating impeller. The casing directs water from the impeller to the discharge piping. Discharge pressure is dependent on impeller speed. Turbine feedwater pumps are steam driven and operate similarly to centrifugal feedwater pumps.

• Feedwater Heaters heat water before it enters the boiler drum to remove oxygen and other gases which may cause corrosion.

• Bottom Blowdown Valves release water from the boiler to reduce water level, remove sludge and sediment, reduce chemical concentrations or drain the boiler. Two valves are commonly used, a quick opening and screw valve. During blowdown the quick opening valve is opened first, the screw valve is opened next .Water is discharged to the blowdown tank. A blowdown tank collects water to protect the sewer from the hot boiler water. After blowdown, the screw valve is closed first and the quick opening valve is closed last.

• Steam Pressure Gages and vacuum gages monitor pressure inside the boiler. The range of these gages should be 1-1/2 to 2 times the MAWP of the boiler. For example: on a low pressure boiler, a maximum steam pressure on the pressure gage reads 30 psig as the MAWP is 15 psig.

• Steam Valves commonly used include a gate valve used for the main steam stop valve and the globe valve. The main steam stop valve cuts the boiler in online allowing steam to flow from the boiler or takes it off line. This is an outside stem and yoke or OS&Y valve. The position of the stem indicates whether the valve is open or closed. The valve is opened with the stem out and closed with the stem in. This provides quick information to the boiler operator. The globe valve controls the flow of steam passing under the valve seat through the valve. This change in direction causes a decrease in steam pressure. A globe valve decreases steam flow and can be used to vary the amount of steam flow. This should never be used as a main steam stop valve.

• Steam Traps remove condensate from steam in lines from the boiler. Steam traps work automatically and increase boiler plant efficiency. They also prevent water hammer by expelling air and condensate from the steam lines without loss of steam. Steam traps are located after the main steam header throughout the system. Steam traps commonly used include the inverted bucket, the thermostatic and the float thermostatic. In the inverted bucket steam trap steam enters the bottom flowing into the inverted bucket. The steam holds the bucket up. As condensate fills the steam trap the bucket loses buoyancy and sinks to open the discharge valve. The thermostatic steam trap has a bellows filled with a fluid that boils at steam temperature. As the fluid boils vapors expand the bellows to push the valve closed. When the temperature drops below steam temperature, the bellows contract to open the valve and discharge condensate. A variation of the thermostatic steam trap is the float thermostatic steam trap. A float opens and closes depending on the amount of condensate in the trap bowl. Condensate is drawn out by return vacuum.

• Steam Strainers remove scale or dirt from the steam and are located in the piping prior to steam trap inlet. Scale or dirt can clog discharge orifices in the steam trap. Steam strainers must be cleaned regularly.

Fuel system:

The fuel system includes all equipment used to provide fuel to generate the necessary heat. The equipment required in the fuel system depends on the type of fuel used in the system. All fuels are combustible and dangerous if necessary safety standards are not followed. Fuels commonly used are: Natural Gas, Oil, Coal, Wood and electricity.

Draft system:

The draft system regulates the flow of air to and from the burner. For fuel to burn efficiently the right amount of oxygen must be provided. Air must also be provided to direct the flow of air through the furnace to direct the gases of combustion out of the furnace to the breaching. A forced draft system uses a fan to force (or push) air through the furnace. An induced draft system uses a fan to draw (or pull) air through the furnace. A combination or balanced draft system uses forced and induced draft fans. Gases of combustion enter the stack from the breaching and are released to the atmosphere.

COMBUSTION & CONTROLS:

This is the method of combining the fuel and air systems in a source of heat at sufficient temperature to produce steam. Combustion may be defined as the rapid chemical combination of oxygen with the combustible elements of a fuel. Only three combustible, chemical elements are of any significance: carbon, hydrogen and sulfur. The boiler combustion furnace in which the fuel burns provides a chamber in which the combustion reaction can be isolated and confined so that it can be controlled. In a scotch marine boiler it is referred to as a Morrison tube or in other boilers the firebox area.

10 Air (O2) + 1 Gas = CO2 + 2H2O + 8N2 + Heat

The objective of good combustion is to release all of the heat in the fuel. This is accomplished by controlling the "three T's" of combustion which are
(1) Temperature high enough to ignite and maintain ignition of the fuel.
(2) Turbulence or mixing of the fuel and oxygen.
(3) Time sufficient for complete combustion.
The burner is the principal device for the firing of the fuel. Burners are normally located in the vertical walls of the furnace. The amount of fuel supplied to the burner must be in proportion to the steam pressure and the quantity of steam required.
A drop in steam pressure necessitates an increase in the fuel supplied to the burner. Conversely, an increase in steam pressure necessitates a decrease in the fuel supplied.
To maintain high combustion efficiency, the air to fuel ratio must be balanced from the lowest firing rate to the highest firing rate. If there is an imbalance in the air to fuel ratio, smoking, flame failure, wasted fuel and in extreme cases an explosion could result. A consistent firing rate reduces fluctuation of the boiler water level and increases the life of the boiler drum and tubes.

The programmer is the mastermind that controls the starting sequence and firing cycle of a burner. The programmer controls the operation sequence of the blower, burner motor, ignition system, fuel valve, and all other components of the ON/OFF control system.

The programmer also provides a suitable purge period before ignition and after burner shutdown when explosive combustibles are removed. The programmer is designed to deenergize all fuel valves within 4 seconds after loss of the flame signal. In addition, the programmer automatically restarts a new cycle each time the pressure control closes or after a power failure, but locks out and must be reset manually after any flame failure. A burner must always start in low fire and shut down in low fire which prevents wasting fuel and reduces the possibility of a flareback when excess fuel accumulates in the furnace.

The pressure control regulates the operating range of the boiler by modulating the burner on boiler steam pressure demand. The pressure control is installed using a siphon to protect the bellows from the high temperature of steam. The pressure control sends signals to the modulating motors.

Modulating motors use conventional mechanical linkage or electric valves to regulate the primary air, secondary air, and fuel supplied to the burner.

The boiler water level control is a safety feature which will shut the boiler off if the water level drops to an unacceptable level. Boilers have two water level controllers as a safety feature in case one fails. The two level controllers are also set at different levels with the controller at the higher level sounding an alarm and the controller at the lower level actually shutting down the boiler. Boiler level controls may be a float type as pictured at right or a probe type which operates by testing for conductivity to determine if the water level is adequate.

The Control firing sequence occurs at cold startup or when the steam pressure drops, the pressure control completes an electric circuit, which starts a timer motor cam turning in the programmer. The first contact on the timer motor cam closes and starts the burner motor that rotates the primary air fan. The primary air fan blows air into the furnace to purge any unburned fuel present in a gaseous condition. This process is called prepurging the furnace. By prepurging the furnace before pilot ignition, the danger of a furnace explosion is reduced. Depending upon the size of the furnace the purge cycle takes approximately 30 seconds but may take as long as 60 seconds. The programmer is still operating and when the second contact closes, the circuit of the ignition transformer is completed. This causes a spark in front of the gas pilot tube. At the same time, a solenoid valve is opened in the gas pilot line, allowing gas to flow through the gas pilot tube and be ignited by the spark. The scanner is located on the front of the boiler and is used to sight the pilot. Sighting the pilot through the scanner will verify that the pilot is lit. This process is referred to as proving pilot. The next step is to close the contact which completes the circuit to the main fuel valve, which opens only after the scanner has proved pilot. With the main fuel valve open the fuel enters the furnace and is ignited by the pilot. The scanner is then used to prove the main flame. The programmer continues to operate for a few more seconds, securing circuits to the ignition transformer and the gas pilot. After the circuits are secured, the programmer stops. The burner is now regulated by the pressure control and the modulating pressure control. If the scanner senses a flame failure, the system is purged and secured. The programmer is then manually reset to the start cycle.

STEAM TO WATER CYCLE:

The feedwater system provides water to the boiler and regulates it automatically to meet the demand for steam. Valves provide access for maintenance and repair.
The steam system collects and controls the steam produced in the boiler. Steam is directed through piping to the point of use. Throughout the system steam pressure is regulated using valves and checked with steam pressure gauges.
The two sources of feedwater are:
(1) Condensate. Or condensed steam returned from the processes
(2) Makeup water (usually city water) which must come from outside the boiler room and plant processes.
For higher boiler efficiencies the feedwater can be heated, usually by economizers.



A. WATER SOFTENERS:

Hardness is composed primarily of calcium (Ca) and magnesium (Mg) but also to lesser amounts sodium (Na), potassium (P), and several other metals. All softeners soften or remove the hardness from the water. The primary minerals in the water that make "hard" water are Calcium (Ca++) and Magnesium (Mg++). They form a curd with soap and scale in piping, water heaters and whatever the hard water contacts. Hardness is removed from the water by a process known as positive ion exchange. This process could also be known as "ion substitution", for substitution is what occurs. Sodium (Na+) ions, which are "soft" are substituted or exchanged for the Calcium and Magnesium as the water passes through the softener tank.



The softening media is commonly called resin or Zeolite. The proper name for it is polystyrene resin. The resin has the ability to attract positive charges to itself. The reason it does so is because in its manufacture it inherits a negative charge. It is a law of nature that opposite charges attract, i.e., a negative will attract a positive and vice versa. A softener tank contains hundreds of thousands of Zeolite beads. Each bead is a negative in nature and can be charged or regenerated with positive ions. In a softener, the Zeolite is charged with positive, "soft" sodium ions.
As "hard" water passes through the Zeolite, the Calcium and Magnesium ions are strongly attracted to the beads. As the "hard" ions attach to the Zeolite bead, they displace the "soft" Sodium ions that are already attached to the bead. In effect, the Sodium is "exchanged" for the Calcium and Magnesium in the water supply with the Calcium and Magnesium remaining on the Zeolite beads and the Sodium ions taking their place in the water flowing through the softener tank. The result of this "exchange" process is soft water flowing out of the tank.
It can now be readily understood that a softener will continue to produce "soft" water only as long as there are Sodium ions remaining on the Zeolite beads to "exchange" with the Calcium and Magnesium ions in the "hard" water. When the supply of Sodium ions has been depleted, the Zeolite beads must be "regenerated" with a new supply of Sodium ions. The regeneration of the Zeolite beads is accomplished by a three step process.

REGENERATION PROCESS:

BACKWASH:
The flow of water through the mineral bed is reversed. The mineral bed is loosened and accumulated sediment is washed to the drain by the upward flow of the water. An automatic backwash flow controller maintains the proper flow rate to prevent the loss of resin.

BRINE DRAW AND SLOW RINSE:
Ordinary salt has the capability to restore the exchange capacity of the mineral. A given amount of salt-brine is rinsed slowly through the mineral bed. After the salt-brine is drawn, the unit will continue to rinse slowly with water to remove all of the salt-brine from the media bed.



FAST RINSE:
A high down flow of water repacks the mineral bed. Any trace of brine not removed in slow rinse is flushed to the drain.
The unit is then returned to SERVICE the brine maker is refilled with fresh water to form salt brine for the next regeneration. The total regeneration time is approximately 60-90 minutes.

SOFTENER DESIGN:

Water softeners come as single mineral tank units (simplex), double mineral tank units (duplex) and multiple mineral tank units. Since regeneration cycles can take approximately one hour simplex units are used only when this interruption can be tolerated. To avoid interruption duplex units are used so that the regeneration of one unit can be accomplished while the second unit is on line. Triplex or other multiplex units usually are the result of need for increased capacity and units can be added to keep soft water available.




B. DEAERATION:

All natural waters contain dissolved gases in solution. Certain gases, such as carbon dioxide and oxygen, greatly increase corrosively. When heated in boiler systems, Carbon dioxide (CO2) and oxygen (O2) are released as gases and combine with water (H2O) to form carbonic acid, (H2CO3).

CO2 + O2 + H2O > H2CO3

Removal of oxygen, carbon dioxide and other non-condensable gases from boiler feedwater is vital to boiler equipment longevity as well as safety of operation. Carbonic acid corrodes metal reducing the life of equipment and piping. It also dissolves iron (Fe) which when returned to the boiler precipitates and causes scaling on the boiler and tubes. This scale not only contributes to reducing the life of the equipment but also increases the amount of energy needed to achieve heat transfer.
The term given to the mechanical removal of dissolved gases is deaeration. Mechanical deaeration for the removal of these dissolved gases is typically utilized prior to the addition of chemical oxygen scavengers. Mechanical deaeration is based on Charles' and Henry's laws of physics. Simplified, these laws state that removal of oxygen and carbon dioxide can be accomplished by heating the boiler feedwater which reduces the concentration of oxygen and carbon dioxide in the atmosphere surrounding the feedwater.

The easiest way to deaerate is to force steam into the feedwater, this action is called scrubbing. Scrubbing raises the water temperature causing the release of O2 and CO2 gases that are then vented from the system. In boiler systems, steam is used to "scrub" the feedwater as:
(1) Steam is essentially devoid of O2 and CO2.
(2) Steam is readily available.
(3) Steam adds the heat required to complete the reaction.

For efficient operation, deaerating equipment must satisfy the following requirements:
(1) Heating of the feedwater: The operating temperature in the unit should be the boiling point of water at the measured pressure. The pressure/temperature relationship is important since boiling must take place rapidly for quick and efficient removal of gases. If this temperature and pressure cannot be economically achieved then it is important to get as close to it as possible.
(2) Agitation decreases the time and heat energy necessary to remove dissolved gases from the water.
(3) Maximization of surface area by finely dispersing the water to expose maximum surface area to the steam. This enables the water to be heated to saturation temperature quicker and reduces the distance the gases have to travel to be liberated.
(4) The liberated gases must be vented to allow their escape from the system as they are released.

While the most efficient mechanical deaerators reduce oxygen to very low levels (.005cc/l or 5 ppb), even trace amounts of oxygen may cause corrosion damage to a system. Consequently, good operating practice requires removal of that trace oxygen with a chemical oxygen scavenger such as sodium sulfite or hydrazine. Free carbon dioxide can be removed by deaeration, but this process releases only small amounts of combined carbon dioxide. The majority of the combined carbon dioxide is removed with the steam of the boiler, subsequently dissolving in the condensate, frequently causing corrosion problems. These problems can be controlled through the use of volatile neutralizing amines or filming amines.

TYPES OF MECHANICAL DEAERATORS:

1. Tray Type Deaerators are composed of a deaerating section and a feedwater storage section. Incoming water is sprayed through a perforated distribution pipe into a steam atmosphere where it is atomized. There it is heated to within a few degrees of the saturation temperature of the steam. Most of the non-condensable gases are released to the steam as the water enters the unit. The water then cascades through the tray section, breaking into fine droplets, which immediately contact incoming steam. The steam heats the water to the saturation temperature of the steam and removes all but a trace of oxygen. Deaerated water falls to the feedwater storage section below and is protected from recontamination by a blanket of steam. As the non-condensable gases are liberated, they as well as a small amount of steam are vented to atmosphere. It is essential that sufficient venting is provided at all times or deaeration will be incomplete.

2. Spray Type Deaerators work on the same general principle as the tray types. The spray type deaerators do not use trays for dispersion of the water. In this case, spring loaded nozzles located in the top of the unit spray water into a steam atmosphere which is heated to within a few degrees of the saturation temperature of the steam. Most of the non-condensable gases are released to the steam, and the heated water falls to a water seal and drains to the lowest section of the steam scrubber.
3. Spray/Tray Type Deaerators are a combination of the above with a steam spray nozzle sending the water over the trays.
4. Feedwater Tanks are another form of mechanical deaerators normally found in small firetube and watertube boiler systems due to cost considerations. These less expensive systems are limited by design as they are operated at atmospheric pressure with feedwater temperatures ranging from 1800F - 2120F; while deaerators operate under pressure allowing for higher temperatures and more efficient oxygen removal. Like deaerators, feedwater tanks operate by forcing steam into the feedwater which scrubs oxygen and carbon dioxide gases that are then vented to atmosphere.

C. ECONOMIZER:

An economizer removes additional Btu’s from the stack gasses by circulating the deaerated boiler feedwater through a series of bent tubes in the stack. This translates into a "free" source of energy from the boiler operation. Finned tube economizers are less costly and more efficient as the "fins" are a source of heat transfer as well as the tubes. An economizer can also be a useful means of increasing the steam capacity of a boiler.


DEPOSIT CONTROL:

Deposits in boilers may result from hardness contamination of feedwater, and corrosion products from the condensate and feedwater system. Hardness contamination of the feedwater may result from either deficient softener systems or raw water in leakage of the condensate. Deposits act as insulators and slow heat transfer. The insulating effect of deposits causes the boiler metal temperature to rise and may lead to tube-failure by overheating. Large amounts of deposits throughout the boiler could reduce the heat transfer enough to reduce the boiler efficiency.
When feedwater enters the boiler, the elevated temperatures and pressures cause the components of water to take on dramatic changes. Most of the components in the feedwater are soluble; they are dissolved in the water. However, under heat and pressure most of the soluble components come-out of solution as particulate solids, sometimes in crystallized forms and other times as amorphous particles. The coming-out of solution is referred to as retrograde solubility, and means that as temperature increases, ability to stay in solution decreases. When solubility of a specific component in water is exceeded, scale or deposits develop.
Internal chemical treatment for deposit control is achieved either by adding a treatment to prevent the contaminants from depositing or by adding a treatment chemical that will allow for easy removal by blowdown. Hardness can be kept from depositing in boiler water by treatment with chelating agents. When phosphate treatment is preferred over chelant treatment, the boiler water is conditioned to form a fluid sludge which can be removed by bottom blowdown. Formation of this sludge requires that alkalinity from caustic be present in the boiler water. If sufficient alkalinity is not maintained in the boiler water, a sticky precipitate will form and reduce heat transfer.

CHELANT TREATMENT:

A chelant is a compound which is capable of "grabbing onto" calcium, magnesium and iron. Chelant treatment of boiler water is attractive because the chelates of calcium and magnesium are soluble.
The undesirable scales of calcium carbonate and calcium sulfate are successfully eliminated by chelant treatment.
While the chelates of the hardness and iron contaminants are soluble, some chemistry precautions need to be mentioned. Phosphate will compete with the chelant for calcium, and if present in significant amounts, will result in undesirable calcium-phosphate deposits. Phosphate can enter the boiler water where city water makeup supplies phosphate. Both hydroxide alkalinity and silica compete with the chelant for magnesium. Depending on the concentration of all the boiler water chemistry, magnesium silicate deposits may result. Chelants should be fed to the feedwater downstream of any copper alloys, after the deaerator and before the boiler drum. The preferred feed location is down-stream of the boiler feedwater pump. A stainless steel injection quill is required.
Feed to the deaerator storage is not recommended since copper alloys in the boiler feed pump may be attacked. Proper feed of chelant will result in a chelant residual in the boiler water. The photo below shows the preferred feed locations for chelant feed and other requirements for adequate assurance of chelant control.
1. Feed chelant products continuously to boiler feedwater line, preferably after the economizer.
2. Use a 304 SS injection quill.
3. Use a 316 SS chemical feed line. (If not possible, ensure that 316 SS is used at least three feet prior to the injection quill).
4. Feed chelant only downstream from copper or copper alloys.
5. Feed catalyzed sulfite or a suitable oxygen scavenger to the storage section of the deaerating heater.
6. Assure that the feedwater mixes with boiler water before entering downcomer tubes.
7. Maintain feedwater pH >8.0


















Injection Quill

CONDENSATE RETURN SYSTEM:

When steam has performed its work in manufacturing processes, turbines, building heat, etc. it transfers heat and reverts back to a liquid phase called steam condensate. However, not all the energy used in producing steam is lost when condensate is formed. As most condensate return is still relatively hot (130OF to 225OF), it is very valuable as a source of feedwater. There is a significant fuel savings related to the heat required to raise the temperature of makeup water at (50OF to 60OF) to equal that of the return condensate, not to mention the additional cost in pretreating (softening) the makeup, as well as basic water cost itself.
When pure water H2O is used to produce steam, then its condensate is also pure H2O however, as we have learned the water we use to produce steam is not pure containing many dissolved minerals and gases. The heat and pressure of the boiler break down the alkalinity in the boiler water to form carbon dioxide gas CO2. Leaving the boiler with the steam it travels throughout the plant supply system. When the steam condenses, the carbon dioxide dissolves in it to form carbonic acid. This reaction is chemically expressed as:

H2O + CO2 = H2CO3

This acid depresses the condensates pH and causes corrosion to take place. This corrosion appears as grooving or gouging in the bottom of steam headers or condensate return lines. Most often it weakens pipe walls at threaded joints and the resultant metal loss can lead to large amounts of copper and/or iron being returned to the boiler to cause troublesome deposits. Oxygen, as in the boiler system, can cause localized attack in the form of pitting when present in the condensate system. This type of corrosion can generally cause equipment to fail more quickly than the generalized corrosion caused by carbonic acid attack due to it concentrating in a small area. Oxygen can infiltrate the system from open condensate receivers, poor deaeration or leaky siphons.
There are three main chemical programs to control corrosion in the condensate system, being neutralizing amines, filming amines and contamination neutralizing and filming amines.

NEUTRALIZING AMINES are high pH materials which neutralize the carbonic acid formed in condensate systems. By raising and controlling pH level in condensate from 7.5 to 9.0, neutralizing amines retard acid attack and greatly reduce the amount of corrosion products entering the boiler.
The three primary neutralizing amines in use today are:
1. Morpholine - a low distribution ratio product.
2. Diethyleminoethanal (DEAE) - a medium distribution ratio product.
3. Cyclohexylamine - a high distribution ratio product.
The distribution ratio is used to predict the amine concentration in the steam and condensate phases and impacts significantly regarding proper amine selection.
Distribution Ratio = Amine in Steam Phase / Amine in Condensate Phase

Neutralizing amines have low flashpoints and therefore can be fed directly to the feedwater or boiler water, or they can be fed directly into the steam header. The feed rate is based on the amount of alkalinity present in the feedwater. Neutralizing amines offer excellent protection against carbonic acid attack, but little protection against oxygen attack.

FILMING AMINES are various chemicals that lay down a vary thin protective barrier on the condensate piping protecting it against both oxygen and carbonic acid attack. The protective film barrier is not unlike the protection afforded an automobile by an application of car wax.
The protective film barrier is continuously being removed (a little at a time), requiring continuous feeding of the filming amine based on steam flow rather than feedwater alkalinity. Care must be taken to start this program slowly with an initial feedrate of one fifth that of the final feedrate to prevent the removal of old corrosion products from the system and their subsequent return to the boiler. Additionally, the filming amine should be fed using an injection quill to the steam header to insure proper vaporization and distribution throughout the steam system. The formation of gunk balls (Gunking) can occur due to overfeed, contaminants in the condensate or wide pH swings causing deposits to form in low flow areas like steam traps.

COMBINATION NEUTRALIZING AND FILMING AMINES are the combination of neutralizing and filming amines and are a successful alternative to protect against both carbonic acid attack and oxygen attack. As its name implies, it combines the elevated pH approach to neutralize carbonic acid in conjunction with the protective barrier film approach. The neutralizing amines, although they will elevate pH, main purpose is to provide better distribution of the filming amine throughout the condensate system which in turn helps to prevent gunking. As with filming amines they should be fed directly to the steam header utilizing an injection quill.

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