Monday, 20 May 2019


          The paper machine headbox is an equipment that supply low consistancy pulp (stock) uniformly into the forming section. The formation and uniformity if the final paper product depends on the dispersion of fibre and fillers. Machine headbox had major effect on paper qualities. There are different types of headboxes are present, all are not suitable for for all grades and types of paper and machine speed. Awell constructed headbox will give good quality paper. So the design headbox should be proper. The headbox is also called as "Stuffbox" or "Flowbox". 

Paper machine headbox types:

          In general the Headbox is catogarised into 3 major types, as Open type, Air padded type, and Hydraulic type.
         Hydraulic type of headbox is designed for high speed paper machines (speed above 350 m/min). Whereas open type open type headbox is designed for low speed paper machine. In Hydraulic and Air padded headedbox, the discharge velocity from the slice depends on the feeding pump. For this reason they are generally called as "Pressurised Headbox". The hydraulic headbox has no air pad, it is fully closed.
          Incase of air padded headbox pond level is maintained. Above the pond level it containes pressuried air. To maintain this air pressure we use headbox blowers. The stock level is known as Head, which is controlled by air pressure. The head determines the slice jet velocity or speed. These type of headboxes contains two or three "Holey rolls or rectifier rolls", and a "headbox shower".
          Multi layered headbox is available for making Tissue paper and light weight container board. Foe each layer it has different furnish compositions and delivary system.

Headbox jet velocity calculation:

          Jet velocity is the very important factor in the manufacturing of high quality paper. We have to maintain jet-to-wire velocity ratio; 0.97 to 1.03. The headbox jet velocity can be calculated from Bernoulli's equation:

Headbox Functions:

           The headbox serves many functions among them the following three functions are very important in the paper production process. If the headbox doesnot perform these three functions acceptbly, the quality of the paper produced will be greatly diminished.

1. Spread the low consistancy stock uniformly along the width of the wire.
2. Accelerate the stock and maintain constant velocity according to the paper machine operating speed.
3. Create control turbulance and suspend the pulp fibres throughout the out going slurry to eliminate fibre gathering.

Parts of Headbox:

The Headbox generally contains following parts:

1. Diffuser
2. Compressor line
3. Holly rolls
4. Rotating shower
5. Bottom lip
6. Top lip

Holey roll or Rectifier roll or evenor roll:

These rolls are genreally 2 to 3 present in headbox. These rolls are used for controlling both even outflow irregularities and to create turbulance to keep the fibre dispersed up to the slice opening. Normally hole diameter is 3 to 4 cm.

Rotating shower:

          This shower is used for continous headbox cleaning purpose and also consistancy maintenance.

Paper machine headbox slice:

          The paper machine headbox slice is a full width nozzle with a completely adjustable opening to give the desired rate of flow. The slice contains two lips; Top lip and Bottom lip. Among them bottom lip is adjustable; we can up or down or move sides also by hand operated or motor driven. On the otherhand top lip is fixed. The distance between the top lips are called Slice opening. The slice opening controls the stock jet velocity which is very importnat for the paper fromation.
The slice spindle contains a gearbox, connecting rod, Spindle, and hook which lifts bottom lip. 

Wednesday, 15 May 2019


          A Screw conveyor or Auger conveyor is a mechanism that uses a rotating helical screw, usually within a tube (Trough), to move liquid or grannular materials. The rotating part of this type of conveyor is called Auger.

          Screw conveyor in modern industry are often used horizontally or at a slight inclined as an efficient way to move semi-solid materials, including food waste, boiler ash, powder materials, agricultural material and many other. The first type of screw conveyor was the Archimede's screw, used since ancient times to pump irrigation water.

          They usually oncist a trough or tube containing either a spiral blade coiled around a shaft, driven at one end and held at the other end, or a "Shaftless spiral", driven at one end and free at other end. The rotational rate of shaft is directly proportional to the rate of material transfer.

          Screw conveyors can be operated with the flow of material inclined upward. As the angle of inclination increases, the capasity of a given unit rapidly decreases.

Types of screw conveyors:

1) Horizontal screw conveyor
2) Inclined screw conveyor
3) Shaft less screw conveyor
4) Vertical screw conveyor

Source take from Wikipedia

Monday, 6 May 2019


Mechanical Seals are the devices which arrests leakage of fluids when joined the parts or mechanisms together. Mechanical seals are available in different designs. We have to understand first how they function, it will help us to select the suitable for our application.
Different types of mechanical seals are mentioned below they are:
1. Conventional
2. Pusher
3. Non-Pusher
4. Blanced
5. Unbalanced
6. Cartridge 
7. Cortage

1. Pusher type:

Saturday, 4 May 2019



          Air knocker is a kind of process automation equipment, designed to eliminate problems occuring due to the deposition of powder inside a hopper. This equipment consists of a "Magnetic Piston". Due to the interaction between Magnetic Piston and Air pressure this equipment dislodges some force on hopper. 



Sunday, 28 April 2019


          The objective of treatment in a Base Exchange Softner is to convert hardness forming salts of Calcium and Magnesium to soluble Sodium salts. Due to the low solubility of Calcium and Magnesium Salts, they tend to precipitate and form scales when the temperature of water us increased.
          Sodium salts are highly soluble and hence do not form hard scales. The hard water, to be treated, flows through bed of bead type Polystyrene Cation Exchange resins in sodium form, which exchanges sodium ions with Calcium and Magnesium ions present in hard water.

There are two types of hardness present in water.
1. Temporary Hardness: This occurs due to presence of Carbonates and Bicarbonates of Calcium and Magnesium.
2. Permanent Hardness: This occurs due to presence of Sulfates, chlorides and nitrates of Calcium and Magnesium.

          The output capasity of the water softner is inversely proportional to the hardness present in the raw water. The resign has to be regenerated periodically with Sodium Chloride solution of 10-13% concentration.

The ion exchange reaction for the service runcan be presented as follows:

Ca++      +     2 NaR = CaR2       +        2 Na+
Mg++      +    2 NaR = MgR2      +           Na+
(hard water)   (resin in Na form)    (exhausted resin)    (soft water)
where R is the resin.

          From the above reaction, it will be seen that resign retains the Calcium and Magnesium and releases equivalent of sodium to the water leaving the Softner. After the Softner has produced specific quantity of soft water, the softner should be regenerated with Sodium Chloride. The reaction for the regeneration is given below:

CaR2 + 2NaCl       =     2 NaR     +          CaCl2
MgR2 + 2NaCl      =     2 NaR     +          MgCl2
(exhausted resin)  (common salt)   (regenerated Resin)  (waste to drain)
 Where R is the resin.

          It should be noted that the same Softner could produce less amount of Soft Water between two regenrations, with increase in raw water hardness. The quality of soft water may also get affected due to this increase/change in composition of raw water.

Sunday, 14 April 2019


          The major concern in industrial water treatment, where thw water used directly or indirectly in an industrial process, is to treat the water to be suitable for that particular application/process. The use of water in boiler for steam generation is an obvious industrial use. Depending on the process, varying degrees of purity of treated water are required. For example, a textile processing unit will require soft and clea water for process use; a chemical plant will require pure water for process not exceeding 1.0 mg/ltr of dissolved impurities or electronic components manufacturing unit require ultra pure water containing total dissolved impurities not exceeding 0.5 mg/ltr or less. So depending upon the requirement, various water treatment processes are adopted to ttreat the water, to make the water suitable for that particular application. The details of the process are as follows:

          Filtration is the process of passing a liquid containing suspended matter through a suitable porous material (filtering medium) to efficiently remove the suspended matter in the liquid. This is basically a physical treatment of water.
          Filtration is employed in the treatment of industrial water in order to remove or reduce suspended solids and turbidity. This is of special importance in boiler feed water as otherwise there will be formation of sludge and slit deposits. These will restrict flow, causes overheating and consequent failure of water wall tubes. Furthur, in combination with hardness, these sludge and slit deposits will add to the volume and has the insulating effect of scale deposits.

          1. Filtration is employed as a pre-treatment to softening or demineralising plants to protect the resins in them. It is also employed for treating potable water.
          2. The weakly basic anion resins exchanges only the strong acids such as Hydrochloric acid, Sulphuric acid and Nitric acid.

          There are basically two types of Filters - Gravity type, and Pressure type. For industrial applications the latter are preferred; they can be linked into the mains as they work under pressure and used in conjunction with other water treating equipment like softners, demineralisers without recourse to re-pumping. Also, Presure Filters are easier to install and operate, require less space and minimal civil work.

          Filter media commonly employed are graded and washed sand of effective size 0.35 mm to 0.5 mm resting on supporting underbed of crushed gravel and pebble of four varying sizes, with the coarsest size at the bottom of the bed. The sand depth is 500 mm and the underbed depth also 500 mm.

          The major components of a pressure filter are a steel pressure vessel with dished ends (normally vertical and cylindrical, though larger flows horizontal and cylindrical vessels are employed); internals comprising raw water distributor and filtered water collector-cum backwash water distributor; external pipe work and valves; filter media and instruments like pressure gauges, flow indicator etc.,

          Backwashing of the filter bed has to be carried out periodically (normally once in 24 hours, more frequently if the pressure drop across the bed exceeds 0.7 kg/cm and which indicates accumulation of dirt in the bed) with filtered water at a minimum head of 10 MWC. If air agitation facilitates are provided then the backwash rate can be reduced. The normal backwash time is 5-6 minutes and the scour time 2-3 minutes.

          NormallyFilters should not be fed with water carrying suspended matter and turbidity content of more than 30 to 50 NTU. Above these limits the water should be settled and clarified before Filtration. Also to increase the efficiency of Filtration and to ensure that even fine Suspensions are removed, the ususal practice is to dose Coagulant Chemicals like alum, ferrous sulfates or sodium aluminate at the inlet to the filter by means of a effluent. Activated carbon is used as a filtering Medium when oil/chlorine removal, etc, are required. A layer of processes Manganese Dioxide is incorporated in sand filters for iron removal. A layer of anthracite once the sand bed enhances the filtering capasity by providing in-depth filtration. When anthracite is used for filter can handle turbidity of upto 100 NTU.   

Saturday, 13 April 2019


          Water occurs in nature "pure" and what ever be the source always contains impurities either in solution or in suspension. The determination of these impurities makes analysis of water necessary and removal and control of these impurities make water treatment essential.

Water sources:
The various sources of water can be broadly classified as:
          a) Rain water
          b) Surface water (River, Streams, Ponds, Lakes and Reservoirs)
          c) Ground water (Springs, Shallow wells and Deep wells)
of the above, logically rain water is the purest but even this collects and dissolves atmospheric gasses and impurities in air. Further, once in contact with the earth's crust, the rain water will gradually dissolve various materials.

Various (Majour) impurities:
The major impurities of water can be classified in three main groups:
          1) Non-ionic and undissolved
          2) Ionic and Dissolved
          3) Gaseous

1) Non-ionic Impurities:  These are mainly, salt, mud, dirt and other suspended matter, micro-organisms, bactiria and other organic matter, oil and corrosion products. It goes without saying that drinking water and most industrial water supplied should be clear and organic-free.

2) Ionic and dissolved Impurities:  Any salt which dissolves in water disassociates into positively charged ions called "Cations" and negetively charged ions called "Anions". Since these permit the water to conduct electricity, these salts are called electrolytes.
          Some of the most common Cations in water are:
      Calcium, Magnesium, Sodium and Iron, and rarely Ammonium, Potassium and Manganese. These cations are associated with Anions like Bicarbonates, Carbonates, Hydroxides (the sum of which is termed as Alkalinity), Sulfates and Chlorides. Presence of Nitrites and Phosphates is normally not very common. In the water treatment field, the preferred method of expression of these dissolved impurities is in terms of Equivalent Calcium Carbonate, abbrevated to as "CaCO3". This is because Calcium Carbonate is a good common denominator as it has a molecular weight of 100, which facilitates calculations.
          Moreover, in this form of analysis, the sum of Cations or total Cation always equals the total Anions. Quantitatively, these are expressed in parts per million or milligram/ltr. One part per million equals one ten thousandth of one percent (0.0001%). One part per million means one part in a million parts, for example, one liter in a million liters of water or one Kg in a million Kgs of water.
          Of all the dissolved impurities, hardness is perhaps the most troublesome. Hardness is due to compounds of Calcium and Magnesium. On heating water caontaining these salts, Carbon Dioxide is released from solution and the Bicarbonates are converted into Carbonates which are insoluble and form scales and deposites. Other salts of Calcium and Magnesium like Sulfates and Chlorides have lower solubility than Sodium salts and participated out at high temperatures. Bicarbonates of Calcium and Magnesium are known as the "Alkaline hardness" or "Temporary hardness" and chlorides, sulfates, nitrates etc., of Calcium and Magnesium are known as "Neutral" or "Permanent hardness". Sodium salts are highly soluble but can be corrosive if present in large quantities such as Sodium Chloride or Sodium Bicarbonate.
          Dissolved Silica is another troublesome impurity, especially in water fed to Boilers of very high temperatures and pressures. Even in lower pressure boilers, it could form a very hard type of scale by acting as a binding agent.
          The natural water contains solid, liquid and gaseous impurities and therefore, this water cannot be used for the generation od steam in the boilers. The impurities present in the water should be removed before it'suse in steam generation. The necessity for reducing the corrosive nature & quantity of dissolved and suspended solids in feed water has become increasingly important with the advent of high pressure, critical & supercritical boilers.

Impurities in water:
The impurities present in the feed water are classified as given below -

-- Undissolved and suspended solid materials.
-- Dissolved salts and minerals.
-- Dissolved gases.
-- Other materials (as Oil, Acid) either in mixed or unmixed forms.

A. Undissolved and suspended materials: Turbidity and sediments:
          Turbidity in the water is suspended insoluble matter including coarse particles (mud, sediment, sand etc.,) that settle rapidly on standing. Amounts range from almost zero in most ground waters and 60,000 ppm in muddy and turbulent river water. The turbidity of feed water should not exceed 5 ppm. These materials can be removed by settling, coagulation and filtration. Their presence is undesirable because heating or evaporation produces hard stony scale deposits on the heating surface and clog the fluid system. Both are objectionable as they cause damage to the boiler system.

B. Dissolved salts and minerals:

a) Calcium and Magnesium salts: The calcium and Magnesium salts present in the water in the form of carbonates, bicarbonates, sulfates and chlorides. The presence of these salts is recognized by the hardness of water (Hardness of water is tested by soap test). The hardness of water is classified as temporary and permanent hardness. The temporary hardness is caused by the bicarbonates of calcium and magnesium and can be removed by boiling. The boiling converts the soluble bicarbonates into less soluble carbonates which can be removed by simple blow down method. The permanent hardness of the water is caused by the presence of chlorides, sulfates and nitraes of calcium and magnesium and they cannot be removed just by boiling because they form a hard scale on heating surfaces.
          A standard amount of measurement of hardness is taken as being the amount of Calcium Carbonate (CaCO3) in th water and is referred to in part per million (ppm) or grains per gallon (grains/gallon*17.1=ppm).

b) Sodium and Potassium salts:  These are extremly soluble in water and do not deposit unless highly concentrated. Their presence is troublesome as they are alkaline in nature and accelerated the corrosion.

c) Chlorides:  Majority of the chlorides cause increased corrosive action of water.

d) Iron:  Most common soluble iron in water is ferrous bicarbonate. The water cantaining ferrous bicarbonate deposits become yellowish and reddish sediments of ferric hydroxide if exposed to air. Majority of ground surface water contains less than 5 ppm but even 0.3 ppm can create trouble in feed water system by soft scale formation and accelerating the corrosion.

e) Manganese:  It also occurs in similar form and it is also equally troublesome.

f) Silica:  Most natural water contains silica from 1 to 100 ppm. Its presence is highly objectionable as it forms very hard scale in Boilers and forms insoluble deposits in turbine blades. In modern high pressure boilers its presence is reduced as low as 10-50 ppb.

g) Microbiological Growth:  Various growth occur in surface water (lake & river). The micro-organisms include diatoms, molds, bacterial slimes, algae, manganese & sulphate reducing bacteria and many others. These can cause coating on Heat Exchanger and clog the flow passages and reduce the heat transfer rates.

h) Colour:  Surface waters from swampy areas become highly colored due to decaying vegetation. Colour of feed water is objectionable as it causes foaming in Boilers and may interfere with treatment processes. It is generally removed by chlorination and absorption by activated carbon.

C. Dissolved Gases:

a) Oxygen:  It presents in surface water in dissolved form with variable percentage depending upon the water temperature and other solid contents in water. Its presence is highly objectionable as it corrosive to iron, zinc, brass and other minerals. It causes corrosion and pitting of water lines, boiler tubes. Its effect is furthur accelerated at high temperatures.

b) Carbon Dioxide:  The river water contains 50 ppm and well water contains 2 to 50 ppm of C02. It also causes the corrosion of stream, water and condensate lines, It also helps to accelerate the corrosive action of oxygen.
          wThe other gases are H2S, CH4, N2, and many others but their percentages are negligible, therefore, their effects are not discussed here.

D. Other minerals:
a) Free Mineral Acid:   Usually present as Sulphuric or hydrochloric acid and causes corrosion. The presence is reduced by neutralization with alkalis.

b) Oil:  Generally, the lubricating oil is carried with steam into the condenser and through the feed system to the Boiler. It causes sludge, scale and foaming in Boilers. It is generally removed by strainers and baffle seperators.
          The effects of all the impurities present in the water are the scale formation on the different parts of the boiler system and corrosion. The scale formation reduces the heat transfer rates and clog the flow passage and endager the life of the equipments by increasing the temperature above safe limit. The corrosion phenomenon reduces the life of the plant rapidity. Therefore, it is absolutely necessary to reduce the impurities below a safe limit for the proper working of the power plant.

C. Dissolved Gases:
The atmosphereic gases found in naturally occuring waters, only two Carbon Dioxide and Oxygen, are the main causes of many corrosion related problems.


          Water occurs in nature "pure" and what ever be the source always contains impurities either in solution or in suspension. The determination of these impurities makes analysis of water necessary and removal and control of these impurities make water treatment essential.

Water sources:
The various sources of water can be broadly classified as:
          a) Rain water
          b) Surface water (River, Streams, Ponds, Lakes and Reservoirs)
          c) Ground water (Springs, Shallow wells and Deep wells)
of the above, logically rain water is the purest but even this collects and dissolves atmospheric gasses and impurities in air. Further, once in contact with the earth's crust, the rain water will gradually dissolve various materials.

Various (Majour) impurities:
The major impurities of water can be classified in three main groups:
          1) Non-ionic and undissolved
          2) Ionic and Dissolved
          3) Gaseous

          In this article we discusses briefly about the water treatment processes indicating the various impurities present in the water and the different types of treatment processes such as 'Filtration' and 'Demineralization', for treating the water for eliminating the suspended and dissolved impurities.

Table of contents

3) Water softnening process
4) Standard Operation Procedure (SOP) of Water treatment plant (for example purpose)

Saturday, 6 April 2019

Ribbon Blender: Construction, Operation, and Applications

          RIBBON BLENDER (or) mixer machine is widely used for dry powder, Grannules, Low-viscosity paste and liquid in chemicals, food and cosmetics industries. It is particularly appropriate for combining solids and solids with liquids, Approximately two third of the volume of the container of ribbon blender is stuffed to make sure proper mixing.
           The Ribbon Blender can be used in either batch or continous flow form to achieve even and homogeneous blending.

Construction & Operation:
          Ribbon blender consists of a "U"-shaped trough containing a double helical ribbon mixer that rotates inside. The blender's shaft is positioned within the centre of the through and has welded spokes on that helical ribbons (also referred as spirals) are welded. Since the agitator consists of a group of inner and outer hical ribbons, it is saaid as a "double" helical ribbon agitator. The gap between the ribbon's outer edge and the interwalls of the vessel ranges from 4 to 5 mm depending upon application.

          Generally the ribbon blender is powered by a drive system consists of motor, coupling, and gearbox. For blending 500-1000 kg of product a 10 HP to 15 HP  motor is used.
          The agitator shaft exits the blender container at either end through the end plates secured or welded to the container. The area where the shaft exists the container is given a sealing arrangement to make sure that material doesn't travel from the container to the outside and vice-versa.
          The charging of material is generally done through top cover, the cover also containes cleaning and maintenance access. The material is to be blended are loaded into the blender upto 40 to 70 % of the total volume of container. This is generally up to the level of the outer ribbon;s tip. Depending upon the application the agitator is designed to operate at pheripheral speed (also called as tip speed) approx 100 mtr/min.
          During blending, the outer ribbons move the material from the ends to the centre while the inner ribbons move the material from centre to ends. Radial movement is achieved because of the rotational motion of the ribbons. The difference in the pheripheral speeds of the outer and inner ribbons results in axial movement of the material along the axis of the blender. As a result of cobining motions of these homogenious blending is achieved in short time. The efficiency of the blender depends on particle size, density and quantity.
          After blending, the material is discharged form discharge valve located at the bottom of the through. The discharge can be fitted with any kind of valve like slider gate, butter fly depending upon the material. The operation of valve can be done by manual or automatic.
          The motion of the ribbons near the walls can result in "pinch" points, or regions of higher shear and compression, which may damage fragile material. In some cases this can leads to friction and heat generation resulting in product degredation.
          An alternate design to the ribbon blender is paddle agitator, which can handle fragile material. The paddle agitator is composed of both forward and reverse paddles in place of the ribbons. The paddles are positioned to  ove the material in opposing lateral direction as well as in a radial direction. The ribbon design is appropriate for low and medium duty applications, hile paddle design is suitable for heavy duty applications. In some cases we can see hybrid-design like paddle and ribbon agitator.

Name plate details:

Blending Capasity1 m3 (300 kg) or 1.8 m3 (500) kg
Motor Capasity7.5 KW (10 HP) or 11 KW
Speed rates20 RPM
Weight1.5 Ton or 2 Ton
MakeEx:Alpha Factory Automation Ltd

1) Blending large amount of dry solids.
2) Dry blending of capsule formulation.
3) Cooling, drying, heating of materials.
4) Blending of chemicals.

Materials commonly blended are:
Plastic resigns
Epoxy resigns
Face powders
Instant drink blends
Talcum powders
Laundry detergents

Saturday, 16 February 2019


          A chiller is a machine, its function is to remove heat from a liquid or from one location (Generally process equipment or product) to another place (Genarlly the air outside the manufacturing facility) through a Vapour-compression cycle or absorption cycle. To transfer the heat to and fro from the chiller we commonly use water or water/glycol solution. This liquid is recirculated through a heat exchanger to cool equipment, or another process stream (such as air or process water). As a necessary by product, refrigiration process creates waste heat that must be exhausted to ambience, or for greater efficiency, recovered for heating purposes.

          Chilled water is used to coll and dehumidify air in midum to large commercial and industrial facilities. Water chillers are water cooled, air-cooled, or evaporatively cooled. Water cooled system can be provide efficiency and doesnt harm to the environment when compared to air-cooled systems.

          Industrial water chillers are used to cool products and machinary, like injection molding, tool and die cutting, food and beverage, chemicals, lasers etc.,

          Regardless of industry and process, we have to make sure that we have sufficient cooling system which gives productivity and cost saving.

How does a Chiller Work?
          In most process cooling applications, a pumping system circulates cool water or a water/glycol solution from the chiller to the process. This cool fluid absorbs (removes) heat from the process and this warm fluid returns to the chiller. By this process the heat from the process transfers to the chiller.

          Chiller contains a chemical compound called a refrigerant. There are many types of refrigerent and their applications depending on the process temperatures we required. All refrigerents works on the same basic principle that compression and phase change of the refrigerent from a liquid to a gas (vapour) and back to liquid. This process of heating and cooling the refrigerent and changing it states (liquid-vapour-liquid) is called refrigeration cycle.

          The refrigeration cycle starts with a low-pressure liquid/gas mix entering the evaporator. In the evaporator, heat from the process water or water/glycol solution is transfered to the refrigerent, which changes it from a lo-pressure liquid to a low-pressure gas (vapour). The low-pressure gas enters the compressor where it is compressed to high-pressure gas. The high-pressure gas enters the condensor where ambient air or condenser water removes heat to cool it to a high pressure liquid. The high-pressure liquid travels to the expansion valve, the expansion valve controls the amount of liquid refrigerent enters the evaporator, thereby beginning the refrigeration cycle again.

          There are two types of condensers used chillers; they are air-cooled and water -cooled. An air-cooled condenser uses ambient air to cool and condenstae the hot refrigerent vapour to a liquid. It can be located inside the chiller or outside the chiller, but its ultimate function is to remove the heat from chiller to the air. In water cooled condenser, water which is circulated from the cooling tower cools and condenses the refrigerent.

Best chiller for your process and selection:

          Chillers are ranges in many sizes and design. Chiller selection depends upon total life cycle cost, the power source, evoporator capasity and material, condenser capasity and material, ambient temperature, coolant, discharge temperature of fluid, and COP. Based on these factors chillers are available as small, portable units to large central chillers.       

Image Courtesy: The

@2017 All Rights Reserved. Designed by WWW.SMARTWAY4STUDY.COM !!!! Sitemap !!!! Blogger Templates