Short: Normally, the evaporation ratio depends upon number of parameters;

• Calorific value of the fuel 

• Efficiency of the system 

• Types of boiler

Details:

As a thumb rule evaporation for boilers operating with the use of different fuels is as below:

• Biomass fired boilers : 2.0 to 3.0 

• Coal fired boilers        : 4.0 to 5.5

• Oil fired boilers          : 13.5 to 14.5

• Gas fired boilers       : 11.0 to 13.0 

Thus the evaporation ration should be anywhere from 13.5 to 14.5 as this is an HSD fired boiler. To start with one should check the stack (flue gas) temperature. Recommended stack temperature is between (175 to 225)0C. If the temperature is above then it is a signal that the boiler needs maintenance (descaling/soot blowing). This is one of main reasons for low evaporation ratios. It is a good practice to keep a log book in the boiler house to record different parameters of the boiler including stack temperature which help in providing early signals of inefficiencies in the boiler operation.

Besides this reason if equipment is available it is recommended to check the air fuel ratio/combustion parameters, one could also check the condition of the nozzles of the burner, quality of fuel etc. If waste heat is available in different processes one could preheat the feed water. Also a condensate recovery unit could be installed to improve the evaporation ratio.

Evaporation ratio means kilogram of steam generated per kilogram of fuel consumption.

For example, 

• 1 Kg of Rice husk can generate 4 kg of steam

• 1 kg of coal can generate 6 kg of steam 

• 1 kg of HSD can generate 13 kg of steam 

Other parameters to observe;

• Incomplete combustion 

• Excess air

• Combustion air preheat

• Radiation heat loss

There could be many reasons for this some of which are listed below:

• Additional load on the system (insufficient steam available at digester)

• Improper pipe sizing causing pressure drop.

• Improper selection of Steam traps in the distribution system.

• Quality of steam.

Please check out steam consumption of digester. Normally, lower cooking pressure on stem consumption results less steam required to heat the digester and takes more time. Temperature plays important role in cooking so study heat lost by radiation. 

When you say black smoke it is a sign of incomplete combustion. There could be several reason of black smoke coming out from boiler. 

• Insufficient oxygen supply to support combustion (Excess Air)

• Excess feeding of fuel 

Preventive Measures:

• Maintain proper air fuel ratio by installing air fuel sensor

• Install Bag filter (precipitator) to control black smoke

Bag filter are air pollution controlling industrial equipment used prominently in a steam boiler house assembly. 

Excess Air

The quantity of air in excess of the theoretical minimum air required for complete combustion of the solid and liquid fuels is excess air. Free oxygen in the products of combustion is an indication of the excess air. Usually the CO2 recorder provides the indicating of excess air. For a fuel containing only carbon, the theoretically correct combustion will yield in products of combustion only CO2  and N2. 

Excess air is estimated by the equation            = 100 *(21-%Oxygen)

                                                                                     (% Oxygen)

Usually CO2 % varies from 10 –12% by volume in boilers with natural draught and 10-15 % by volume in boiler with artificial draught. The boiler efficiency is maximum within small excess air. For higher excess air, higher is the heat loss in the exhaust. 

For natural gas boilers, 10% excess air corresponds to 2.2% oxygen in the flue gas. For coal-fired boilers, 20% excess air corresponds to 4% oxygen. The recommended excess air for various fuels is shown below: 

This question is very subjective and dependent on the availability/ cost of fuel and technology. Per say burning of gases (gas fired boilers) would be more environment friendly as combustion is more efficient but this might not suit your process requirements.

Before purchasing an industrial boiler you need to know your operational specification, how much steam you need or required per hour from the boiler. Along with that you should what boiler will suit you according to your nature of industry and what fuel is easily available within your locality. 

Additionally, make sure you are familiar with its thermal efficiency, temperature, pressure and heat output capacity. 

There could be several reason of black smoke coming out from boiler. 

• Insufficient oxygen supply to support combustion (Excess Air)

• Excess feeding of fuel 

Preventive Measures:

• Maintain proper air fuel ratio by installing air fuel sensor

• Install Bag filter (precipitator) to control black smoke

• Excess Air

• The quantity of air in excess of the theoretical minimum air required for complete combustion of the solid and liquid fuels is excess air. Free oxygen in the products of combustion is an indication of the excess air. Usually the CO2 recorder provides the indicating of excess air. For a fuel containing only carbon, the theoretically correct combustion will yield in products of combustion only CO2 and N2. 

Excess air is estimated by the equation       = 100 *(21-%Oxygen)

                                                                              (% Oxygen)

Usually CO2 % varies from 10 –12% by volume in boilers with natural draught and 10-15 % by volume in boiler with artificial draught. The boiler efficiency is maximum within small excess air. For higher excess air, higher is the heat loss in the exhaust. 

• For natural gas boilers, 10% excess air corresponds to 2.2% oxygen in the flue gas. For coal-fired boilers, 20% excess air corresponds to 4% oxygen. The recommended excess air for various fuels is shown below: 

1. I am not being able to generate the required pressure within the boiler.

• Short:

In such case it is important to identify the root cause as soon as boiler in order to protect boiler from getting damage or blast. 

Due to several reason boiler could not able to generate pressure.

1. water escaping somewhere in the system

2. failure of the expansion valve and resulting damage to the pressure relief valve

Reasons for the mentioned problem could be:

• The amount of steam sent out exceeds the rated evaporation;

• Leakage of pipeline valves;

• Problems with fuel supply lead to strong and weak combustion;

• The boiler's heat transfer has changed due to serious Scaling;

• The boiler feed water temperature is too low.

• Leakage of check valve, safety valve, pressure relief valve, drain valve, etc.;

One could look at the following measures to mitigate the problem.

• If the boiler supply steam cannot meet the production requirements, it is recommended to purchase another boiler.

• You need to stop the furnace to check (internal, arch wall, fire cement) whether there is any leakage,

• Replace the corresponding parts in time to prevent the leakage from expanding.

• Choose the right fuel. Ensure sufficient fuel supply. It is recommended to reserve some spare fuel.

• Ensure the quality of boiler feed water, and perform boiler blowdown regularly. Clean the inside of the drum regularly and ensure it is clean.

• Install an economizer to increase the boiler feed water temperature.

• Regularly check the valves of the boiler system. Ensure normal use.

Above all, regular maintenance can effectively reduce boiler malfunctions, especially for industrial steam boilers.

• Details: Let's take a closer look at these two situation and what actions one can take to solve this problem.

1. Pressure loss due to water leakage (check all leakage in the pipeline , joints or fixtures)

2. Detecting leaks

3. loosing pressure due to boiler fault (after all the above check if you could not find the fault then now you can focus on boiler itself) 

Make sure you consult qualified boiler engineer 

2. I want to purchase boiler for my plant but I have no idea what capacity should I order, Could you please explain?

• Before purchasing an industrial boiler you need to know your operational specification, how much steam you need or required per hour from the boiler. Along with that you shouldwhat boiler will suit you according to your nature of industry and what fuel is easily available within your locality. 

Additionally, make sure you are familiar with its thermal efficiency, temperature, pressure and heat output capacity. 

Note: Oversize boiler are expensive to run, while undersized will not be able to meet your requirements. Never make a rushed decision to purchase an industrial boiler. These equipment can be costly and dangerous if not used properly.

Some basic factors that influence boiler selection can be listed as below:

• Quality of fuel

• Type of fuel

• Availability of water and its quality

• Load Factor

• Location of the Process plant

• Operating pressure

• Power required

• Cost of maintenance and operation

• Cost of Erection & Installation.

• Availability of floor space.

For this you need an equipment to be able to measure consumption of fuel, steam/feed water and time.

Step 1: would be to note opening balance/ flow meter reading of fuel, opening balance/reading of steam/feed water flow meter and time.

Step 2. Allow operation of boiler as normal for a period of a minimum 1 hour and if possible 3-4 hours (longer the better). Make sure that during this period valves of makeup water/condensate return are in closed position and there is no addition of fuel.

Step 3. Record the consumption of stem/feed water and fuel for the period.

Evaporation ratio would be calculated by the formula below:

Evaporation Ratio (fuel to steam ratio) =    Consumption of Steam/Feed water   x 100

                                                        Consumption of Fuel 

As a thumb rule evaporation for boilers operating with the use of different fuels is as below:

• Biomass fired boilers : 2.0 to 3.0 

• Coal fired boilers        : 4.0 to 5.5

• Oil fired boilers          : 13.5 to 14.5

• Gas fired boilers       : 11.0 to 13.0 

• Steam fuel ration or Evaporation ratio means kilogram of steam generated per kilogram of fuel consumption.

For example, 

• 1 Kg of Rice husk can generate 4 kg of steam

• 1 kg of coal can generate 6 kg of steam 

• 1 kg of HSD can generate 13 kg of steam 

There are two methods of calculating boiler efficiency;

• Direct Method (Easy to calculate but not very accurate)

• Indirect Method (Difficult (lengthy) to calculate and recommended to carry out an audit)

The formula for calculating boiler efficiency by the Direct Method is as below:

Efficiency =    Heat addition to Steam x 100

Gross Heat in Fuel 

OR

  = Steam flow rate x (Steam enthalpy – feed water enthalpy) x 100

            Fuel firing rate x Gross calorific value of fuel

Calorific value of some fuels

Calculate thermal efficiency is possible, internal benchmarking of the fuel consumption, age of the boiler, heat loss in the pipe line, condensate heat recovery. 

Generally, a boiler is supposed to be in operation for 10 to 12 years, but it can exceed with a little maintenance as well as decrease depending on the use. However, when your boiler experiences enough repairing, stop right there. It’s time to get a new system that will save you enough money as well as reduces the energy cost.

Some points to be noted when making a decision to replace the existing boiler:

• Existing plant is old and inefficient 

• Boiler is not capable of firing cheaper substitution fuel

• Boiler is over/under sized for duty

• Boiler design is not ideal for present loading conditions.

Take help from boiler expert.

Nearby load, so that there is minimum pressure drop. If steam pipeline have to travel a longer distance, pressure decreases so again more fuel is burn to meet the required pressure. 

The compressor should stop once the tank pressure reaches set cut-off pressure. 

If the air pressure in the tank does not reach the set cut out pressure level, then the air compressor can't shut off as the pressure never reaches the cut out pressure level.  

Other reason could be 

1. Internal gasket leakage 

2. pressure release valve failure

3. Pressure switch valve failure

Location of the compressor should be nearby the plant that would help to maintain the air pressure. 

1. Previously the compressor is working and sufficient but now it’s’ not sufficient for the same system why?

• Compressed air system is one of the most widely used forms if energy from small auto shops to large cement and textile industry. 

The main reason for compressor to be insufficiency for same system is the loss of heat generated from the increased temperature of pressurized air and from friction causes by the system many moving parts. 

When it comes to air compressor efficiency, it is important to examine the entire system, which include not only air compressor but all the supply lines, leakages, air storage tanks, air dryers, filters, receivers and after coolers. 

Other reason could be quality of air intake; i.e 

1. Its temperature- The temperature of the air intake determines the density of the air. Cool aor requires less energy to compress.

2. Humidity – Moisture can be harmful to an air compressor system. Since it accumulates inside the system causing components to rust. This may leads to wear and tear as well as leaks and reduce storage capacity. Dry air is less likely to damage air compressor system and tools performing work at the point of use. 

3. Composition- Clean air intake ensures that compressed air can move more smoothly through the system, Dirty air contains contaminants that accumulates and again cause wear and tear which would reduce the storage capacity. 

2. Plate reading is different than the real consumption why?

• It is certainly possible for a compressor to consume more power than rated. When load on compressor or when pressure is increased, it draws more current and it consume more than the rated capacity. 

Normally, the designer design the machine for specific condition and environment. If the machine is operated out of the design range, the machine gets heat up and consume more power. 

The best possible solution is to install voltage stabilizer.Low voltages sometimes can be due to overloading on the network, loose connection or too small a conductor wire carrying power. 

Normally, submersible pump will last around 15 years. However, it will only last 5 to 6 years if water has low sediment. Sediments in water reduced the life of the motor in pump.And for jet pumps which are above ground its life expectancy is about 10 years. 

Also, There are several factors in which the life of motor depends on pump;

• Pump Duty cycle: Pumps that are frequently in use will have a much shorter lifespan than those that aren’t used often. 

• Water sediments: The sediments in the water plays a part in how long a water pump will last. Water sediments acts as an abrasive that wears down the bearings and moving parts within pump.

• Motor quality and size: The more horsepower your engine has, the larger it will typically last. 

Higher quality bearings within a motor also increase the lifespan of a well pump. 

• Quality of Installation: For a well pump with a long lifespan it is important that you hire the right company to do the installation. 

Answer to the second question is yes, it is cost effective. Best efficient pump will lower the energy consumption that would reduce total electricity bill.  Now coming to selection part before selecting pump one must know about four major things;

1. The total head or pressure against which it must operate.

2. Flow rate of pump

3. The suction lift

4. And, fluid characteristics i.e. presence of sediments, temperature, presence of dirt, sand, twigs etc.)

It depends on size of the pumping station; larger the capacity more energy savings options. 

Energy efficiency options can be from energy consumption to energy generations.

• Consumption side – No. of Transformer/ standby transformer/Feeder/loading capacity/ approved demand

• Generation side – Diesel Generator/ UPL(unit per litre)// loading/

• TOD – Time of Day- Operation hour / storage timing in off peak hour

• Automatic Power Factor Correction (APFC)

• Motor- Energy Efficient Motor/Size- oversized, undersized 

• Pump –Energy Efficient Pump/ Size- oversized, undersized

• Installation of VSD

• Cooling tower pump- fan 

• Lighting System 

• Air compressor – VFD Compressor 

• Design- 

• Minimize throttling

• Adequate Net Positive suction head (NPSH)

Well, it depends on lot of parameters such as depth, lifting height By standard, specific energy consumption ranges from 0.5 kWh per m3 to 0.9 kWh per m3.

A ton, as used in the HVAC field, is a term that describes how much heat the AC unit can remove from a home in one hour. 

Here ton doesn’t mean the weight it's the measurement for heat is the British thermal unit (BTU). One ton of air conditioning can remove 12,000 BTUs of air per hour. A four ton unit can move 48, 000 BTUs and so on. Therefore, the more tonnage an AC unit is rated at, the more air it can cool.

The cooling effect of refrigeration systems is generally quantified in tons of refrigeration. 

1 Ton of Refrigeration (TR) = 3023 kcal/hr = 3.51 kW thermal = 12000 Btu/hr 

The commonly used figures of merit for comparison of refrigeration systems are Coefficient of Performance (COP), Energy Efficiency Ratio (EER), Specific Power Consumption (kW/TR) these are defined as follows: 

If both refrigeration effect and the work done by the compressor (or the input power) are taken in the same units (TR or kcal/hr or kW or Btu/hr), the ratio is 

COP = Refrigeration Effect

          Work done

If the refrigeration effect is quantified in Btu/hr and the work done is in Watts, the ratio is 

EER = Refrigeration Effect (Btu/hr)

Work done (Watts)

Higher COP or EER indicates better efficiency. 

The other commonly used and easily understood figure of merit is 

Specific Power Consumption = Power Consumption (kW)

                                                      Refrigeration effect (TR)

A lower value of Specific Power Consumption implies that the system has better efficiency.

Well, it depends what temperature difference is required for your plant. For example, if you have four chiller in the plant we recommend you to shut down 1st chiller and look at the product if the quality is best you can shut down the second one and so on. We also recommend you to make the use of cooling tower instead of chiller during winter season. Well it also depends on your requirements. 

Additionally, chillers are equipped with sensors to be able to conditions of the conditioned space. Thus, if i senses that there the temperature and humidity conditions are being maintained in the conditioned space the chiller should stop automatically. Yes if you think that the ambient conditions are such that by use of the cooling tower only you could maintain the conditions within the conditioned space you could switch off the chillers. But please make sure the conditioned space is monitored carefully so as not to damage materials/machines stored in the conditioned space.