Recent questions tagged utilities

Description : Does anyone remember when meter readers regularly came into your home to check your utility usage?

Last Answer : The utility company replaced electric meters with wireless broadcasting meters a couple years ago, with low-power radios. He drives down the street once a month and has its transceiver query my meter, Something like this

Description : What are electricity and water bills like in Chula Vista, CA?

Last Answer : If you bought the house the realtors often have historical info about utility bills that previous residents paid. Utility companies might give you the same info if they can verify you are the new ... you might spend a bit on air-conditiioning depending on how close to ocean breezes you are.

Description : Which is the best Mac data recovery software?

Last Answer : I wouldn’t trust any of them. Have you already lost data? If you have shut your computer down. Every second you are writing over files you might want to recover. Use a different computer while you figure out what to do.

Description : A refrigerator is working on reversed carnot cycle between temperature of 30°C to –10°C with capacity of 10 tonnes. Calculate. (i) The COP (ii) Define ton of refrigeration (iii) Give the industrial application of refrigeration

Last Answer : (ii) Ton of refrigeration: It is defined as the quantity of heat required to be removed from 1Ton water at 0oC to get ice at 0oC in one day. (iii) Industrial applications of refrigeration ... food stuff such as meat, fruit, fruit juice, vegetables etc. 5. Ice cooling of concrete for dam.

Description : Explain the construction and working of induced draft cooling tower with neat sketch.

Last Answer : Induced draft cooling tower :  Diagram: Construction and working: Cooling towers are employed to cool utility cooling water by direct contact with air. The parts of a cooling tower are ... top pulls the hot air through the fills and cooled water gets collected in the cold water basin.

Description : State the factors to be considered while selecting refrigerants. 

Last Answer : Selection criteria for refrigerant : 1. Working pressure range and pressure ratio. The pressure required to be maintained in the evaporator and condenser should be low enough to reduce the material ... . It should have moderate density in liquid form, a relatively high density in gaseous form.

Description : Describe with a neat diagram the working of a simple vapour compression refrigeration system. Represent the cycle on P–V and T–S diagram. 

Last Answer : Vapour compression refrigeration cycle: The vapor-compression uses a circulating liquid refrigerant as the medium which absorbs and removes heat from the space to be cooled and subsequently rejects that heat elsewhere. Figure shows ... the compressor. P-V Diagram T-S diagram: 

Description : Give the advantages of multistage compression.

Last Answer : 1.Saving in work is obtained 2.There is little chance of lubrication trouble as the maximum temperature is reduced. 3.it improves the volumetric efficiency. 4.the leakage loss is reduced ... 5. it provide more uniform torque and thus smaller size flywheel is required. 6.lighrter cylinders.

Description : Explain the method for obtaining instrument air in industry.

Last Answer : Instrument air: Air is passed through a filter to remove suspended impurities. The filtered air is supplied to the compressor. Discharge from the compressor will be at a pressure of 100 to 150 ... pressure regulator is sometimes added to provide a constant reduced pressure in the supply line.

Description : Explain boiler act with respect to (i) Duties of chief inspector (ii) Registration of boiler.

Last Answer : Boiler act: Duties of chief inspector: Maintain records of registered boilers. Examine boiler inspection reports produced by inspectors. Decide whether to issue the certificate for the operation of ... shall examine the boiler and find maximum pressure at which the boiler may be operated.

Description : Explain working of water level indicator with neat sketch.

Last Answer : Water level indicator: Working: Its function to indicate water level in boiler. usually two water level indicator are fitted to in front of boiler. WLI shows the water level in in the boiler drum ... goes below a fixed mark , so that corrosive action may be taken in time to avoid accident. 

Description : List the methods for scale and sludge removal.

Last Answer : Methods of scale and sludge removal: With the help of scrapper, knife ,blades or piece of wood or by wire brushing, if the scale is loosely adhering. By giving thermal shocks. By ... suddenly cooling with cold water. By dissolving them in some chemicals. By frequent blow-down operation.

Description : Explain the working of cyclone separator with labelled diagram.

Last Answer : Cyclone separator: Working: Cyclone separators work much like a centrifuge, but with a continuous feed of dirty air. In a cyclone separator, dirty flue gas is fed into a chamber. The inside ... at the bottom of the container. The cleaned flue gas escapes out the top of the chamber.

Description : Differentiate between water tube boiler and fire tube boiler

Last Answer : Fire tube boiler Water tube boiler In Fire-tube boilers hot flue gases pass through tubes and water surrounds them. In Water-tube boilers water passes through tubes and hot flue gasses ... them. In Water-tube boilers water passes through tubes and hot flue gasses surround them.

Description : “Rate of softening of water in Ion Exchange method is high,” Give reason.

Last Answer : Rate of softening of water in ion exchange method is high because, cation exchange beds and anions exchange beds are used this process, which remove all the hardness causing substances. It also removes alkali metals. This process is useful for acidic as well as alkaline water. 

Description : Draw the diagram for zeolite process used for the softening of boiler feed water.

Last Answer : Zeolite process:

Description : Name any four psychometric process and represent them on psychometric chart. 

Last Answer : Psychrometric process and their representation on psychrometric chart: 1. Sensible heating or cooling 2.Cooling and dehumidification: 3.Heating and humidification 4.Adiabatic mixing of two streams 5. Chemical Dehumidification  6.Adiabatic evaporative cooling

Description : Explain the working of super heater

Last Answer : Working of Super heater: Superheater header mounted against the tube sheet in the smoke box.The steam is then passed through a number of superheater elements-long pipes which are placed inside special, ... into a separate compartment of the super heater header and then to the cylinders as normal. 

Description : Classify boilers according to various factors. 

Last Answer : Classifications of boilers 1.Use a. stationary b. mobile 2. Tube contents a. fire tube boiler b. water tube boiler 3. Tube shape and position a. Tube shape (Form) -i. Straight ii. ... . forced circulation 6. Heat source a. Fuel b. hot wastergaes c. electrical energy d. nuclear energy 

Description : Define dry bulb and wet bulb temperature.

Last Answer : i)Dry bulb temperature: Temperature recorded by ordinary thermometer is called dry bulb temperature.  (ii)Wet bulb temperature: It is the temperature indicated by thermometer whose bulb is covered with cotton or muslin wire wetted with moisture

Description : Define coefficient of performance.

Last Answer : Coefficient of Performance.: Working performance of any machine is usually expressed by output/input ratio known as efficiency. In refrigeration it is denoted by C.O.P. ( β ) . COP= refrigeration effect/ work input to produced R.E.  β=RE/W

Description : List out uses of air in industry.

Last Answer : Uses of air in industry: i) To clean work shop ,generators and machine. ii) For cooling of furnace. iii) Compressed air used in oxidation of acetaldehyde to acetic acid in liquid phase reactor. iv) ... To exhaust the fumes of HCl gas, by exhaust blower. vi) fan air used in solid fuel boiler.

Description : List out types of thermic fluid.

Last Answer : Different thermic fluids 1. Dowtherm A 2. Dowtherm E 3. Therminol FR 4. Oil mobiltherm 600 5. Oil Mobiltherm light 6. Hydrotherm 750-200

Description : Define enthalpy of steam with its unit.

Last Answer : Enthalpy of dry saturated steam. It is the quantity of heat required to raise the temperature of 1 kg of water from the freezing point to the boiling point and then convert it into dry saturated steam at that temperature and pressure. Unit: kJ/kg

Description : Define hard water and soft water.

Last Answer : Hard water: Contains dissolved salts of calcium and magnesium. It does not produce lather with soap solution.  Soft water: Does not contain dissolved salts of calcium and magnesium. It produces lather or foam with soap

Description : State the uses of Industrial water.

Last Answer : Uses of industrial water:  1. In chemical reaction 2. Utility(cooling agent) 3. Steam production 4. Cleaning 5. In cooling tower