Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations MintJulep on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  • Users: virk
  • Content: Threads
  • Order by date
  1. virk

    Pressure loss in shell side of shell&tube heat exchanger with baffle plates

    Following scenario: Shell&tube heat exchanger will be designed with f.e. pressurized water flowing on shell side. Baffles are to be installed to increase heat transfer. Now my topic: I would assume that there will be "normal" friction losses due to contact of water with wall; but also I assume...
  2. virk

    Condensation of carbon dioxide with "small" amount of gaseous hydrogen

    We are trying to find out the design criteria for a heat exchanger which condenses carbon dioxide. What makes it somewhat tricky is the fact that a yet unknown small (0-10 mass percent) amount of hydogren will be in the gas flow, too. (Evaporating ammonia will provide the refrigeration) There...
  3. virk

    Cooling water consumers approx. 10-15m higher than cooling towers

    We are considering an installation with an open cooling tower mounted nearly on ground floor (pumps below) while the consumers will be elevated about 10-15m higher. Cooling water flow will be about 500 m3/h. 1) Concerning this I would like to know whether it is "allowed" to operate the return...
  4. virk

    Desuperheating necessary/senseful

    With a shell&tube heat exchanger we need to heat an ammonia/water-solution. On the tube side will be the heating steam. The condensing pressure of the steam will be about 2.8 bar absolute. The steam is provided with a pressure slightly higher and/but with a temperature of about 371°C. Customer...
  5. virk

    P&I-D-drawings with Mac-computers

    What program(s) do you suggest for the drawing of process&instrumentation diagrams (P&I-D) with Mac-computers? Is there any experience? Kind regards virk
  6. virk

    NH3 refrigeration plant Mexico; Design Pressure

    We have the order for an NH3 refrigeration plant for the south of Mexico. We need to know the required design pressures there for as well low pressure section as high pressure section. (We have agreed that the design code for pressure vessels to follow will be PED (European Pressure Directive)...
  7. virk

    Suction line diameter of saturated liquids

    Hello! I have one question which some of you perhaps can answer: We often design suction line of saturated liquids like ammonia in a way that the velocity in this suction pipe is about 0,8 m/s. Additionally we consider NPSH issues. We never had problems. My problem is that I do not know why it...
  8. virk

    Impingement air cooling/freezing on belt

    Hello! Above a belt of about 20m length and 2 m width we will install an impingement cooling "system" with cold air for to cool down the product being transported on this belt. We already installed one of these systems successfully, so there is already some experience. I want to learn more...
  9. virk

    Direct expansion ammonia evaporator/condenser

    Hello! Perhaps somebody of you has little information and/or experience about the following cascade heat exchanger application: Because of low space we want to use a plate heat exchanger for condensing ammonia at -38°C (-36.4F) by evaporating ammonia at about 4K colder on the other side of the...
  10. virk

    Baltimore (NH3) Hybrid condenser HXC

    Hello! We are going to install 3 hybrid condensers HXV for condensing NH3. These are equipped with one (dry) finned tubes section at the top and with a (normally wetted) tube section below. During cold periods main load shall be covered by the dry section. During hot periods the normal wetted...
  11. virk

    Design pressure ammonia refrigeration India

    I was asked about pressure design conditions for an ammonia refrigeration system in India for rough budgetary costs. Who of you can guide me to an appropriate site or can give some information about pressure design conditions there. (I know min. design pressure in Germany is 16 barg high...
  12. virk

    Cooling tower parallel 3 pumps

    We are designing cooling tower cycle with similar 22 consumers. Each consumers requires max. flow of 50m3/h cooling water. Design flow of cooling tower cycle is 300m3/h. Considered worst case is 8 consumers in operation. We want to install 2+1 cooling water pumps, each of them delivering...
  13. virk

    Control of cooling tower circuit

    We are designing a cooling tower circuit. In total 22 similar consumers of cooling water will be connected in parallel. We will install one large supply and one return line, where all the 22 consumers are connected to. Each consumer is provided with a control valve in the outlet for...
  14. virk

    Boiling of mixture of ammonia and water

    Hello! I have a question concerning the boiling of an 30%-ammonia/water mixture at approx. 110°C and 12 bara. I am trying to find appropriate equations for to describe the heat transfer coefficient relating to the actual concentration of the mixture. I think (expect) there is a large...
  15. virk

    Inhibitor Na2Cr2O7 alternative for ammonia/water carbon steel

    Hello! We use the salt Na2Cr2O7 as corrsion inhibitor for ammonia/water solution to protect the carbon steel equipment. This corrosion inhibitor is well known since a hundred years, but more or less toxic. Is there any proven alternative available? Will ammonia/water NOT affect stainless...
  16. virk

    Corrosion in gas nozzle of ammonia/water 180¦C boiler

    Hello! I would like to get some advice of the following corrosion problem: In a boiler (more or less directly gas fired steam boiler) a mixture of ammonia and water boils at 175°C and 12 bara. The boiler is provided with several level gauges, which are examined periodically. After approx. 2...
  17. virk

    Decreasing flow at higher opening of valve

    A customer of us describes the following problem: In an ammonia (absorption) refrigeration installation one expansion valve group consists of shut-off valve DN25, control valve DN25, shut-off valve DN150 (expansion has taken place). Between first shut-off valve and control valve a pressure...
  18. virk

    "PBP" ball valve

    Perhaps anybody can help me? A friend in a german news group asks, what the abbreviation "PBP" on a ball valve means. Finally he wants to know the manufacturer. He thinks, it is an american product. Kind regards Virk
  19. virk

    alternating flow through heat exchanger

    Who can help me? We use a plate heat exchanger for to change heat between two fluids similar to water. Hot side always enters with constant temperature and constant flow. Cold side enters with constant temperature, but changing flow due to control valve which controls level somewhere. So not...
  20. virk

    Conductivity ammonia

    Hello! Who of you knows the conductivity of liquid ammonia (mS/cm)? I don't find anything on the web...It's (I am:-)) unbelievable. I need it for the decision whether a certain level switch can be used. Kind regards

Part and Inventory Search

Back
Top