Corea Derrick Submitted 2018-01-11 04:34:01 Repeated attempts to use a conventional centrifugal pump for handling compressor interstage liquids failed. The compressor recovered fuel from a flare-gas system by condensing light hydrocarbons in the interstage coolers and aftercoolers. The compressor suction operated at around 1 psig Cheap Roberto Gagliardini Jersey , the interstage at 19 psig and the discharge at 160 psig. The original intent was to send the recovered liquids to other units. However, the pump suffered from repeated failures due to low available net positive suction head (NPSHA), difficulty in control, and extreme variations in flow rate and composition.
As a temporary solution, liquids were recycled from the interstage and aftercooler drums to the suction drum by pressure. This created several problems: Liquid recycle built up during operation Cheap Rigoberto Rivas Jersey , gas recovery from the flare system was reduced, and compressor reliability problems were created. So, a project was started to find alternative destinations for the liquid streams.
Three possible downstream locations were identified, but none would work at every operating condition. The pressures at these destinations were 190 psig, 230 psig and 290 psig; to reliably send the liquid to any of these required extra equipment.
The root cause of the problem was the original compressor installation. The exchangers and drums were built too low. Pump selection can never solve a poor design. However Cheap Miranda Jersey , when you have to live with a situation, you make the best choice you can.
Insufficient NPSHA, lack of attention to control arrangements and ignoring off-design operation are the major process-design contributors to pump problems. This unit suffered from all three.
Conceptual process engineering identified new pumps as necessary. Piston pumps with variable-speed motors appeared to be the only choice to meet the constraints of discharge head, available suction head, and flow-rate flexibility. The interstage drum and the aftercooler drum would each have separate pumps Cheap Milan Skriniar Jersey , and variable-speed drives would control the flow rate. The piston pumps would be able to deal with the full flow-rate range, composition variations and low suction head. Essentially, this duplicated the intent of the original process design, but would work. However, appropriate control systems for the two pumps were very expensive in both capital and maintenance.
So Cheap Mauro Icardi Jersey , alternative options to reduce the investment and operating cost were reviewed and a list was made of why they were discarded. From this list, one key factor stood out. The major constraint that eliminated many other choices was the need to have a 271-psi differential pressure rise for the interstate drum liquids (19-psig suction to 290-psig discharge). If that limit could be relaxed, then much cheaper solutions were available.
When faced with difficult equipment constraints, never forget to reexamine the process. Process and equipment choices interact; equipment is not independent of the process. Modifying the liquids handling (Figure) by routing the interstage liquids to the aftercooler drum reduces the head required for the first stage liquids from 271 psig to 141 psig. Sliding vane pumps are a practical choice for a 141-psig rise as they work well in a differential pressure range of 160-180 psi, maximum. The new configuration uses sliding vane pumps with variable-speed drivers. The result: Capital was reduced by 50% and maintenance costs were lowered as well.>ESSENTIAL KEY AREAS OF PERMACULTURE DESIGN Posted by permaculture on July 23rd Cheap Matias Vecino Jersey , 2019
Having your own grown fruits and vegetables to eat is enormously beneficial. It has lots of health benefits. Growing fruits and vegetables needs a large part of the backyard where Permaculture can be designed. But for this first, you need to learn about PDC online. If you know how to design Permaculture then you can grow your own healthy food.
Permaculture is a complex system of sustainability. Your backyard must have the productive benefits of Permaculture with a calm and relaxing space that can help to restore balance to a stressful life.
The essential key areas of the Permaculture design system are:
Water- The water is the most essential part of Permaculture. Water is the basis of life. Everyone needs water to drink, including humans, animals, and plants. We need water to wash Cheap Marco Pissardo Jersey , clean things and cook. Rainwater tanks are the key feature of Permaculture. You can also collect the grey water for watering the garden. Swales are also used to collect and limit the flow of water.Animals- Chickens provide you a regular supply of eggs and meat. Similarly, rabbits also provide supply of meat and fur. You need to choose the right breed of rabbit for your small backyards. Young rabbits are usually ready to eat between 8 to 12 weeks of age. Whereas in larger backyards, goats, pigs, cattle Cheap Marcelo Brozovic Jersey , and sheep provide you meat, milk, and leather.Power Creation- A varied range of power supply is observed in Permaculture systems. The power supply varies from backyard wind generation to generators to solar panels. Permaculturists try to use self-sufficient power but mains electricity is also required in some circumstances.Shelter- Many people construct their homes on the basis of Permaculture designs. These homes are made of mud bricks. Various traditional building materials and methods are also used by the Permaculturists.Fruit, vegetables, and grains- The Permaculture design is also used to grow fruits Cheap Jonathan Biabiany Jersey , vegetables and grains organically. You can grow many of the vegetables, and green salads throughout the year.
Forum zum Block von Just4Fun
Thema drucken
04.01.2020 07:03
Antworten
