1 – an artificial conduit or system of conduits used to carry and remove sewage and to provide drainage;
2 – human liquid waste;
3 – vertical pipes, which connect the mains to the surface;
4 – large pipes that transport storm water runoff from streets to natural bodies of water or absorptive areas, to avoid street flooding;
5 – a sewer system that is not a set of storm drains but is used to remove human waste;
6 – a metal frame covering the vertical pipes to prevent large objects from falling into the sewer system;
7 – a well which is situated immediately below the vertical pipes connecting the surface to the storm sewers;
8 – a conduit or a system of conduits used to collect storm water.
V. Writing Section.
Read and translate the following text using a dictionary.
A pump is a device used to move liquids or slurries. A pump moves liquids from lower pressure to higher pressure, and overcomes this difference in pressure by adding energy to the system (such as a water system).
Pumps work by using mechanical forces to push the material, either by physically lifting, or by the force of compression.
The earliest type of pump was the Archimedes’ screw (Архимедов транспортирующий винт), first used by Sennacherib, King of Assyria, for the water systems at the Hanging Gardens of Babylon and Nineveh (г.Ниневия, в Ассирии) in the 7th century BC, and later described in more detail by Archimedes in the 3rd century BC. In the 13th century AD, al-Jazari described and illustrated different types of pumps, including a reciprocating pump (насос поршневого типа), double-action pump (насос двустороннего действия) with suction pipes, water pump, and piston pump.
Types. Pumps fall into two major groups: rotodynamic pumps (центробежные) and positive displacement pumps (вытесняющего действия). Their names describe the method for moving a fluid. Rotodynamic pumps are based on bladed impellers (лопастные мешалки) which rotate within the fluid to impart a tangential acceleration (касательное ускорение) to the fluid and a consequent increase in the energy of the fluid. The purpose of the pump is to convert this energy into pressure energy of the fluid to be used in the associated piping system.
Application. Pumps are used throughout society for a variety of purposes. Early applications includes the use of the windmill or watermill to pump water. Today, the pump is used for irrigation, water supply, gasoline supply, air conditioning systems, refrigeration (usually called a compressor), chemical movement, sewage movement, flood control, marine services, etc.
Because of the wide variety of applications, pumps have a lot of shapes and sizes: from very large to very small, from handling gas to handling liquid, from high pressure to low pressure, and from high volume to low volume.
Pumps as public water supplies. One sort of pump once common worldwide was a hand-powered water pump over a water well where people could work it to extract water, before most houses had individual water supplies.
Today, hand operated village pumps are considered the most sustainable low cost option for safe water supply in resource poor settings, often in rural areas in developing countries. A hand pump opens access to deeper groundwater that is often not polluted and also improves the safety of a well by protecting the water source from contaminated buckets.
2. Answer the following comprehension questions:
1. What is a pump?
2. What is the principle of its work?
3. Which pump is known to be the earliest? Where was it applied?
4. What major groups do all pumps fall into?
5. What is the principle of work of positive displacement pumps?
6. What is the principle of work of centrifugal pumps?