Plant drainage

The hydraulic diagram should be fairly self-explanatory in terms of the previous calculations and the resulting plant elevations. Note that at the splitter box outlet, we have used a factor of 2.0 to calculate b. No factor is available from a documented source for this particular overflow box this comes purely from observations of the existing plant, but one could easily guess such a value by comparison with the theoretical value of 1.5 for a simple abrupt outlet. Note that in these calculations, we have relied where possible on the practice in a similar plant with a similar slurry in order to arrive at a design, which is always the preferred option. 

Plant drainage is an open-channel flow problem, but not one restricted to slurries. For all too many plant designs, drainage was a matter that received insufficient attention until too late, and consequently it has been one of the hardest problems to rectify. The result is plants with stagnant pools at various places, with the associated safety and corrosion problems and extra labour costs. 

The design issues for floor drainage and underground sewers are in fact exactly the same as for in-plant open-channel flow. Settlement of solids may be an issue if these are present in the process. The equations above indicate that, in the case of a floor, because the effective flow area is low in relation to wetted perimeter, a high slope is required and 

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A project to install decanting valves on surge tanks is also being undertaken to ensure automatic drainage of sealed water to the plant drainage system... 

Put the nylon stocking or cheesecloth on top of the charcoal. This nylon barrier will prevent the soil from dropping to the bottom of the container and mixing with the charcocd, clogging your plants drainage systems. 

Here we will address contained fluid handling systems the open-channel flow of fluids is included in Chapter 17, together with plant drainage. We will begin by addressing the transport of liquids in pipes. The transport of liquids in containers may be important outside plant limits, but it has little place in a continuous process plant and will not be discussed. 

Re-emphasizing the commentary made in Chapter 17 on the subject of plant drainage, it is essential (before releasing bulk earthworks and plant infrastructural designs for construction) to ensure that the layout and elevations employed correspond to a comprehensive and acceptable plant drainage design. 

Plant drainage system and implications for unit elevations. Prevailing winds and implications for plant layout. 

Identify watercourses, separators and plant drainage systems with the aim of minimising environmental pollution. Include areas where firewater run off can be contained. Identify equipment required to assist in this, eg drain sealing equipment, booms and fire service New dimensions pumping equipment. Consideration should be made of the resources held by Fire and Rescue Service (FRS) and how on-site resources will be used by FRS personnel. 

Soil conditioners are materials that measurably improve the physical characteristics of the soil as a plant growth medium. Typical uses include erosion control, prevention of surface sealing, and improvement of water infiltration and drainage. Many natural materials such as peat and gypsum are used alone or in combination with synthetics for soil conditioning. This article is concerned with synthetic soil conditioners, many of which are introduced as polymeric systems similar to the gels and foams formed in situ by chemical grouts. 

Steep-Angle Conical Bottoms. Tanks often have a conical bottom where the slope exceeds 15—20° from the horizontal. This provides for complete drainage or even soflds removal. Because these types of tanks are more cosdy, they are limited to smaller sizes. Such tanks are often found in the chemical industry or in processing plants. 

A common form of turbine pump is the vertical pump, which has the pump element mounted at the bottom of a column that serves as the discharge pipe (see Fig. 10-46). Such units are immersed in the liquid to be pumped and are commonly used for wells, condenser circulating water, large-volume drainage, etc. Another form of the pump has a shell surrounding the pumping element which is connected to the intake pipe. In this form, the pump is used on condensate service in power plants and for process work in oil refineries. 

A paint shop may pollute the surroundings in two ways first, by acid and paint fumes that contaminate the inside of the plant and also pollute the outside environment second, by the discharge of the pre-treatment tanks and oversprayed paint that pollute the drainage system or where it is finally discharged. 

Step 9.1 Identify the Effluent Discharge Points. Determine the points at which wastewater leaves the site. Wastewater may go to an effluent treatment plant, directly to a public sewer, or directly to a watercourse. One factor that is often overlooked in audits is the use of several discharge points. It is important to identify the location, type, and size of all discharge flows. Identify where flows from different unit operations or process areas contribute to the overall flow. In this way, it is possible to piece together the drainage network for the site. This can lead to startling discoveries of what goes where ... 

Disposal of Drainage of Process Equipment Contents - When items of onsite process equipment are taken out of service, either individually during plant operation or for general turnaround, means of draining and safe disposal of the residual liquid hydrocarbon contents must be provided. The following are important considerations and terminology in the design ... 

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