Recycling coefficient

A low-recycling boundary for a magnetically confined plasma may offer benefits from the point of view of confinement, however it presents other problems, for example with respect to fuelling of the confined plasma. While a solid wall in a long pulse device offers effectively 100% recycling from the surface, lithium effectively offers zero. Other flowing liquids may offer the possibility of a recycling coefficient somewhere in between these two extremes. 

Here the coefficient of is the recycling coefficient K. It will easily be seen that... 

In the very simple case being considered here, the recycling coefficient Kn denotes the ratio between the total reactor charge g and the fresh feed stock go. 

The recycling coefficient is required to determine, in the steady state ... 

In this case, with f = 0-8, the recycling coefficient is determined as follows ... 

In making calculations for cases where part of the recycle material (1 — ) is removed for immediate use, the proportions by weight of the recycle material returned to the process will equal of, and the recycling coefficient will be determined by the expression ... 

F. Connexion between reaction time and recycling coefficient ... 

The expressions for the recycling coefficients of each separate component will differ slightly. If the quantity of the unreacted component is a fraction a l of initial quantity of that component, then... 

From these expressions we can derive the following relations for the recycling coefficients for each component ... 

From (1.24) and (1.22) we get an expression for determining the recycling coefficient of a multi-component system in which the entire unreacted raw material is recycled ... 

When the system is supplied with a mixture of a large number of components, the total and component recycling coefficients can be determined from the following system of equations ... 

From (1.28) and (1.27) we get a relation for determining the recycling coefficients of a multi-component system with repeated processing of part of the unreacted raw material ... 

The recycling coefficient, reckoning on the basis of the fresh benzene alone, is ... 

The recycling coefficient and the material balance. As will be seen from Fig. 7 and the material balance given therein, the deep-cracking furnace is fed with raw material (reflux) obtained from the light-cracking furnace at a rate of 470 tons/day. The charge of the deep-cracking furnace (recycle material) is 1410 tons/day. 

System (2.5) gives a general solution for the problem of making a quantitative assessment of recycling processes. If the numerical value of each and of the fresh charges is known, it is possible to determine the recycling coefficients and to calculate the material balance for any plant with the flow system illustrated in Fig. 9. 

Equation (2.6) is absolutely identical with the equation of the recycling coefficient givenj above (1.5). Thus equation (1.5) is a very simple special case of the use of (2.6). 

If several substances react chemically in the system and it is necessary to determine the yields of the products from one of the types of fresh feed stock, then the recycling coefficient should be determined as the ratio between the charge of a given reaction plant, and the quantity of the raw material on the basis of which the yields of the reaction are determined. 

The recycling coefficients Kn of the individual sections of the plant being considered can be found by dividing both sides of equations (2.17) and (2.18) by gio. and can then be used to calculate the material balance ... 

Multiplying this yield by the recycling coefficient of the alkylation section, we get the yield of iso-octane relative to the fresh feed stock ... 

Knowing the recycling coefficients, it is not difficult to find the yields of the products obtained from the complex of the processes. 

In order to establish the balance of the process taking recycling into account, it is necessary to calculate the recycling coefficients for each reactor ... 

Knowing the magnitudes of the recycling coefficients of each reactor, we can determine the yields of the products from each process as a percentage of the sum of the charges of all the reactors and also in absolute quantities. 

Product s s 0 y C3 g O US 8 Recycling coefficient Kr, = Yield of product taking recycling into account Components of raw stock ... 

Since the fresh feed stock charge of the reactor is a known and constant quantity, in order to determine the recycling coefficient it is necessary to calculate the total reactor charge (fresh feed stock+recycle material) after the steady state has been reached, when for the process being considered the quantity of recycle material becomes virtually constant. 

The recycle coefficient for the cracking of the light recycle material is ... 

To calculate the final material balance we derive the equations that are necessary for determining the recycling coefficients of the crackmg and debitumenization sections. 

According to (5.28) and (5.29), the recycling coefficient for the debit-umenization section is ... 

From the experimental data obtained in the laboratory it is possible to determine the recycling coefficient of heavy reflux required for calculating the output of the furnaces of thermal cracking plant. 

As will be seen from Table 45, the amount of recycle material that has accumulated from 15 cycles by the time the steady state is reached is 44-7 per cent by weight of the charge of fuel oil, i.e. the accumulated amount is 2-482 times the amount of heavy reflux produced on primary cracking. Hence, in the steady state of the process for each 100 tons of fuel oil 44-7 tons of heavy reflux will be recycled. In this case the recycling coefficient will be ... 

The composition of the light-cracking products at the outlet from boffi furnaces, can be calculated from the recycle coefficient on the basis of the available data (Table 51). 

The recycling coefficient of light-cracking furnaces was determined from the equation ... 

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