Operating labour requirements

It is not known whether this process would be competitive with the lime/soda precipitation process for primary treatment. For new plants, the main issue is capital cost. The lime/soda process is relatively inexpensive for large-scale plants. For small plants, the BDFI system may be competitive, particularly for packaged turn-key plants, if installation and start-up costs are taken into consideration. The BDH system is very compact and can be quickly started and easily operated with minimal labour requirements. 

In the first years of operation, operating persoimel are required to a level of 75 h/day, seven days per week for monitoring (note that chemical and radionuclide analyses are not included in this costing), visual inspection and minor repair works. These expenses will be reduced over time when more statistical data become available from the wetland operation. Labour costs are estimated at about 30/h. 

Table E.4 in Appendix E provides a breakdown of the total production costs encountered in the manufacture of nitric acid. The costing is based upon paying the full market price for ammonia feed (at A 300/tonne). All tangible input and output valuesarecalculated using the results of the mass and energy balances detailed in Section 7.3. Labour requirements are evaluated assuming only two operators per shift and the usual labour maintenance requirements for nitric acid plants (see Ref. CE1 1).

First it should be very easy, so as not to require any great physical labour whereby a violent corporeal force is applied to the subject. Secondly, it should be simple, or not compounded of various concurrent operations nor require a variety of instruments. Thirdly, the change it makes should not be very remote from the nature of the subject. Fourthly, the effect produced should rather consist in a separation of the parts, such as they were originally, than be changed by the operation. 

The new method is easier to operate and does not require such highlx skilled workers as in the older methods. Because of increased production pe. line, labour requirements are much reduced. 

The labor requirement for a chemical processing unit can also be related to size (capacity). If 32 people are required to operate a 100 tonne/day sulfuric acid plant, what would be the estimated labour requirement for a 1,000 tonne/day plant ... 

Historically, these operations were very labour intensive. However, mechanisation, which started in the late 1940 s in Europe, and is currently being applied in most of the developing countries of the world, has dramatically reduced labour requirements. This section, therefore, concentrates on mechanised quarrying practices. 

The general trend with plant unit operating costs is for this to increase with reduced throughput and with more than one process operation in an Ausmelt furnace. However, in some circumstances unit operating costs may actually be reduced when switching from a two furnace to a single furnace operation because of a reduced labour requirement, when this can be sustained. 

With estimates of variable cost and capital requirement available the process cost table could be built up if an estimate of the labour requirement (process and maintenance and analytical) could be made. These items form part of the plant fixed costs and studies of a number of petrochemical processes show that an annual charge equivalent to 3-6% of the plant capital would be a suitable figure to include in a preliminary estimate for total plant fixed costs. For smaller batch operations a range of 8-12% of plant capital would be a reasonable figure to apply. A comprehensive cost table (Table 6.12) can then be built up. 

Filter presses are not at all suitable for the filtration of the large quantity of solids involved in the processing of low-grade ores. The large labour requirement for these filters can be reduced by designing them to operate on a continuous automatic cycle, but their throughput is still relatively low. 

Operators can spend less time working in the tankhouse searching for faults, and can spend more time rectifying them at the earliest opportunity. This may reduce labour requirements. 

The demands on the machines are best characterised by Mike Franke, vice president and chief engineer of Santa Fe Manufacturers must continue to produce automated equipment that minimizes the amount of manual labour required.High productivity is essential. Two criteria must be met Unit costs must be minimized by reducing the amount of labor required to operate and support the work equipment, and the units produced per on-tack hour must be increased.Manufacturers must design equipment with ... 

This type of contract requires the operator to pay a fixed amount to the contractor upon completion of the well, while the contractor furnishes all the material and labour and handles the drilling operations independently. The difficulty with this approach Is to ensure that a quality well Is delivered to the company since the drilling contractor will want to drill as quickly and cheaply as possible. The contractor therefore should guarantee an agreed measurable quality standard for each well. The guarantee should specify remedial actions which will be implemented should a substandard well be delivered. 

Typical units for productivity are kg m 3 h 1. Factors that influence productivity include the production time of the fermentation, the time required to dean and set up the reactor, the sterilisation time and the length of the lag phase of growth. Figure 2.2 shows how total productivity and maximal productivity can be calculated for a batch fermentation. The dedsion as to when the fermentation is terminated (maximum or total productivity) depends on the operating costs, which include the capacity of the fermentation vessel, energy costs and labour costs. 

Availability constraints the macroscopic limits on material resources and the availability or up-time of equipment. Availability of raw materials is an obvious constraint at scheduling. Obviously, no catalytic hydrogenation can be done if the catalyst is unavailable. Simultaneous operation of certain tasks is restricted by the limited availability of common utilities such as steam, electricity, or labour. The priority sequence in a product chain needs to be respected by ensuring that intermediate products are manufactured in time to be available when required by a batch of the consecutive product. 

Usually it is difficult to justify pressure-resistant construction in the case of extreme operating pressures because of the necessary material strength (JW wall thickness) needed. In individual cases it can also be difficult and labour-intensive to design a vent system for safe venting via pressure relief devices. This can be the case when catch systems are required. A separate document details the conditions and how safe venting from pressure relief systems can be achieved. 

In principle, any catalyst developed in the laboratory can be manufactured in large scale. In practice, however, the necessary investments, which may include development of the production process, and die operating costs of the catalyst production plant including availability and cost of raw materials, plant maintenance, labour etc. may not be justified by the market potential. In the VK69 case, production in the existing plant according to the route in Fig. 8 was preferred but not a strict requirement. 

Operating costs for injection wells are significantly lower when compared to capital costs. They include labour for operation and maintenance, chemicals for pretreatment, and power for pump operation (Mickley 2006). During operation of the well, the power required for pumping is the most significant cost (Mickley 2006). 

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