Floor capacity

Never use any powered equipment on a mezzanine unless an engineer authorizes this practice. Floor capacity is a serious consideration on mezzanines. 

Portable scales generally have a platform near the floor with the indicator mounted on a column for ease of operation. These scales may be on wheels, and many are battery-powered. Capacities are generally less than 600 kg. Bench scales can be placed on a wheeled table for similar use. 

Floor scales are platform scales which are permanently installed in a pit, flush with the floor, or which sit on the floor. These scales typically range in capacity from 500 kg to 30 t, and in size up to that required to accommodate a fork-lift tmck. 

Industrial appHcations often require that bulk materials or Hquids be weighed in hoppers, silos, tanks, or reactor vessels, referred to collectively as vessels. Because they come in such a wide variety of si2es, shapes, and capacities, scales using these vessels as load receivers are not typically available as standard products. Vessels are usually custom-fabricated to suit a particular appHcation, then mounted on a scale. Some can be mounted on a standard scale such as a bench, portable, or floor scale. More typically, a number of weigh modules are used to support the vessel. This offers the scale designer great flexibiHty but certain precautions are necessary in order to constmct an accurate scale. Some of the more important factors associated with the design of vessel scales are discussed herein. 

The uniqueness of methyl methacrylate as a plastic component accounts for its industrial use in this capacity, and it far exceeds the combined volume of all of the other methacrylates. In addition to plastics, the various methacrylate polymers also find appHcation in sizable markets as diverse as lubricating oil additives, surface coatings (qv), impregnates, adhesives (qv), binders, sealers (see Sealants), and floor poHshes. It is impossible to segregate the total methacrylate polymer market because many of the polymers produced are copolymers with acrylates and other monomers. The total 1991 production capacity of methyl methacrylate in the United States was estimated at 585,000 t/yr. The worldwide production in 1991 was estimated at about 1,785,000 t/yr (3). 

Cracking reactions are endothermic, 1.6—2.8 MJ/kg (700—1200 BTU/lb) of hydrocarbon converted, with heat supplied by firing fuel gas and/or fuel oil in side-wall or floor burners. Side-wall burners usually give uniform heat distribution, but the capacity of each burner is limited (0.1—1 MW) and hence 40 to 200 burners are required in a single furnace. With modem floor burners, also called hearth burners, uniform heat flux distribution can be obtained for coils as high as 10 m, and these are extensively used in newer designs. The capacity of these burners vary considerably (1—10 MW), and hence only a few burners are required. The selection of burners depends on the type of fuel (gas and/or liquid), source of combustion air (ambient, preheated, or gas turbine exhaust), and required NO levels. 

The heavy-duty jacketed type (Fig. ll-62a) is a special custom-built adaptation of a heavy-duty vibratory conveyor shown in Fig. 11-60. Its apphcation is continuously to cool the crushed materi [from about 177°C (350°F)] produced by the vibratoiy-type caster of Fig. 11-53. It does not have the liqmd dam and is made in longer lengths that employ L, switchback, and S arrangements on one floor. The capacity rate is 27,200 to 31,700 kg/h (30 to 35 tons/h) with heat-transfer coefficients in the order of 142 to 170 W/(m °C) [25 to 30 Btii/(h ft °F)]. For heating or drying applications, it employs steam to 414 kPa (60 IbFin ). 

Shelf area, m Floor s ace, m Weight average, kg Pump capacity, mVs Pump motor, kW Condenser area, m Price/m (1995) ... 

Working capacity, nd Total volume, nd Heating surface, ni Drive, kW Floor space, ni Weight, kg Purchase cost (1995) ... 

Size numher Capacity, U.S. gal Typical supplied horsepower Floor space, ft... 

The filter press has the advantage of simplicity, low capital cost, flexibility, and ability to operate at high pressure in either a cake-filter or a clarifying-filter application. Floor-space and headroom needs per unit of filter area are small, and capacity can be adjusted by adding or removing plates and frames. Filter presses are cleaned easily, and the filter medium is easily replaced. With proper operation a denser, drier cake compared with that of most other filters is obtained. 

Relatively expensive, but high capacity for a given floor space used for finer separations. 

When a forest system is subjected to acid deposition, the foliar canopy can initially provide some neutralizing capacity. If the quantity of acid components is too high, this limited neutralizing capacity is overcome. As the acid components reach the forest floor, the soil composition determines their impact. The soil composition may have sufficient buffering capacity to neutralize the acid components. However, alteration of soil pH can result in mobilization or leaching of important minerals in the soil. In some instances, trace metals such as Ca or Mg may be removed from the soil, altering the A1 tolerance for trees. 

Trays operate within a hydraulic envelope. At excessively high vapor rates, liquid is carried upward from one tray to the next (essentially back mixing the liquid phase in the tower). For valve trays and sieve trays,. i capacity limit can be reached at low vapor rates when liquid falls through the rray floor rather than being forced across the active area into tlic downcomers. Because the liquid does not flow across the trays, it rass.scs contact with the vapor, and the separation efficiency drops dramatically. ... 

The variation in temperature across the top and bottom halves of the mold is a function of the press platen size, the flatness of the mold and platen surfaces at the two mold/platen interfaces, the mold construction, and the platen heating system. The larger the platen size, the more difficult it is to maintain a constant temperature across the platen. Therefore, one solution to the problem is to use a large number of molding presses with a relatively small platen size, for example, four presses with platens 355 x 355 mm will have approximately the same production capacity as one press with a 710 x 710 mm platen. In reality, for high-volume production, large presses are more economical from the cost point of view and the floor space required. 

Floor loading capacity (point load, uniformly distributed load, line load)... 

In many instances, adequate existing civil/stmctural or services installation information may not be available. Guessing the likely bearing capacity of floor slabs, foundations, structural steel or sub-slab ground, etc. can prove disastrous. Equally, assuming likely operational conditions for new installations can lead to embarrassing (and quite possibly dangerous) under-performance. The cheapest or quickest installation is not always the best or... 

A store of the same capacity, designed to give immediate access to any one pallet, would have a floor area of 1260 m and a volume of 9600 m , giving a storage density of 94 kg/m . 

---