Lifting devices

Variable Flow Rate Conventional variable clearance volume and valve lifting devices are impracticable at high pressures and, should it be necessary to vary the flow rate, use has to be made of variable speed electric drives or magnetic clutches. Integral steam and gas engines have been used and Burckhardt (168) developed an hydrauhc drive to provide an integrated variable capacity machine, but its efficiency is less than that of a straight mechanical drive. 

Sedimentation systems consist of a collection of components, each of which can be supplied in a number of variations. The basic components are the same, whether the system is for thickening or clarifying tank, drive-support structure, drive unit and lifting device, rake structure, feedwell, overflow arrangement, underflow arrangement, instrumentation, and flocculation facilities. 

Rake blades can have attached spikes or serrated bottoms to cut into solids that have a tendency to compact. Lifting devices typically are used with these applications. 

Conflicting schedules with equipment such as lifting devices, safety apparatus, and mobile equipment. 

Fig. 3.31 The KAMINA demonstrator. The lifted device head shows the gradient microarray which receives ambient air by a fan. The complete microprocessor-controlled electronics is contained in the lower part of the device.

Figure 26 (A) and (B) Product discharge from the fluid-bed processing bowl using lift device. Source Courtesy of Niro Pharma Systems.

Bench or test stand testing Testing of a pressure relief device on a test stand using an external pressure source with or without an auxiliary lift device, to determine some or all of its operating characteristics, without necessarily flowing the rated capacity. This is required on a regular basis when the valve is taken into the maintenance cycle (see Chapter 10) at least to see that there is no shift on the set pressure and that the valve would open correctly during a pressure upset. 

Lifting device/lift lever A device for manually opening an SRV by the application of an external force to lessen the spring loading which holds the SRV closed. This allows the SRV to open manually below set pressure. 

Portable sampling devices were categorised by Nielsen and Yeates (1985) as grab samplers, suction lift devices and positive displacement mechanisms. A brief review of each category is given below. 

The principle of the reactor with an elevator in Pyrex glass (139,178) is given schematically in Fig. 15. The Pt/Al203 catalyst (20-30 mg) is placed at the bottom of a pyrex nonporous pan (A) and is covered by 1 g of silica held in a pyrex holder (B) with a porous glass bottom (position L). The lifting device (C) allows the removal of the catalyst (with some silica) in the pan, which is suspended by an inert wire and glass rod and is raised to position H. The stopcock (D) isolates the catalyst in the pan from silica in (B) during the catalytic run. 

The use of personnel protective equipment to protect eyes, ears, hands, feet, body, chest, and respiratory protection, harness, and mechanical lift devices... 

Motorized rake-lifting devices typically are designed to allow for a vertical lift of the rake mechanism of up to 90 cm (3 ft). 

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