Pumping unit, requirements

Feed systems utilizing gravity are rarely used. Line pressure is usuaHy adequate for smaH systems. AuxHiary pumps are required in larger systems to assure proper flow through aH units and to avoid uneven flow should line pressure decrease as other demands for water or the process stream occur elsewhere in the facHity. 

The mass of air required to pump unit mass of liquid is, therefore, given by ... 

The maintenance is expected to be lower when compared to the conventional distributed water loop systems. A fan coil unit requires less maintenance than a heat pump due to fewer moving parts. 

The produced oil or gas is connected to surface flowlines from the wellhead pumping unit or surface regulating valve assembly typically referred to as a Christmas tree but to its arrangement. The flowlines collect the oil or gas to local tank batteries or central production facilities for primary oil, water, and gas separation. The reliability of electrical submersible pumps (ESPs) has increased to the point where the submersible electrical pump is commonly used for the production of liquid hydrocarbons where artificial lift is required for production. 

Operation of a system on a continuing basis requires regular monitoring and maintenance. This phase represents the largest cost items of a long-term project however, routine adjustments of pumping units, coupled with preventative maintenance, will result in lower long-term costs. 

The operation of an electrodialysis unit requires one or more pumps to circulate the diluate, the concentrate, and the electrode rinse solution through the stack. The energy required for pumping these solutions is determined by the volumes of the solutions to be pumped and the pressure drop. It can be expressed by ... 

Material handling can start with delivery of bulk plastic to the plant that can be by trucks or rail cars. Trucks typically carry 1,250 ft3 (36 m3) of material. Most often the truck has a positive displacement-pumping unit or the user supplies a pressure system to the silos. Rail cars can store up to 5,200 ft3 (148 m3) in 4 or 5 compartments with user providing unloading systems to the silos. Unloading costs are largely determined by the throughput required. 

The power P in Eq. (15-177) does not include losses associated with the motor and drive unit. These losses can contribute as much as 30 to 40 percent to the overall power requirement. The drive supplier should be consulted for specific information. For pump-mix impellers, knowledge of the power characteristics for pumping is required in addition to that for mixing. For a discussion of these special cases, see Godfrey,... 

The pump unit must be designed to operate at very onerous levels of pressure, temperature and in the presence of contaminates such as sand, acids etc. Moreover, the unit must be suitable for lowering into a well-bore which can vary from only 150 to 300 mm in diameter. Due to diametral limitations and the necessary power requirements the motor pump unit itself becomes extensive in length, e.g. up to 10 metres. See Reference 6 for an overview of the subject of submersible pumps. 

---