System for handling the underflow from a primary separation vessel in the tar sand hot water process

Patent · Tue Aug 08 04:00:00 EDT 1978

OSTI ID:7132690

McQuitty, S

For operating control and safety, a variable-speed close-coupled pump is directly connected to the underflow of the primary separation vessel (PSV). The desired discharge density of the PSV is 70--80% solids in order to minimize bitumen losses. For a good pumping system, the pump discharge density should be less than 65% solids to avoid settling out of the solids in the downstream conduit. Therefore it is necessary to dilute the PSV underflow before it reaches the pump. Secondary flotation tailings, a dilute stream containing a high proportion of fine solids, is used for this purpose. The solids content of the PSV underflow is monitored by one of two alternative systems, a torque recorder on the PSV rake shaft or a density gauge on the PSV underflow conduit. The former is used when the PSV is being fed low fines tar sand; the latter, when it is treating high fines tar sand. The close-coupled pump speed is adjusted relative to the solids content measurement to keep it at the desired 70--80% level. The density of the stream at the pump discharge is also monitored and the measurement is used to control the amount of secondary flotation tailings added. By the use of the controlled-speed, close-coupled pump, a closed system for controlling underflow density is provided. By using secondary tailings as diluent, water requirements for the process are reduced and a pumpable mixture is provided from which the solids do not readily settle out. 1 fig.

• Assignee: Minister of Energy, Mines and Resources, Ottawa, ON (Canada); Dept. of Energy and Natural Resources, Edmonton, AB (Canada); Ontario Energy Corp., Toronto, ON (Canada); Imperial Oil Ltd., Toronto, ON (Canada); Canada-Cities Service, Ltd., Calgary, AB (Canada); Gulf Oil Canada Ltd., Toronto, ON (Canada)
• Patent Number(s): US 4105537; A
• Application Number: PPN: US 5-774927
• OSTI ID: 7132690
• Country of Publication: United States
• Language: English

Related Subjects

04 OIL SHALES AND TAR SANDS
040402* -- Oil Shales & Tar Sands-- Surface Methods
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CONTROL
ENERGY SOURCES
FLUID INJECTION PROCESSES
FOSSIL FUELS
FUELS
HOT-WATER PROCESSES
MATERIALS
MITIGATION
OIL SAND TAILINGS
OIL SANDS
PARTICLE SIZE
PROCESS CONTROL
PUMPING
PUMPS
RESOURCE CONSERVATION
RESOURCES
SEDIMENTATION
SEPARATION EQUIPMENT
SIZE
SOLID WASTES
TAILINGS
WASTES
WATER RESOURCES