The Decanter
Of primary detriment to drilling fluids are ultra fine and colloidal size drill cutting particles.  These particles, if not removed create havoc in a variety of ways. They slow the rate of penetration compounding rig days and cost. They disrupt the drilling fluid rheology, especially gels strengths, thereby upsetting the ECD risking mud losses and worse creating potential blow out situations.  They cause for excessive dilutions to control fluid density thus escalating mud cost and worse contributing to environmental disposal problems by excessive mud buildup.  Ultra fine particles (5μ to 30 μ) and colloidal particles (0.1 μ to 5 μ) cannot be removed by shale shakers, de-sanders, de-silters, or mud cleaners.  Simply stated this equipment cannot provide enough particle acceleration, namely G-force to remove these minute particles from the fluid phase.  For example in this group, the de-silter, which is the highest “g” producer generates only ~800-g capable of making a particle size cut down to ~25 μ. So at their optimum performance this group of equipment can remove only the largest of the ultra fine particles.  Whereas the decanter, by producing up to 3000-g particle acceleration can remove all the ultra fines and make a cut down into the colloidal size range.  Drilling fluids made up of expensive polymers and oil base synthetics demand high performance decanters to control excessive mud cost.  Also as the drilling parameter become more and more complex, involving high temperature additives, etc., the need to remove ultra fine and colloidal particles from the mud is paramount.  This is the importance of high performance decanters.

Principle of Operation
Bowl Speed - Depending on the model specification, decanters are equipped with either fixed or variable speed arrangement on the main drive enabling the operator to adjust the bowl speed between 1200 and 3850 rpm within a few seconds.  This option, combined with variable conveyor speed, gives a unique dimension to the use of decanters for drilling fluids treatment. The optimum speed for solids removal for a specific cut point depends on the composition of the drilling fluid and the nature of the drill cuttings. 

Scrolling Speed 
Decanters are equipped with either fixed or variable back drive. The scrolling speed -(relative conveyor speed) can be changed in a matter of seconds by operations of a simple control switch. The optimum scowling speed is selected in each case according to solids load, required separation efficiency and required underflow density.  

Principle of Operation 

Bowl Speed - Depending on the model specification, decanters are equipped with either fixed or variable speed arrangement on the main drive enabling the operator to adjust the bowl speed between 1200 and 3850 rpm within a few seconds. This option, combined with variable conveyor speed, gives a unique dimension to the use of decanters for drilling fluids treatment. The optimum speed for solids removal for a specific cut point depends on the composition of the drilling fluid and the nature of the drill cuttings.

Scrolling Speed - Decanters are equipped with either fixed or variable back drive. The scrolling speed -(relative conveyor speed) can be changed in a matter of seconds by operations of a simple control switch. The optimum scowling speed is selected in each case according to solids load, required separation efficiency and required underflow density.
 
Pond Depth - The radical liquid level in the bowl is controlled by interchangeable level regulator plates, which are specially designed to minimize turbulence in the overflow from the clarifying zone. A shallow pond setting with a long beach gives a dryer solids discharge. A shorter pond setting with a short beach gives a clearer effluent. The unique design provided in allowing for differentiation in pond depth allows the operator to select the separation parameter best suited to the desired performance characteristic.

Feed Rate - In general a single drilling fluid decanter is capable of a process feed rate of up to 200 gpm. The treatment capacity is influenced by mud type and mud rheology. On drilling rigs it is common to utilize a minimum of two decanters installed in tandem for low weight muds and in series on high-density muds where barite recovery is necessary.

Available models
 
MKD - FTFB
Fixed main drive and fixed back drive speed. Bowl speed can be changed by changing pulley sizes on the main drive motor. Scroll speed alters as the main drive speed is altered. A set of pulleys is delivered with the machine to enable scroll speed changes by changing pulley sizes

MKD - FTVB
Fixed main drive and five speed back drive system. Bowl speed can be changed by changing pulley sizes on the main drive motor. Five back drive speeds are attained by a two speed brake motor, giving two speeds left, zero and two speeds right. This motor is controlled from the main control panel by a five position switch

MKD - VTVB
Infinitely variable  main drive and five speed back drive system. Bowl speed is controlled by a variable speed hydrodynamic coupling, allowing bowl speed control from 500 to 3250 rpm. Five back drive speeds are attained by a two speed brake motor, giving two speeds left, zero and two speeds right. This motor is controlled from the main control panel by a five position switch

Serviceability
Decanters are provided with 4 x service kits for each year period, one kit for every 2000 hrs of operations. If service is carried out each 2000 hrs with manufacturer genuine spare parts, decanting operations up time is maximized.

Dimensions and Utilities
Drilling mud decanters are designed to fit the space allocated on standard drilling rig pit systems. The standard footprint for a single decanter unit is L3.00 m x W2.00 m x H1.80 m and the electrical requirement, depending on the model, ranges from 50 kW to 60 kW.

Client references
Available on request