794 results about "Pump chamber" patented technology

A pet water dispenser includes a water tank for storing liquid, an upper cover installed above water tank and having a sink and a water leakage opening communicating with water tank in surface, a water pump extending into or onto upper cover from lower part of water tank and having a water supply opening in surface above upper cover; water pump includes a first accommodating chamber internally having a motor which drives pump blades below first accommodating chamber to rotate through a rotating shaft, second accommodating chambers of which walls define a pump chamber with downwards-extended wall of first accommodating chamber; a centrifugal water pump formed by pump blades in pump chamber and matched motor and including a water inlet communicating with water tank, and a water discharging opening; a water supply channel formed by second accommodating chambers sequentially communicating with water discharging opening and water supply opening.

A vacuum pump, which is connectable to an external system and configured to evacuate material from the external system, includes a main housing defining a motor housing, a pump housing, and a partition wall that separates the motor housing and the pump housing. The pump housing is sealed relative to the motor housing to form a compression chamber that holds a lubrication fluid. The vacuum pump further includes a motor assembly that is positioned within the motor housing and a pump assembly that is positioned within the compression chamber. The pump assembly is driven by the motor assembly and is in fluid communication with the compression chamber. The pump assembly includes a pump chamber, a rotor having vanes that is driven within the pump chamber, and a seal that is in sliding contact with the rotor. The seal is moveable relative to the rotor.

A pumping system, comprising: a pump fluid end comprising a plurality of pump chambers, each pump chamber comprising a bore having a reciprocatable plunger disposed therein, a suction valve, and a discharge valve; a prime mover mechanically coupled to the fluid end [by a drivetrain] and configured to reciprocate the plungers; and a controller communicatively coupled to the prime mover, the fluid end, or both and configured to alert a user re a pump malfunction, initiate corrective action of the pump malfunction, or both in response to: (a) an indication of torque reversal during operation of the pumping system, (b) an indication of negative flow rate from the pump during operation of the pumping system, (c) an indication of leakage of (i) a single discharge valve in a 3-plunger pump or (ii) discharge valves associated with two plungers in adjacent firing order, or (d) any combination of (a)-(c).

A novel embodiment of a pump system, for example, of the type that would be used in a wearable drug delivery system, comprises dual linear-actuated plungers disposed in a pump chamber. The plungers are coupled to a leadscrew having both left-hand and right-hand threads such that rotation of leadscrew in a first direction moves the plungers together and rotation of leadscrew in a second, opposite direction moves the plungers apart. Movement of the plungers away from each other draws one or more doses of a liquid drug from a reservoir into the pump chamber, while movement of the plungers together forces liquid drug to a patient interface for delivery to the patient.

What is suggested is a micromembrane pumping device for pumping a fluid, having: a pump chamber to which an inlet valve, an outlet valve, and a membrane device for varying a volume of the pump chamber are associated, wherein the membrane device has a plate-shaped actuator for deforming the membrane device; and influencing means for influencing the plate-shaped actuator and the volume of the pump chamber; wherein the membrane device has a plate-shaped membrane body limiting the pump chamber; wherein the plate-shaped actuator is arranged on a side of the plate-shaped membrane body facing away from the pump chamber; wherein the plate-shaped actuator is mounted to and electrically insulated from the plate-shaped membrane body by an electrically insulating glue layer; wherein at least one embedded portion of a support body at or in which a deformation sensor for detecting a deformation of the membrane device is arranged, is arranged within the glue layer to detect the volume of the pump chamber; wherein the influencing means, the plate-shaped actuator and the deformation sensor form a closed-loop control circuit for regulating a volume flow.

The invention relates to the technical field of self-sucking pumps, in particular to an efficient vacuum energy-saving self-sucking pump which comprises a base, a first pump cavity, a motor, a rain baffle, a first impeller, a compensation assembly and a drainage assembly, the first pump cavity, the motor and the rain baffle are sequentially installed at the upper end of the base, and the first impeller is installed at the axis position in the first pump cavity; the drainage assembly is installed at the lower end of the first impeller, and the two compensation assemblies are installed in the drainage assembly. After the drainage assembly is started, the drainage assembly is used for guiding the liquid level to overflow the first impeller and removing large-particle solids in fluid, and the compensation assembly drives the first impeller to move downwards to reduce the gap when detecting that the gap between the first impeller and the inner wall of the first pump cavity is enlarged. The tip end of the blade is easily and continuously washed by solid particles, so that the flow and lift of the core pump are reduced, and the efficiency is obviously reduced.

The invention discloses dispersing equipment. The dispersing equipment comprises a dispersing part and a driving part, the dispersing component comprises a rotating shaft, a dispersing machine and a centrifugal pump. The dispersion machine comprises a dispersion main body and a screen cylinder. And the dispersing main body is provided with a dispersing cavity for accommodating the screen barrel. The centrifugal pump comprises a pump shell and an impeller. The rotating shaft is sequentially and fixedly connected to the screen barrel and the impeller. The pump shell is provided with a pump cavity, a feeding port and a discharging port. The impeller is arranged in the pump cavity. The discharge hole is formed in the end part, far away from the dispersion machine, of the pump shell. The pump shell is provided with a side flow channel. And a discharge port is formed in the discharge end of the side runner. And the feeding end of the side runner and the feeding hole are oppositely arranged in the axial direction of the rotating shaft. And the feed port, the pump cavity, the side runner, the discharge port and the dispersion cavity are sequentially communicated and form a slurry runner. And the driving part is fixedly connected with the rotating shaft and is used for driving the rotating shaft to drive the screen barrel and the impeller to rotate, so that the control difficulty of the material retention time and the shearing strength is reduced, the consistency of material characteristics is improved, and the material dispersion quality is improved.

The invention relates to a device for dispensing a liquid from a container, comprising: - an inlet channel configured to be brought in fluid communication with the container; - a pump in fluid communication with the inlet channel, the pump including a pump chamber and a piston reciprocally movable in the pump chamber; - an inlet valve arranged between the inlet channel and the pump; - a buffer facing the pump and in fluid communication therewith; - a nozzle for dispensing the liquid, the nozzle in fluid communication with the pump and / or the buffer; and - an outlet valve arranged between the pump and / or buffer and the nozzle; wherein the buffer comprises an elastic buffer bag defining an expansible volume and extending at least substantially in alignment with the pump chamber. The invention further relates to a system for dispensing a liquid, comprising a container and a liquid dispensing device as described above connected thereto.

Improvements in fluid volume measurement systems are disclosed for a pneumatically actuated diaphragm pump in general, and a peritoneal dialysis cycler using a pump cassette in particular. Pump fluid volume measurements are based on pressure measurements in a pump control chamber and a reference chamber in a two-chamber model, with different sections being modeled using a combination of adiabatic, isothermal and polytropic processes. Real time or instantaneous fluid flow measurements in a pump chamber of the diaphragm pump are also disclosed, in this case using a one-chamber ideal gas model and using a high speed processor to obtain and process pump control chamber pressures during fluid flow into or out of the pump chamber. Improved heater control circuitry is also disclosed, to provide added or redundant safety measures, or to reduce current leakage from a heater element during pulse width modulation control of the heater element. Improvements are also disclosed in an application of negative pressure during a drain phase in peritoneal dialysis therapy, and to control an amount of intraperitoneal fluid accumulation during the therapy. Improvements in efficiency are also disclosed in movement of fluid into and out of a two-pump cassette and a heater bag of the peritoneal dialysis cycler, and in synchronization of operation of two or more pumps in the peritoneal dialysis cycler or other fluid handling devices using a multi-pump arrangement.

The invention relates to the technical field of magnetic pumps, and discloses a reverse driving impurity type magnetic pump which comprises a pump chamber, a water inlet, a water outlet and an impurity removal channel are formed outside the pump chamber, an impeller is arranged in the pump chamber, and the impeller is connected with an inner magnetic rotor shaft and is connected with an outer magnetic rotor shaft through a motor to drive rotation. Liquid in the water inlet axially flows into the pump chamber, a suction chamber is arranged in the water inlet and is a conical barrel with the cross section area gradually and uniformly shrunk, an inducer is arranged on the side, facing the water inlet, of the impeller, the inducer and the impeller coaxially rotate, the installation angle of blades of the inducer is small, and flow channels between the blades are long and wide. And the number of the blades is 2-4.

The utility model relates to the technical field of piezoelectric pumps, in particular to a novel fluid conveying device, which is characterized in that a vibration component is matched with a pump seat groove to define a pump cavity, the pump cavity is communicated with the outside through a pump inlet and a pump outlet which are arranged on a pump seat, and a first one-way valve and a second one-way valve are respectively arranged at the pump inlet and the pump outlet. The circulation holes in the first one-way valve and the second one-way valve are of a porous structure, and the pumping capacity of the fluid conveying device can be improved by increasing the total length of the edges of the circulation holes compared with a single-hole design with the same area. The fluid conveying device adopts a single-pump-cavity design, so that the overall size of the pump body can be obviously reduced, the pump inlet and the pump outlet are formed in the pump base and are provided with the first one-way valve and the second one-way valve respectively, and effective pumping-in and pumping-out of fluid in the same pump cavity are achieved; the fluid path is simplified, meanwhile, the turning process of the fluid is reduced, and therefore energy loss in the fluid pumping process is reduced.

The invention provides a sea water pump, and relates to the technical field of water pumps, the sea water pump comprises a pump shell, the pump shell is provided with a water inlet, a pumping chamber and a water outlet which are communicated in sequence, and the water inlet is perpendicular to the pump shell and detachably connected with a water inlet elbow; one end of the transmission shaft extends into the pumping chamber, and the other end rotationally penetrates through the bearing body to be connected with a driving motor; the main impeller is mounted on the transmission shaft and close to the water inlet; the auxiliary impeller is installed on the transmission shaft and located between the main impeller and the pump shell. The blades on the main impeller are made of copper, and the blades on the auxiliary impeller are made of rubber. A plurality of main impeller screw holes are distributed in the main impeller; the water inlet is connected with a filter. Due to the arrangement of the main blade screw holes, dynamic balance is conveniently achieved, pressure impact on the main impeller is reduced, and the main blade screw holes are used as auxiliary holes during assembly and disassembly. And the water inlet is connected with a filter, so that the normal work of the main impeller and the auxiliary impeller is prevented from being influenced due to the fact that large-volume soft marine organisms enter the pumping chamber.

The flexible impeller pump comprises a pump body and a motor, the pump body comprises a pump shell, an impeller and two adapting pipes, a pump chamber is formed in the pump shell, the inner side wall of the pump chamber comprises an arc surface, an outer convex surface and two inner concave surfaces, the two ends of the arc surface are connected with one ends of the two inner concave surfaces respectively, and the other ends of the two inner concave surfaces are connected with the motor. An inlet connecting pipe and an outlet connecting pipe which are communicated with the pump chamber are arranged on the outer side wall of the pump shell, the two adapter pipes are in threaded connection with the inlet connecting pipe and the outlet connecting pipe respectively, the impeller is rotationally arranged in the pump chamber and abuts against the arc surface, the inner concave surfaces and the outer convex surface, and the motor is arranged on the pump shell. And an output shaft of the motor is connected with the impeller.

A fluid handling cassette, such as that useable with an automated peritoneal dialysis (APD) cycler device or other infusion apparatus, may include a generally planar body having at least one pump chamber formed as a depression in a first side of the body and a plurality of flowpaths for a fluid that includes a channel. A patient line port may be arranged for connection to a patient line and be in fluid communication with the at least one pump chamber via at least a first one of said flowpaths, and an optional membrane may be attached to the first side of the body over the at least one pump chamber. In one embodiment, the membrane may have a pump chamber portion with an unstressed shape that generally conforms to the depression of the at least one pump chamber in the body and is arranged to be movable for movement of the fluid in a useable space of the at least one pump chamber. One or more spacers may be provided in the at least one pump chamber to prevent the membrane from contacting an inner wall of the at least one pump chamber. The patient line, a drain line, and / or a heater bag line may be positioned to be separately occludable in relation to one or more solution lines that are connectable to the cassette.

The utility model discloses a novel anti-liquid-carrying pressing pump which comprises a pump body and a pressing head, the pump body comprises a pump chamber, the upper end of the pump body is provided with a ventilation hole, a connecting rod is fixed below the pressing head, a pumping device is arranged in the pump chamber, the upper end of the pump body is fixedly provided with a lock cover, and a brake is arranged between the lock cover and the connecting rod. An angle limiting structure capable of limiting the rotating angle of the brake is arranged between the brake and the lock cover, a lifting structure capable of enabling the brake to ascend or descend when the brake rotates is arranged between the brake and the lock cover, and a sealing part is arranged on the brake. The pressing head is pressed down and is in threaded connection with the brake through the connecting rod to be locked on the brake, the brake is in a falling state, the sealing part blocks the upper end of the pump chamber to cut off communication between the ventilation hole and the pump chamber, and the solution is prevented from flowing out of the ventilation hole when the bottle is extruded or toppled. When the pressing head rotates and unlocks, the brake is driven to rotate and ascends to enable the sealing part to loosen the upper end of the pump chamber, so that the ventilation hole is communicated with the pump chamber for normal use of the pressing pump.

A positive displacement pump system can include a fluid end block, which can be configured to provide a pumping chamber and control a flow of a fluid through the positive displacement pump system. The fluid end block can include a first cylindrical wall defining a plunger bore extending partially through the fluid end block and a second cylindrical wall defining a fluid conveying cross bore that intersects the plunger bore defining a bore intersection rim. A portion of the first bore intersection rim can include a first toroidal surface.

A method for evaluating the pump actuation for a pump dispenser that includes two sub-units which can be moved manually towards one another and a pump which has a pump chamber that can be made smaller by moving the sub-units from a first end position into an actuated second end position. The force with which the sub-units are moved towards one another is detected by a force sensor during movement of the sub-units. The curve over time of the detected force is evaluated such that an increase in force is identified which is characteristic for reaching the actuated second end position. Depending on whether the increase in force was detected, a signal which is characteristic for the result is haptically, acoustically and / or visually output and / or transmitted via a wireless interface to an external display apparatus, by means of an output device.

The micropump comprises a silicon wafer, a first sealing piece and a second sealing piece, the silicon wafer is provided with a first face and a second face which are opposite to each other, a first groove used for forming a pump cavity is etched in the first face, and a plurality of grooves which meet the equal-width condition and are used for forming a moving body, an annular rib and a first valve body of an outlet valve are etched in the second face. The annular rib surrounds the moving body and is connected to a pump membrane around the moving body, and the first valve body is connected to a valve membrane of the outlet valve. The first sealing piece is fixed to the first face of the silicon wafer and covers the first groove to form a pump cavity. The second sealing sheet is fixed on the second surface of the silicon wafer. The second sealing sheet is provided with a connecting port used for connecting a driver at a position corresponding to the moving body. According to the micropump, through reasonable structural design, better etching uniformity can be obtained within shorter etching process time, the process cost is reduced, meanwhile, the product yield is improved, the situation that normal use in a low-temperature environment is affected due to the fact that much liquid is accumulated on the outlet valve is avoided, and the service life is prolonged.

An implantable LVAD is provided that includes a pump shaped so as to define a pump chamber. The pump includes a tubular linear motor, which includes a magnetic piston, which includes a reciprocating one-way valve configured to allow downstream blood flow and inhibit upstream blood flow; and a stator, which is configured to magnetically drive the magnetic piston with reciprocating motion, so as to pump blood downstream during downstream motion of the magnetic piston while the reciprocating one-way valve is closed. The pump further includes a spring, which is arranged to store energy during upstream motion of the magnetic piston and release the stored energy during the downstream motion of the magnetic piston. Control circuitry is configured to activate the tubular linear motor to provide pulsatile flow synchronized with cardiac cycles. Other configurations are also described.

A positive displacement pump system can include a fluid end block, which can be configured to provide a pumping chamber and control a flow of a fluid through the positive displacement pump system. The fluid end block can include a first cylindrical wall defining a plunger bore extending partially through the fluid end block and a second cylindrical wall defining a fluid conveying cross bore that intersects the plunger bore defining a bore intersection rim. A portion of the first bore intersection rim can include a first toroidal surface.

This invention discloses a scraper-type permanent magnet synchronous electromagnetic pump. The pump body has a pump chamber with an opening at one end. An end cover is sealed and fixed to the opening end of the pump chamber. A cam rotor is installed in the pump chamber. The rotating shafts at the front and rear ends of the cam rotor are rotatably connected to the end cover and the pump body, respectively. One end of the upper scraper and the lower scraper are fixed to the inner wall of the pump chamber by upper and lower torsion springs, respectively, dividing the pump chamber into a low-pressure chamber on the left and a high-pressure chamber on the right. The upper and lower torsion springs apply a spring force pointing towards the axis of the cam rotor to the upper and lower scrapers, respectively. The volume of the low-pressure chamber is larger than that of the high-pressure chamber. A winding is embedded in the inner wall at the bottom of the pump chamber or the inner surface of the end cover. Correspondingly, a pair of permanent magnets is embedded in the end face of the cam rotor near the winding. When the cam rotor rotates, the upper and lower scrapers swing, and their free ends always press against the outer circumferential surface of the cam rotor, scraping the fluid on the surface of the cam rotor. The cam-blade rotor, in cooperation with the upper and lower scrapers, improves the overall stability.

The invention relates to the technical field of fans, in particular to an integrated two-stage high-pressure Roots blower which comprises a pump body and two transmission shafts rotationally connected to the interior of the pump body, and further comprises a first-stage pump cavity formed in the pump body, a first-stage impeller used for conducting primary pressurization on gas is arranged in the first-stage pump cavity, and a second-stage impeller used for conducting secondary pressurization on gas is arranged in the second-stage pump cavity. A secondary pump cavity is formed in the pump body, a secondary impeller used for conducting secondary pressurization on gas is arranged in the secondary pump cavity, a blow-by channel communicated with the interior of the secondary pump cavity is formed in the primary pump cavity, and the blow-by channel is used for conveying the gas subjected to primary pressurization. The first-stage impeller and the second-stage impeller are connected to the outer surfaces of the two transmission shafts; and the isolation plates are connected to the two sides of the pump body through bolts, ventilation cavities allowing nitrogen to enter are formed in the isolation plates, sealing assemblies are arranged in the isolation plates and used for isolating the pump body, and flowing gas in the pump body can be cooled while the sealing assemblies are cooled through the nitrogen in the ventilation cavities.

The utility model discloses a novel piston-free pump head which comprises a pump chamber with an opening in the upper end, a resettable pump head body is installed in the pump chamber, a base cover used for being installed on a bottle opening is installed at the upper end of the pump chamber, a first protruding ring is arranged on the inner wall of the base cover, and the first protruding ring abuts against the outer wall of the pump head body. The installation gap between the base cover and the pump head is sealed, the pump head is pressed, air in the pump chamber enters the bottle through the air inlet hole, liquid in the bottle is discharged through the liquid outlet pipe and the pump head, the pump head is loosened, external air enters the pump chamber through the air supply channel, circulation is formed, an additional piston structure is not needed, and on the basis that normal liquid outlet is guaranteed, the working efficiency is improved. The structure is optimized, the production and assembly process is simplified, manufacturing is easier, the piston structure does not need to be damaged in the installation process, and the situation that the sealing effect of the piston structure becomes poor after repeated use, air leakage occurs, and consequently the product function is unstable is avoided.

A compact liquid-outlet system comprising a liquid pump device, a liquid-inlet flow channel, and a liquid-outlet flow channel and an oral cleaning method. The liquid pump device comprises a liquid pump cavity, a piston slidably disposed in the liquid pump cavity, and a piston rod. The piston rod extends through the liquid pump cavity in a liquid-tight manner and is connected to the piston. The piston divides a pump chamber of the liquid pump cavity into a rod chamber and a rodless chamber. The piston comprises a liquid-outlet one-way valve allowing only liquid to flow from the rod chamber to the rodless chamber. The liquid-inlet flow channel communicates with the rod chamber through a liquid-inlet one-way valve. The liquid-outlet flow channel communicates with the rodless chamber. This system eliminates the need of extra space for installing the liquid-outlet one-way valve, resulting in a more compact structure.

The invention belongs to the technical field of pump valves, particularly relates to an electromagnetic pump with vibration detection and lubricating liquid filtering functions and a using method, and aims to solve the problems that a magnetic force driving part and a pump cavity part of a traditional electromagnetic pump cannot be effectively isolated, an effective vibration detection means is lacked, and cooling lubricating liquid filtering is poor. A pump cavity is formed by a pump body, a pump cover and the like, a pump shaft is driven to rotate through magnetic force, and a mechanical seal isolates magnetic force driving and the pump cavity part; a detection structure is arranged between the base and the mounting plate and can detect the vibration frequency and amplitude; the liquid injection box is matched with the filtering structure to filter the cooling lubricating liquid, and the filter screen can be replaced by the rotating ring; the mounting plate vibrates to drive the rotating disc to rotate, and the filter screen is blown and cleaned in all directions; according to the electromagnetic pump, the service life can be prolonged, the vibration can be detected in real time, the cooling lubricating liquid is effectively filtered, and the filter screen is convenient to clean.

The invention relates to the technical field of medical instruments, and discloses an intelligent pressure feedback type peripheral blood vessel thrombus removal and autoblood transfusion system which comprises a negative pressure pump, one-way valves symmetrically arranged at one end of a negative pressure pump cabin, and a blood storage bag arranged on the outer side of the one-way valve at the outlet end of the negative pressure pump cabin. The separation mechanism is arranged on the outer side of the one-way valve at the inlet section of the negative pressure pump, and the bubble discharging mechanism is arranged in the separation mechanism and used for discharging bubbles from blood; the separating mechanism comprises a shell, a sliding groove formed in the top of the shell, a sliding block arranged in the sliding groove, and a reset spring arranged on the side, close to the negative pressure pump, of the sliding block, the sliding block moves along the sliding groove, and the sliding groove limits the moving range of the sliding block. By arranging the separating mechanism, the filtering part is divided into different working spaces, and the different working spaces can be switched, so that the situation that the whole equipment cannot be used due to blockage of a single filtering part is avoided.

An oral irrigator includes a drive assembly, a pump assembly, and a flexible membrane seal. The drive assembly is received within a housing. The pump assembly is positioned at least partially within a pump chamber. The pump assembly includes a piston and a connecting rod coupled to the drive assembly, the connecting rod movable between first and second positions through operation of the drive assembly. The flexible membrane seal extends from an interior surface of the pump chamber to the connecting rod to fluidly seal an open end of the pump chamber. The flexible membrane seal deforms from a first orientation to a second orientation as the connecting rod moves from the first position to the second position.

The invention provides a magnetically-driven two-stage water ring vacuum pump. The magnetically-driven two-stage water ring vacuum pump comprises a pump shell, a switching body and a magnetically-driven assembly, the pump shell is divided into two pump chambers through an adapter body, a rotatable rotor is eccentrically installed in each pump chamber, each rotor is provided with a plurality of rotor blades, and media conveyed from an inlet to an outlet of the pump chamber are compressed through rotation of the rotor blades. A magnetic unit is mounted in the rotor; a gas flow channel and a service liquid flow channel are arranged between the switching body and the two pump chambers, and the gas flow channel is used for inputting corrosive gas into the pump chambers for treatment and outputting the treated gas; the service liquid flow channel is used for conveying service liquid for treating corrosive gas into the pump chamber and outputting corrosion products; the magnetic driving assembly drives the rotor to rotate through a magnetic field. The water ring vacuum pump can effectively solve the problems of leakage, low pumping efficiency, component abrasion, remarkable reduction of residual pressure of gas and the like of the water ring vacuum pump.

The invention provides a shield pump, and belongs to the technical field of water pumps. A shield pump comprises a motor shell, a pump body, a junction box and an exhaust pipe, a pump cavity communicated with the outside is formed in the pump body, a rotating shaft with an air passing channel is arranged in the motor shell, the rotating shaft is sleeved with a shielding sleeve fixed in the motor shell, a cavity communicated with the pump cavity is formed between the rotating shaft and the shielding sleeve, and the exhaust pipe is communicated with the cavity. The lower end of the exhaust pipe is inserted into the top of the shielding sleeve and is welded and positioned on the shielding sleeve, the junction box is detachably connected to the top of the motor shell, a positioning hole coaxial with the exhaust pipe is formed in the junction box, the upper end of the exhaust pipe is inserted and positioned in the positioning hole and is in sealed connection with the positioning hole through a sealing piece, and a deflation bolt is inserted into the top of the junction box; and the deflation bolt is screwed at the upper end of the exhaust pipe. Through welding of the exhaust pipe and the shielding sleeve and the positioning hole of the junction box, the exhaust pipe and the rotating shaft, the shield pump which is more stable in operation is provided.

A submersible pump (10) suitable for pumping liquid that includes suspended solids such as sewage, includes a housing (12) with a motor (34) and a pump chamber (66). The motor rotates an impeller (72) within the pump chamber and a slicer (92) that operates to slice solids before they enter the pump chamber into smaller pieces. The impeller vanes (130) have a vane height (H) that is at least 30% of the impeller diameter (D). The impeller has a continuous annular donut shape open area (144) that maintains solids suspended and flowing with the liquid into and out of the pump chamber.